Commit 18c9aa49 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Add an override for ID_AA64SMFR0_EL1.FA64 



Add a specific override for ID_AA64SMFR0_EL1.FA64, which
disables the full A64 streaming SVE mode.

Note that no alias is provided for this, as this is already
covered by arm64.nosme, and is only added as a debugging
facility.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220630160500.1536744-10-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 504ee236

arch/arm64/kernel/hyp-stub.S

+8 −7
Original line number Diff line number Diff line
@@ -122,17 +122,18 @@ SYM_CODE_START_LOCAL(__finalise_el2) 
	msr	sctlr_el2, x1

	isb



	mov	x1, #0				// SMCR controls

	mov	x0, #0				// SMCR controls



	mrs_s	x2, SYS_ID_AA64SMFR0_EL1

	ubfx	x2, x2, #ID_AA64SMFR0_FA64_SHIFT, #1 // Full FP in SM?

	cbz	x2, .Lskip_sme_fa64

	// Full FP in SM?

	mrs_s	x1, SYS_ID_AA64SMFR0_EL1

	__check_override id_aa64smfr0 ID_AA64SMFR0_FA64_SHIFT 1 .Linit_sme_fa64 .Lskip_sme_fa64



	orr	x1, x1, SMCR_ELx_FA64_MASK

.Linit_sme_fa64:

	orr	x0, x0, SMCR_ELx_FA64_MASK

.Lskip_sme_fa64:



	orr	x1, x1, #SMCR_ELx_LEN_MASK	// Enable full SME vector

	msr_s	SYS_SMCR_EL2, x1		// length for EL1.

	orr	x0, x0, #SMCR_ELx_LEN_MASK	// Enable full SME vector

	msr_s	SYS_SMCR_EL2, x0		// length for EL1.



	mrs_s	x1, SYS_SMIDR_EL1		// Priority mapping supported?

	ubfx    x1, x1, #SMIDR_EL1_SMPS_SHIFT, #1

arch/arm64/kernel/idreg-override.c

+11 −0
Original line number Diff line number Diff line
@@ -127,6 +127,16 @@ static const struct ftr_set_desc isar2 __initconst = { 
	},

};



static const struct ftr_set_desc smfr0 __initconst = {

	.name		= "id_aa64smfr0",

	.override	= &id_aa64smfr0_override,

	.fields		= {

		/* FA64 is a one bit field... :-/ */

	        { "fa64", ID_AA64SMFR0_FA64_SHIFT, 1, },

		{}

	},

};



extern struct arm64_ftr_override kaslr_feature_override;



static const struct ftr_set_desc kaslr __initconst = {
@@ -146,6 +156,7 @@ static const struct ftr_set_desc * const regs[] __initconst = { 
	&pfr1,

	&isar1,

	&isar2,

	&smfr0,

	&kaslr,

};