glibc/sysdeps/unix/sysv/linux/aarch64/cpu-features.c

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/* Initialize CPU feature data. AArch64 version.
This file is part of the GNU C Library.
Copyright (C) 2017-2020 Free Software Foundation, Inc.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
Prefer https to http for gnu.org and fsf.org URLs Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
<https://www.gnu.org/licenses/>. */
#include <cpu-features.h>
#include <sys/auxv.h>
#include <elf/dl-hwcaps.h>
aarch64: Optimized memset for falkor The generic memset reads dczid_el0 on every memset. This has a significant impact on falkor for a range of sizes because reading dczid_el0 is slow. The DZP bit in the dczid_el0 register does not change dynamically, so it is safe to read once during program startup. With this patch dczid_el0 is read once during startup and zva_size is cached. This is used to invoke the falkor-specific memset; the generic memset routine remains unchanged. The gains due to this are significant for falkor, with run time reductions as high as 48%. Here's a sample from the falkor tests: Function: memset Variant: walk simple_memset __memset_falkor __memset_generic ===================================================================== length=256, char=0: 139.96 (-698.28%) 9.07 ( 48.26%) 17.53 length=257, char=0: 140.50 (-699.03%) 9.53 ( 45.80%) 17.58 length=258, char=0: 140.96 (-703.95%) 9.58 ( 45.36%) 17.53 length=259, char=0: 141.56 (-705.16%) 9.53 ( 45.79%) 17.58 length=260, char=0: 142.15 (-710.76%) 9.57 ( 45.39%) 17.53 length=261, char=0: 142.50 (-710.39%) 9.53 ( 45.78%) 17.58 length=262, char=0: 142.97 (-715.09%) 9.57 ( 45.42%) 17.54 length=263, char=0: 143.51 (-716.18%) 9.53 ( 45.80%) 17.58 length=264, char=0: 143.93 (-720.55%) 9.58 ( 45.39%) 17.54 length=265, char=0: 144.56 (-722.07%) 9.53 ( 45.80%) 17.59 length=266, char=0: 144.98 (-726.42%) 9.58 ( 45.42%) 17.54 length=267, char=0: 145.53 (-727.53%) 9.53 ( 45.80%) 17.59 length=268, char=0: 146.25 (-731.81%) 9.53 ( 45.79%) 17.58 length=269, char=0: 146.52 (-735.39%) 9.53 ( 45.66%) 17.54 length=270, char=0: 146.97 (-735.81%) 9.53 ( 45.80%) 17.58 length=271, char=0: 147.54 (-741.08%) 9.58 ( 45.38%) 17.54 length=512, char=0: 268.26 (-1307.85%) 12.06 ( 36.71%) 19.05 length=513, char=0: 268.73 (-1273.89%) 13.56 ( 30.68%) 19.56 length=514, char=0: 269.31 (-1276.89%) 13.56 ( 30.68%) 19.56 length=515, char=0: 269.73 (-1279.05%) 13.56 ( 30.68%) 19.56 length=516, char=0: 270.34 (-1282.24%) 13.56 ( 30.67%) 19.56 length=517, char=0: 270.83 (-1284.71%) 13.56 ( 30.66%) 19.56 length=518, char=0: 271.20 (-1286.54%) 13.56 ( 30.67%) 19.56 length=519, char=0: 271.67 (-1288.67%) 13.65 ( 30.24%) 19.56 length=520, char=0: 272.14 (-1291.04%) 13.65 ( 30.22%) 19.56 length=521, char=0: 272.66 (-1293.69%) 13.65 ( 30.23%) 19.56 length=522, char=0: 273.14 (-1296.13%) 13.65 ( 30.20%) 19.56 length=523, char=0: 273.64 (-1298.75%) 13.65 ( 30.23%) 19.56 length=524, char=0: 274.34 (-1302.16%) 13.66 ( 30.20%) 19.57 length=525, char=0: 274.64 (-1297.78%) 13.56 ( 30.99%) 19.65 length=526, char=0: 275.20 (-1300.04%) 13.56 ( 31.01%) 19.66 length=527, char=0: 275.66 (-1302.86%) 13.56 ( 30.99%) 19.65 length=1024, char=0: 524.46 (-2169.75%) 20.12 ( 12.92%) 23.11 length=1025, char=0: 525.14 (-2124.63%) 21.62 ( 8.40%) 23.61 length=1026, char=0: 525.59 (-2125.36%) 21.88 ( 7.37%) 23.62 length=1027, char=0: 525.98 (-2127.14%) 21.62 ( 8.46%) 23.62 length=1028, char=0: 526.68 (-2131.10%) 21.62 ( 8.42%) 23.61 length=1029, char=0: 527.10 (-2131.70%) 21.79 ( 7.73%) 23.62 length=1030, char=0: 527.54 (-2118.51%) 21.62 ( 9.10%) 23.78 length=1031, char=0: 527.98 (-2136.37%) 21.62 ( 8.43%) 23.61 length=1032, char=0: 528.70 (-2139.38%) 21.62 ( 8.43%) 23.61 length=1033, char=0: 529.25 (-2124.37%) 21.62 ( 9.11%) 23.79 length=1034, char=0: 529.48 (-2142.95%) 21.62 ( 8.43%) 23.61 length=1035, char=0: 530.11 (-2145.13%) 21.62 ( 8.44%) 23.61 length=1036, char=0: 530.76 (-2147.10%) 21.79 ( 7.73%) 23.62 length=1037, char=0: 531.03 (-2149.45%) 21.62 ( 8.42%) 23.61 length=1038, char=0: 531.64 (-2151.87%) 21.62 ( 8.42%) 23.61 length=1039, char=0: 531.99 (-2151.63%) 21.80 ( 7.75%) 23.63 * sysdeps/aarch64/memset-reg.h: New file. * sysdeps/aarch64/memset.S: Use it. (__memset): Rename to MEMSET macro. [ZVA_MACRO]: Use zva_macro. * sysdeps/aarch64/multiarch/Makefile (sysdep_routines): Add memset_generic and memset_falkor. * sysdeps/aarch64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add memset ifuncs. * sysdeps/aarch64/multiarch/init-arch.h (INIT_ARCH): New local variable zva_size. * sysdeps/aarch64/multiarch/memset.c: New file. * sysdeps/aarch64/multiarch/memset_generic.S: New file. * sysdeps/aarch64/multiarch/memset_falkor.S: New file. * sysdeps/aarch64/multiarch/rtld-memset.S: New file. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (DCZID_DZP_MASK): New macro. (DCZID_BS_MASK): Likewise. (init_cpu_features): Read and set zva_size. * sysdeps/unix/sysv/linux/aarch64/cpu-features.h (struct cpu_features): New member zva_size.
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#define DCZID_DZP_MASK (1 << 4)
#define DCZID_BS_MASK (0xf)
#if HAVE_TUNABLES
struct cpu_list
{
const char *name;
uint64_t midr;
};
static struct cpu_list cpu_list[] = {
{"falkor", 0x510FC000},
{"thunderxt88", 0x430F0A10},
{"thunderx2t99", 0x431F0AF0},
{"thunderx2t99p1", 0x420F5160},
{"phecda", 0x680F0000},
{"ares", 0x411FD0C0},
{"emag", 0x503F0001},
{"kunpeng920", 0x481FD010},
{"generic", 0x0}
};
static uint64_t
get_midr_from_mcpu (const char *mcpu)
{
for (int i = 0; i < sizeof (cpu_list) / sizeof (struct cpu_list); i++)
if (strcmp (mcpu, cpu_list[i].name) == 0)
return cpu_list[i].midr;
return UINT64_MAX;
}
#endif
static inline void
init_cpu_features (struct cpu_features *cpu_features)
{
register uint64_t midr = UINT64_MAX;
#if HAVE_TUNABLES
/* Get the tunable override. */
const char *mcpu = TUNABLE_GET (glibc, cpu, name, const char *, NULL);
if (mcpu != NULL)
midr = get_midr_from_mcpu (mcpu);
#endif
/* If there was no useful tunable override, query the MIDR if the kernel
allows it. */
if (midr == UINT64_MAX)
{
if (GLRO (dl_hwcap) & HWCAP_CPUID)
asm volatile ("mrs %0, midr_el1" : "=r"(midr));
else
midr = 0;
}
cpu_features->midr_el1 = midr;
aarch64: Optimized memset for falkor The generic memset reads dczid_el0 on every memset. This has a significant impact on falkor for a range of sizes because reading dczid_el0 is slow. The DZP bit in the dczid_el0 register does not change dynamically, so it is safe to read once during program startup. With this patch dczid_el0 is read once during startup and zva_size is cached. This is used to invoke the falkor-specific memset; the generic memset routine remains unchanged. The gains due to this are significant for falkor, with run time reductions as high as 48%. Here's a sample from the falkor tests: Function: memset Variant: walk simple_memset __memset_falkor __memset_generic ===================================================================== length=256, char=0: 139.96 (-698.28%) 9.07 ( 48.26%) 17.53 length=257, char=0: 140.50 (-699.03%) 9.53 ( 45.80%) 17.58 length=258, char=0: 140.96 (-703.95%) 9.58 ( 45.36%) 17.53 length=259, char=0: 141.56 (-705.16%) 9.53 ( 45.79%) 17.58 length=260, char=0: 142.15 (-710.76%) 9.57 ( 45.39%) 17.53 length=261, char=0: 142.50 (-710.39%) 