/* * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #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); }Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ard Biesheuvel | 32 | 100.00% | 1 | 100.00% |
| Total | 32 | 100.00% | 1 | 100.00% |
| Person | Tokens | Prop | Commits | CommitProp |
| Ard Biesheuvel | 73 | 100.00% | 1 | 100.00% |
| Total | 73 | 100.00% | 1 | 100.00% |