| /* Initialize CPU feature data. AArch64 version. |
| This file is part of the GNU C Library. |
| Copyright (C) 2017-2018 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> |
| |
| #define DCZID_DZP_MASK (1 << 4) |
| #define DCZID_BS_MASK (0xf) |
| |
| #if HAVE_TUNABLES |
| struct cpu_list |
| { |
| const char *name; |
| uint64_t midr; |
| }; |
| |
| static struct cpu_list cpu_list[] = { |
| {"falkor", 0x510FC000}, |
| {"thunderxt88", 0x430F0A10}, |
| {"thunderx2t99", 0x431F0AF0}, |
| {"thunderx2t99p1", 0x420F5160}, |
| {"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 (strcmp (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; |
| |
| /* Check if ZVA is enabled. */ |
| unsigned dczid; |
| asm volatile ("mrs %0, dczid_el0" : "=r"(dczid)); |
| |
| if ((dczid & DCZID_DZP_MASK) == 0) |
| cpu_features->zva_size = 4 << (dczid & DCZID_BS_MASK); |
| } |