@@ -486,7 +486,11 @@ enable CPU/ARCH feature @code{yyy}, disable CPU/ARCH feature @code{xxx}
and @code{zzz} where the feature name is case-sensitive and has to match
the ones in @code{sysdeps/x86/include/cpu-features.h}.
-This tunable is specific to i386 and x86-64.
+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.
@end deftp
@deftp Tunable glibc.cpu.cached_memopt
new file mode 100644
@@ -0,0 +1,239 @@
+/* Initialize cpu feature data. s390x version.
+ 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <cpu-features.h>
+
+#if HAVE_TUNABLES
+# include <elf/dl-tunables.h>
+# include <ifunc-memcmp.h>
+# include <string.h>
+extern __typeof (memcmp) MEMCMP_DEFAULT;
+#endif
+
+#if HAVE_TUNABLES
+# define S390_COPY_CPU_FEATURES(SRC_PTR, DEST_PTR) \
+ (DEST_PTR)->hwcap = (SRC_PTR)->hwcap; \
+ (DEST_PTR)->stfle_bits[0] = (SRC_PTR)->stfle_bits[0];
+
+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 STFLE-bits. But in
+ some scenarios it is useful to adjust this selection.
+
+ The environment variable:
+
+ GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,zzz,....
+
+ can be used to enable HWCAP/STFLE feature yyy, disable HWCAP/STFLE feature
+ xxx, where the feature name is case-sensitive and has to match the ones
+ used below. Furthermore, the ARCH-level zzz can be used to set various
+ HWCAP/STFLE features at once. */
+
+ /* Copy the features from dl_s390_cpu_features, which contains the features
+ provided by AT_HWCAP and stfle-instruction. */
+ struct cpu_features *cpu_features = &GLRO(dl_s390_cpu_features);
+ struct cpu_features cpu_features_orig;
+ S390_COPY_CPU_FEATURES (cpu_features, &cpu_features_orig);
+ struct cpu_features cpu_features_curr;
+ S390_COPY_CPU_FEATURES (cpu_features, &cpu_features_curr);
+
+ const char *token = valp->strval;
+ do
+ {
+ const char *token_end, *feature;
+ bool disable;
+ size_t token_len;
+ size_t 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;
+ }
+
+ /* Handle only the features here which are really used in the
+ IFUNC-resolvers. All others are ignored as the values are only used
+ inside glibc. */
+ bool reset_features = false;
+ unsigned long int hwcap_mask = 0UL;
+ unsigned long long stfle_bits0_mask = 0ULL;
+
+ if ((*feature == 'z' || *feature == 'a'))
+ {
+ if ((feature_len == 5 && *feature == 'z'
+ && MEMCMP_DEFAULT (feature, "zEC12", 5) == 0)
+ || (feature_len == 6 && *feature == 'a'
+ && MEMCMP_DEFAULT (feature, "arch10", 6) == 0))
+ {
+ reset_features = true;
+ disable = true;
+ hwcap_mask = HWCAP_S390_VXRS | HWCAP_S390_VXRS_EXT
+ | HWCAP_S390_VXRS_EXT2;
+ stfle_bits0_mask = S390_STFLE_MASK_ARCH13_MIE3;
+ }
+ else if ((feature_len == 3 && *feature == 'z'
+ && MEMCMP_DEFAULT (feature, "z13", 3) == 0)
+ || (feature_len == 6 && *feature == 'a'
+ && MEMCMP_DEFAULT (feature, "arch11", 6) == 0))
+ {
+ reset_features = true;
+ disable = true;
+ hwcap_mask = HWCAP_S390_VXRS_EXT | HWCAP_S390_VXRS_EXT2;
+ stfle_bits0_mask = S390_STFLE_MASK_ARCH13_MIE3;
+ }
+ else if ((feature_len == 3 && *feature == 'z'
+ && MEMCMP_DEFAULT (feature, "z14", 3) == 0)
+ || (feature_len == 6 && *feature == 'a'
+ && MEMCMP_DEFAULT (feature, "arch12", 6) == 0))
+ {
+ reset_features = true;
+ disable = true;
