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authorDavid Daney <ddaney@caviumnetworks.com>2009-10-14 23:16:56 +0400
committerRalf Baechle <ralf@linux-mips.org>2009-12-17 04:57:01 +0300
commit82622284dd2f8791f9759f3cef601520a8bc63b2 (patch)
treeee47f43af373d0c021cc83ff9e22925942e9d001 /arch/mips/include/asm/mmu_context.h
parent92078e0618f525e22945040b5daea21d4b6d4a16 (diff)
downloadlinux-82622284dd2f8791f9759f3cef601520a8bc63b2.tar.xz
MIPS: Put PGD in C0_CONTEXT for 64-bit R2 processors.
Processors that support the mips64r2 ISA can in four instructions convert a shifted PGD pointer stored in the upper bits of c0_context into a usable pointer. By doing this we save a memory load and associated potential cache miss in the TLB exception handlers. Since the upper bits of c0_context were holding the CPU number, we move this to the upper bits of c0_xcontext which doesn't have enough bits to hold the PGD pointer, but has plenty for the CPU number. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/include/asm/mmu_context.h')
-rw-r--r--arch/mips/include/asm/mmu_context.h29
1 files changed, 28 insertions, 1 deletions
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index 6083db586500..145bb81ccaa5 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -24,6 +24,33 @@
#endif /* SMTC */
#include <asm-generic/mm_hooks.h>
+#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
+
+#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
+ tlbmiss_handler_setup_pgd((unsigned long)(pgd))
+
+static inline void tlbmiss_handler_setup_pgd(unsigned long pgd)
+{
+ /* Check for swapper_pg_dir and convert to physical address. */
+ if ((pgd & CKSEG3) == CKSEG0)
+ pgd = CPHYSADDR(pgd);
+ write_c0_context(pgd << 11);
+}
+
+#define TLBMISS_HANDLER_SETUP() \
+ do { \
+ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir); \
+ write_c0_xcontext((unsigned long) smp_processor_id() << 51); \
+ } while (0)
+
+
+static inline unsigned long get_current_pgd(void)
+{
+ return PHYS_TO_XKSEG_CACHED((read_c0_context() >> 11) & ~0xfffUL);
+}
+
+#else /* CONFIG_MIPS_PGD_C0_CONTEXT: using pgd_current*/
+
/*
* For the fast tlb miss handlers, we keep a per cpu array of pointers
* to the current pgd for each processor. Also, the proc. id is stuffed
@@ -46,7 +73,7 @@ extern unsigned long pgd_current[];
back_to_back_c0_hazard(); \
TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
#endif
-
+#endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
#define ASID_INC 0x40