From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: <linuxppc-dev@ozlabs.org>
Subject: [PATCH] powerpc: Fix bogus cache flushing on all 40x and BookE processors v2
Date: Thu, 04 Dec 2008 17:12:59 +1100 [thread overview]
Message-ID: <20081204061341.C45CBDDDF6@ozlabs.org> (raw)
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 <benh@kernel.crashing.org>
---
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 */
next reply other threads:[~2008-12-04 6:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-04 6:12 Benjamin Herrenschmidt [this message]
2008-12-04 12:33 ` [PATCH] powerpc: Fix bogus cache flushing on all 40x and BookE processors v2 Josh Boyer
2008-12-04 22:02 ` Benjamin Herrenschmidt
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