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arm64: cpufeature: Add scope for capability check
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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. The system uses the default scope associated with the
capability for initialising 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>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Suzuki K Poulose authored and Will Deacon committed Apr 25, 2016
1 parent 9981293 commit 92406f0
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Showing 3 changed files with 83 additions and 61 deletions.
9 changes: 8 additions & 1 deletion arch/arm64/include/asm/cpufeature.h
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Original file line number Diff line number Diff line change
Expand Up @@ -78,10 +78,17 @@ struct arm64_ftr_reg {
struct arm64_ftr_bits *ftr_bits;
};

/* scope of capability check */
enum {
SCOPE_SYSTEM,
SCOPE_LOCAL_CPU,
};

struct arm64_cpu_capabilities {
const char *desc;
u16 capability;
bool (*matches)(const struct arm64_cpu_capabilities *);
int def_scope; /* default scope */
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 */
Expand Down
4 changes: 3 additions & 1 deletion arch/arm64/kernel/cpu_errata.c
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Original file line number Diff line number Diff line change
Expand Up @@ -22,14 +22,16 @@
#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 scope)
{
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
return MIDR_IS_CPU_MODEL_RANGE(read_cpuid_id(), entry->midr_model,
entry->midr_range_min,
entry->midr_range_max);
}

#define MIDR_RANGE(model, min, max) \
.def_scope = SCOPE_LOCAL_CPU, \
.matches = is_affected_midr_range, \
.midr_model = model, \
.midr_range_min = min, \
Expand Down
131 changes: 72 additions & 59 deletions arch/arm64/kernel/cpufeature.c
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Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,8 @@ 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 struct arm64_ftr_bits ftr_id_aa64isar0[] = {
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
Expand Down Expand Up @@ -626,6 +627,49 @@ u64 read_system_reg(u32 id)
return regp->sys_val;
}

/*
* __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
* Read the system register on the current CPU
*/
static u64 __raw_read_system_reg(u32 sys_id)
{
switch (sys_id) {
case SYS_ID_PFR0_EL1: return read_cpuid(ID_PFR0_EL1);
case SYS_ID_PFR1_EL1: return read_cpuid(ID_PFR1_EL1);
case SYS_ID_DFR0_EL1: return read_cpuid(ID_DFR0_EL1);
case SYS_ID_MMFR0_EL1: return read_cpuid(ID_MMFR0_EL1);
case SYS_ID_MMFR1_EL1: return read_cpuid(ID_MMFR1_EL1);
case SYS_ID_MMFR2_EL1: return read_cpuid(ID_MMFR2_EL1);
case SYS_ID_MMFR3_EL1: return read_cpuid(ID_MMFR3_EL1);
case SYS_ID_ISAR0_EL1: return read_cpuid(ID_ISAR0_EL1);
case SYS_ID_ISAR1_EL1: return read_cpuid(ID_ISAR1_EL1);
case SYS_ID_ISAR2_EL1: return read_cpuid(ID_ISAR2_EL1);
case SYS_ID_ISAR3_EL1: return read_cpuid(ID_ISAR3_EL1);
case SYS_ID_ISAR4_EL1: return read_cpuid(ID_ISAR4_EL1);
case SYS_ID_ISAR5_EL1: return read_cpuid(ID_ISAR4_EL1);
case SYS_MVFR0_EL1: return read_cpuid(MVFR0_EL1);
case SYS_MVFR1_EL1: return read_cpuid(MVFR1_EL1);
case SYS_MVFR2_EL1: return read_cpuid(MVFR2_EL1);

case SYS_ID_AA64PFR0_EL1: return read_cpuid(ID_AA64PFR0_EL1);
case SYS_ID_AA64PFR1_EL1: return read_cpuid(ID_AA64PFR0_EL1);
case SYS_ID_AA64DFR0_EL1: return read_cpuid(ID_AA64DFR0_EL1);
case SYS_ID_AA64DFR1_EL1: return read_cpuid(ID_AA64DFR0_EL1);
case SYS_ID_AA64MMFR0_EL1: return read_cpuid(ID_AA64MMFR0_EL1);
case SYS_ID_AA64MMFR1_EL1: return read_cpuid(ID_AA64MMFR1_EL1);
case SYS_ID_AA64MMFR2_EL1: return read_cpuid(ID_AA64MMFR2_EL1);
case SYS_ID_AA64ISAR0_EL1: return read_cpuid(ID_AA64ISAR0_EL1);
case SYS_ID_AA64ISAR1_EL1: return read_cpuid(ID_AA64ISAR1_EL1);

case SYS_CNTFRQ_EL0: return read_cpuid(CNTFRQ_EL0);
case SYS_CTR_EL0: return read_cpuid(CTR_EL0);
case SYS_DCZID_EL0: return read_cpuid(DCZID_EL0);
default:
BUG();
return 0;
}
}

