| Message ID | 20230630151500.506180-1-bmahi496@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] PowerPC: Influence cpu/arch hwcap features via GLIBC_TUNABLES. | expand |
On 6/30/23 10:15 AM, bmahi496@linux.ibm.com wrote: > From: Mahesh Bodapati <mahesh.bodapati@ibm.com> > > 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 tunable only handles the features which are really used > in the IFUNC selection. All others are ignored as the values are only > used inside glibc. > --- > manual/tunables.texi | 5 +- > sysdeps/powerpc/cpu-features.c | 93 ++++++++++++++++++- > sysdeps/powerpc/cpu-features.h | 57 ++++++++++++ > sysdeps/powerpc/dl-tunables.list | 3 + > sysdeps/powerpc/hwcapinfo.c | 4 + > .../powerpc32/power4/multiarch/init-arch.h | 10 +- > sysdeps/powerpc/powerpc64/dl-machine.h | 2 - > .../powerpc64/multiarch/ifunc-impl-list.c | 7 +- > 8 files changed, 170 insertions(+), 11 deletions(-) > > diff --git a/manual/tunables.texi b/manual/tunables.texi > index 4ca0e42a11..776fd93fd9 100644 > --- a/manual/tunables.texi > +++ b/manual/tunables.texi > @@ -513,7 +513,10 @@ On s390x, the supported HWCAP and STFLE features can be found in > @code{sysdeps/s390/cpu-features.c}. In addition the user can also set > a CPU arch-level like @code{z13} instead of single HWCAP and STFLE features. > > -This tunable is specific to i386, x86-64 and s390x. > +On powerpc, the supported HWCAP and HWCAP2 features can be found in > +@code{sysdeps/powerpc/dl-procinfo.c}. > + > +This tunable is specific to i386, x86-64, s390x and powerpc. > @end deftp > > @deftp Tunable glibc.cpu.cached_memopt > diff --git a/sysdeps/powerpc/cpu-features.c b/sysdeps/powerpc/cpu-features.c > index 0ef3cf89d2..1239a01928 100644 > --- a/sysdeps/powerpc/cpu-features.c > +++ b/sysdeps/powerpc/cpu-features.c > @@ -19,14 +19,105 @@ > #include <stdint.h> > #include <cpu-features.h> > #include <elf/dl-tunables.h> > +#include <unistd.h> > +#include <string.h> > +#define MEMCMP_DEFAULT memcmp > +#define STRLEN_DEFAULT strlen > + > +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 Looks like more than 80 characters length. > + provided by AT_HWCAP and AT_HWCAP2. */ > + struct cpu_features *cpu_features = &GLRO(dl_powerpc_cpu_features); > + const char *token = valp->strval; > + do > + { > + const char *token_end, *feature; > + bool disable; > + size_t token_len, i, feature_len; > + /* 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; hwcap_tunables[i].name != NULL; ++i) Minor comment. Space after =. > + { > + /* Check the tunable name on the supported list. */ > + if (STRLEN_DEFAULT (hwcap_tunables[i].name) == feature_len > + && MEMCMP_DEFAULT (feature, hwcap_tunables[i].