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alistair23-linux/arch/arm64/kernel/cpufeature.c
Will Deacon 5717fe5ab3 arm64: cpufeature: Don't treat granule sizes as strict 
If a CPU doesn't support the page size for which the kernel is
configured, then we will complain and refuse to bring it online. For
secondary CPUs (and the boot CPU on a system booting with EFI), we will
also print an error identifying the mismatch.

Consequently, the only time that the cpufeature code can detect a
granule size mismatch is for a granule other than the one that is
currently being used. Although we would rather such systems didn't
exist, we've unfortunately lost that battle and Kevin reports that
on his amlogic S922X (odroid-n2 board) we end up warning and taining
with defconfig because 16k pages are not supported by all of the CPUs.

In such a situation, we don't actually care about the feature mismatch,
particularly now that KVM only exposes the sanitised view of the CPU
registers (commit 93390c0a1b - "arm64: KVM: Hide unsupported AArch64
CPU features from guests"). Treat the granule fields as non-strict and
let Kevin run without a tainted kernel.

Cc: Marc Zyngier <maz@kernel.org>
Reported-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
[catalin.marinas@arm.com: changelog updated with KVM sanitised regs commit]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-08-13 12:56:35 +01:00

2199 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Contains CPU feature definitions
*
* Copyright (C) 2015 ARM Ltd.
*/
#define pr_fmt(fmt) "CPU features: " fmt
#include <linux/bsearch.h>
#include <linux/cpumask.h>
#include <linux/crash_dump.h>
#include <linux/sort.h>
#include <linux/stop_machine.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
#include <asm/fpsimd.h>
#include <asm/mmu_context.h>
#include <asm/processor.h>
#include <asm/sysreg.h>
#include <asm/traps.h>
#include <asm/virt.h>
/* Kernel representation of AT_HWCAP and AT_HWCAP2 */
static unsigned long elf_hwcap __read_mostly;
#ifdef CONFIG_COMPAT
#define COMPAT_ELF_HWCAP_DEFAULT \
(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
COMPAT_HWCAP_LPAE)
unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
unsigned int compat_elf_hwcap2 __read_mostly;
#endif
DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
EXPORT_SYMBOL(cpu_hwcaps);
static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS];
/* Need also bit for ARM64_CB_PATCH */
DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE);
/*
* Flag to indicate if we have computed the system wide
* capabilities based on the boot time active CPUs. This
* will be used to determine if a new booting CPU should
* go through the verification process to make sure that it
* supports the system capabilities, without using a hotplug
* notifier.
*/
static bool sys_caps_initialised;
static inline void set_sys_caps_initialised(void)
{
sys_caps_initialised = true;
}
static int dump_cpu_hwcaps(struct notifier_block *self, unsigned long v, void *p)
{
/* file-wide pr_fmt adds "CPU features: " prefix */
pr_emerg("0x%*pb\n", ARM64_NCAPS, &cpu_hwcaps);
return 0;
}
static struct notifier_block cpu_hwcaps_notifier = {
.notifier_call = dump_cpu_hwcaps
};
static int __init register_cpu_hwcaps_dumper(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
&cpu_hwcaps_notifier);
return 0;
}
__initcall(register_cpu_hwcaps_dumper);
DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
EXPORT_SYMBOL(cpu_hwcap_keys);
#define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
{ \
.sign = SIGNED, \
.visible = VISIBLE, \
.strict = STRICT, \
.type = TYPE, \
.shift = SHIFT, \
.width = WIDTH, \
.safe_val = SAFE_VAL, \
}
/* Define a feature with unsigned values */
#define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
/* Define a feature with a signed value */
#define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
#define ARM64_FTR_END \
{ \
.width = 0, \
}
/* meta feature for alternatives */
static bool __maybe_unused
cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
/*
* NOTE: Any changes to the visibility of features should be kept in
* sync with the documentation of the CPU feature register ABI.
*/
static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_TS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_FHM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_DP_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM4_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SM3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64isar1[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_SB_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPI_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_GPA_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_LRCPC_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_FCMA_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_JSCVT_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_API_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_APA_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR1_DPB_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_CSV2_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_DIT_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SVE),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_SVE_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_RAS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_GIC_SHIFT, 4, 0),
S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
/* Linux doesn't care about the EL3 */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL2_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SM4_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SHA3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_BITPERM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_AES_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ZFR0_SVEVER_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
/*
* We already refuse to boot CPUs that don't support our configured
* page size, so we can only detect mismatches for a page size other
* than the one we're currently using. Unfortunately, SoCs like this
* exist in the wild so, even though we don't like it, we'll have to go
* along with it and treat them as non-strict.
*/
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
/* Linux shouldn't care about secure memory */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
/*
* Differing PARange is fine as long as all peripherals and memory are mapped
* within the minimum PARange of all CPUs
*/
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_FWB_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_AT_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_ctr[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DIC_SHIFT, 1, 1),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IDC_SHIFT, 1, 1),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_CWG_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_OR_ZERO_SAFE, CTR_ERG_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
/*
* Linux can handle differing I-cache policies. Userspace JITs will
* make use of *minLine.
* If we have differing I-cache policies, report it as the weakest - VIPT.
*/
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT), /* L1Ip */
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
ARM64_FTR_END,
};
struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
.name = "SYS_CTR_EL0",
.ftr_bits = ftr_ctr
};
static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0xf), /* InnerShr */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0), /* FCSE */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0), /* AuxReg */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0), /* TCM */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0), /* ShareLvl */
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0xf), /* OuterShr */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* PMSA */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* VMSA */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 36, 28, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64DFR0_PMSVER_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
/*
* We can instantiate multiple PMU instances with different levels
* of support.
