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arm64: capabilities: Add support for checks based on a list of MIDRs

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Add helpers for detecting an errata on list of midr ranges
of affected CPUs, with the same work around.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Suzuki K Poulose 2018-03-26 15:12:45 +01:00 committed by Will Deacon
parent 1df310505d
commit be5b299830
4 changed files with 60 additions and 41 deletions
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1
arch/arm64/include/asm/cpufeature.h
View File

@ -314,6 +314,7 @@ struct arm64_cpu_capabilities {
} * const fixed_revs;
};
const struct midr_range *midr_range_list;
struct { /* Feature register checking */
u32 sys_reg;
u8 field_pos;

9
arch/arm64/include/asm/cputype.h
View File

@ -147,6 +147,15 @@ static inline bool is_midr_in_range(u32 midr, struct midr_range const *range)
range->rv_min, range->rv_max);
}
static inline bool
is_midr_in_range_list(u32 midr, struct midr_range const *ranges)
{
while (ranges->model)
if (is_midr_in_range(midr, ranges++))
return true;
return false;
}
/*
* The CPU ID never changes at run time, so we might as well tell the
* compiler that it's constant. Use this function to read the CPU ID

81
arch/arm64/kernel/cpu_errata.c
View File

@ -40,6 +40,14 @@ is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
return true;
}
static bool __maybe_unused
is_affected_midr_range_list(const struct arm64_cpu_capabilities *entry,
int scope)
{
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
return is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list);
}
static bool __maybe_unused
is_kryo_midr(const struct arm64_cpu_capabilities *entry, int scope)
{
@ -250,6 +258,10 @@ qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry)
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
CAP_MIDR_RANGE(model, v_min, r_min, v_max, r_max)
#define CAP_MIDR_RANGE_LIST(list) \
.matches = is_affected_midr_range_list, \
.midr_range_list = list
/* Errata affecting a range of revisions of given model variant */
#define ERRATA_MIDR_REV_RANGE(m, var, r_min, r_max) \
ERRATA_MIDR_RANGE(m, var, r_min, var, r_max)
@ -263,6 +275,35 @@ qcom_enable_link_stack_sanitization(const struct arm64_cpu_capabilities *entry)
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
CAP_MIDR_ALL_VERSIONS(model)
/* Errata affecting a list of midr ranges, with same work around */
#define ERRATA_MIDR_RANGE_LIST(midr_list) \
.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \
CAP_MIDR_RANGE_LIST(midr_list)
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
/*
* List of CPUs where we need to issue a psci call to
* harden the branch predictor.
*/
static const struct midr_range arm64_bp_harden_smccc_cpus[] = {
MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
{},
};
static const struct midr_range qcom_bp_harden_cpus[] = {
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
{},
};
#endif
const struct arm64_cpu_capabilities arm64_errata[] = {
#if defined(CONFIG_ARM64_ERRATUM_826319) || \
defined(CONFIG_ARM64_ERRATUM_827319) || \
@ -406,51 +447,17 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A57),
ERRATA_MIDR_RANGE_LIST(arm64_bp_harden_smccc_cpus),
.cpu_enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A72),
.cpu_enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A73),
.cpu_enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
.cpu_enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
.cpu_enable = qcom_enable_link_stack_sanitization,
},
{
.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1),
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
.cpu_enable = qcom_enable_link_stack_sanitization,
},
{
.capability = ARM64_HARDEN_BP_POST_GUEST_EXIT,
ERRATA_MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR),
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
.cpu_enable = enable_smccc_arch_workaround_1,
},
{
.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
ERRATA_MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
.cpu_enable = enable_smccc_arch_workaround_1,
ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus),
},
#endif
{

10
arch/arm64/kernel/cpufeature.c
View File

@ -882,6 +882,11 @@ 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),
};
char const *str = "command line option";
/*
@ -906,11 +911,8 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
return true;
/* Don't force KPTI for CPUs that are not vulnerable */
switch (read_cpuid_id() & MIDR_CPU_MODEL_MASK) {
case MIDR_CAVIUM_THUNDERX2:
case MIDR_BRCM_VULCAN:
if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
return false;
}
/* Defer to CPU feature registers */
return !has_cpuid_feature(entry, scope);