From 117e5e9c4cfcb7628f08de074fbfefec1bb678b7 Mon Sep 17 00:00:00 2001 From: Srinivas Ramana Date: Fri, 30 Sep 2016 15:03:31 +0100 Subject: [PATCH] ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7 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 Signed-off-by: Srinivas Ramana Signed-off-by: Russell King --- arch/arm/boot/compressed/head.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index af11c2f..fc6d541 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -779,7 +779,7 @@ __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 -- 2.7.4