2 * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
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.
9 #ifndef __ASM_CPUFEATURE_H
10 #define __ASM_CPUFEATURE_H
12 #include <asm/hwcap.h>
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.
21 #define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
22 #define cpu_feature(x) ilog2(HWCAP_ ## x)
24 #define ARM64_WORKAROUND_CLEAN_CACHE 0
25 #define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1
26 #define ARM64_WORKAROUND_845719 2
32 struct arm64_cpu_capabilities {
35 bool (*matches)(const struct arm64_cpu_capabilities *);
37 struct { /* To be used for erratum handling only */
39 u32 midr_range_min, midr_range_max;
44 extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
46 static inline bool cpu_have_feature(unsigned int num)
48 return elf_hwcap & (1UL << num);
51 static inline bool cpus_have_cap(unsigned int num)
53 if (num >= ARM64_NCAPS)
55 return test_bit(num, cpu_hwcaps);
58 static inline void cpus_set_cap(unsigned int num)
60 if (num >= ARM64_NCAPS)
61 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n",
64 __set_bit(num, cpu_hwcaps);
67 void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
69 void check_local_cpu_errata(void);
70 void check_local_cpu_features(void);
71 bool cpu_supports_mixed_endian_el0(void);
72 bool system_supports_mixed_endian_el0(void);
74 #endif /* __ASSEMBLY__ */