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Add suport for internal request (NOP and Query Request)

PATCH Superseded Sujit Reddy Thumma 3 participants 12 messages Jul 9, 2013 – Jul 19, 2013

Subsystems (2)
SCSI Arm Qualcomm mailing list

v3 of 5 Superseded Latest is v5 →

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Sujit Reddy Thumma

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v3 cover Add suport for internal request (NOP and Query Request)

This patch series replace the previous Query Request and NOP patches:
[PATCH 1/8] scsi: ufs: add support for query
[PATCH 6/8] scsi: ufs: Add support for sending NOP OUT UPIU [PATCH 7/8] scsi: ufs: Set fDeviceInit flag to initiate device initialization Major difference -

Sending the query request via the SCSI vendor specific command can cause a deadlock in case the SCSI command queue is blocked and we would like to send a query request (for example fDeviceInit in case of re-initialization). In addition, usage of a vendor specific SCSI command for UFS can cause future conflicts if this vendor specific command will be allocated for a different usage.

The new patch series gets an internal tag for NOP and query requests and do not involve the SCSI layer in UFS specific requests transfers. This design also resolves the possible deadlock mentioned above.

Changes from v2:
- Rebased on scsi-misc branche (commit 8c0eb596baa5)
- Minor addition to structure documentation in ufshcd.h
Changes from v1
- Allocate a tag for device management commands dynamically instead of reserving tag[MAX_QUEUE - 1].
- Changed the "internal_cmd" naming to "dev_cmd" to avoid confusion with other type of internal commands other than NOP and QUERY.

Dolev Raviv (1):
scsi: ufs: Set fDeviceInit flag to initiate device initialization

Sujit Reddy Thumma (1):
scsi: ufs: Add support for sending NOP OUT UPIU

 drivers/scsi/ufs/ufs.h    |  127 ++++++-
 drivers/scsi/ufs/ufshcd.c |  886 +++++++++++++++++++++++++++++++++++++++------
 drivers/scsi/ufs/ufshcd.h |   43 ++-
 drivers/scsi/ufs/ufshci.h |    2 +-
 4 files changed, 939 insertions(+), 119 deletions(-)
Signature · 2 lines
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation.
author
#1 lore raw

PATCH v3 1/2 scsi: ufs: Add support for sending NOP OUT UPIU

As part of device initialization sequence, sending NOP OUT UPIU and waiting for NOP IN UPIU response is mandatory. This confirms that the device UFS Transport (UTP) layer is functional and the host can configure the device with further commands. Add support for sending NOP OUT UPIU to check the device connection path and test whether the UTP layer on the device side is functional during initialization.

A tag is acquired from the SCSI tag map space in order to send the device management command. When the tag is acquired by internal command the scsi command is rejected with host busy flag in order to requeue the request. To avoid frequent collisions between internal commands and scsi commands the device management command tag is allocated in the opposite direction w.r.t block layer tag allocation.

Signed-off-by Sujit Reddy Thumma <[email protected]>
Signed-off-by Dolev Raviv <[email protected]>
---
 drivers/scsi/ufs/ufs.h    |   43 +++-
 drivers/scsi/ufs/ufshcd.c |  596 +++++++++++++++++++++++++++++++++++++--------
 drivers/scsi/ufs/ufshcd.h |   29 ++-
 3 files changed, 552 insertions(+), 116 deletions(-)
drivers/scsi/ufs/ufs.h +36 -7
index 139bc06..14c0a4e 100644
@@ -36,10 +36,16 @@
 #ifndef _UFS_H
 #define _UFS_H
 
+#include <linux/mutex.h>
+#include <linux/types.h>
+
 #define MAX_CDB_SIZE	16
+#define GENERAL_UPIU_REQUEST_SIZE 32
+#define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
+					(GENERAL_UPIU_REQUEST_SIZE))
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
-			((byte3 << 24) | (byte2 << 16) |\
+			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
 			 (byte1 << 8) | (byte0))
 
 /*

@@ -73,6 +79,7 @@ enum {
 	UPIU_TRANSACTION_TASK_RSP	= 0x24,
 	UPIU_TRANSACTION_READY_XFER	= 0x31,
 	UPIU_TRANSACTION_QUERY_RSP	= 0x36,
+	UPIU_TRANSACTION_REJECT_UPIU	= 0x3F,
 };
 
 /* UPIU Read/Write flags */

@@ -110,6 +117,12 @@ enum {
 	UPIU_COMMAND_SET_TYPE_QUERY	= 0x2,
 };
 
+/* UTP Transfer Request Command Offset */
+#define UPIU_COMMAND_TYPE_OFFSET	28
+
+/* Offset of the response code in the UPIU header */
+#define UPIU_RSP_CODE_OFFSET		8
+
 enum {
 	MASK_SCSI_STATUS	= 0xFF,
 	MASK_TASK_RESPONSE	= 0xFF00,

@@ -138,26 +151,32 @@ struct utp_upiu_header {
 
 /**
  * struct utp_upiu_cmd - Command UPIU structure
- * @header: UPIU header structure DW-0 to DW-2
  * @data_transfer_len: Data Transfer Length DW-3
  * @cdb: Command Descriptor Block CDB DW-4 to DW-7
  */
 struct utp_upiu_cmd {
-	struct utp_upiu_header header;
 	u32 exp_data_transfer_len;
 	u8 cdb[MAX_CDB_SIZE];
 };
 
 /**
- * struct utp_upiu_rsp - Response UPIU structure
- * @header: UPIU header DW-0 to DW-2
+ * struct utp_upiu_req - general upiu request structure
+ * @header:UPIU header structure DW-0 to DW-2
+ * @sc: fields structure for scsi command DW-3 to DW-7
+ */
+struct utp_upiu_req {
+	struct utp_upiu_header header;
+	struct utp_upiu_cmd sc;
+};
+
+/**
+ * struct utp_cmd_rsp - Response UPIU structure
  * @residual_transfer_count: Residual transfer count DW-3
  * @reserved: Reserved double words DW-4 to DW-7
  * @sense_data_len: Sense data length DW-8 U16
  * @sense_data: Sense data field DW-8 to DW-12
  */
-struct utp_upiu_rsp {
-	struct utp_upiu_header header;
+struct utp_cmd_rsp {
 	u32 residual_transfer_count;
 	u32 reserved[4];
 	u16 sense_data_len;

@@ -165,6 +184,16 @@ struct utp_upiu_rsp {
 };
 
 /**
+ * struct utp_upiu_rsp - general upiu response structure
+ * @header: UPIU header structure DW-0 to DW-2
+ * @sr: fields structure for scsi command DW-3 to DW-12
+ */
+struct utp_upiu_rsp {
+	struct utp_upiu_header header;
+	struct utp_cmd_rsp sr;
+};
+
+/**
  * struct utp_upiu_task_req - Task request UPIU structure
  * @header - UPIU header structure DW0 to DW-2
  * @input_param1: Input parameter 1 DW-3
drivers/scsi/ufs/ufshcd.c +489 -107

760 lines not on this page · raw message

drivers/scsi/ufs/ufshcd.h +27 -2
index 49590ee..c750a90 100644
@@ -68,6 +68,10 @@
 #define UFSHCD "ufshcd"
 #define UFSHCD_DRIVER_VERSION "0.2"
 
+enum dev_cmd_type {
+	DEV_CMD_TYPE_NOP		= 0x0,
+};
+
 /**
  * struct uic_command - UIC command structure
  * @command: UIC command

@@ -91,7 +95,7 @@ struct uic_command {
 /**
  * struct ufshcd_lrb - local reference block
  * @utr_descriptor_ptr: UTRD address of the command
- * @ucd_cmd_ptr: UCD address of the command
+ * @ucd_req_ptr: UCD address of the command
  * @ucd_rsp_ptr: Response UPIU address for this command
  * @ucd_prdt_ptr: PRDT address of the command
  * @cmd: pointer to SCSI command

@@ -101,10 +105,11 @@ struct uic_command {
  * @command_type: SCSI, UFS, Query.
  * @task_tag: Task tag of the command
  * @lun: LUN of the command
+ * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
  */
 struct ufshcd_lrb {
 	struct utp_transfer_req_desc *utr_descriptor_ptr;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
+	struct utp_upiu_req *ucd_req_ptr;
 	struct utp_upiu_rsp *ucd_rsp_ptr;
 	struct ufshcd_sg_entry *ucd_prdt_ptr;
 

@@ -116,8 +121,22 @@ struct ufshcd_lrb {
 	int command_type;
 	int task_tag;
 	unsigned int lun;
+	bool intr_cmd;
 };
 
+/**
+ * struct ufs_dev_cmd - all assosiated fields with device management commands
+ * @type: device management command type - Query, NOP OUT
+ * @lock: lock to allow one command at a time
+ * @complete: internal commands completion
+ * @tag_wq: wait queue until free command slot is available
+ */
+struct ufs_dev_cmd {
+	enum dev_cmd_type type;
+	struct mutex lock;
+	struct completion *complete;
+	wait_queue_head_t tag_wq;
+};
 
 /**
  * struct ufs_hba - per adapter private structure

@@ -131,6 +150,7 @@ struct ufshcd_lrb {
  * @host: Scsi_Host instance of the driver
  * @dev: device handle
  * @lrb: local reference block
+ * @lrb_in_use: lrb in use
  * @outstanding_tasks: Bits representing outstanding task requests
  * @outstanding_reqs: Bits representing outstanding transfer requests
  * @capabilities: UFS Controller Capabilities

@@ -146,6 +166,7 @@ struct ufshcd_lrb {
  * @intr_mask: Interrupt Mask Bits
  * @feh_workq: Work queue for fatal controller error handling
  * @errors: HBA errors
+ * @dev_cmd: ufs device management command information
  */
 struct ufs_hba {
 	void __iomem *mmio_base;

@@ -164,6 +185,7 @@ struct ufs_hba {
 	struct device *dev;
 
 	struct ufshcd_lrb *lrb;
+	unsigned long lrb_in_use;
 
 	unsigned long outstanding_tasks;
 	unsigned long outstanding_reqs;

@@ -188,6 +210,9 @@ struct ufs_hba {
 
 	/* HBA Errors */
 	u32 errors;
+
+	/* Device management request data */
+	struct ufs_dev_cmd dev_cmd;
 };
 
 #define ufshcd_writel(hba, val, reg)	\
Signature · 2 lines
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation.
Tested-by on v3 1/2
#2 lore raw

Re: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

Tested-by Maya Erez <[email protected]>
Quoted 1,026 lines

As part of device initialization sequence, sending NOP OUT UPIU and waiting for NOP IN UPIU response is mandatory. This confirms that the device UFS Transport (UTP) layer is functional and the host can configure the device with further commands. Add support for sending NOP OUT UPIU to check the device connection path and test whether the UTP layer on the device side is functional during initialization.

A tag is acquired from the SCSI tag map space in order to send the device management command. When the tag is acquired by internal command the scsi command is rejected with host busy flag in order to requeue the request. To avoid frequent collisions between internal commands and scsi commands the device management command tag is allocated in the opposite direction w.r.t block layer tag allocation.

Signed-off-by Sujit Reddy Thumma <[email protected]>
Signed-off-by Dolev Raviv <[email protected]>
---
 drivers/scsi/ufs/ufs.h    |   43 +++-
 drivers/scsi/ufs/ufshcd.c |  596
+++++++++++++++++++++++++++++++++++++--------
 drivers/scsi/ufs/ufshcd.h |   29 ++-
 3 files changed, 552 insertions(+), 116 deletions(-)
drivers/scsi/ufs/ufs.h +36 -7
index 139bc06..14c0a4e 100644
@@ -36,10 +36,16 @@
 #ifndef _UFS_H
 #define _UFS_H
 
+#include <linux/mutex.h>
+#include <linux/types.h>
+
 #define MAX_CDB_SIZE	16
+#define GENERAL_UPIU_REQUEST_SIZE 32
+#define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
+					(GENERAL_UPIU_REQUEST_SIZE))
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
-			((byte3 << 24) | (byte2 << 16) |\
+			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
 			 (byte1 << 8) | (byte0))
 
 /*

@@ -73,6 +79,7 @@ enum {
 	UPIU_TRANSACTION_TASK_RSP	= 0x24,
 	UPIU_TRANSACTION_READY_XFER	= 0x31,
 	UPIU_TRANSACTION_QUERY_RSP	= 0x36,
+	UPIU_TRANSACTION_REJECT_UPIU	= 0x3F,
 };
 
 /* UPIU Read/Write flags */

@@ -110,6 +117,12 @@ enum {
 	UPIU_COMMAND_SET_TYPE_QUERY	= 0x2,
 };
 
+/* UTP Transfer Request Command Offset */
+#define UPIU_COMMAND_TYPE_OFFSET	28
+
+/* Offset of the response code in the UPIU header */
+#define UPIU_RSP_CODE_OFFSET		8
+
 enum {
 	MASK_SCSI_STATUS	= 0xFF,
 	MASK_TASK_RESPONSE	= 0xFF00,

@@ -138,26 +151,32 @@ struct utp_upiu_header {
 
 /**
  * struct utp_upiu_cmd - Command UPIU structure
- * @header: UPIU header structure DW-0 to DW-2
  * @data_transfer_len: Data Transfer Length DW-3
  * @cdb: Command Descriptor Block CDB DW-4 to DW-7
  */
 struct utp_upiu_cmd {
-	struct utp_upiu_header header;
 	u32 exp_data_transfer_len;
 	u8 cdb[MAX_CDB_SIZE];
 };
 
 /**
- * struct utp_upiu_rsp - Response UPIU structure
- * @header: UPIU header DW-0 to DW-2
+ * struct utp_upiu_req - general upiu request structure
+ * @header:UPIU header structure DW-0 to DW-2
+ * @sc: fields structure for scsi command DW-3 to DW-7
+ */
+struct utp_upiu_req {
+	struct utp_upiu_header header;
+	struct utp_upiu_cmd sc;
+};
+
+/**
+ * struct utp_cmd_rsp - Response UPIU structure
  * @residual_transfer_count: Residual transfer count DW-3
  * @reserved: Reserved double words DW-4 to DW-7
  * @sense_data_len: Sense data length DW-8 U16
  * @sense_data: Sense data field DW-8 to DW-12
  */
-struct utp_upiu_rsp {
-	struct utp_upiu_header header;
+struct utp_cmd_rsp {
 	u32 residual_transfer_count;
 	u32 reserved[4];
 	u16 sense_data_len;

@@ -165,6 +184,16 @@ struct utp_upiu_rsp {
 };
 
 /**
+ * struct utp_upiu_rsp - general upiu response structure
+ * @header: UPIU header structure DW-0 to DW-2
+ * @sr: fields structure for scsi command DW-3 to DW-12
+ */
+struct utp_upiu_rsp {
+	struct utp_upiu_header header;
+	struct utp_cmd_rsp sr;
+};
+
+/**
  * struct utp_upiu_task_req - Task request UPIU structure
  * @header - UPIU header structure DW0 to DW-2
  * @input_param1: Input parameter 1 DW-3
drivers/scsi/ufs/ufshcd.c +46 -0
index b743bd6..3f482b6 100644
@@ -43,6 +43,11 @@
 /* UIC command timeout, unit: ms */
 #define UIC_CMD_TIMEOUT	500
 
+/* NOP OUT retries waiting for NOP IN response */
+#define NOP_OUT_RETRIES    10
+/* Timeout after 30 msecs if NOP OUT hangs without response */
+#define NOP_OUT_TIMEOUT    30 /* msecs */
+
 enum {
 	UFSHCD_MAX_CHANNEL	= 0,
 	UFSHCD_MAX_ID		= 1,

@@ -71,6 +76,47 @@ enum {
 	INT_AGGR_CONFIG,
 };
 
+/*
+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32
 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+
 /**
  * ufshcd_get_intr_mask - Get the interrupt bit mask

* @hba - Pointer to adapter instance

drivers/scsi/ufs/ufshcd.c +3 -8
@@ -191,18 +237,13 @@ static inline int ufshcd_get_uic_cmd_result(struct
 ufs_hba *hba)
 }
 
 /**
- * ufshcd_is_valid_req_rsp - checks if controller TR response is valid
+ * ufshcd_get_req_rsp - returns the TR response transaction type
  * @ucd_rsp_ptr: pointer to response UPIU
- *
- * This function checks the response UPIU for valid transaction type in
- * response field
- * Returns 0 on success, non-zero on failure
  */
 static inline int
-ufshcd_is_valid_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
+ufshcd_get_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
 {
-	return ((be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24) ==
-		 UPIU_TRANSACTION_RESPONSE) ? 0 : DID_ERROR << 16;
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24;
 }

/**

drivers/scsi/ufs/ufshcd.c +2 -2
@@ -299,9 +340,9 @@ static inline void ufshcd_copy_sense_data(struct
 ufshcd_lrb *lrbp)
 {
 	int len;
 	if (lrbp->sense_buffer) {
-		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
+		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
 		memcpy(lrbp->sense_buffer,
-			lrbp->ucd_rsp_ptr->sense_data,
+			lrbp->ucd_rsp_ptr->sr.sense_data,
 			min_t(int, len, SCSI_SENSE_BUFFERSIZE));
 	}

}

drivers/scsi/ufs/ufshcd.c +105 -53
@@ -519,76 +560,128 @@ static void ufshcd_disable_intr(struct ufs_hba
 *hba, u32 intrs)
 }
 
 /**
+ * ufshcd_prepare_req_desc_hdr() - Fills the requests header
+ * descriptor according to request
+ * @lrbp: pointer to local reference block
+ * @upiu_flags: flags required in the header
+ * @cmd_dir: requests data direction
+ */
+static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
+		u32 *upiu_flags, enum dma_data_direction cmd_dir)
+{
+	struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
+	u32 data_direction;
+	u32 dword_0;
+
+	if (cmd_dir == DMA_FROM_DEVICE) {
+		data_direction = UTP_DEVICE_TO_HOST;
+		*upiu_flags = UPIU_CMD_FLAGS_READ;
+	} else if (cmd_dir == DMA_TO_DEVICE) {
+		data_direction = UTP_HOST_TO_DEVICE;
+		*upiu_flags = UPIU_CMD_FLAGS_WRITE;
+	} else {
+		data_direction = UTP_NO_DATA_TRANSFER;
+		*upiu_flags = UPIU_CMD_FLAGS_NONE;
+	}
+
+	dword_0 = data_direction | (lrbp->command_type
+				<< UPIU_COMMAND_TYPE_OFFSET);
+	if (lrbp->intr_cmd)
+		dword_0 |= UTP_REQ_DESC_INT_CMD;
+
+	/* Transfer request descriptor header fields */
+	req_desc->header.dword_0 = cpu_to_le32(dword_0);
+
+	/*
+	 * assigning invalid value for command status. Controller
+	 * updates OCS on command completion, with the command
+	 * status
+	 */
+	req_desc->header.dword_2 =
+		cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+}
+
+/**
+ * ufshcd_prepare_utp_scsi_cmd_upiu() - fills the utp_transfer_req_desc,
+ * for scsi commands
+ * @lrbp - local reference block pointer
+ * @upiu_flags - flags
+ */
+static
+void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32
 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+				UPIU_TRANSACTION_COMMAND, upiu_flags,
+				lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+				UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);
+
+	/* Total EHS length and Data segment length will be zero */
+	ucd_req_ptr->header.dword_2 = 0;
+
+	ucd_req_ptr->sc.exp_data_transfer_len =
+		cpu_to_be32(lrbp->cmd->sdb.length);
+
+	memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd,
+		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
+}
+
+static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	memset(ucd_req_ptr, 0, sizeof(struct utp_upiu_req));
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 =
+		UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_NOP_OUT, 0, 0, lrbp->task_tag);
+}
+
+/**
  * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
+ * @hba - per adapter instance
  * @lrb - pointer to local reference block
  */
-static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
+static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb
 *lrbp)
 {
-	struct utp_transfer_req_desc *req_desc;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
-	u32 data_direction;
 	u32 upiu_flags;
-
-	ucd_cmd_ptr = lrbp->ucd_cmd_ptr;
-	req_desc = lrbp->utr_descriptor_ptr;
+	int ret = 0;
 
 	switch (lrbp->command_type) {
 	case UTP_CMD_TYPE_SCSI:
-		if (lrbp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
-			data_direction = UTP_DEVICE_TO_HOST;
-			upiu_flags = UPIU_CMD_FLAGS_READ;
-		} else if (lrbp->cmd->sc_data_direction == DMA_TO_DEVICE) {
-			data_direction = UTP_HOST_TO_DEVICE;
-			upiu_flags = UPIU_CMD_FLAGS_WRITE;
+		if (likely(lrbp->cmd)) {
+			ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
+					lrbp->cmd->sc_data_direction);
+			ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
 		} else {
-			data_direction = UTP_NO_DATA_TRANSFER;
-			upiu_flags = UPIU_CMD_FLAGS_NONE;
+			ret = -EINVAL;
 		}
-
-		/* Transfer request descriptor header fields */
-		req_desc->header.dword_0 =
-			cpu_to_le32(data_direction | UTP_SCSI_COMMAND);
-
-		/*
-		 * assigning invalid value for command status. Controller
-		 * updates OCS on command completion, with the command
-		 * status
-		 */
-		req_desc->header.dword_2 =
-			cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
-
-		/* command descriptor fields */
-		ucd_cmd_ptr->header.dword_0 =
-			cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_COMMAND,
-						      upiu_flags,
-						      lrbp->lun,
-						      lrbp->task_tag));
-		ucd_cmd_ptr->header.dword_1 =
-			cpu_to_be32(
-				UPIU_HEADER_DWORD(UPIU_COMMAND_SET_TYPE_SCSI,
-						  0,
-						  0,
-						  0));
-
-		/* Total EHS length and Data segment length will be zero */
-		ucd_cmd_ptr->header.dword_2 = 0;
-
-		ucd_cmd_ptr->exp_data_transfer_len =
-			cpu_to_be32(lrbp->cmd->sdb.length);
-
-		memcpy(ucd_cmd_ptr->cdb,
-		       lrbp->cmd->cmnd,
-		       (min_t(unsigned short,
-			      lrbp->cmd->cmd_len,
-			      MAX_CDB_SIZE)));
 		break;
 	case UTP_CMD_TYPE_DEV_MANAGE:
-		/* For query function implementation */
+		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+			ufshcd_prepare_utp_nop_upiu(lrbp);
+		else
+			ret = -EINVAL;
 		break;
 	case UTP_CMD_TYPE_UFS:
 		/* For UFS native command implementation */
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: UFS native command are not supported\n",
+			__func__);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: unknown command type: 0x%x\n",
+				__func__, lrbp->command_type);
 		break;
 	} /* end of switch */
+
+	return ret;

}

/**

drivers/scsi/ufs/ufshcd.c +19 -3
@@ -615,21 +708,37 @@ static int ufshcd_queuecommand(struct Scsi_Host
 *host, struct scsi_cmnd *cmd)
 		goto out;
 	}
 
+	/* acquire the tag to make sure device cmds don't use it */
+	if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) {
+		/*
+		 * Dev manage command in progress, requeue the command.
+		 * Requeuing the command helps in cases where the request *may*
+		 * find different tag instead of waiting for dev manage command
+		 * completion.
+		 */
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
 	lrbp = &hba->lrb[tag];
 
+	WARN_ON(lrbp->cmd);
 	lrbp->cmd = cmd;
 	lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
 	lrbp->sense_buffer = cmd->sense_buffer;
 	lrbp->task_tag = tag;
 	lrbp->lun = cmd->device->lun;
-
+	lrbp->intr_cmd = false;
 	lrbp->command_type = UTP_CMD_TYPE_SCSI;
 
 	/* form UPIU before issuing the command */
-	ufshcd_compose_upiu(lrbp);
+	ufshcd_compose_upiu(hba, lrbp);
 	err = ufshcd_map_sg(lrbp);
-	if (err)
+	if (err) {
+		lrbp->cmd = NULL;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
 		goto out;
+	}
 
 	/* issue command to the controller */
drivers/scsi/ufs/ufshcd.c +64 -0
 	spin_lock_irqsave(hba->host->host_lock, flags);

@@ -639,6 +748,198 @@ out:
 	return err;
 }
 
+static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, enum dev_cmd_type cmd_type, int tag)
+{
+	lrbp->cmd = NULL;
+	lrbp->sense_bufflen = 0;
+	lrbp->sense_buffer = NULL;
+	lrbp->task_tag = tag;
+	lrbp->lun = 0; /* device management cmd is not specific to any LUN */
+	lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
+	lrbp->intr_cmd = true; /* No interrupt aggregation */
+	hba->dev_cmd.type = cmd_type;
+
+	return ufshcd_compose_upiu(hba, lrbp);
+}
+
+static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, int max_timeout)
+{
+	int err = 0;
+	unsigned long timeout;
+	unsigned long flags;
+
+	timeout = wait_for_completion_timeout(hba->dev_cmd.complete,
+			msecs_to_jiffies(max_timeout));
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->dev_cmd.complete = NULL;
+	if (timeout)
+		err = ufshcd_get_tr_ocs(lrbp);
+	else
+		err = -ETIMEDOUT;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return err;
+}
+
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;
+
+	return err;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command

responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */

drivers/scsi/ufs/ufshcd.c +77 -0
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int resp;
+	int err = 0;
+
+	resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+	switch (resp) {
+	case UPIU_TRANSACTION_NOP_IN:
+		if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+			err = -EINVAL;
+			dev_err(hba->dev, "%s: unexpected response %x\n",
+					__func__, resp);
+		}
+		break;
+	case UPIU_TRANSACTION_REJECT_UPIU:
+		/* TODO: handle Reject UPIU Response */
+		err = -EPERM;
+		dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+				__func__);
+		break;
+	default:
+		err = -EINVAL;
+		dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+				__func__, resp);
+		break;
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+	int tag;
+	bool ret = false;
+	unsigned long tmp;
+
+	if (!tag_out)
+		goto out;
+
+	do {
+		tmp = ~hba->lrb_in_use;
+		tag = find_last_bit(&tmp, hba->nutrs);
+		if (tag >= hba->nutrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+	*tag_out = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: There is only one available tag for device management commands.

