cregit-Linux how code gets into the kernel

Release 4.14 arch/arm64/include/asm/cpufeature.h

/*
 * 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/cpucaps.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)

#ifndef __ASSEMBLY__

#include <linux/bug.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>

/*
 * CPU feature register tracking
 *
 * The safe value of a CPUID feature field is dependent on the implications
 * of the values assigned to it by the architecture. Based on the relationship
 * between the values, the features are classified into 3 types - LOWER_SAFE,
 * HIGHER_SAFE and EXACT.
 *
 * The lowest value of all the CPUs is chosen for LOWER_SAFE and highest
 * for HIGHER_SAFE. It is expected that all CPUs have the same value for
 * a field when EXACT is specified, failing which, the safe value specified
 * in the table is chosen.
 */


enum ftr_type {
	
FTR_EXACT,	/* Use a predefined safe value */
	
FTR_LOWER_SAFE,	/* Smaller value is safe */
	
FTR_HIGHER_SAFE,/* Bigger value is safe */
};


#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 */


#define FTR_VISIBLE	true	
/* Feature visible to the user space */

#define FTR_HIDDEN	false	
/* Feature is hidden from the user */


struct arm64_ftr_bits {
	
bool		sign;	/* Value is signed ? */
	
bool		visible;
	
bool		strict;	/* CPU Sanity check: strict matching required ? */
	
enum ftr_type	type;
	
u8		shift;
	
u8		width;
	
s64		safe_val; /* safe value for FTR_EXACT 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 {
	
const char			*name;
	
u64				strict_mask;
	
u64				user_mask;
	
u64				sys_val;
	
u64				user_val;
	
const struct arm64_ftr_bits	*ftr_bits;
};

extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0;

/* scope of capability check */
enum {
	
SCOPE_SYSTEM,
	
SCOPE_LOCAL_CPU,
};


struct arm64_cpu_capabilities {
	
const char *desc;
	
u16 capability;
	
int def_scope;			/* default scope */
	
bool (*matches)(const struct arm64_cpu_capabilities *caps, int scope);
	
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);
extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
extern struct static_key_false arm64_const_caps_ready;

bool this_cpu_has_cap(unsigned int cap);


static inline bool cpu_have_feature(unsigned int num) { return elf_hwcap & (1UL << num); }

Contributors

PersonTokensPropCommitsCommitProp
Ard Biesheuvel20100.00%1100.00%
Total20100.00%1100.00%

/* System capability check for constant caps */
static inline bool __cpus_have_const_cap(int num) { if (num >= ARM64_NCAPS) return false; return static_branch_unlikely(&cpu_hwcap_keys[num]); }

Contributors

PersonTokensPropCommitsCommitProp
Andre Przywara1655.17%120.00%
Catalin Marinas1034.48%120.00%
Suzuki K. Poulose13.45%120.00%
Mark Rutland13.45%120.00%
Fabio Estevam13.45%120.00%
Total29100.00%5100.00%


static inline bool cpus_have_cap(unsigned int num) { if (num >= ARM64_NCAPS) return false; return test_bit(num, cpu_hwcaps); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose1967.86%150.00%
Andre Przywara932.14%150.00%
Total28100.00%2100.00%


static inline bool cpus_have_const_cap(int num) { if (static_branch_likely(&arm64_const_caps_ready)) return __cpus_have_const_cap(num); else return cpus_have_cap(num); }

Contributors

PersonTokensPropCommitsCommitProp
Mark Rutland31100.00%1100.00%
Total31100.00%1100.00%


