From 4265900e0be653f5b78baf2816857ef57cf1332f Mon Sep 17 00:00:00 2001 From: Saugata Das Date: Wed, 21 Dec 2011 13:09:17 +0530 Subject: mmc: MMC-4.5 Data Tag Support 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 Tested-by: Venkatraman S Signed-off-by: Chris Ball --- drivers/mmc/card/block.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'drivers/mmc/card') diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index e5a3c7b6ded..f2020d37c65 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -1080,6 +1080,7 @@ 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 @@ -1155,6 +1156,16 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq, if (do_rel_wr) 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). @@ -1173,13 +1184,13 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq, * We'll avoid using CMD23-bounded multiblock writes for * these, while retaining features like reliable writes. */ - - if ((md->flags & MMC_BLK_CMD23) && - mmc_op_multi(brq->cmd.opcode) && - (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) { + if ((md->flags & MMC_BLK_CMD23) && mmc_op_multi(brq->cmd.opcode) && + (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; } -- cgit v1.2.3