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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/include/asm/cpufeature.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/include/asm/cpufeature.h')
-rw-r--r-- | arch/arm/include/asm/cpufeature.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm/include/asm/cpufeature.h b/arch/arm/include/asm/cpufeature.h new file mode 100644 index 000000000..16c161b3f --- /dev/null +++ b/arch/arm/include/asm/cpufeature.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> + */ + +#ifndef __ASM_CPUFEATURE_H +#define __ASM_CPUFEATURE_H + +#include <linux/log2.h> +#include <asm/hwcap.h> + +/* + * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number + * of optional CPU features it defines, ARM's CPU hardware capability bits have + * been distributed over separate elf_hwcap and elf_hwcap2 variables, each of + * which covers a subset of the available CPU features. + * + * Currently, only a few of those are suitable for automatic module loading + * (which is the primary use case of this facility) and those happen to be all + * covered by HWCAP2. So let's only cover those via the cpu_feature() + * convenience macro for now (which is used by module_cpu_feature_match()). + * However, all capabilities are exposed via the modalias, and can be matched + * using an explicit MODULE_DEVICE_TABLE() that uses __hwcap_feature() directly. + */ +#define MAX_CPU_FEATURES 64 +#define __hwcap_feature(x) ilog2(HWCAP_ ## x) +#define __hwcap2_feature(x) (32 + ilog2(HWCAP2_ ## x)) +#define cpu_feature(x) __hwcap2_feature(x) + +static inline bool cpu_have_feature(unsigned int num) +{ + return num < 32 ? elf_hwcap & BIT(num) : elf_hwcap2 & BIT(num - 32); +} + +#endif |