mmc: support HPI send command

This patch is added sending function for HPI command.

HPI command is defined in eMMC4.41.
We didn't use this feature..but maybe we need to use HPI command for eMMC4.5 feature. (If we use HPI command, it's useful for increasing performance and decreasing latency.)

This patch is based on Chuanxiao's patch which one of many patches related with HPI sent to mailing..

Signed-off-by Jaehoon Chung <[email protected]>

Signed-off-by Kyungmin Park <[email protected]>

Signed-off-by Chuanxiao Dong <[email protected]>

CC Hanumath Prasad <[email protected]>

---
v4 :
- change pr_info/pr_debug instead of printk()
- remove unnecessary parameter.
v3 :
- Change response type R1 instead of R1b.(using STOP_TRANSMMISION)
- Check card status with SEND_STATUS after sending HPI

v2 : add error checking (when send hpi, card is out of prg-state)

---
 drivers/mmc/core/core.c    |   58 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/mmc/core/mmc.c     |   37 +++++++++++++++++++++++++++-
 drivers/mmc/core/mmc_ops.c |   31 +++++++++++++++++++++++
 drivers/mmc/core/mmc_ops.h |    1 +
 include/linux/mmc/card.h   |    4 +++
 include/linux/mmc/core.h   |    1 +
 include/linux/mmc/mmc.h    |    3 ++
 7 files changed, 134 insertions(+), 1 deletions(-)

drivers/mmc/core/core.c +58 -0

index eb3069d..06fd77c 100644
@@ -360,6 +360,64 @@ void mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
 EXPORT_SYMBOL(mmc_wait_for_req);
 
 /**
+ *	mmc_interrupt_hpi - Issue for High priority Interrupt
+ *	@card: the MMC card associated with the HPI transfer
+ *
+ *	Issued High Priority Interrupt, and check for card status
+ *	util out-of prg-state.
+ */
+int mmc_interrupt_hpi(struct mmc_card *card)
+{
+	int err;
+	u32 status;
+
+	BUG_ON(!card);
+
+	if (!card->ext_csd.hpi_en) {
+		pr_info("Didn't set HPI enable bit!\n");
+		return 1;
+	}
+
+	mmc_claim_host(card->host);
+	err = mmc_send_status(card, &status);
+	if (err) {
+		pr_err("Didn't get card status!\n");
+		goto out;
+	}
+
+	/*
+	 * If Card status is prg-state, can send HPI command
+	 */
+	if (R1_CURRENT_STATE(status) == R1_STATE_PRG) {
+		do {
+			/*
+			 * Actually, didn't be ensure that
+			 * HPI command is running exactly.
+			 * So, need to resend HPI until out of prg-state.
+			 * then check the card status with SEND_STATUS.
+			 * If timeout error is occured(when send hpi command),
+			 * that means already out of prg-state.
+			 */
+			err = mmc_send_hpi_cmd(card, &status);
+			if (err)
+				pr_debug("abort HPI (%d error)", err);
+			else
+				pr_debug("HPI success!!!\n");
+
+			err = mmc_send_status(card, &status);
+			if (err)
+				break;
+		} while (R1_CURRENT_STATE(status) == R1_STATE_PRG);
+	} else
+		pr_debug("Already out of prg-state!!\n");
+
+out:
+	mmc_release_host(card->host);
+	return err;
+}
+EXPORT_SYMBOL(mmc_interrupt_hpi);
+
+/**
  *	mmc_wait_for_cmd - start a command and wait for completion
  *	@host: MMC host to start command
  *	@cmd: MMC command to start

drivers/mmc/core/mmc.c +36 -1

index 5700b1c..ef312c9 100644
@@ -402,8 +402,26 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
 			ext_csd[EXT_CSD_TRIM_MULT];
 	}
 
-	if (card->ext_csd.rev >= 5)
+	if (card->ext_csd.rev >= 5) {
+		/* check whether the eMMC card support HPI */
+		if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x1) {
+			card->ext_csd.hpi = 1;
+			if (ext_csd[EXT_CSD_HPI_FEATURES] & 0x2)
+				card->ext_csd.hpi_cmd =
+						MMC_STOP_TRANSMISSION;
+			else
+				card->ext_csd.hpi_cmd =
+						MMC_SEND_STATUS;
+
+			/*
+			 * Indicate the maximum timeout to close
+			 * a command interrupted by HPI
+			 */
+			card->ext_csd.out_of_int_time =
+				ext_csd[EXT_CSD_OUT_OF_INTERRUPT_TIME] * 10;
+		}
 		card->ext_csd.rel_param = ext_csd[EXT_CSD_WR_REL_PARAM];
+	}
 
 	if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
 		card->erased_byte = 0xFF;

