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authorKyungmin Park <kyungmin.park@samsung.com>2011-10-18 04:34:04 +0400
committerChris Ball <cjb@laptop.org>2011-10-27 00:32:27 +0400
commitb3bf915308ca2b50f3beec6cc824083870f0f4b5 (patch)
tree955978242b333e1388358b4b50b5f8f4a5abca04 /drivers/mmc
parentd9ddd62943ee07a75d0428ffcf52f1a747a28c39 (diff)
downloadlinux-b3bf915308ca2b50f3beec6cc824083870f0f4b5.tar.xz
mmc: core: new discard feature support at eMMC v4.5
MMC v4.5 supports the DISCARD feature (CMD38). It's different from trim and there's no check bit. Currently it's only supported at v4.5. Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/card/block.c4
-rw-r--r--drivers/mmc/core/core.c14
-rw-r--r--drivers/mmc/core/mmc.c4
3 files changed, 21 insertions, 1 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index e85816e1634a..370472797fff 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -756,7 +756,9 @@ static int mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
from = blk_rq_pos(req);
nr = blk_rq_sectors(req);
- if (mmc_can_trim(card))
+ if (mmc_can_discard(card))
+ arg = MMC_DISCARD_ARG;
+ else if (mmc_can_trim(card))
arg = MMC_TRIM_ARG;
else
arg = MMC_ERASE_ARG;
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index d9836e5a4e59..772de2cdfd1d 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1709,10 +1709,24 @@ int mmc_can_trim(struct mmc_card *card)
{
if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN)
return 1;
+ if (mmc_can_discard(card))
+ return 1;
return 0;
}
EXPORT_SYMBOL(mmc_can_trim);
+int mmc_can_discard(struct mmc_card *card)
+{
+ /*
+ * As there's no way to detect the discard support bit at v4.5
+ * use the s/w feature support filed.
+ */
+ if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL(mmc_can_discard);
+
int mmc_can_sanitize(struct mmc_card *card)
{
if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f8ea9387d75c..54088768776c 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -452,6 +452,10 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
card->ext_csd.rst_n_function = ext_csd[EXT_CSD_RST_N_FUNCTION];
}
+ /* eMMC v4.5 or later */
+ if (card->ext_csd.rev >= 6)
+ card->ext_csd.feature_support |= MMC_DISCARD_FEATURE;
+
card->ext_csd.raw_erased_mem_count = ext_csd[EXT_CSD_ERASED_MEM_CONT];
if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
card->erased_byte = 0xFF;