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>
13 #include <asm/sysreg.h>
16 * In the arm64 world (as in the ARM world), elf_hwcap is used both internally
17 * in the kernel and for user space to keep track of which optional features
18 * are supported by the current system. So let's map feature 'x' to HWCAP_x.
19 * Note that HWCAP_x constants are bit fields so we need to take the log.
22 #define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
23 #define cpu_feature(x) ilog2(HWCAP_ ## x)
25 #define ARM64_WORKAROUND_CLEAN_CACHE 0
26 #define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1
27 #define ARM64_WORKAROUND_845719 2
28 #define ARM64_HAS_SYSREG_GIC_CPUIF 3
29 #define ARM64_HAS_PAN 4
30 #define ARM64_HAS_LSE_ATOMICS 5
31 #define ARM64_WORKAROUND_CAVIUM_23154 6
32 #define ARM64_WORKAROUND_834220 7
33 #define ARM64_HAS_NO_HW_PREFETCH 8
34 #define ARM64_HAS_UAO 9
36 #define ARM64_NCAPS 10
40 #include <linux/kernel.h>
42 /* CPU feature register tracking */
44 FTR_EXACT
, /* Use a predefined safe value */
45 FTR_LOWER_SAFE
, /* Smaller value is safe */
46 FTR_HIGHER_SAFE
,/* Bigger value is safe */
49 #define FTR_STRICT true /* SANITY check strict matching required */
50 #define FTR_NONSTRICT false /* SANITY check ignored */
52 #define FTR_SIGNED true /* Value should be treated as signed */
53 #define FTR_UNSIGNED false /* Value should be treated as unsigned */
55 struct arm64_ftr_bits
{
56 bool sign
; /* Value is signed ? */
57 bool strict
; /* CPU Sanity check: strict matching required ? */
61 s64 safe_val
; /* safe value for discrete features */
65 * @arm64_ftr_reg - Feature register
66 * @strict_mask Bits which should match across all CPUs for sanity.
67 * @sys_val Safe value across the CPUs (system view)
69 struct arm64_ftr_reg
{
74 struct arm64_ftr_bits
*ftr_bits
;
77 struct arm64_cpu_capabilities
{
80 bool (*matches
)(const struct arm64_cpu_capabilities
*);
81 void (*enable
)(void *); /* Called on all active CPUs */
83 struct { /* To be used for erratum handling only */
85 u32 midr_range_min
, midr_range_max
;
88 struct { /* Feature register checking */
98 extern DECLARE_BITMAP(cpu_hwcaps
, ARM64_NCAPS
);
100 static inline bool cpu_have_feature(unsigned int num
)
102 return elf_hwcap
& (1UL << num
);
105 static inline bool cpus_have_cap(unsigned int num
)
107 if (num
>= ARM64_NCAPS
)
109 return test_bit(num
, cpu_hwcaps
);
112 static inline void cpus_set_cap(unsigned int num
)
114 if (num
>= ARM64_NCAPS
)
115 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n",
118 __set_bit(num
, cpu_hwcaps
);
121 static inline int __attribute_const__
122 cpuid_feature_extract_field_width(u64 features
, int field
, int width
)
124 return (s64
)(features
<< (64 - width
- field
)) >> (64 - width
);
127 static inline int __attribute_const__
128 cpuid_feature_extract_field(u64 features
, int field
)
130 return cpuid_feature_extract_field_width(features
, field
, 4);
133 static inline unsigned int __attribute_const__
134 cpuid_feature_extract_unsigned_field_width(u64 features
, int field
, int width
)
136 return (u64
)(features
<< (64 - width
- field
)) >> (64 - width
);
139 static inline unsigned int __attribute_const__
140 cpuid_feature_extract_unsigned_field(u64 features
, int field
)
142 return cpuid_feature_extract_unsigned_field_width(features
, field
, 4);
145 static inline u64
arm64_ftr_mask(struct arm64_ftr_bits
*ftrp
)
147 return (u64
)GENMASK(ftrp
->shift
+ ftrp
->width
- 1, ftrp
->shift
);
150 static inline s64
arm64_ftr_value(struct arm64_ftr_bits
*ftrp
, u64 val
)
153 cpuid_feature_extract_field_width(val
, ftrp
->shift
, ftrp
->width
) :
154 cpuid_feature_extract_unsigned_field_width(val
, ftrp
->shift
, ftrp
->width
);
157 static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0
)
159 return cpuid_feature_extract_field(mmfr0
, ID_AA64MMFR0_BIGENDEL_SHIFT
) == 0x1 ||
160 cpuid_feature_extract_field(mmfr0
, ID_AA64MMFR0_BIGENDEL0_SHIFT
) == 0x1;
163 void __init
setup_cpu_features(void);
165 void update_cpu_capabilities(const struct arm64_cpu_capabilities
*caps
,
167 void check_local_cpu_errata(void);
169 #ifdef CONFIG_HOTPLUG_CPU
170 void verify_local_cpu_capabilities(void);
172 static inline void verify_local_cpu_capabilities(void)
177 u64
read_system_reg(u32 id
);
179 static inline bool cpu_supports_mixed_endian_el0(void)
181 return id_aa64mmfr0_mixed_endian_el0(read_cpuid(SYS_ID_AA64MMFR0_EL1
));
184 static inline bool system_supports_mixed_endian_el0(void)
186 return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1
));
189 #endif /* __ASSEMBLY__ */