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.
Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/kernel/cpufeature.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 3c9aed3..305f30dc 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -23,6 +23,8 @@ #include <asm/cpufeature.h> #include <asm/processor.h> +#include <linux/irqchip/arm-gic-v3.h> + static bool 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_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[] = { { .desc = "GIC system register CPU interface", .capability = ARM64_HAS_SYSREG_GIC_CPUIF, - .matches = has_id_aa64pfr0_feature, + .matches = has_useable_gicv3_cpuif, .field_pos = 24, .min_field_value = 1, }, -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
