mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 21:40:12 +00:00
73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/* Initialize CPU feature data. AArch64 version.
|
|
This file is part of the GNU C Library.
|
|
Copyright (C) 2017 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <cpu-features.h>
|
|
#include <sys/auxv.h>
|
|
#include <elf/dl-hwcaps.h>
|
|
|
|
#if HAVE_TUNABLES
|
|
struct cpu_list
|
|
{
|
|
const char *name;
|
|
uint64_t midr;
|
|
};
|
|
|
|
static struct cpu_list cpu_list[] = {
|
|
{"thunderxt88", 0x430F0A10},
|
|
{"generic", 0x0}
|
|
};
|
|
|
|
static uint64_t
|
|
get_midr_from_mcpu (const char *mcpu)
|
|
{
|
|
for (int i = 0; i < sizeof (cpu_list) / sizeof (struct cpu_list); i++)
|
|
if (tunable_is_name (mcpu, cpu_list[i].name) == 0)
|
|
return cpu_list[i].midr;
|
|
|
|
return UINT64_MAX;
|
|
}
|
|
#endif
|
|
|
|
static inline void
|
|
init_cpu_features (struct cpu_features *cpu_features)
|
|
{
|
|
uint64_t hwcap_mask = GET_HWCAP_MASK();
|
|
uint64_t hwcap = GLRO (dl_hwcap) & hwcap_mask;
|
|
|
|
register uint64_t midr = UINT64_MAX;
|
|
|
|
#if HAVE_TUNABLES
|
|
/* Get the tunable override. */
|
|
const char *mcpu = TUNABLE_GET (glibc, tune, cpu, const char *, NULL);
|
|
if (mcpu != NULL)
|
|
midr = get_midr_from_mcpu (mcpu);
|
|
#endif
|
|
|
|
/* If there was no useful tunable override, query the MIDR if the kernel
|
|
allows it. */
|
|
if (midr == UINT64_MAX)
|
|
{
|
|
if (hwcap & HWCAP_CPUID)
|
|
asm volatile ("mrs %0, midr_el1" : "=r"(midr));
|
|
else
|
|
midr = 0;
|
|
}
|
|
|
|
cpu_features->midr_el1 = midr;
|
|
}
|