Commit 04597a65 authored by Suzuki K. Poulose's avatar Suzuki K. Poulose Committed by Catalin Marinas
Browse files

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: default avatarSuzuki K. Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 78d51e0b

arch/arm64/include/asm/cpufeature.h

+2 −0
Original line number Diff line number Diff line
@@ -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__ */

arch/arm64/include/asm/cputype.h

+14 −0
Original line number Diff line number Diff line
@@ -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

arch/arm64/kernel/cpuinfo.c

+22 −0
Original line number Diff line number Diff line
@@ -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)

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