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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Copyright (C) 2017 Linaro Ltd. <[email protected]>
- */
- #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
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