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 > + { > + if (hwcap_tunables[i].id) > + cpu_features->hwcap2 |= (hwcap_tunables[i].mask); > + else > + cpu_features->hwcap |= (hwcap_tunables[i].mask); > + } > + } > + } > + 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) > +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)); > + > + /* Copy back the features after checking that no unsupported features > + were enabled by user. */ > + cpu_features->hwcap &= hwcaps[0]; > + cpu_features->hwcap2 &= hwcaps[1]; > } > diff --git a/sysdeps/powerpc/cpu-features.h b/sysdeps/powerpc/cpu-features.h > index d316dc3d64..6839c3085b 100644 > --- a/sysdeps/powerpc/cpu-features.h > +++ b/sysdeps/powerpc/cpu-features.h > @@ -19,10 +19,67 @@ > # define __CPU_FEATURES_POWERPC_H > > #include <stdbool.h> > +#include <sys/auxv.h> > > struct cpu_features > { > bool use_cached_memopt; > + unsigned long int hwcap; > + unsigned long int hwcap2; > +}; > + > +static const struct > +{ > + const char *name; > + int mask; > + bool id; > +} hwcap_tunables[] = { > + /* AT_HWCAP tunable masks. */ > + { "4xxmac", PPC_FEATURE_HAS_4xxMAC, 0 }, > + { "altivec", PPC_FEATURE_HAS_ALTIVEC, 0 }, > + { "arch_2_05", PPC_FEATURE_ARCH_2_05, 0 }, > + { "arch_2_06", PPC_FEATURE_ARCH_2_06, 0 }, > + { "archpmu", PPC_FEATURE_PSERIES_PERFMON_COMPAT, 0 }, > + { "booke", PPC_FEATURE_BOOKE, 0 }, > + { "cellbe", PPC_FEATURE_CELL_BE, 0 }, > + { "dfp", PPC_FEATURE_HAS_DFP, 0 }, > + { "efpdouble", PPC_FEATURE_HAS_EFP_DOUBLE, 0 }, > + { "efpsingle", PPC_FEATURE_HAS_EFP_SINGLE, 0 }, > + { "fpu", PPC_FEATURE_HAS_FPU, 0 }, > + { "ic_snoop", PPC_FEATURE_ICACHE_SNOOP, 0 }, > + { "mmu", PPC_FEATURE_HAS_MMU, 0 }, > + { "notb", PPC_FEATURE_NO_TB, 0 }, > + { "pa6t", PPC_FEATURE_PA6T, 0 }, > + { "power4", PPC_FEATURE_POWER4, 0 }, > + { "power5", PPC_FEATURE_POWER5, 0 }, > + { "power5+", PPC_FEATURE_POWER5_PLUS, 0 }, > + { "power6x", PPC_FEATURE_POWER6_EXT, 0 }, > + { "ppc32", PPC_FEATURE_32, 0 }, > + { "ppc601", PPC_FEATURE_601_INSTR, 0 }, > + { "ppc64", PPC_FEATURE_64, 0 }, > + { "ppcle", PPC_FEATURE_PPC_LE, 0 }, > + { "smt", PPC_FEATURE_SMT, 0 }, > + { "spe", PPC_FEATURE_HAS_SPE, 0 }, > + { "true_le", PPC_FEATURE_TRUE_LE, 0 }, > + { "ucache", PPC_FEATURE_UNIFIED_CACHE, 0 }, > + { "vsx", PPC_FEATURE_HAS_VSX, 0 }, > + > + /* AT_HWCAP2 tunable masks. */ > + { "arch_2_07", PPC_FEATURE2_ARCH_2_07, 1 }, > + { "dscr", PPC_FEATURE2_HAS_DSCR, 1 }, > + { "ebb", PPC_FEATURE2_HAS_EBB, 1 }, > + { "htm", PPC_FEATURE2_HAS_HTM, 1 }, > + { "htm-nosc", PPC_FEATURE2_HTM_NOSC, 1 }, > + { "htm-no-suspend", PPC_FEATURE2_HTM_NO_SUSPEND, 1 }, > + { "isel", PPC_FEATURE2_HAS_ISEL, 1 }, > + { "tar", PPC_FEATURE2_HAS_TAR, 1 }, > + { "vcrypto", PPC_FEATURE2_HAS_VEC_CRYPTO, 1 }, > + { "arch_3_00", PPC_FEATURE2_ARCH_3_00, 1 }, > + { "ieee128", PPC_FEATURE2_HAS_IEEE128, 1 }, > + { "darn", PPC_FEATURE2_DARN, 1 }, > + { "scv", PPC_FEATURE2_SCV, 1 }, > + { "arch_3_1", PPC_FEATURE2_ARCH_3_1, 1 }, > + { "mma", PPC_FEATURE2_MMA, 1 }, > }; > > #endif /* __CPU_FEATURES_H */ > diff --git a/sysdeps/powerpc/dl-tunables.list b/sysdeps/powerpc/dl-tunables.list > index 87d6235c75..807b7f8013 100644 > --- a/sysdeps/powerpc/dl-tunables.list > +++ b/sysdeps/powerpc/dl-tunables.list > @@ -24,5 +24,8 @@ glibc { > maxval: 1 > default: 0 > } > + hwcaps { > + type: STRING > + } > } > } > diff --git a/sysdeps/powerpc/hwcapinfo.c b/sysdeps/powerpc/hwcapinfo.c > index e26e64d99e..f2c473c556 100644 > --- a/sysdeps/powerpc/hwcapinfo.c > +++ b/sysdeps/powerpc/hwcapinfo.c > @@ -19,6 +19,7 @@ > #include <unistd.h> > #include <shlib-compat.h> > #include <dl-procinfo.h> > +#include <cpu-features.c> > > tcbhead_t __tcb __attribute__ ((visibility ("hidden"))); > > @@ -63,6 +64,9 @@ __tcb_parse_hwcap_and_convert_at_platform (void) > else if (h1 & PPC_FEATURE_POWER5) > h1 |= PPC_FEATURE_POWER4; > > + uint64_t array_hwcaps[] = { h1, h2 }; > + init_cpu_features (&GLRO(dl_powerpc_cpu_features), array_hwcaps); > + > /* Consolidate both HWCAP and HWCAP2 into a single doubleword so that > we can read both in a single load later. */ > __tcb.hwcap = (h1 << 32) | (h2 & 0xffffffff); > diff --git a/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h b/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h > index 3dd00e02ee..a0bbd12012 100644 > --- a/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h > +++ b/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h > @@ -16,6 +16,7 @@ > <https://www.gnu.org/licenses/>. */ > > #include <ldsodefs.h> > +#include <cpu-features.h> > > /* The code checks if _rtld_global_ro was realocated before trying to access > the dl_hwcap field. The assembly is to make the compiler not optimize the > @@ -32,11 +33,12 @@ > # define __GLRO(value) GLRO(value) > #endif > > -/* dl_hwcap contains only the latest supported ISA, the macro checks which is > - and fills the previous ones. */ > +/* Get the hardware information post the tunables set , the macro checks > + it and fills the previous ones. */ > #define INIT_ARCH() \ > - unsigned long int hwcap = __GLRO(dl_hwcap); \ > - unsigned long int __attribute__((unused)) hwcap2 = __GLRO(dl_hwcap2); \ > + const struct cpu_features *features = &GLRO(dl_powerpc_cpu_features); \ > + unsigned long int hwcap = features->hwcap; \ > + unsigned long int __attribute__((unused)) hwcap2 = features->hwcap2; \ > bool __attribute__((unused)) use_cached_memopt = \ > __GLRO(dl_powerpc_cpu_features.use_cached_memopt); \ > if (hwcap & PPC_FEATURE_ARCH_2_06) \ > diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h > index 9b8943bc91..449208e86f 100644 > --- a/sysdeps/powerpc/powerpc64/dl-machine.h > +++ b/sysdeps/powerpc/powerpc64/dl-machine.h > @@ -27,7 +27,6 @@ > #include <dl-tls.h> > #include <sysdep.h> > #include <hwcapinfo.h> > -#include <cpu-features.c> > #include <dl-static-tls.h> > #include <dl-funcdesc.h> > #include <dl-machine-rel.h> > @@ -297,7 +296,6 @@ static inline void __attribute__ ((unused)) > dl_platform_init (void) > { > __tcb_parse_hwcap_and_convert_at_platform (); > - init_cpu_features (&GLRO(dl_powerpc_cpu_features)); > } > #endif > > diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c > index ebe9434052..fc26dd0e17 100644 > --- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c > +++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c Do we need to change powerpc32 ifunc-impl-list.c as well? > @@ -17,6 +17,7 @@ > <https://www.gnu.org/licenses/>. */ > > #include <assert.h> > +#include <cpu-features.h> > #include <string.h> > #include <wchar.h> > #include <ldsodefs.h> > @@ -27,9 +28,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, > size_t max) > { > size_t i = max; > - > - unsigned long int hwcap = GLRO(dl_hwcap); > - unsigned long int hwcap2 = GLRO(dl_hwcap2); > + const struct cpu_features *features = &GLRO(dl_powerpc_cpu_features); > + unsigned long int hwcap = features->hwcap; > + unsigned long int hwcap2 = features->hwcap2; > #ifdef SHARED > int cacheline_size = GLRO(dl_cache_line_size); > #endif LGTM.
diff --git a/manual/tunables.texi b/manual/tunables.texi index 4ca0e42a11..776fd93fd9 100644 --- a/manual/tunables.texi +++ b/manual/tunables.texi @@ -513,7 +513,10 @@ On s390x, the supported HWCAP and STFLE features can be found in @code{sysdeps/s390/cpu-features.c}. In addition the user can also set a CPU arch-level like @code{z13} instead of single HWCAP and STFLE features. -This tunable is specific to i386, x86-64 and s390x. +On powerpc, the supported HWCAP and HWCAP2 features can be found in +@code{sysdeps/powerpc/dl-procinfo.c}. + +This tunable is specific to i386, x86-64, s390x and powerpc. @end deftp @deftp Tunable glibc.cpu.cached_memopt diff --git a/sysdeps/powerpc/cpu-features.c b/sysdeps/powerpc/cpu-features.c index 0ef3cf89d2..1239a01928 100644 --- a/sysdeps/powerpc/cpu-features.c +++ b/sysdeps/powerpc/cpu-features.c @@ -19,14 +19,105 @@ #include <stdint.h> #include <cpu-features.h> #include <elf/dl-tunables.h> +#include <unistd.h> +#include <string.h> +#define MEMCMP_DEFAULT memcmp +#define STRLEN_DEFAULT strlen + +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); + const char *token = valp->strval; + do + { + const char *token_end, *feature; + bool disable; + size_t token_len, i, feature_len; + /* 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; hwcap_tunables[i].name != NULL; ++i) + { + /* Check the tunable name on the supported list. */ + if (STRLEN_DEFAULT (hwcap_tunables[i].name) == feature_len + && MEMCMP_DEFAULT (feature, hwcap_tunables[i].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 + { + if (hwcap_tunables[i].id) + cpu_features->hwcap2 |= (hwcap_tunables[i].mask); + else + cpu_features->hwcap |= (hwcap_tunables[i].mask); + } + } + } + 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) +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)); + + /* Copy back the features after checking that no unsupported features + were enabled by user. */ + cpu_features->hwcap &= hwcaps[0]; + cpu_features->hwcap2 &= hwcaps[1]; } diff --git a/sysdeps/powerpc/cpu-features.h b/sysdeps/powerpc/cpu-features.h index d316dc3d64..6839c3085b 100644 --- a/sysdeps/powerpc/cpu-features.h +++ b/sysdeps/powerpc/cpu-features.h @@ -19,10 +19,67 @@ # define __CPU_FEATURES_POWERPC_H #include <stdbool.h> +#include <sys/auxv.h> struct cpu_features { bool use_cached_memopt; + unsigned long int hwcap; + unsigned long int hwcap2; +}; + +static const struct +{ + const char *name; + int mask; + bool id; +} hwcap_tunables[] = { + /* AT_HWCAP tunable masks. */ + { "4xxmac", PPC_FEATURE_HAS_4xxMAC, 0 }, + { "altivec", PPC_FEATURE_HAS_ALTIVEC, 