From: Saugata Das <[email protected]> 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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