*/
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_mvfr2[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* FPMisc */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* SIMDMisc */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_dczid[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 4, 1, 1), /* DZP */
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* BS */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_isar5[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_RDM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_CRC32_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA2_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SHA1_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_AES_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_ISAR5_SEVL_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* ac2 */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_pfr0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0), /* State3 */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0), /* State2 */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0), /* State1 */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* State0 */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_dfr0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf), /* PerfMon */
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_zcr[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
ZCR_ELx_LEN_SHIFT, ZCR_ELx_LEN_SIZE, 0), /* LEN */
ARM64_FTR_END,
};
/*
* Common ftr bits for a 32bit register with all hidden, strict
* attributes, with 4bit feature fields and a default safe value of
* 0. Covers the following 32bit registers:
* id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
*/
static const struct arm64_ftr_bits ftr_generic_32bits[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
ARM64_FTR_END,
};
/* Table for a single 32bit feature value */
static const struct arm64_ftr_bits ftr_single32[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_raz[] = {
ARM64_FTR_END,
};
#define ARM64_FTR_REG(id, table) { \
.sys_id = id, \
.reg = &(struct arm64_ftr_reg){ \
.name = #id, \
.ftr_bits = &((table)[0]), \
}}
static const struct __ftr_reg_entry {
u32 sys_id;
struct arm64_ftr_reg *reg;
} arm64_ftr_regs[] = {
/* Op1 = 0, CRn = 0, CRm = 1 */
ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_id_dfr0),
ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
/* Op1 = 0, CRn = 0, CRm = 2 */
ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
/* Op1 = 0, CRn = 0, CRm = 3 */
ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
/* Op1 = 0, CRn = 0, CRm = 4 */
ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1),
ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
/* Op1 = 0, CRn = 0, CRm = 5 */
ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
/* Op1 = 0, CRn = 0, CRm = 6 */
ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_id_aa64isar1),
/* Op1 = 0, CRn = 0, CRm = 7 */
ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
ARM64_FTR_REG(SYS_ID_AA64MMFR2_EL1, ftr_id_aa64mmfr2),
/* Op1 = 0, CRn = 1, CRm = 2 */
ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
/* Op1 = 3, CRn = 0, CRm = 0 */
{ SYS_CTR_EL0, &arm64_ftr_reg_ctrel0 },
ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
/* Op1 = 3, CRn = 14, CRm = 0 */
ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
};
static int search_cmp_ftr_reg(const void *id, const void *regp)
{
return (int)(unsigned long)id - (int)((const struct __ftr_reg_entry *)regp)->sys_id;
}
/*
* get_arm64_ftr_reg - Lookup a feature register entry using its
* sys_reg() encoding. With the array arm64_ftr_regs sorted in the
* ascending order of sys_id , we use binary search to find a matching
* entry.
*
* returns - Upon success, matching ftr_reg entry for id.
* - NULL on failure. It is upto the caller to decide
* the impact of a failure.
*/
static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
{
const struct __ftr_reg_entry *ret;
ret = bsearch((const void *)(unsigned long)sys_id,
arm64_ftr_regs,
ARRAY_SIZE(arm64_ftr_regs),
sizeof(arm64_ftr_regs[0]),
search_cmp_ftr_reg);
if (ret)
return ret->reg;
return NULL;
}
static u64 arm64_ftr_set_value(const struct arm64_ftr_bits *ftrp, s64 reg,
s64 ftr_val)
{
u64 mask = arm64_ftr_mask(ftrp);
reg &= ~mask;
reg |= (ftr_val << ftrp->shift) & mask;
return reg;
}
static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
s64 cur)
{
s64 ret = 0;
switch (ftrp->type) {
case FTR_EXACT:
ret = ftrp->safe_val;
break;
case FTR_LOWER_SAFE:
ret = new < cur ? new : cur;
break;
case FTR_HIGHER_OR_ZERO_SAFE:
if (!cur || !new)
break;
/* Fallthrough */
case FTR_HIGHER_SAFE:
ret = new > cur ? new : cur;
break;
default:
BUG();
}
return ret;
}
static void __init sort_ftr_regs(void)
{
int i;
/* Check that the array is sorted so that we can do the binary search */
for (i = 1; i < ARRAY_SIZE(arm64_ftr_regs); i++)
BUG_ON(arm64_ftr_regs[i].sys_id < arm64_ftr_regs[i - 1].sys_id);
}
/*
* Initialise the CPU feature register from Boot CPU values.
* Also initiliases the strict_mask for the register.
* Any bits that are not covered by an arm64_ftr_bits entry are considered
* RES0 for the system-wide value, and must strictly match.
*/
static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
{
u64 val = 0;
u64 strict_mask = ~0x0ULL;
u64 user_mask = 0;
u64 valid_mask = 0;
const struct arm64_ftr_bits *ftrp;
struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
BUG_ON(!reg);
for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
u64 ftr_mask = arm64_ftr_mask(ftrp);
s64 ftr_new = arm64_ftr_value(ftrp, new);
val = arm64_ftr_set_value(ftrp, val, ftr_new);
valid_mask |= ftr_mask;
if (!ftrp->strict)
strict_mask &= ~ftr_mask;
if (ftrp->visible)
user_mask |= ftr_mask;
else
reg->user_val = arm64_ftr_set_value(ftrp,
reg->user_val,
ftrp->safe_val);
}
val &= valid_mask;
reg->sys_val = val;
reg->strict_mask = strict_mask;
reg->user_mask = user_mask;
}
extern const struct arm64_cpu_capabilities arm64_errata[];
static const struct arm64_cpu_capabilities arm64_features[];
static void __init
init_cpu_hwcaps_indirect_list_from_array(const struct arm64_cpu_capabilities *caps)
{
for (; caps->matches; caps++) {
if (WARN(caps->capability >= ARM64_NCAPS,
"Invalid capability %d\n", caps->capability))
continue;
if (WARN(cpu_hwcaps_ptrs[caps->capability],
"Duplicate entry for capability %d\n",
caps->capability))
continue;
cpu_hwcaps_ptrs[caps->capability] = caps;
}
}
static void __init init_cpu_hwcaps_indirect_list(void)
{
init_cpu_hwcaps_indirect_list_from_array(arm64_features);
init_cpu_hwcaps_indirect_list_from_array(arm64_errata);
}
static void __init setup_boot_cpu_capabilities(void);
void __init init_cpu_features(struct cpuinfo_arm64 *info)
{
/* Before we start using the tables, make sure it is sorted */
sort_ftr_regs();
init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
init_cpu_ftr_reg(SYS_ID_AA64MMFR2_EL1, info->reg_id_aa64mmfr2);
init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
}
if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr);
sve_init_vq_map();
}
/*
* Initialize the indirect array of CPU hwcaps capabilities pointers
* before we handle the boot CPU below.
*/
init_cpu_hwcaps_indirect_list();
/*
* Detect and enable early CPU capabilities based on the boot CPU,
* after we have initialised the CPU feature infrastructure.
