1/* Initialize CPU feature data via IFUNC relocation.
2 Copyright (C) 2015-2023 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18
19#include <ldsodefs.h>
20
21#ifdef SHARED
22# include <cpu-features.c>
23# include <gcc-macros.h>
24
25/* NB: Normally, DL_PLATFORM_INIT calls init_cpu_features to initialize
26 CPU features in dynamic executable. But when loading ld.so inside of
27 static executable, DL_PLATFORM_INIT isn't called and IFUNC relocation
28 is used to call init_cpu_features. In static executable, it is called
29 once by IFUNC relocation. In dynamic executable, it is called twice
30 by DL_PLATFORM_INIT and by IFUNC relocation. */
31extern void __x86_cpu_features (void) attribute_hidden;
32void (*const __x86_cpu_features_p) (void) attribute_hidden
33 = __x86_cpu_features;
34
35void
36_dl_x86_init_cpu_features (void)
37{
38 struct cpu_features *cpu_features = __get_cpu_features ();
39 if (cpu_features->basic.kind == arch_kind_unknown)
40 {
41 init_cpu_features (cpu_features);
42
43# if IS_IN (rtld)
44 /* See isa-level.c. */
45# if defined GCCMACRO__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
46 && defined HAVE_X86_LAHF_SAHF && defined GCCMACRO__POPCNT__ \
47 && defined GCCMACRO__SSE3__ && defined GCCMACRO__SSSE3__ \
48 && defined GCCMACRO__SSE4_1__ && defined GCCMACRO__SSE4_2__
49 if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V2))
50 _dl_fatal_printf ("\
51Fatal glibc error: CPU does not support x86-64-v%d\n", 2);
52# if defined GCCMACRO__AVX__ && defined GCCMACRO__AVX2__ \
53 && defined GCCMACRO__F16C__ && defined GCCMACRO__FMA__ \
54 && defined GCCMACRO__LZCNT__ && defined HAVE_X86_MOVBE
55 if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V3))
56 _dl_fatal_printf ("\
57Fatal glibc error: CPU does not support x86-64-v%d\n", 3);
58# if defined GCCMACRO__AVX512F__ && defined GCCMACRO__AVX512BW__ \
59 && defined GCCMACRO__AVX512CD__ && defined GCCMACRO__AVX512DQ__ \
60 && defined GCCMACRO__AVX512VL__
61 if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V4))
62 _dl_fatal_printf ("\
63Fatal glibc error: CPU does not support x86-64-v%d\n", 4);
64# endif /* ISA level 4 */
65# endif /* ISA level 3 */
66# endif /* ISA level 2 */
67# endif /* IS_IN (rtld) */
68 }
69}
70
71__ifunc (__x86_cpu_features, __x86_cpu_features, NULL, void,
72 _dl_x86_init_cpu_features);
73#endif
74
75#undef _dl_x86_get_cpu_features
76
77const struct cpu_features *
78_dl_x86_get_cpu_features (void)
79{
80 return &GLRO(dl_x86_cpu_features);
81}
82