kernel/linux.git/arch/powerpc/lib/string.S, branch v6.12.80

powerpc: replace #include with #include

2023-08-16T13:54:48+00:00

Commit ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost") deprecated , which is now a wrapper of . Replace #include with #include . After all the lines are converted, and will be removed. Signed-off-by: Masahiro Yamada [mpe: Fixup selftests that stub asm/export.h] Signed-off-by: Michael Ellerman Link: https://msgid.link/20230806150954.394189-2-masahiroy@kernel.org

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/lib: optimise PPC32 memcmp

2018-06-03T14:39:21+00:00

At the time being, memcmp() compares two chunks of memory byte per byte. This patch optimises the comparison by comparing word by word. On the same way as commit 15c2d45d17418 ("powerpc: Add 64bit optimised memcmp"), this patch moves memcmp() into a dedicated file named memcmp_32.S A small benchmark performed on an 8xx comparing two chuncks of 512 bytes performed 100000 times gives: Before : 5852274 TB ticks After: 1488638 TB ticks This is almost 4 times faster Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: optimise 32 bits __clear_user()

2018-06-03T14:39:21+00:00

Rewrite clear_user() on the same principle as memset(0), making use of dcbz to clear complete cache lines. This code is a copy/paste of memset(), with some modifications in order to retrieve remaining number of bytes to be cleared, as it needs to be returned in case of error. On the same way as done on PPC64 in commit 17968fbbd19f1 ("powerpc: 64bit optimised __clear_user"), the patch moves __clear_user() into a dedicated file string_32.S On a MPC885, throughput is almost doubled: Before: ~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 18.990779 seconds, 52.7MB/s After: ~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 9.611468 seconds, 104.0MB/s On a MPC8321, throughput is multiplied by 2.12: Before: root@vgoippro:~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 6.844352 seconds, 146.1MB/s After: root@vgoippro:~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 3.218854 seconds, 310.7MB/s Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: Adjust .balign inside string functions for PPC32

2018-06-03T14:39:19+00:00

commit 87a156fb18fe1 ("Align hot loops of some string functions") degraded the performance of string functions by adding useless nops A simple benchmark on an 8xx calling 100000x a memchr() that matches the first byte runs in 41668 TB ticks before this patch and in 35986 TB ticks after this patch. So this gives an improvement of approx 10% Another benchmark doing the same with a memchr() matching the 128th byte runs in 1011365 TB ticks before this patch and 1005682 TB ticks after this patch, so regardless on the number of loops, removing those useless nops improves the test by 5683 TB ticks. Fixes: 87a156fb18fe1 ("Align hot loops of some string functions") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: EX_TABLE macro for exception tables

2016-11-14T00:11:51+00:00

This macro is taken from s390, and allows more flexibility in changing exception table format. mpe: Put it in ppc_asm.h and only define one version using stringinfy_in_c(). Add some empty definitions and headers to keep the selftests happy. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman

ppc: move exports to definitions

2016-08-08T03:50:09+00:00

Signed-off-by: Al Viro

powerpc: Align hot loops of some string functions

2016-06-14T03:58:25+00:00

Align the hot loops in our assembly implementation of strncpy(), strncmp() and memchr(). Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

powerpc: Remove assembly versions of strcpy, strcat, strlen and strcmp

2016-06-14T03:58:25+00:00

A number of our assembly implementations of string functions do not align their hot loops. I was going to align them manually, but I realised that they are are almost instruction for instruction identical to what gcc produces, with the advantage that gcc does align them. In light of that, let's just remove the assembly versions. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

powerpc: Add 64bit optimised memcmp

2015-01-23T03:02:55+00:00

I noticed ksm spending quite a lot of time in memcmp on a large KVM box. The current memcmp loop is very unoptimised - byte at a time compares with no loop unrolling. We can do much much better. Optimise the loop in a few ways: - Unroll the byte at a time loop - For large (at least 32 byte) comparisons that are also 8 byte aligned, use an unrolled modulo scheduled loop using 8 byte loads. This is similar to our glibc memcmp. A simple microbenchmark testing 10000000 iterations of an 8192 byte memcmp was used to measure the performance: baseline: 29.93 s modified: 1.70 s Just over 17x faster. v2: Incorporated some suggestions from Segher: - Use andi. instead of rdlicl. - Convert bdnzt eq, to bdnz. It's just duplicating the earlier compare and was a relic from a previous version. - Don't use cr5, we have plans to use that CR field for fast local atomics. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman