Commit f6203722 authored by Yeoreum Yun's avatar Yeoreum Yun Committed by Catalin Marinas
Browse files

arm64/hwcaps: Add MTE_STORE_ONLY hwcaps 



Since ARMv8.9, FEAT_MTE_STORE_ONLY can be used to restrict raise of tag
check fault on store operation only.

add MTE_STORE_ONLY hwcaps so that user can use this feature.

Signed-off-by: default avatarYeoreum Yun <yeoreum.yun@arm.com>
Link: https://lore.kernel.org/r/20250618092957.2069907-5-yeoreum.yun@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 4d51ff5b

Documentation/arch/arm64/elf_hwcaps.rst

+3 −0
Original line number Diff line number Diff line
@@ -438,6 +438,9 @@ HWCAP2_POE 
HWCAP3_MTE_FAR

    Functionality implied by ID_AA64PFR2_EL1.MTEFAR == 0b0001.



HWCAP3_MTE_STORE_ONLY

    Functionality implied by ID_AA64PFR2_EL1.MTESTOREONLY == 0b0001.



4. Unused AT_HWCAP bits

-----------------------

arch/arm64/include/asm/hwcap.h

+1 −0
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@@ -177,6 +177,7 @@ 


#define __khwcap3_feature(x)		(const_ilog2(HWCAP3_ ## x) + 128)

#define KERNEL_HWCAP_MTE_FAR		__khwcap3_feature(MTE_FAR)

#define KERNEL_HWCAP_MTE_STORE_ONLY	__khwcap3_feature(MTE_STORE_ONLY)



/*

 * This yields a mask that user programs can use to figure out what

arch/arm64/include/uapi/asm/hwcap.h

+1 −0
Original line number Diff line number Diff line
@@ -144,5 +144,6 @@ 
 * HWCAP3 flags - for AT_HWCAP3

 */

#define HWCAP3_MTE_FAR		(1UL << 0)

#define HWCAP3_MTE_STORE_ONLY		(1UL << 1)



#endif /* _UAPI__ASM_HWCAP_H */

arch/arm64/kernel/cpufeature.c

+1 −0
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@@ -3228,6 +3228,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { 
	HWCAP_CAP(ID_AA64PFR1_EL1, MTE, MTE2, CAP_HWCAP, KERNEL_HWCAP_MTE),

	HWCAP_CAP(ID_AA64PFR1_EL1, MTE, MTE3, CAP_HWCAP, KERNEL_HWCAP_MTE3),

	HWCAP_CAP(ID_AA64PFR2_EL1, MTEFAR, IMP, CAP_HWCAP, KERNEL_HWCAP_MTE_FAR),

	HWCAP_CAP(ID_AA64PFR2_EL1, MTESTOREONLY, IMP, CAP_HWCAP , KERNEL_HWCAP_MTE_STORE_ONLY),

#endif /* CONFIG_ARM64_MTE */

	HWCAP_CAP(ID_AA64MMFR0_EL1, ECV, IMP, CAP_HWCAP, KERNEL_HWCAP_ECV),

	HWCAP_CAP(ID_AA64MMFR1_EL1, AFP, IMP, CAP_HWCAP, KERNEL_HWCAP_AFP),

arch/arm64/kernel/cpuinfo.c

+1 −0
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@@ -161,6 +161,7 @@ static const char *const hwcap_str[] = { 
	[KERNEL_HWCAP_SME_STMOP]	= "smestmop",

	[KERNEL_HWCAP_SME_SMOP4]	= "smesmop4",

	[KERNEL_HWCAP_MTE_FAR]		= "mtefar",

	[KERNEL_HWCAP_MTE_STORE_ONLY]	= "mtestoreonly",

};



#ifdef CONFIG_COMPAT