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Subject[PATCH 1/5] arm64: cpufeature: Add scope for capability check
Date
Add scope parameter to the arm64_cpu_capabilities::matches(),
so that this can be reused for checking the capability on a
given CPU vs the system wide. By default, the system uses
'system' wide values for setting the CPU_HWCAPs and ELF_HWCAPs.

Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/cpufeature.h | 8 +++++++-
arch/arm64/kernel/cpu_errata.c | 2 +-
arch/arm64/kernel/cpufeature.c | 37 +++++++++++++++++++----------------
3 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index ca8fb4b..5f10344 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -78,10 +78,16 @@ struct arm64_ftr_reg {
struct arm64_ftr_bits *ftr_bits;
};

+/* scope of capability check */
+enum {
+ SCOPE_SYSTEM,
+ SCOPE_CPU,
+};
+
struct arm64_cpu_capabilities {
const char *desc;
u16 capability;
- bool (*matches)(const struct arm64_cpu_capabilities *);
+ bool (*matches)(const struct arm64_cpu_capabilities *caps, int scope);
void (*enable)(void *); /* Called on all active CPUs */
union {
struct { /* To be used for erratum handling only */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 06afd04..2fd5780 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -22,7 +22,7 @@
#include <asm/cpufeature.h>

static bool __maybe_unused
-is_affected_midr_range(const struct arm64_cpu_capabilities *entry)
+is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int __unused)
{
return MIDR_IS_CPU_MODEL_RANGE(read_cpuid_id(), entry->midr_model,
entry->midr_range_min,
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c31be96..d3ee1df 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -71,7 +71,9 @@ DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);

/* meta feature for alternatives */
static bool __maybe_unused
-cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry);
+cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
+
+static u64 __raw_read_system_reg(u32 sys_id);

static struct arm64_ftr_bits ftr_id_aa64isar0[] = {
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
@@ -633,19 +635,23 @@ feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
}

static bool
-has_cpuid_feature(const struct arm64_cpu_capabilities *entry)
+has_cpuid_feature(const struct arm64_cpu_capabilities *entry, int scope)
{
u64 val;

- val = read_system_reg(entry->sys_reg);
+ if (scope == SCOPE_SYSTEM)
+ val = read_system_reg(entry->sys_reg);
+ else
+ val = __raw_read_system_reg(entry->sys_reg);
+
return feature_matches(val, entry);
}

-static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry)
+static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry, int scope)
{
bool has_sre;

- if (!has_cpuid_feature(entry))
+ if (!has_cpuid_feature(entry, scope))
return false;

has_sre = gic_enable_sre();
@@ -656,7 +662,7 @@ static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry)
return has_sre;
}

-static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry)
+static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int __unused)
{
u32 midr = read_cpuid_id();
u32 rv_min, rv_max;
@@ -668,7 +674,7 @@ static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry)
return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX, rv_min, rv_max);
}

-static bool runs_at_el2(const struct arm64_cpu_capabilities *entry)
+static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
{
return is_kernel_in_hyp_mode();
}
@@ -830,7 +836,7 @@ static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
{
for (; hwcaps->matches; hwcaps++)
- if (hwcaps->matches(hwcaps))
+ if (hwcaps->matches(hwcaps, SCOPE_SYSTEM))
cap_set_elf_hwcap(hwcaps);
}

@@ -838,7 +844,7 @@ void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info)
{
for (; caps->matches; caps++) {
- if (!caps->matches(caps))
+ if (!caps->matches(caps, SCOPE_SYSTEM))
continue;

if (!cpus_have_cap(caps->capability) && caps->desc)
@@ -929,28 +935,25 @@ static void
verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
{

- for (; caps->matches; caps++) {
- if (!cpus_have_elf_hwcap(caps))
- continue;
- if (!feature_matches(__raw_read_system_reg(caps->sys_reg), caps)) {
+ for (; caps->matches; caps++)
+ if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_CPU)) {
pr_crit("CPU%d: missing HWCAP: %s\n",
smp_processor_id(), caps->desc);
cpu_die_early();
}
- }
}

static void
verify_local_cpu_features(const struct arm64_cpu_capabilities *caps)
{
for (; caps->matches; caps++) {
- if (!cpus_have_cap(caps->capability) || !caps->sys_reg)
+ if (!cpus_have_cap(caps->capability))
continue;
/*
* If the new CPU misses an advertised feature, we cannot proceed
* further, park the cpu.
*/
- if (!feature_matches(__raw_read_system_reg(caps->sys_reg), caps)) {
+ if (!caps->matches(caps, SCOPE_CPU)) {
pr_crit("CPU%d: missing feature: %s\n",
smp_processor_id(), caps->desc);
cpu_die_early();
@@ -1021,7 +1024,7 @@ void __init setup_cpu_features(void)
}

static bool __maybe_unused
-cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry)
+cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
{
return (cpus_have_cap(ARM64_HAS_PAN) && !cpus_have_cap(ARM64_HAS_UAO));
}
--
1.7.9.5
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