Thus
+ * synchronisation is the responsibilty of the user.
+ */

drivers/scsi/ufs/ufshcd.c +46 -0
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+		enum dev_cmd_type cmd_type, int timeout)
+{
+	struct ufshcd_lrb *lrbp;
+	int err;
+	int tag;
+	struct completion wait;
+	unsigned long flags;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by SCSI request timeout.
+	 */
+	wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+	init_completion(&wait);
+	lrbp = &hba->lrb[tag];
+	WARN_ON(lrbp->cmd);
+	err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+	if (unlikely(err))
+		goto out_put_tag;
+
+	hba->dev_cmd.complete = &wait;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+
+	if (err == -ETIMEDOUT) {
+		if (!ufshcd_clear_cmd(hba, tag))
+			err = -EAGAIN;
+	} else if (!err) {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		err = ufshcd_dev_cmd_completion(hba, lrbp);
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}
+
+out_put_tag:
+	ufshcd_put_dev_cmd_tag(hba, tag);
+	wake_up(&hba->dev_cmd.tag_wq);
+	return err;
+}
+
 /**
  * ufshcd_memory_alloc - allocate memory for host memory space data

structures
* @hba: per adapter instance

drivers/scsi/ufs/ufshcd.c +2 -2
@@ -774,8 +1075,8 @@ static void ufshcd_host_memory_configure(struct
 ufs_hba *hba)
 				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
 
 		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
-		hba->lrb[i].ucd_cmd_ptr =
-			(struct utp_upiu_cmd *)(cmd_descp + i);
+		hba->lrb[i].ucd_req_ptr =
+			(struct utp_upiu_req *)(cmd_descp + i);
 		hba->lrb[i].ucd_rsp_ptr =
 			(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
drivers/scsi/ufs/ufshcd.c +70 -21
 		hba->lrb[i].ucd_prdt_ptr =

@@ -961,6 +1262,38 @@ out:
 }
 
 /**
+ * ufshcd_validate_dev_connection() - Check device connection status
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_validate_dev_connection(struct ufs_hba *hba)
+{
+	int err = 0;
+	int retries;
+
+	mutex_lock(&hba->dev_cmd.lock);
+	for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+		err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+					       NOP_OUT_TIMEOUT);
+
+		if (!err || err == -ETIMEDOUT)
+			break;
+
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	if (err)
+		dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+	return err;
+}
+
+/**
  * ufshcd_do_reset - reset the host controller
  * @hba: per adapter instance
  *

@@ -986,13 +1319,20 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
 	for (tag = 0; tag < hba->nutrs; tag++) {
 		if (test_bit(tag, &hba->outstanding_reqs)) {
 			lrbp = &hba->lrb[tag];
-			scsi_dma_unmap(lrbp->cmd);
-			lrbp->cmd->result = DID_RESET << 16;
-			lrbp->cmd->scsi_done(lrbp->cmd);
-			lrbp->cmd = NULL;
+			if (lrbp->cmd) {
+				scsi_dma_unmap(lrbp->cmd);
+				lrbp->cmd->result = DID_RESET << 16;
+				lrbp->cmd->scsi_done(lrbp->cmd);
+				lrbp->cmd = NULL;
+				clear_bit_unlock(tag, &hba->lrb_in_use);
+			}
 		}
 	}
 
+	/* complete device management command */
+	if (hba->dev_cmd.complete)
+		complete(hba->dev_cmd.complete);
+
 	/* clear outstanding request/task bit maps */
 	hba->outstanding_reqs = 0;
 	hba->outstanding_tasks = 0;

@@ -1199,27 +1539,37 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba,
 struct ufshcd_lrb *lrbp)
 
 	switch (ocs) {
 	case OCS_SUCCESS:
-
 		/* check if the returned transfer response is valid */
-		result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
-		if (result) {
+		result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+		switch (result) {
+		case UPIU_TRANSACTION_RESPONSE:
+			/*
+			 * get the response UPIU result to extract
+			 * the SCSI command status
+			 */
+			result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+			/*
+			 * get the result based on SCSI status response
+			 * to notify the SCSI midlayer of the command status
+			 */
+			scsi_status = result & MASK_SCSI_STATUS;
+			result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+			break;
+		case UPIU_TRANSACTION_REJECT_UPIU:
+			/* TODO: handle Reject UPIU Response */
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Reject UPIU not fully implemented\n");
+			break;
+		default:
+			result = DID_ERROR << 16;
 			dev_err(hba->dev,
-				"Invalid response = %x\n", result);
+				"Unexpected request response code = %x\n",
+				result);
 			break;
 		}
-
-		/*
-		 * get the response UPIU result to extract
-		 * the SCSI command status
-		 */
-		result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
-
-		/*
-		 * get the result based on SCSI status response
-		 * to notify the SCSI midlayer of the command status
-		 */
-		scsi_status = result & MASK_SCSI_STATUS;
-		result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
 		break;
 	case OCS_ABORTED:
drivers/scsi/ufs/ufshcd.c +20 -11
 		result |= DID_ABORT << 16;

@@ -1259,28 +1609,37 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba
 *hba)
  */
 static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
 {
-	struct ufshcd_lrb *lrb;
+	struct ufshcd_lrb *lrbp;
+	struct scsi_cmnd *cmd;
 	unsigned long completed_reqs;
 	u32 tr_doorbell;
 	int result;
 	int index;
+	bool int_aggr_reset = false;
 
-	lrb = hba->lrb;
 	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
 	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
 
 	for (index = 0; index < hba->nutrs; index++) {
 		if (test_bit(index, &completed_reqs)) {
-
-			result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
-
-			if (lrb[index].cmd) {
-				scsi_dma_unmap(lrb[index].cmd);
-				lrb[index].cmd->result = result;
-				lrb[index].cmd->scsi_done(lrb[index].cmd);
-
+			lrbp = &hba->lrb[index];
+			cmd = lrbp->cmd;
+			/* Don't reset counters for interrupt cmd */
+			int_aggr_reset |= !lrbp->intr_cmd;
+
+			if (cmd) {
+				result = ufshcd_transfer_rsp_status(hba, lrbp);
+				scsi_dma_unmap(cmd);
+				cmd->result = result;
 				/* Mark completed command as NULL in LRB */
-				lrb[index].cmd = NULL;
+				lrbp->cmd = NULL;
+				clear_bit_unlock(index, &hba->lrb_in_use);
+				/* Do not touch lrbp after scsi done */
+				cmd->scsi_done(cmd);
+			} else if (lrbp->command_type ==
+					UTP_CMD_TYPE_DEV_MANAGE) {
+				if (hba->dev_cmd.complete)
+					complete(hba->dev_cmd.complete);
 			}
 		} /* end of if */
drivers/scsi/ufs/ufshcd.c +5 -1
 	} /* end of for */

@@ -1288,8 +1647,12 @@ static void ufshcd_transfer_req_compl(struct
 ufs_hba *hba)
 	/* clear corresponding bits of completed commands */
 	hba->outstanding_reqs ^= completed_reqs;
 
+	/* we might have free'd some tags above */
+	wake_up(&hba->dev_cmd.tag_wq);
+
 	/* Reset interrupt aggregation counters */
-	ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+	if (int_aggr_reset)
+		ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
 }

/**

drivers/scsi/ufs/ufshcd.c +6 -4
@@ -1432,10 +1795,10 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
 	task_req_upiup =
 		(struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
 	task_req_upiup->header.dword_0 =
-		cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
-					      lrbp->lun, lrbp->task_tag));
+		UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
+					      lrbp->lun, lrbp->task_tag);
 	task_req_upiup->header.dword_1 =
-	cpu_to_be32(UPIU_HEADER_DWORD(0, tm_function, 0, 0));
+		UPIU_HEADER_DWORD(0, tm_function, 0, 0);
 
 	task_req_upiup->input_param1 = lrbp->lun;
 	task_req_upiup->input_param1 =

@@ -1502,9 +1865,11 @@ static int ufshcd_device_reset(struct scsi_cmnd
 *cmd)
 			if (hba->lrb[pos].cmd) {
 				scsi_dma_unmap(hba->lrb[pos].cmd);
 				hba->lrb[pos].cmd->result =
-						DID_ABORT << 16;
+					DID_ABORT << 16;
 				hba->lrb[pos].cmd->scsi_done(cmd);
 				hba->lrb[pos].cmd = NULL;
+				clear_bit_unlock(pos, &hba->lrb_in_use);
+				wake_up(&hba->dev_cmd.tag_wq);
 			}
 		}
drivers/scsi/ufs/ufshcd.c +13 -2
 	} /* end of for */

@@ -1572,6 +1937,9 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
 	__clear_bit(tag, &hba->outstanding_reqs);
 	hba->lrb[tag].cmd = NULL;
 	spin_unlock_irqrestore(host->host_lock, flags);
+
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+	wake_up(&hba->dev_cmd.tag_wq);
 out:
 	return err;
 }

@@ -1587,8 +1955,16 @@ static void ufshcd_async_scan(void *data,
 async_cookie_t cookie)
 	int ret;
 
 	ret = ufshcd_link_startup(hba);
-	if (!ret)
-		scsi_scan_host(hba->host);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_validate_dev_connection(hba);
+	if (ret)
+		goto out;
+
+	scsi_scan_host(hba->host);
+out:
+	return;
 }

static struct scsi_host_template ufshcd_driver_template = {

drivers/scsi/ufs/ufshcd.c +6 -0
@@ -1744,6 +2120,12 @@ int ufshcd_init(struct device *dev, struct ufs_hba
 **hba_handle,
 	/* Initialize UIC command mutex */
 	mutex_init(&hba->uic_cmd_mutex);
 
+	/* Initialize mutex for device management commands */
+	mutex_init(&hba->dev_cmd.lock);
+
+	/* Initialize device management tag acquire wait queue */
+	init_waitqueue_head(&hba->dev_cmd.tag_wq);
+
 	/* IRQ registration */
 	err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
drivers/scsi/ufs/ufshcd.c +0 -0
 	if (err) {
drivers/scsi/ufs/ufshcd.h +10 -2
index 49590ee..c750a90 100644
@@ -68,6 +68,10 @@
 #define UFSHCD "ufshcd"
 #define UFSHCD_DRIVER_VERSION "0.2"
 
+enum dev_cmd_type {
+	DEV_CMD_TYPE_NOP		= 0x0,
+};
+
 /**
  * struct uic_command - UIC command structure
  * @command: UIC command

@@ -91,7 +95,7 @@ struct uic_command {
 /**
  * struct ufshcd_lrb - local reference block
  * @utr_descriptor_ptr: UTRD address of the command
- * @ucd_cmd_ptr: UCD address of the command
+ * @ucd_req_ptr: UCD address of the command
  * @ucd_rsp_ptr: Response UPIU address for this command
  * @ucd_prdt_ptr: PRDT address of the command
  * @cmd: pointer to SCSI command

@@ -101,10 +105,11 @@ struct uic_command {
  * @command_type: SCSI, UFS, Query.
  * @task_tag: Task tag of the command
  * @lun: LUN of the command
+ * @intr_cmd: Interrupt command (doesn't participate in interrupt
 aggregation)
  */
 struct ufshcd_lrb {
 	struct utp_transfer_req_desc *utr_descriptor_ptr;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
+	struct utp_upiu_req *ucd_req_ptr;
 	struct utp_upiu_rsp *ucd_rsp_ptr;
 	struct ufshcd_sg_entry *ucd_prdt_ptr;

@@ -116,8 +121,22 @@ struct ufshcd_lrb {
 	int command_type;
 	int task_tag;
 	unsigned int lun;
+	bool intr_cmd;
 };
 
+/**
+ * struct ufs_dev_cmd - all assosiated fields with device management

commands
+ * @type: device management command type - Query, NOP OUT
+ * @lock: lock to allow one command at a time
+ * @complete: internal commands completion
+ * @tag_wq: wait queue until free command slot is available
+ */

drivers/scsi/ufs/ufshcd.h +12 -1
+struct ufs_dev_cmd {
+	enum dev_cmd_type type;
+	struct mutex lock;
+	struct completion *complete;
+	wait_queue_head_t tag_wq;
+};
 
 /**
  * struct ufs_hba - per adapter private structure

@@ -131,6 +150,7 @@ struct ufshcd_lrb {
  * @host: Scsi_Host instance of the driver
  * @dev: device handle
  * @lrb: local reference block
+ * @lrb_in_use: lrb in use
  * @outstanding_tasks: Bits representing outstanding task requests
  * @outstanding_reqs: Bits representing outstanding transfer requests
  * @capabilities: UFS Controller Capabilities

@@ -146,6 +166,7 @@ struct ufshcd_lrb {
  * @intr_mask: Interrupt Mask Bits
  * @feh_workq: Work queue for fatal controller error handling
  * @errors: HBA errors
+ * @dev_cmd: ufs device management command information
  */
 struct ufs_hba {
 	void __iomem *mmio_base;

@@ -164,6 +185,7 @@ struct ufs_hba {
 	struct device *dev;
 
 	struct ufshcd_lrb *lrb;
+	unsigned long lrb_in_use;
 
 	unsigned long outstanding_tasks;
 	unsigned long outstanding_reqs;

@@ -188,6 +210,9 @@ struct ufs_hba {
 
 	/* HBA Errors */
 	u32 errors;
+
+	/* Device management request data */
+	struct ufs_dev_cmd dev_cmd;
 };
 
 #define ufshcd_writel(hba, val, reg)	\
--

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Signature · 3 lines
Maya Erez
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
#3 lore raw

RE: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

In reply to Sujit Reddy Thumma
Quoted 144 lines · Sujit Reddy Thumma

As part of device initialization sequence, sending NOP OUT UPIU and waiting for NOP IN UPIU response is mandatory. This confirms that the device UFS Transport (UTP) layer is functional and the host can configure the device with further commands. Add support for sending NOP OUT UPIU to check the device connection path and test whether the UTP layer on the device side is functional during initialization.

A tag is acquired from the SCSI tag map space in order to send the device management command. When the tag is acquired by internal command the scsi command is rejected with host busy flag in order to requeue the request. To avoid frequent collisions between internal commands and scsi commands the device management command tag is allocated in the opposite direction w.r.t block layer tag allocation.

Signed-off-by Sujit Reddy Thumma <[email protected]>
Signed-off-by Dolev Raviv <[email protected]>
---
 drivers/scsi/ufs/ufs.h    |   43 +++-
 drivers/scsi/ufs/ufshcd.c |  596 +++++++++++++++++++++++++++++++++++++--------
 drivers/scsi/ufs/ufshcd.h |   29 ++-
 3 files changed, 552 insertions(+), 116 deletions(-)
drivers/scsi/ufs/ufs.h +36 -7
index 139bc06..14c0a4e 100644
@@ -36,10 +36,16 @@
 #ifndef _UFS_H
 #define _UFS_H
 
+#include <linux/mutex.h>
+#include <linux/types.h>
+
 #define MAX_CDB_SIZE	16
+#define GENERAL_UPIU_REQUEST_SIZE 32
+#define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
+					(GENERAL_UPIU_REQUEST_SIZE))
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
-			((byte3 << 24) | (byte2 << 16) |\
+			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
 			 (byte1 << 8) | (byte0))
 
 /*

@@ -73,6 +79,7 @@ enum {
 	UPIU_TRANSACTION_TASK_RSP	= 0x24,
 	UPIU_TRANSACTION_READY_XFER	= 0x31,
 	UPIU_TRANSACTION_QUERY_RSP	= 0x36,
+	UPIU_TRANSACTION_REJECT_UPIU	= 0x3F,
 };
 
 /* UPIU Read/Write flags */

@@ -110,6 +117,12 @@ enum {
 	UPIU_COMMAND_SET_TYPE_QUERY	= 0x2,
 };
 
+/* UTP Transfer Request Command Offset */
+#define UPIU_COMMAND_TYPE_OFFSET	28
+
+/* Offset of the response code in the UPIU header */
+#define UPIU_RSP_CODE_OFFSET		8
+
 enum {
 	MASK_SCSI_STATUS	= 0xFF,
 	MASK_TASK_RESPONSE	= 0xFF00,

@@ -138,26 +151,32 @@ struct utp_upiu_header {
 
 /**
  * struct utp_upiu_cmd - Command UPIU structure
- * @header: UPIU header structure DW-0 to DW-2
  * @data_transfer_len: Data Transfer Length DW-3
  * @cdb: Command Descriptor Block CDB DW-4 to DW-7
  */
 struct utp_upiu_cmd {
-	struct utp_upiu_header header;
 	u32 exp_data_transfer_len;
 	u8 cdb[MAX_CDB_SIZE];
 };
 
 /**
- * struct utp_upiu_rsp - Response UPIU structure
- * @header: UPIU header DW-0 to DW-2
+ * struct utp_upiu_req - general upiu request structure
+ * @header:UPIU header structure DW-0 to DW-2
+ * @sc: fields structure for scsi command DW-3 to DW-7
+ */
+struct utp_upiu_req {
+	struct utp_upiu_header header;
+	struct utp_upiu_cmd sc;
+};
+
+/**
+ * struct utp_cmd_rsp - Response UPIU structure
  * @residual_transfer_count: Residual transfer count DW-3
  * @reserved: Reserved double words DW-4 to DW-7
  * @sense_data_len: Sense data length DW-8 U16
  * @sense_data: Sense data field DW-8 to DW-12
  */
-struct utp_upiu_rsp {
-	struct utp_upiu_header header;
+struct utp_cmd_rsp {
 	u32 residual_transfer_count;
 	u32 reserved[4];
 	u16 sense_data_len;

@@ -165,6 +184,16 @@ struct utp_upiu_rsp {
 };
 
 /**
+ * struct utp_upiu_rsp - general upiu response structure
+ * @header: UPIU header structure DW-0 to DW-2
+ * @sr: fields structure for scsi command DW-3 to DW-12
+ */
+struct utp_upiu_rsp {
+	struct utp_upiu_header header;
+	struct utp_cmd_rsp sr;
+};
+
+/**
  * struct utp_upiu_task_req - Task request UPIU structure
  * @header - UPIU header structure DW0 to DW-2
  * @input_param1: Input parameter 1 DW-3
drivers/scsi/ufs/ufshcd.c +8 -0
index b743bd6..3f482b6 100644
@@ -43,6 +43,11 @@
 /* UIC command timeout, unit: ms */
 #define UIC_CMD_TIMEOUT	500
 
+/* NOP OUT retries waiting for NOP IN response */
+#define NOP_OUT_RETRIES    10
+/* Timeout after 30 msecs if NOP OUT hangs without response */
+#define NOP_OUT_TIMEOUT    30 /* msecs */
+
 enum {
 	UFSHCD_MAX_CHANNEL	= 0,
 	UFSHCD_MAX_ID		= 1,

@@ -71,6 +76,47 @@ enum {
 	INT_AGGR_CONFIG,
 };
 
+/*
+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface

drivers/scsi/ufs/ufshcd.c enum { · line 91

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +10 -0
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)

I feel like this function's role is to wait for clearing register (specially, doorbells). If you really don't intend to apply other all register, I think it would better to change the function name. ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?
And if you like it, it could be more simple like below

static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us, unsigned int timeout_ms)

{
        unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
        /* wakeup within 50us of expiry */
        const unsigned int expiry = 50;

        while (ufshcd_readl(hba, reg) & mask) {
                usleep_range(interval_us, interval_us + expiry);
                if (time_after(jiffies, timeout)) {
                        if (ufshcd_readl(hba, reg) & mask)
                                return false;
                        else
                                return true;
                }
        }

        return true;
}
Quoted 338 lines
drivers/scsi/ufs/ufshcd.c +203 -66
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+
 /**
  * ufshcd_get_intr_mask - Get the interrupt bit mask
  * @hba - Pointer to adapter instance

@@ -191,18 +237,13 @@ static inline int ufshcd_get_uic_cmd_result(struct ufs_hba *hba)
 }
 
 /**
- * ufshcd_is_valid_req_rsp - checks if controller TR response is valid
+ * ufshcd_get_req_rsp - returns the TR response transaction type
  * @ucd_rsp_ptr: pointer to response UPIU
- *
- * This function checks the response UPIU for valid transaction type in
- * response field
- * Returns 0 on success, non-zero on failure
  */
 static inline int
-ufshcd_is_valid_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
+ufshcd_get_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
 {
-	return ((be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24) ==
-		 UPIU_TRANSACTION_RESPONSE) ? 0 : DID_ERROR << 16;
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24;
 }
 
 /**

@@ -299,9 +340,9 @@ static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
 {
 	int len;
 	if (lrbp->sense_buffer) {
-		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
+		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
 		memcpy(lrbp->sense_buffer,
-			lrbp->ucd_rsp_ptr->sense_data,
+			lrbp->ucd_rsp_ptr->sr.sense_data,
 			min_t(int, len, SCSI_SENSE_BUFFERSIZE));
 	}
 }

@@ -519,76 +560,128 @@ static void ufshcd_disable_intr(struct ufs_hba *hba, u32 intrs)
 }
 
 /**
+ * ufshcd_prepare_req_desc_hdr() - Fills the requests header
+ * descriptor according to request
+ * @lrbp: pointer to local reference block
+ * @upiu_flags: flags required in the header
+ * @cmd_dir: requests data direction
+ */
+static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
+		u32 *upiu_flags, enum dma_data_direction cmd_dir)
+{
+	struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
+	u32 data_direction;
+	u32 dword_0;
+
+	if (cmd_dir == DMA_FROM_DEVICE) {
+		data_direction = UTP_DEVICE_TO_HOST;
+		*upiu_flags = UPIU_CMD_FLAGS_READ;
+	} else if (cmd_dir == DMA_TO_DEVICE) {
+		data_direction = UTP_HOST_TO_DEVICE;
+		*upiu_flags = UPIU_CMD_FLAGS_WRITE;
+	} else {
+		data_direction = UTP_NO_DATA_TRANSFER;
+		*upiu_flags = UPIU_CMD_FLAGS_NONE;
+	}
+
+	dword_0 = data_direction | (lrbp->command_type
+				<< UPIU_COMMAND_TYPE_OFFSET);
+	if (lrbp->intr_cmd)
+		dword_0 |= UTP_REQ_DESC_INT_CMD;
+
+	/* Transfer request descriptor header fields */
+	req_desc->header.dword_0 = cpu_to_le32(dword_0);
+
+	/*
+	 * assigning invalid value for command status. Controller
+	 * updates OCS on command completion, with the command
+	 * status
+	 */
+	req_desc->header.dword_2 =
+		cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+}
+
+/**
+ * ufshcd_prepare_utp_scsi_cmd_upiu() - fills the utp_transfer_req_desc,
+ * for scsi commands
+ * @lrbp - local reference block pointer
+ * @upiu_flags - flags
+ */
+static
+void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+				UPIU_TRANSACTION_COMMAND, upiu_flags,
+				lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+				UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);
+
+	/* Total EHS length and Data segment length will be zero */
+	ucd_req_ptr->header.dword_2 = 0;
+
+	ucd_req_ptr->sc.exp_data_transfer_len =
+		cpu_to_be32(lrbp->cmd->sdb.length);
+
+	memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd,
+		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
+}
+
+static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	memset(ucd_req_ptr, 0, sizeof(struct utp_upiu_req));
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 =
+		UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_NOP_OUT, 0, 0, lrbp->task_tag);
+}
+
+/**
  * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
+ * @hba - per adapter instance
  * @lrb - pointer to local reference block
  */
-static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
+static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 {
-	struct utp_transfer_req_desc *req_desc;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
-	u32 data_direction;
 	u32 upiu_flags;
-
-	ucd_cmd_ptr = lrbp->ucd_cmd_ptr;
-	req_desc = lrbp->utr_descriptor_ptr;
+	int ret = 0;
 
 	switch (lrbp->command_type) {
 	case UTP_CMD_TYPE_SCSI:
-		if (lrbp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
-			data_direction = UTP_DEVICE_TO_HOST;
-			upiu_flags = UPIU_CMD_FLAGS_READ;
-		} else if (lrbp->cmd->sc_data_direction == DMA_TO_DEVICE) {
-			data_direction = UTP_HOST_TO_DEVICE;
-			upiu_flags = UPIU_CMD_FLAGS_WRITE;
+		if (likely(lrbp->cmd)) {
+			ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
+					lrbp->cmd->sc_data_direction);
+			ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
 		} else {
-			data_direction = UTP_NO_DATA_TRANSFER;
-			upiu_flags = UPIU_CMD_FLAGS_NONE;
+			ret = -EINVAL;
 		}
-
-		/* Transfer request descriptor header fields */
-		req_desc->header.dword_0 =
-			cpu_to_le32(data_direction | UTP_SCSI_COMMAND);
-
-		/*
-		 * assigning invalid value for command status. Controller
-		 * updates OCS on command completion, with the command
-		 * status
-		 */
-		req_desc->header.dword_2 =
-			cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
-
-		/* command descriptor fields */
-		ucd_cmd_ptr->header.dword_0 =
-			cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_COMMAND,
-						      upiu_flags,
-						      lrbp->lun,
-						      lrbp->task_tag));
-		ucd_cmd_ptr->header.dword_1 =
-			cpu_to_be32(
-				UPIU_HEADER_DWORD(UPIU_COMMAND_SET_TYPE_SCSI,
-						  0,
-						  0,
-						  0));
-
-		/* Total EHS length and Data segment length will be zero */
-		ucd_cmd_ptr->header.dword_2 = 0;
-
-		ucd_cmd_ptr->exp_data_transfer_len =
-			cpu_to_be32(lrbp->cmd->sdb.length);
-
-		memcpy(ucd_cmd_ptr->cdb,
-		       lrbp->cmd->cmnd,
-		       (min_t(unsigned short,
-			      lrbp->cmd->cmd_len,
-			      MAX_CDB_SIZE)));
 		break;
 	case UTP_CMD_TYPE_DEV_MANAGE:
-		/* For query function implementation */
+		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+			ufshcd_prepare_utp_nop_upiu(lrbp);
+		else
+			ret = -EINVAL;
 		break;
 	case UTP_CMD_TYPE_UFS:
 		/* For UFS native command implementation */
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: UFS native command are not supported\n",
+			__func__);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: unknown command type: 0x%x\n",
+				__func__, lrbp->command_type);
 		break;
 	} /* end of switch */
+
+	return ret;
 }
 
 /**

@@ -615,21 +708,37 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 		goto out;
 	}
 
+	/* acquire the tag to make sure device cmds don't use it */
+	if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) {
+		/*
+		 * Dev manage command in progress, requeue the command.
+		 * Requeuing the command helps in cases where the request *may*
+		 * find different tag instead of waiting for dev manage command
+		 * completion.
+		 */
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
 	lrbp = &hba->lrb[tag];
 
+	WARN_ON(lrbp->cmd);
 	lrbp->cmd = cmd;
 	lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
 	lrbp->sense_buffer = cmd->sense_buffer;
 	lrbp->task_tag = tag;
 	lrbp->lun = cmd->device->lun;
-
+	lrbp->intr_cmd = false;
 	lrbp->command_type = UTP_CMD_TYPE_SCSI;
 
 	/* form UPIU before issuing the command */
-	ufshcd_compose_upiu(lrbp);
+	ufshcd_compose_upiu(hba, lrbp);
 	err = ufshcd_map_sg(lrbp);
-	if (err)
+	if (err) {
+		lrbp->cmd = NULL;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
 		goto out;
+	}
 
 	/* issue command to the controller */
 	spin_lock_irqsave(hba->host->host_lock, flags);

@@ -639,6 +748,198 @@ out:
 	return err;
 }
 
+static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, enum dev_cmd_type cmd_type, int tag)
+{
+	lrbp->cmd = NULL;
+	lrbp->sense_bufflen = 0;
+	lrbp->sense_buffer = NULL;
+	lrbp->task_tag = tag;
+	lrbp->lun = 0; /* device management cmd is not specific to any LUN */
+	lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
+	lrbp->intr_cmd = true; /* No interrupt aggregation */
+	hba->dev_cmd.type = cmd_type;
+
+	return ufshcd_compose_upiu(hba, lrbp);
+}
+
+static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, int max_timeout)
+{
+	int err = 0;
+	unsigned long timeout;
+	unsigned long flags;
+
+	timeout = wait_for_completion_timeout(hba->dev_cmd.complete,
+			msecs_to_jiffies(max_timeout));
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->dev_cmd.complete = NULL;
+	if (timeout)
+		err = ufshcd_get_tr_ocs(lrbp);
+	else
+		err = -ETIMEDOUT;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return err;
+}
+
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);

drivers/scsi/ufs/ufshcd.c out: · line 806

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +10 -0
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);

4th argument should be (~mask) instead of '0', right? Actually, mask value involves the corresponding bit to be cleared. So, 4th argument may be unnecessary.

drivers/scsi/ufs/ufshcd.c out: · line 808

Quoted 2 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;

Also, checking the result can be involved in ufshcd_wait_for_register.

Quoted 119 lines
drivers/scsi/ufs/ufshcd.c +119 -0
+
+	return err;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int resp;
+	int err = 0;
+
+	resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+	switch (resp) {
+	case UPIU_TRANSACTION_NOP_IN:
+		if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+			err = -EINVAL;
+			dev_err(hba->dev, "%s: unexpected response %x\n",
+					__func__, resp);
+		}
+		break;
+	case UPIU_TRANSACTION_REJECT_UPIU:
+		/* TODO: handle Reject UPIU Response */
+		err = -EPERM;
+		dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+				__func__);
+		break;
+	default:
+		err = -EINVAL;
+		dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+				__func__, resp);
+		break;
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+	int tag;
+	bool ret = false;
+	unsigned long tmp;
+
+	if (!tag_out)
+		goto out;
+
+	do {
+		tmp = ~hba->lrb_in_use;
+		tag = find_last_bit(&tmp, hba->nutrs);
+		if (tag >= hba->nutrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+	*tag_out = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: There is only one available tag for device management commands. Thus
+ * synchronisation is the responsibilty of the user.
+ */
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+		enum dev_cmd_type cmd_type, int timeout)
+{
+	struct ufshcd_lrb *lrbp;
+	int err;
+	int tag;
+	struct completion wait;
+	unsigned long flags;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by SCSI request timeout.
+	 */
+	wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+	init_completion(&wait);
+	lrbp = &hba->lrb[tag];
+	WARN_ON(lrbp->cmd);
+	err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+	if (unlikely(err))
+		goto out_put_tag;
+
+	hba->dev_cmd.complete = &wait;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+

<snip>

drivers/scsi/ufs/ufshcd.c out: · line 935

Quoted 8 lines
drivers/scsi/ufs/ufshcd.c +8 -0
+	if (err == -ETIMEDOUT) {
+		if (!ufshcd_clear_cmd(hba, tag))
+			err = -EAGAIN;
+	} else if (!err) {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		err = ufshcd_dev_cmd_completion(hba, lrbp);
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}

</snip>
I think sniped part can be involved in ufshcd_wait_for_dev_cmd. How do you think about that?

Quoted 25 lines
drivers/scsi/ufs/ufshcd.c +9 -2
+
+out_put_tag:
+	ufshcd_put_dev_cmd_tag(hba, tag);
+	wake_up(&hba->dev_cmd.tag_wq);
+	return err;
+}
+
 /**
  * ufshcd_memory_alloc - allocate memory for host memory space data structures
  * @hba: per adapter instance

@@ -774,8 +1075,8 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
 				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
 
 		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
-		hba->lrb[i].ucd_cmd_ptr =
-			(struct utp_upiu_cmd *)(cmd_descp + i);
+		hba->lrb[i].ucd_req_ptr =
+			(struct utp_upiu_req *)(cmd_descp + i);
 		hba->lrb[i].ucd_rsp_ptr =
 			(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
 		hba->lrb[i].ucd_prdt_ptr =

@@ -961,6 +1262,38 @@ out:
 }
 
 /**

drivers/scsi/ufs/ufshcd.c out: · line 1274

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +10 -0
+ * ufshcd_validate_dev_connection() - Check device connection status
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_validate_dev_connection(struct ufs_hba *hba)

I think ufshcd_verify_dev_init is close to standard description.

Quoted 30 lines
drivers/scsi/ufs/ufshcd.c +22 -1
+{
+	int err = 0;
+	int retries;
+
+	mutex_lock(&hba->dev_cmd.lock);
+	for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+		err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+					       NOP_OUT_TIMEOUT);
+
+		if (!err || err == -ETIMEDOUT)
+			break;
+
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	if (err)
+		dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+	return err;
+}
+
+/**
  * ufshcd_do_reset - reset the host controller
  * @hba: per adapter instance
  *

@@ -986,13 +1319,20 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
 	for (tag = 0; tag < hba->nutrs; tag++) {
 		if (test_bit(tag, &hba->outstanding_reqs)) {
 			lrbp = &hba->lrb[tag];
-			scsi_dma_unmap(lrbp->cmd);

drivers/scsi/ufs/ufshcd.c static int ufshcd_do_reset(struct ufs_hba *hba) · line 1328

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +7 -3
-			lrbp->cmd->result = DID_RESET << 16;
-			lrbp->cmd->scsi_done(lrbp->cmd);
-			lrbp->cmd = NULL;
+			if (lrbp->cmd) {
+				scsi_dma_unmap(lrbp->cmd);
+				lrbp->cmd->result = DID_RESET << 16;
+				lrbp->cmd->scsi_done(lrbp->cmd);
+				lrbp->cmd = NULL;
+				clear_bit_unlock(tag, &hba->lrb_in_use);
+			}

I know above.
But there is no relation to this patch.
Can be it moved to scsi: ufs: Fix device and host reset methods?

Quoted 11 lines
drivers/scsi/ufs/ufshcd.c +4 -0
 		}
 	}
 
+	/* complete device management command */
+	if (hba->dev_cmd.complete)
+		complete(hba->dev_cmd.complete);
+
 	/* clear outstanding request/task bit maps */
 	hba->outstanding_reqs = 0;
 	hba->outstanding_tasks = 0;

drivers/scsi/ufs/ufshcd.c ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) · line 1542

Quoted 5 lines
drivers/scsi/ufs/ufshcd.c +0 -1
@@ -1199,27 +1539,37 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 
 	switch (ocs) {
 	case OCS_SUCCESS:
-
 		/* check if the returned transfer response is valid */

As replaced with new function, comment isn't valid. Remove or "get the TR response transaction type" seems proper.

Quoted 99 lines
drivers/scsi/ufs/ufshcd.c +47 -27
-		result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
-		if (result) {
+		result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+		switch (result) {
+		case UPIU_TRANSACTION_RESPONSE:
+			/*
+			 * get the response UPIU result to extract
+			 * the SCSI command status
+			 */
+			result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+			/*
+			 * get the result based on SCSI status response
+			 * to notify the SCSI midlayer of the command status
+			 */
+			scsi_status = result & MASK_SCSI_STATUS;
+			result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+			break;
+		case UPIU_TRANSACTION_REJECT_UPIU:
+			/* TODO: handle Reject UPIU Response */
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Reject UPIU not fully implemented\n");
+			break;
+		default:
+			result = DID_ERROR << 16;
 			dev_err(hba->dev,
-				"Invalid response = %x\n", result);
+				"Unexpected request response code = %x\n",
+				result);
 			break;
 		}
-
-		/*
-		 * get the response UPIU result to extract
-		 * the SCSI command status
-		 */
-		result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
-
-		/*
-		 * get the result based on SCSI status response
-		 * to notify the SCSI midlayer of the command status
-		 */
-		scsi_status = result & MASK_SCSI_STATUS;
-		result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
 		break;
 	case OCS_ABORTED:
 		result |= DID_ABORT << 16;

@@ -1259,28 +1609,37 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
  */
 static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
 {
-	struct ufshcd_lrb *lrb;
+	struct ufshcd_lrb *lrbp;
+	struct scsi_cmnd *cmd;
 	unsigned long completed_reqs;
 	u32 tr_doorbell;
 	int result;
 	int index;
+	bool int_aggr_reset = false;
 
-	lrb = hba->lrb;
 	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
 	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
 
 	for (index = 0; index < hba->nutrs; index++) {
 		if (test_bit(index, &completed_reqs)) {
-
-			result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
-
-			if (lrb[index].cmd) {
-				scsi_dma_unmap(lrb[index].cmd);
-				lrb[index].cmd->result = result;
-				lrb[index].cmd->scsi_done(lrb[index].cmd);
-
+			lrbp = &hba->lrb[index];
+			cmd = lrbp->cmd;
+			/* Don't reset counters for interrupt cmd */
+			int_aggr_reset |= !lrbp->intr_cmd;
+
+			if (cmd) {
+				result = ufshcd_transfer_rsp_status(hba, lrbp);
+				scsi_dma_unmap(cmd);
+				cmd->result = result;
 				/* Mark completed command as NULL in LRB */
-				lrb[index].cmd = NULL;
+				lrbp->cmd = NULL;
+				clear_bit_unlock(index, &hba->lrb_in_use);
+				/* Do not touch lrbp after scsi done */
+				cmd->scsi_done(cmd);
+			} else if (lrbp->command_type ==
+					UTP_CMD_TYPE_DEV_MANAGE) {
+				if (hba->dev_cmd.complete)
+					complete(hba->dev_cmd.complete);
 			}
 		} /* end of if */
 	} /* end of for */

drivers/scsi/ufs/ufshcd.c static void ufshcd_transfer_req_compl(struct ufs_hba *hba) · line 1655

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +5 -1
@@ -1288,8 +1647,12 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
 	/* clear corresponding bits of completed commands */
 	hba->outstanding_reqs ^= completed_reqs;
 
+	/* we might have free'd some tags above */
+	wake_up(&hba->dev_cmd.tag_wq);
+
 	/* Reset interrupt aggregation counters */
-	ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+	if (int_aggr_reset)
+		ufshcd_config_int_aggr(hba, INT_AGGR_RESET);

Do you assume that interrupt command(device management command) is completed alone? Of course, interrupt command is not counted in aggregation unlike regular command. We need to consider that interrupt command comes along with regular command? If right, ufshcd_config_int_aggr should not be skipped.

Thanks,
Seungwon Jeon

Quoted 174 lines
drivers/scsi/ufs/ufshcd.c +25 -6
 }
 
 /**

@@ -1432,10 +1795,10 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
 	task_req_upiup =
 		(struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
 	task_req_upiup->header.dword_0 =
-		cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
-					      lrbp->lun, lrbp->task_tag));
+		UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
+					      lrbp->lun, lrbp->task_tag);
 	task_req_upiup->header.dword_1 =
-	cpu_to_be32(UPIU_HEADER_DWORD(0, tm_function, 0, 0));
+		UPIU_HEADER_DWORD(0, tm_function, 0, 0);
 
 	task_req_upiup->input_param1 = lrbp->lun;
 	task_req_upiup->input_param1 =

@@ -1502,9 +1865,11 @@ static int ufshcd_device_reset(struct scsi_cmnd *cmd)
 			if (hba->lrb[pos].cmd) {
 				scsi_dma_unmap(hba->lrb[pos].cmd);
 				hba->lrb[pos].cmd->result =
-						DID_ABORT << 16;
+					DID_ABORT << 16;
 				hba->lrb[pos].cmd->scsi_done(cmd);
 				hba->lrb[pos].cmd = NULL;
+				clear_bit_unlock(pos, &hba->lrb_in_use);
+				wake_up(&hba->dev_cmd.tag_wq);
 			}
 		}
 	} /* end of for */

@@ -1572,6 +1937,9 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
 	__clear_bit(tag, &hba->outstanding_reqs);
 	hba->lrb[tag].cmd = NULL;
 	spin_unlock_irqrestore(host->host_lock, flags);
+
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+	wake_up(&hba->dev_cmd.tag_wq);
 out:
 	return err;
 }

@@ -1587,8 +1955,16 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
 	int ret;
 
 	ret = ufshcd_link_startup(hba);
-	if (!ret)
-		scsi_scan_host(hba->host);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_validate_dev_connection(hba);
+	if (ret)
+		goto out;
+
+	scsi_scan_host(hba->host);
+out:
+	return;
 }
 
 static struct scsi_host_template ufshcd_driver_template = {

@@ -1744,6 +2120,12 @@ int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
 	/* Initialize UIC command mutex */
 	mutex_init(&hba->uic_cmd_mutex);
 
+	/* Initialize mutex for device management commands */
+	mutex_init(&hba->dev_cmd.lock);
+
+	/* Initialize device management tag acquire wait queue */
+	init_waitqueue_head(&hba->dev_cmd.tag_wq);
+
 	/* IRQ registration */
 	err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
 	if (err) {
drivers/scsi/ufs/ufshcd.h +27 -3
index 49590ee..c750a90 100644
@@ -68,6 +68,10 @@
 #define UFSHCD "ufshcd"
 #define UFSHCD_DRIVER_VERSION "0.2"
 
+enum dev_cmd_type {
+	DEV_CMD_TYPE_NOP		= 0x0,
+};
+
 /**
  * struct uic_command - UIC command structure
  * @command: UIC command

@@ -91,7 +95,7 @@ struct uic_command {
 /**
  * struct ufshcd_lrb - local reference block
  * @utr_descriptor_ptr: UTRD address of the command
- * @ucd_cmd_ptr: UCD address of the command
+ * @ucd_req_ptr: UCD address of the command
  * @ucd_rsp_ptr: Response UPIU address for this command
  * @ucd_prdt_ptr: PRDT address of the command
  * @cmd: pointer to SCSI command

@@ -101,10 +105,11 @@ struct uic_command {
  * @command_type: SCSI, UFS, Query.
  * @task_tag: Task tag of the command
  * @lun: LUN of the command
+ * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
  */
 struct ufshcd_lrb {
 	struct utp_transfer_req_desc *utr_descriptor_ptr;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
+	struct utp_upiu_req *ucd_req_ptr;
 	struct utp_upiu_rsp *ucd_rsp_ptr;
 	struct ufshcd_sg_entry *ucd_prdt_ptr;
 

@@ -116,8 +121,22 @@ struct ufshcd_lrb {
 	int command_type;
 	int task_tag;
 	unsigned int lun;
+	bool intr_cmd;
 };
 
+/**
+ * struct ufs_dev_cmd - all assosiated fields with device management commands
+ * @type: device management command type - Query, NOP OUT
+ * @lock: lock to allow one command at a time
+ * @complete: internal commands completion
+ * @tag_wq: wait queue until free command slot is available
+ */
+struct ufs_dev_cmd {
+	enum dev_cmd_type type;
+	struct mutex lock;
+	struct completion *complete;
+	wait_queue_head_t tag_wq;
+};
 
 /**
  * struct ufs_hba - per adapter private structure

@@ -131,6 +150,7 @@ struct ufshcd_lrb {
  * @host: Scsi_Host instance of the driver
  * @dev: device handle
  * @lrb: local reference block
+ * @lrb_in_use: lrb in use
  * @outstanding_tasks: Bits representing outstanding task requests
  * @outstanding_reqs: Bits representing outstanding transfer requests
  * @capabilities: UFS Controller Capabilities

@@ -146,6 +166,7 @@ struct ufshcd_lrb {
  * @intr_mask: Interrupt Mask Bits
  * @feh_workq: Work queue for fatal controller error handling
  * @errors: HBA errors
+ * @dev_cmd: ufs device management command information
  */
 struct ufs_hba {
 	void __iomem *mmio_base;

@@ -164,6 +185,7 @@ struct ufs_hba {
 	struct device *dev;
 
 	struct ufshcd_lrb *lrb;
+	unsigned long lrb_in_use;
 
 	unsigned long outstanding_tasks;
 	unsigned long outstanding_reqs;

@@ -188,6 +210,9 @@ struct ufs_hba {
 
 	/* HBA Errors */
 	u32 errors;
+
+	/* Device management request data */
+	struct ufs_dev_cmd dev_cmd;
 };
 
 #define ufshcd_writel(hba, val, reg)	\
--

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author
#4 lore raw

Re: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

Quoted 142 lines · Seungwon Jeon
Quoted 141 lines · Sujit Reddy Thumma

As part of device initialization sequence, sending NOP OUT UPIU and waiting for NOP IN UPIU response is mandatory. This confirms that the device UFS Transport (UTP) layer is functional and the host can configure the device with further commands. Add support for sending NOP OUT UPIU to check the device connection path and test whether the UTP layer on the device side is functional during initialization.

A tag is acquired from the SCSI tag map space in order to send the device management command. When the tag is acquired by internal command the scsi command is rejected with host busy flag in order to requeue the request. To avoid frequent collisions between internal commands and scsi commands the device management command tag is allocated in the opposite direction w.r.t block layer tag allocation.

Signed-off-by Sujit Reddy Thumma <[email protected]>
Signed-off-by Dolev Raviv <[email protected]>
---
  drivers/scsi/ufs/ufs.h    |   43 +++-
  drivers/scsi/ufs/ufshcd.c |  596 +++++++++++++++++++++++++++++++++++++--------
  drivers/scsi/ufs/ufshcd.h |   29 ++-
  3 files changed, 552 insertions(+), 116 deletions(-)
drivers/scsi/ufs/ufs.h +36 -7
index 139bc06..14c0a4e 100644
@@ -36,10 +36,16 @@
  #ifndef _UFS_H
  #define _UFS_H
 
+#include <linux/mutex.h>
+#include <linux/types.h>
+
  #define MAX_CDB_SIZE	16
+#define GENERAL_UPIU_REQUEST_SIZE 32
+#define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
+					(GENERAL_UPIU_REQUEST_SIZE))
 
  #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
-			((byte3 << 24) | (byte2 << 16) |\
+			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
  			 (byte1 << 8) | (byte0))
 
  /*

@@ -73,6 +79,7 @@ enum {
  	UPIU_TRANSACTION_TASK_RSP	= 0x24,
  	UPIU_TRANSACTION_READY_XFER	= 0x31,
  	UPIU_TRANSACTION_QUERY_RSP	= 0x36,
+	UPIU_TRANSACTION_REJECT_UPIU	= 0x3F,
  };
 
  /* UPIU Read/Write flags */

@@ -110,6 +117,12 @@ enum {
  	UPIU_COMMAND_SET_TYPE_QUERY	= 0x2,
  };
 
+/* UTP Transfer Request Command Offset */
+#define UPIU_COMMAND_TYPE_OFFSET	28
+
+/* Offset of the response code in the UPIU header */
+#define UPIU_RSP_CODE_OFFSET		8
+
  enum {
  	MASK_SCSI_STATUS	= 0xFF,
  	MASK_TASK_RESPONSE	= 0xFF00,

@@ -138,26 +151,32 @@ struct utp_upiu_header {
 
  /**
   * struct utp_upiu_cmd - Command UPIU structure
- * @header: UPIU header structure DW-0 to DW-2
   * @data_transfer_len: Data Transfer Length DW-3
   * @cdb: Command Descriptor Block CDB DW-4 to DW-7
   */
  struct utp_upiu_cmd {
-	struct utp_upiu_header header;
  	u32 exp_data_transfer_len;
  	u8 cdb[MAX_CDB_SIZE];
  };
 
  /**
- * struct utp_upiu_rsp - Response UPIU structure
- * @header: UPIU header DW-0 to DW-2
+ * struct utp_upiu_req - general upiu request structure
+ * @header:UPIU header structure DW-0 to DW-2
+ * @sc: fields structure for scsi command DW-3 to DW-7
+ */
+struct utp_upiu_req {
+	struct utp_upiu_header header;
+	struct utp_upiu_cmd sc;
+};
+
+/**
+ * struct utp_cmd_rsp - Response UPIU structure
   * @residual_transfer_count: Residual transfer count DW-3
   * @reserved: Reserved double words DW-4 to DW-7
   * @sense_data_len: Sense data length DW-8 U16
   * @sense_data: Sense data field DW-8 to DW-12
   */
-struct utp_upiu_rsp {
-	struct utp_upiu_header header;
+struct utp_cmd_rsp {
  	u32 residual_transfer_count;
  	u32 reserved[4];
  	u16 sense_data_len;

@@ -165,6 +184,16 @@ struct utp_upiu_rsp {
  };
 
  /**
+ * struct utp_upiu_rsp - general upiu response structure
+ * @header: UPIU header structure DW-0 to DW-2
+ * @sr: fields structure for scsi command DW-3 to DW-12
+ */
+struct utp_upiu_rsp {
+	struct utp_upiu_header header;
+	struct utp_cmd_rsp sr;
+};
+
+/**
   * struct utp_upiu_task_req - Task request UPIU structure
   * @header - UPIU header structure DW0 to DW-2
   * @input_param1: Input parameter 1 DW-3
drivers/scsi/ufs/ufshcd.c +5 -0
index b743bd6..3f482b6 100644
@@ -43,6 +43,11 @@
  /* UIC command timeout, unit: ms */
  #define UIC_CMD_TIMEOUT	500
 
+/* NOP OUT retries waiting for NOP IN response */
+#define NOP_OUT_RETRIES    10
+/* Timeout after 30 msecs if NOP OUT hangs without response */
+#define NOP_OUT_TIMEOUT    30 /* msecs */
+
  enum {
  	UFSHCD_MAX_CHANNEL	= 0,
  	UFSHCD_MAX_ID		= 1,

@@ -71,6 +76,47 @@ enum {
  	INT_AGGR_CONFIG,
  };
Quoted 16 lines

drivers/scsi/ufs/ufshcd.c enum { · line 91

Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +13 -0
+/*
+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)

I feel like this function's role is to wait for clearing register (specially, doorbells). If you really don't intend to apply other all register, I think it would better to change the function name. ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?

Although, this API is introduced in this patch and used only for clearing the doorbell, I have intentionally made it generic to avoid duplication of wait condition code in future (not just clearing but also for setting a bit). For example, when we write to HCE.ENABLE we wait for it turn to 1.

Quoted 7 lines

And if you like it, it could be more simple like below

static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us, unsigned int timeout_ms)

{
         unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);

Jiffies on 100Hz systems have minimum granularity of 10ms. So we really wait for more 10ms even though the timeout_ms < 10ms.

Quoted 8 lines
         /* wakeup within 50us of expiry */
         const unsigned int expiry = 50;

         while (ufshcd_readl(hba, reg) & mask) {
                 usleep_range(interval_us, interval_us + expiry);
                 if (time_after(jiffies, timeout)) {
                         if (ufshcd_readl(hba, reg) & mask)
                                 return false;

I really want the caller to decide on what to do after the timeout. This helps in error handling cases where we try to clear off the entire door-bell register but only a few of the bits are cleared after timeout.

