[3.16.y-ckt stable] Patch "parisc: Use double word condition in 64bit CAS operation" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Mon Sep 28 17:31:05 UTC 2015


This is a note to let you know that I have just added a patch titled

    parisc: Use double word condition in 64bit CAS operation

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt18.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 1ed7d6ff5f68adaf4bfcbfe745bec67de66ade90 Mon Sep 17 00:00:00 2001
From: John David Anglin <dave.anglin at bell.net>
Date: Mon, 7 Sep 2015 20:13:28 -0400
Subject: parisc: Use double word condition in 64bit CAS operation

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 at gmx.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/parisc/kernel/syscall.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 7ef22e3387e0..0b8d26d3ba43 100644
--- 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




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