kernel-hacking-2024-linux-s.../crypto/async_tx
Dan Williams 0a82a6239b async_tx: add support for asynchronous RAID6 recovery operations
async_raid6_2data_recov() recovers two data disk failures

 async_raid6_datap_recov() recovers a data disk and the P disk

These routines are a port of the synchronous versions found in
drivers/md/raid6recov.c.  The primary difference is breaking out the xor
operations into separate calls to async_xor.  Two helper routines are
introduced to perform scalar multiplication where needed.
async_sum_product() multiplies two sources by scalar coefficients and
then sums (xor) the result.  async_mult() simply multiplies a single
source by a scalar.

This implemention also includes, in contrast to the original
synchronous-only code, special case handling for the 4-disk and 5-disk
array cases.  In these situations the default N-disk algorithm will
present 0-source or 1-source operations to dma devices.  To cover for
dma devices where the minimum source count is 2 we implement 4-disk and
5-disk handling in the recovery code.

[ Impact: asynchronous raid6 recovery routines for 2data and datap cases ]

Cc: Yuri Tikhonov <yur@emcraft.com>
Cc: Ilya Yanok <yanok@emcraft.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:27 -07:00
..
async_memcpy.c async_tx: kill needless module_{init|exit} 2009-08-29 19:09:26 -07:00
async_memset.c async_tx: kill needless module_{init|exit} 2009-08-29 19:09:26 -07:00
async_pq.c async_tx: add support for asynchronous GF multiplication 2009-08-29 19:09:27 -07:00
async_raid6_recov.c async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00
async_tx.c async_tx: remove walk of tx->parent chain in dma_wait_for_async_tx 2009-08-29 19:09:27 -07:00
async_xor.c async_tx: add support for asynchronous GF multiplication 2009-08-29 19:09:27 -07:00
Kconfig async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00
Makefile async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00