Reuse the existing crc32 code to stamp out a crc32c implementation.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add slicing-by-8 algorithm to the existing slicing-by-4 algorithm. This
consists of:
- extend largest BITS size from 32 to 64
- extend tables from tab[4][256] to up to tab[8][256]
- Add code for inner loop.
[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
crc32.c provides a choice of one of several algorithms for computing the
LSB and LSB versions of the CRC32 checksum based on the parameters
CRC_LE_BITS and CRC_BE_BITS.
In the original version the values 1, 2, 4 and 8 respectively selected
versions of the alrogithm that computed the crc 1, 2, 4 and 32 bits as a
time.
This patch series adds a new version that computes the CRC 64 bits at a
time. To make things easier to understand the parameter has been
reinterpreted to actually stand for the number of bits processed in each
step of the algorithm so that the old value 8 has been replaced with the
value 32.
This also allows us to add in a widely used crc algorithm that computes
the crc 8 bits at a time called the Sarwate algorithm.
[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Misc cleanup of lib/crc32.c and related files.
- remove unnecessary header files.
- straighten out some convoluted ifdef's
- rewrite some references to 2 dimensional arrays as 1 dimensional
arrays to make them correct. I.e. replace tab[i] with tab[0][i].
- a few trivial whitespace changes
- fix a warning in gen_crc32tables.c caused by a mismatch in the type of
the pointer passed to output table. Since the table is only used at
kernel compile time, it is simpler to make the table big enough to hold
the largest column size used. One cannot make the column size smaller
in output_table because it has to be used by both the le and be tables
and they can have different column sizes.
[djwong@us.ibm.com: Minor changelog tweaks]
Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com>
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Precompute more crc32 values(0xcc00, 0xcc0000 and 0xcc000000) into tables.
This increases the table size from 1KB to 4KB but the performance benfit
makes it worth it:
28% faster on MPC8321, 266 MHz
2x faster on Core 2 Duo, 3.1GHz
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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!