*/
setup_boot_cpu_capabilities();
}
static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
{
const struct arm64_ftr_bits *ftrp;
for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
s64 ftr_new = arm64_ftr_value(ftrp, new);
if (ftr_cur == ftr_new)
continue;
/* Find a safe value */
ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
}
}
static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
{
struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
BUG_ON(!regp);
update_cpu_ftr_reg(regp, val);
if ((boot & regp->strict_mask) == (val & regp->strict_mask))
return 0;
pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
regp->name, boot, cpu, val);
return 1;
}
/*
* Update system wide CPU feature registers with the values from a
* non-boot CPU. Also performs SANITY checks to make sure that there
* aren't any insane variations from that of the boot CPU.
*/
void update_cpu_features(int cpu,
struct cpuinfo_arm64 *info,
struct cpuinfo_arm64 *boot)
{
int taint = 0;
/*
* The kernel can handle differing I-cache policies, but otherwise
* caches should look identical. Userspace JITs will make use of
* *minLine.
*/
taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
info->reg_ctr, boot->reg_ctr);
/*
* Userspace may perform DC ZVA instructions. Mismatched block sizes
* could result in too much or too little memory being zeroed if a
* process is preempted and migrated between CPUs.
*/
taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
info->reg_dczid, boot->reg_dczid);
/* If different, timekeeping will be broken (especially with KVM) */
taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
info->reg_cntfrq, boot->reg_cntfrq);
/*
* The kernel uses self-hosted debug features and expects CPUs to
* support identical debug features. We presently need CTX_CMPs, WRPs,
* and BRPs to be identical.
* ID_AA64DFR1 is currently RES0.
*/
taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
/*
* Even in big.LITTLE, processors should be identical instruction-set
* wise.
*/
taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
/*
* Differing PARange support is fine as long as all peripherals and
* memory are mapped within the minimum PARange of all CPUs.
* Linux should not care about secure memory.
*/
taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
taint |= check_update_ftr_reg(SYS_ID_AA64MMFR2_EL1, cpu,
info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
/*
* EL3 is not our concern.
*/
taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
/*
* If we have AArch32, we care about 32-bit features for compat.
* If the system doesn't support AArch32, don't update them.
*/
if (id_aa64pfr0_32bit_el0(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
info->reg_id_dfr0, boot->reg_id_dfr0);
taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
info->reg_id_isar0, boot->reg_id_isar0);
taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
info->reg_id_isar1, boot->reg_id_isar1);
taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
info->reg_id_isar2, boot->reg_id_isar2);
taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
info->reg_id_isar3, boot->reg_id_isar3);
taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
info->reg_id_isar4, boot->reg_id_isar4);
taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
info->reg_id_isar5, boot->reg_id_isar5);
/*
* Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
* ACTLR formats could differ across CPUs and therefore would have to
* be trapped for virtualization anyway.
*/
taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
info->reg_id_mmfr0, boot->reg_id_mmfr0);
taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
info->reg_id_mmfr1, boot->reg_id_mmfr1);
taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
info->reg_id_mmfr2, boot->reg_id_mmfr2);
taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
info->reg_id_mmfr3, boot->reg_id_mmfr3);
taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
info->reg_id_pfr0, boot->reg_id_pfr0);
taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
info->reg_id_pfr1, boot->reg_id_pfr1);
taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
info->reg_mvfr0, boot->reg_mvfr0);
taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
info->reg_mvfr1, boot->reg_mvfr1);
taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
info->reg_mvfr2, boot->reg_mvfr2);
}
if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
info->reg_zcr, boot->reg_zcr);
/* Probe vector lengths, unless we already gave up on SVE */
if (id_aa64pfr0_sve(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) &&
!sys_caps_initialised)
sve_update_vq_map();
}
/*
* Mismatched CPU features are a recipe for disaster. Don't even
* pretend to support them.
*/
if (taint) {
pr_warn_once("Unsupported CPU feature variation detected.\n");
add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
}
}
u64 read_sanitised_ftr_reg(u32 id)
{
struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
/* We shouldn't get a request for an unsupported register */
BUG_ON(!regp);
return regp->sys_val;
}
#define read_sysreg_case(r) \
case r: return read_sysreg_s(r)
/*
* __read_sysreg_by_encoding() - Used by a STARTING cpu before cpuinfo is populated.
* Read the system register on the current CPU
*/
static u64 __read_sysreg_by_encoding(u32 sys_id)
{
switch (sys_id) {
read_sysreg_case(SYS_ID_PFR0_EL1);
read_sysreg_case(SYS_ID_PFR1_EL1);
read_sysreg_case(SYS_ID_DFR0_EL1);
read_sysreg_case(SYS_ID_MMFR0_EL1);
read_sysreg_case(SYS_ID_MMFR1_EL1);
read_sysreg_case(SYS_ID_MMFR2_EL1);
read_sysreg_case(SYS_ID_MMFR3_EL1);
read_sysreg_case(SYS_ID_ISAR0_EL1);
read_sysreg_case(SYS_ID_ISAR1_EL1);
read_sysreg_case(SYS_ID_ISAR2_EL1);
read_sysreg_case(SYS_ID_ISAR3_EL1);
read_sysreg_case(SYS_ID_ISAR4_EL1);
read_sysreg_case(SYS_ID_ISAR5_EL1);
read_sysreg_case(SYS_MVFR0_EL1);
read_sysreg_case(SYS_MVFR1_EL1);
read_sysreg_case(SYS_MVFR2_EL1);
read_sysreg_case(SYS_ID_AA64PFR0_EL1);
read_sysreg_case(SYS_ID_AA64PFR1_EL1);
read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
read_sysreg_case(SYS_ID_AA64DFR0_EL1);
read_sysreg_case(SYS_ID_AA64DFR1_EL1);
read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
read_sysreg_case(SYS_ID_AA64MMFR1_EL1);
read_sysreg_case(SYS_ID_AA64MMFR2_EL1);
read_sysreg_case(SYS_ID_AA64ISAR0_EL1);
read_sysreg_case(SYS_ID_AA64ISAR1_EL1);
read_sysreg_case(SYS_CNTFRQ_EL0);
read_sysreg_case(SYS_CTR_EL0);
read_sysreg_case(SYS_DCZID_EL0);
default:
BUG();
return 0;
}
}
#include <linux/irqchip/arm-gic-v3.h>
static bool
feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
{
int val = cpuid_feature_extract_field(reg, entry->field_pos, entry->sign);
return val >= entry->min_field_value;
}
static bool
has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
{
u64 val;
WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
if (scope == SCOPE_SYSTEM)
val = read_sanitised_ftr_reg(entry->sys_reg);
else
val = __read_sysreg_by_encoding(entry->sys_reg);
return feature_matches(val, entry);
}
static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
{
bool has_sre;
if (!has_cpuid_feature(entry, scope))
return false;
has_sre = gic_enable_sre();
if (!has_sre)
pr_warn_once("%s present but disabled by higher exception level\n",
entry->desc);
return has_sre;
}
static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
{
u32 midr = read_cpuid_id();
/* Cavium ThunderX pass 1.x and 2.x */
return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX,
MIDR_CPU_VAR_REV(0, 0),
MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
}
static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)
{
u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
return cpuid_feature_extract_signed_field(pfr0,
ID_AA64PFR0_FP_SHIFT) < 0;
}
static bool has_cache_idc(const struct arm64_cpu_capabilities *entry,
int scope)
{
u64 ctr;
if (scope == SCOPE_SYSTEM)
ctr = arm64_ftr_reg_ctrel0.sys_val;
else
ctr = read_cpuid_effective_cachetype();
return ctr & BIT(CTR_IDC_SHIFT);
}
static void cpu_emulate_effective_ctr(const struct arm64_cpu_capabilities *__unused)
{
/*
* If the CPU exposes raw CTR_EL0.IDC = 0, while effectively
* CTR_EL0.IDC = 1 (from CLIDR values), we need to trap accesses
* to the CTR_EL0 on this CPU and emulate it with the real/safe
* value.
