mmc: add erase, secure erase, trim and secure trim operations

SD/MMC cards tend to support an erase operation.  In addition, eMMC v4.4
cards can support secure erase, trim and secure trim operations that are
all variants of the basic erase command.

SD/MMC device attributes "erase_size" and "preferred_erase_size" have been
added.

"erase_size" is the minimum size, in bytes, of an erase operation.  For
MMC, "erase_size" is the erase group size reported by the card.  Note that
"erase_size" does not apply to trim or secure trim operations where the
minimum size is always one 512 byte sector.  For SD, "erase_size" is 512
if the card is block-addressed, 0 otherwise.

SD/MMC cards can erase an arbitrarily large area up to and
including the whole card.  When erasing a large area it may
be desirable to do it in smaller chunks for three reasons:

    1. A single erase command will make all other I/O on the card
       wait.  This is not a problem if the whole card is being erased, but
       erasing one partition will make I/O for another partition on the
       same card wait for the duration of the erase - which could be a
       several minutes.

    2. To be able to inform the user of erase progress.

    3. The erase timeout becomes too large to be very useful.
       Because the erase timeout contains a margin which is multiplied by
       the size of the erase area, the value can end up being several
       minutes for large areas.

"erase_size" is not the most efficient unit to erase (especially for SD
where it is just one sector), hence "preferred_erase_size" provides a good
chunk size for erasing large areas.

For MMC, "preferred_erase_size" is the high-capacity erase size if a card
specifies one, otherwise it is based on the capacity of the card.

For SD, "preferred_erase_size" is the allocation unit size specified by
the card.

"preferred_erase_size" is in bytes.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 7 deletions

diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 52ce98866287..dd11ae51fb68 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -251,13 +251,21 @@ struct _mmc_csd {
  * EXT_CSD fields
  */
 
-#define EXT_CSD_BUS_WIDTH       183     /* R/W */
-#define EXT_CSD_HS_TIMING       185     /* R/W */
-#define EXT_CSD_CARD_TYPE       196     /* RO */
-#define EXT_CSD_STRUCTURE       194     /* RO */
-#define EXT_CSD_REV             192     /* RO */
-#define EXT_CSD_SEC_CNT         212     /* RO, 4 bytes */
-#define EXT_CSD_S_A_TIMEOUT     217
+#define EXT_CSD_ERASE_GROUP_DEF         175     /* R/W */
+#define EXT_CSD_ERASED_MEM_CONT         181     /* RO */
+#define EXT_CSD_BUS_WIDTH               183     /* R/W */
+#define EXT_CSD_HS_TIMING               185     /* R/W */
+#define EXT_CSD_REV                     192     /* RO */
+#define EXT_CSD_STRUCTURE               194     /* RO */
+#define EXT_CSD_CARD_TYPE               196     /* RO */
+#define EXT_CSD_SEC_CNT                 212     /* RO, 4 bytes */
+#define EXT_CSD_S_A_TIMEOUT             217     /* RO */
+#define EXT_CSD_ERASE_TIMEOUT_MULT      223     /* RO */
+#define EXT_CSD_HC_ERASE_GRP_SIZE       224     /* RO */
+#define EXT_CSD_SEC_TRIM_MULT           229     /* RO */
+#define EXT_CSD_SEC_ERASE_MULT          230     /* RO */
+#define EXT_CSD_SEC_FEATURE_SUPPORT     231     /* RO */
+#define EXT_CSD_TRIM_MULT               232     /* RO */
 
 /*
  * EXT_CSD field definitions
@@ -275,6 +283,10 @@ struct _mmc_csd {
 #define EXT_CSD_BUS_WIDTH_4     1       /* Card is in 4 bit mode */
 #define EXT_CSD_BUS_WIDTH_8     2       /* Card is in 8 bit mode */
 
+#define EXT_CSD_SEC_ER_EN       BIT(0)
+#define EXT_CSD_SEC_BD_BLK_EN   BIT(2)
+#define EXT_CSD_SEC_GB_CL_EN    BIT(4)
+
 /*
  * MMC_SWITCH access modes
  */