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); } }

Contributors

PersonTokensPropCommitsCommitProp
Andre Przywara3284.21%133.33%
Catalin Marinas410.53%133.33%
Fabio Estevam25.26%133.33%
Total38100.00%3100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
James Morse3384.62%133.33%
Suzuki K. Poulose615.38%266.67%
Total39100.00%3100.00%


static inline int __attribute_const__ cpuid_feature_extract_signed_field(u64 features, int field) { return cpuid_feature_extract_signed_field_width(features, field, 4); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose2395.83%266.67%
James Morse14.17%133.33%
Total24100.00%3100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose40100.00%1100.00%
Total40100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose25100.00%1100.00%
Total25100.00%1100.00%


static inline u64 arm64_ftr_mask(const struct arm64_ftr_bits *ftrp) { return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose3294.12%133.33%
James Morse12.94%133.33%
Ard Biesheuvel12.94%133.33%
Total34100.00%3100.00%


static inline u64 arm64_ftr_reg_user_value(const struct arm64_ftr_reg *reg) { return (reg->user_val | (reg->sys_val & reg->user_mask)); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose30100.00%1100.00%
Total30100.00%1100.00%


static inline int __attribute_const__ cpuid_feature_extract_field_width(u64 features, int field, int width, bool sign) { return (sign) ? cpuid_feature_extract_signed_field_width(features, field, width) : cpuid_feature_extract_unsigned_field_width(features, field, width); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose2660.47%150.00%
Mark Rutland1739.53%150.00%
Total43100.00%2100.00%


static inline int __attribute_const__ cpuid_feature_extract_field(u64 features, int field, bool sign) { return cpuid_feature_extract_field_width(features, field, 4, sign); }

Contributors

PersonTokensPropCommitsCommitProp
Mark Rutland2275.86%150.00%
Suzuki K. Poulose724.14%150.00%
Total29100.00%2100.00%


static inline s64 arm64_ftr_value(const struct arm64_ftr_bits *ftrp, u64 val) { return (s64)cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width, ftrp->sign); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose3183.78%360.00%
Mark Rutland513.51%120.00%
Ard Biesheuvel12.70%120.00%
Total37100.00%5100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose2793.10%266.67%
James Morse26.90%133.33%
Total29100.00%3100.00%


static inline bool id_aa64pfr0_32bit_el0(u64 pfr0) { u32 val = cpuid_feature_extract_unsigned_field(pfr0, ID_AA64PFR0_EL0_SHIFT); return val == ID_AA64PFR0_EL0_32BIT_64BIT; }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose25100.00%1100.00%
Total25100.00%1100.00%

void __init setup_cpu_features(void); void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, const char *info); void enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps); void check_local_cpu_capabilities(void); void update_cpu_errata_workarounds(void); void __init enable_errata_workarounds(void); void verify_local_cpu_errata_workarounds(void); u64 read_sanitised_ftr_reg(u32 id);
static inline bool cpu_supports_mixed_endian_el0(void) { return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1)); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose18100.00%2100.00%
Total18100.00%2100.00%


static inline bool system_supports_32bit_el0(void) { return cpus_have_const_cap(ARM64_HAS_32BIT_EL0); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose15100.00%2100.00%
Total15100.00%2100.00%


static inline bool system_supports_mixed_endian_el0(void) { return id_aa64mmfr0_mixed_endian_el0(read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1)); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose1794.44%266.67%
Dave P Martin15.56%133.33%
Total18100.00%3100.00%


static inline bool system_supports_fpsimd(void) { return !cpus_have_const_cap(ARM64_HAS_NO_FPSIMD); }

Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose16100.00%1100.00%
Total16100.00%1100.00%


static inline bool system_uses_ttbr0_pan(void) { return IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN) && !cpus_have_const_cap(ARM64_HAS_PAN); }

Contributors

PersonTokensPropCommitsCommitProp
Catalin Marinas2095.24%150.00%
Mark Rutland14.76%150.00%
Total21100.00%2100.00%

#endif /* __ASSEMBLY__ */ #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Suzuki K. Poulose52856.96%2451.06%
Andre Przywara879.39%48.51%
Mark Rutland828.85%36.38%
Marc Zyngier768.20%36.38%
Ard Biesheuvel525.61%36.38%
James Morse485.18%48.51%
Catalin Marinas454.85%36.38%
Fabio Estevam40.43%12.13%
Will Deacon30.32%12.13%
Dave P Martin20.22%12.13%
Total927100.00%47100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.