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authorKyungmin Park <kyungmin.park@samsung.com>2011-10-18 09:34:04 +0900
committerChris Ball <cjb@laptop.org>2011-10-26 16:32:27 -0400
commitb3bf915308ca2b50f3beec6cc824083870f0f4b5 (patch)
tree955978242b333e1388358b4b50b5f8f4a5abca04
parentd9ddd62943ee07a75d0428ffcf52f1a747a28c39 (diff)
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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>
-rw-r--r--drivers/mmc/card/block.c4
-rw-r--r--drivers/mmc/core/core.c14
-rw-r--r--drivers/mmc/core/mmc.c4
-rw-r--r--include/linux/mmc/card.h3
-rw-r--r--include/linux/mmc/core.h2
5 files changed, 26 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;
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 711c3f8bfabd..551378508784 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -80,6 +80,9 @@ struct mmc_ext_csd {
u8 raw_sec_feature_support;/* 231 */
u8 raw_trim_mult; /* 232 */
u8 raw_sectors[4]; /* 212 - 4 bytes */
+
+ unsigned int feature_support;
+#define MMC_DISCARD_FEATURE BIT(0) /* CMD38 feature */
};
struct sd_scr {
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 9585835cbc42..e918120235bd 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -146,6 +146,7 @@ extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
#define MMC_ERASE_ARG 0x00000000
#define MMC_SECURE_ERASE_ARG 0x80000000
#define MMC_TRIM_ARG 0x00000001
+#define MMC_DISCARD_ARG 0x00000003
#define MMC_SECURE_TRIM1_ARG 0x80000001
#define MMC_SECURE_TRIM2_ARG 0x80008000
@@ -156,6 +157,7 @@ extern int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
unsigned int arg);
extern int mmc_can_erase(struct mmc_card *card);
extern int mmc_can_trim(struct mmc_card *card);
+extern int mmc_can_discard(struct mmc_card *card);
extern int mmc_can_sanitize(struct mmc_card *card);
extern int mmc_can_secure_erase_trim(struct mmc_card *card);
extern int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,