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Commit 8e9c24a2 authored by Russell King's avatar Russell King Committed by Will Deacon
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ARM: virt: avoid clobbering lr when forcing svc mode 



The safe_svcmode_maskall macro is used to ensure that we are running in
svc mode, causing an exception return from hvc mode if required.

This patch removes the unneeded lr clobber from the macro and operates
entirely on the temporary parameter register instead.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
[will: updated comment]
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 9931faca

arch/arm/include/asm/assembler.h

+3 −7
Original line number Diff line number Diff line
@@ -246,18 +246,14 @@ 
 *

 * This macro is intended for forcing the CPU into SVC mode at boot time.

 * you cannot return to the original mode.

 *

 * Beware, it also clobers LR.

 */

.macro safe_svcmode_maskall reg:req

#if __LINUX_ARM_ARCH__ >= 6

	mrs	\reg , cpsr

	mov	lr , \reg

	and	lr , lr , #MODE_MASK

	cmp	lr , #HYP_MODE

	orr	\reg , \reg , #PSR_I_BIT | PSR_F_BIT

	eor	\reg, \reg, #HYP_MODE

	tst	\reg, #MODE_MASK

	bic	\reg , \reg , #MODE_MASK

	orr	\reg , \reg , #SVC_MODE

	orr	\reg , \reg , #PSR_I_BIT | PSR_F_BIT | SVC_MODE

THUMB(	orr	\reg , \reg , #PSR_T_BIT	)

	bne	1f

	orr	\reg, \reg, #PSR_A_BIT