Commit graph

3 commits

Author SHA1 Message Date
Tanzir Hasan
66a5c40f60 kernel.h: removed REPEAT_BYTE from kernel.h
This patch creates wordpart.h and includes it in asm/word-at-a-time.h
for all architectures. WORD_AT_A_TIME_CONSTANTS depends on kernel.h
because of REPEAT_BYTE. Moving this to another header and including it
where necessary allows us to not include the bloated kernel.h. Making
this implicit dependency on REPEAT_BYTE explicit allows for later
improvements in the lib/string.c inclusion list.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Tanzir Hasan <tanzirh@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20231226-libstringheader-v6-1-80aa08c7652c@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-01 09:47:59 -08:00
Heiko Carstens
802ba53eef s390: add support for DCACHE_WORD_ACCESS
Implement load_unaligned_zeropad() and enable DCACHE_WORD_ACCESS to
speed up string operations in fs/dcache.c and fs/namei.c.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-10-16 13:04:09 +02:00
Heiko Carstens
76292d7243 s390: provide word-at-a-time implementation
Provide an s390 specific word-at-a-time implementation. Compared to the
generic variant the generated code for has_zero() is slightly
better. However find_zero() is much simpler since it reuses the result
of __fls() aka flogr() and now comes without any conditional branches,
while the generic variant has three of them.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-10-16 13:04:09 +02:00