From 41f67ccbe92b4fd09e1062b383e55e407ae5bfa1 Mon Sep 17 00:00:00 2001 From: Stefan Liebler Date: Thu, 2 Feb 2023 14:57:50 +0100 Subject: S390: Influence hwcaps/stfle via GLIBC_TUNABLES. This patch enables the option to influence hwcaps and stfle bits used by the s390 specific ifunc-resolvers. The currently x86-specific tunable glibc.cpu.hwcaps is also used on s390x to achieve the task. In addition the user can also set a CPU arch-level like z13 instead of single HWCAP and STFLE features. Note that the tunable only handles the features which are really used in the IFUNC-resolvers. All others are ignored as the values are only used inside glibc. Thus we can influence: - HWCAP_S390_VXRS (z13) - HWCAP_S390_VXRS_EXT (z14) - HWCAP_S390_VXRS_EXT2 (z15) - STFLE_MIE3 (z15) The influenced hwcap/stfle-bits are stored in the s390-specific cpu_features struct which also contains reserved fields for future usage. The ifunc-resolvers and users of stfle bits are adjusted to use the information from cpu_features struct. On 31bit, the ELF_MACHINE_IRELATIVE macro is now also defined. Otherwise the new ifunc-resolvers segfaults as they depend on the not yet processed_rtld_global_ro@GLIBC_PRIVATE relocation. --- sysdeps/s390/cpu-features.h | 46 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 sysdeps/s390/cpu-features.h (limited to 'sysdeps/s390/cpu-features.h') diff --git a/sysdeps/s390/cpu-features.h b/sysdeps/s390/cpu-features.h new file mode 100644 index 0000000000..5e6b58f7c5 --- /dev/null +++ b/sysdeps/s390/cpu-features.h @@ -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 + . */ + +#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 */ -- cgit 1.4.1