*/
if (!(read_cpuid_cachetype() & BIT(CTR_IDC_SHIFT)))
sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
}
static bool has_cache_dic(const struct arm64_cpu_capabilities *entry,
int scope)
{
u64 ctr;
if (scope == SCOPE_SYSTEM)
ctr = arm64_ftr_reg_ctrel0.sys_val;
else
ctr = read_cpuid_cachetype();
return ctr & BIT(CTR_DIC_SHIFT);
}
static bool __maybe_unused
has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
{
/*
* Kdump isn't guaranteed to power-off all secondary CPUs, CNP
* may share TLB entries with a CPU stuck in the crashed
* kernel.
*/
if (is_kdump_kernel())
return false;
return has_cpuid_feature(entry, scope);
}
static bool __meltdown_safe = true;
static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
int scope)
{
/* List of CPUs that are not vulnerable and don't need KPTI */
static const struct midr_range kpti_safe_list[] = {
MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A53),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A55),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
MIDR_ALL_VERSIONS(MIDR_HISI_TSV110),
{ /* sentinel */ }
};
char const *str = "kpti command line option";
bool meltdown_safe;
meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
/* Defer to CPU feature registers */
if (has_cpuid_feature(entry, scope))
meltdown_safe = true;
if (!meltdown_safe)
__meltdown_safe = false;
/*
* For reasons that aren't entirely clear, enabling KPTI on Cavium
* ThunderX leads to apparent I-cache corruption of kernel text, which
* ends as well as you might imagine. Don't even try.
*/
if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
str = "ARM64_WORKAROUND_CAVIUM_27456";
__kpti_forced = -1;
}
/* Useful for KASLR robustness */
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) {
if (!__kpti_forced) {
str = "KASLR";
__kpti_forced = 1;
}
}
if (cpu_mitigations_off() && !__kpti_forced) {
str = "mitigations=off";
__kpti_forced = -1;
}
if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
pr_info_once("kernel page table isolation disabled by kernel configuration\n");
return false;
}
/* Forced? */
if (__kpti_forced) {
pr_info_once("kernel page table isolation forced %s by %s\n",
__kpti_forced > 0 ? "ON" : "OFF", str);
return __kpti_forced > 0;
}
return !meltdown_safe;
}
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
static void
kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
{
typedef void (kpti_remap_fn)(int, int, phys_addr_t);
extern kpti_remap_fn idmap_kpti_install_ng_mappings;
kpti_remap_fn *remap_fn;
static bool kpti_applied = false;
int cpu = smp_processor_id();
/*
* We don't need to rewrite the page-tables if either we've done
* it already or we have KASLR enabled and therefore have not
* created any global mappings at all.
*/
if (kpti_applied || kaslr_offset() > 0)
return;
remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
cpu_install_idmap();
remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
cpu_uninstall_idmap();
if (!cpu)
kpti_applied = true;
return;
}
#else
static void
kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
{
}
#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
static int __init parse_kpti(char *str)
{
bool enabled;
int ret = strtobool(str, &enabled);
if (ret)
return ret;
__kpti_forced = enabled ? 1 : -1;
return 0;
}
early_param("kpti", parse_kpti);
#ifdef CONFIG_ARM64_HW_AFDBM
static inline void __cpu_enable_hw_dbm(void)
{
u64 tcr = read_sysreg(tcr_el1) | TCR_HD;
write_sysreg(tcr, tcr_el1);
isb();
}
static bool cpu_has_broken_dbm(void)
{
/* List of CPUs which have broken DBM support. */
static const struct midr_range cpus[] = {
#ifdef CONFIG_ARM64_ERRATUM_1024718
MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0), // A55 r0p0 -r1p0
#endif
{},
};
return is_midr_in_range_list(read_cpuid_id(), cpus);
}
static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
{
return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
!cpu_has_broken_dbm();
}
static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
{
if (cpu_can_use_dbm(cap))
__cpu_enable_hw_dbm();
}
static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
int __unused)
{
static bool detected = false;
/*
* DBM is a non-conflicting feature. i.e, the kernel can safely
* run a mix of CPUs with and without the feature. So, we
* unconditionally enable the capability to allow any late CPU
* to use the feature. We only enable the control bits on the
* CPU, if it actually supports.
*
* We have to make sure we print the "feature" detection only
* when at least one CPU actually uses it. So check if this CPU
* can actually use it and print the message exactly once.
