[3.8.y.z extended stable] Patch "ARM: mvebu: use the virtual CPU registers to access coherency" has been added to staging queue

[Kamal Mostafa]

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

    ARM: mvebu: use the virtual CPU registers to access coherency

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.15.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 5f1c1cbda929884ed99cfccc48998cce13dd1a24 Mon Sep 17 00:00:00 2001
From: Gregory CLEMENT <gregory.clement at free-electrons.com>
Date: Mon, 25 Nov 2013 17:26:46 +0100
Subject: ARM: mvebu: use the virtual CPU registers to access coherency
 registers

commit b6dda00cddcc71d2030668bc0cc0fed758c411c2 upstream.

The Armada XP provides a mechanism called "virtual CPU registers" or
"per-CPU register banking", to access the per-CPU registers of the
current CPU, without having to worry about finding on which CPU we're
running. CPU0 has its registers at 0x21800, CPU1 at 0x21900, CPU2 at
0x21A00 and CPU3 at 0x21B00. The virtual registers accessing the
current CPU registers are at 0x21000.

However, in the Device Tree node that provides the register addresses
for the coherency unit (which is responsible for ensuring coherency
between processors, and I/O coherency between processors and the
DMA-capable devices), a mistake was made: the CPU0-specific registers
were specified instead of the virtual CPU registers. This means that
the coherency barrier needed for I/O coherency was not behaving
properly when executed from a CPU different from CPU0. This patch
fixes that by using the virtual CPU registers.

Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Fixes: e60304f8cb7bb5 "arm: mvebu: Add hardware I/O Coherency support"
Signed-off-by: Jason Cooper <jason at lakedaemon.net>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/arm/boot/dts/armada-370-xp.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/armada-370-xp.dtsi b/arch/arm/boot/dts/armada-370-xp.dtsi
index 4c0abe8..269b6b0 100644
--- a/arch/arm/boot/dts/armada-370-xp.dtsi
+++ b/arch/arm/boot/dts/armada-370-xp.dtsi
@@ -39,7 +39,7 @@
 	coherency-fabric at d0020200 {
 		compatible = "marvell,coherency-fabric";
 		reg = <0xd0020200 0xb0>,
-		      <0xd0021810 0x1c>;
+		      <0xd0021010 0x1c>;
 	};

 	soc {
--
1.8.3.2