recipes/linux/linux-omap-2.6.37/linus/0057-ARM-pxa-fix-page-table-corruption-on-resume.patch

   1 From 24c78557741395e038e83f25367cf2bfd7f582b8 Mon Sep 17 00:00:00 2001
   2 From: Aric D. Blumer <aric@sdgsystems.com>
   3 Date: Wed, 29 Dec 2010 11:18:29 -0500
   4 Subject: [PATCH 57/66] ARM: pxa: fix page table corruption on resume
   5
   6 Before this patch, the following error would sometimes occur after a
   7 resume on pxa3xx:
   8
   9     /path/to/mm/memory.c:144: bad pmd 8040542e.
  10
  11 The problem was that a temporary page table mapping was being improperly
  12 restored.
  13
  14 The PXA3xx resume code creates a temporary mapping of resume_turn_on_mmu
  15 to avoid a prefetch abort.  The pxa3xx_resume_after_mmu code requires
  16 that the r1 register holding the address of this mapping not be
  17 modified, however, resume_turn_on_mmu does modify it. It is mostly
  18 correct in that r1 receives the base table address, but it may also
  19 get other bits in 13:0.  This results in pxa3xx_resume_after_mmu
  20 restoring the original mapping to the wrong place, corrupting memory
  21 and leaving the temporary mapping in place.
  22
  23 Signed-off-by: Matt Reimer <mreimer@sdgsystems.com>
  24 Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
  25 ---
  26  arch/arm/mach-pxa/sleep.S |    4 ++--
  27  1 files changed, 2 insertions(+), 2 deletions(-)
  28
  29 diff --git a/arch/arm/mach-pxa/sleep.S b/arch/arm/mach-pxa/sleep.S
  30 index 52c30b0..ae00811 100644
  31 --- a/arch/arm/mach-pxa/sleep.S
  32 +++ b/arch/arm/mach-pxa/sleep.S
  33 @@ -353,8 +353,8 @@ resume_turn_on_mmu:
  34
  35         @ Let us ensure we jump to resume_after_mmu only when the mcr above
  36         @ actually took effect.  They call it the "cpwait" operation.
  37 -       mrc     p15, 0, r1, c2, c0, 0           @ queue a dependency on CP15
  38 -       sub     pc, r2, r1, lsr #32             @ jump to virtual addr
  39 +       mrc     p15, 0, r0, c2, c0, 0           @ queue a dependency on CP15
  40 +       sub     pc, r2, r0, lsr #32             @ jump to virtual addr
  41         nop
  42         nop
  43         nop
  44 --
  45 1.6.6.1
  46