3 Commits

Author	SHA1	Message	Date
Daniel Axtens	08c7dd1bd4	crypto: powerpc - Re-enable non-REFLECTed CRCs ... When CRC32c was included in the kernel, Anton ripped out the #ifdefs around reflected polynomials, because CRC32c is always reflected. However, not all CRCs use reflection so we'd like to make it optional. Restore the REFLECT parts from Anton's original CRC32 implementation (https://github.com/antonblanchard/crc32-vpmsum) That implementation is available under GPLv2+, so we're OK from a licensing point of view: https://github.com/antonblanchard/crc32-vpmsum/blob/master/LICENSE.TXT As CRC32c requires REFLECT, add that #define. Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>	2017-03-24 22:02:53 +08:00
Daniel Axtens	de696a2643	crypto: powerpc - Factor out the core CRC vpmsum algorithm ... The core nuts and bolts of the crc32c vpmsum algorithm will also work for a number of other CRC algorithms with different polynomials. Factor out the function into a new asm file. To handle multiple users of the function, a user simply provides constants, defines the name of their CRC function, and then #includes the core algorithm file. Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>	2017-03-24 22:02:52 +08:00
Anton Blanchard	6dd7a82cc5	crypto: powerpc - Add POWER8 optimised crc32c ... Use the vector polynomial multiply-sum instructions in POWER8 to speed up crc32c. This is just over 41x faster than the slice-by-8 method that it replaces. Measurements on a 4.1 GHz POWER8 show it sustaining 52 GiB/sec. A simple btrfs write performance test: dd if=/dev/zero of=/mnt/tmpfile bs=1M count=4096 sync is over 3.7x faster. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>	2016-07-05 23:05:19 +08:00