Quoted 348 lines
                         else
                                 return true;
                 }
         }

         return true;
}
Quoted 341 lines
drivers/scsi/ufs/ufshcd.c +206 -66
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+
  /**
   * ufshcd_get_intr_mask - Get the interrupt bit mask
   * @hba - Pointer to adapter instance

@@ -191,18 +237,13 @@ static inline int ufshcd_get_uic_cmd_result(struct ufs_hba *hba)
  }
 
  /**
- * ufshcd_is_valid_req_rsp - checks if controller TR response is valid
+ * ufshcd_get_req_rsp - returns the TR response transaction type
   * @ucd_rsp_ptr: pointer to response UPIU
- *
- * This function checks the response UPIU for valid transaction type in
- * response field
- * Returns 0 on success, non-zero on failure
   */
  static inline int
-ufshcd_is_valid_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
+ufshcd_get_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
  {
-	return ((be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24) ==
-		 UPIU_TRANSACTION_RESPONSE) ? 0 : DID_ERROR << 16;
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24;
  }
 
  /**

@@ -299,9 +340,9 @@ static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
  {
  	int len;
  	if (lrbp->sense_buffer) {
-		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
+		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
  		memcpy(lrbp->sense_buffer,
-			lrbp->ucd_rsp_ptr->sense_data,
+			lrbp->ucd_rsp_ptr->sr.sense_data,
  			min_t(int, len, SCSI_SENSE_BUFFERSIZE));
  	}
  }

@@ -519,76 +560,128 @@ static void ufshcd_disable_intr(struct ufs_hba *hba, u32 intrs)
  }
 
  /**
+ * ufshcd_prepare_req_desc_hdr() - Fills the requests header
+ * descriptor according to request
+ * @lrbp: pointer to local reference block
+ * @upiu_flags: flags required in the header
+ * @cmd_dir: requests data direction
+ */
+static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
+		u32 *upiu_flags, enum dma_data_direction cmd_dir)
+{
+	struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
+	u32 data_direction;
+	u32 dword_0;
+
+	if (cmd_dir == DMA_FROM_DEVICE) {
+		data_direction = UTP_DEVICE_TO_HOST;
+		*upiu_flags = UPIU_CMD_FLAGS_READ;
+	} else if (cmd_dir == DMA_TO_DEVICE) {
+		data_direction = UTP_HOST_TO_DEVICE;
+		*upiu_flags = UPIU_CMD_FLAGS_WRITE;
+	} else {
+		data_direction = UTP_NO_DATA_TRANSFER;
+		*upiu_flags = UPIU_CMD_FLAGS_NONE;
+	}
+
+	dword_0 = data_direction | (lrbp->command_type
+				<< UPIU_COMMAND_TYPE_OFFSET);
+	if (lrbp->intr_cmd)
+		dword_0 |= UTP_REQ_DESC_INT_CMD;
+
+	/* Transfer request descriptor header fields */
+	req_desc->header.dword_0 = cpu_to_le32(dword_0);
+
+	/*
+	 * assigning invalid value for command status. Controller
+	 * updates OCS on command completion, with the command
+	 * status
+	 */
+	req_desc->header.dword_2 =
+		cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+}
+
+/**
+ * ufshcd_prepare_utp_scsi_cmd_upiu() - fills the utp_transfer_req_desc,
+ * for scsi commands
+ * @lrbp - local reference block pointer
+ * @upiu_flags - flags
+ */
+static
+void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+				UPIU_TRANSACTION_COMMAND, upiu_flags,
+				lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+				UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);
+
+	/* Total EHS length and Data segment length will be zero */
+	ucd_req_ptr->header.dword_2 = 0;
+
+	ucd_req_ptr->sc.exp_data_transfer_len =
+		cpu_to_be32(lrbp->cmd->sdb.length);
+
+	memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd,
+		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
+}
+
+static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	memset(ucd_req_ptr, 0, sizeof(struct utp_upiu_req));
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 =
+		UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_NOP_OUT, 0, 0, lrbp->task_tag);
+}
+
+/**
   * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
+ * @hba - per adapter instance
   * @lrb - pointer to local reference block
   */
-static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
+static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
  {
-	struct utp_transfer_req_desc *req_desc;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
-	u32 data_direction;
  	u32 upiu_flags;
-
-	ucd_cmd_ptr = lrbp->ucd_cmd_ptr;
-	req_desc = lrbp->utr_descriptor_ptr;
+	int ret = 0;
 
  	switch (lrbp->command_type) {
  	case UTP_CMD_TYPE_SCSI:
-		if (lrbp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
-			data_direction = UTP_DEVICE_TO_HOST;
-			upiu_flags = UPIU_CMD_FLAGS_READ;
-		} else if (lrbp->cmd->sc_data_direction == DMA_TO_DEVICE) {
-			data_direction = UTP_HOST_TO_DEVICE;
-			upiu_flags = UPIU_CMD_FLAGS_WRITE;
+		if (likely(lrbp->cmd)) {
+			ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
+					lrbp->cmd->sc_data_direction);
+			ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
  		} else {
-			data_direction = UTP_NO_DATA_TRANSFER;
-			upiu_flags = UPIU_CMD_FLAGS_NONE;
+			ret = -EINVAL;
  		}
-
-		/* Transfer request descriptor header fields */
-		req_desc->header.dword_0 =
-			cpu_to_le32(data_direction | UTP_SCSI_COMMAND);
-
-		/*
-		 * assigning invalid value for command status. Controller
-		 * updates OCS on command completion, with the command
-		 * status
-		 */
-		req_desc->header.dword_2 =
-			cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
-
-		/* command descriptor fields */
-		ucd_cmd_ptr->header.dword_0 =
-			cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_COMMAND,
-						      upiu_flags,
-						      lrbp->lun,
-						      lrbp->task_tag));
-		ucd_cmd_ptr->header.dword_1 =
-			cpu_to_be32(
-				UPIU_HEADER_DWORD(UPIU_COMMAND_SET_TYPE_SCSI,
-						  0,
-						  0,
-						  0));
-
-		/* Total EHS length and Data segment length will be zero */
-		ucd_cmd_ptr->header.dword_2 = 0;
-
-		ucd_cmd_ptr->exp_data_transfer_len =
-			cpu_to_be32(lrbp->cmd->sdb.length);
-
-		memcpy(ucd_cmd_ptr->cdb,
-		       lrbp->cmd->cmnd,
-		       (min_t(unsigned short,
-			      lrbp->cmd->cmd_len,
-			      MAX_CDB_SIZE)));
  		break;
  	case UTP_CMD_TYPE_DEV_MANAGE:
-		/* For query function implementation */
+		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+			ufshcd_prepare_utp_nop_upiu(lrbp);
+		else
+			ret = -EINVAL;
  		break;
  	case UTP_CMD_TYPE_UFS:
  		/* For UFS native command implementation */
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: UFS native command are not supported\n",
+			__func__);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: unknown command type: 0x%x\n",
+				__func__, lrbp->command_type);
  		break;
  	} /* end of switch */
+
+	return ret;
  }
 
  /**

@@ -615,21 +708,37 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
  		goto out;
  	}
 
+	/* acquire the tag to make sure device cmds don't use it */
+	if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) {
+		/*
+		 * Dev manage command in progress, requeue the command.
+		 * Requeuing the command helps in cases where the request *may*
+		 * find different tag instead of waiting for dev manage command
+		 * completion.
+		 */
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
  	lrbp = &hba->lrb[tag];
 
+	WARN_ON(lrbp->cmd);
  	lrbp->cmd = cmd;
  	lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
  	lrbp->sense_buffer = cmd->sense_buffer;
  	lrbp->task_tag = tag;
  	lrbp->lun = cmd->device->lun;
-
+	lrbp->intr_cmd = false;
  	lrbp->command_type = UTP_CMD_TYPE_SCSI;
 
  	/* form UPIU before issuing the command */
-	ufshcd_compose_upiu(lrbp);
+	ufshcd_compose_upiu(hba, lrbp);
  	err = ufshcd_map_sg(lrbp);
-	if (err)
+	if (err) {
+		lrbp->cmd = NULL;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
  		goto out;
+	}
 
  	/* issue command to the controller */
  	spin_lock_irqsave(hba->host->host_lock, flags);

@@ -639,6 +748,198 @@ out:
  	return err;
  }
 
+static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, enum dev_cmd_type cmd_type, int tag)
+{
+	lrbp->cmd = NULL;
+	lrbp->sense_bufflen = 0;
+	lrbp->sense_buffer = NULL;
+	lrbp->task_tag = tag;
+	lrbp->lun = 0; /* device management cmd is not specific to any LUN */
+	lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
+	lrbp->intr_cmd = true; /* No interrupt aggregation */
+	hba->dev_cmd.type = cmd_type;
+
+	return ufshcd_compose_upiu(hba, lrbp);
+}
+
+static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, int max_timeout)
+{
+	int err = 0;
+	unsigned long timeout;
+	unsigned long flags;
+
+	timeout = wait_for_completion_timeout(hba->dev_cmd.complete,
+			msecs_to_jiffies(max_timeout));
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->dev_cmd.complete = NULL;
+	if (timeout)
+		err = ufshcd_get_tr_ocs(lrbp);
+	else
+		err = -ETIMEDOUT;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return err;
+}
+
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c out: · line 806

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +7 -0
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);

4th argument should be (~mask) instead of '0', right?

True, but not really for this implementation. It breaks the check in in wait_for_register -
if ((val & mask) != val)

            dev_err(...);
Quoted 2 lines

Actually, mask value involves the corresponding bit to be cleared. So, 4th argument may be unnecessary.

As I described above, the wait_for_register can also be used to check if the value is set or not. In which case, we need 4th argument.

Quoted 125 lines

drivers/scsi/ufs/ufshcd.c out: · line 808

Quoted 3 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;

Also, checking the result can be involved in ufshcd_wait_for_register.

Quoted 119 lines
drivers/scsi/ufs/ufshcd.c +119 -0
+
+	return err;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int resp;
+	int err = 0;
+
+	resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+	switch (resp) {
+	case UPIU_TRANSACTION_NOP_IN:
+		if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+			err = -EINVAL;
+			dev_err(hba->dev, "%s: unexpected response %x\n",
+					__func__, resp);
+		}
+		break;
+	case UPIU_TRANSACTION_REJECT_UPIU:
+		/* TODO: handle Reject UPIU Response */
+		err = -EPERM;
+		dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+				__func__);
+		break;
+	default:
+		err = -EINVAL;
+		dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+				__func__, resp);
+		break;
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+	int tag;
+	bool ret = false;
+	unsigned long tmp;
+
+	if (!tag_out)
+		goto out;
+
+	do {
+		tmp = ~hba->lrb_in_use;
+		tag = find_last_bit(&tmp, hba->nutrs);
+		if (tag >= hba->nutrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+	*tag_out = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: There is only one available tag for device management commands. Thus
+ * synchronisation is the responsibilty of the user.
+ */
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+		enum dev_cmd_type cmd_type, int timeout)
+{
+	struct ufshcd_lrb *lrbp;
+	int err;
+	int tag;
+	struct completion wait;
+	unsigned long flags;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by SCSI request timeout.
+	 */
+	wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+	init_completion(&wait);
+	lrbp = &hba->lrb[tag];
+	WARN_ON(lrbp->cmd);
+	err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+	if (unlikely(err))
+		goto out_put_tag;
+
+	hba->dev_cmd.complete = &wait;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+

<snip>

Quoted 11 lines

drivers/scsi/ufs/ufshcd.c out: · line 935

Quoted 8 lines
drivers/scsi/ufs/ufshcd.c +8 -0
+	if (err == -ETIMEDOUT) {
+		if (!ufshcd_clear_cmd(hba, tag))
+			err = -EAGAIN;
+	} else if (!err) {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		err = ufshcd_dev_cmd_completion(hba, lrbp);
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}

</snip>
I think sniped part can be involved in ufshcd_wait_for_dev_cmd. How do you think about that?

Yes, it can be moved.

Quoted 25 lines
Quoted 25 lines
drivers/scsi/ufs/ufshcd.c +9 -2
+
+out_put_tag:
+	ufshcd_put_dev_cmd_tag(hba, tag);
+	wake_up(&hba->dev_cmd.tag_wq);
+	return err;
+}
+
  /**
   * ufshcd_memory_alloc - allocate memory for host memory space data structures
   * @hba: per adapter instance

@@ -774,8 +1075,8 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
  				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
 
  		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
-		hba->lrb[i].ucd_cmd_ptr =
-			(struct utp_upiu_cmd *)(cmd_descp + i);
+		hba->lrb[i].ucd_req_ptr =
+			(struct utp_upiu_req *)(cmd_descp + i);
  		hba->lrb[i].ucd_rsp_ptr =
  			(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
  		hba->lrb[i].ucd_prdt_ptr =

@@ -961,6 +1262,38 @@ out:
  }
Quoted 13 lines

drivers/scsi/ufs/ufshcd.c out: · line 1274

Quoted 11 lines
drivers/scsi/ufs/ufshcd.c +10 -0
  /**
+ * ufshcd_validate_dev_connection() - Check device connection status
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_validate_dev_connection(struct ufs_hba *hba)

I think ufshcd_verify_dev_init is close to standard description.

Okay.

Quoted 35 lines
Quoted 35 lines
drivers/scsi/ufs/ufshcd.c +24 -4
+{
+	int err = 0;
+	int retries;
+
+	mutex_lock(&hba->dev_cmd.lock);
+	for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+		err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+					       NOP_OUT_TIMEOUT);
+
+		if (!err || err == -ETIMEDOUT)
+			break;
+
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	if (err)
+		dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+	return err;
+}
+
+/**
   * ufshcd_do_reset - reset the host controller
   * @hba: per adapter instance
   *

@@ -986,13 +1319,20 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
  	for (tag = 0; tag < hba->nutrs; tag++) {
  		if (test_bit(tag, &hba->outstanding_reqs)) {
  			lrbp = &hba->lrb[tag];
-			scsi_dma_unmap(lrbp->cmd);
-			lrbp->cmd->result = DID_RESET << 16;
-			lrbp->cmd->scsi_done(lrbp->cmd);
-			lrbp->cmd = NULL;
+			if (lrbp->cmd) {
+				scsi_dma_unmap(lrbp->cmd);
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c static int ufshcd_do_reset(struct ufs_hba *hba) · line 1328

Quoted 5 lines
drivers/scsi/ufs/ufshcd.c +5 -0
+				lrbp->cmd->result = DID_RESET << 16;
+				lrbp->cmd->scsi_done(lrbp->cmd);
+				lrbp->cmd = NULL;
+				clear_bit_unlock(tag, &hba->lrb_in_use);
+			}

I know above.
But there is no relation to this patch.
Can be it moved to scsi: ufs: Fix device and host reset methods?

Yes, but it is basically to avoid NULL pointer derefernce in case someone picks this patch but not the other one.

Quoted 13 lines
Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +4 -0
  		}
  	}
 
+	/* complete device management command */
+	if (hba->dev_cmd.complete)
+		complete(hba->dev_cmd.complete);
+
  	/* clear outstanding request/task bit maps */
  	hba->outstanding_reqs = 0;
  	hba->outstanding_tasks = 0;

@@ -1199,27 +1539,37 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
Quoted 6 lines

drivers/scsi/ufs/ufshcd.c ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) · line 1542

Quoted 4 lines
drivers/scsi/ufs/ufshcd.c +0 -1
  	switch (ocs) {
  	case OCS_SUCCESS:
-
  		/* check if the returned transfer response is valid */

As replaced with new function, comment isn't valid. Remove or "get the TR response transaction type" seems proper.

Okay.

Quoted 103 lines
Quoted 103 lines
drivers/scsi/ufs/ufshcd.c +47 -27
-		result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
-		if (result) {
+		result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+		switch (result) {
+		case UPIU_TRANSACTION_RESPONSE:
+			/*
+			 * get the response UPIU result to extract
+			 * the SCSI command status
+			 */
+			result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+			/*
+			 * get the result based on SCSI status response
+			 * to notify the SCSI midlayer of the command status
+			 */
+			scsi_status = result & MASK_SCSI_STATUS;
+			result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+			break;
+		case UPIU_TRANSACTION_REJECT_UPIU:
+			/* TODO: handle Reject UPIU Response */
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Reject UPIU not fully implemented\n");
+			break;
+		default:
+			result = DID_ERROR << 16;
  			dev_err(hba->dev,
-				"Invalid response = %x\n", result);
+				"Unexpected request response code = %x\n",
+				result);
  			break;
  		}
-
-		/*
-		 * get the response UPIU result to extract
-		 * the SCSI command status
-		 */
-		result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
-
-		/*
-		 * get the result based on SCSI status response
-		 * to notify the SCSI midlayer of the command status
-		 */
-		scsi_status = result & MASK_SCSI_STATUS;
-		result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
  		break;
  	case OCS_ABORTED:
  		result |= DID_ABORT << 16;

@@ -1259,28 +1609,37 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
   */
  static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
  {
-	struct ufshcd_lrb *lrb;
+	struct ufshcd_lrb *lrbp;
+	struct scsi_cmnd *cmd;
  	unsigned long completed_reqs;
  	u32 tr_doorbell;
  	int result;
  	int index;
+	bool int_aggr_reset = false;
 
-	lrb = hba->lrb;
  	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
  	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
 
  	for (index = 0; index < hba->nutrs; index++) {
  		if (test_bit(index, &completed_reqs)) {
-
-			result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
-
-			if (lrb[index].cmd) {
-				scsi_dma_unmap(lrb[index].cmd);
-				lrb[index].cmd->result = result;
-				lrb[index].cmd->scsi_done(lrb[index].cmd);
-
+			lrbp = &hba->lrb[index];
+			cmd = lrbp->cmd;
+			/* Don't reset counters for interrupt cmd */
+			int_aggr_reset |= !lrbp->intr_cmd;
+
+			if (cmd) {
+				result = ufshcd_transfer_rsp_status(hba, lrbp);
+				scsi_dma_unmap(cmd);
+				cmd->result = result;
  				/* Mark completed command as NULL in LRB */
-				lrb[index].cmd = NULL;
+				lrbp->cmd = NULL;
+				clear_bit_unlock(index, &hba->lrb_in_use);
+				/* Do not touch lrbp after scsi done */
+				cmd->scsi_done(cmd);
+			} else if (lrbp->command_type ==
+					UTP_CMD_TYPE_DEV_MANAGE) {
+				if (hba->dev_cmd.complete)
+					complete(hba->dev_cmd.complete);
  			}
  		} /* end of if */
  	} /* end of for */

@@ -1288,8 +1647,12 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
  	/* clear corresponding bits of completed commands */
  	hba->outstanding_reqs ^= completed_reqs;
Quoted 11 lines

drivers/scsi/ufs/ufshcd.c static void ufshcd_transfer_req_compl(struct ufs_hba *hba) · line 1655

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +5 -1
+	/* we might have free'd some tags above */
+	wake_up(&hba->dev_cmd.tag_wq);
+
  	/* Reset interrupt aggregation counters */
-	ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+	if (int_aggr_reset)
+		ufshcd_config_int_aggr(hba, INT_AGGR_RESET);

Do you assume that interrupt command(device management command) is completed alone? Of course, interrupt command is not counted in aggregation unlike regular command. We need to consider that interrupt command comes along with regular command? If right, ufshcd_config_int_aggr should not be skipped.

True. We are not skipping it. int_aggr_reset will be false only when there is single interrupt command completed.

Check the above part which reads -
for_all_completed_commands() {
int_aggr_reset |= !lrbp->intr_cmd;
}

Even if one of the command in the iteration is not interrupt command (lrbp->intr_cmd is false) then int_aggr_reset is always true.

Quoted 179 lines

Thanks,
Seungwon Jeon

Quoted 174 lines
drivers/scsi/ufs/ufshcd.c +25 -6
  }
 
  /**

@@ -1432,10 +1795,10 @@ ufshcd_issue_tm_cmd(struct ufs_hba *hba,
  	task_req_upiup =
  		(struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
  	task_req_upiup->header.dword_0 =
-		cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
-					      lrbp->lun, lrbp->task_tag));
+		UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
+					      lrbp->lun, lrbp->task_tag);
  	task_req_upiup->header.dword_1 =
-	cpu_to_be32(UPIU_HEADER_DWORD(0, tm_function, 0, 0));
+		UPIU_HEADER_DWORD(0, tm_function, 0, 0);
 
  	task_req_upiup->input_param1 = lrbp->lun;
  	task_req_upiup->input_param1 =

@@ -1502,9 +1865,11 @@ static int ufshcd_device_reset(struct scsi_cmnd *cmd)
  			if (hba->lrb[pos].cmd) {
  				scsi_dma_unmap(hba->lrb[pos].cmd);
  				hba->lrb[pos].cmd->result =
-						DID_ABORT << 16;
+					DID_ABORT << 16;
  				hba->lrb[pos].cmd->scsi_done(cmd);
  				hba->lrb[pos].cmd = NULL;
+				clear_bit_unlock(pos, &hba->lrb_in_use);
+				wake_up(&hba->dev_cmd.tag_wq);
  			}
  		}
  	} /* end of for */

@@ -1572,6 +1937,9 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
  	__clear_bit(tag, &hba->outstanding_reqs);
  	hba->lrb[tag].cmd = NULL;
  	spin_unlock_irqrestore(host->host_lock, flags);
+
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+	wake_up(&hba->dev_cmd.tag_wq);
  out:
  	return err;
  }

@@ -1587,8 +1955,16 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
  	int ret;
 
  	ret = ufshcd_link_startup(hba);
-	if (!ret)
-		scsi_scan_host(hba->host);
+	if (ret)
+		goto out;
+
+	ret = ufshcd_validate_dev_connection(hba);
+	if (ret)
+		goto out;
+
+	scsi_scan_host(hba->host);
+out:
+	return;
  }
 
  static struct scsi_host_template ufshcd_driver_template = {

@@ -1744,6 +2120,12 @@ int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
  	/* Initialize UIC command mutex */
  	mutex_init(&hba->uic_cmd_mutex);
 
+	/* Initialize mutex for device management commands */
+	mutex_init(&hba->dev_cmd.lock);
+
+	/* Initialize device management tag acquire wait queue */
+	init_waitqueue_head(&hba->dev_cmd.tag_wq);
+
  	/* IRQ registration */
  	err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
  	if (err) {
drivers/scsi/ufs/ufshcd.h +27 -3
index 49590ee..c750a90 100644
@@ -68,6 +68,10 @@
  #define UFSHCD "ufshcd"
  #define UFSHCD_DRIVER_VERSION "0.2"
 
+enum dev_cmd_type {
+	DEV_CMD_TYPE_NOP		= 0x0,
+};
+
  /**
   * struct uic_command - UIC command structure
   * @command: UIC command

@@ -91,7 +95,7 @@ struct uic_command {
  /**
   * struct ufshcd_lrb - local reference block
   * @utr_descriptor_ptr: UTRD address of the command
- * @ucd_cmd_ptr: UCD address of the command
+ * @ucd_req_ptr: UCD address of the command
   * @ucd_rsp_ptr: Response UPIU address for this command
   * @ucd_prdt_ptr: PRDT address of the command
   * @cmd: pointer to SCSI command

@@ -101,10 +105,11 @@ struct uic_command {
   * @command_type: SCSI, UFS, Query.
   * @task_tag: Task tag of the command
   * @lun: LUN of the command
+ * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
   */
  struct ufshcd_lrb {
  	struct utp_transfer_req_desc *utr_descriptor_ptr;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
+	struct utp_upiu_req *ucd_req_ptr;
  	struct utp_upiu_rsp *ucd_rsp_ptr;
  	struct ufshcd_sg_entry *ucd_prdt_ptr;
 

@@ -116,8 +121,22 @@ struct ufshcd_lrb {
  	int command_type;
  	int task_tag;
  	unsigned int lun;
+	bool intr_cmd;
  };
 
+/**
+ * struct ufs_dev_cmd - all assosiated fields with device management commands
+ * @type: device management command type - Query, NOP OUT
+ * @lock: lock to allow one command at a time
+ * @complete: internal commands completion
+ * @tag_wq: wait queue until free command slot is available
+ */
+struct ufs_dev_cmd {
+	enum dev_cmd_type type;
+	struct mutex lock;
+	struct completion *complete;
+	wait_queue_head_t tag_wq;
+};
 
  /**
   * struct ufs_hba - per adapter private structure

@@ -131,6 +150,7 @@ struct ufshcd_lrb {
   * @host: Scsi_Host instance of the driver
   * @dev: device handle
   * @lrb: local reference block
+ * @lrb_in_use: lrb in use
   * @outstanding_tasks: Bits representing outstanding task requests
   * @outstanding_reqs: Bits representing outstanding transfer requests
   * @capabilities: UFS Controller Capabilities

@@ -146,6 +166,7 @@ struct ufshcd_lrb {
   * @intr_mask: Interrupt Mask Bits
   * @feh_workq: Work queue for fatal controller error handling
   * @errors: HBA errors
+ * @dev_cmd: ufs device management command information
   */
  struct ufs_hba {
  	void __iomem *mmio_base;

@@ -164,6 +185,7 @@ struct ufs_hba {
  	struct device *dev;
 
  	struct ufshcd_lrb *lrb;
+	unsigned long lrb_in_use;
 
  	unsigned long outstanding_tasks;
  	unsigned long outstanding_reqs;

@@ -188,6 +210,9 @@ struct ufs_hba {
 
  	/* HBA Errors */
  	u32 errors;
+
+	/* Device management request data */
+	struct ufs_dev_cmd dev_cmd;
  };
 
  #define ufshcd_writel(hba, val, reg)	\
--

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Signature · 2 lines
Regards,
Sujit
#5 lore raw

RE: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

Quoted 170 lines · Sujit Reddy Thumma
Quoted 142 lines · Seungwon Jeon
Quoted 141 lines · Sujit Reddy Thumma

As part of device initialization sequence, sending NOP OUT UPIU and waiting for NOP IN UPIU response is mandatory. This confirms that the device UFS Transport (UTP) layer is functional and the host can configure the device with further commands. Add support for sending NOP OUT UPIU to check the device connection path and test whether the UTP layer on the device side is functional during initialization.

A tag is acquired from the SCSI tag map space in order to send the device management command. When the tag is acquired by internal command the scsi command is rejected with host busy flag in order to requeue the request. To avoid frequent collisions between internal commands and scsi commands the device management command tag is allocated in the opposite direction w.r.t block layer tag allocation.