#include <linux/irqchip/arm-gic-v3.h>

static bool
Expand All @@ -637,19 +681,24 @@ 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);
WARN_ON(scope == SCOPE_LOCAL_CPU && preemptible());
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();
Expand All @@ -660,7 +709,7 @@ 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;
Expand All @@ -672,7 +721,7 @@ 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();
}
Expand All @@ -681,6 +730,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "GIC system register CPU interface",
.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
.def_scope = SCOPE_SYSTEM,
.matches = has_useable_gicv3_cpuif,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.field_pos = ID_AA64PFR0_GIC_SHIFT,
Expand All @@ -691,6 +741,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "Privileged Access Never",
.capability = ARM64_HAS_PAN,
.def_scope = SCOPE_SYSTEM,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64MMFR1_EL1,
.field_pos = ID_AA64MMFR1_PAN_SHIFT,
Expand All @@ -703,6 +754,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "LSE atomic instructions",
.capability = ARM64_HAS_LSE_ATOMICS,
.def_scope = SCOPE_SYSTEM,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64ISAR0_EL1,
.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
Expand All @@ -713,12 +765,14 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "Software prefetching using PRFM",
.capability = ARM64_HAS_NO_HW_PREFETCH,
.def_scope = SCOPE_SYSTEM,
.matches = has_no_hw_prefetch,
},
#ifdef CONFIG_ARM64_UAO
{
.desc = "User Access Override",
.capability = ARM64_HAS_UAO,
.def_scope = SCOPE_SYSTEM,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64MMFR2_EL1,
.field_pos = ID_AA64MMFR2_UAO_SHIFT,
Expand All @@ -729,17 +783,20 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
#ifdef CONFIG_ARM64_PAN
{
.capability = ARM64_ALT_PAN_NOT_UAO,
.def_scope = SCOPE_SYSTEM,
.matches = cpufeature_pan_not_uao,
},
#endif /* CONFIG_ARM64_PAN */
{
.desc = "Virtualization Host Extensions",
.capability = ARM64_HAS_VIRT_HOST_EXTN,
.def_scope = SCOPE_SYSTEM,
.matches = runs_at_el2,
},
{
.desc = "32-bit EL0 Support",
.capability = ARM64_HAS_32BIT_EL0,
.def_scope = SCOPE_SYSTEM,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64PFR0_EL1,
.sign = FTR_UNSIGNED,
Expand All @@ -752,6 +809,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
#define HWCAP_CAP(reg, field, s, min_value, type, cap) \
{ \
.desc = #cap, \
.def_scope = SCOPE_SYSTEM, \
.matches = has_cpuid_feature, \
.sys_reg = reg, \
.field_pos = field, \
Expand Down Expand Up @@ -834,15 +892,15 @@ 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, hwcaps->def_scope))
cap_set_elf_hwcap(hwcaps);
}

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, caps->def_scope))
continue;

if (!cpus_have_cap(caps->capability) && caps->desc)
Expand Down Expand Up @@ -878,48 +936,6 @@ static inline void set_sys_caps_initialised(void)
sys_caps_initialised = true;
}

/*
* __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
*/
static u64 __raw_read_system_reg(u32 sys_id)
{
switch (sys_id) {
case SYS_ID_PFR0_EL1: return read_cpuid(ID_PFR0_EL1);
case SYS_ID_PFR1_EL1: return read_cpuid(ID_PFR1_EL1);
case SYS_ID_DFR0_EL1: return read_cpuid(ID_DFR0_EL1);
case SYS_ID_MMFR0_EL1: return read_cpuid(ID_MMFR0_EL1);
case SYS_ID_MMFR1_EL1: return read_cpuid(ID_MMFR1_EL1);
case SYS_ID_MMFR2_EL1: return read_cpuid(ID_MMFR2_EL1);
case SYS_ID_MMFR3_EL1: return read_cpuid(ID_MMFR3_EL1);
case SYS_ID_ISAR0_EL1: return read_cpuid(ID_ISAR0_EL1);
case SYS_ID_ISAR1_EL1: return read_cpuid(ID_ISAR1_EL1);
case SYS_ID_ISAR2_EL1: return read_cpuid(ID_ISAR2_EL1);
case SYS_ID_ISAR3_EL1: return read_cpuid(ID_ISAR3_EL1);
case SYS_ID_ISAR4_EL1: return read_cpuid(ID_ISAR4_EL1);
case SYS_ID_ISAR5_EL1: return read_cpuid(ID_ISAR4_EL1);
case SYS_MVFR0_EL1: return read_cpuid(MVFR0_EL1);
case SYS_MVFR1_EL1: return read_cpuid(MVFR1_EL1);
case SYS_MVFR2_EL1: return read_cpuid(MVFR2_EL1);

case SYS_ID_AA64PFR0_EL1: return read_cpuid(ID_AA64PFR0_EL1);
case SYS_ID_AA64PFR1_EL1: return read_cpuid(ID_AA64PFR0_EL1);
case SYS_ID_AA64DFR0_EL1: return read_cpuid(ID_AA64DFR0_EL1);
case SYS_ID_AA64DFR1_EL1: return read_cpuid(ID_AA64DFR0_EL1);
case SYS_ID_AA64MMFR0_EL1: return read_cpuid(ID_AA64MMFR0_EL1);
case SYS_ID_AA64MMFR1_EL1: return read_cpuid(ID_AA64MMFR1_EL1);
case SYS_ID_AA64MMFR2_EL1: return read_cpuid(ID_AA64MMFR2_EL1);
case SYS_ID_AA64ISAR0_EL1: return read_cpuid(ID_AA64ISAR0_EL1);
case SYS_ID_AA64ISAR1_EL1: return read_cpuid(ID_AA64ISAR1_EL1);

case SYS_CNTFRQ_EL0: return read_cpuid(CNTFRQ_EL0);
case SYS_CTR_EL0: return read_cpuid(CTR_EL0);
case SYS_DCZID_EL0: return read_cpuid(DCZID_EL0);
default:
BUG();
return 0;
}
}

/*
* Check for CPU features that are used in early boot
* based on the Boot CPU value.
Expand All @@ -934,28 +950,25 @@ 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_LOCAL_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_LOCAL_CPU)) {
pr_crit("CPU%d: missing feature: %s\n",
smp_processor_id(), caps->desc);
cpu_die_early();
Expand Down Expand Up @@ -1026,7 +1039,7 @@ 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));
}

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