+ hwcap_mask = HWCAP_S390_VXRS_EXT2;
+ stfle_bits0_mask = S390_STFLE_MASK_ARCH13_MIE3;
+ }
+ else if ((feature_len == 3 && *feature == 'z'
+ && (MEMCMP_DEFAULT (feature, "z15", 3) == 0
+ || MEMCMP_DEFAULT (feature, "z16", 3) == 0))
+ || (feature_len == 6
+ && (MEMCMP_DEFAULT (feature, "arch13", 6) == 0
+ || MEMCMP_DEFAULT (feature, "arch14", 6) == 0)))
+ {
+ /* For z15 or newer we don't have to disable something,
+ but we have to reset to the original values. */
+ reset_features = true;
+ }
+ }
+ else if (*feature == 'H')
+ {
+ if (feature_len == 15
+ && MEMCMP_DEFAULT (feature, "HWCAP_S390_VXRS", 15) == 0)
+ {
+ hwcap_mask = HWCAP_S390_VXRS;
+ if (disable)
+ hwcap_mask |= HWCAP_S390_VXRS_EXT | HWCAP_S390_VXRS_EXT2;
+ }
+ else if (feature_len == 19
+ && MEMCMP_DEFAULT (feature, "HWCAP_S390_VXRS_EXT", 19) == 0)
+ {
+ hwcap_mask = HWCAP_S390_VXRS_EXT;
+ if (disable)
+ hwcap_mask |= HWCAP_S390_VXRS_EXT2;
+ else
+ hwcap_mask |= HWCAP_S390_VXRS;
+ }
+ else if (feature_len == 20
+ && MEMCMP_DEFAULT (feature, "HWCAP_S390_VXRS_EXT2", 20) == 0)
+ {
+ hwcap_mask = HWCAP_S390_VXRS_EXT2;
+ if (!disable)
+ hwcap_mask |= HWCAP_S390_VXRS | HWCAP_S390_VXRS_EXT;
+ }
+ }
+ else if (*feature == 'S')
+ {
+ if (feature_len == 10
+ && MEMCMP_DEFAULT (feature, "STFLE_MIE3", 10) == 0)
+ {
+ stfle_bits0_mask = S390_STFLE_MASK_ARCH13_MIE3;
+ }
+ }
+
+ /* Perform the actions determined above. */
+ if (reset_features)
+ {
+ S390_COPY_CPU_FEATURES (&cpu_features_orig, &cpu_features_curr);
+ }
+
+ if (hwcap_mask != 0UL)
+ {
+ if (disable)
+ cpu_features_curr.hwcap &= ~hwcap_mask;
+ else
+ cpu_features_curr.hwcap |= hwcap_mask;
+ }
+
+ if (stfle_bits0_mask != 0ULL)
+ {
+ if (disable)
+ cpu_features_curr.stfle_bits[0] &= ~stfle_bits0_mask;
+ else
+ cpu_features_curr.stfle_bits[0] |= stfle_bits0_mask;
+ }
+
+ /* Jump over current token ... */
+ token += token_len;
+
+ /* ... and skip token separator for next round. */
+ if (*token == ',') token++;
+ }
+ while (*token != '\0');
+
+ /* Copy back the features after checking that no unsupported features were
+ enabled by user. */
+ cpu_features->hwcap = cpu_features_curr.hwcap & cpu_features_orig.hwcap;
+ cpu_features->stfle_bits[0] = cpu_features_curr.stfle_bits[0]
+ & cpu_features_orig.stfle_bits[0];
+}
+#endif
+
+static inline void
+init_cpu_features (struct cpu_features *cpu_features)
+{
+ /* Fill cpu_features as passed by kernel and machine. */
+ cpu_features->hwcap = GLRO(dl_hwcap);
+
+ /* We want just 1 double word to be returned. */
+ if (__glibc_likely ((cpu_features->hwcap & HWCAP_S390_STFLE)
+ && (cpu_features->hwcap & HWCAP_S390_ZARCH)
+ && (cpu_features->hwcap & HWCAP_S390_HIGH_GPRS)))
+ {
+ register unsigned long reg0 __asm__("0") = 0;
+ __asm__ __volatile__(".machine push" "\n\t"
+ ".machine \"z9-109\"" "\n\t"
+ ".machinemode \"zarch_nohighgprs\"\n\t"
+ "stfle %0" "\n\t"
+ ".machine pop" "\n"
+ : "=QS" (cpu_features->stfle_bits[0]),
+ "+d" (reg0)
+ : : "cc");
+ }
+ else
+ {
+ cpu_features->stfle_bits[0] = 0ULL;
+ }
+
+#if HAVE_TUNABLES
+ TUNABLE_GET (glibc, cpu, hwcaps, tunable_val_t *, TUNABLE_CALLBACK (set_hwcaps));
+#endif
+}
new file mode 100644
@@ -0,0 +1,46 @@
+/* Initialize cpu feature data. s390x version.