@@ -726,6 +744,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * Enable HPI feature (if supported)
+	 */
+	if (card->ext_csd.hpi) {
+		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			EXT_CSD_HPI_MGMT, 1, 0);
+		if (err && err != -EBADMSG)
+			goto free_card;
+
+		if (err) {
+			printk(KERN_WARNING "%s: Enabling HPI failed\n",
+				mmc_hostname(card->host));
+			err = 0;
+		} else
+			card->ext_csd.hpi_en = 1;
+	}
+
+	/*
 	 * Compute bus speed.
 	 */
 	max_dtr = (unsigned int)-1;

drivers/mmc/core/mmc_ops.c +31 -0

index 770c3d0..4706400 100644
@@ -547,3 +547,34 @@ int mmc_bus_test(struct mmc_card *card, u8 bus_width)
 	err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
 	return err;
 }
+
+int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status)
+{
+	struct mmc_command cmd;
+	unsigned int opcode;
+	unsigned int flags;
+	int err;
+
+	opcode = card->ext_csd.hpi_cmd;
+	if (opcode == MMC_STOP_TRANSMISSION)
+		flags = MMC_RSP_R1 | MMC_CMD_AC;
+	else if (opcode == MMC_SEND_STATUS)
+		flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+	cmd.opcode = opcode;
+	cmd.arg = card->rca << 16 | 1;
+	cmd.flags = flags;
+	cmd.cmd_timeout_ms = card->ext_csd.out_of_int_time;
+
+	err = mmc_wait_for_cmd(card->host, &cmd, 0);
+	if (err) {
+		printk(KERN_DEBUG "error %d interrupting operation"
+			"HPI command response  %#x\n",
+				err, cmd.resp[0]);
+		return err;
+	}
+	if (status)
+		*status = cmd.resp[0];
+	return 0;
+}

drivers/mmc/core/mmc_ops.h +1 -0

index 9276946..2a6e0db 100644
@@ -17,6 +17,7 @@ int mmc_deselect_cards(struct mmc_host *host);
 int mmc_go_idle(struct mmc_host *host);
 int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr);
 int mmc_all_send_cid(struct mmc_host *host, u32 *cid);
+int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status);
 int mmc_set_relative_addr(struct mmc_card *card);
 int mmc_send_csd(struct mmc_card *card, u32 *csd);
 int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd);

include/linux/mmc/card.h +4 -0

index b460fc2..411054d 100644
@@ -64,10 +64,14 @@ struct mmc_ext_csd {
 	unsigned long long	enhanced_area_offset;	/* Units: Byte */
 	unsigned int		enhanced_area_size;	/* Units: KB */
 	unsigned int		boot_size;		/* in bytes */
+	bool			hpi_en;			/* HPI enablebit */
+	bool			hpi;			/* HPI support bit */
+	unsigned int		hpi_cmd;		/* cmd used as HPI */
 	u8			raw_partition_support;	/* 160 */
 	u8			raw_erased_mem_count;	/* 181 */
 	u8			raw_ext_csd_structure;	/* 194 */
 	u8			raw_card_type;		/* 196 */
+	u8			out_of_int_time;	/* 198 */
 	u8			raw_s_a_timeout;		/* 217 */
 	u8			raw_hc_erase_gap_size;	/* 221 */
 	u8			raw_erase_timeout_mult;	/* 223 */

include/linux/mmc/core.h +1 -0

index b8b1b7a..dca3c08 100644
@@ -136,6 +136,7 @@ struct mmc_async_req;
 
 extern struct mmc_async_req *mmc_start_req(struct mmc_host *,
 					   struct mmc_async_req *, int *);
+extern int mmc_interrupt_hpi(struct mmc_card *);
 extern void mmc_wait_for_req(struct mmc_host *, struct mmc_request *);
 extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int);
 extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);

include/linux/mmc/mmc.h +3 -1

index 5a794cb..e16c776 100644
@@ -272,6 +272,7 @@ struct _mmc_csd {
 
 #define EXT_CSD_PARTITION_ATTRIBUTE	156	/* R/W */
 #define EXT_CSD_PARTITION_SUPPORT	160	/* RO */
+#define EXT_CSD_HPI_MGMT		161	/* R/W */
 #define EXT_CSD_WR_REL_PARAM		166	/* RO */
 #define EXT_CSD_ERASE_GROUP_DEF		175	/* R/W */
 #define EXT_CSD_PART_CONFIG		179	/* R/W */

@@ -281,6 +282,7 @@ struct _mmc_csd {
 #define EXT_CSD_REV			192	/* RO */
 #define EXT_CSD_STRUCTURE		194	/* RO */
 #define EXT_CSD_CARD_TYPE		196	/* RO */
+#define EXT_CSD_OUT_OF_INTERRUPT_TIME	198	/* RO */
 #define EXT_CSD_PART_SWITCH_TIME        199     /* RO */
 #define EXT_CSD_SEC_CNT			212	/* RO, 4 bytes */
 #define EXT_CSD_S_A_TIMEOUT		217	/* RO */

@@ -293,6 +295,7 @@ struct _mmc_csd {
 #define EXT_CSD_SEC_ERASE_MULT		230	/* RO */
 #define EXT_CSD_SEC_FEATURE_SUPPORT	231	/* RO */
 #define EXT_CSD_TRIM_MULT		232	/* RO */
+#define EXT_CSD_HPI_FEATURES		503	/* RO */
 
 /*
  * EXT_CSD field definitions
--

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This feature is also used in eMMC4.41. So i want to know your opinion. (In eMMC4.5, i known this feature is important)
If need more modification, i will do. if not, i want to merge this feature.

Hi Jaehoon,

Quoted 3 lines · Jaehoon Chung

This feature is also used in eMMC4.41. So i want to know your opinion. (In eMMC4.5, i known this feature is important)
If need more modification, i will do. if not, i want to merge this feature.

I don't have any eMMC 4.5 devices -- the patch looks plausible, but it would be nice to get a Tested-by from someone else who's tested it on different devices to you and wants to see it merged.

Thanks,

- Chris.