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authorSuzuki K Poulose <suzuki.poulose@arm.com>2016-04-18 10:28:36 +0100
committerWill Deacon <will.deacon@arm.com>2016-04-20 12:22:42 +0100
commit042446a31e3803d81c7e618dd80928dc3dce70c5 (patch)
treeb77500a46468c4d71d1aef06691eb0331f24c4cd
parenta6dc3cd718ec2a19b8ca812087666899852af78f (diff)
downloadlinux-042446a31e3803d81c7e618dd80928dc3dce70c5.tar.bz2
arm64: cpufeature: Track 32bit EL0 support
Add cpu_hwcap bit for keeping track of the support for 32bit EL0. Tested-by: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/include/asm/cpufeature.h8
-rw-r--r--arch/arm64/kernel/cpufeature.c9
2 files changed, 16 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 7f64285e4ef7..ca8fb4bcfb1a 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -35,8 +35,9 @@
#define ARM64_ALT_PAN_NOT_UAO 10
#define ARM64_HAS_VIRT_HOST_EXTN 11
#define ARM64_WORKAROUND_CAVIUM_27456 12
+#define ARM64_HAS_32BIT_EL0 13
-#define ARM64_NCAPS 13
+#define ARM64_NCAPS 14
#ifndef __ASSEMBLY__
@@ -192,6 +193,11 @@ static inline bool cpu_supports_mixed_endian_el0(void)
return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
}
+static inline bool system_supports_32bit_el0(void)
+{
+ return cpus_have_cap(ARM64_HAS_32BIT_EL0);
+}
+
static inline bool system_supports_mixed_endian_el0(void)
{
return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9097ce9244e3..40a23f24559d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -737,6 +737,15 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.capability = ARM64_HAS_VIRT_HOST_EXTN,
.matches = runs_at_el2,
},
+ {
+ .desc = "32-bit EL0 Support",
+ .capability = ARM64_HAS_32BIT_EL0,
+ .matches = has_cpuid_feature,
+ .sys_reg = SYS_ID_AA64PFR0_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64PFR0_EL0_SHIFT,
+ .min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
+ },
{},
};