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authorSuzuki K. Poulose <suzuki.poulose@arm.com>2015-01-21 12:43:09 +0000
committerDavid Brown <david.brown@linaro.org>2015-12-03 16:53:42 -0800
commit8e0b6b082842f1a6e0b93e77b116d66336f7b2a6 (patch)
tree0e2dfa0eb22ece091130f8397dc65ceda2b16664
parent3171a7c2e276b6c9517de7dc574df490a87c9272 (diff)
downloadlinux-linaro-stable-8e0b6b082842f1a6e0b93e77b116d66336f7b2a6.tar.gz
arm64: Track system support for mixed endian EL0
commit 04597a65c5efc207257a736d339c6f2f5b00250f upstream. 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> Signed-off-by: David Brown <david.brown@linaro.org>
-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 5fe4befda1a5..3f0c53c45771 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -53,6 +53,8 @@ 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 16d6d032ecf1..618bf113a35f 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))
@@ -189,6 +210,7 @@ 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)