[PATCH v3 1/3] arm64: Modify _midr_range() functions to read MIDR/REVIDR internally
Shameer Kolothum
shameerali.kolothum.thodi at huawei.com
Mon Dec 9 03:53:09 PST 2024
These changes lay the groundwork for adding support for guest kernels,
allowing them to leverage target CPU implementations provided by the
VMM.
No functional changes intended.
Suggested-by: Oliver Upton <oliver.upton at linux.dev>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
---
arch/arm64/include/asm/cputype.h | 28 ++++++++++++++--------------
arch/arm64/include/asm/mmu.h | 3 +--
arch/arm64/kernel/cpu_errata.c | 23 +++++++++++++----------
arch/arm64/kernel/cpufeature.c | 6 +++---
arch/arm64/kernel/proton-pack.c | 17 ++++++++---------
arch/arm64/kvm/vgic/vgic-v3.c | 2 +-
drivers/clocksource/arm_arch_timer.c | 2 +-
7 files changed, 41 insertions(+), 40 deletions(-)
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 488f8e751349..dcf0e1ce892d 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -229,6 +229,16 @@
#define read_cpuid(reg) read_sysreg_s(SYS_ ## reg)
+/*
+ * 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
+ * rather than directly reading processor_id or read_cpuid() directly.
+ */
+static inline u32 __attribute_const__ read_cpuid_id(void)
+{
+ return read_cpuid(MIDR_EL1);
+}
+
/*
* Represent a range of MIDR values for a given CPU model and a
* range of variant/revision values.
@@ -264,31 +274,21 @@ static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min,
return _model == model && rv >= rv_min && rv <= rv_max;
}
-static inline bool is_midr_in_range(u32 midr, struct midr_range const *range)
+static inline bool is_midr_in_range(struct midr_range const *range)
{
- return midr_is_cpu_model_range(midr, range->model,
+ return midr_is_cpu_model_range(read_cpuid_id(), range->model,
range->rv_min, range->rv_max);
}
static inline bool
-is_midr_in_range_list(u32 midr, struct midr_range const *ranges)
+is_midr_in_range_list(struct midr_range const *ranges)
{
while (ranges->model)
- if (is_midr_in_range(midr, ranges++))
+ if (is_midr_in_range(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
- * rather than directly reading processor_id or read_cpuid() directly.
- */
-static inline u32 __attribute_const__ read_cpuid_id(void)
-{
- return read_cpuid(MIDR_EL1);
-}
-
static inline u64 __attribute_const__ read_cpuid_mpidr(void)
{
return read_cpuid(MPIDR_EL1);
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 2ec96d91acc6..bfd303e074be 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -101,8 +101,7 @@ static inline bool kaslr_requires_kpti(void)
if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
extern const struct midr_range cavium_erratum_27456_cpus[];
- if (is_midr_in_range_list(read_cpuid_id(),
- cavium_erratum_27456_cpus))
+ if (is_midr_in_range_list(cavium_erratum_27456_cpus))
return false;
}
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index a78f247029ae..929685c00263 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -15,30 +15,34 @@
#include <asm/smp_plat.h>
static bool __maybe_unused
-is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
+__is_affected_midr_range(const struct arm64_cpu_capabilities *entry,
+ u32 midr, u32 revidr)
{
const struct arm64_midr_revidr *fix;
- u32 midr = read_cpuid_id(), revidr;
-
- WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
- if (!is_midr_in_range(midr, &entry->midr_range))
+ if (!is_midr_in_range(&entry->midr_range))
return false;
midr &= MIDR_REVISION_MASK | MIDR_VARIANT_MASK;
- revidr = read_cpuid(REVIDR_EL1);
for (fix = entry->fixed_revs; fix && fix->revidr_mask; fix++)
if (midr == fix->midr_rv && (revidr & fix->revidr_mask))
return false;
-
return true;
}
+static bool __maybe_unused
+is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
+{
+ WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+ return __is_affected_midr_range(entry, read_cpuid_id(),
+ read_cpuid(REVIDR_EL1));
+}
+
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);
+ return is_midr_in_range_list(entry->midr_range_list);
}
static bool __maybe_unused
@@ -186,12 +190,11 @@ static bool __maybe_unused
has_neoverse_n1_erratum_1542419(const struct arm64_cpu_capabilities *entry,
int scope)
{
- u32 midr = read_cpuid_id();
bool has_dic = read_cpuid_cachetype() & BIT(CTR_EL0_DIC_SHIFT);
