Patch "ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7" has been added to the 4.4-stable tree

Patch "ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7" has been added to the 4.4-stable tree

[gregkh]

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

    ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7

to the 4.4-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:
     arm-8618-1-decompressor-reset-ttbcr-fields-to-use-ttbr0-on-armv7.patch
and it can be found in the queue-4.4 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 117e5e9c4cfcb7628f08de074fbfefec1bb678b7 Mon Sep 17 00:00:00 2001
From: Srinivas Ramana <sramana@codeaurora.org>
Date: Fri, 30 Sep 2016 15:03:31 +0100
Subject: ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7

From: Srinivas Ramana <sramana@codeaurora.org>

commit 117e5e9c4cfcb7628f08de074fbfefec1bb678b7 upstream.

If the bootloader uses the long descriptor format and jumps to
kernel decompressor code, TTBCR may not be in a right state.
Before enabling the MMU, it is required to clear the TTBCR.PD0
field to use TTBR0 for translation table walks.

The commit dbece45894d3a ("ARM: 7501/1: decompressor:
reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but
doesn't consider all the bits for the size of TTBCR.N.

Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to
indicate the use of TTBR0 and the correct base address width.

Fixes: dbece45894d3 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm/boot/compressed/head.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -776,7 +776,7 @@ __armv7_mmu_cache_on:
 		orrne	r0, r0, #1		@ MMU enabled
 		movne	r1, #0xfffffffd		@ domain 0 = client
 		bic     r6, r6, #1 << 31        @ 32-bit translation system
-		bic     r6, r6, #3 << 0         @ use only ttbr0
+		bic     r6, r6, #(7 << 0) | (1 << 4)	@ use only ttbr0
 		mcrne	p15, 0, r3, c2, c0, 0	@ load page table pointer
 		mcrne	p15, 0, r1, c3, c0, 0	@ load domain access control
 		mcrne   p15, 0, r6, c2, c0, 2   @ load ttb control


Patches currently in stable-queue which might be from sramana@codeaurora.org are

queue-4.4/arm-8618-1-decompressor-reset-ttbcr-fields-to-use-ttbr0-on-armv7.patch