Commit fa8aa59a authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Factor out checking of a feature against the override into a macro 



Checking for a feature being supported from assembly code is
a bit tedious if we need to factor in the idreg override.

Since we already have such code written for forcing nVHE, move
the whole thing into a macro. This heavily relies on the override
structure being called foo_override for foo_el1.

No functional change.

Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220630160500.1536744-5-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent ae4b7e38

arch/arm64/kernel/hyp-stub.S

+20 −14
Original line number Diff line number Diff line
@@ -16,6 +16,25 @@ 
#include <asm/ptrace.h>

#include <asm/virt.h>



// Warning, hardcoded register allocation

// This will clobber x1 and x2.

.macro check_override idreg, fld, pass, fail

	mrs	x1, \idreg\()_el1

	ubfx	x1, x1, #\fld, #4

	cbz	x1, \fail



	adr_l	x1, \idreg\()_override

	ldr	x2, [x1, FTR_OVR_VAL_OFFSET]

	ldr	x1, [x1, FTR_OVR_MASK_OFFSET]

	ubfx	x2, x2, #\fld, #4

	ubfx	x1, x1, #\fld, #4

	cmp	x1, xzr

	and	x2, x2, x1

	csinv	x2, x2, xzr, ne

	cbnz	x2, \pass

	b	\fail

.endm



	.text

	.pushsection	.hyp.text, "ax"
@@ -80,20 +99,7 @@ SYM_CODE_START_LOCAL(__finalise_el2) 
	tbnz	x1, #0, 1f



	// Needs to be VHE capable, obviously

	mrs	x1, id_aa64mmfr1_el1

	ubfx	x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4

	cbz	x1, 1f



	// Check whether VHE is disabled from the command line

	adr_l	x1, id_aa64mmfr1_override

	ldr	x2, [x1, FTR_OVR_VAL_OFFSET]

	ldr	x1, [x1, FTR_OVR_MASK_OFFSET]

	ubfx	x2, x2, #ID_AA64MMFR1_VHE_SHIFT, #4

	ubfx	x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4

	cmp	x1, xzr

	and	x2, x2, x1

	csinv	x2, x2, xzr, ne

	cbnz	x2, 2f

	check_override id_aa64mmfr1 ID_AA64MMFR1_VHE_SHIFT 2f 1f



1:	mov_q	x0, HVC_STUB_ERR

	eret