From 04597a65c5efc207257a736d339c6f2f5b00250f Mon Sep 17 00:00:00 2001 From: "Suzuki K. Poulose" Date: Wed, 21 Jan 2015 12:43:09 +0000 Subject: [PATCH] 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 Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/include/asm/cputype.h | 14 ++++++++++++++ arch/arm64/kernel/cpuinfo.c | 22 ++++++++++++++++++++++ 3 files changed, 38 insertions(+) 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) -- 2.20.1