*
* This is safe as all CPUs (including secondary CPUs - due to the
* LOCAL_CPU scope - and the hotplugged CPUs - via verification)
* goes through the "matches" check exactly once. Also if a CPU
* matches the criteria, it is guaranteed that the CPU will turn
* the DBM on, as the capability is unconditionally enabled.
*/
if (!detected && cpu_can_use_dbm(cap)) {
detected = true;
pr_info("detected: Hardware dirty bit management\n");
}
return true;
}
#endif
#ifdef CONFIG_ARM64_VHE
static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
{
return is_kernel_in_hyp_mode();
}
static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
{
/*
* Copy register values that aren't redirected by hardware.
*
* Before code patching, we only set tpidr_el1, all CPUs need to copy
* this value to tpidr_el2 before we patch the code. Once we've done
* that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
* do anything here.
*/
if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
}
#endif
static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
{
u64 val = read_sysreg_s(SYS_CLIDR_EL1);
/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
WARN_ON(val & (7 << 27 | 7 << 21));
}
#ifdef CONFIG_ARM64_SSBD
static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
{
if (user_mode(regs))
return 1;
if (instr & BIT(PSTATE_Imm_shift))
regs->pstate |= PSR_SSBS_BIT;
else
regs->pstate &= ~PSR_SSBS_BIT;
arm64_skip_faulting_instruction(regs, 4);
return 0;
}
static struct undef_hook ssbs_emulation_hook = {
.instr_mask = ~(1U << PSTATE_Imm_shift),
.instr_val = 0xd500401f | PSTATE_SSBS,
.fn = ssbs_emulation_handler,
};
static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
{
static bool undef_hook_registered = false;
static DEFINE_RAW_SPINLOCK(hook_lock);
raw_spin_lock(&hook_lock);
if (!undef_hook_registered) {
register_undef_hook(&ssbs_emulation_hook);
undef_hook_registered = true;
}
raw_spin_unlock(&hook_lock);
if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
arm64_set_ssbd_mitigation(false);
} else {
arm64_set_ssbd_mitigation(true);
}
}
#endif /* CONFIG_ARM64_SSBD */
#ifdef CONFIG_ARM64_PAN
static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
{
/*
* We modify PSTATE. This won't work from irq context as the PSTATE
* is discarded once we return from the exception.
*/
WARN_ON_ONCE(in_interrupt());
sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
asm(SET_PSTATE_PAN(1));
}
#endif /* CONFIG_ARM64_PAN */
#ifdef CONFIG_ARM64_RAS_EXTN
static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
{
/* Firmware may have left a deferred SError in this register. */
write_sysreg_s(0, SYS_DISR_EL1);
}
#endif /* CONFIG_ARM64_RAS_EXTN */
#ifdef CONFIG_ARM64_PTR_AUTH
static void cpu_enable_address_auth(struct arm64_cpu_capabilities const *cap)
{
sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ENIA | SCTLR_ELx_ENIB |
SCTLR_ELx_ENDA | SCTLR_ELx_ENDB);
}
#endif /* CONFIG_ARM64_PTR_AUTH */
#ifdef CONFIG_ARM64_PSEUDO_NMI
static bool enable_pseudo_nmi;
static int __init early_enable_pseudo_nmi(char *p)
{
return strtobool(p, &enable_pseudo_nmi);
}
early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);
static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
int scope)
{
return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
}
#endif
static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "GIC system register CPU interface",
.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
.matches = has_useable_gicv3_cpuif,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.field_pos = ID_AA64PFR0_GIC_SHIFT,
.sign = FTR_UNSIGNED,
.min_field_value = 1,
},
#ifdef CONFIG_ARM64_PAN
{
.desc = "Privileged Access Never",
.capability = ARM64_HAS_PAN,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64MMFR1_EL1,
.field_pos = ID_AA64MMFR1_PAN_SHIFT,
.sign = FTR_UNSIGNED,
.min_field_value = 1,
.cpu_enable = cpu_enable_pan,
},
#endif /* CONFIG_ARM64_PAN */
#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
{
.desc = "LSE atomic instructions",
.capability = ARM64_HAS_LSE_ATOMICS,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64ISAR0_EL1,
.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
.sign = FTR_UNSIGNED,
.min_field_value = 2,
},
#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
{
.desc = "Software prefetching using PRFM",
.capability = ARM64_HAS_NO_HW_PREFETCH,
.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
.matches = has_no_hw_prefetch,
},
#ifdef CONFIG_ARM64_UAO
{
.desc = "User Access Override",
.capability = ARM64_HAS_UAO,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64MMFR2_EL1,
.field_pos = ID_AA64MMFR2_UAO_SHIFT,
.min_field_value = 1,
/*
* We rely on stop_machine() calling uao_thread_switch() to set
* UAO immediately after patching.
*/
},
#endif /* CONFIG_ARM64_UAO */
#ifdef CONFIG_ARM64_PAN
{
.capability = ARM64_ALT_PAN_NOT_UAO,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = cpufeature_pan_not_uao,
},
#endif /* CONFIG_ARM64_PAN */
#ifdef CONFIG_ARM64_VHE
{
.desc = "Virtualization Host Extensions",
.capability = ARM64_HAS_VIRT_HOST_EXTN,
.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
.matches = runs_at_el2,
.cpu_enable = cpu_copy_el2regs,
},
#endif /* CONFIG_ARM64_VHE */
{
.desc = "32-bit EL0 Support",
.capability = ARM64_HAS_32BIT_EL0,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64PFR0_EL0_SHIFT,
.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
},
{
.desc = "Kernel page table isolation (KPTI)",
.capability = ARM64_UNMAP_KERNEL_AT_EL0,
.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
/*
* The ID feature fields below are used to indicate that
* the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
* more details.
