* 'for-linus' of git://neil.brown.name/md:
async_tx: fix asynchronous raid6 recovery for ddf layouts
async_pq: rename scribble page
async_pq: kill a stray dma_map() call and other cleanups
md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning
raid6/async_tx: handle holes in block list in async_syndrome_val
md/async: don't pass a memory pointer as a page pointer.
md: Fix handling of raid5 array which is being reshaped to fewer devices.
md: fix problems with RAID6 calculations for DDF.
md/raid456: downlevel multicore operations to raid_run_ops
md: drivers/md/unroll.pl replaced with awk analog
md: remove clumsy usage of do_sync_mapping_range from bitmap code
md: raid1/raid10: handle allocation errors during array setup.
md/raid5: initialize conf->device_lock earlier
md/raid1/raid10: add a cond_resched
Revert "md: do not progress the resync process if the stripe was blocked"
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>
The global scribble page is used as a temporary destination buffer when
disabling the P or Q result is requested. The local scribble buffer
contains memory for performing address conversions. Rename the global
variable to avoid confusion.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
- update the kernel doc for async_syndrome to indicate what NULL in the
source list means
- whitespace fixups
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
async_syndrome_val check the P and Q blocks used for RAID6
calculations.
With DDF raid6, some of the data blocks might be NULL, so
this needs to be handled in the same way that async_gen_syndrome
handles it.
As async_syndrome_val calls async_xor, also enhance async_xor
to detect and skip NULL blocks in the list.
Signed-off-by: NeilBrown <neilb@suse.de>
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>
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
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>
Testing on x86_64 with NDISKS=255 yields:
do_IRQ: modprobe near stack overflow (cur:ffff88007d19c000,sp:ffff88007d19c128)
...and eventually
general protection fault: 0000 [#1]
Moving the scribble buffers off the stack allows the test to complete
successfully.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (102 commits)
crypto: sha-s390 - Fix warnings in import function
crypto: vmac - New hash algorithm for intel_txt support
crypto: api - Do not displace newly registered algorithms
crypto: ansi_cprng - Fix module initialization
crypto: xcbc - Fix alignment calculation of xcbc_tfm_ctx
crypto: fips - Depend on ansi_cprng
crypto: blkcipher - Do not use eseqiv on stream ciphers
crypto: ctr - Use chainiv on raw counter mode
Revert crypto: fips - Select CPRNG
crypto: rng - Fix typo
crypto: talitos - add support for 36 bit addressing
crypto: talitos - align locks on cache lines
crypto: talitos - simplify hmac data size calculation
crypto: mv_cesa - Add support for Orion5X crypto engine
crypto: cryptd - Add support to access underlaying shash
crypto: gcm - Use GHASH digest algorithm
crypto: ghash - Add GHASH digest algorithm for GCM
crypto: authenc - Convert to ahash
crypto: api - Fix aligned ctx helper
crypto: hmac - Prehash ipad/opad
...
Some engines have transfer size and address alignment restrictions. Add
a per-operation alignment property to struct dma_device that the async
routines and dmatest can use to check alignment capabilities.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Channel switching is problematic for some dmaengine drivers as the
architecture precludes separating the ->prep from ->submit. In these
cases the driver can select ASYNC_TX_DISABLE_CHANNEL_SWITCH to modify
the async_tx allocator to only return channels that support all of the
required asynchronous operations.
For example MD_RAID456=y selects support for asynchronous xor, xor
validate, pq, pq validate, and memcpy. When
ASYNC_TX_DISABLE_CHANNEL_SWITCH=y any channel with all these
capabilities is marked DMA_ASYNC_TX allowing async_tx_find_channel() to
quickly locate compatible channels with the guarantee that dependency
chains will remain on one channel. When
ASYNC_TX_DISABLE_CHANNEL_SWITCH=n async_tx_find_channel() may select
channels that lead to operation chains that need to cross channel
boundaries using the async_tx channel switch capability.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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>
We have a mechanism where newly registered algorithms of a higher
priority can displace existing instances that use a different
implementation of the same algorithm with a lower priority.
Unfortunately the same mechanism can cause a newly registered
algorithm to displace itself if it depends on an existing version
of the same algorithm.
This patch fixes this by keeping all algorithms that the newly
reigstered algorithm depends on, thus protecting them from being
removed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Port drivers/md/raid6test/test.c to use the async raid6 recovery
routines. This is meant as a unit test for raid6 acceleration drivers. In
addition to the 16-drive test case this implements tests for the 4-disk and
5-disk special cases (dma devices can not generically handle less than 2
sources), and adds a test for the D+Q case.
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>
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>
[ Based on an original patch by Yuri Tikhonov ]
This adds support for doing asynchronous GF multiplication by adding
two additional functions to the async_tx API:
async_gen_syndrome() does simultaneous XOR and Galois field
multiplication of sources.
async_syndrome_val() validates the given source buffers against known P
and Q values.
When a request is made to run async_pq against more than the hardware
maximum number of supported sources we need to reuse the previous
generated P and Q values as sources into the next operation. Care must
be taken to remove Q from P' and P from Q'. For example to perform a 5
source pq op with hardware that only supports 4 sources at a time the
following approach is taken:
p, q = PQ(src0, src1, src2, src3, COEF({01}, {02}, {04}, {08}))
p', q' = PQ(p, q, q, src4, COEF({00}, {01}, {00}, {10}))
p' = p + q + q + src4 = p + src4
q' = {00}*p + {01}*q + {00}*q + {10}*src4 = q + {10}*src4
Note: 4 is the minimum acceptable maxpq otherwise we punt to
synchronous-software path.
The DMA_PREP_CONTINUE flag indicates to the driver to reuse p and q as
sources (in the above manner) and fill the remaining slots up to maxpq
with the new sources/coefficients.
Note1: Some devices have native support for P+Q continuation and can skip
this extra work. Devices with this capability can advertise it with
dma_set_maxpq. It is up to each driver how to handle the
DMA_PREP_CONTINUE flag.
Note2: The api supports disabling the generation of P when generating Q,
this is ignored by the synchronous path but is implemented by some dma
devices to save unnecessary writes. In this case the continuation
algorithm is simplified to only reuse Q as a source.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.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>
We currently walk the parent chain when waiting for a given tx to
complete however this walk may race with the driver cleanup routine.
The routines in async_raid6_recov.c may fall back to the synchronous
path at any point so we need to be prepared to call async_tx_quiesce()
(which calls dma_wait_for_async_tx). To remove the ->parent walk we
guarantee that every time a dependency is attached ->issue_pending() is
invoked, then we can simply poll the initial descriptor until
completion.
This also allows for a lighter weight 'issue pending' implementation as
there is no longer a requirement to iterate through all the channels'
->issue_pending() routines as long as operations have been submitted in
an ordered chain. async_tx_issue_pending() is added for this case.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
