lkml.org 
[lkml]   [2016]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.7 051/141] ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7
    Date
    4.7-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    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
    @@ -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

    \
     
     \ /
      Last update: 2016-10-06 11:47    [W:4.165 / U:0.084 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site