*/
.sys_reg = SYS_ID_AA64PFR0_EL1,
.field_pos = ID_AA64PFR0_CSV3_SHIFT,
.min_field_value = 1,
.matches = unmap_kernel_at_el0,
.cpu_enable = kpti_install_ng_mappings,
},
{
/* FP/SIMD is not implemented */
.capability = ARM64_HAS_NO_FPSIMD,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.min_field_value = 0,
.matches = has_no_fpsimd,
},
#ifdef CONFIG_ARM64_PMEM
{
.desc = "Data cache clean to Point of Persistence",
.capability = ARM64_HAS_DCPOP,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.field_pos = ID_AA64ISAR1_DPB_SHIFT,
.min_field_value = 1,
},
{
.desc = "Data cache clean to Point of Deep Persistence",
.capability = ARM64_HAS_DCPODP,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64ISAR1_DPB_SHIFT,
.min_field_value = 2,
},
#endif
#ifdef CONFIG_ARM64_SVE
{
.desc = "Scalable Vector Extension",
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.capability = ARM64_SVE,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64PFR0_SVE_SHIFT,
.min_field_value = ID_AA64PFR0_SVE,
.matches = has_cpuid_feature,
.cpu_enable = sve_kernel_enable,
},
#endif /* CONFIG_ARM64_SVE */
#ifdef CONFIG_ARM64_RAS_EXTN
{
.desc = "RAS Extension Support",
.capability = ARM64_HAS_RAS_EXTN,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64PFR0_RAS_SHIFT,
.min_field_value = ID_AA64PFR0_RAS_V1,
.cpu_enable = cpu_clear_disr,
},
#endif /* CONFIG_ARM64_RAS_EXTN */
{
.desc = "Data cache clean to the PoU not required for I/D coherence",
.capability = ARM64_HAS_CACHE_IDC,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cache_idc,
.cpu_enable = cpu_emulate_effective_ctr,
},
{
.desc = "Instruction cache invalidation not required for I/D coherence",
.capability = ARM64_HAS_CACHE_DIC,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cache_dic,
},
{
.desc = "Stage-2 Force Write-Back",
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.capability = ARM64_HAS_STAGE2_FWB,
.sys_reg = SYS_ID_AA64MMFR2_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64MMFR2_FWB_SHIFT,
.min_field_value = 1,
.matches = has_cpuid_feature,
.cpu_enable = cpu_has_fwb,
},
#ifdef CONFIG_ARM64_HW_AFDBM
{
/*
* Since we turn this on always, we don't want the user to
* think that the feature is available when it may not be.
* So hide the description.
*
* .desc = "Hardware pagetable Dirty Bit Management",
*
*/
.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
.capability = ARM64_HW_DBM,
.sys_reg = SYS_ID_AA64MMFR1_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
.min_field_value = 2,
.matches = has_hw_dbm,
.cpu_enable = cpu_enable_hw_dbm,
},
#endif
{
.desc = "CRC32 instructions",
.capability = ARM64_HAS_CRC32,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64ISAR0_EL1,
.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
.min_field_value = 1,
},
#ifdef CONFIG_ARM64_SSBD
{
.desc = "Speculative Store Bypassing Safe (SSBS)",
.capability = ARM64_SSBS,
.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64PFR1_EL1,
.field_pos = ID_AA64PFR1_SSBS_SHIFT,
.sign = FTR_UNSIGNED,
.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
.cpu_enable = cpu_enable_ssbs,
},
#endif
#ifdef CONFIG_ARM64_CNP
{
.desc = "Common not Private translations",
.capability = ARM64_HAS_CNP,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_useable_cnp,
.sys_reg = SYS_ID_AA64MMFR2_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64MMFR2_CNP_SHIFT,
.min_field_value = 1,
.cpu_enable = cpu_enable_cnp,
},
#endif
{
.desc = "Speculation barrier (SB)",
.capability = ARM64_HAS_SB,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.field_pos = ID_AA64ISAR1_SB_SHIFT,
.sign = FTR_UNSIGNED,
.min_field_value = 1,
},
#ifdef CONFIG_ARM64_PTR_AUTH
{
.desc = "Address authentication (architected algorithm)",
.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64ISAR1_APA_SHIFT,
.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
.matches = has_cpuid_feature,
.cpu_enable = cpu_enable_address_auth,
},
{
.desc = "Address authentication (IMP DEF algorithm)",
.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64ISAR1_API_SHIFT,
.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
.matches = has_cpuid_feature,
.cpu_enable = cpu_enable_address_auth,
},
{
.desc = "Generic authentication (architected algorithm)",
.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64ISAR1_GPA_SHIFT,
.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
.matches = has_cpuid_feature,
},
{
.desc = "Generic authentication (IMP DEF algorithm)",
.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
.sys_reg = SYS_ID_AA64ISAR1_EL1,
.sign = FTR_UNSIGNED,
.field_pos = ID_AA64ISAR1_GPI_SHIFT,
.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
.matches = has_cpuid_feature,
},
#endif /* CONFIG_ARM64_PTR_AUTH */
#ifdef CONFIG_ARM64_PSEUDO_NMI
{
/*
* Depends on having GICv3
*/
.desc = "IRQ priority masking",
.capability = ARM64_HAS_IRQ_PRIO_MASKING,
.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
.matches = can_use_gic_priorities,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.field_pos = ID_AA64PFR0_GIC_SHIFT,
.sign = FTR_UNSIGNED,
.min_field_value = 1,
},
#endif
{},
};
#define HWCAP_CPUID_MATCH(reg, field, s, min_value) \
.matches = has_cpuid_feature, \
.sys_reg = reg, \
.field_pos = field, \
.sign = s, \
.min_field_value = min_value,
#define __HWCAP_CAP(name, cap_type, cap) \
.desc = name, \
.type = ARM64_CPUCAP_SYSTEM_FEATURE, \
.hwcap_type = cap_type, \
.hwcap = cap, \
#define HWCAP_CAP(reg, field, s, min_value, cap_type, cap) \
{ \
__HWCAP_CAP(#cap, cap_type, cap) \
HWCAP_CPUID_MATCH(reg, field, s, min_value) \
}
#define HWCAP_MULTI_CAP(list, cap_type, cap) \
{ \
__HWCAP_CAP(#cap, cap_type, cap) \
.matches = cpucap_multi_entry_cap_matches, \
.match_list = list, \
}
#ifdef CONFIG_ARM64_PTR_AUTH
static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
{
HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
},
{
HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
},
{},
};
static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
{
HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
},
{
HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
},
{},
};
#endif
static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
#ifdef CONFIG_ARM64_SVE
HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
#endif
HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
#ifdef CONFIG_ARM64_PTR_AUTH
HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
#endif
{},
};
static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
#ifdef CONFIG_COMPAT
HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
#endif
{},
};
static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
{
switch (cap->hwcap_type) {
case CAP_HWCAP:
cpu_set_feature(cap->hwcap);
break;
#ifdef CONFIG_COMPAT
case CAP_COMPAT_HWCAP:
compat_elf_hwcap |= (u32)cap->hwcap;
break;
case CAP_COMPAT_HWCAP2:
compat_elf_hwcap2 |= (u32)cap->hwcap;
break;
#endif
default:
WARN_ON(1);
break;
}
}
/* Check if we have a particular HWCAP enabled */
static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
{
bool rc;
switch (cap->hwcap_type) {
case CAP_HWCAP:
rc = cpu_have_feature(cap->hwcap);
break;
#ifdef CONFIG_COMPAT
case CAP_COMPAT_HWCAP:
rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
break;
case CAP_COMPAT_HWCAP2:
rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
break;
#endif
default:
WARN_ON(1);
rc = false;
}
return rc;
}
static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
{
/* We support emulation of accesses to CPU ID feature registers */
cpu_set_named_feature(CPUID);
for (; hwcaps->matches; hwcaps++)
if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
cap_set_elf_hwcap(hwcaps);
}
static void update_cpu_capabilities(u16 scope_mask)
{
int i;
const struct arm64_cpu_capabilities *caps;
scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
for (i = 0; i < ARM64_NCAPS; i++) {
caps = cpu_hwcaps_ptrs[i];
if (!caps || !(caps->type & scope_mask) ||
cpus_have_cap(caps->capability) ||
!caps->matches(caps, cpucap_default_scope(caps)))
continue;
if (caps->desc)
pr_info("detected: %s\n", caps->desc);
cpus_set_cap(caps->capability);
if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
set_bit(caps->capability, boot_capabilities);
}
}
/*
* Enable all the available capabilities on this CPU. The capabilities
* with BOOT_CPU scope are handled separately and hence skipped here.
