We were missing the CPU_FTR_NOEXECUTE bit in our cputable for all
these processors. The result is that update_mmu_cache() would flush
the cache for all pages mapped to userspace which is totally
unnecessary on those processors since we already handle flushing
on execute in the page fault path.

This should provide a nice speed up ;-)

Signed-off-by: Benjamin Herrenschmidt <[EMAIL PROTECTED]>
---

This one fixes the E500 definition and uses a bit that works
for 32-bit processors

 arch/powerpc/include/asm/cputable.h |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

--- linux-work.orig/arch/powerpc/include/asm/cputable.h 2008-12-01 
16:55:53.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/cputable.h      2008-12-04 
15:03:47.000000000 +1100
@@ -163,6 +163,7 @@ extern const char *powerpc_base_platform
 #define CPU_FTR_SPE                    ASM_CONST(0x0000000002000000)
 #define CPU_FTR_NEED_PAIRED_STWCX      ASM_CONST(0x0000000004000000)
 #define CPU_FTR_LWSYNC                 ASM_CONST(0x0000000008000000)
+#define CPU_FTR_NOEXECUTE              ASM_CONST(0x0000000010000000)
 
 /*
  * Add the 64-bit processor unique features in the top half of the word;
@@ -177,7 +178,6 @@ extern const char *powerpc_base_platform
 #define CPU_FTR_SLB                    LONG_ASM_CONST(0x0000000100000000)
 #define CPU_FTR_16M_PAGE               LONG_ASM_CONST(0x0000000200000000)
 #define CPU_FTR_TLBIEL                 LONG_ASM_CONST(0x0000000400000000)
-#define CPU_FTR_NOEXECUTE              LONG_ASM_CONST(0x0000000800000000)
 #define CPU_FTR_IABR                   LONG_ASM_CONST(0x0000002000000000)
 #define CPU_FTR_MMCRA                  LONG_ASM_CONST(0x0000004000000000)
 #define CPU_FTR_CTRL                   LONG_ASM_CONST(0x0000008000000000)
@@ -366,19 +366,20 @@ extern const char *powerpc_base_platform
 #define CPU_FTRS_CLASSIC32     (CPU_FTR_COMMON | \
            CPU_FTR_USE_TB | CPU_FTR_HPTE_TABLE)
 #define CPU_FTRS_8XX   (CPU_FTR_USE_TB)
-#define CPU_FTRS_40X   (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN)
-#define CPU_FTRS_44X   (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN)
+#define CPU_FTRS_40X   (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | 
CPU_FTR_NOEXECUTE)
+#define CPU_FTRS_44X   (CPU_FTR_USE_TB | CPU_FTR_NODSISRALIGN | 
CPU_FTR_NOEXECUTE)
 #define CPU_FTRS_E200  (CPU_FTR_USE_TB | CPU_FTR_SPE_COMP | \
            CPU_FTR_NODSISRALIGN | CPU_FTR_COHERENT_ICACHE | \
-           CPU_FTR_UNIFIED_ID_CACHE)
+           CPU_FTR_UNIFIED_ID_CACHE | CPU_FTR_NOEXECUTE)
 #define CPU_FTRS_E500  (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
-           CPU_FTR_SPE_COMP | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_NODSISRALIGN)
+           CPU_FTR_SPE_COMP | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_NODSISRALIGN | \
+           CPU_FTR_NOEXECUTE)
 #define CPU_FTRS_E500_2        (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
            CPU_FTR_SPE_COMP | CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_BIG_PHYS | \
-           CPU_FTR_NODSISRALIGN)
+           CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE)
 #define CPU_FTRS_E500MC        (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
            CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_BIG_PHYS | CPU_FTR_NODSISRALIGN | \
-           CPU_FTR_L2CSR | CPU_FTR_LWSYNC)
+           CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE)
 #define CPU_FTRS_GENERIC_32    (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
 
 /* 64-bit CPUs */
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