1 /* 2 * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 9 #ifndef __ASM_CPUFEATURE_H 10 #define __ASM_CPUFEATURE_H 11 12 #include <asm/hwcap.h> 13 14 /* 15 * In the arm64 world (as in the ARM world), elf_hwcap is used both internally 16 * in the kernel and for user space to keep track of which optional features 17 * are supported by the current system. So let's map feature 'x' to HWCAP_x. 18 * Note that HWCAP_x constants are bit fields so we need to take the log. 19 */ 20 21 #define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap)) 22 #define cpu_feature(x) ilog2(HWCAP_ ## x) 23 24 #define ARM64_WORKAROUND_CLEAN_CACHE 0 25 #define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1 26 27 #define ARM64_NCAPS 2 28 29 #ifndef __ASSEMBLY__ 30 31 extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); 32 33 static inline bool cpu_have_feature(unsigned int num) 34 { 35 return elf_hwcap & (1UL << num); 36 } 37 38 static inline bool cpus_have_cap(unsigned int num) 39 { 40 if (num >= ARM64_NCAPS) 41 return false; 42 return test_bit(num, cpu_hwcaps); 43 } 44 45 static inline void cpus_set_cap(unsigned int num) 46 { 47 if (num >= ARM64_NCAPS) 48 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n", 49 num, ARM64_NCAPS); 50 else 51 __set_bit(num, cpu_hwcaps); 52 } 53 54 void check_local_cpu_errata(void); 55 56 #endif /* __ASSEMBLY__ */ 57 58 #endif 59