+ Copyright (C) 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
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef __CPU_FEATURES_S390X_H
+# define __CPU_FEATURES_S390X_H
+
+#define S390_STFLE_BITS_Z10 34 /* General instructions extension */
+#define S390_STFLE_BITS_Z196 45 /* Distinct operands, pop ... */
+#define S390_STFLE_BITS_ARCH13_MIE3 61 /* Miscellaneous-Instruction-Extensions
+ Facility 3, e.g. mvcrl. */
+
+#define S390_STFLE_MASK_ARCH13_MIE3 (1ULL << (63 - S390_STFLE_BITS_ARCH13_MIE3))
+
+
+#define S390_IS_ARCH13_MIE3(STFLE_BITS_ARRAY) \
+ (((STFLE_BITS_ARRAY)[0] & S390_STFLE_MASK_ARCH13_MIE3) != 0)
+
+#define S390_IS_Z196(STFLE_BITS_ARRAY) \
+ (((STFLE_BITS_ARRAY)[0] & (1ULL << (63 - S390_STFLE_BITS_Z196))) != 0)
+
+#define S390_IS_Z10(STFLE_BITS_ARRAY) \
+ (((STFLE_BITS_ARRAY)[0] & (1ULL << (63 - S390_STFLE_BITS_Z10))) != 0)
+
+struct cpu_features
+{
+ unsigned long int hwcap;
+ unsigned long int __reserved_hwcap2;
+ unsigned long long stfle_bits[3];
+ unsigned long long __reserved[11];
+};
+
+#endif /* __CPU_FEATURES_S390X_H */
@@ -21,5 +21,42 @@
/* Needed by sysdeps/unix/sysv/linux/dl-vdso-setup.c (as included from
sysdeps/generic/ldsodefs.h). */
+
+/* All the #ifdefs in the definitions are quite irritating but
+ necessary if we want to avoid duplicating the information. There
+ are three different modes:
+
+ - PROCINFO_DECL is defined. This means we are only interested in
+ declarations.
+
+ - PROCINFO_DECL is not defined:
+
+ + if SHARED is defined the file is included in an array
+ initializer. The .element = { ... } syntax is needed.
+
+ + if SHARED is not defined a normal array initialization is
+ needed.
+ */
+
+#ifndef PROCINFO_CLASS
+# define PROCINFO_CLASS
+#endif
+
+#if !IS_IN (ldconfig)
+# if !defined PROCINFO_DECL && defined SHARED
+ ._dl_s390_cpu_features
+# else
+PROCINFO_CLASS struct cpu_features _dl_s390_cpu_features
+# endif
+# ifndef PROCINFO_DECL
+= { }
+# endif
+# if !defined SHARED || defined PROCINFO_DECL
+;
+# else
+,
+# endif
+#endif
+
#undef PROCINFO_DECL
#undef PROCINFO_CLASS
new file mode 100644
@@ -0,0 +1,25 @@
+# s390 specific tunables.
+# 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
+# <https://www.gnu.org/licenses/>.
