linux/arch/arm64/include/asm/cpufeature.h
Linus Torvalds f4000cd997 arm64 updates for 4.10:
- struct thread_info moved off-stack (also touching
   include/linux/thread_info.h and include/linux/restart_block.h)
 
 - cpus_have_cap() reworked to avoid __builtin_constant_p() for static
   key use (also touching drivers/irqchip/irq-gic-v3.c)
 
 - Uprobes support (currently only for native 64-bit tasks)
 
 - Emulation of kernel Privileged Access Never (PAN) using TTBR0_EL1
   switching to a reserved page table
 
 - CPU capacity information passing via DT or sysfs (used by the
   scheduler)
 
 - Support for systems without FP/SIMD (IOW, kernel avoids touching these
   registers; there is no soft-float ABI, nor kernel emulation for
   AArch64 FP/SIMD)
 
 - Handling of hardware watchpoint with unaligned addresses, varied
   lengths and offsets from base
 
 - Use of the page table contiguous hint for kernel mappings
 
 - Hugetlb fixes for sizes involving the contiguous hint
 
 - Remove unnecessary I-cache invalidation in flush_cache_range()
 
 - CNTHCTL_EL2 access fix for CPUs with VHE support (ARMv8.1)
 
 - Boot-time checks for writable+executable kernel mappings
 
 - Simplify asm/opcodes.h and avoid including the 32-bit ARM counterpart
   and make the arm64 kernel headers self-consistent (Xen headers patch
   merged separately)
 
 - Workaround for broken .inst support in certain binutils versions
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - struct thread_info moved off-stack (also touching
   include/linux/thread_info.h and include/linux/restart_block.h)

 - cpus_have_cap() reworked to avoid __builtin_constant_p() for static
   key use (also touching drivers/irqchip/irq-gic-v3.c)

 - uprobes support (currently only for native 64-bit tasks)

 - Emulation of kernel Privileged Access Never (PAN) using TTBR0_EL1
   switching to a reserved page table

 - CPU capacity information passing via DT or sysfs (used by the
   scheduler)

 - support for systems without FP/SIMD (IOW, kernel avoids touching
   these registers; there is no soft-float ABI, nor kernel emulation for
   AArch64 FP/SIMD)

 - handling of hardware watchpoint with unaligned addresses, varied
   lengths and offsets from base

 - use of the page table contiguous hint for kernel mappings

 - hugetlb fixes for sizes involving the contiguous hint

 - remove unnecessary I-cache invalidation in flush_cache_range()

 - CNTHCTL_EL2 access fix for CPUs with VHE support (ARMv8.1)

 - boot-time checks for writable+executable kernel mappings

 - simplify asm/opcodes.h and avoid including the 32-bit ARM counterpart
   and make the arm64 kernel headers self-consistent (Xen headers patch
   merged separately)

 - Workaround for broken .inst support in certain binutils versions

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (60 commits)
  arm64: Disable PAN on uaccess_enable()
  arm64: Work around broken .inst when defective gas is detected
  arm64: Add detection code for broken .inst support in binutils
  arm64: Remove reference to asm/opcodes.h
  arm64: Get rid of asm/opcodes.h
  arm64: smp: Prevent raw_smp_processor_id() recursion
  arm64: head.S: Fix CNTHCTL_EL2 access on VHE system
  arm64: Remove I-cache invalidation from flush_cache_range()
  arm64: Enable HIBERNATION in defconfig
  arm64: Enable CONFIG_ARM64_SW_TTBR0_PAN
  arm64: xen: Enable user access before a privcmd hvc call
  arm64: Handle faults caused by inadvertent user access with PAN enabled
  arm64: Disable TTBR0_EL1 during normal kernel execution
  arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1
  arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro
  arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
  arm64: Update the synchronous external abort fault description
  selftests: arm64: add test for unaligned/inexact watchpoint handling
  arm64: Allow hw watchpoint of length 3,5,6 and 7
  arm64: hw_breakpoint: Handle inexact watchpoint addresses
  ...
2016-12-13 16:39:21 -08:00

230 lines
6.0 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/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 */
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 */
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 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 sys_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];
bool this_cpu_has_cap(unsigned int cap);
static inline bool cpu_have_feature(unsigned int num)
{
return elf_hwcap & (1UL << num);
}
/* 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]);
}
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_branch_enable(&cpu_hwcap_keys[num]);
}
}
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(const 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(const 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;
}
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;
}
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_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_const_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));
}
static inline bool system_supports_fpsimd(void)
{
return !cpus_have_const_cap(ARM64_HAS_NO_FPSIMD);
}
static inline bool system_uses_ttbr0_pan(void)
{
return IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN) &&
!cpus_have_cap(ARM64_HAS_PAN);
}
#endif /* __ASSEMBLY__ */
#endif