diff options
Diffstat (limited to 'util/compress/libdeflate/lib/arm/cpu_features.c')
| -rw-r--r-- | util/compress/libdeflate/lib/arm/cpu_features.c | 133 |
1 files changed, 0 insertions, 133 deletions
diff --git a/util/compress/libdeflate/lib/arm/cpu_features.c b/util/compress/libdeflate/lib/arm/cpu_features.c deleted file mode 100644 index 60b1be3ee..000000000 --- a/util/compress/libdeflate/lib/arm/cpu_features.c +++ /dev/null @@ -1,133 +0,0 @@ -/* - * arm/cpu_features.c - feature detection for ARM processors - * - * Copyright 2018 Eric Biggers - * - * Permission is hereby granted, free of charge, to any person - * obtaining a copy of this software and associated documentation - * files (the "Software"), to deal in the Software without - * restriction, including without limitation the rights to use, - * copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following - * conditions: - * - * The above copyright notice and this permission notice shall be - * included in all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, - * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES - * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND - * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT - * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, - * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR - * OTHER DEALINGS IN THE SOFTWARE. - */ - -/* - * ARM processors don't have a standard way for unprivileged programs to detect - * processor features. But, on Linux we can read the AT_HWCAP and AT_HWCAP2 - * values from /proc/self/auxv. - * - * Ideally we'd use the C library function getauxval(), but it's not guaranteed - * to be available: it was only added to glibc in 2.16, and in Android it was - * added to API level 18 for ARM and level 21 for AArch64. - */ - -#include "../cpu_features_common.h" /* must be included first */ -#include "cpu_features.h" - -#if ARM_CPU_FEATURES_ENABLED - -#include <errno.h> -#include <fcntl.h> -#include <string.h> -#include <unistd.h> - -#define AT_HWCAP 16 -#define AT_HWCAP2 26 - -volatile u32 _cpu_features = 0; - -static void scan_auxv(unsigned long *hwcap, unsigned long *hwcap2) -{ - int fd; - unsigned long auxbuf[32]; - int filled = 0; - int i; - - fd = open("/proc/self/auxv", O_RDONLY); - if (fd < 0) - return; - - for (;;) { - do { - int ret = read(fd, &((char *)auxbuf)[filled], - sizeof(auxbuf) - filled); - if (ret <= 0) { - if (ret < 0 && errno == EINTR) - continue; - goto out; - } - filled += ret; - } while (filled < 2 * sizeof(long)); - - i = 0; - do { - unsigned long type = auxbuf[i]; - unsigned long value = auxbuf[i + 1]; - - if (type == AT_HWCAP) - *hwcap = value; - else if (type == AT_HWCAP2) - *hwcap2 = value; - i += 2; - filled -= 2 * sizeof(long); - } while (filled >= 2 * sizeof(long)); - - memmove(auxbuf, &auxbuf[i], filled); - } -out: - close(fd); -} - -static const struct cpu_feature arm_cpu_feature_table[] = { - {ARM_CPU_FEATURE_NEON, "neon"}, - {ARM_CPU_FEATURE_PMULL, "pmull"}, - {ARM_CPU_FEATURE_CRC32, "crc32"}, -}; - -void setup_cpu_features(void) -{ - u32 features = 0; - unsigned long hwcap = 0; - unsigned long hwcap2 = 0; - - scan_auxv(&hwcap, &hwcap2); - -#ifdef __arm__ - STATIC_ASSERT(sizeof(long) == 4); - if (hwcap & (1 << 12)) /* HWCAP_NEON */ - features |= ARM_CPU_FEATURE_NEON; - if (hwcap2 & (1 << 1)) /* HWCAP2_PMULL */ - features |= ARM_CPU_FEATURE_PMULL; - if (hwcap2 & (1 << 4)) /* HWCAP2_CRC32 */ - features |= ARM_CPU_FEATURE_CRC32; -#else - STATIC_ASSERT(sizeof(long) == 8); - if (hwcap & (1 << 1)) /* HWCAP_ASIMD */ - features |= ARM_CPU_FEATURE_NEON; - if (hwcap & (1 << 4)) /* HWCAP_PMULL */ - features |= ARM_CPU_FEATURE_PMULL; - if (hwcap & (1 << 7)) /* HWCAP_CRC32 */ - features |= ARM_CPU_FEATURE_CRC32; -#endif - - disable_cpu_features_for_testing(&features, arm_cpu_feature_table, - ARRAY_LEN(arm_cpu_feature_table)); - - _cpu_features = features | ARM_CPU_FEATURES_KNOWN; -} - -#endif /* ARM_CPU_FEATURES_ENABLED */ |