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alistair23-linux/drivers/mmc/core
Adrian Hunter dfe86cba76 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>
2010-08-12 08:43:30 -07:00
..
Kconfig mmc: add module parameter to set whether cards are assumed removable 2009-12-15 08:53:35 -08:00
Makefile mmc: Export internal host state through debugfs 2008-07-27 01:26:16 +02:00
bus.c mmc: implement SD-combo (IO+mem) support 2010-08-11 08:59:03 -07:00
bus.h mmc: use sysfs groups to handle conditional attributes 2008-03-22 17:02:20 -07:00
core.c mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
core.h mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
debugfs.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
host.c mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume 2010-08-11 08:59:03 -07:00
host.h mmc: add 'enable' and 'disable' methods to mmc host 2009-09-23 07:39:33 -07:00
mmc.c mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
mmc_ops.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mmc_ops.h mmc: add mmc card sleep and awake support 2009-09-23 07:39:33 -07:00
sd.c mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
sd.h mmc: split mmc_sd_init_card() 2010-08-11 08:59:02 -07:00
sd_ops.c mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
sd_ops.h mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
sdio.c sdio: allow non-standard SDIO cards 2010-08-11 08:59:04 -07:00
sdio_bus.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sdio_bus.h mmc: basic SDIO device model 2007-09-23 19:45:31 +02:00
sdio_cis.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sdio_cis.h sdio: split up common and function CIS parsing 2007-09-23 20:44:22 +02:00
sdio_io.c sdio: add new function for RAW (Read after Write) operation 2010-05-27 09:12:40 -07:00
sdio_irq.c sdio: give sdio irq thread a host specific name 2008-10-12 11:04:30 +02:00
sdio_ops.c sdio: recognize io card without powercycle 2010-03-12 15:52:28 -08:00
sdio_ops.h sdio: recognize io card without powercycle 2010-03-12 15:52:28 -08:00