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/*
* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_CPUFEATURE_H
#define __ASM_CPUFEATURE_H
#include <asm/hwcap.h>
#include <asm/sysreg.h>
/*
* In the arm64 world (as in the ARM world), elf_hwcap is used both internally
* in the kernel and for user space to keep track of which optional features
* are supported by the current system. So let's map feature 'x' to HWCAP_x.
* Note that HWCAP_x constants are bit fields so we need to take the log.
*/
#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap))
#define cpu_feature(x) ilog2(HWCAP_ ## x)
#define ARM64_WORKAROUND_CLEAN_CACHE 0
#define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE 1
#define ARM64_WORKAROUND_845719 2
#define ARM64_HAS_SYSREG_GIC_CPUIF 3
#define ARM64_HAS_PAN 4
#define ARM64_HAS_LSE_ATOMICS 5
#define ARM64_WORKAROUND_CAVIUM_23154 6
#define ARM64_WORKAROUND_834220 7
#define ARM64_HAS_NO_HW_PREFETCH 8
#define ARM64_WORKAROUND_CAVIUM_27456 9
#define ARM64_HAS_32BIT_EL0 10
#define ARM64_NCAPS 11
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
/* CPU feature register tracking */
enum ftr_type {
FTR_EXACT, /* Use a predefined safe value */
FTR_LOWER_SAFE, /* Smaller value is safe */
FTR_HIGHER_SAFE, /* Bigger value is safe */
FTR_HIGHER_OR_ZERO_SAFE, /* Bigger value is safe, but 0 is biggest */
};
#define FTR_STRICT true /* SANITY check strict matching required */
#define FTR_NONSTRICT false /* SANITY check ignored */
#define FTR_SIGNED true /* Value should be treated as signed */
#define FTR_UNSIGNED false /* Value should be treated as unsigned */
struct arm64_ftr_bits {
bool sign; /* Value is signed ? */
bool strict; /* CPU Sanity check: strict matching required ? */
enum ftr_type type;
u8 shift;
u8 width;
s64 safe_val; /* safe value for discrete features */
};
/*
* @arm64_ftr_reg - Feature register
* @strict_mask Bits which should match across all CPUs for sanity.
* @sys_val Safe value across the CPUs (system view)
*/
struct arm64_ftr_reg {
u32 sys_id;
const char *name;
u64 strict_mask;
u64 sys_val;
struct arm64_ftr_bits *ftr_bits;
};
struct arm64_cpu_capabilities {
const char *desc;
u16 capability;
bool (*matches)(const struct arm64_cpu_capabilities *);
int (*enable)(void *); /* Called on all active CPUs */
union {
struct { /* To be used for erratum handling only */
u32 midr_model;
u32 midr_range_min, midr_range_max;
};
struct { /* Feature register checking */
u32 sys_reg;
u8 field_pos;
u8 min_field_value;
u8 hwcap_type;
bool sign;
unsigned long hwcap;
};
};
};
extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
static inline bool cpu_have_feature(unsigned int num)
{
return elf_hwcap & (1UL << num);
}
static inline bool cpus_have_cap(unsigned int num)
{
if (num >= ARM64_NCAPS)
return false;
return test_bit(num, cpu_hwcaps);
}
static inline void cpus_set_cap(unsigned int num)
{
if (num >= ARM64_NCAPS)
pr_warn("Attempt to set an illegal CPU capability (%d >= %d)\n",
num, ARM64_NCAPS);
else
__set_bit(num, cpu_hwcaps);
}
static inline int __attribute_const__
cpuid_feature_extract_signed_field_width(u64 features, int field, int width)
{
return (s64)(features << (64 - width - field)) >> (64 - width);
}
static inline int __attribute_const__
cpuid_feature_extract_signed_field(u64 features, int field)
{
return cpuid_feature_extract_signed_field_width(features, field, 4);
}
static inline unsigned int __attribute_const__
cpuid_feature_extract_unsigned_field_width(u64 features, int field, int width)
{
return (u64)(features << (64 - width - field)) >> (64 - width);
}
static inline unsigned int __attribute_const__
cpuid_feature_extract_unsigned_field(u64 features, int field)
{
return cpuid_feature_extract_unsigned_field_width(features, field, 4);
}
static inline u64 arm64_ftr_mask(struct arm64_ftr_bits *ftrp)
{
return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift);
}
static inline int __attribute_const__
cpuid_feature_extract_field(u64 features, int field, bool sign)
{
return (sign) ?
cpuid_feature_extract_signed_field(features, field) :
cpuid_feature_extract_unsigned_field(features, field);
}
static inline s64 arm64_ftr_value(struct arm64_ftr_bits *ftrp, u64 val)
{
return (s64)cpuid_feature_extract_field(val, ftrp->shift, ftrp->sign);
}
static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
{
return cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_BIGENDEL_SHIFT) == 0x1 ||
cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_BIGENDEL0_SHIFT) == 0x1;
}
void __init setup_cpu_features(void);
void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info);
void check_local_cpu_errata(void);
#ifdef CONFIG_HOTPLUG_CPU
void verify_local_cpu_capabilities(void);
#else
static inline void verify_local_cpu_capabilities(void)
{
}
#endif
u64 read_system_reg(u32 id);
static inline bool cpu_supports_mixed_endian_el0(void)
{
return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
}
static inline bool system_supports_32bit_el0(void)
{
return cpus_have_cap(ARM64_HAS_32BIT_EL0);
}
static inline bool system_supports_mixed_endian_el0(void)
{
return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
}
#endif /* __ASSEMBLY__ */
#endif
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