Signed-off-by Sujit Reddy Thumma <[email protected]>
Signed-off-by Dolev Raviv <[email protected]>
---
  drivers/scsi/ufs/ufs.h    |   43 +++-
  drivers/scsi/ufs/ufshcd.c |  596 +++++++++++++++++++++++++++++++++++++--------
  drivers/scsi/ufs/ufshcd.h |   29 ++-
  3 files changed, 552 insertions(+), 116 deletions(-)
drivers/scsi/ufs/ufs.h +36 -7
index 139bc06..14c0a4e 100644
@@ -36,10 +36,16 @@
  #ifndef _UFS_H
  #define _UFS_H
 
+#include <linux/mutex.h>
+#include <linux/types.h>
+
  #define MAX_CDB_SIZE	16
+#define GENERAL_UPIU_REQUEST_SIZE 32
+#define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
+					(GENERAL_UPIU_REQUEST_SIZE))
 
  #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
-			((byte3 << 24) | (byte2 << 16) |\
+			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
  			 (byte1 << 8) | (byte0))
 
  /*

@@ -73,6 +79,7 @@ enum {
  	UPIU_TRANSACTION_TASK_RSP	= 0x24,
  	UPIU_TRANSACTION_READY_XFER	= 0x31,
  	UPIU_TRANSACTION_QUERY_RSP	= 0x36,
+	UPIU_TRANSACTION_REJECT_UPIU	= 0x3F,
  };
 
  /* UPIU Read/Write flags */

@@ -110,6 +117,12 @@ enum {
  	UPIU_COMMAND_SET_TYPE_QUERY	= 0x2,
  };
 
+/* UTP Transfer Request Command Offset */
+#define UPIU_COMMAND_TYPE_OFFSET	28
+
+/* Offset of the response code in the UPIU header */
+#define UPIU_RSP_CODE_OFFSET		8
+
  enum {
  	MASK_SCSI_STATUS	= 0xFF,
  	MASK_TASK_RESPONSE	= 0xFF00,

@@ -138,26 +151,32 @@ struct utp_upiu_header {
 
  /**
   * struct utp_upiu_cmd - Command UPIU structure
- * @header: UPIU header structure DW-0 to DW-2
   * @data_transfer_len: Data Transfer Length DW-3
   * @cdb: Command Descriptor Block CDB DW-4 to DW-7
   */
  struct utp_upiu_cmd {
-	struct utp_upiu_header header;
  	u32 exp_data_transfer_len;
  	u8 cdb[MAX_CDB_SIZE];
  };
 
  /**
- * struct utp_upiu_rsp - Response UPIU structure
- * @header: UPIU header DW-0 to DW-2
+ * struct utp_upiu_req - general upiu request structure
+ * @header:UPIU header structure DW-0 to DW-2
+ * @sc: fields structure for scsi command DW-3 to DW-7
+ */
+struct utp_upiu_req {
+	struct utp_upiu_header header;
+	struct utp_upiu_cmd sc;
+};
+
+/**
+ * struct utp_cmd_rsp - Response UPIU structure
   * @residual_transfer_count: Residual transfer count DW-3
   * @reserved: Reserved double words DW-4 to DW-7
   * @sense_data_len: Sense data length DW-8 U16
   * @sense_data: Sense data field DW-8 to DW-12
   */
-struct utp_upiu_rsp {
-	struct utp_upiu_header header;
+struct utp_cmd_rsp {
  	u32 residual_transfer_count;
  	u32 reserved[4];
  	u16 sense_data_len;

@@ -165,6 +184,16 @@ struct utp_upiu_rsp {
  };
 
  /**
+ * struct utp_upiu_rsp - general upiu response structure
+ * @header: UPIU header structure DW-0 to DW-2
+ * @sr: fields structure for scsi command DW-3 to DW-12
+ */
+struct utp_upiu_rsp {
+	struct utp_upiu_header header;
+	struct utp_cmd_rsp sr;
+};
+
+/**
   * struct utp_upiu_task_req - Task request UPIU structure
   * @header - UPIU header structure DW0 to DW-2
   * @input_param1: Input parameter 1 DW-3
drivers/scsi/ufs/ufshcd.c +5 -0
index b743bd6..3f482b6 100644
@@ -43,6 +43,11 @@
  /* UIC command timeout, unit: ms */
  #define UIC_CMD_TIMEOUT	500
 
+/* NOP OUT retries waiting for NOP IN response */
+#define NOP_OUT_RETRIES    10
+/* Timeout after 30 msecs if NOP OUT hangs without response */
+#define NOP_OUT_TIMEOUT    30 /* msecs */
+
  enum {
  	UFSHCD_MAX_CHANNEL	= 0,
  	UFSHCD_MAX_ID		= 1,

@@ -71,6 +76,47 @@ enum {
  	INT_AGGR_CONFIG,
  };
Quoted 15 lines

drivers/scsi/ufs/ufshcd.c enum { · line 91

Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +13 -0
+/*
+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)

I feel like this function's role is to wait for clearing register (specially, doorbells). If you really don't intend to apply other all register, I think it would better to change the

function name.

Quoted 1 line

ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?

Although, this API is introduced in this patch and used only for clearing the doorbell, I have intentionally made it generic to avoid duplication of wait condition code in future (not just clearing but also for setting a bit). For example, when we write to HCE.ENABLE we wait for it turn to 1.

Quoted 2 lines

And if you like it, it could be more simple like below

Quoted 8 lines
Quoted 5 lines

static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us, unsigned int timeout_ms)

{
         unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);

Jiffies on 100Hz systems have minimum granularity of 10ms. So we really wait for more 10ms even though the timeout_ms < 10ms.

Yes. Real timeout depends on system.
But normally actual wait will be maintained until 'ufshcd_readl' is done.
Timeout is valid for failure case. If we don't need to apply a strict timeout value, it's not bad.

Quoted 10 lines
Quoted 9 lines
         /* wakeup within 50us of expiry */
         const unsigned int expiry = 50;

         while (ufshcd_readl(hba, reg) & mask) {
                 usleep_range(interval_us, interval_us + expiry);
                 if (time_after(jiffies, timeout)) {
                         if (ufshcd_readl(hba, reg) & mask)
                                 return false;
Quoted 3 lines

I really want the caller to decide on what to do after the timeout. This helps in error handling cases where we try to clear off the entire door-bell register but only a few of the bits are cleared after timeout.

I don't know what we can do with the report of the partial success on clearing bit. It's just failure case. Isn't enough with false/true?

Quoted 358 lines
Quoted 349 lines
                         else
                                 return true;
                 }
         }

         return true;
}
Quoted 341 lines
drivers/scsi/ufs/ufshcd.c +206 -66
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+
  /**
   * ufshcd_get_intr_mask - Get the interrupt bit mask
   * @hba - Pointer to adapter instance

@@ -191,18 +237,13 @@ static inline int ufshcd_get_uic_cmd_result(struct ufs_hba *hba)
  }
 
  /**
- * ufshcd_is_valid_req_rsp - checks if controller TR response is valid
+ * ufshcd_get_req_rsp - returns the TR response transaction type
   * @ucd_rsp_ptr: pointer to response UPIU
- *
- * This function checks the response UPIU for valid transaction type in
- * response field
- * Returns 0 on success, non-zero on failure
   */
  static inline int
-ufshcd_is_valid_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
+ufshcd_get_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
  {
-	return ((be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24) ==
-		 UPIU_TRANSACTION_RESPONSE) ? 0 : DID_ERROR << 16;
+	return be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24;
  }
 
  /**

@@ -299,9 +340,9 @@ static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
  {
  	int len;
  	if (lrbp->sense_buffer) {
-		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
+		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
  		memcpy(lrbp->sense_buffer,
-			lrbp->ucd_rsp_ptr->sense_data,
+			lrbp->ucd_rsp_ptr->sr.sense_data,
  			min_t(int, len, SCSI_SENSE_BUFFERSIZE));
  	}
  }

@@ -519,76 +560,128 @@ static void ufshcd_disable_intr(struct ufs_hba *hba, u32 intrs)
  }
 
  /**
+ * ufshcd_prepare_req_desc_hdr() - Fills the requests header
+ * descriptor according to request
+ * @lrbp: pointer to local reference block
+ * @upiu_flags: flags required in the header
+ * @cmd_dir: requests data direction
+ */
+static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
+		u32 *upiu_flags, enum dma_data_direction cmd_dir)
+{
+	struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
+	u32 data_direction;
+	u32 dword_0;
+
+	if (cmd_dir == DMA_FROM_DEVICE) {
+		data_direction = UTP_DEVICE_TO_HOST;
+		*upiu_flags = UPIU_CMD_FLAGS_READ;
+	} else if (cmd_dir == DMA_TO_DEVICE) {
+		data_direction = UTP_HOST_TO_DEVICE;
+		*upiu_flags = UPIU_CMD_FLAGS_WRITE;
+	} else {
+		data_direction = UTP_NO_DATA_TRANSFER;
+		*upiu_flags = UPIU_CMD_FLAGS_NONE;
+	}
+
+	dword_0 = data_direction | (lrbp->command_type
+				<< UPIU_COMMAND_TYPE_OFFSET);
+	if (lrbp->intr_cmd)
+		dword_0 |= UTP_REQ_DESC_INT_CMD;
+
+	/* Transfer request descriptor header fields */
+	req_desc->header.dword_0 = cpu_to_le32(dword_0);
+
+	/*
+	 * assigning invalid value for command status. Controller
+	 * updates OCS on command completion, with the command
+	 * status
+	 */
+	req_desc->header.dword_2 =
+		cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
+}
+
+/**
+ * ufshcd_prepare_utp_scsi_cmd_upiu() - fills the utp_transfer_req_desc,
+ * for scsi commands
+ * @lrbp - local reference block pointer
+ * @upiu_flags - flags
+ */
+static
+void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+				UPIU_TRANSACTION_COMMAND, upiu_flags,
+				lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+				UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);
+
+	/* Total EHS length and Data segment length will be zero */
+	ucd_req_ptr->header.dword_2 = 0;
+
+	ucd_req_ptr->sc.exp_data_transfer_len =
+		cpu_to_be32(lrbp->cmd->sdb.length);
+
+	memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd,
+		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
+}
+
+static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+
+	memset(ucd_req_ptr, 0, sizeof(struct utp_upiu_req));
+
+	/* command descriptor fields */
+	ucd_req_ptr->header.dword_0 =
+		UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_NOP_OUT, 0, 0, lrbp->task_tag);
+}
+
+/**
   * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
+ * @hba - per adapter instance
   * @lrb - pointer to local reference block
   */
-static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
+static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
  {
-	struct utp_transfer_req_desc *req_desc;
-	struct utp_upiu_cmd *ucd_cmd_ptr;
-	u32 data_direction;
  	u32 upiu_flags;
-
-	ucd_cmd_ptr = lrbp->ucd_cmd_ptr;
-	req_desc = lrbp->utr_descriptor_ptr;
+	int ret = 0;
 
  	switch (lrbp->command_type) {
  	case UTP_CMD_TYPE_SCSI:
-		if (lrbp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
-			data_direction = UTP_DEVICE_TO_HOST;
-			upiu_flags = UPIU_CMD_FLAGS_READ;
-		} else if (lrbp->cmd->sc_data_direction == DMA_TO_DEVICE) {
-			data_direction = UTP_HOST_TO_DEVICE;
-			upiu_flags = UPIU_CMD_FLAGS_WRITE;
+		if (likely(lrbp->cmd)) {
+			ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
+					lrbp->cmd->sc_data_direction);
+			ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
  		} else {
-			data_direction = UTP_NO_DATA_TRANSFER;
-			upiu_flags = UPIU_CMD_FLAGS_NONE;
+			ret = -EINVAL;
  		}
-
-		/* Transfer request descriptor header fields */
-		req_desc->header.dword_0 =
-			cpu_to_le32(data_direction | UTP_SCSI_COMMAND);
-
-		/*
-		 * assigning invalid value for command status. Controller
-		 * updates OCS on command completion, with the command
-		 * status
-		 */
-		req_desc->header.dword_2 =
-			cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
-
-		/* command descriptor fields */
-		ucd_cmd_ptr->header.dword_0 =
-			cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_COMMAND,
-						      upiu_flags,
-						      lrbp->lun,
-						      lrbp->task_tag));
-		ucd_cmd_ptr->header.dword_1 =
-			cpu_to_be32(
-				UPIU_HEADER_DWORD(UPIU_COMMAND_SET_TYPE_SCSI,
-						  0,
-						  0,
-						  0));
-
-		/* Total EHS length and Data segment length will be zero */
-		ucd_cmd_ptr->header.dword_2 = 0;
-
-		ucd_cmd_ptr->exp_data_transfer_len =
-			cpu_to_be32(lrbp->cmd->sdb.length);
-
-		memcpy(ucd_cmd_ptr->cdb,
-		       lrbp->cmd->cmnd,
-		       (min_t(unsigned short,
-			      lrbp->cmd->cmd_len,
-			      MAX_CDB_SIZE)));
  		break;
  	case UTP_CMD_TYPE_DEV_MANAGE:
-		/* For query function implementation */
+		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+			ufshcd_prepare_utp_nop_upiu(lrbp);
+		else
+			ret = -EINVAL;
  		break;
  	case UTP_CMD_TYPE_UFS:
  		/* For UFS native command implementation */
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: UFS native command are not supported\n",
+			__func__);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		dev_err(hba->dev, "%s: unknown command type: 0x%x\n",
+				__func__, lrbp->command_type);
  		break;
  	} /* end of switch */
+
+	return ret;
  }
 
  /**

@@ -615,21 +708,37 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
  		goto out;
  	}
 
+	/* acquire the tag to make sure device cmds don't use it */
+	if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) {
+		/*
+		 * Dev manage command in progress, requeue the command.
+		 * Requeuing the command helps in cases where the request *may*
+		 * find different tag instead of waiting for dev manage command
+		 * completion.
+		 */
+		err = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
  	lrbp = &hba->lrb[tag];
 
+	WARN_ON(lrbp->cmd);
  	lrbp->cmd = cmd;
  	lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
  	lrbp->sense_buffer = cmd->sense_buffer;
  	lrbp->task_tag = tag;
  	lrbp->lun = cmd->device->lun;
-
+	lrbp->intr_cmd = false;
  	lrbp->command_type = UTP_CMD_TYPE_SCSI;
 
  	/* form UPIU before issuing the command */
-	ufshcd_compose_upiu(lrbp);
+	ufshcd_compose_upiu(hba, lrbp);
  	err = ufshcd_map_sg(lrbp);
-	if (err)
+	if (err) {
+		lrbp->cmd = NULL;
+		clear_bit_unlock(tag, &hba->lrb_in_use);
  		goto out;
+	}
 
  	/* issue command to the controller */
  	spin_lock_irqsave(hba->host->host_lock, flags);

@@ -639,6 +748,198 @@ out:
  	return err;
  }
 
+static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, enum dev_cmd_type cmd_type, int tag)
+{
+	lrbp->cmd = NULL;
+	lrbp->sense_bufflen = 0;
+	lrbp->sense_buffer = NULL;
+	lrbp->task_tag = tag;
+	lrbp->lun = 0; /* device management cmd is not specific to any LUN */
+	lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
+	lrbp->intr_cmd = true; /* No interrupt aggregation */
+	hba->dev_cmd.type = cmd_type;
+
+	return ufshcd_compose_upiu(hba, lrbp);
+}
+
+static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
+		struct ufshcd_lrb *lrbp, int max_timeout)
+{
+	int err = 0;
+	unsigned long timeout;
+	unsigned long flags;
+
+	timeout = wait_for_completion_timeout(hba->dev_cmd.complete,
+			msecs_to_jiffies(max_timeout));
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	hba->dev_cmd.complete = NULL;
+	if (timeout)
+		err = ufshcd_get_tr_ocs(lrbp);
+	else
+		err = -ETIMEDOUT;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	return err;
+}
+
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c out: · line 806

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +7 -0
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);

4th argument should be (~mask) instead of '0', right?

Quoted 4 lines

True, but not really for this implementation. It breaks the check in in wait_for_register -
if ((val & mask) != val)

            dev_err(...);

Hmm, it seems complicated to use.
Ok. Is right the following about val as 4th argument?
- clear: val should be '0' regardless corresponding bit.
- set: val should be same with mask.
If the related comment is added, it will be helpful.

Quoted 11 lines
Quoted 3 lines

Actually, mask value involves the corresponding bit to be cleared. So, 4th argument may be unnecessary.

As I described above, the wait_for_register can also be used to check if the value is set or not. In which case, we need 4th argument.

Quoted 4 lines

drivers/scsi/ufs/ufshcd.c out: · line 808

Quoted 3 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;

Also, checking the result can be involved in ufshcd_wait_for_register.

Any comment?

Quoted 363 lines
Quoted 121 lines
Quoted 120 lines
drivers/scsi/ufs/ufshcd.c +119 -0
+
+	return err;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int resp;
+	int err = 0;
+
+	resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+	switch (resp) {
+	case UPIU_TRANSACTION_NOP_IN:
+		if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+			err = -EINVAL;
+			dev_err(hba->dev, "%s: unexpected response %x\n",
+					__func__, resp);
+		}
+		break;
+	case UPIU_TRANSACTION_REJECT_UPIU:
+		/* TODO: handle Reject UPIU Response */
+		err = -EPERM;
+		dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+				__func__);
+		break;
+	default:
+		err = -EINVAL;
+		dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+				__func__, resp);
+		break;
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+	int tag;
+	bool ret = false;
+	unsigned long tmp;
+
+	if (!tag_out)
+		goto out;
+
+	do {
+		tmp = ~hba->lrb_in_use;
+		tag = find_last_bit(&tmp, hba->nutrs);
+		if (tag >= hba->nutrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+	*tag_out = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: There is only one available tag for device management commands. Thus
+ * synchronisation is the responsibilty of the user.
+ */
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+		enum dev_cmd_type cmd_type, int timeout)
+{
+	struct ufshcd_lrb *lrbp;
+	int err;
+	int tag;
+	struct completion wait;
+	unsigned long flags;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by SCSI request timeout.
+	 */
+	wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+	init_completion(&wait);
+	lrbp = &hba->lrb[tag];
+	WARN_ON(lrbp->cmd);
+	err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+	if (unlikely(err))
+		goto out_put_tag;
+
+	hba->dev_cmd.complete = &wait;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+

<snip>

Quoted 11 lines

drivers/scsi/ufs/ufshcd.c out: · line 935

Quoted 8 lines
drivers/scsi/ufs/ufshcd.c +8 -0
+	if (err == -ETIMEDOUT) {
+		if (!ufshcd_clear_cmd(hba, tag))
+			err = -EAGAIN;
+	} else if (!err) {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		err = ufshcd_dev_cmd_completion(hba, lrbp);
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}

</snip>
I think sniped part can be involved in ufshcd_wait_for_dev_cmd. How do you think about that?

Yes, it can be moved.

Quoted 25 lines
Quoted 25 lines
drivers/scsi/ufs/ufshcd.c +9 -2
+
+out_put_tag:
+	ufshcd_put_dev_cmd_tag(hba, tag);
+	wake_up(&hba->dev_cmd.tag_wq);
+	return err;
+}
+
  /**
   * ufshcd_memory_alloc - allocate memory for host memory space data structures
   * @hba: per adapter instance

@@ -774,8 +1075,8 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
  				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
 
  		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
-		hba->lrb[i].ucd_cmd_ptr =
-			(struct utp_upiu_cmd *)(cmd_descp + i);
+		hba->lrb[i].ucd_req_ptr =
+			(struct utp_upiu_req *)(cmd_descp + i);
  		hba->lrb[i].ucd_rsp_ptr =
  			(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
  		hba->lrb[i].ucd_prdt_ptr =

@@ -961,6 +1262,38 @@ out:
  }
Quoted 13 lines

drivers/scsi/ufs/ufshcd.c out: · line 1274

Quoted 11 lines
drivers/scsi/ufs/ufshcd.c +10 -0
  /**
+ * ufshcd_validate_dev_connection() - Check device connection status
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_validate_dev_connection(struct ufs_hba *hba)

I think ufshcd_verify_dev_init is close to standard description.

Okay.

Quoted 35 lines
Quoted 35 lines
drivers/scsi/ufs/ufshcd.c +24 -4
+{
+	int err = 0;
+	int retries;
+
+	mutex_lock(&hba->dev_cmd.lock);
+	for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+		err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+					       NOP_OUT_TIMEOUT);
+
+		if (!err || err == -ETIMEDOUT)
+			break;
+
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	if (err)
+		dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+	return err;
+}
+
+/**
   * ufshcd_do_reset - reset the host controller
   * @hba: per adapter instance
   *

@@ -986,13 +1319,20 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
  	for (tag = 0; tag < hba->nutrs; tag++) {
  		if (test_bit(tag, &hba->outstanding_reqs)) {
  			lrbp = &hba->lrb[tag];
-			scsi_dma_unmap(lrbp->cmd);
-			lrbp->cmd->result = DID_RESET << 16;
-			lrbp->cmd->scsi_done(lrbp->cmd);
-			lrbp->cmd = NULL;
+			if (lrbp->cmd) {
+				scsi_dma_unmap(lrbp->cmd);
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c static int ufshcd_do_reset(struct ufs_hba *hba) · line 1328

Quoted 5 lines
drivers/scsi/ufs/ufshcd.c +5 -0
+				lrbp->cmd->result = DID_RESET << 16;
+				lrbp->cmd->scsi_done(lrbp->cmd);
+				lrbp->cmd = NULL;
+				clear_bit_unlock(tag, &hba->lrb_in_use);
+			}

I know above.
But there is no relation to this patch.
Can be it moved to scsi: ufs: Fix device and host reset methods?

Yes, but it is basically to avoid NULL pointer derefernce in case someone picks this patch but not the other one.

Quoted 13 lines
Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +4 -0
  		}
  	}
 
+	/* complete device management command */
+	if (hba->dev_cmd.complete)
+		complete(hba->dev_cmd.complete);
+
  	/* clear outstanding request/task bit maps */
  	hba->outstanding_reqs = 0;
  	hba->outstanding_tasks = 0;

@@ -1199,27 +1539,37 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
Quoted 6 lines

drivers/scsi/ufs/ufshcd.c ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) · line 1542

Quoted 4 lines
drivers/scsi/ufs/ufshcd.c +0 -1
  	switch (ocs) {
  	case OCS_SUCCESS:
-
  		/* check if the returned transfer response is valid */

As replaced with new function, comment isn't valid. Remove or "get the TR response transaction type" seems proper.

Okay.

Quoted 103 lines
Quoted 103 lines
drivers/scsi/ufs/ufshcd.c +47 -27
-		result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
-		if (result) {
+		result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+		switch (result) {
+		case UPIU_TRANSACTION_RESPONSE:
+			/*
+			 * get the response UPIU result to extract
+			 * the SCSI command status
+			 */
+			result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+			/*
+			 * get the result based on SCSI status response
+			 * to notify the SCSI midlayer of the command status
+			 */
+			scsi_status = result & MASK_SCSI_STATUS;
+			result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+			break;
+		case UPIU_TRANSACTION_REJECT_UPIU:
+			/* TODO: handle Reject UPIU Response */
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Reject UPIU not fully implemented\n");
+			break;
+		default:
+			result = DID_ERROR << 16;
  			dev_err(hba->dev,
-				"Invalid response = %x\n", result);
+				"Unexpected request response code = %x\n",
+				result);
  			break;
  		}
-
-		/*
-		 * get the response UPIU result to extract
-		 * the SCSI command status
-		 */
-		result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
-
-		/*
-		 * get the result based on SCSI status response
-		 * to notify the SCSI midlayer of the command status
-		 */
-		scsi_status = result & MASK_SCSI_STATUS;
-		result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
  		break;
  	case OCS_ABORTED:
  		result |= DID_ABORT << 16;

@@ -1259,28 +1609,37 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
   */
  static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
  {
-	struct ufshcd_lrb *lrb;
+	struct ufshcd_lrb *lrbp;
+	struct scsi_cmnd *cmd;
  	unsigned long completed_reqs;
  	u32 tr_doorbell;
  	int result;
  	int index;
+	bool int_aggr_reset = false;
 
-	lrb = hba->lrb;
  	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
  	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
 
  	for (index = 0; index < hba->nutrs; index++) {
  		if (test_bit(index, &completed_reqs)) {
-
-			result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
-
-			if (lrb[index].cmd) {
-				scsi_dma_unmap(lrb[index].cmd);
-				lrb[index].cmd->result = result;
-				lrb[index].cmd->scsi_done(lrb[index].cmd);
-
+			lrbp = &hba->lrb[index];
+			cmd = lrbp->cmd;
+			/* Don't reset counters for interrupt cmd */
+			int_aggr_reset |= !lrbp->intr_cmd;
+
+			if (cmd) {
+				result = ufshcd_transfer_rsp_status(hba, lrbp);
+				scsi_dma_unmap(cmd);
+				cmd->result = result;
  				/* Mark completed command as NULL in LRB */
-				lrb[index].cmd = NULL;
+				lrbp->cmd = NULL;
+				clear_bit_unlock(index, &hba->lrb_in_use);
+				/* Do not touch lrbp after scsi done */
+				cmd->scsi_done(cmd);
+			} else if (lrbp->command_type ==
+					UTP_CMD_TYPE_DEV_MANAGE) {
+				if (hba->dev_cmd.complete)
+					complete(hba->dev_cmd.complete);
  			}
  		} /* end of if */
  	} /* end of for */

@@ -1288,8 +1647,12 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
  	/* clear corresponding bits of completed commands */
  	hba->outstanding_reqs ^= completed_reqs;
Quoted 11 lines

drivers/scsi/ufs/ufshcd.c static void ufshcd_transfer_req_compl(struct ufs_hba *hba) · line 1655

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +5 -1
+	/* we might have free'd some tags above */
+	wake_up(&hba->dev_cmd.tag_wq);
+
  	/* Reset interrupt aggregation counters */
-	ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+	if (int_aggr_reset)
+		ufshcd_config_int_aggr(hba, INT_AGGR_RESET);

Do you assume that interrupt command(device management command) is completed alone? Of course, interrupt command is not counted in aggregation unlike regular command. We need to consider that interrupt command comes along with regular command? If right, ufshcd_config_int_aggr should not be skipped.

True. We are not skipping it. int_aggr_reset will be false only when there is single interrupt command completed.

Quoted 7 lines

Check the above part which reads -
for_all_completed_commands() {
int_aggr_reset |= !lrbp->intr_cmd;
}

Even if one of the command in the iteration is not interrupt command (lrbp->intr_cmd is false) then int_aggr_reset is always true.

Clear!
But I confused it with your comment line. (/* Don't reset counters for interrupt cmd */) How about changing like below?
'Don't skip to reset counters if a regular command is present'

Thanks,
Seungwon Jeon

author
#6 lore raw

Re: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

Quoted 34 lines
Quoted 34 lines
Quoted 16 lines
Quoted 12 lines

+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs
+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */

drivers/scsi/ufs/ufshcd.c enum { · line 91

Quoted 2 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)

I feel like this function's role is to wait for clearing register (specially, doorbells). If you really don't intend to apply other all register, I think it would better to change the

function name.

Quoted 1 line

ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?

Although, this API is introduced in this patch and used only for clearing the doorbell, I have intentionally made it generic to avoid duplication of wait condition code in future (not just clearing but also for setting a bit). For example, when we write to HCE.ENABLE we wait for it turn to 1.

Quoted 7 lines

And if you like it, it could be more simple like below

static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us, unsigned int timeout_ms)

{
          unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
Quoted 5 lines
Quoted 2 lines

Jiffies on 100Hz systems have minimum granularity of 10ms. So we really wait for more 10ms even though the timeout_ms < 10ms.

Yes. Real timeout depends on system.
But normally actual wait will be maintained until 'ufshcd_readl' is done.
Timeout is valid for failure case. If we don't need to apply a strict timeout value, it's not bad.

Hmm.. make sense. Will take care in the next patchset.

Quoted 11 lines
Quoted 11 lines
Quoted 10 lines

          /* wakeup within 50us of expiry */
          const unsigned int expiry = 50;

          while (ufshcd_readl(hba, reg) & mask) {
                  usleep_range(interval_us, interval_us + expiry);
                  if (time_after(jiffies, timeout)) {
                          if (ufshcd_readl(hba, reg) & mask)
                                  return false;
Quoted 5 lines
Quoted 3 lines

I really want the caller to decide on what to do after the timeout. This helps in error handling cases where we try to clear off the entire door-bell register but only a few of the bits are cleared after timeout.

I don't know what we can do with the report of the partial success on clearing bit. It's just failure case. Isn't enough with false/true?

The point is, if a bit can't be cleared it can be regarded as a permanent failure (only for that request), otherwise, it can be retried with the same tag value.

Quoted 37 lines
Quoted 37 lines
Quoted 37 lines

                          else
                                  return true;
                  }
          }

          return true;
}
Quoted 28 lines
drivers/scsi/ufs/ufshcd.c +28 -0
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+

..

Quoted 26 lines
Quoted 22 lines
Quoted 13 lines
Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +13 -0
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c out: · line 806

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +7 -0
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);

4th argument should be (~mask) instead of '0', right?

Quoted 4 lines

True, but not really for this implementation. It breaks the check in in wait_for_register -
if ((val & mask) != val)

             dev_err(...);
Quoted 5 lines

Hmm, it seems complicated to use.
Ok. Is right the following about val as 4th argument?
- clear: val should be '0' regardless corresponding bit.
- set: val should be same with mask.
If the related comment is added, it will be helpful.

Thinking again it looks like it is complicated. How about changing the check to -

val = val & mask; /* ignore the bits we don't intend to wait on */ while (ufshcd_readl() & mask != val) {
sleep
}

Usage will be ~mask for clearing the bits, mask for setting the bits in the fourth argument.

Quoted 5 lines
Quoted 5 lines
Quoted 4 lines

Actually, mask value involves the corresponding bit to be cleared. So, 4th argument may be unnecessary.

Quoted 8 lines
Quoted 7 lines

As I described above, the wait_for_register can also be used to check if the value is set or not. In which case, we need 4th argument.

Quoted 4 lines

drivers/scsi/ufs/ufshcd.c out: · line 808

Quoted 3 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;

Also, checking the result can be involved in ufshcd_wait_for_register.

Any comment?

Sorry I missed this. But the point was the same. To make wait_for_register() just to wait a definite time and not return any error condition when the bits don't turn as expected.

Quoted 369 lines
Quoted 369 lines
Quoted 122 lines
Quoted 121 lines
drivers/scsi/ufs/ufshcd.c +119 -0
+
+	return err;
+}
+
+/**
+ * ufshcd_dev_cmd_completion() - handles device management command responses
+ * @hba: per adapter instance
+ * @lrbp: pointer to local reference block
+ */
+static int
+ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	int resp;
+	int err = 0;
+
+	resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+	switch (resp) {
+	case UPIU_TRANSACTION_NOP_IN:
+		if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
+			err = -EINVAL;
+			dev_err(hba->dev, "%s: unexpected response %x\n",
+					__func__, resp);
+		}
+		break;
+	case UPIU_TRANSACTION_REJECT_UPIU:
+		/* TODO: handle Reject UPIU Response */
+		err = -EPERM;
+		dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
+				__func__);
+		break;
+	default:
+		err = -EINVAL;
+		dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
+				__func__, resp);
+		break;
+	}
+
+	return err;
+}
+
+/**
+ * ufshcd_get_dev_cmd_tag - Get device management command tag
+ * @hba: per-adapter instance
+ * @tag: pointer to variable with available slot value
+ *
+ * Get a free slot and lock it until device management command
+ * completes.
+ *
+ * Returns false if free slot is unavailable for locking, else
+ * return true with tag value in @tag.
+ */
+static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
+{
+	int tag;
+	bool ret = false;
+	unsigned long tmp;
+
+	if (!tag_out)
+		goto out;
+
+	do {
+		tmp = ~hba->lrb_in_use;
+		tag = find_last_bit(&tmp, hba->nutrs);
+		if (tag >= hba->nutrs)
+			goto out;
+	} while (test_and_set_bit_lock(tag, &hba->lrb_in_use));
+
+	*tag_out = tag;
+	ret = true;
+out:
+	return ret;
+}
+
+static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
+{
+	clear_bit_unlock(tag, &hba->lrb_in_use);
+}
+
+/**
+ * ufshcd_exec_dev_cmd - API for sending device management requests
+ * @hba - UFS hba
+ * @cmd_type - specifies the type (NOP, Query...)
+ * @timeout - time in seconds
+ *
+ * NOTE: There is only one available tag for device management commands. Thus
+ * synchronisation is the responsibilty of the user.
+ */
+static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
+		enum dev_cmd_type cmd_type, int timeout)
+{
+	struct ufshcd_lrb *lrbp;
+	int err;
+	int tag;
+	struct completion wait;
+	unsigned long flags;
+
+	/*
+	 * Get free slot, sleep if slots are unavailable.
+	 * Even though we use wait_event() which sleeps indefinitely,
+	 * the maximum wait time is bounded by SCSI request timeout.
+	 */
+	wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));
+
+	init_completion(&wait);
+	lrbp = &hba->lrb[tag];
+	WARN_ON(lrbp->cmd);
+	err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
+	if (unlikely(err))
+		goto out_put_tag;
+
+	hba->dev_cmd.complete = &wait;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_send_command(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);
+

<snip>

Quoted 11 lines

drivers/scsi/ufs/ufshcd.c out: · line 935

Quoted 8 lines
drivers/scsi/ufs/ufshcd.c +8 -0
+	if (err == -ETIMEDOUT) {
+		if (!ufshcd_clear_cmd(hba, tag))
+			err = -EAGAIN;
+	} else if (!err) {
+		spin_lock_irqsave(hba->host->host_lock, flags);
+		err = ufshcd_dev_cmd_completion(hba, lrbp);
+		spin_unlock_irqrestore(hba->host->host_lock, flags);
+	}

</snip>
I think sniped part can be involved in ufshcd_wait_for_dev_cmd. How do you think about that?

Yes, it can be moved.

Quoted 25 lines
Quoted 25 lines
drivers/scsi/ufs/ufshcd.c +9 -2
+
+out_put_tag:
+	ufshcd_put_dev_cmd_tag(hba, tag);
+	wake_up(&hba->dev_cmd.tag_wq);
+	return err;
+}
+
   /**
    * ufshcd_memory_alloc - allocate memory for host memory space data structures
    * @hba: per adapter instance

@@ -774,8 +1075,8 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
   				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
 
   		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
-		hba->lrb[i].ucd_cmd_ptr =
-			(struct utp_upiu_cmd *)(cmd_descp + i);
+		hba->lrb[i].ucd_req_ptr =
+			(struct utp_upiu_req *)(cmd_descp + i);
   		hba->lrb[i].ucd_rsp_ptr =
   			(struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
   		hba->lrb[i].ucd_prdt_ptr =

@@ -961,6 +1262,38 @@ out:
   }
Quoted 13 lines

drivers/scsi/ufs/ufshcd.c out: · line 1274

Quoted 11 lines
drivers/scsi/ufs/ufshcd.c +10 -0
   /**
+ * ufshcd_validate_dev_connection() - Check device connection status
+ * @hba: per-adapter instance
+ *
+ * Send NOP OUT UPIU and wait for NOP IN response to check whether the
+ * device Transport Protocol (UTP) layer is ready after a reset.
+ * If the UTP layer at the device side is not initialized, it may
+ * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
+ * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
+ */
+static int ufshcd_validate_dev_connection(struct ufs_hba *hba)

I think ufshcd_verify_dev_init is close to standard description.

Okay.

Quoted 35 lines
Quoted 35 lines
drivers/scsi/ufs/ufshcd.c +24 -4
+{
+	int err = 0;
+	int retries;
+
+	mutex_lock(&hba->dev_cmd.lock);
+	for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
+		err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
+					       NOP_OUT_TIMEOUT);
+
+		if (!err || err == -ETIMEDOUT)
+			break;
+
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	if (err)
+		dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
+	return err;
+}
+
+/**
    * ufshcd_do_reset - reset the host controller
    * @hba: per adapter instance
    *

@@ -986,13 +1319,20 @@ static int ufshcd_do_reset(struct ufs_hba *hba)
   	for (tag = 0; tag < hba->nutrs; tag++) {
   		if (test_bit(tag, &hba->outstanding_reqs)) {
   			lrbp = &hba->lrb[tag];
-			scsi_dma_unmap(lrbp->cmd);
-			lrbp->cmd->result = DID_RESET << 16;
-			lrbp->cmd->scsi_done(lrbp->cmd);
-			lrbp->cmd = NULL;
+			if (lrbp->cmd) {
+				scsi_dma_unmap(lrbp->cmd);
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c static int ufshcd_do_reset(struct ufs_hba *hba) · line 1328

Quoted 5 lines
drivers/scsi/ufs/ufshcd.c +5 -0
+				lrbp->cmd->result = DID_RESET << 16;
+				lrbp->cmd->scsi_done(lrbp->cmd);
+				lrbp->cmd = NULL;
+				clear_bit_unlock(tag, &hba->lrb_in_use);
+			}

I know above.
But there is no relation to this patch.
Can be it moved to scsi: ufs: Fix device and host reset methods?

Yes, but it is basically to avoid NULL pointer derefernce in case someone picks this patch but not the other one.

Quoted 13 lines
Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +4 -0
   		}
   	}
 
+	/* complete device management command */
+	if (hba->dev_cmd.complete)
+		complete(hba->dev_cmd.complete);
+
   	/* clear outstanding request/task bit maps */
   	hba->outstanding_reqs = 0;
   	hba->outstanding_tasks = 0;

@@ -1199,27 +1539,37 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
Quoted 6 lines

drivers/scsi/ufs/ufshcd.c ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) · line 1542

Quoted 4 lines
drivers/scsi/ufs/ufshcd.c +0 -1
   	switch (ocs) {
   	case OCS_SUCCESS:
-
   		/* check if the returned transfer response is valid */

As replaced with new function, comment isn't valid. Remove or "get the TR response transaction type" seems proper.

Okay.

Quoted 103 lines
Quoted 103 lines
drivers/scsi/ufs/ufshcd.c +47 -27
-		result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
-		if (result) {
+		result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);
+
+		switch (result) {
+		case UPIU_TRANSACTION_RESPONSE:
+			/*
+			 * get the response UPIU result to extract
+			 * the SCSI command status
+			 */
+			result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
+
+			/*
+			 * get the result based on SCSI status response
+			 * to notify the SCSI midlayer of the command status
+			 */
+			scsi_status = result & MASK_SCSI_STATUS;
+			result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
+			break;
+		case UPIU_TRANSACTION_REJECT_UPIU:
+			/* TODO: handle Reject UPIU Response */
+			result = DID_ERROR << 16;
+			dev_err(hba->dev,
+				"Reject UPIU not fully implemented\n");
+			break;
+		default:
+			result = DID_ERROR << 16;
   			dev_err(hba->dev,
-				"Invalid response = %x\n", result);
+				"Unexpected request response code = %x\n",
+				result);
   			break;
   		}
-
-		/*
-		 * get the response UPIU result to extract
-		 * the SCSI command status
-		 */
-		result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);
-
-		/*
-		 * get the result based on SCSI status response
-		 * to notify the SCSI midlayer of the command status
-		 */
-		scsi_status = result & MASK_SCSI_STATUS;
-		result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
   		break;
   	case OCS_ABORTED:
   		result |= DID_ABORT << 16;

@@ -1259,28 +1609,37 @@ static void ufshcd_uic_cmd_compl(struct ufs_hba *hba)
    */
   static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
   {
-	struct ufshcd_lrb *lrb;
+	struct ufshcd_lrb *lrbp;
+	struct scsi_cmnd *cmd;
   	unsigned long completed_reqs;
   	u32 tr_doorbell;
   	int result;
   	int index;
+	bool int_aggr_reset = false;
 
-	lrb = hba->lrb;
   	tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
   	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;
 
   	for (index = 0; index < hba->nutrs; index++) {
   		if (test_bit(index, &completed_reqs)) {
-
-			result = ufshcd_transfer_rsp_status(hba, &lrb[index]);
-
-			if (lrb[index].cmd) {
-				scsi_dma_unmap(lrb[index].cmd);
-				lrb[index].cmd->result = result;
-				lrb[index].cmd->scsi_done(lrb[index].cmd);
-
+			lrbp = &hba->lrb[index];
+			cmd = lrbp->cmd;
+			/* Don't reset counters for interrupt cmd */
+			int_aggr_reset |= !lrbp->intr_cmd;
+
+			if (cmd) {
+				result = ufshcd_transfer_rsp_status(hba, lrbp);
+				scsi_dma_unmap(cmd);
+				cmd->result = result;
   				/* Mark completed command as NULL in LRB */
-				lrb[index].cmd = NULL;
+				lrbp->cmd = NULL;
+				clear_bit_unlock(index, &hba->lrb_in_use);
+				/* Do not touch lrbp after scsi done */
+				cmd->scsi_done(cmd);
+			} else if (lrbp->command_type ==
+					UTP_CMD_TYPE_DEV_MANAGE) {
+				if (hba->dev_cmd.complete)
+					complete(hba->dev_cmd.complete);
   			}
   		} /* end of if */
   	} /* end of for */

@@ -1288,8 +1647,12 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
   	/* clear corresponding bits of completed commands */
   	hba->outstanding_reqs ^= completed_reqs;
Quoted 11 lines

drivers/scsi/ufs/ufshcd.c static void ufshcd_transfer_req_compl(struct ufs_hba *hba) · line 1655

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +5 -1
+	/* we might have free'd some tags above */
+	wake_up(&hba->dev_cmd.tag_wq);
+
   	/* Reset interrupt aggregation counters */
-	ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
+	if (int_aggr_reset)
+		ufshcd_config_int_aggr(hba, INT_AGGR_RESET);

Do you assume that interrupt command(device management command) is completed alone? Of course, interrupt command is not counted in aggregation unlike regular command. We need to consider that interrupt command comes along with regular command? If right, ufshcd_config_int_aggr should not be skipped.

True. We are not skipping it. int_aggr_reset will be false only when there is single interrupt command completed.

Check the above part which reads -

for_all_completed_commands() {
   int_aggr_reset |= !lrbp->intr_cmd;
}
Quoted 6 lines
Quoted 2 lines

Even if one of the command in the iteration is not interrupt command (lrbp->intr_cmd is false) then int_aggr_reset is always true.

Clear!
But I confused it with your comment line. (/* Don't reset counters for interrupt cmd */) How about changing like below?
'Don't skip to reset counters if a regular command is present'

Makes sense.

Signature · 2 lines
Regards,
Sujit
#7 lore raw

RE: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

Quoted 134 lines · Sujit Reddy Thumma
Quoted 32 lines
Quoted 32 lines
Quoted 6 lines
Quoted 6 lines

+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs

Quoted 8 lines

drivers/scsi/ufs/ufshcd.c enum { · line 91

Quoted 6 lines

+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */

drivers/scsi/ufs/ufshcd.c +2 -0
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)

I feel like this function's role is to wait for clearing register (specially, doorbells). If you really don't intend to apply other all register, I think it would better to change the

function name.

Quoted 1 line

ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?

Although, this API is introduced in this patch and used only for clearing the doorbell, I have intentionally made it generic to avoid duplication of wait condition code in future (not just clearing but also for setting a bit). For example, when we write to HCE.ENABLE we wait for it turn to 1.

Quoted 7 lines

And if you like it, it could be more simple like below

static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us, unsigned int timeout_ms)

{
          unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
Quoted 5 lines
Quoted 2 lines

Jiffies on 100Hz systems have minimum granularity of 10ms. So we really wait for more 10ms even though the timeout_ms < 10ms.

Yes. Real timeout depends on system.
But normally actual wait will be maintained until 'ufshcd_readl' is done.
Timeout is valid for failure case. If we don't need to apply a strict timeout value, it's not bad.

Hmm.. make sense. Will take care in the next patchset.

Quoted 11 lines
Quoted 11 lines
Quoted 10 lines

          /* wakeup within 50us of expiry */
          const unsigned int expiry = 50;

          while (ufshcd_readl(hba, reg) & mask) {
                  usleep_range(interval_us, interval_us + expiry);
                  if (time_after(jiffies, timeout)) {
                          if (ufshcd_readl(hba, reg) & mask)
                                  return false;
Quoted 5 lines
Quoted 3 lines

I really want the caller to decide on what to do after the timeout. This helps in error handling cases where we try to clear off the entire door-bell register but only a few of the bits are cleared after timeout.

I don't know what we can do with the report of the partial success on clearing bit. It's just failure case. Isn't enough with false/true?

The point is, if a bit can't be cleared it can be regarded as a permanent failure (only for that request), otherwise, it can be retried with the same tag value.

Quoted 37 lines
Quoted 37 lines
Quoted 37 lines

                          else
                                  return true;
                  }
          }

          return true;
}
Quoted 28 lines
drivers/scsi/ufs/ufshcd.c +28 -0
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+

..

Quoted 26 lines
Quoted 22 lines
Quoted 13 lines
Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +13 -0
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c out: · line 806

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +7 -0
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);

4th argument should be (~mask) instead of '0', right?

Quoted 4 lines

True, but not really for this implementation. It breaks the check in in wait_for_register -
if ((val & mask) != val)

             dev_err(...);
Quoted 5 lines

Hmm, it seems complicated to use.
Ok. Is right the following about val as 4th argument?
- clear: val should be '0' regardless corresponding bit.
- set: val should be same with mask.
If the related comment is added, it will be helpful.

Thinking again it looks like it is complicated. How about changing the check to -

Quoted 7 lines

val = val & mask; /* ignore the bits we don't intend to wait on */ while (ufshcd_readl() & mask != val) {
sleep
}

Usage will be ~mask for clearing the bits, mask for setting the bits in the fourth argument.

Ok.
It's better for the caller.

Quoted 10 lines
Quoted 10 lines
Quoted 10 lines
Quoted 5 lines

Actually, mask value involves the corresponding bit to be cleared. So, 4th argument may be unnecessary.

As I described above, the wait_for_register can also be used to check if the value is set or not. In which case, we need 4th argument.

Quoted 1 line
Quoted 8 lines
Quoted 4 lines
Quoted 3 lines
Quoted 3 lines

drivers/scsi/ufs/ufshcd.c out: · line 808

Quoted 2 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;

Also, checking the result can be involved in ufshcd_wait_for_register.

Any comment?

Sorry I missed this. But the point was the same. To make wait_for_register() just to wait a definite time and not return any error condition when the bits don't turn as expected.

Comparing reg with mask can be done in 'ufshcd_wait_for_register' commonly. Currently the caller do the same.

Thanks,
Seungwon Jeon

author
#8 lore raw

Re: [PATCH V3 1/2] scsi: ufs: Add support for sending NOP OUT UPIU

Quoted 158 lines · Seungwon Jeon
Quoted 134 lines · Sujit Reddy Thumma
Quoted 32 lines
Quoted 32 lines
Quoted 6 lines
Quoted 6 lines

+ * ufshcd_wait_for_register - wait for register value to change
+ * @hba - per-adapter interface
+ * @reg - mmio register offset
+ * @mask - mask to apply to read register value
+ * @val - wait condition
+ * @interval_us - polling interval in microsecs

Quoted 8 lines

drivers/scsi/ufs/ufshcd.c enum { · line 91

Quoted 6 lines

+ * @timeout_ms - timeout in millisecs
+ *
+ * Returns final register value after iteration
+ */

drivers/scsi/ufs/ufshcd.c +2 -0
+static u32 ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
+		u32 val, unsigned long interval_us, unsigned long timeout_ms)

I feel like this function's role is to wait for clearing register (specially, doorbells). If you really don't intend to apply other all register, I think it would better to change the

function name.

Quoted 1 line

ex> ufshcd_wait_for_clear_doorbell or ufshcd_wait_for_clear_reg?

Although, this API is introduced in this patch and used only for clearing the doorbell, I have intentionally made it generic to avoid duplication of wait condition code in future (not just clearing but also for setting a bit). For example, when we write to HCE.ENABLE we wait for it turn to 1.

Quoted 7 lines

And if you like it, it could be more simple like below

static bool ufshcd_wait_for_clear_reg(struct ufs_hba *hba, u32 reg, u32 mask,
unsigned long interval_us, unsigned int timeout_ms)

{
           unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
Quoted 5 lines
Quoted 2 lines

Jiffies on 100Hz systems have minimum granularity of 10ms. So we really wait for more 10ms even though the timeout_ms < 10ms.

Yes. Real timeout depends on system.
But normally actual wait will be maintained until 'ufshcd_readl' is done.
Timeout is valid for failure case. If we don't need to apply a strict timeout value, it's not bad.

Hmm.. make sense. Will take care in the next patchset.

Quoted 11 lines
Quoted 11 lines
Quoted 10 lines

           /* wakeup within 50us of expiry */
           const unsigned int expiry = 50;

           while (ufshcd_readl(hba, reg) & mask) {
                   usleep_range(interval_us, interval_us + expiry);
                   if (time_after(jiffies, timeout)) {
                           if (ufshcd_readl(hba, reg) & mask)
                                   return false;
Quoted 5 lines
Quoted 3 lines

I really want the caller to decide on what to do after the timeout. This helps in error handling cases where we try to clear off the entire door-bell register but only a few of the bits are cleared after timeout.

I don't know what we can do with the report of the partial success on clearing bit. It's just failure case. Isn't enough with false/true?

The point is, if a bit can't be cleared it can be regarded as a permanent failure (only for that request), otherwise, it can be retried with the same tag value.

Quoted 37 lines
Quoted 37 lines
Quoted 37 lines

                           else
                                   return true;
                   }
           }

           return true;
}
Quoted 28 lines
drivers/scsi/ufs/ufshcd.c +28 -0
+{
+	u32 tmp;
+	ktime_t start;
+	unsigned long diff;
+
+	tmp = ufshcd_readl(hba, reg);
+
+	if ((val & mask) != val) {
+		dev_err(hba->dev, "%s: Invalid wait condition 0x%x\n",
+				__func__, val);
+		goto out;
+	}
+
+	start = ktime_get();
+	while ((tmp & mask) != val) {
+		/* wakeup within 50us of expiry */
+		usleep_range(interval_us, interval_us + 50);
+		tmp = ufshcd_readl(hba, reg);
+		diff = ktime_to_ms(ktime_sub(ktime_get(), start));
+		if (diff > timeout_ms) {
+			tmp = ufshcd_readl(hba, reg);
+			break;
+		}
+	}
+out:
+	return tmp;
+}
+

..

Quoted 26 lines
Quoted 22 lines
Quoted 13 lines
Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +13 -0
+static int
+ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
+{
+	int err = 0;
+	unsigned long flags;
+	u32 reg;
+	u32 mask = 1 << tag;
+
+	/* clear outstanding transaction before retry */
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	ufshcd_utrl_clear(hba, tag);
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+
Quoted 8 lines

drivers/scsi/ufs/ufshcd.c out: · line 806

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +7 -0
+	/*
+	 * wait for for h/w to clear corresponding bit in door-bell.
+	 * max. wait is 1 sec.
+	 */
+	reg = ufshcd_wait_for_register(hba,
+			REG_UTP_TRANSFER_REQ_DOOR_BELL,
+			mask, 0, 1000, 1000);

4th argument should be (~mask) instead of '0', right?

Quoted 4 lines

True, but not really for this implementation. It breaks the check in in wait_for_register -
if ((val & mask) != val)

              dev_err(...);
Quoted 5 lines

Hmm, it seems complicated to use.
Ok. Is right the following about val as 4th argument?
- clear: val should be '0' regardless corresponding bit.
- set: val should be same with mask.
If the related comment is added, it will be helpful.

Thinking again it looks like it is complicated. How about changing the check to -

Quoted 7 lines

val = val & mask; /* ignore the bits we don't intend to wait on */ while (ufshcd_readl() & mask != val) {
sleep
}

Usage will be ~mask for clearing the bits, mask for setting the bits in the fourth argument.

Ok.
It's better for the caller.

Quoted 13 lines
Quoted 13 lines
Quoted 13 lines
Quoted 5 lines

Actually, mask value involves the corresponding bit to be cleared. So, 4th argument may be unnecessary.

As I described above, the wait_for_register can also be used to check if the value is set or not. In which case, we need 4th argument.

Quoted 4 lines

drivers/scsi/ufs/ufshcd.c out: · line 808

Quoted 3 lines
drivers/scsi/ufs/ufshcd.c +2 -0
+	if ((reg & mask) == mask)
+		err = -ETIMEDOUT;

Also, checking the result can be involved in ufshcd_wait_for_register.

Quoted 7 lines
Quoted 5 lines
Quoted 1 line

Any comment?

Sorry I missed this. But the point was the same. To make wait_for_register() just to wait a definite time and not return any error condition when the bits don't turn as expected.