*/
static int cpu_enable_non_boot_scope_capabilities(void *__unused)
{
int i;
u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;
for_each_available_cap(i) {
const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];
if (WARN_ON(!cap))
continue;
if (!(cap->type & non_boot_scope))
continue;
if (cap->cpu_enable)
cap->cpu_enable(cap);
}
return 0;
}
/*
* Run through the enabled capabilities and enable() it on all active
* CPUs
*/
static void __init enable_cpu_capabilities(u16 scope_mask)
{
int i;
const struct arm64_cpu_capabilities *caps;
bool boot_scope;
scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);
for (i = 0; i < ARM64_NCAPS; i++) {
unsigned int num;
caps = cpu_hwcaps_ptrs[i];
if (!caps || !(caps->type & scope_mask))
continue;
num = caps->capability;
if (!cpus_have_cap(num))
continue;
/* Ensure cpus_have_const_cap(num) works */
static_branch_enable(&cpu_hwcap_keys[num]);
if (boot_scope && caps->cpu_enable)
/*
* Capabilities with SCOPE_BOOT_CPU scope are finalised
* before any secondary CPU boots. Thus, each secondary
* will enable the capability as appropriate via
* check_local_cpu_capabilities(). The only exception is
* the boot CPU, for which the capability must be
* enabled here. This approach avoids costly
* stop_machine() calls for this case.
*/
caps->cpu_enable(caps);
}
/*
* For all non-boot scope capabilities, use stop_machine()
* as it schedules the work allowing us to modify PSTATE,
* instead of on_each_cpu() which uses an IPI, giving us a
* PSTATE that disappears when we return.
*/
if (!boot_scope)
stop_machine(cpu_enable_non_boot_scope_capabilities,
NULL, cpu_online_mask);
}
/*
* Run through the list of capabilities to check for conflicts.
* If the system has already detected a capability, take necessary
* action on this CPU.
*
* Returns "false" on conflicts.
*/
static bool verify_local_cpu_caps(u16 scope_mask)
{
int i;
bool cpu_has_cap, system_has_cap;
const struct arm64_cpu_capabilities *caps;
scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
for (i = 0; i < ARM64_NCAPS; i++) {
caps = cpu_hwcaps_ptrs[i];
if (!caps || !(caps->type & scope_mask))
continue;
cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
system_has_cap = cpus_have_cap(caps->capability);
if (system_has_cap) {
/*
* Check if the new CPU misses an advertised feature,
* which is not safe to miss.
*/
if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
break;
/*
* We have to issue cpu_enable() irrespective of
* whether the CPU has it or not, as it is enabeld
* system wide. It is upto the call back to take
* appropriate action on this CPU.
*/
if (caps->cpu_enable)
caps->cpu_enable(caps);
} else {
/*
* Check if the CPU has this capability if it isn't
* safe to have when the system doesn't.
*/
if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
break;
}
}
if (i < ARM64_NCAPS) {
pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
smp_processor_id(), caps->capability,
caps->desc, system_has_cap, cpu_has_cap);
return false;
}
return true;
}
/*
* Check for CPU features that are used in early boot
* based on the Boot CPU value.
*/
static void check_early_cpu_features(void)
{
verify_cpu_asid_bits();
/*
* Early features are used by the kernel already. If there
* is a conflict, we cannot proceed further.
*/
if (!verify_local_cpu_caps(SCOPE_BOOT_CPU))
cpu_panic_kernel();
}
static void
verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
{
for (; caps->matches; caps++)
if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
pr_crit("CPU%d: missing HWCAP: %s\n",
smp_processor_id(), caps->desc);
cpu_die_early();
}
}
static void verify_sve_features(void)
{
u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
u64 zcr = read_zcr_features();
unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
unsigned int len = zcr & ZCR_ELx_LEN_MASK;
if (len < safe_len || sve_verify_vq_map()) {
pr_crit("CPU%d: SVE: vector length support mismatch\n",
smp_processor_id());
cpu_die_early();
}
/* Add checks on other ZCR bits here if necessary */
}
/*
* Run through the enabled system capabilities and enable() it on this CPU.
* The capabilities were decided based on the available CPUs at the boot time.
* Any new CPU should match the system wide status of the capability. If the
* new CPU doesn't have a capability which the system now has enabled, we
* cannot do anything to fix it up and could cause unexpected failures. So
* we park the CPU.
*/
static void verify_local_cpu_capabilities(void)
{
/*
* The capabilities with SCOPE_BOOT_CPU are checked from
* check_early_cpu_features(), as they need to be verified
* on all secondary CPUs.
