30 Aug, 2009
2 commits
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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
Cc: Ilya Yanok
Cc: H. Peter Anvin
Cc: David Woodhouse
Reviewed-by: Andre Noll
Acked-by: Maciej Sosnowski
Signed-off-by: Dan Williams -
[ 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}*src4Note: 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
Cc: David Woodhouse
Signed-off-by: Yuri Tikhonov
Signed-off-by: Ilya Yanok
Reviewed-by: Andre Noll
Acked-by: Maciej Sosnowski
Signed-off-by: Dan Williams
04 Jun, 2009
3 commits
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async_xor() needs space to perform dma and page address conversions. In
most cases the code can simply reuse the struct page * array because the
size of the native pointer matches the size of a dma/page address. In
order to support archs where sizeof(dma_addr_t) is larger than
sizeof(struct page *), or to preserve the input parameters, we utilize a
memory region passed in by the caller.Since the code is now prepared to handle the case where it cannot
perform address conversions on the stack, we no longer need the
!HIGHMEM64G dependency in drivers/dma/Kconfig.[ Impact: don't clobber input buffers for address conversions ]
Reviewed-by: Andre Noll
Acked-by: Maciej Sosnowski
Signed-off-by: Dan Williams -
Prepare the api for the arrival of a new parameter, 'scribble'. This
will allow callers to identify scratchpad memory for dma address or page
address conversions. As this adds yet another parameter, take this
opportunity to convert the common submission parameters (flags,
dependency, callback, and callback argument) into an object that is
passed by reference.Also, take this opportunity to fix up the kerneldoc and add notes about
the relevant ASYNC_TX_* flags for each routine.[ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]
Signed-off-by: Andre Noll
Acked-by: Maciej Sosnowski
Signed-off-by: Dan Williams -
In support of inter-channel chaining async_tx utilizes an ack flag to
gate whether a dependent operation can be chained to another. While the
flag is not set the chain can be considered open for appending. Setting
the ack flag closes the chain and flags the descriptor for garbage
collection. The ASYNC_TX_DEP_ACK flag essentially means "close the
chain after adding this dependency". Since each operation can only have
one child the api now implicitly sets the ack flag at dependency
submission time. This removes an unnecessary management burden from
clients of the api.[ Impact: clean up and enforce one dependency per operation ]
Reviewed-by: Andre Noll
Acked-by: Maciej Sosnowski
Signed-off-by: Dan Williams
09 Apr, 2009
1 commit
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'zero_sum' does not properly describe the operation of generating parity
and checking that it validates against an existing buffer. Change the
name of the operation to 'val' (for 'validate'). This is in
anticipation of the p+q case where it is a requirement to identify the
target parity buffers separately from the source buffers, because the
target parity buffers will not have corresponding pq coefficients.Reviewed-by: Andre Noll
Acked-by: Maciej Sosnowski
Signed-off-by: Dan Williams
06 Jan, 2009
1 commit
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"Wouldn't it be better if the dmaengine layer made sure it didn't pass
the same channel several times to a client?I mean, you seem concerned that the memcpy() API should be transparent
and easy to use, but the whole registration interface is just
ridiculously complicated..."
- HaavardThe dmaengine and async_tx registration/allocation interface is indeed
needlessly complicated. This redesign has the following goals:1/ Simplify reference counting: dma channels are not something one would
expect to be hotplugged, it should be an exceptional event handled by
drivers not something clients should be mandated to handle in a
callback. The common case channel removal event is 'rmmod ',
which for simplicity should be disallowed if the channel is in use.
2/ Add an interface for requesting exclusive access to a channel
suitable to device-to-memory users.
3/ Convert all memory-to-memory users over to a common allocator, the goal
here is to not have competing channel allocation schemes. The only
competition should be between device-to-memory exclusive allocations and
the memory-to-memory usage case where channels are shared between
multiple "clients".Cc: Haavard Skinnemoen
Cc: Neil Brown
Cc: Jeff Garzik
Reviewed-by: Andrew Morton
Signed-off-by: Dan Williams
11 Jan, 2008
1 commit
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This patch updates the list of transforms we support and clarifies that
the Block Ciphers interface in fact supports all ciphers including stream
ciphers.It also removes the obsolete Configuration Notes section and adds the
linux-crypto mailing list as the primary bug reporting address.Finally it documents the fact that setkey should only be called from
user context.Signed-off-by: Herbert Xu
25 Sep, 2007
1 commit
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Changes in v2:
* cleanups from Randy and ShannonReviewed-by: Randy Dunlap
Reviewed-by: Shannon Nelson
Signed-off-by: Dan Williams
09 May, 2007
1 commit
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Convert files within the Documentation directory to UTF-8.
Adrian Bunk:
small additional fixesSigned-off-by: John Anthony Kazos Jr.
Signed-off-by: Adrian Bunk
21 Mar, 2007
1 commit
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there is a tiny bug in Documentation/crypto/api-intro.txt.
The file has the following example code:struct scatterlist sg[2];
[...]
if (crypto_hash_digest(&desc, &sg, 2, result))which does not match the declaration of crypto_hash_digest() in
include/linux/crypto.h.(static inline int crypto_hash_digest(struct hash_desc *desc,
struct scatterlist *sg, unsigned int nbytes, u8 *out)The code in the example passes the address of a pointer (an array actually) as
the second argument, while the function expects the pointer itself.I have attached a patch to fix this.
Signed-off-by: Herbert Xu
07 Feb, 2007
1 commit
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This patch adds the developer of Camellia cipher algorithm.
Signed-off-by: Noriaki TAKAMIYA
Signed-off-by: Herbert Xu
21 Sep, 2006
1 commit
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This patch updates the documentation to reflect the switch from digest
to hash. It also replaces notes about emailing James Morris to refer
to me instead.Signed-off-by: Herbert Xu
11 Sep, 2005
1 commit
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The attached patch fixes the following spelling errors in Documentation/
- double "the"
- Several misspellings of function/functionality
- infomation
- memeory
- Recieved
- wether
and possibly others which I forgot ;-)
Trailing whitespaces on the same line as the typo are also deleted.Signed-off-by: Tobias Klauser
Signed-off-by: Domen Puncer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Sep, 2005
1 commit
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The XTEA implementation was incorrect due to a misinterpretation of
operator precedence. Because of the wide-spread nature of this
error, the erroneous implementation will be kept, albeit under the
new name of XETA.Signed-off-by: Aaron Grothe
Signed-off-by: Herbert Xu
Signed-off-by: David S. Miller
17 Apr, 2005
1 commit
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Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.Let it rip!
