Patch "ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7" has been added to the 4.4-stable tree
Subsystems (2)
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 <[email protected]> know about it.
Quoted 1 line
From
117e5e9c4cfcb7628f08de074fbfefec1bb678b7Mon Sep 17 00:00:00 2001
From: Srinivas Ramana <[email protected]>
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 <[email protected]>
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.
--- arch/arm/boot/compressed/head.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/arm/boot/compressed/head.S +1 -1
@@ -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 [email protected] are
queue-4.4/arm-8618-1-decompressor-reset-ttbcr-fields-to-use-ttbr0-on-armv7.patch