Patch "parisc: Use double word condition in 64bit CAS operation" has been added to the 4.2-stable tree

Patch "parisc: Use double word condition in 64bit CAS operation" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    parisc: Use double word condition in 64bit CAS operation

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     parisc-use-double-word-condition-in-64bit-cas-operation.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 1b59ddfcf1678de38a1f8ca9fb8ea5eebeff1843 Mon Sep 17 00:00:00 2001
From: John David Anglin <dave.anglin@bell.net>
Date: Mon, 7 Sep 2015 20:13:28 -0400
Subject: parisc: Use double word condition in 64bit CAS operation

From: John David Anglin <dave.anglin@bell.net>

commit 1b59ddfcf1678de38a1f8ca9fb8ea5eebeff1843 upstream.

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.

Signed-off-by: John David Anglin <dave.anglin>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/parisc/kernel/syscall.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -821,7 +821,7 @@ cas2_action:
 	/* 64bit CAS */
 #ifdef CONFIG_64BIT
 19:	ldd,ma	0(%sr3,%r26), %r29
-	sub,=	%r29, %r25, %r0
+	sub,*=	%r29, %r25, %r0
 	b,n	cas2_end
 20:	std,ma	%r24, 0(%sr3,%r26)
 	copy	%r0, %r28


Patches currently in stable-queue which might be from dave.anglin@bell.net are

queue-4.2/parisc-use-double-word-condition-in-64bit-cas-operation.patch