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 #define ARM64_WORKAROUND_845719 2 27 #define ARM64_HAS_SYSREG_GIC_CPUIF 3 28 29 #define ARM64_NCAPS 4 30 31 #ifndef __ASSEMBLY__ 32 33 struct arm64_cpu_capabilities { 34 const char *desc; 35 u16 capability; 36 bool (*matches)(const struct arm64_cpu_capabilities *); 37 union { 38 struct { /* To be used for erratum handling only */ 39 u32 midr_model; 40 u32 midr_range_min, midr_range_max; 41 }; 42 43 struct { /* Feature register checking */ 44 u64 register_mask; 45 u64 register_value; 46 }; 47 }; 48 }; 49 50 extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); 51 52 static inline bool cpu_have_feature(unsigned int num) 53 { 54 return elf_hwcap & (1UL << num); 55 } 56 57 static inline bool cpus_have_cap(unsigned int num) 58 { 59 if (num >= ARM64_NCAPS) 60 return false; 61 return test_bit(num, cpu_hwcaps); 62 } 63 64 static inline void cpus_set_cap(unsigned int num) 65 { 66 if (num >= ARM64_NCAPS) 67 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n", 68 num, ARM64_NCAPS); 69 else 70 __set_bit(num, cpu_hwcaps); 71 } 72 73 void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps, 74 const char *info); 75 void check_local_cpu_errata(void); 76 void check_local_cpu_features(void); 77 bool cpu_supports_mixed_endian_el0(void); 78 bool system_supports_mixed_endian_el0(void); 79 80 #endif /* __ASSEMBLY__ */ 81 82 #endif 83