releases/3.5.1/powerpc-add-memory-attribute-for-mfmsr.patch

   1 From b416c9a10baae6a177b4f9ee858b8d309542fbef Mon Sep 17 00:00:00 2001
   2 From: Tiejun Chen <tiejun.chen@windriver.com>
   3 Date: Wed, 11 Jul 2012 14:22:46 +1000
   4 Subject: powerpc: Add "memory" attribute for mfmsr()
   5
   6 From: Tiejun Chen <tiejun.chen@windriver.com>
   7
   8 commit b416c9a10baae6a177b4f9ee858b8d309542fbef upstream.
   9
  10 Add "memory" attribute in inline assembly language as a compiler
  11 barrier to make sure 4.6.x GCC don't reorder mfmsr().
  12
  13 Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
  14 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
  15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  16
  17 ---
  18  arch/powerpc/include/asm/reg.h |    3 ++-
  19  1 file changed, 2 insertions(+), 1 deletion(-)
  20
  21 --- a/arch/powerpc/include/asm/reg.h
  22 +++ b/arch/powerpc/include/asm/reg.h
  23 @@ -1024,7 +1024,8 @@
  24  /* Macros for setting and retrieving special purpose registers */
  25  #ifndef __ASSEMBLY__
  26  #define mfmsr()                ({unsigned long rval; \
  27 -                       asm volatile("mfmsr %0" : "=r" (rval)); rval;})
  28 +                       asm volatile("mfmsr %0" : "=r" (rval) : \
  29 +                                               : "memory"); rval;})
  30  #ifdef CONFIG_PPC_BOOK3S_64
  31  #define __mtmsrd(v, l) asm volatile("mtmsrd %0," __stringify(l) \
  32                                      : : "r" (v) : "memory")