Commit 1b59ddfc authored Sep 07, 2015 by John David Anglin Committed by Helge Deller Sep 08, 2015

parisc: Use double word condition in 64bit CAS operation



The attached change fixes the condition used in the "sub" instruction.
A double word comparison is needed.  This fixes the 64-bit LWS CAS
operation on 64-bit kernels.

I can now enable 64-bit atomic support in GCC.

Cc: <stable@vger.kernel.org>
Signed-off-by: John David Anglin <dave.anglin>
Signed-off-by: Helge Deller <deller@gmx.de>

parent b1b4e435

arch/parisc/kernel/syscall.S

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -821,7 +821,7 @@ cas2_action:
	/* 64bit CAS */		/* 64bit CAS */
	#ifdef CONFIG_64BIT		#ifdef CONFIG_64BIT
	19: ldd,ma 0(%sr3,%r26), %r29		19: ldd,ma 0(%sr3,%r26), %r29
	sub,= %r29, %r25, %r0		sub,*= %r29, %r25, %r0
	b,n cas2_end		b,n cas2_end
	20: std,ma %r24, 0(%sr3,%r26)		20: std,ma %r24, 0(%sr3,%r26)
	copy %r0, %r28		copy %r0, %r28