mmc: block: Allow disabling 512B sector size emulation

This patch adds support for large sector size of 4KB by disabling
emulation.  This patch passes eMMC DATA_SECTOR_SIZE as the logical
block size during mmc_blk_alloc_req.

In order to use this patch for 4KB sector size, ensure that
USE_NATIVE_SECTOR is enabled, partition table is 4KB sector size
aligned and file system block and sector size are 4KB multiples.

Signed-off-by: Saugata Das <saugata.das@linaro.org>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 19 insertions, 2 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 91cda7551a60..dd2d374dcc7a 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1284,7 +1284,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
         int ret = 1, disable_multi = 0, retry = 0, type;
         enum mmc_blk_status status;
         struct mmc_queue_req *mq_rq;
-        struct request *req;
+        struct request *req = rqc;
         struct mmc_async_req *areq;
 
         if (!rqc && !mq->mqrq_prev->req)
@@ -1292,6 +1292,16 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
 
         do {
                 if (rqc) {
+                        /*
+                         * When 4KB native sector is enabled, only 8 blocks
+                         * multiple read or write is allowed
+                         */
+                        if ((brq->data.blocks & 0x07) &&
+                            (card->ext_csd.data_sector_size == 4096)) {
+                                pr_err("%s: Transfer size is not 4KB sector size aligned\n",
+                                        req->rq_disk->disk_name);
+                                goto cmd_abort;
+                        }
                         mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
                         areq = &mq->mqrq_cur->mmc_active;
                 } else
@@ -1539,7 +1549,12 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
         snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
                  "mmcblk%d%s", md->name_idx, subname ? subname : "");
 
-        blk_queue_logical_block_size(md->queue.queue, 512);
+        if (mmc_card_mmc(card))
+                blk_queue_logical_block_size(md->queue.queue,
+                                             card->ext_csd.data_sector_size);
+        else
+                blk_queue_logical_block_size(md->queue.queue, 512);
+
         set_capacity(md->disk, size);
 
         if (mmc_host_cmd23(card->host)) {
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 2f0e11c9fd67..2d4a4b746750 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -516,6 +516,8 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 } else {
                         card->ext_csd.data_tag_unit_size = 0;
                 }
+        } else {
+                card->ext_csd.data_sector_size = 512;
         }
 
 out: