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-rw-r--r--arch/arm64/include/asm/cpufeature.h2
-rw-r--r--arch/arm64/include/asm/cputype.h14
-rw-r--r--arch/arm64/kernel/cpuinfo.c22
3 files changed, 38 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 07547ccc1f2..b6c16d5f622 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -52,6 +52,8 @@ static inline void cpus_set_cap(unsigned int num)
}
void check_local_cpu_errata(void);
+bool cpu_supports_mixed_endian_el0(void);
+bool system_supports_mixed_endian_el0(void);
#endif /* __ASSEMBLY__ */
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 8adb986a308..ee6403df9fe 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -72,6 +72,15 @@
#define APM_CPU_PART_POTENZA 0x000
+#define ID_AA64MMFR0_BIGENDEL0_SHIFT 16
+#define ID_AA64MMFR0_BIGENDEL0_MASK (0xf << ID_AA64MMFR0_BIGENDEL0_SHIFT)
+#define ID_AA64MMFR0_BIGENDEL0(mmfr0) \
+ (((mmfr0) & ID_AA64MMFR0_BIGENDEL0_MASK) >> ID_AA64MMFR0_BIGENDEL0_SHIFT)
+#define ID_AA64MMFR0_BIGEND_SHIFT 8
+#define ID_AA64MMFR0_BIGEND_MASK (0xf << ID_AA64MMFR0_BIGEND_SHIFT)
+#define ID_AA64MMFR0_BIGEND(mmfr0) \
+ (((mmfr0) & ID_AA64MMFR0_BIGEND_MASK) >> ID_AA64MMFR0_BIGEND_SHIFT)
+
#ifndef __ASSEMBLY__
/*
@@ -104,6 +113,11 @@ static inline u32 __attribute_const__ read_cpuid_cachetype(void)
return read_cpuid(CTR_EL0);
}
+static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
+{
+ return (ID_AA64MMFR0_BIGEND(mmfr0) == 0x1) ||
+ (ID_AA64MMFR0_BIGENDEL0(mmfr0) == 0x1);
+}
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 49782282a02..929855691da 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -35,6 +35,7 @@
*/
DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
static struct cpuinfo_arm64 boot_cpu_data;
+static bool mixed_endian_el0 = true;
static char *icache_policy_str[] = {
[ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
@@ -68,6 +69,26 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
}
+bool cpu_supports_mixed_endian_el0(void)
+{
+ return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
+}
+
+bool system_supports_mixed_endian_el0(void)
+{
+ return mixed_endian_el0;
+}
+
+static void update_mixed_endian_el0_support(struct cpuinfo_arm64 *info)
+{
+ mixed_endian_el0 &= id_aa64mmfr0_mixed_endian_el0(info->reg_id_aa64mmfr0);
+}
+
+static void update_cpu_features(struct cpuinfo_arm64 *info)
+{
+ update_mixed_endian_el0_support(info);
+}
+
static int check_reg_mask(char *name, u64 mask, u64 boot, u64 cur, int cpu)
{
if ((boot & mask) == (cur & mask))
@@ -215,6 +236,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
cpuinfo_detect_icache_policy(info);
check_local_cpu_errata();
+ update_cpu_features(info);
}
void cpuinfo_store_cpu(void)