+
+glibc {
+ cpu {
+ hwcaps {
+ type: STRING
+ }
+ }
+}
@@ -20,6 +20,7 @@
#define _S390_LDSODEFS_H 1
#include <elf.h>
+#include <cpu-features.h>
struct La_s390_32_regs;
struct La_s390_32_retval;
new file mode 100644
@@ -0,0 +1,33 @@
+/* Override csu/libc-start.c on s390x.
+ 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
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef SHARED
+
+/* Mark symbols hidden in static PIE for early self relocation to work. */
+# if BUILD_PIE_DEFAULT
+# pragma GCC visibility push(hidden)
+# endif
+# include <ldsodefs.h>
+# include <cpu-features.c>
+
+extern struct cpu_features _dl_s390_cpu_features;
+
+# define ARCH_INIT_CPU_FEATURES() init_cpu_features (&_dl_s390_cpu_features)
+
+#endif
+#include <csu/libc-start.c>
@@ -19,6 +19,7 @@
#include <assert.h>
#include <string.h>
#include <wchar.h>
+#include <cpu-features.h>
#include <ifunc-impl-list.h>
#include <ifunc-resolve.h>
#include <ifunc-memset.h>
@@ -78,14 +79,10 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
size_t i __attribute__ ((unused)) = max;
/* Get hardware information. */
- unsigned long int dl_hwcap = GLRO (dl_hwcap);
- unsigned long long stfle_bits = 0ULL;
- if ((dl_hwcap & HWCAP_S390_STFLE)
- && (dl_hwcap & HWCAP_S390_ZARCH)
- && (dl_hwcap & HWCAP_S390_HIGH_GPRS))
- {
- S390_STORE_STFLE (stfle_bits);
- }
+ const struct cpu_features *features = &GLRO(dl_s390_cpu_features);
+ unsigned long int dl_hwcap = features->hwcap;
+ const unsigned long long * __attribute__((unused)) stfle_bits
+ = features->stfle_bits;
#if HAVE_MEMSET_IFUNC
IFUNC_IMPL (i, name, memset,
@@ -19,42 +19,17 @@
#include <unistd.h>
#include <dl-procinfo.h>
+#include <cpu-features.h>
-#define S390_STFLE_BITS_Z10 34 /* General instructions extension */
-#define S390_STFLE_BITS_Z196 45 /* Distinct operands, pop ... */
-#define S390_STFLE_BITS_ARCH13_MIE3 61 /* Miscellaneous-Instruction-Extensions
- Facility 3, e.g. mvcrl. */
-
-#define S390_IS_ARCH13_MIE3(STFLE_BITS) \
- ((STFLE_BITS & (1ULL << (63 - S390_STFLE_BITS_ARCH13_MIE3))) != 0)
-
-#define S390_IS_Z196(STFLE_BITS) \
- ((STFLE_BITS & (1ULL << (63 - S390_STFLE_BITS_Z196))) != 0)
-
-#define S390_IS_Z10(STFLE_BITS) \
- ((STFLE_BITS & (1ULL << (63 - S390_STFLE_BITS_Z10))) != 0)
-
-#define S390_STORE_STFLE(STFLE_BITS) \
- /* We want just 1 double word to be returned. */ \
- register unsigned long reg0 __asm__("0") = 0; \
- \
- __asm__ __volatile__(".machine push" "\n\t" \
- ".machine \"z9-109\"" "\n\t" \
- ".machinemode \"zarch_nohighgprs\"\n\t" \
- "stfle %0" "\n\t" \
- ".machine pop" "\n" \
- : "=QS" (STFLE_BITS), "+d" (reg0) \
- : : "cc");
#define s390_libc_ifunc_expr_stfle_init() \
- unsigned long long stfle_bits = 0ULL; \
- if (__glibc_likely ((hwcap & HWCAP_S390_STFLE) \
- && (hwcap & HWCAP_S390_ZARCH) \
- && (hwcap & HWCAP_S390_HIGH_GPRS))) \
- { \
- S390_STORE_STFLE (stfle_bits); \
- }
+ const unsigned long long *stfle_bits = features->stfle_bits;
+
+#define s390_libc_ifunc_expr_init() \
+ const struct cpu_features *features = &GLRO(dl_s390_cpu_features); \
