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>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index e85816e..3704727 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -756,7 +756,9 @@
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 d9836e5..772de2c 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1709,10 +1709,24 @@
{
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 f8ea938..5408876 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -452,6 +452,10 @@
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;