Comparing reg with mask can be done in 'ufshcd_wait_for_register' commonly. Currently the caller do the same.

Hmm.. you don't seem to agree to my point earlier mentioned

">>>> I really want the caller to decide on what to do after the timeout.

Quoted 8 lines
Quoted 8 lines
Quoted 4 lines
Quoted 2 lines

This helps in error handling cases where we try to clear off the entire door-bell register but only a few of the bits are cleared after timeout.

I don't know what we can do with the report of the partial success on clearing bit. It's just failure case. Isn't enough with false/true?

The point is, if a bit can't be cleared it can be regarded as a permanent failure (only for that request), otherwise, it can be retried with the same tag value."

Since there is no real use case as of now. I will move the error check to the wait_for_register.

Signature · 2 lines
Regards,
Sujit
author
#9 lore raw

PATCH v3 2/2 scsi: ufs: Set fDeviceInit flag to initiate device initialization

In reply to Sujit Reddy Thumma

From: Dolev Raviv <[email protected]>

Allow UFS device to complete its initialization and accept SCSI commands by setting fDeviceInit flag. The device may take time for this operation and hence the host should poll until fDeviceInit flag is toggled to zero. This step is mandated by UFS device specification for device initialization completion.

Signed-off-by Dolev Raviv <[email protected]>
Signed-off-by Sujit Reddy Thumma <[email protected]>
---
 drivers/scsi/ufs/ufs.h    |   88 +++++++++++++-
 drivers/scsi/ufs/ufshcd.c |  292 ++++++++++++++++++++++++++++++++++++++++++++-
 drivers/scsi/ufs/ufshcd.h |   14 ++
 drivers/scsi/ufs/ufshci.h |    2 +-
 4 files changed, 390 insertions(+), 6 deletions(-)
drivers/scsi/ufs/ufs.h +84 -4
index 14c0a4e..db5bde4 100644
@@ -43,6 +43,8 @@
 #define GENERAL_UPIU_REQUEST_SIZE 32
 #define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
 					(GENERAL_UPIU_REQUEST_SIZE))
+#define QUERY_OSF_SIZE			((GENERAL_UPIU_REQUEST_SIZE) - \
+					(sizeof(struct utp_upiu_header)))
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
 			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\

@@ -68,7 +70,7 @@ enum {
 	UPIU_TRANSACTION_COMMAND	= 0x01,
 	UPIU_TRANSACTION_DATA_OUT	= 0x02,
 	UPIU_TRANSACTION_TASK_REQ	= 0x04,
-	UPIU_TRANSACTION_QUERY_REQ	= 0x26,
+	UPIU_TRANSACTION_QUERY_REQ	= 0x16,
 };
 
 /* UTP UPIU Transaction Codes Target to Initiator */

@@ -97,8 +99,19 @@ enum {
 	UPIU_TASK_ATTR_ACA	= 0x03,
 };
 
-/* UTP QUERY Transaction Specific Fields OpCode */
+/* UPIU Query request function */
 enum {
+	UPIU_QUERY_FUNC_STANDARD_READ_REQUEST = 0x01,
+	UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST = 0x81,
+};
+
+/* Flag idn for Query Requests*/
+enum flag_idn {
+	QUERY_FLAG_IDN_FDEVICEINIT = 0x01,
+};
+
+/* UTP QUERY Transaction Specific Fields OpCode */
+enum query_opcode {
 	UPIU_QUERY_OPCODE_NOP		= 0x0,
 	UPIU_QUERY_OPCODE_READ_DESC	= 0x1,
 	UPIU_QUERY_OPCODE_WRITE_DESC	= 0x2,

@@ -110,6 +123,21 @@ enum {
 	UPIU_QUERY_OPCODE_TOGGLE_FLAG	= 0x8,
 };
 
+/* Query response result code */
+enum {
+	QUERY_RESULT_SUCCESS			= 0x00,
+	QUERY_RESULT_NOT_READABLE		= 0xF6,
+	QUERY_RESULT_NOT_WRITEABLE		= 0xF7,
+	QUERY_RESULT_ALREADY_WRITTEN		= 0xF8,
+	QUERY_RESULT_INVALID_LENGTH		= 0xF9,
+	QUERY_RESULT_INVALID_VALUE		= 0xFA,
+	QUERY_RESULT_INVALID_SELECTOR		= 0xFB,
+	QUERY_RESULT_INVALID_INDEX		= 0xFC,
+	QUERY_RESULT_INVALID_IDN		= 0xFD,
+	QUERY_RESULT_INVALID_OPCODE		= 0xFE,
+	QUERY_RESULT_GENERAL_FAILURE		= 0xFF,
+};
+
 /* UTP Transfer Request Command Type (CT) */
 enum {
 	UPIU_COMMAND_SET_TYPE_SCSI	= 0x0,

@@ -127,6 +155,7 @@ enum {
 	MASK_SCSI_STATUS	= 0xFF,
 	MASK_TASK_RESPONSE	= 0xFF00,
 	MASK_RSP_UPIU_RESULT	= 0xFFFF,
+	MASK_QUERY_DATA_SEG_LEN	= 0xFFFF,
 };
 
 /* Task management service response */

@@ -160,13 +189,40 @@ struct utp_upiu_cmd {
 };
 
 /**
+ * struct utp_upiu_query - upiu request buffer structure for
+ * query request.
+ * @opcode: command to perform B-0
+ * @idn: a value that indicates the particular type of data B-1
+ * @index: Index to further identify data B-2
+ * @selector: Index to further identify data B-3
+ * @reserved_osf: spec reserved field B-4,5
+ * @length: number of descriptor bytes to read/write B-6,7
+ * @value: Attribute value to be written DW-5
+ * @reserved: spec reserved DW-6,7
+ */
+struct utp_upiu_query {
+	u8 opcode;
+	u8 idn;
+	u8 index;
+	u8 selector;
+	u16 reserved_osf;
+	u16 length;
+	u32 value;
+	u32 reserved[2];
+};
+
+/**
  * struct utp_upiu_req - general upiu request structure
  * @header:UPIU header structure DW-0 to DW-2
  * @sc: fields structure for scsi command DW-3 to DW-7
+ * @qr: fields structure for query request DW-3 to DW-7
  */
 struct utp_upiu_req {
 	struct utp_upiu_header header;
-	struct utp_upiu_cmd sc;
+	union {
+		struct utp_upiu_cmd sc;
+		struct utp_upiu_query qr;
+	};
 };
 
 /**

@@ -187,10 +243,14 @@ struct utp_cmd_rsp {
  * struct utp_upiu_rsp - general upiu response structure
  * @header: UPIU header structure DW-0 to DW-2
  * @sr: fields structure for scsi command DW-3 to DW-12
+ * @qr: fields structure for query request DW-3 to DW-7
  */
 struct utp_upiu_rsp {
 	struct utp_upiu_header header;
-	struct utp_cmd_rsp sr;
+	union {
+		struct utp_cmd_rsp sr;
+		struct utp_upiu_query qr;
+	};
 };
 
 /**

@@ -223,4 +283,24 @@ struct utp_upiu_task_rsp {
 	u32 reserved[3];
 };
 
+/**
+ * struct ufs_query_req - parameters for building a query request
+ * @query_func: UPIU header query function
+ * @upiu_req: the query request data
+ */
+struct ufs_query_req {
+	u8 query_func;
+	struct utp_upiu_query upiu_req;
+};
+
+/**
+ * struct ufs_query_resp - UPIU QUERY
+ * @response: device response code
+ * @upiu_res: query response data
+ */
+struct ufs_query_res {
+	u8 response;
+	struct utp_upiu_query upiu_res;
+};
+
 #endif /* End of Header */
drivers/scsi/ufs/ufshcd.c +291 -1

340 lines not on this page · raw message

drivers/scsi/ufs/ufshcd.h +14 -0
index c750a90..c6aeb6d 100644
@@ -70,6 +70,7 @@
 
 enum dev_cmd_type {
 	DEV_CMD_TYPE_NOP		= 0x0,
+	DEV_CMD_TYPE_QUERY		= 0x1,
 };
 
 /**

@@ -125,6 +126,18 @@ struct ufshcd_lrb {
 };
 
 /**
+ * struct ufs_query - holds relevent data structures for query request
+ * @request: request upiu and function
+ * @descriptor: buffer for sending/receiving descriptor
+ * @response: response upiu and response
+ */
+struct ufs_query {
+	struct ufs_query_req *request;
+	u8 *descriptor;
+	struct ufs_query_res *response;
+};
+
+/**
  * struct ufs_dev_cmd - all assosiated fields with device management commands
  * @type: device management command type - Query, NOP OUT
  * @lock: lock to allow one command at a time

@@ -136,6 +149,7 @@ struct ufs_dev_cmd {
 	struct mutex lock;
 	struct completion *complete;
 	wait_queue_head_t tag_wq;
+	struct ufs_query query;
 };
 
 /**
drivers/scsi/ufs/ufshci.h +1 -1
index d5c5f14..f1e1b74 100644
@@ -39,7 +39,7 @@
 enum {
 	TASK_REQ_UPIU_SIZE_DWORDS	= 8,
 	TASK_RSP_UPIU_SIZE_DWORDS	= 8,
-	ALIGNED_UPIU_SIZE		= 128,
+	ALIGNED_UPIU_SIZE		= 512,
 };
 
 /* UFSHCI Registers */
Signature · 2 lines
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation.
Tested-by on v3 2/2
#10 lore raw

Re: [PATCH V3 2/2] scsi: ufs: Set fDeviceInit flag to initiate device initialization

Tested-by Maya Erez <[email protected]>
Quoted 599 lines

From: Dolev Raviv <[email protected]>

Allow UFS device to complete its initialization and accept SCSI commands by setting fDeviceInit flag. The device may take time for this operation and hence the host should poll until fDeviceInit flag is toggled to zero. This step is mandated by UFS device specification for device initialization completion.

Signed-off-by Dolev Raviv <[email protected]>
Signed-off-by Sujit Reddy Thumma <[email protected]>
---
 drivers/scsi/ufs/ufs.h    |   88 +++++++++++++-
 drivers/scsi/ufs/ufshcd.c |  292
++++++++++++++++++++++++++++++++++++++++++++-
 drivers/scsi/ufs/ufshcd.h |   14 ++
 drivers/scsi/ufs/ufshci.h |    2 +-
 4 files changed, 390 insertions(+), 6 deletions(-)
drivers/scsi/ufs/ufs.h +84 -4
index 14c0a4e..db5bde4 100644
@@ -43,6 +43,8 @@
 #define GENERAL_UPIU_REQUEST_SIZE 32
 #define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
 					(GENERAL_UPIU_REQUEST_SIZE))
+#define QUERY_OSF_SIZE			((GENERAL_UPIU_REQUEST_SIZE) - \
+					(sizeof(struct utp_upiu_header)))
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
 			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\

@@ -68,7 +70,7 @@ enum {
 	UPIU_TRANSACTION_COMMAND	= 0x01,
 	UPIU_TRANSACTION_DATA_OUT	= 0x02,
 	UPIU_TRANSACTION_TASK_REQ	= 0x04,
-	UPIU_TRANSACTION_QUERY_REQ	= 0x26,
+	UPIU_TRANSACTION_QUERY_REQ	= 0x16,
 };
 
 /* UTP UPIU Transaction Codes Target to Initiator */

@@ -97,8 +99,19 @@ enum {
 	UPIU_TASK_ATTR_ACA	= 0x03,
 };
 
-/* UTP QUERY Transaction Specific Fields OpCode */
+/* UPIU Query request function */
 enum {
+	UPIU_QUERY_FUNC_STANDARD_READ_REQUEST = 0x01,
+	UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST = 0x81,
+};
+
+/* Flag idn for Query Requests*/
+enum flag_idn {
+	QUERY_FLAG_IDN_FDEVICEINIT = 0x01,
+};
+
+/* UTP QUERY Transaction Specific Fields OpCode */
+enum query_opcode {
 	UPIU_QUERY_OPCODE_NOP		= 0x0,
 	UPIU_QUERY_OPCODE_READ_DESC	= 0x1,
 	UPIU_QUERY_OPCODE_WRITE_DESC	= 0x2,

@@ -110,6 +123,21 @@ enum {
 	UPIU_QUERY_OPCODE_TOGGLE_FLAG	= 0x8,
 };
 
+/* Query response result code */
+enum {
+	QUERY_RESULT_SUCCESS			= 0x00,
+	QUERY_RESULT_NOT_READABLE		= 0xF6,
+	QUERY_RESULT_NOT_WRITEABLE		= 0xF7,
+	QUERY_RESULT_ALREADY_WRITTEN		= 0xF8,
+	QUERY_RESULT_INVALID_LENGTH		= 0xF9,
+	QUERY_RESULT_INVALID_VALUE		= 0xFA,
+	QUERY_RESULT_INVALID_SELECTOR		= 0xFB,
+	QUERY_RESULT_INVALID_INDEX		= 0xFC,
+	QUERY_RESULT_INVALID_IDN		= 0xFD,
+	QUERY_RESULT_INVALID_OPCODE		= 0xFE,
+	QUERY_RESULT_GENERAL_FAILURE		= 0xFF,
+};
+
 /* UTP Transfer Request Command Type (CT) */
 enum {
 	UPIU_COMMAND_SET_TYPE_SCSI	= 0x0,

@@ -127,6 +155,7 @@ enum {
 	MASK_SCSI_STATUS	= 0xFF,
 	MASK_TASK_RESPONSE	= 0xFF00,
 	MASK_RSP_UPIU_RESULT	= 0xFFFF,
+	MASK_QUERY_DATA_SEG_LEN	= 0xFFFF,
 };
 
 /* Task management service response */

@@ -160,13 +189,40 @@ struct utp_upiu_cmd {
 };
 
 /**
+ * struct utp_upiu_query - upiu request buffer structure for
+ * query request.
+ * @opcode: command to perform B-0
+ * @idn: a value that indicates the particular type of data B-1
+ * @index: Index to further identify data B-2
+ * @selector: Index to further identify data B-3
+ * @reserved_osf: spec reserved field B-4,5
+ * @length: number of descriptor bytes to read/write B-6,7
+ * @value: Attribute value to be written DW-5
+ * @reserved: spec reserved DW-6,7
+ */
+struct utp_upiu_query {
+	u8 opcode;
+	u8 idn;
+	u8 index;
+	u8 selector;
+	u16 reserved_osf;
+	u16 length;
+	u32 value;
+	u32 reserved[2];
+};
+
+/**
  * struct utp_upiu_req - general upiu request structure
  * @header:UPIU header structure DW-0 to DW-2
  * @sc: fields structure for scsi command DW-3 to DW-7
+ * @qr: fields structure for query request DW-3 to DW-7
  */
 struct utp_upiu_req {
 	struct utp_upiu_header header;
-	struct utp_upiu_cmd sc;
+	union {
+		struct utp_upiu_cmd sc;
+		struct utp_upiu_query qr;
+	};
 };
 
 /**

@@ -187,10 +243,14 @@ struct utp_cmd_rsp {
  * struct utp_upiu_rsp - general upiu response structure
  * @header: UPIU header structure DW-0 to DW-2
  * @sr: fields structure for scsi command DW-3 to DW-12
+ * @qr: fields structure for query request DW-3 to DW-7
  */
 struct utp_upiu_rsp {
 	struct utp_upiu_header header;
-	struct utp_cmd_rsp sr;
+	union {
+		struct utp_cmd_rsp sr;
+		struct utp_upiu_query qr;
+	};
 };
 
 /**

@@ -223,4 +283,24 @@ struct utp_upiu_task_rsp {
 	u32 reserved[3];
 };
 
+/**
+ * struct ufs_query_req - parameters for building a query request
+ * @query_func: UPIU header query function
+ * @upiu_req: the query request data
+ */
+struct ufs_query_req {
+	u8 query_func;
+	struct utp_upiu_query upiu_req;
+};
+
+/**
+ * struct ufs_query_resp - UPIU QUERY
+ * @response: device response code
+ * @upiu_res: query response data
+ */
+struct ufs_query_res {
+	u8 response;
+	struct utp_upiu_query upiu_res;
+};
+
 #endif /* End of Header */
drivers/scsi/ufs/ufshcd.c +65 -0
index 3f482b6..96ccb28 100644
@@ -48,6 +48,14 @@
 /* Timeout after 30 msecs if NOP OUT hangs without response */
 #define NOP_OUT_TIMEOUT    30 /* msecs */
 
+/* Query request retries */
+#define QUERY_REQ_RETRIES 10
+/* Query request timeout */
+#define QUERY_REQ_TIMEOUT 30 /* msec */
+
+/* Expose the flag value from utp_upiu_query.value */
+#define MASK_QUERY_UPIU_FLAG_LOC 0xFF
+
 enum {
 	UFSHCD_MAX_CHANNEL	= 0,
 	UFSHCD_MAX_ID		= 1,

@@ -348,6 +356,63 @@ static inline void ufshcd_copy_sense_data(struct
 ufshcd_lrb *lrbp)
 }
 
 /**
+ * ufshcd_query_to_cpu() - formats the buffer to native cpu endian
+ * @response: upiu query response to convert
+ */
+static inline void ufshcd_query_to_cpu(struct utp_upiu_query *response)
+{
+	response->length = be16_to_cpu(response->length);
+	response->value = be32_to_cpu(response->value);
+}
+
+/**
+ * ufshcd_query_to_be() - formats the buffer to big endian
+ * @request: upiu query request to convert
+ */
+static inline void ufshcd_query_to_be(struct utp_upiu_query *request)
+{
+	request->length = cpu_to_be16(request->length);
+	request->value = cpu_to_be32(request->value);
+}
+
+/**
+ * ufshcd_copy_query_response() - Copy the Query Response and the data
+ * descriptor
+ * @hba: per adapter instance
+ * @lrb - pointer to local reference block
+ */
+static
+void ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb
 *lrbp)
+{
+	struct ufs_query_res *query_res = hba->dev_cmd.query.response;
+
+	/* Get the UPIU response */
+	if (query_res) {
+		query_res->response = ufshcd_get_rsp_upiu_result(
+			lrbp->ucd_rsp_ptr) >> UPIU_RSP_CODE_OFFSET;
+
+		memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr,
+			QUERY_OSF_SIZE);
+		ufshcd_query_to_cpu(&query_res->upiu_res);
+	}
+
+	/* Get the descriptor */
+	if (hba->dev_cmd.query.descriptor && lrbp->ucd_rsp_ptr->qr.opcode ==
+			UPIU_QUERY_OPCODE_READ_DESC) {
+		u8 *descp = (u8 *)&lrbp->ucd_rsp_ptr +
+				GENERAL_UPIU_REQUEST_SIZE;
+		u16 len;
+
+		/* data segment length */
+		len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2) &
+						MASK_QUERY_DATA_SEG_LEN;
+
+		memcpy(hba->dev_cmd.query.descriptor, descp,
+			min_t(u16, len, UPIU_HEADER_DATA_SEGMENT_MAX_SIZE));
+	}
+}
+
+/**
  * ufshcd_hba_capabilities - Read controller capabilities

* @hba: per adapter instance
*/

drivers/scsi/ufs/ufshcd.c +40 -0
@@ -629,6 +694,46 @@ void ufshcd_prepare_utp_scsi_cmd_upiu(struct
 ufshcd_lrb *lrbp, u32 upiu_flags)
 		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
 }
 
+/**
+ * ufshcd_prepare_utp_query_req_upiu() - fills the utp_transfer_req_desc,
+ * for query requsts
+ * @hba: UFS hba
+ * @lrbp: local reference block pointer
+ * @upiu_flags: flags
+ */
+static void ufshcd_prepare_utp_query_req_upiu(struct ufs_hba *hba,
+					struct ufshcd_lrb *lrbp,
+					u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+	u16 len = hba->dev_cmd.query.request->upiu_req.length;
+	u8 *descp = (u8 *)lrbp->ucd_req_ptr + GENERAL_UPIU_REQUEST_SIZE;
+
+	/* Query request header */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_QUERY_REQ, upiu_flags,
+			lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+			0, hba->dev_cmd.query.request->query_func, 0, 0);
+
+	/* Data segment length */
+	ucd_req_ptr->header.dword_2 = UPIU_HEADER_DWORD(
+			0, 0, len >> 8, (u8)len);
+
+	/* Copy the Query Request buffer as is */
+	memcpy(&lrbp->ucd_req_ptr->qr, &hba->dev_cmd.query.request->upiu_req,
+			QUERY_OSF_SIZE);
+	ufshcd_query_to_be(&lrbp->ucd_req_ptr->qr);
+
+	/* Copy the Descriptor */
+	if ((hba->dev_cmd.query.descriptor != NULL) && (len > 0) &&
+		(hba->dev_cmd.query.request->upiu_req.opcode ==
+					UPIU_QUERY_OPCODE_WRITE_DESC)) {
+		memcpy(descp, hba->dev_cmd.query.descriptor,
+			min_t(u16, len, UPIU_HEADER_DATA_SEGMENT_MAX_SIZE));
+	}
+}
+
 static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
 {
drivers/scsi/ufs/ufshcd.c +4 -1
 	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;

@@ -663,7 +768,10 @@ static int ufshcd_compose_upiu(struct ufs_hba *hba,
 struct ufshcd_lrb *lrbp)
 		break;
 	case UTP_CMD_TYPE_DEV_MANAGE:
 		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
-		if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_QUERY)
+			ufshcd_prepare_utp_query_req_upiu(
+					hba, lrbp, upiu_flags);
+		else if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
 			ufshcd_prepare_utp_nop_upiu(lrbp);
 		else
drivers/scsi/ufs/ufshcd.c +3 -0
 			ret = -EINVAL;

@@ -831,6 +939,9 @@ ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct
 ufshcd_lrb *lrbp)
 					__func__, resp);
 		}
 		break;
+	case UPIU_TRANSACTION_QUERY_RSP:
+		ufshcd_copy_query_response(hba, lrbp);
+		break;
 	case UPIU_TRANSACTION_REJECT_UPIU:
 		/* TODO: handle Reject UPIU Response */
drivers/scsi/ufs/ufshcd.c +9 -0
 		err = -EPERM;

@@ -941,6 +1052,128 @@ out_put_tag:
 }
 
 /**
+ * ufshcd_query_request() - API for issuing query request to the device.
+ * @hba: ufs driver context
+ * @query: params for query request
+ * @descriptor: buffer for sending/receiving descriptor
+ * @retries: number of times to try executing the command
+ *
+ * All necessary fields for issuing a query and receiving its response
+ * are stored in the UFS hba struct. We can use this method since we know
+ * there is only one active query request or any device management

command
+ * at all times.
+ */

drivers/scsi/ufs/ufshcd.c +33 -0
+static int ufshcd_send_query_request(struct ufs_hba *hba,
+					struct ufs_query_req *query,
+					u8 *descriptor,
+					struct ufs_query_res *response)
+{
+	int ret;
+
+	BUG_ON(!hba);
+	if (!query || !response) {
+		dev_err(hba->dev,
+			"%s: NULL pointer query = %p, response = %p\n",
+			__func__, query, response);
+		return -EINVAL;
+	}
+
+	mutex_lock(&hba->dev_cmd.lock);
+	hba->dev_cmd.query.request = query;
+	hba->dev_cmd.query.response = response;
+	hba->dev_cmd.query.descriptor = descriptor;
+
+	ret = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY,
+					QUERY_REQ_TIMEOUT);
+
+	hba->dev_cmd.query.request = NULL;
+	hba->dev_cmd.query.response = NULL;
+	hba->dev_cmd.query.descriptor = NULL;
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	return ret;
+}
+
+/**
+ * ufshcd_query_flag() - Helper function for composing flag query

requests
+ * hba: per-adapter instance
+ * query_opcode: flag query to perform
+ * idn: flag idn to access
+ * flag_res: the flag value after the query request completes
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,

drivers/scsi/ufs/ufshcd.c +70 -0
+			enum flag_idn idn, bool *flag_res)
+{
+	struct ufs_query_req *query;
+	struct ufs_query_res *response;
+	int err = -ENOMEM;
+
+	query = kzalloc(sizeof(struct ufs_query_req), GFP_KERNEL);
+	if (!query) {
+		dev_err(hba->dev,
+			"%s: Failed allocating ufs_query_req instance\n",
+			__func__);
+		goto out_no_mem;
+	}
+	response = kzalloc(sizeof(struct ufs_query_res), GFP_KERNEL);
+	if (!response) {
+		dev_err(hba->dev,
+			"%s: Failed allocating ufs_query_res instance\n",
+			__func__);
+		goto out_free_query;
+	}
+
+	switch (opcode) {
+	case UPIU_QUERY_OPCODE_SET_FLAG:
+	case UPIU_QUERY_OPCODE_CLEAR_FLAG:
+	case UPIU_QUERY_OPCODE_TOGGLE_FLAG:
+		query->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+		break;
+	case UPIU_QUERY_OPCODE_READ_FLAG:
+		query->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+		if (!flag_res) {
+			/* No dummy reads */
+			dev_err(hba->dev, "%s: Invalid argument for read request\n",
+					__func__);
+			err = -EINVAL;
+			goto out;
+		}
+		break;
+	default:
+		dev_err(hba->dev,
+			"%s: Expected query flag opcode but got = %d\n",
+			__func__, opcode);
+		err = -EINVAL;
+		goto out;
+	}
+	query->upiu_req.opcode = opcode;
+	query->upiu_req.idn = idn;
+
+	/* Send query request */
+	err = ufshcd_send_query_request(hba, query, NULL, response);
+
+	if (err) {
+		dev_err(hba->dev,
+			"%s: Sending flag query for idn %d failed, err = %d\n",
+			__func__, idn, err);
+		goto out;
+	}
+
+	if (flag_res)
+		*flag_res = (response->upiu_res.value &
+				MASK_QUERY_UPIU_FLAG_LOC) & 0x1;
+
+out:
+	kfree(response);
+out_free_query:
+	kfree(query);
+out_no_mem:
+	return err;
+}
+
+/**
  * ufshcd_memory_alloc - allocate memory for host memory space data

structures
* @hba: per adapter instance
*

drivers/scsi/ufs/ufshcd.c +53 -0
@@ -1110,6 +1343,59 @@ static int ufshcd_dme_link_startup(struct ufs_hba
 *hba)
 }
 
