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path: root/crypto/async_tx/async_raid6_recov.c
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2011-10-31crypto: add module.h to those files that are explicitly using itPaul Gortmaker
Part of the include cleanups means that the implicit inclusion of module.h via device.h is going away. So fix things up in advance. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2010-05-05raid6: fix recovery performance regressionDan Williams
The raid6 recovery code should immediately drop back to the optimized synchronous path when a p+q dma resource is not available. Otherwise we run the non-optimized/multi-pass async code in sync mode. Verified with raid6test (NDISKS=255) Applies to kernels >= 2.6.32. Cc: <stable@kernel.org> Acked-by: NeilBrown <neilb@suse.de> Reported-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-19async_tx: fix asynchronous raid6 recovery for ddf layoutsDan Williams
The raid6 recovery code currently requires special handling of the 4-disk and 5-disk recovery scenarios for the native layout. Quoting from commit 0a82a623: 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. The ddf layout presents disks=6 and disks=7 to the recovery code in these situations. Instead of looking at the number of disks count the number of non-zero sources in the list and call the special case code when the number of non-failed sources is 0 or 1. [neilb@suse.de: replace 'ddf' flag with counting good sources] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-10-16md/async: don't pass a memory pointer as a page pointer.NeilBrown
md/raid6 passes a list of 'struct page *' to the async_tx routines, which then either DMA map them for offload, or take the page_address for CPU based calculations. For RAID6 we sometime leave 'blanks' in the list of pages. For CPU based calcs, we want to treat theses as a page of zeros. For offloaded calculations, we simply don't pass a page to the hardware. Currently the 'blanks' are encoded as a pointer to raid6_empty_zero_page. This is a 4096 byte memory region, not a 'struct page'. This is mostly handled correctly but is rather ugly. So change the code to pass and expect a NULL pointer for the blanks. When taking page_address of a page, we need to check for a NULL and in that case use raid6_empty_zero_page. Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-21async_tx/raid6: add missing dma_unmap calls to the async fail caseDan Williams
If we are unable to offload async_mult() or async_sum_product(), then unmap the buffers before falling through to the synchronous path. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08dmaengine: add fence supportDan Williams
Some engines optimize operation by reading ahead in the descriptor chain such that descriptor2 may start execution before descriptor1 completes. If descriptor2 depends on the result from descriptor1 then a fence is required (on descriptor2) to disable this optimization. The async_tx api could implicitly identify dependencies via the 'depend_tx' parameter, but that would constrain cases where the dependency chain only specifies a completion order rather than a data dependency. So, provide an ASYNC_TX_FENCE to explicitly identify data dependencies. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29async_tx: add support for asynchronous RAID6 recovery operationsDan Williams
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>