linux/arch/arm64/include/asm/cpufeature.h
Will Deacon c739dc83a0 arm64: lse: rename ARM64_CPU_FEAT_LSE_ATOMICS for consistency
Other CPU features follow an 'ARM64_HAS_*' naming scheme, so do the same
for the LSE atomics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 15:28:54 +01:00

95 lines
2.3 KiB
C

/*
* 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>
/*
* 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_NCAPS 6
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
struct arm64_cpu_capabilities {
const char *desc;
u16 capability;
bool (*matches)(const struct arm64_cpu_capabilities *);
void (*enable)(void);
union {
struct { /* To be used for erratum handling only */
u32 midr_model;
u32 midr_range_min, midr_range_max;
};
struct { /* Feature register checking */
int field_pos;
int min_field_value;
};
};
};
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_field(u64 features,
int field)
{
return (s64)(features << (64 - 4 - field)) >> (64 - 4);
}
void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info);
void check_local_cpu_errata(void);
void check_local_cpu_features(void);
bool cpu_supports_mixed_endian_el0(void);
bool system_supports_mixed_endian_el0(void);
#endif /* __ASSEMBLY__ */
#endif