 /**
+ * ufshcd_validate_device_init() - checks device readiness
+ * hba: per-adapter instance
+ *
+ * Set fDeviceInit flag, than, query the flag until the device clears the
+ * flag.
+ */
+static int ufshcd_validate_device_init(struct ufs_hba *hba)
+{
+	int i, retries, err = 0;
+	bool flag_res = 0;
+
+	for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+		/* Set the fDeviceIntit flag */
+		err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
+					QUERY_FLAG_IDN_FDEVICEINIT, &flag_res);
+		if (!err || err == -ETIMEDOUT)
+			break;
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	if (err) {
+		dev_err(hba->dev,
+			"%s setting fDeviceInit flag failed with error %d\n",
+			__func__, err);
+		goto out;
+	}
+
+	/* poll for max. 100 iterations for fDeviceInit flag to clear */
+	for (i = 0; i < 100 && !err && flag_res; i++) {
+		retries = QUERY_REQ_RETRIES;
+		for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+			err = ufshcd_query_flag(hba,
+					UPIU_QUERY_OPCODE_READ_FLAG,
+					QUERY_FLAG_IDN_FDEVICEINIT, &flag_res);
+			if (!err || err == -ETIMEDOUT)
+				break;
+			dev_dbg(hba->dev, "%s: error %d retrying\n", __func__,
+					err);
+		}
+	}
+	if (err)
+		dev_err(hba->dev,
+			"%s reading fDeviceInit flag failed with error %d\n",
+			__func__, err);
+	else if (flag_res)
+		dev_err(hba->dev,
+			"%s fDeviceInit was not cleared by the device\n",
+			__func__);
+
+out:
+	return err;
+}
+
+/**
  * ufshcd_make_hba_operational - Make UFS controller operational
  * @hba: per adapter instance

*

drivers/scsi/ufs/ufshcd.c +4 -0
@@ -1962,6 +2248,10 @@ static void ufshcd_async_scan(void *data,
 async_cookie_t cookie)
 	if (ret)
 		goto out;
 
+	ret = ufshcd_validate_device_init(hba);
+	if (ret)
+		goto out;
+
 	scsi_scan_host(hba->host);
 out:
drivers/scsi/ufs/ufshcd.c +0 -0
 	return;
drivers/scsi/ufs/ufshcd.h +13 -0
index c750a90..c6aeb6d 100644
@@ -70,6 +70,7 @@
 
 enum dev_cmd_type {
 	DEV_CMD_TYPE_NOP		= 0x0,
+	DEV_CMD_TYPE_QUERY		= 0x1,
 };
 
 /**

@@ -125,6 +126,18 @@ struct ufshcd_lrb {
 };
 
 /**
+ * struct ufs_query - holds relevent data structures for query request
+ * @request: request upiu and function
+ * @descriptor: buffer for sending/receiving descriptor
+ * @response: response upiu and response
+ */
+struct ufs_query {
+	struct ufs_query_req *request;
+	u8 *descriptor;
+	struct ufs_query_res *response;
+};
+
+/**
  * struct ufs_dev_cmd - all assosiated fields with device management

commands
* @type: device management command type - Query, NOP OUT
* @lock: lock to allow one command at a time

drivers/scsi/ufs/ufshcd.h +1 -0
@@ -136,6 +149,7 @@ struct ufs_dev_cmd {
 	struct mutex lock;
 	struct completion *complete;
 	wait_queue_head_t tag_wq;
+	struct ufs_query query;
 };
 
 /**
drivers/scsi/ufs/ufshci.h +1 -2
index d5c5f14..f1e1b74 100644
@@ -39,7 +39,7 @@
 enum {
 	TASK_REQ_UPIU_SIZE_DWORDS	= 8,
 	TASK_RSP_UPIU_SIZE_DWORDS	= 8,
-	ALIGNED_UPIU_SIZE		= 128,
+	ALIGNED_UPIU_SIZE		= 512,
 };
 
 /* UFSHCI Registers */
--

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Signature · 3 lines
Maya Erez
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
#11 lore raw

RE: [PATCH V3 2/2] scsi: ufs: Set fDeviceInit flag to initiate device initialization

In reply to Sujit Reddy Thumma
Quoted 391 lines · Sujit Reddy Thumma

From: Dolev Raviv <[email protected]>

Allow UFS device to complete its initialization and accept SCSI commands by setting fDeviceInit flag. The device may take time for this operation and hence the host should poll until fDeviceInit flag is toggled to zero. This step is mandated by UFS device specification for device initialization completion.

Signed-off-by Dolev Raviv <[email protected]>
Signed-off-by Sujit Reddy Thumma <[email protected]>
---
 drivers/scsi/ufs/ufs.h    |   88 +++++++++++++-
 drivers/scsi/ufs/ufshcd.c |  292 ++++++++++++++++++++++++++++++++++++++++++++-
 drivers/scsi/ufs/ufshcd.h |   14 ++
 drivers/scsi/ufs/ufshci.h |    2 +-
 4 files changed, 390 insertions(+), 6 deletions(-)
drivers/scsi/ufs/ufs.h +84 -4
index 14c0a4e..db5bde4 100644
@@ -43,6 +43,8 @@
 #define GENERAL_UPIU_REQUEST_SIZE 32
 #define UPIU_HEADER_DATA_SEGMENT_MAX_SIZE	((ALIGNED_UPIU_SIZE) - \
 					(GENERAL_UPIU_REQUEST_SIZE))
+#define QUERY_OSF_SIZE			((GENERAL_UPIU_REQUEST_SIZE) - \
+					(sizeof(struct utp_upiu_header)))
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
 			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\

@@ -68,7 +70,7 @@ enum {
 	UPIU_TRANSACTION_COMMAND	= 0x01,
 	UPIU_TRANSACTION_DATA_OUT	= 0x02,
 	UPIU_TRANSACTION_TASK_REQ	= 0x04,
-	UPIU_TRANSACTION_QUERY_REQ	= 0x26,
+	UPIU_TRANSACTION_QUERY_REQ	= 0x16,
 };
 
 /* UTP UPIU Transaction Codes Target to Initiator */

@@ -97,8 +99,19 @@ enum {
 	UPIU_TASK_ATTR_ACA	= 0x03,
 };
 
-/* UTP QUERY Transaction Specific Fields OpCode */
+/* UPIU Query request function */
 enum {
+	UPIU_QUERY_FUNC_STANDARD_READ_REQUEST = 0x01,
+	UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST = 0x81,
+};
+
+/* Flag idn for Query Requests*/
+enum flag_idn {
+	QUERY_FLAG_IDN_FDEVICEINIT = 0x01,
+};
+
+/* UTP QUERY Transaction Specific Fields OpCode */
+enum query_opcode {
 	UPIU_QUERY_OPCODE_NOP		= 0x0,
 	UPIU_QUERY_OPCODE_READ_DESC	= 0x1,
 	UPIU_QUERY_OPCODE_WRITE_DESC	= 0x2,

@@ -110,6 +123,21 @@ enum {
 	UPIU_QUERY_OPCODE_TOGGLE_FLAG	= 0x8,
 };
 
+/* Query response result code */
+enum {
+	QUERY_RESULT_SUCCESS			= 0x00,
+	QUERY_RESULT_NOT_READABLE		= 0xF6,
+	QUERY_RESULT_NOT_WRITEABLE		= 0xF7,
+	QUERY_RESULT_ALREADY_WRITTEN		= 0xF8,
+	QUERY_RESULT_INVALID_LENGTH		= 0xF9,
+	QUERY_RESULT_INVALID_VALUE		= 0xFA,
+	QUERY_RESULT_INVALID_SELECTOR		= 0xFB,
+	QUERY_RESULT_INVALID_INDEX		= 0xFC,
+	QUERY_RESULT_INVALID_IDN		= 0xFD,
+	QUERY_RESULT_INVALID_OPCODE		= 0xFE,
+	QUERY_RESULT_GENERAL_FAILURE		= 0xFF,
+};
+
 /* UTP Transfer Request Command Type (CT) */
 enum {
 	UPIU_COMMAND_SET_TYPE_SCSI	= 0x0,

@@ -127,6 +155,7 @@ enum {
 	MASK_SCSI_STATUS	= 0xFF,
 	MASK_TASK_RESPONSE	= 0xFF00,
 	MASK_RSP_UPIU_RESULT	= 0xFFFF,
+	MASK_QUERY_DATA_SEG_LEN	= 0xFFFF,
 };
 
 /* Task management service response */

@@ -160,13 +189,40 @@ struct utp_upiu_cmd {
 };
 
 /**
+ * struct utp_upiu_query - upiu request buffer structure for
+ * query request.
+ * @opcode: command to perform B-0
+ * @idn: a value that indicates the particular type of data B-1
+ * @index: Index to further identify data B-2
+ * @selector: Index to further identify data B-3
+ * @reserved_osf: spec reserved field B-4,5
+ * @length: number of descriptor bytes to read/write B-6,7
+ * @value: Attribute value to be written DW-5
+ * @reserved: spec reserved DW-6,7
+ */
+struct utp_upiu_query {
+	u8 opcode;
+	u8 idn;
+	u8 index;
+	u8 selector;
+	u16 reserved_osf;
+	u16 length;
+	u32 value;
+	u32 reserved[2];
+};
+
+/**
  * struct utp_upiu_req - general upiu request structure
  * @header:UPIU header structure DW-0 to DW-2
  * @sc: fields structure for scsi command DW-3 to DW-7
+ * @qr: fields structure for query request DW-3 to DW-7
  */
 struct utp_upiu_req {
 	struct utp_upiu_header header;
-	struct utp_upiu_cmd sc;
+	union {
+		struct utp_upiu_cmd sc;
+		struct utp_upiu_query qr;
+	};
 };
 
 /**

@@ -187,10 +243,14 @@ struct utp_cmd_rsp {
  * struct utp_upiu_rsp - general upiu response structure
  * @header: UPIU header structure DW-0 to DW-2
  * @sr: fields structure for scsi command DW-3 to DW-12
+ * @qr: fields structure for query request DW-3 to DW-7
  */
 struct utp_upiu_rsp {
 	struct utp_upiu_header header;
-	struct utp_cmd_rsp sr;
+	union {
+		struct utp_cmd_rsp sr;
+		struct utp_upiu_query qr;
+	};
 };
 
 /**

@@ -223,4 +283,24 @@ struct utp_upiu_task_rsp {
 	u32 reserved[3];
 };
 
+/**
+ * struct ufs_query_req - parameters for building a query request
+ * @query_func: UPIU header query function
+ * @upiu_req: the query request data
+ */
+struct ufs_query_req {
+	u8 query_func;
+	struct utp_upiu_query upiu_req;
+};
+
+/**
+ * struct ufs_query_resp - UPIU QUERY
+ * @response: device response code
+ * @upiu_res: query response data
+ */
+struct ufs_query_res {
+	u8 response;
+	struct utp_upiu_query upiu_res;
+};
+
 #endif /* End of Header */
drivers/scsi/ufs/ufshcd.c +174 -1
index 3f482b6..96ccb28 100644
@@ -48,6 +48,14 @@
 /* Timeout after 30 msecs if NOP OUT hangs without response */
 #define NOP_OUT_TIMEOUT    30 /* msecs */
 
+/* Query request retries */
+#define QUERY_REQ_RETRIES 10
+/* Query request timeout */
+#define QUERY_REQ_TIMEOUT 30 /* msec */
+
+/* Expose the flag value from utp_upiu_query.value */
+#define MASK_QUERY_UPIU_FLAG_LOC 0xFF
+
 enum {
 	UFSHCD_MAX_CHANNEL	= 0,
 	UFSHCD_MAX_ID		= 1,

@@ -348,6 +356,63 @@ static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
 }
 
 /**
+ * ufshcd_query_to_cpu() - formats the buffer to native cpu endian
+ * @response: upiu query response to convert
+ */
+static inline void ufshcd_query_to_cpu(struct utp_upiu_query *response)
+{
+	response->length = be16_to_cpu(response->length);
+	response->value = be32_to_cpu(response->value);
+}
+
+/**
+ * ufshcd_query_to_be() - formats the buffer to big endian
+ * @request: upiu query request to convert
+ */
+static inline void ufshcd_query_to_be(struct utp_upiu_query *request)
+{
+	request->length = cpu_to_be16(request->length);
+	request->value = cpu_to_be32(request->value);
+}
+
+/**
+ * ufshcd_copy_query_response() - Copy the Query Response and the data
+ * descriptor
+ * @hba: per adapter instance
+ * @lrb - pointer to local reference block
+ */
+static
+void ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
+{
+	struct ufs_query_res *query_res = hba->dev_cmd.query.response;
+
+	/* Get the UPIU response */
+	if (query_res) {
+		query_res->response = ufshcd_get_rsp_upiu_result(
+			lrbp->ucd_rsp_ptr) >> UPIU_RSP_CODE_OFFSET;
+
+		memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr,
+			QUERY_OSF_SIZE);
+		ufshcd_query_to_cpu(&query_res->upiu_res);
+	}
+
+	/* Get the descriptor */
+	if (hba->dev_cmd.query.descriptor && lrbp->ucd_rsp_ptr->qr.opcode ==
+			UPIU_QUERY_OPCODE_READ_DESC) {
+		u8 *descp = (u8 *)&lrbp->ucd_rsp_ptr +
+				GENERAL_UPIU_REQUEST_SIZE;
+		u16 len;
+
+		/* data segment length */
+		len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2) &
+						MASK_QUERY_DATA_SEG_LEN;
+
+		memcpy(hba->dev_cmd.query.descriptor, descp,
+			min_t(u16, len, UPIU_HEADER_DATA_SEGMENT_MAX_SIZE));
+	}
+}
+
+/**
  * ufshcd_hba_capabilities - Read controller capabilities
  * @hba: per adapter instance
  */

@@ -629,6 +694,46 @@ void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32 upiu_flags)
 		(min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
 }
 
+/**
+ * ufshcd_prepare_utp_query_req_upiu() - fills the utp_transfer_req_desc,
+ * for query requsts
+ * @hba: UFS hba
+ * @lrbp: local reference block pointer
+ * @upiu_flags: flags
+ */
+static void ufshcd_prepare_utp_query_req_upiu(struct ufs_hba *hba,
+					struct ufshcd_lrb *lrbp,
+					u32 upiu_flags)
+{
+	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
+	u16 len = hba->dev_cmd.query.request->upiu_req.length;
+	u8 *descp = (u8 *)lrbp->ucd_req_ptr + GENERAL_UPIU_REQUEST_SIZE;
+
+	/* Query request header */
+	ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
+			UPIU_TRANSACTION_QUERY_REQ, upiu_flags,
+			lrbp->lun, lrbp->task_tag);
+	ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
+			0, hba->dev_cmd.query.request->query_func, 0, 0);
+
+	/* Data segment length */
+	ucd_req_ptr->header.dword_2 = UPIU_HEADER_DWORD(
+			0, 0, len >> 8, (u8)len);
+
+	/* Copy the Query Request buffer as is */
+	memcpy(&lrbp->ucd_req_ptr->qr, &hba->dev_cmd.query.request->upiu_req,
+			QUERY_OSF_SIZE);
+	ufshcd_query_to_be(&lrbp->ucd_req_ptr->qr);
+
+	/* Copy the Descriptor */
+	if ((hba->dev_cmd.query.descriptor != NULL) && (len > 0) &&
+		(hba->dev_cmd.query.request->upiu_req.opcode ==
+					UPIU_QUERY_OPCODE_WRITE_DESC)) {
+		memcpy(descp, hba->dev_cmd.query.descriptor,
+			min_t(u16, len, UPIU_HEADER_DATA_SEGMENT_MAX_SIZE));
+	}
+}
+
 static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
 {
 	struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;

@@ -663,7 +768,10 @@ static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 		break;
 	case UTP_CMD_TYPE_DEV_MANAGE:
 		ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
-		if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
+		if (hba->dev_cmd.type == DEV_CMD_TYPE_QUERY)
+			ufshcd_prepare_utp_query_req_upiu(
+					hba, lrbp, upiu_flags);
+		else if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
 			ufshcd_prepare_utp_nop_upiu(lrbp);
 		else
 			ret = -EINVAL;

@@ -831,6 +939,9 @@ ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 					__func__, resp);
 		}
 		break;
+	case UPIU_TRANSACTION_QUERY_RSP:
+		ufshcd_copy_query_response(hba, lrbp);
+		break;
 	case UPIU_TRANSACTION_REJECT_UPIU:
 		/* TODO: handle Reject UPIU Response */
 		err = -EPERM;

@@ -941,6 +1052,128 @@ out_put_tag:
 }
 
 /**
+ * ufshcd_query_request() - API for issuing query request to the device.
+ * @hba: ufs driver context
+ * @query: params for query request
+ * @descriptor: buffer for sending/receiving descriptor
+ * @retries: number of times to try executing the command
+ *
+ * All necessary fields for issuing a query and receiving its response
+ * are stored in the UFS hba struct. We can use this method since we know
+ * there is only one active query request or any device management command
+ * at all times.
+ */
+static int ufshcd_send_query_request(struct ufs_hba *hba,
+					struct ufs_query_req *query,
+					u8 *descriptor,
+					struct ufs_query_res *response)
+{
+	int ret;
+
+	BUG_ON(!hba);
+	if (!query || !response) {
+		dev_err(hba->dev,
+			"%s: NULL pointer query = %p, response = %p\n",
+			__func__, query, response);
+		return -EINVAL;
+	}
+
+	mutex_lock(&hba->dev_cmd.lock);
+	hba->dev_cmd.query.request = query;
+	hba->dev_cmd.query.response = response;
+	hba->dev_cmd.query.descriptor = descriptor;
+
+	ret = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY,
+					QUERY_REQ_TIMEOUT);
+
+	hba->dev_cmd.query.request = NULL;
+	hba->dev_cmd.query.response = NULL;
+	hba->dev_cmd.query.descriptor = NULL;
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	return ret;
+}
+
+/**
+ * ufshcd_query_flag() - Helper function for composing flag query requests
+ * hba: per-adapter instance
+ * query_opcode: flag query to perform
+ * idn: flag idn to access
+ * flag_res: the flag value after the query request completes
+ *
+ * Returns 0 for success, non-zero in case of failure
+ */
+static int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
+			enum flag_idn idn, bool *flag_res)
+{
+	struct ufs_query_req *query;
+	struct ufs_query_res *response;
+	int err = -ENOMEM;
+
+	query = kzalloc(sizeof(struct ufs_query_req), GFP_KERNEL);
+	if (!query) {
+		dev_err(hba->dev,
+			"%s: Failed allocating ufs_query_req instance\n",

drivers/scsi/ufs/ufshcd.c out_put_tag: · line 1126

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +10 -0
+			__func__);
+		goto out_no_mem;
+	}
+	response = kzalloc(sizeof(struct ufs_query_res), GFP_KERNEL);
+	if (!response) {
+		dev_err(hba->dev,
+			"%s: Failed allocating ufs_query_res instance\n",
+			__func__);
+		goto out_free_query;
+	}

Can't stack local variable be permitted for query and response instead of dynamic allocation?

Quoted 54 lines
drivers/scsi/ufs/ufshcd.c +50 -0
+
+	switch (opcode) {
+	case UPIU_QUERY_OPCODE_SET_FLAG:
+	case UPIU_QUERY_OPCODE_CLEAR_FLAG:
+	case UPIU_QUERY_OPCODE_TOGGLE_FLAG:
+		query->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+		break;
+	case UPIU_QUERY_OPCODE_READ_FLAG:
+		query->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+		if (!flag_res) {
+			/* No dummy reads */
+			dev_err(hba->dev, "%s: Invalid argument for read request\n",
+					__func__);
+			err = -EINVAL;
+			goto out;
+		}
+		break;
+	default:
+		dev_err(hba->dev,
+			"%s: Expected query flag opcode but got = %d\n",
+			__func__, opcode);
+		err = -EINVAL;
+		goto out;
+	}
+	query->upiu_req.opcode = opcode;
+	query->upiu_req.idn = idn;
+
+	/* Send query request */
+	err = ufshcd_send_query_request(hba, query, NULL, response);
+
+	if (err) {
+		dev_err(hba->dev,
+			"%s: Sending flag query for idn %d failed, err = %d\n",
+			__func__, idn, err);
+		goto out;
+	}
+
+	if (flag_res)
+		*flag_res = (response->upiu_res.value &
+				MASK_QUERY_UPIU_FLAG_LOC) & 0x1;
+
+out:
+	kfree(response);
+out_free_query:
+	kfree(query);
+out_no_mem:
+	return err;
+}
+
+/**
  * ufshcd_memory_alloc - allocate memory for host memory space data structures
  * @hba: per adapter instance
  *

drivers/scsi/ufs/ufshcd.c static int ufshcd_dme_link_startup(struct ufs_hba *hba) · line 1352

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +7 -0
@@ -1110,6 +1343,59 @@ static int ufshcd_dme_link_startup(struct ufs_hba *hba)
 }
 
 /**
+ * ufshcd_validate_device_init() - checks device readiness
+ * hba: per-adapter instance
+ *
+ * Set fDeviceInit flag, than, query the flag until the device clears the
+ * flag.
+ */
+static int ufshcd_validate_device_init(struct ufs_hba *hba)

As standard description, this function is for initialization completion. How about ufshcd_complete_dev_init for function name?

drivers/scsi/ufs/ufshcd.c static int ufshcd_dme_link_startup(struct ufs_hba *hba) · line 1360

Quoted 8 lines
drivers/scsi/ufs/ufshcd.c +8 -0
+{
+	int i, retries, err = 0;
+	bool flag_res = 0;
+
+	for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+		/* Set the fDeviceIntit flag */
+		err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
+					QUERY_FLAG_IDN_FDEVICEINIT, &flag_res);

There is no need to get flag_res in case set flag. Just passing NULL is good.

drivers/scsi/ufs/ufshcd.c static int ufshcd_dme_link_startup(struct ufs_hba *hba) · line 1373

Quoted 13 lines
drivers/scsi/ufs/ufshcd.c +13 -0
+		if (!err || err == -ETIMEDOUT)
+			break;
+		dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
+	}
+	if (err) {
+		dev_err(hba->dev,
+			"%s setting fDeviceInit flag failed with error %d\n",
+			__func__, err);
+		goto out;
+	}
+
+	/* poll for max. 100 iterations for fDeviceInit flag to clear */
+	for (i = 0; i < 100 && !err && flag_res; i++) {

In first ufshcd_query_flag, if flag_res is updated with '0', this loop can't be executed. Of course, we expect that flag_res has '1'.

drivers/scsi/ufs/ufshcd.c static int ufshcd_dme_link_startup(struct ufs_hba *hba) · line 1380

Quoted 7 lines
drivers/scsi/ufs/ufshcd.c +7 -0
+		retries = QUERY_REQ_RETRIES;
+		for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
+			err = ufshcd_query_flag(hba,
+					UPIU_QUERY_OPCODE_READ_FLAG,
+					QUERY_FLAG_IDN_FDEVICEINIT, &flag_res);
+			if (!err || err == -ETIMEDOUT)
+				break;

Normally, ufshcd_query_flag returns '0' to err while flag is not being cleared. If these routine is repeated, inner for-loop is just executed and go to outer loop. What is difference between two for-loop?

Thanks,
Seungwon Jeon

Quoted 92 lines
drivers/scsi/ufs/ufshcd.c +22 -0
+			dev_dbg(hba->dev, "%s: error %d retrying\n", __func__,
+					err);
+		}
+	}
+	if (err)
+		dev_err(hba->dev,
+			"%s reading fDeviceInit flag failed with error %d\n",
+			__func__, err);
+	else if (flag_res)
+		dev_err(hba->dev,
+			"%s fDeviceInit was not cleared by the device\n",
+			__func__);
+
+out:
+	return err;
+}
+
+/**
  * ufshcd_make_hba_operational - Make UFS controller operational
  * @hba: per adapter instance
  *

@@ -1962,6 +2248,10 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
 	if (ret)
 		goto out;
 
+	ret = ufshcd_validate_device_init(hba);
+	if (ret)
+		goto out;
+
 	scsi_scan_host(hba->host);
 out:
 	return;
drivers/scsi/ufs/ufshcd.h +14 -0
index c750a90..c6aeb6d 100644
@@ -70,6 +70,7 @@
 
 enum dev_cmd_type {
 	DEV_CMD_TYPE_NOP		= 0x0,
+	DEV_CMD_TYPE_QUERY		= 0x1,
 };
 
 /**

@@ -125,6 +126,18 @@ struct ufshcd_lrb {
 };
 
 /**
+ * struct ufs_query - holds relevent data structures for query request
+ * @request: request upiu and function
+ * @descriptor: buffer for sending/receiving descriptor
+ * @response: response upiu and response
+ */
+struct ufs_query {
+	struct ufs_query_req *request;
+	u8 *descriptor;
+	struct ufs_query_res *response;
+};
+
+/**
  * struct ufs_dev_cmd - all assosiated fields with device management commands
  * @type: device management command type - Query, NOP OUT
  * @lock: lock to allow one command at a time

@@ -136,6 +149,7 @@ struct ufs_dev_cmd {
 	struct mutex lock;
 	struct completion *complete;
 	wait_queue_head_t tag_wq;
+	struct ufs_query query;
 };
 
 /**
drivers/scsi/ufs/ufshci.h +1 -2
index d5c5f14..f1e1b74 100644
@@ -39,7 +39,7 @@
 enum {
 	TASK_REQ_UPIU_SIZE_DWORDS	= 8,
 	TASK_RSP_UPIU_SIZE_DWORDS	= 8,
-	ALIGNED_UPIU_SIZE		= 128,
+	ALIGNED_UPIU_SIZE		= 512,
 };
 
 /* UFSHCI Registers */
--

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