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authorSuzuki K Poulose <suzuki.poulose@arm.com>2016-04-18 10:28:36 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-10 08:52:09 +0200
commitfdbd625224311d5f622f0a4251114ba63293a5d5 (patch)
tree04f6be2bb6d8be666f021a02b563ca94f89bbb5f /arch/arm64
parent4ff0d84e6d990383f0709e363417315a95c20255 (diff)
arm64: cpufeature: Track 32bit EL0 support
commit 042446a31e3803d81c7e618dd80928dc3dce70c5 upstream. 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> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/cpufeature.h8
-rw-r--r--arch/arm64/include/asm/sysreg.h1
-rw-r--r--arch/arm64/kernel/cpufeature.c8
3 files changed, 16 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 8884b5d5f48c..ad83c245781c 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -31,8 +31,9 @@
#define ARM64_WORKAROUND_CAVIUM_23154 6
#define ARM64_WORKAROUND_834220 7
#define ARM64_WORKAROUND_CAVIUM_27456 8
+#define ARM64_HAS_32BIT_EL0 9
-#define ARM64_NCAPS 9
+#define ARM64_NCAPS 10
#ifndef __ASSEMBLY__
@@ -180,6 +181,11 @@ 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/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index d48ab5b41f52..50150320f80d 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -109,6 +109,7 @@
#define ID_AA64PFR0_ASIMD_SUPPORTED 0x0
#define ID_AA64PFR0_EL1_64BIT_ONLY 0x1
#define ID_AA64PFR0_EL0_64BIT_ONLY 0x1
+#define ID_AA64PFR0_EL0_32BIT_64BIT 0x2
/* id_aa64mmfr0 */
#define ID_AA64MMFR0_TGRAN4_SHIFT 28
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2735bf814592..c1eddc07d996 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -653,6 +653,14 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.min_field_value = 2,
},
#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
+ {
+ .desc = "32-bit EL0 Support",
+ .capability = ARM64_HAS_32BIT_EL0,
+ .matches = has_cpuid_feature,
+ .sys_reg = SYS_ID_AA64PFR0_EL1,
+ .field_pos = ID_AA64PFR0_EL0_SHIFT,
+ .min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
+ },
{},
};