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arm64: cpufeatures: Check ICC_EL1_SRE.SRE before enabling ARM64_HAS_SYSREG_GIC_CPUIF

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As the firmware (or the hypervisor) may have disabled SRE access,
check that SRE can actually be enabled before declaring that we
do have that capability.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Marc Zyngier 2015-09-30 11:50:04 +01:00
parent 7cabd0086a
commit 963fcd4095
1 changed files with 18 additions and 1 deletions
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19
arch/arm64/kernel/cpufeature.c
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@ -23,6 +23,8 @@
#include <asm/cpufeature.h> #include <asm/cpufeature.h>
#include <asm/processor.h> #include <asm/processor.h>
#include <linux/irqchip/arm-gic-v3.h>
static bool static bool
feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry) feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
{ {
@ -45,11 +47,26 @@ __ID_FEAT_CHK(id_aa64pfr0);
__ID_FEAT_CHK(id_aa64mmfr1); __ID_FEAT_CHK(id_aa64mmfr1);
__ID_FEAT_CHK(id_aa64isar0); __ID_FEAT_CHK(id_aa64isar0);
static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry)
{
bool has_sre;
if (!has_id_aa64pfr0_feature(entry))
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 const struct arm64_cpu_capabilities arm64_features[] = { static const struct arm64_cpu_capabilities arm64_features[] = {
{ {
.desc = "GIC system register CPU interface", .desc = "GIC system register CPU interface",
.capability = ARM64_HAS_SYSREG_GIC_CPUIF, .capability = ARM64_HAS_SYSREG_GIC_CPUIF,
.matches = has_id_aa64pfr0_feature, .matches = has_useable_gicv3_cpuif,
.field_pos = 24, .field_pos = 24,
.min_field_value = 1, .min_field_value = 1,
}, },