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 <linux/jump_label.h>
14 #include <asm/hwcap.h>
15 #include <asm/sysreg.h>
18 * In the arm64 world (as in the ARM world), elf_hwcap is used both internally
19 * in the kernel and for user space to keep track of which optional features
20 * are supported by the current system. So let's map feature 'x' to HWCAP_x.
21 * Note that HWCAP_x constants are bit fields so we need to take the log.
24 #define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
25 #define cpu_feature(x) ilog2(HWCAP_ ## x)
27 #define ARM64_WORKAROUND_CLEAN_CACHE 0
28 #define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1
29 #define ARM64_WORKAROUND_845719 2
30 #define ARM64_HAS_SYSREG_GIC_CPUIF 3
31 #define ARM64_HAS_PAN 4
32 #define ARM64_HAS_LSE_ATOMICS 5
33 #define ARM64_WORKAROUND_CAVIUM_23154 6
34 #define ARM64_WORKAROUND_834220 7
35 #define ARM64_HAS_NO_HW_PREFETCH 8
36 #define ARM64_HAS_UAO 9
37 #define ARM64_ALT_PAN_NOT_UAO 10
38 #define ARM64_HAS_VIRT_HOST_EXTN 11
39 #define ARM64_WORKAROUND_CAVIUM_27456 12
40 #define ARM64_HAS_32BIT_EL0 13
41 #define ARM64_HYP_OFFSET_LOW 14
43 #define ARM64_NCAPS 15
47 #include <linux/kernel.h>
49 /* CPU feature register tracking */
51 FTR_EXACT
, /* Use a predefined safe value */
52 FTR_LOWER_SAFE
, /* Smaller value is safe */
53 FTR_HIGHER_SAFE
,/* Bigger value is safe */
56 #define FTR_STRICT true /* SANITY check strict matching required */
57 #define FTR_NONSTRICT false /* SANITY check ignored */
59 #define FTR_SIGNED true /* Value should be treated as signed */
60 #define FTR_UNSIGNED false /* Value should be treated as unsigned */
62 struct arm64_ftr_bits
{
63 bool sign
; /* Value is signed ? */
64 bool strict
; /* CPU Sanity check: strict matching required ? */
68 s64 safe_val
; /* safe value for discrete features */
72 * @arm64_ftr_reg - Feature register
73 * @strict_mask Bits which should match across all CPUs for sanity.
74 * @sys_val Safe value across the CPUs (system view)
76 struct arm64_ftr_reg
{
80 const struct arm64_ftr_bits
*ftr_bits
;
83 extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0
;
85 /* scope of capability check */
91 struct arm64_cpu_capabilities
{
94 int def_scope
; /* default scope */
95 bool (*matches
)(const struct arm64_cpu_capabilities
*caps
, int scope
);
96 void (*enable
)(void *); /* Called on all active CPUs */
98 struct { /* To be used for erratum handling only */
100 u32 midr_range_min
, midr_range_max
;
103 struct { /* Feature register checking */
114 extern DECLARE_BITMAP(cpu_hwcaps
, ARM64_NCAPS
);
115 extern struct static_key_false cpu_hwcap_keys
[ARM64_NCAPS
];
117 bool this_cpu_has_cap(unsigned int cap
);
119 static inline bool cpu_have_feature(unsigned int num
)
121 return elf_hwcap
& (1UL << num
);
124 static inline bool cpus_have_cap(unsigned int num
)
126 if (num
>= ARM64_NCAPS
)
128 if (__builtin_constant_p(num
))
129 return static_branch_unlikely(&cpu_hwcap_keys
[num
]);
131 return test_bit(num
, cpu_hwcaps
);
134 static inline void cpus_set_cap(unsigned int num
)
136 if (num
>= ARM64_NCAPS
) {
137 pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n",
140 __set_bit(num
, cpu_hwcaps
);
141 static_branch_enable(&cpu_hwcap_keys
[num
]);
145 static inline int __attribute_const__
146 cpuid_feature_extract_signed_field_width(u64 features
, int field
, int width
)
148 return (s64
)(features
<< (64 - width
- field
)) >> (64 - width
);
151 static inline int __attribute_const__
152 cpuid_feature_extract_signed_field(u64 features
, int field
)
154 return cpuid_feature_extract_signed_field_width(features
, field
, 4);
157 static inline unsigned int __attribute_const__
158 cpuid_feature_extract_unsigned_field_width(u64 features
, int field
, int width
)
160 return (u64
)(features
<< (64 - width
- field
)) >> (64 - width
);
163 static inline unsigned int __attribute_const__
164 cpuid_feature_extract_unsigned_field(u64 features
, int field
)
166 return cpuid_feature_extract_unsigned_field_width(features
, field
, 4);
169 static inline u64
arm64_ftr_mask(const struct arm64_ftr_bits
*ftrp
)
171 return (u64
)GENMASK(ftrp
->shift
+ ftrp
->width
- 1, ftrp
->shift
);
174 static inline int __attribute_const__
175 cpuid_feature_extract_field(u64 features
, int field
, bool sign
)
178 cpuid_feature_extract_signed_field(features
, field
) :
179 cpuid_feature_extract_unsigned_field(features
, field
);
182 static inline s64
arm64_ftr_value(const struct arm64_ftr_bits
*ftrp
, u64 val
)
184 return (s64
)cpuid_feature_extract_field(val
, ftrp
->shift
, ftrp
->sign
);
187 static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0
)
189 return cpuid_feature_extract_unsigned_field(mmfr0
, ID_AA64MMFR0_BIGENDEL_SHIFT
) == 0x1 ||
190 cpuid_feature_extract_unsigned_field(mmfr0
, ID_AA64MMFR0_BIGENDEL0_SHIFT
) == 0x1;
193 static inline bool id_aa64pfr0_32bit_el0(u64 pfr0
)
195 u32 val
= cpuid_feature_extract_unsigned_field(pfr0
, ID_AA64PFR0_EL0_SHIFT
);
197 return val
== ID_AA64PFR0_EL0_32BIT_64BIT
;
200 void __init
setup_cpu_features(void);
202 void update_cpu_capabilities(const struct arm64_cpu_capabilities
*caps
,
204 void enable_cpu_capabilities(const struct arm64_cpu_capabilities
*caps
);
205 void check_local_cpu_errata(void);
206 void __init
enable_errata_workarounds(void);
208 void verify_local_cpu_errata(void);
209 void verify_local_cpu_capabilities(void);
211 u64
read_system_reg(u32 id
);
213 static inline bool cpu_supports_mixed_endian_el0(void)
215 return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1
));
218 static inline bool system_supports_32bit_el0(void)
220 return cpus_have_cap(ARM64_HAS_32BIT_EL0
);
223 static inline bool system_supports_mixed_endian_el0(void)
225 return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1
));
228 #endif /* __ASSEMBLY__ */