[PATCHv4 11/24] arm64: Cleanup mixed endian support detection

From: Suzuki K. Poulose
Date: Mon Oct 19 2015 - 09:25:41 EST


Make use of the system wide safe register to decide the support
for mixed endian.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx>
---
arch/arm64/include/asm/cpufeature.h | 12 ++++++++++--
arch/arm64/kernel/cpufeature.c | 22 ----------------------
2 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index c882d46..2797876 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -141,11 +141,19 @@ void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info);
void check_local_cpu_errata(void);
void check_local_cpu_features(void);
-bool cpu_supports_mixed_endian_el0(void);
-bool system_supports_mixed_endian_el0(void);

u64 read_system_reg(u32 id);

+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_mixed_endian_el0(void)
+{
+ return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
+}
+
#endif /* __ASSEMBLY__ */

#endif
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index b4656ca..a90a64d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -26,7 +26,6 @@
#include <asm/processor.h>
#include <asm/sysreg.h>

-static bool mixed_endian_el0 = true;
unsigned long elf_hwcap __read_mostly;
EXPORT_SYMBOL_GPL(elf_hwcap);

@@ -44,22 +43,6 @@ unsigned int compat_elf_hwcap2 __read_mostly;

DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);

-
-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);
-}
-
#define ARM64_FTR_BITS(STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
{ \
.strict = STRICT, \
@@ -433,9 +416,6 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
-
- /* This will be removed later, once we start using the infrastructure */
- update_mixed_endian_el0_support(info);
}

static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
@@ -586,8 +566,6 @@ void update_cpu_features(int cpu,
*/
WARN_TAINT_ONCE(taint, TAINT_CPU_OUT_OF_SPEC,
"Unsupported CPU feature variation.\n");
-
- update_mixed_endian_el0_support(info);
}

u64 read_system_reg(u32 id)
--
1.7.9.5

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