*/
if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU))
cpu_die_early();
verify_local_elf_hwcaps(arm64_elf_hwcaps);
if (system_supports_32bit_el0())
verify_local_elf_hwcaps(compat_elf_hwcaps);
if (system_supports_sve())
verify_sve_features();
}
void check_local_cpu_capabilities(void)
{
/*
* All secondary CPUs should conform to the early CPU features
* in use by the kernel based on boot CPU.
*/
check_early_cpu_features();
/*
* If we haven't finalised the system capabilities, this CPU gets
* a chance to update the errata work arounds and local features.
* Otherwise, this CPU should verify that it has all the system
* advertised capabilities.
*/
if (!sys_caps_initialised)
update_cpu_capabilities(SCOPE_LOCAL_CPU);
else
verify_local_cpu_capabilities();
}
static void __init setup_boot_cpu_capabilities(void)
{
/* Detect capabilities with either SCOPE_BOOT_CPU or SCOPE_LOCAL_CPU */
update_cpu_capabilities(SCOPE_BOOT_CPU | SCOPE_LOCAL_CPU);
/* Enable the SCOPE_BOOT_CPU capabilities alone right away */
enable_cpu_capabilities(SCOPE_BOOT_CPU);
}
DEFINE_STATIC_KEY_FALSE(arm64_const_caps_ready);
EXPORT_SYMBOL(arm64_const_caps_ready);
static void __init mark_const_caps_ready(void)
{
static_branch_enable(&arm64_const_caps_ready);
}
bool this_cpu_has_cap(unsigned int n)
{
if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) {
const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
if (cap)
return cap->matches(cap, SCOPE_LOCAL_CPU);
}
return false;
}
void cpu_set_feature(unsigned int num)
{
WARN_ON(num >= MAX_CPU_FEATURES);
elf_hwcap |= BIT(num);
}
EXPORT_SYMBOL_GPL(cpu_set_feature);
bool cpu_have_feature(unsigned int num)
{
WARN_ON(num >= MAX_CPU_FEATURES);
return elf_hwcap & BIT(num);
}
EXPORT_SYMBOL_GPL(cpu_have_feature);
unsigned long cpu_get_elf_hwcap(void)
{
/*
* We currently only populate the first 32 bits of AT_HWCAP. Please
* note that for userspace compatibility we guarantee that bits 62
* and 63 will always be returned as 0.
*/
return lower_32_bits(elf_hwcap);
}
unsigned long cpu_get_elf_hwcap2(void)
{
return upper_32_bits(elf_hwcap);
}
static void __init setup_system_capabilities(void)
{
/*
* We have finalised the system-wide safe feature
* registers, finalise the capabilities that depend
* on it. Also enable all the available capabilities,
* that are not enabled already.
*/
update_cpu_capabilities(SCOPE_SYSTEM);
enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
}
void __init setup_cpu_features(void)
{
u32 cwg;
setup_system_capabilities();
mark_const_caps_ready();
setup_elf_hwcaps(arm64_elf_hwcaps);
if (system_supports_32bit_el0())
setup_elf_hwcaps(compat_elf_hwcaps);
if (system_uses_ttbr0_pan())
pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
sve_setup();
minsigstksz_setup();
/* Advertise that we have computed the system capabilities */
set_sys_caps_initialised();
/*
* Check for sane CTR_EL0.CWG value.
*/
cwg = cache_type_cwg();
if (!cwg)
pr_warn("No Cache Writeback Granule information, assuming %d\n",
ARCH_DMA_MINALIGN);
}
static bool __maybe_unused
cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
{
return (cpus_have_const_cap(ARM64_HAS_PAN) && !cpus_have_const_cap(ARM64_HAS_UAO));
}
static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)
{
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
}
/*
* We emulate only the following system register space.
* Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
* See Table C5-6 System instruction encodings for System register accesses,
* ARMv8 ARM(ARM DDI 0487A.f) for more details.
*/
static inline bool __attribute_const__ is_emulated(u32 id)
{
return (sys_reg_Op0(id) == 0x3 &&
sys_reg_CRn(id) == 0x0 &&
sys_reg_Op1(id) == 0x0 &&
(sys_reg_CRm(id) == 0 ||
((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
}
/*
* With CRm == 0, reg should be one of :
* MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
*/
static inline int emulate_id_reg(u32 id, u64 *valp)
{
switch (id) {
case SYS_MIDR_EL1:
*valp = read_cpuid_id();
break;
case SYS_MPIDR_EL1:
*valp = SYS_MPIDR_SAFE_VAL;
break;
case SYS_REVIDR_EL1:
/* IMPLEMENTATION DEFINED values are emulated with 0 */
*valp = 0;
break;
default:
return -EINVAL;
}
return 0;
}
static int emulate_sys_reg(u32 id, u64 *valp)
{
struct arm64_ftr_reg *regp;
if (!is_emulated(id))
return -EINVAL;
if (sys_reg_CRm(id) == 0)
return emulate_id_reg(id, valp);
regp = get_arm64_ftr_reg(id);
if (regp)
*valp = arm64_ftr_reg_user_value(regp);
else
/*
* The untracked registers are either IMPLEMENTATION DEFINED
* (e.g, ID_AFR0_EL1) or reserved RAZ.
*/
*valp = 0;
return 0;
}
int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
{
int rc;
u64 val;
rc = emulate_sys_reg(sys_reg, &val);
if (!rc) {
pt_regs_write_reg(regs, rt, val);
arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
}
return rc;
}
static int emulate_mrs(struct pt_regs *regs, u32 insn)
{
u32 sys_reg, rt;
/*
* sys_reg values are defined as used in mrs/msr instruction.
* shift the imm value to get the encoding.
*/
sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
return do_emulate_mrs(regs, sys_reg, rt);
}
static struct undef_hook mrs_hook = {
.instr_mask = 0xfff00000,
.instr_val = 0xd5300000,
.pstate_mask = PSR_AA32_MODE_MASK,
.pstate_val = PSR_MODE_EL0t,
.fn = emulate_mrs,
};
static int __init enable_mrs_emulation(void)
{
register_undef_hook(&mrs_hook);
return 0;
}
core_initcall(enable_mrs_emulation);
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
char *buf)
{
if (__meltdown_safe)
return sprintf(buf, "Not affected\n");
if (arm64_kernel_unmapped_at_el0())
return sprintf(buf, "Mitigation: PTI\n");
return sprintf(buf, "Vulnerable\n");
}
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