+ /* The hwcap from kernel is passed as argument, but we \
+ explicitly use the hwcaps from cpu-features struct. */ \
+ hwcap = features->hwcap;
-#define s390_libc_ifunc_expr_init()
#define s390_libc_ifunc_expr(TYPE_FUNC, FUNC, EXPR) \
__ifunc (TYPE_FUNC, FUNC, EXPR, unsigned long int hwcap, \
s390_libc_ifunc_expr_init);
@@ -28,6 +28,9 @@
#include <dl-irel.h>
#include <dl-static-tls.h>
#include <dl-machine-rel.h>
+#include <cpu-features.c>
+
+#define ELF_MACHINE_IRELATIVE R_390_IRELATIVE
/* This is an older, now obsolete value. */
#define EM_S390_OLD 0xA390
@@ -242,6 +245,12 @@ dl_platform_init (void)
if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
/* Avoid an empty string which would disturb us. */
GLRO(dl_platform) = NULL;
+
+#ifdef SHARED
+ /* init_cpu_features has been called early from __libc_start_main in
+ static executable. */
+ init_cpu_features (&GLRO(dl_s390_cpu_features));
+#endif
}
static inline Elf32_Addr
@@ -29,6 +29,7 @@
#include <dl-irel.h>
#include <dl-static-tls.h>
#include <dl-machine-rel.h>
+#include <cpu-features.c>
#define ELF_MACHINE_IRELATIVE R_390_IRELATIVE
@@ -220,6 +221,13 @@ dl_platform_init (void)
if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
/* Avoid an empty string which would disturb us. */
GLRO(dl_platform) = NULL;
+
+#ifdef SHARED
+ /* init_cpu_features has been called early from __libc_start_main in
+ static executable. */
+ init_cpu_features (&GLRO(dl_s390_cpu_features));
+#endif
+
}
static inline Elf64_Addr
@@ -18,6 +18,7 @@
#include <unistd.h>
#include <dl-procinfo.h>
+#include <cpu-features.h>
static long int linux_sysconf (int name);
@@ -44,12 +45,14 @@ get_cache_info (int level, int attr, int type)
|| type < CACHE_TYPE_DATA || type > CACHE_TYPE_INSTRUCTION)
return 0L;
+ const struct cpu_features *features = &GLRO(dl_s390_cpu_features);
+
/* Check if ecag-instruction is available.
ecag - extract CPU attribute (only in zarch; arch >= z10; in as 2.24) */
- if (!(GLRO (dl_hwcap) & HWCAP_S390_STFLE)
+ if (!(features->hwcap & HWCAP_S390_STFLE)
#if !defined __s390x__
- || !(GLRO (dl_hwcap) & HWCAP_S390_ZARCH)
- || !(GLRO (dl_hwcap) & HWCAP_S390_HIGH_GPRS)
+ || !(features->hwcap & HWCAP_S390_ZARCH)
+ || !(features->hwcap & HWCAP_S390_HIGH_GPRS)
#endif /* !__s390x__ */
)
{
@@ -62,25 +65,7 @@ get_cache_info (int level, int attr, int type)
return 0L;
}
- /* Store facility list and check for z10.
- (see ifunc-resolver for details) */
- register unsigned long reg0 __asm__("0") = 0;
-#ifdef __s390x__
- unsigned long stfle_bits;
-# define STFLE_Z10_MASK (1UL << (63 - 34))
-#else
- unsigned long long stfle_bits;
-# define STFLE_Z10_MASK (1ULL << (63 - 34))
-#endif /* !__s390x__ */
- __asm__ __volatile__(".machine push" "\n\t"
- ".machinemode \"zarch_nohighgprs\"\n\t"
- ".machine \"z9-109\"" "\n\t"
- "stfle %0" "\n\t"
- ".machine pop" "\n"
- : "=QS" (stfle_bits), "+d" (reg0)
- : : "cc");
-
- if (!(stfle_bits & STFLE_Z10_MASK))
+ if (!S390_IS_Z10 (features->stfle_bits))
{
/* We are at least on a z9 machine.
Return 256byte for LINESIZE for L1 d/i-cache,