From 82622284dd2f8791f9759f3cef601520a8bc63b2 Mon Sep 17 00:00:00 2001 From: David Daney Date: Wed, 14 Oct 2009 12:16:56 -0700 Subject: 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 Signed-off-by: Ralf Baechle --- arch/mips/include/asm/mmu_context.h | 29 ++++++++++++++++++++++++++++- arch/mips/include/asm/stackframe.h | 20 ++++++++++---------- 2 files changed, 38 insertions(+), 11 deletions(-) (limited to 'arch/mips/include/asm') diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index 6083db5..145bb81 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -24,6 +24,33 @@ #endif /* SMTC */ #include +#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 diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h index dd7e220..3b6da33 100644 --- a/arch/mips/include/asm/stackframe.h +++ b/arch/mips/include/asm/stackframe.h @@ -87,15 +87,19 @@ #ifdef CONFIG_SMP #ifdef CONFIG_MIPS_MT_SMTC #define PTEBASE_SHIFT 19 /* TCBIND */ +#define CPU_ID_REG CP0_TCBIND +#define CPU_ID_MFC0 mfc0 +#elif defined(CONFIG_MIPS_PGD_C0_CONTEXT) +#define PTEBASE_SHIFT 48 /* XCONTEXT */ +#define CPU_ID_REG CP0_XCONTEXT +#define CPU_ID_MFC0 MFC0 #else #define PTEBASE_SHIFT 23 /* CONTEXT */ +#define CPU_ID_REG CP0_CONTEXT +#define CPU_ID_MFC0 MFC0 #endif .macro get_saved_sp /* SMP variation */ -#ifdef CONFIG_MIPS_MT_SMTC - mfc0 k0, CP0_TCBIND -#else - MFC0 k0, CP0_CONTEXT -#endif + CPU_ID_MFC0 k0, CPU_ID_REG #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32) lui k1, %hi(kernelsp) #else @@ -111,11 +115,7 @@ .endm .macro set_saved_sp stackp temp temp2 -#ifdef CONFIG_MIPS_MT_SMTC - mfc0 \temp, CP0_TCBIND -#else - MFC0 \temp, CP0_CONTEXT -#endif + CPU_ID_MFC0 \temp, CPU_ID_REG LONG_SRL \temp, PTEBASE_SHIFT LONG_S \stackp, kernelsp(\temp) .endm -- cgit v1.1