From: Saugata Das <saugata.das@xxxxxxxxxx>
MMC-4.5 data tag feature will be used to store the file system meta-data in the
tagged region of eMMC. This will improve the write and subsequent read transfer
time for the meta data.
Signed-off-by: Saugata Das <saugata.das@xxxxxxxxxx>
---
drivers/mmc/card/block.c | 17 +++++++++++++++--
drivers/mmc/core/mmc.c | 14 ++++++++++++++
include/linux/mmc/card.h | 2 ++
include/linux/mmc/mmc.h | 3 +++
4 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index a1cb21f..af3b6c3 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -995,6 +995,7 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
struct mmc_blk_request *brq = &mqrq->brq;
struct request *req = mqrq->req;
struct mmc_blk_data *md = mq->data;
+ bool do_data_tag;
/*
* Reliable writes are used to implement Forced Unit Access and
@@ -1071,6 +1072,16 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
mmc_apply_rel_rw(brq, card, req);
/*
+ * Data tag is used only during writing meta data to speed
+ * up write and any subsequent read of this meta data
+ */
+ do_data_tag = (card->ext_csd.data_tag_unit_size) &&
+ (req->cmd_flags & REQ_META) &&
+ (rq_data_dir(req) == WRITE) &&
+ ((brq->data.blocks * brq->data.blksz) >=
+ card->ext_csd.data_tag_unit_size) ;
+
+ /*
* Pre-defined multi-block transfers are preferable to
* open ended-ones (and necessary for reliable writes).
* However, it is not sufficient to just send CMD23,
@@ -1091,10 +1102,12 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
if ((md->flags & MMC_BLK_CMD23) &&
mmc_op_multi(brq->cmd.opcode) &&
- (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) {
+ (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23) ||
+ do_data_tag)) {
brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
brq->sbc.arg = brq->data.blocks |
- (do_rel_wr ? (1 << 31) : 0);
+ (do_rel_wr ? (1 << 31) : 0) |
+ (do_data_tag ? (1 << 29) : 0);
brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
brq->mrq.sbc = &brq->sbc;
}
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index dbf421a..244049b 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -488,6 +488,20 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
ext_csd[EXT_CSD_CACHE_SIZE + 1] << 8 |
ext_csd[EXT_CSD_CACHE_SIZE + 2] << 16 |
ext_csd[EXT_CSD_CACHE_SIZE + 3] << 24;
+
+ if (ext_csd[EXT_CSD_DATA_SECTOR_SIZE] == 1)
+ card->ext_csd.data_sector_size = 4096;
+ else
+ card->ext_csd.data_sector_size = 512;
+
+ if ((ext_csd[EXT_CSD_DATA_TAG_SUPPORT] & 1) &&
+ (ext_csd[EXT_CSD_TAG_UNIT_SIZE] <= 8)) {
+ card->ext_csd.data_tag_unit_size =
+ ((unsigned int) 1 << ext_csd[EXT_CSD_TAG_UNIT_SIZE]) *
+ (card->ext_csd.data_sector_size);
+ } else {
+ card->ext_csd.data_tag_unit_size = 0;
+ }
}
out:
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 415f2db..a55668d 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -71,6 +71,8 @@ struct mmc_ext_csd {
bool hpi_en; /* HPI enablebit */
bool hpi; /* HPI support bit */
unsigned int hpi_cmd; /* cmd used as HPI */
+ unsigned int data_sector_size; /* 512Bytes or 4KB */
+ unsigned int data_tag_unit_size; /* DATA TAG UNIT size */
u8 raw_partition_support; /* 160 */
u8 raw_erased_mem_count; /* 181 */
u8 raw_ext_csd_structure; /* 194 */
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 0e71356..e076f7f 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -273,6 +273,7 @@ struct _mmc_csd {
#define EXT_CSD_FLUSH_CACHE 32 /* W */
#define EXT_CSD_CACHE_CTRL 33 /* R/W */
#define EXT_CSD_POWER_OFF_NOTIFICATION 34 /* R/W */
+#define EXT_CSD_DATA_SECTOR_SIZE 61 /* R */
#define EXT_CSD_GP_SIZE_MULT 143 /* R/W */
#define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */
#define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
@@ -313,6 +314,8 @@ struct _mmc_csd {
#define EXT_CSD_POWER_OFF_LONG_TIME 247 /* RO */
#define EXT_CSD_GENERIC_CMD6_TIME 248 /* RO */
#define EXT_CSD_CACHE_SIZE 249 /* RO, 4 bytes */
+#define EXT_CSD_TAG_UNIT_SIZE 498 /* RO */
+#define EXT_CSD_DATA_TAG_SUPPORT 499 /* RO */
#define EXT_CSD_HPI_FEATURES 503 /* RO */
/*
--
1.7.4.3
--
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