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scsi: ufs: add support for query requests

PATCH Superseded Dolev Raviv 1 participant 1 message Apr 25, 2013

Subsystems (2)

v3 of 5 Superseded Latest is v5 →

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PATCH v3 1/1 scsi: ufs: add support for query requests

Add support for sending UFS query requests through tagged command queuing. This design allows queuing query requests in any open slot along with other SCSI commands. In this way there is no need to save a slot in the requests queue and decrease its size.

A query request is posing to a SCSI command to use native flow. But unlike normal SCSI command flow, the data and response fields are filled in UFS host data structure instead of passing as arguments while queuing into SCSI mlqueue (mid-layer SCSI queue, the requests from this queue are submitted to the device queue). As per specification only one query request is allowed to be processed by device. Hence a mutex lock for protecting data and response fields (hba->query.request and hba->query.response) needs to be held while query request is in progress.

The API for submitting a query request is ufs_query_request() in ufshcd.c. This function is responsible for:
1. Obtaining the SCSI device from the host
2. Keeping the query mutex to prevent multiple queries
3. Storing the required data for sending a query request in ufs_hba
4. Queuing a SCSI vendor specific command to trigger a query request in the UFS driver.

The callers of ufs_query_request() are expected to fill the query command data fields and are to provide an allocated response field for the driver to fill response fields after request completion.

The request and response upiu is extended in a union to enable using the same data structure, both for command upiu and query request upiu.

The query request flow is separated from the scsi command flow in:
1. Preparing the request
2. Validating response (error) codes
3. Copying data (only used for descriptor read/write query requests)
4. Copying response/sense

Data error can't be handled in the scsi command native flow. Hence, we pass the code as without a change back to the submitting layer.

UPIU (UFS Protocol Information Unit) size is increased to 512 bytes from 128. The UPIU header and the transaction specific fields (SCSI command or Query Request OSF - Op-code Specific Fields) are 32 bytes together, the rest is used to transfer extra request data (such as descriptor in query requests). In order to accommodate the largest descriptor in the UFS spec (256 bytes) we need to increase the UPIU size.

---
changes for v3:
- Reworked validating response UPIU
- Removed redundant NULL pointer checks
changes for v2:
- Moved ufs_query_request to ufshcd.c and removed ufs_core.c
- Addressed Santosh's comments

drivers/scsi/ufs/ufs.h +114 -8
index 139bc06..086ff03 100644
@@ -36,10 +36,20 @@
 #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 QUERY_OSF_SIZE			((GENERAL_UPIU_REQUEST_SIZE) - \
+					(sizeof(struct utp_upiu_header)))
+#define UFS_QUERY_RESERVED_SCSI_CMD 0xCC
+#define UFS_QUERY_CMD_SIZE 10
 
 #define UPIU_HEADER_DWORD(byte3, byte2, byte1, byte0)\
-			((byte3 << 24) | (byte2 << 16) |\
+			cpu_to_be32((byte3 << 24) | (byte2 << 16) |\
 			 (byte1 << 8) | (byte0))
 
 /*
@@ -62,7 +72,7 @@ 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 */
@@ -73,6 +83,7 @@ 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 */
@@ -90,6 +101,12 @@ enum {
 	UPIU_TASK_ATTR_ACA	= 0x03,
 };
 
+/* UPIU Query request function */
+enum {
+	UPIU_QUERY_FUNC_STANDARD_READ_REQUEST = 0x01,
+	UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST = 0x81,
+};
+
 /* UTP QUERY Transaction Specific Fields OpCode */
 enum {
 	UPIU_QUERY_OPCODE_NOP		= 0x0,
@@ -103,6 +120,21 @@ 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,
@@ -110,10 +142,17 @@ 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,
 	MASK_RSP_UPIU_RESULT	= 0xFFFF,
+	MASK_QUERY_DATA_SEG_LEN	= 0xFFFF,
 };
 
 /* Task management service response */
@@ -138,26 +177,59 @@ 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_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-6
+ * @reserved: spec reserved DW-7,8
+ */
+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
+ * @qr: fields structure for query request
+ */
+struct utp_upiu_req {
+	struct utp_upiu_header header;
+	union {
+		struct utp_upiu_cmd sc;
+		struct utp_upiu_query qr;
+	};
+};
+
+/**
+ * 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 +237,20 @@ struct utp_upiu_rsp {
 };
 
 /**
+ * struct utp_upiu_rsp - general upiu response structure
+ * @header: UPIU header structure DW-0 to DW-2
+ * @sc: fields structure for scsi command
+ * @qr: fields structure for query request
+ */
+struct utp_upiu_rsp {
+	struct utp_upiu_header header;
+	union {
+		struct utp_cmd_rsp sc;
+		struct utp_upiu_query qr;
+	};
+};
+
+/**
  * struct utp_upiu_task_req - Task request UPIU structure
  * @header - UPIU header structure DW0 to DW-2
  * @input_param1: Input parameter 1 DW-3
@@ -194,4 +280,24 @@ 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 +357 -91

539 lines not on this page · raw message

drivers/scsi/ufs/ufshcd.h +20 -2
index 6b99a42..e6ca79f 100644
@@ -60,6 +60,7 @@
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_eh.h>
+#include <scsi/scsi_device.h>
 
 #include "ufs.h"
 #include "ufshci.h"
@@ -88,7 +89,7 @@ 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
@@ -101,7 +102,7 @@ struct uic_command {
  */
 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;
 
@@ -115,6 +116,19 @@ struct ufshcd_lrb {
 	unsigned int lun;
 };
 
+/**
+ * struct ufs_query - keeps the query request information
+ * @request: request upiu and function
+ * @descriptor: buffer for sending/receiving descriptor
+ * @response: response upiu and response
+ * @mutex: lock to allow one query at a time
+ */
+struct ufs_query {
+	struct ufs_query_req *request;
+	u8 *descriptor;
+	struct ufs_query_res *response;
+	struct mutex mutex;
+};
 
 /**
  * struct ufs_hba - per adapter private structure
@@ -143,6 +157,7 @@ struct ufshcd_lrb {
  * @uic_workq: Work queue for UIC completion handling
  * @feh_workq: Work queue for fatal controller error handling
  * @errors: HBA errors
+ * @query: query request information
  */
 struct ufs_hba {
 	void __iomem *mmio_base;
@@ -184,6 +199,9 @@ struct ufs_hba {
 
 	/* HBA Errors */
 	u32 errors;
+
+	/* Query Request */
+	struct ufs_query query;
 };
 
 int ufshcd_init(struct device *, struct ufs_hba ** , void __iomem * ,
drivers/scsi/ufs/ufshci.h +1 -1
index 0c16484..4a86247 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 · 4 lines
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