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, 20 insertions, 0 deletions

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 4d893eaf8174..6b7525099e56 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -31,6 +31,7 @@ struct mmc_csd {
 	unsigned int		tacc_ns;
 	unsigned int		r2w_factor;
 	unsigned int		max_dtr;
+	unsigned int		erase_size;		/* In sectors */
 	unsigned int		read_blkbits;
 	unsigned int		write_blkbits;
 	unsigned int		capacity;
@@ -42,9 +43,16 @@ struct mmc_csd {
 
 struct mmc_ext_csd {
 	u8			rev;
+	u8			erase_group_def;
+	u8			sec_feature_support;
 	unsigned int		sa_timeout;		/* Units: 100ns */
 	unsigned int		hs_max_dtr;
 	unsigned int		sectors;
+	unsigned int		hc_erase_size;		/* In sectors */
+	unsigned int		hc_erase_timeout;	/* In milliseconds */
+	unsigned int		sec_trim_mult;	/* Secure trim multiplier  */
+	unsigned int		sec_erase_mult;	/* Secure erase multiplier */
+	unsigned int		trim_timeout;		/* In milliseconds */
 };
 
 struct sd_scr {
@@ -54,6 +62,12 @@ struct sd_scr {
 #define SD_SCR_BUS_WIDTH_4	(1<<2)
 };
 
+struct sd_ssr {
+	unsigned int		au;			/* In sectors */
+	unsigned int		erase_timeout;		/* In milliseconds */
+	unsigned int		erase_offset;		/* In milliseconds */
+};
+
 struct sd_switch_caps {
 	unsigned int		hs_max_dtr;
 };
@@ -106,6 +120,11 @@ struct mmc_card {
 #define MMC_QUIRK_NONSTD_SDIO	(1<<2)		/* non-standard SDIO card attached */
 						/* (missing CIA registers) */
 
+	unsigned int		erase_size;	/* erase size in sectors */
+ 	unsigned int		erase_shift;	/* if erase unit is power 2 */
+ 	unsigned int		pref_erase;	/* in sectors */
+ 	u8			erased_byte;	/* value of erased bytes */
+
 	u32			raw_cid[4];	/* raw card CID */
 	u32			raw_csd[4];	/* raw card CSD */
 	u32			raw_scr[2];	/* raw card SCR */
@@ -113,6 +132,7 @@ struct mmc_card {
 	struct mmc_csd		csd;		/* card specific */
 	struct mmc_ext_csd	ext_csd;	/* mmc v4 extended card specific */
 	struct sd_scr		scr;		/* extra SD information */
+	struct sd_ssr		ssr;		/* yet more SD information */
 	struct sd_switch_caps	sw_caps;	/* switch (CMD6) caps */
 
 	unsigned int		sdio_funcs;	/* number of SDIO functions */