From 21841f0d562f0e944c4d267a28cc3ebd19c847e9 Mon Sep 17 00:00:00 2001 From: Mahesh Bodapati Date: Tue, 1 Aug 2023 07:41:17 -0500 Subject: PowerPC: Influence cpu/arch hwcap features via GLIBC_TUNABLES This patch enables the option to influence hwcaps used by PowerPC. The environment variable, GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,-zzz...., can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature xxx and zzz, where the feature name is case-sensitive and has to match the ones mentioned in the file{sysdeps/powerpc/dl-procinfo.c}. Note that the hwcap tunables only used in the IFUNC selection. Reviewed-by: Adhemerval Zanella --- sysdeps/unix/sysv/linux/powerpc/Makefile | 11 +- sysdeps/unix/sysv/linux/powerpc/cpu-features.c | 124 ++++++++++++++++++++ sysdeps/unix/sysv/linux/powerpc/cpu-features.h | 130 +++++++++++++++++++++ .../unix/sysv/linux/powerpc/tst-hwcap-tunables.c | 128 ++++++++++++++++++++ 4 files changed, 390 insertions(+), 3 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/powerpc/cpu-features.c create mode 100644 sysdeps/unix/sysv/linux/powerpc/cpu-features.h create mode 100644 sysdeps/unix/sysv/linux/powerpc/tst-hwcap-tunables.c (limited to 'sysdeps/unix/sysv') diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile index 93783cae00..24827efe79 100644 --- a/sysdeps/unix/sysv/linux/powerpc/Makefile +++ b/sysdeps/unix/sysv/linux/powerpc/Makefile @@ -23,9 +23,14 @@ ifeq ($(subdir),misc) sysdep_headers += bits/ppc.h sysdep_routines += get_timebase_freq tests-static += test-gettimebasefreq-static -tests += $(tests-static) -tests += test-gettimebasefreq -tests += test-powerpc-linux-sysconf +tests += \ + $(tests-static) \ + test-gettimebasefreq \ + test-powerpc-linux-sysconf \ + tst-hwcap-tunables \ + # tests + +tst-hwcap-tunables-ARGS = -- $(host-test-program-cmd) endif ifeq ($(subdir),csu) diff --git a/sysdeps/unix/sysv/linux/powerpc/cpu-features.c b/sysdeps/unix/sysv/linux/powerpc/cpu-features.c new file mode 100644 index 0000000000..7c6e20e702 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/cpu-features.c @@ -0,0 +1,124 @@ +/* Initialize cpu feature data. PowerPC version. + Copyright (C) 2017-2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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 + . */ + +#include +#include +#include +#include +#include +#include + +static void +TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp) +{ + /* The current IFUNC selection is always using the most recent + features which are available via AT_HWCAP or AT_HWCAP2. But in + some scenarios it is useful to adjust this selection. + + The environment variable: + + GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,.... + + Can be used to enable HWCAP/HWCAP2 feature yyy, disable HWCAP/HWCAP2 + feature xxx, where the feature name is case-sensitive and has to match + the ones mentioned in the file{sysdeps/powerpc/dl-procinfo.c}. */ + + /* Copy the features from dl_powerpc_cpu_features, which contains the + features provided by AT_HWCAP and AT_HWCAP2. */ + struct cpu_features *cpu_features = &GLRO(dl_powerpc_cpu_features); + unsigned long int tcbv_hwcap = cpu_features->hwcap; + unsigned long int tcbv_hwcap2 = cpu_features->hwcap2; + const char *token = valp->strval; + do + { + const char *token_end, *feature; + bool disable; + size_t token_len, i, feature_len, offset = 0; + /* Find token separator or end of string. */ + for (token_end = token; *token_end != ','; token_end++) + if (*token_end == '\0') + break; + + /* Determine feature. */ + token_len = token_end - token; + if (*token == '-') + { + disable = true; + feature = token + 1; + feature_len = token_len - 1; + } + else + { + disable = false; + feature = token; + feature_len = token_len; + } + for (i = 0; i < array_length (hwcap_tunables); ++i) + { + const