9.53 ( 45.78%) 17.58 length=262, char=0: 142.97 (-715.09%) 9.57 ( 45.42%) 17.54 length=263, char=0: 143.51 (-716.18%) 9.53 ( 45.80%) 17.58 length=264, char=0: 143.93 (-720.55%) 9.58 ( 45.39%) 17.54 length=265, char=0: 144.56 (-722.07%) 9.53 ( 45.80%) 17.59 length=266, char=0: 144.98 (-726.42%) 9.58 ( 45.42%) 17.54 length=267, char=0: 145.53 (-727.53%) 9.53 ( 45.80%) 17.59 length=268, char=0: 146.25 (-731.81%) 9.53 ( 45.79%) 17.58 length=269, char=0: 146.52 (-735.39%) 9.53 ( 45.66%) 17.54 length=270, char=0: 146.97 (-735.81%) 9.53 ( 45.80%) 17.58 length=271, char=0: 147.54 (-741.08%) 9.58 ( 45.38%) 17.54 length=512, char=0: 268.26 (-1307.85%) 12.06 ( 36.71%) 19.05 length=513, char=0: 268.73 (-1273.89%) 13.56 ( 30.68%) 19.56 length=514, char=0: 269.31 (-1276.89%) 13.56 ( 30.68%) 19.56 length=515, char=0: 269.73 (-1279.05%) 13.56 ( 30.68%) 19.56 length=516, char=0: 270.34 (-1282.24%) 13.56 ( 30.67%) 19.56 length=517, char=0: 270.83 (-1284.71%) 13.56 ( 30.66%) 19.56 length=518, char=0: 271.20 (-1286.54%) 13.56 ( 30.67%) 19.56 length=519, char=0: 271.67 (-1288.67%) 13.65 ( 30.24%) 19.56 length=520, char=0: 272.14 (-1291.04%) 13.65 ( 30.22%) 19.56 length=521, char=0: 272.66 (-1293.69%) 13.65 ( 30.23%) 19.56 length=522, char=0: 273.14 (-1296.13%) 13.65 ( 30.20%) 19.56 length=523, char=0: 273.64 (-1298.75%) 13.65 ( 30.23%) 19.56 length=524, char=0: 274.34 (-1302.16%) 13.66 ( 30.20%) 19.57 length=525, char=0: 274.64 (-1297.78%) 13.56 ( 30.99%) 19.65 length=526, char=0: 275.20 (-1300.04%) 13.56 ( 31.01%) 19.66 length=527, char=0: 275.66 (-1302.86%) 13.56 ( 30.99%) 19.65 length=1024, char=0: 524.46 (-2169.75%) 20.12 ( 12.92%) 23.11 length=1025, char=0: 525.14 (-2124.63%) 21.62 ( 8.40%) 23.61 length=1026, char=0: 525.59 (-2125.36%) 21.88 ( 7.37%) 23.62 length=1027, char=0: 525.98 (-2127.14%) 21.62 ( 8.46%) 23.62 length=1028, char=0: 526.68 (-2131.10%) 21.62 ( 8.42%) 23.61 length=1029, char=0: 527.10 (-2131.70%) 21.79 ( 7.73%) 23.62 length=1030, char=0: 527.54 (-2118.51%) 21.62 ( 9.10%) 23.78 length=1031, char=0: 527.98 (-2136.37%) 21.62 ( 8.43%) 23.61 length=1032, char=0: 528.70 (-2139.38%) 21.62 ( 8.43%) 23.61 length=1033, char=0: 529.25 (-2124.37%) 21.62 ( 9.11%) 23.79 length=1034, char=0: 529.48 (-2142.95%) 21.62 ( 8.43%) 23.61 length=1035, char=0: 530.11 (-2145.13%) 21.62 ( 8.44%) 23.61 length=1036, char=0: 530.76 (-2147.10%) 21.79 ( 7.73%) 23.62 length=1037, char=0: 531.03 (-2149.45%) 21.62 ( 8.42%) 23.61 length=1038, char=0: 531.64 (-2151.87%) 21.62 ( 8.42%) 23.61 length=1039, char=0: 531.99 (-2151.63%) 21.80 ( 7.75%) 23.63 * sysdeps/aarch64/memset-reg.h: New file. * sysdeps/aarch64/memset.S: Use it. (__memset): Rename to MEMSET macro. [ZVA_MACRO]: Use zva_macro. * sysdeps/aarch64/multiarch/Makefile (sysdep_routines): Add memset_generic and memset_falkor. * sysdeps/aarch64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Add memset ifuncs. * sysdeps/aarch64/multiarch/init-arch.h (INIT_ARCH): New local variable zva_size. * sysdeps/aarch64/multiarch/memset.c: New file. * sysdeps/aarch64/multiarch/memset_generic.S: New file. * sysdeps/aarch64/multiarch/memset_falkor.S: New file. * sysdeps/aarch64/multiarch/rtld-memset.S: New file. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (DCZID_DZP_MASK): New macro. (DCZID_BS_MASK): Likewise. (init_cpu_features): Read and set zva_size. * sysdeps/unix/sysv/linux/aarch64/cpu-features.h (struct cpu_features): New member zva_size.
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/* Check if ZVA is enabled. */
unsigned dczid;
asm volatile ("mrs %0, dczid_el0" : "=r"(dczid));
if ((dczid & DCZID_DZP_MASK) == 0)
cpu_features->zva_size = 4 << (dczid & DCZID_BS_MASK);
}