const struct midr_range range = MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1);
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
- return is_midr_in_range(midr, &range) && has_dic;
+ return is_midr_in_range(&range) && has_dic;
}
#ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6ce71f444ed8..4cc4ae16b28d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1783,7 +1783,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
char const *str = "kpti command line option";
bool meltdown_safe;
- meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
+ meltdown_safe = is_midr_in_range_list(kpti_safe_list);
/* Defer to CPU feature registers */
if (has_cpuid_feature(entry, scope))
@@ -1853,7 +1853,7 @@ static bool has_nv1(const struct arm64_cpu_capabilities *entry, int scope)
return (__system_matches_cap(ARM64_HAS_NESTED_VIRT) &&
!(has_cpuid_feature(entry, scope) ||
- is_midr_in_range_list(read_cpuid_id(), nv1_ni_list)));
+ is_midr_in_range_list(nv1_ni_list)));
}
#if defined(ID_AA64MMFR0_EL1_TGRAN_LPA2) && defined(ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_LPA2)
@@ -2036,7 +2036,7 @@ static bool cpu_has_broken_dbm(void)
{},
};
- return is_midr_in_range_list(read_cpuid_id(), cpus);
+ return is_midr_in_range_list(cpus);
}
static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index da53722f95d4..a573fa40d4b6 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -172,7 +172,7 @@ static enum mitigation_state spectre_v2_get_cpu_hw_mitigation_state(void)
return SPECTRE_UNAFFECTED;
/* Alternatively, we have a list of unaffected CPUs */
- if (is_midr_in_range_list(read_cpuid_id(), spectre_v2_safe_list))
+ if (is_midr_in_range_list(spectre_v2_safe_list))
return SPECTRE_UNAFFECTED;
return SPECTRE_VULNERABLE;
@@ -331,7 +331,7 @@ bool has_spectre_v3a(const struct arm64_cpu_capabilities *entry, int scope)
};
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
- return is_midr_in_range_list(read_cpuid_id(), spectre_v3a_unsafe_list);
+ return is_midr_in_range_list(spectre_v3a_unsafe_list);
}
void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
@@ -475,7 +475,7 @@ static enum mitigation_state spectre_v4_get_cpu_hw_mitigation_state(void)
{ /* sentinel */ },
};
- if (is_midr_in_range_list(read_cpuid_id(), spectre_v4_safe_list))
+ if (is_midr_in_range_list(spectre_v4_safe_list))
return SPECTRE_UNAFFECTED;
/* CPU features are detected first */
@@ -878,13 +878,13 @@ u8 spectre_bhb_loop_affected(int scope)
{},
};
- if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list))
+ if (is_midr_in_range_list(spectre_bhb_k32_list))
k = 32;
- else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list))
+ else if (is_midr_in_range_list(spectre_bhb_k24_list))
k = 24;
- else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list))
+ else if (is_midr_in_range_list(spectre_bhb_k11_list))
k = 11;
- else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list))
+ else if (is_midr_in_range_list(spectre_bhb_k8_list))
k = 8;
max_bhb_k = max(max_bhb_k, k);
@@ -926,8 +926,7 @@ static bool is_spectre_bhb_fw_affected(int scope)
MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
{},
};
- bool cpu_in_list = is_midr_in_range_list(read_cpuid_id(),
- spectre_bhb_firmware_mitigated_list);
+ bool cpu_in_list = is_midr_in_range_list(spectre_bhb_firmware_mitigated_list);
if (scope != SCOPE_LOCAL_CPU)
return system_affected;
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index f267bc2486a1..b815d910c7e4 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -632,7 +632,7 @@ static const struct midr_range broken_seis[] = {
static bool vgic_v3_broken_seis(void)
{
return ((kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_SEIS_MASK) &&
- is_midr_in_range_list(read_cpuid_id(), broken_seis));
+ is_midr_in_range_list(broken_seis));
}
/**
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 808f259781fd..981a578043a5 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -842,7 +842,7 @@ static u64 __arch_timer_check_delta(void)
{},
};
- if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {
+ if (is_midr_in_range_list(broken_cval_midrs)) {
pr_warn_once("Broken CNTx_CVAL_EL1, using 31 bit TVAL instead.\n");
return CLOCKSOURCE_MASK(31);
}
--
2.47.0
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