char *hwcap_name = hwcap_names + offset; + size_t hwcap_name_len = strlen (hwcap_name); + /* Check the tunable name on the supported list. */ + if (hwcap_name_len == feature_len + && memcmp (feature, hwcap_name, feature_len) == 0) + { + /* Update the hwcap and hwcap2 bits. */ + if (disable) + { + /* Id is 1 for hwcap2 tunable. */ + if (hwcap_tunables[i].id) + cpu_features->hwcap2 &= ~(hwcap_tunables[i].mask); + else + cpu_features->hwcap &= ~(hwcap_tunables[i].mask); + } + else + { + /* Enable the features and also check that no unsupported + features were enabled by user. */ + if (hwcap_tunables[i].id) + cpu_features->hwcap2 |= (tcbv_hwcap2 & hwcap_tunables[i].mask); + else + cpu_features->hwcap |= (tcbv_hwcap & hwcap_tunables[i].mask); + } + break; + } + offset += hwcap_name_len + 1; + } + token += token_len; + /* ... and skip token separator for next round. */ + if (*token == ',') + token++; + } + while (*token != '\0'); +} + +static inline void +init_cpu_features (struct cpu_features *cpu_features, uint64_t hwcaps[]) +{ + /* Fill the cpu_features with the supported hwcaps + which are set by __tcb_parse_hwcap_and_convert_at_platform. */ + cpu_features->hwcap = hwcaps[0]; + cpu_features->hwcap2 = hwcaps[1]; + /* Default is to use aligned memory access on optimized function unless + tunables is enable, since for this case user can explicit disable + unaligned optimizations. */ + int32_t cached_memfunc = TUNABLE_GET (glibc, cpu, cached_memopt, int32_t, + NULL); + cpu_features->use_cached_memopt = (cached_memfunc > 0); + TUNABLE_GET (glibc, cpu, hwcaps, tunable_val_t *, + TUNABLE_CALLBACK (set_hwcaps)); +} diff --git a/sysdeps/unix/sysv/linux/powerpc/cpu-features.h b/sysdeps/unix/sysv/linux/powerpc/cpu-features.h new file mode 100644 index 0000000000..e5fce88e5e --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/cpu-features.h @@ -0,0 +1,130 @@ +/* Initialize cpu feature data. PowerPC version. + Copyright (C) 2017-2023 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 + . */ + +#ifndef __CPU_FEATURES_POWERPC_H +# define __CPU_FEATURES_POWERPC_H + +#include +#include + +struct cpu_features +{ + bool use_cached_memopt; + unsigned long int hwcap; + unsigned long int hwcap2; +}; + +static const char hwcap_names[] = { + "4xxmac\0" + "altivec\0" + "arch_2_05\0" + "arch_2_06\0" + "archpmu\0" + "booke\0" + "cellbe\0" + "dfp\0" + "efpdouble\0" + "efpsingle\0" + "fpu\0" + "ic_snoop\0" + "mmu\0" + "notb\0" + "pa6t\0" + "power4\0" + "power5\0" + "power5+\0" + "power6x\0" + "ppc32\0" + "ppc601\0" + "ppc64\0" + "ppcle\0" + "smt\0" + "spe\0" + "true_le\0" + "ucache\0" + "vsx\0" + "arch_2_07\0" + "dscr\0" + "ebb\0" + "htm\0" + "htm-nosc\0" + "htm-no-suspend\0" + "isel\0" + "tar\0" + "vcrypto\0" + "arch_3_00\0" + "ieee128\0" + "darn\0" + "scv\0" + "arch_3_1\0" + "mma\0" +}; + +static const struct +{ + unsigned int mask; + bool id; +} hwcap_tunables[] = { + /* AT_HWCAP tunable masks. */ + { PPC_FEATURE_HAS_4xxMAC, 0 }, + { PPC_FEATURE_HAS_ALTIVEC, 0 }, + { PPC_FEATURE_ARCH_2_05, 0 }, + { PPC_FEATURE_ARCH_2_06, 0 }, + { PPC_FEATURE_PSERIES_PERFMON_COMPAT, 0 }, + { PPC_FEATURE_BOOKE, 0 }, + { PPC_FEATURE_CELL_BE, 0 }, + { PPC_FEATURE_HAS_DFP, 0 }, + { PPC_FEATURE_HAS_EFP_DOUBLE, 0 }, + { PPC_FEATURE_HAS_EFP_SINGLE, 0 }, + { PPC_FEATURE_HAS_FPU, 0 }, + { PPC_FEATURE_ICACHE_SNOOP, 0 }, + { PPC_FEATURE_HAS_MMU, 0 }, + { PPC_FEATURE_NO_TB, 0 }, + { PPC_FEATURE_PA6T, 0 }, + { PPC_FEATURE_POWER4, 0 }, + { PPC_FEATURE_POWER5, 0 }, + { PPC_FEATURE_POWER5_PLUS, 0 }, + { PPC_FEATURE_POWER6_EXT, 0 }, + { PPC_FEATURE_32, 0 }, + { PPC_FEATURE_601_INSTR, 0 }, + { PPC_FEATURE_64, 0 }, + { PPC_FEATURE_PPC_LE, 0 }, + { PPC_FEATURE_SMT, 0 }, + { PPC_FEATURE_HAS_SPE, 0 }, + { PPC_FEATURE_TRUE_LE, 0 }, + { PPC_FEATURE_UNIFIED_CACHE, 0 }, + { PPC_FEATURE_HAS_VSX, 0 }, + + /* AT_HWCAP2 tunable masks. */ + { PPC_FEATURE2_ARCH_2_07, 1 }, + { PPC_FEATURE2_HAS_DSCR, 1 }, + { PPC_FEATURE2_HAS_EBB, 1 }, + { PPC_FEATURE2_HAS_HTM, 1 }, + { PPC_FEATURE2_HTM_NOSC, 1 }, + { PPC_FEATURE2_HTM_NO_SUSPEND, 1 }, + { PPC_FEATURE2_HAS_ISEL, 1 }, + { PPC_FEATURE2_HAS_TAR, 1 }, + { PPC_FEATURE2_HAS_VEC_CRYPTO, 1 }, + { PPC_FEATURE2_ARCH_3_00, 1 }, + { PPC_FEATURE2_HAS_IEEE128, 1 }, + { PPC_FEATURE2_DARN, 1 }, + { PPC_FEATURE2_SCV, 1 }, + { PPC_FEATURE2_ARCH_3_1, 1 }, + { PPC_FEATURE2_MMA, 1 }, +}; + +#endif /* __CPU_FEATURES_H */ diff --git a/sysdeps/unix/sysv/linux/powerpc/tst-hwcap-tunables.c b/sysdeps/unix/sysv/linux/powerpc/tst-hwcap-tunables.c new file mode 100644 index 0000000000..2631016a3a --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/tst-hwcap-tunables.c @@ -0,0 +1,128 @@ +/* Tests for powerpc GLIBC_TUNABLES=glibc.cpu.hwcaps filter. + Copyright (C) 2023 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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 + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Nonzero if the program gets called via `exec'. */ +#define CMDLINE_OPTIONS \ + { "restart", no_argument, &restart, 1 }, +static int restart; + +/* Hold the four initial argument used to respawn the process, plus the extra + '--direct', '--restart', and the function to check */ +static char *spargs[8]; +static int fc; + +/* Called on process re-execution. */ +_Noreturn static void +handle_restart (int argc, char *argv[]) +{ + TEST_VERIFY_EXIT (argc == 1); + const char *funcname = argv[0]; + + struct libc_ifunc_impl impls[32]; + int cnt = __libc_ifunc_impl_list ("memcpy", impls, array_length (impls)); + if (cnt == 0) + _exit (EXIT_SUCCESS); + TEST_VERIFY_EXIT (cnt >= 1); + for (int i = 0; i < cnt; i++) { + if (strcmp (impls[i].name, funcname) == 0) + { + TEST_COMPARE (impls[i].usable, false); + break; + } + } + + _exit (EXIT_SUCCESS); +} + +static void +run_test (const char *filter, const char *funcname) +{ + printf ("info: checking filter %s (expect %s ifunc selection to be removed)\n", + filter, funcname); + char *tunable = xasprintf ("GLIBC_TUNABLES=glibc.cpu.hwcaps=%s", filter); + char *const newenvs[] = { (char*) tunable, NULL }; + spargs[fc] = (char *) funcname; + + pid_t pid; + TEST_COMPARE (posix_spawn (&pid, spargs[0], NULL, NULL, spargs, newenvs), 0); + int status; + TEST_COMPARE (xwaitpid (pid, &status, 0), pid); + TEST_VERIFY (WIFEXITED (status)); + TEST_VERIFY (!WIFSIGNALED (status)); + TEST_COMPARE (WEXITSTATUS (status), 0); + + free (tunable); +} + +static int +do_test (int argc, char *argv[]) +{ + if (restart) + handle_restart (argc - 1, &argv[1]); + + TEST_VERIFY_EXIT (argc == 2 || argc == 5); + + int i; + for (i = 0; i < argc - 1; i++) + spargs[i] = argv[i + 1]; + spargs[i++] = (char *) "--direct"; + spargs[i++] = (char *) "--restart"; + fc = i++; + spargs[i] = NULL; + + unsigned long int hwcap = getauxval (AT_HWCAP); + unsigned long int hwcap2 = getauxval (AT_HWCAP2); + if (__WORDSIZE == 64) + { + if (hwcap2 & PPC_FEATURE2_ARCH_3_1) + run_test ("-arch_3_1", "__memcpy_power10"); + if (hwcap2 & PPC_FEATURE2_ARCH_2_07) + run_test ("-arch_2_07", "__memcpy_power8_cached"); + if (hwcap & PPC_FEATURE_ARCH_2_06) + run_test ("-arch_2_06", "__memcpy_power7"); + if (hwcap & PPC_FEATURE_ARCH_2_05) + run_test ("-arch_2_06,-arch_2_05","__memcpy_power6"); + run_test ("-arch_2_06,-arch_2_05,-power5+,-power5,-power4", "__memcpy_power4"); + } + else + { + if (hwcap & PPC_FEATURE_HAS_VSX) + run_test ("-vsx", "__memcpy_power7"); + if (hwcap & PPC_FEATURE_ARCH_2_06) + run_test ("-arch_2_06", "__memcpy_a2"); + if (hwcap & PPC_FEATURE_ARCH_2_05) + run_test ("-arch_2_05", "__memcpy_power6"); + } + return 0; +} + +#define TEST_FUNCTION_ARGV do_test +#include -- cgit 1.4.1