glibc/sysdeps/s390/dl-procinfo.c
Stefan Liebler 41f67ccbe9 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.
2023-02-07 09:19:27 +01:00

63 lines
1.9 KiB
C

/* Data for s390 version of processor capability information.
Copyright (C) 2006-2023 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/>. */
/* The hwcap and platform strings are now in
sysdeps/s390/dl-procinfo-s390.c. */
/* 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