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Commit 94a9e04a authored by Marc Zyngier's avatar Marc Zyngier Committed by Catalin Marinas
Browse files

arm64: alternative: Introduce feature for GICv3 CPU interface 



Add a new item to the feature set (ARM64_HAS_SYSREG_GIC_CPUIF)
to indicate that we have a system register GIC CPU interface

This will help KVM switching to alternative instruction patching.

Reviewed-by: default avatarAndre Przywara <andre.przywara@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 73bf8412

arch/arm64/include/asm/cpufeature.h

+7 −1
Original line number Original line Diff line number Diff line
@@ -24,8 +24,9 @@ 
#define ARM64_WORKAROUND_CLEAN_CACHE		0

#define ARM64_WORKAROUND_CLEAN_CACHE		0

#define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE	1

#define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE	1

#define ARM64_WORKAROUND_845719			2

#define ARM64_WORKAROUND_845719			2

#define ARM64_HAS_SYSREG_GIC_CPUIF		3





#define ARM64_NCAPS				3

#define ARM64_NCAPS				4





#ifndef __ASSEMBLY__

#ifndef __ASSEMBLY__
@@ -38,6 +39,11 @@ struct arm64_cpu_capabilities { 
			u32 midr_model;

			u32 midr_model;

			u32 midr_range_min, midr_range_max;

			u32 midr_range_min, midr_range_max;

		};

		};



		struct {	/* Feature register checking */

			u64 register_mask;

			u64 register_value;

		};

	};

	};

};

};

arch/arm64/kernel/cpufeature.c

+16 −0
Original line number Original line Diff line number Diff line
@@ -22,7 +22,23 @@ 
#include <asm/cpu.h>

#include <asm/cpu.h>

#include <asm/cpufeature.h>

#include <asm/cpufeature.h>





static bool

has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry)

{

	u64 val;



	val = read_cpuid(id_aa64pfr0_el1);

	return (val & entry->register_mask) == entry->register_value;

}



static const struct arm64_cpu_capabilities arm64_features[] = {

static const struct arm64_cpu_capabilities arm64_features[] = {

	{

		.desc = "GIC system register CPU interface",

		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,

		.matches = has_id_aa64pfr0_feature,

		.register_mask = (0xf << 24),

		.register_value = (1 << 24),

	},

	{},

	{},

};

};