linux-toradex.git/lib/crc32.c, branch v3.14-rc6

lib: crc32: reduce number of cases for crc32{, c}_combine

2013-11-04T20:27:08+00:00

We can safely reduce the number of test cases by a tenth.
There is no particular need to run as many as we're running
now for crc32{,c}_combine, that gives us still ~8000 tests
we're doing if people run kernels with crc selftests enabled
which is perfectly fine.

Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

lib: crc32: conditionally resched when running testcases

2013-11-04T20:27:08+00:00

Fengguang reports that when crc32 selftests are running on startup, on
some e.g. 32bit systems, we can get a CPU stall like "INFO: rcu_sched
self-detected stall on CPU { 0} (t=2101 jiffies g=4294967081 c=4294967080
q=41)". As this is not intended, add a cond_resched() at the end of a
test case to fix it. Introduced by efba721f63 ("lib: crc32: add test cases
for crc32{, c}_combine routines").

Reported-by: Fengguang Wu 
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

lib: crc32: add test cases for crc32{, c}_combine routines

2013-11-04T04:04:56+00:00

We already have 100 test cases for crcs itself, so split the test
buffer with a-prio known checksums, and test crc of two blocks
against crc of the whole block for the same results.

Output/result with CONFIG_CRC32_SELFTEST=y:

  [    2.687095] crc32: CRC_LE_BITS = 64, CRC_BE BITS = 64
  [    2.687097] crc32: self tests passed, processed 225944 bytes in 278177 nsec
  [    2.687383] crc32c: CRC_LE_BITS = 64
  [    2.687385] crc32c: self tests passed, processed 225944 bytes in 141708 nsec
  [    7.336771] crc32_combine: 113072 self tests passed
  [   12.050479] crc32c_combine: 113072 self tests passed
  [   17.633089] alg: No test for crc32 (crc32-pclmul)

Signed-off-by: Daniel Borkmann 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller

lib: crc32: add functionality to combine two crc32{, c}s in GF(2)

2013-11-04T04:04:56+00:00

This patch adds a combinator to merge two or more crc32{,c}s
into a new one. This is useful for checksum computations of
fragmented skbs that use crc32/crc32c as checksums.

The arithmetics for combining both in the GF(2) was taken and
slightly modified from zlib. Only passing two crcs is insufficient
as two crcs and the length of the second piece is needed for
merging. The code is made generic, so that only polynomials
need to be passed for crc32_le resp. crc32c_le.

Signed-off-by: Daniel Borkmann 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller

lib: crc32: clean up spacing in test cases

2013-11-04T04:04:56+00:00

This is nothing more but a whitepace cleanup, as 80 chars is not a
hard but soft limit, and otherwise makes the test cases array really
look ugly. So fix it up.

Signed-off-by: Daniel Borkmann 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller

lib/crc32: update the comments of crc32_{be,le}_generic()

2013-09-11T22:58:38+00:00

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Gu Zheng 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sections: fix const sections for crc32 table

2012-10-05T18:04:46+00:00

Fix the const sections for the code generated by crc32 table.  There's
no ro version of the cacheline aligned section, so we cannot put in
const data without a conflict Just don't make the crc tables const for
now.

[ak@linux.intel.com: some fixes and new description]
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Joe Mario 
Signed-off-by: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/crc32.c: fix unused variables warnings

2012-07-31T00:25:17+00:00

Variables t4, t5, t6 and t7 are only used when CRC_LE_BITS != 32.  Fix
the following compilation warnings:

  lib/crc32.c: In function 'crc32_body':
  lib/crc32.c:77:55: warning: unused variable 't7'
  lib/crc32.c:77:41: warning: unused variable 't6'
  lib/crc32.c:77:27: warning: unused variable 't5'
  lib/crc32.c:77:13: warning: unused variable 't4'

Signed-off-by: Thiago Rafael Becker 
Cc: "Darrick J. Wong" 
Cc: Bob Pearson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

crc32: add self-test code for crc32c

2012-03-23T23:58:38+00:00

Add self-test code for crc32c.

Signed-off-by: Darrick J. Wong 
Cc: Bob Pearson 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

crc32: bolt on crc32c

2012-03-23T23:58:38+00:00

Reuse the existing crc32 code to stamp out a crc32c implementation.

Signed-off-by: Darrick J. Wong 
Cc: Herbert Xu 
Cc: Bob Pearson 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds