This introduces crc_t10dif_update() which enables to calculate CRC
for a block which straddles multiple SG elements by calling multiple
times.  This also converts crc_t10dif() to use crc_t10dif_update() as
they are almost same.

(remove extra function call in crc_t10dif() and crc_t10dif_update -
 Tim + Herbert)
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: target-devel@vger.kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The T10 Protection Information format is also used by some devices that
do not go through the SCSI layer (virtual block devices, NVMe). Relocate
the relevant functions to a block layer library that can be used without
involving SCSI.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

This patch reinstates commits
	67822649
	39761214
	0b95a7f8
	31d93962
	2d31e518

Now that module softdeps are in the kernel we can use that to resolve
the boot issue which cause the revert.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This reverts commits
    67822649
    39761214
    0b95a7f8
    31d93962
    2d31e518

Unfortunately this change broke boot on some systems that used an
initrd which does not include the newly created crct10dif modules.
As these modules are required by sd_mod under certain configurations
this is a serious problem.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

When CRC T10 DIF is calculated using the crypto transform framework, we
wrap the crc_t10dif function call to utilize it.  This allows us to
take advantage of any accelerated CRC T10 DIF transform that is
plugged into the crypto framework.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

The SCSI Block Protocol uses this 16-bit CRC to verify the integrity
of each data sector.  crc_t10dif() is used by sd_dif.c when performing
I/O to or from disks formatted with protection information.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>