0 }, + { "arch_2_05", PPC_FEATURE_ARCH_2_05, 0 }, + { "arch_2_06", PPC_FEATURE_ARCH_2_06, 0 }, + { "archpmu", PPC_FEATURE_PSERIES_PERFMON_COMPAT, 0 }, + { "booke", PPC_FEATURE_BOOKE, 0 }, + { "cellbe", PPC_FEATURE_CELL_BE, 0 }, + { "dfp", PPC_FEATURE_HAS_DFP, 0 }, + { "efpdouble", PPC_FEATURE_HAS_EFP_DOUBLE, 0 }, + { "efpsingle", PPC_FEATURE_HAS_EFP_SINGLE, 0 }, + { "fpu", PPC_FEATURE_HAS_FPU, 0 }, + { "ic_snoop", PPC_FEATURE_ICACHE_SNOOP, 0 }, + { "mmu", PPC_FEATURE_HAS_MMU, 0 }, + { "notb", PPC_FEATURE_NO_TB, 0 }, + { "pa6t", PPC_FEATURE_PA6T, 0 }, + { "power4", PPC_FEATURE_POWER4, 0 }, + { "power5", PPC_FEATURE_POWER5, 0 }, + { "power5+", PPC_FEATURE_POWER5_PLUS, 0 }, + { "power6x", PPC_FEATURE_POWER6_EXT, 0 }, + { "ppc32", PPC_FEATURE_32, 0 }, + { "ppc601", PPC_FEATURE_601_INSTR, 0 }, + { "ppc64", PPC_FEATURE_64, 0 }, + { "ppcle", PPC_FEATURE_PPC_LE, 0 }, + { "smt", PPC_FEATURE_SMT, 0 }, + { "spe", PPC_FEATURE_HAS_SPE, 0 }, + { "true_le", PPC_FEATURE_TRUE_LE, 0 }, + { "ucache", PPC_FEATURE_UNIFIED_CACHE, 0 }, + { "vsx", PPC_FEATURE_HAS_VSX, 0 }, + + /* AT_HWCAP2 tunable masks. */ + { "arch_2_07", PPC_FEATURE2_ARCH_2_07, 1 }, + { "dscr", PPC_FEATURE2_HAS_DSCR, 1 }, + { "ebb", PPC_FEATURE2_HAS_EBB, 1 }, + { "htm", PPC_FEATURE2_HAS_HTM, 1 }, + { "htm-nosc", PPC_FEATURE2_HTM_NOSC, 1 }, + { "htm-no-suspend", PPC_FEATURE2_HTM_NO_SUSPEND, 1 }, + { "isel", PPC_FEATURE2_HAS_ISEL, 1 }, + { "tar", PPC_FEATURE2_HAS_TAR, 1 }, + { "vcrypto", PPC_FEATURE2_HAS_VEC_CRYPTO, 1 }, + { "arch_3_00", PPC_FEATURE2_ARCH_3_00, 1 }, + { "ieee128", PPC_FEATURE2_HAS_IEEE128, 1 }, + { "darn", PPC_FEATURE2_DARN, 1 }, + { "scv", PPC_FEATURE2_SCV, 1 }, + { "arch_3_1", PPC_FEATURE2_ARCH_3_1, 1 }, + { "mma", PPC_FEATURE2_MMA, 1 }, }; #endif /* __CPU_FEATURES_H */ diff --git a/sysdeps/powerpc/dl-tunables.list b/sysdeps/powerpc/dl-tunables.list index 87d6235c75..807b7f8013 100644 --- a/sysdeps/powerpc/dl-tunables.list +++ b/sysdeps/powerpc/dl-tunables.list @@ -24,5 +24,8 @@ glibc { maxval: 1 default: 0 } + hwcaps { + type: STRING + } } } diff --git a/sysdeps/powerpc/hwcapinfo.c b/sysdeps/powerpc/hwcapinfo.c index e26e64d99e..f2c473c556 100644 --- a/sysdeps/powerpc/hwcapinfo.c +++ b/sysdeps/powerpc/hwcapinfo.c @@ -19,6 +19,7 @@ #include <unistd.h> #include <shlib-compat.h> #include <dl-procinfo.h> +#include <cpu-features.c> tcbhead_t __tcb __attribute__ ((visibility ("hidden"))); @@ -63,6 +64,9 @@ __tcb_parse_hwcap_and_convert_at_platform (void) else if (h1 & PPC_FEATURE_POWER5) h1 |= PPC_FEATURE_POWER4; + uint64_t array_hwcaps[] = { h1, h2 }; + init_cpu_features (&GLRO(dl_powerpc_cpu_features), array_hwcaps); + /* Consolidate both HWCAP and HWCAP2 into a single doubleword so that we can read both in a single load later. */ __tcb.hwcap = (h1 << 32) | (h2 & 0xffffffff); diff --git a/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h b/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h index 3dd00e02ee..a0bbd12012 100644 --- a/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h +++ b/sysdeps/powerpc/powerpc32/power4/multiarch/init-arch.h @@ -16,6 +16,7 @@ <https://www.gnu.org/licenses/>. */ #include <ldsodefs.h> +#include <cpu-features.h> /* The code checks if _rtld_global_ro was realocated before trying to access the dl_hwcap field. The assembly is to make the compiler not optimize the @@ -32,11 +33,12 @@ # define __GLRO(value) GLRO(value) #endif -/* dl_hwcap contains only the latest supported ISA, the macro checks which is - and fills the previous ones. */ +/* Get the hardware information post the tunables set , the macro checks + it and fills the previous ones. */ #define INIT_ARCH() \ - unsigned long int hwcap = __GLRO(dl_hwcap); \ - unsigned long int __attribute__((unused)) hwcap2 = __GLRO(dl_hwcap2); \ + const struct cpu_features *features = &GLRO(dl_powerpc_cpu_features); \ + unsigned long int hwcap = features->hwcap; \ + unsigned long int __attribute__((unused)) hwcap2 = features->hwcap2; \ bool __attribute__((unused)) use_cached_memopt = \ __GLRO(dl_powerpc_cpu_features.use_cached_memopt); \ if (hwcap & PPC_FEATURE_ARCH_2_06) \ diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h index 9b8943bc91..449208e86f 100644 --- a/sysdeps/powerpc/powerpc64/dl-machine.h +++ b/sysdeps/powerpc/powerpc64/dl-machine.h @@ -27,7 +27,6 @@ #include <dl-tls.h> #include <sysdep.h> #include <hwcapinfo.h> -#include <cpu-features.c> #include <dl-static-tls.h> #include <dl-funcdesc.h> #include <dl-machine-rel.h> @@ -297,7 +296,6 @@ static inline void __attribute__ ((unused)) dl_platform_init (void) { __tcb_parse_hwcap_and_convert_at_platform (); - init_cpu_features (&GLRO(dl_powerpc_cpu_features)); } #endif diff --git a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c index ebe9434052..fc26dd0e17 100644 --- a/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c +++ b/sysdeps/powerpc/powerpc64/multiarch/ifunc-impl-list.c @@ -17,6 +17,7 @@ <https://www.gnu.org/licenses/>. */ #include <assert.h> +#include <cpu-features.h> #include <string.h> #include <wchar.h> #include <ldsodefs.h> @@ -27,9 +28,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, size_t max) { size_t i = max; - - unsigned long int hwcap = GLRO(dl_hwcap); - unsigned long int hwcap2 = GLRO(dl_hwcap2); + const struct cpu_features *features = &GLRO(dl_powerpc_cpu_features); + unsigned long int hwcap = features->hwcap; + unsigned long int hwcap2 = features->hwcap2; #ifdef SHARED int cacheline_size = GLRO(dl_cache_line_size); #endif
From: Mahesh Bodapati <mahesh.bodapati@ibm.com> 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 tunable only handles the features which are really used in the IFUNC selection. All others are ignored as the values are only used inside glibc. --- manual/tunables.texi | 5 +- sysdeps/powerpc/cpu-features.c | 93 ++++++++++++++++++- sysdeps/powerpc/cpu-features.h | 57 ++++++++++++ sysdeps/powerpc/dl-tunables.list | 3 + sysdeps/powerpc/hwcapinfo.c | 4 + .../powerpc32/power4/multiarch/init-arch.h | 10 +- sysdeps/powerpc/powerpc64/dl-machine.h | 2 - .../powerpc64/multiarch/ifunc-impl-list.c | 7 +- 8 files changed, 170 insertions(+), 11 deletions(-)