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authorSuzuki K. Poulose <suzuki.poulose@arm.com>2015-01-21 12:43:09 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2015-01-23 17:02:19 +0000
commit04597a65c5efc207257a736d339c6f2f5b00250f (patch)
tree953d59d84ff90345401756301e9eaeee2a4d580f /arch/arm64
parent78d51e0b8b57728099a3da74f4a10b6f8c71b764 (diff)
arm64: Track system support for mixed endian EL0
This patch keeps track of the mixed endian EL0 support across the system and provides helper functions to export it. The status is a boolean indicating whether all the CPUs on the system supports mixed endian at EL0. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
-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 07547ccc1f2b..b6c16d5f622f 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 8adb986a3086..ee6403df9fe4 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 49782282a027..929855691dae 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)