From 6e4662ff49c6b94e16a47bfddb920576963b5a20 Mon Sep 17 00:00:00 2001 From: Stuart Menefy Date: Tue, 21 Nov 2006 13:53:44 +0900 Subject: [PATCH] sh: Use MMU.TTB register as pointer to current pgd. Add TTB accessor functions and give it a sensible default value. We will use this later for optimizing the fault path. Signed-off-by: Stuart Menefy Signed-off-by: Paul Mundt --- arch/sh/mm/init.c | 18 +++++++-------- include/asm-sh/mmu_context.h | 44 +++++++++++++++++++----------------- 2 files changed, 31 insertions(+), 31 deletions(-) diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index 8b275166f4..8c8d391183 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -155,9 +155,6 @@ extern char __init_begin, __init_end; /* * paging_init() sets up the page tables - * - * This routines also unmaps the page at virtual kernel address 0, so - * that we can trap those pesky NULL-reference errors in the kernel. */ void __init paging_init(void) { @@ -180,14 +177,11 @@ void __init paging_init(void) */ { unsigned long max_dma, low, start_pfn; - pgd_t *pg_dir; - int i; - - /* We don't need kernel mapping as hardware support that. */ - pg_dir = swapper_pg_dir; - for (i = 0; i < PTRS_PER_PGD; i++) - pgd_val(pg_dir[i]) = 0; + /* We don't need to map the kernel through the TLB, as + * it is permanatly mapped using P1. So clear the + * entire pgd. */ + memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); /* Turn on the MMU */ enable_mmu(); @@ -206,6 +200,10 @@ void __init paging_init(void) } } + /* Set an initial value for the MMU.TTB so we don't have to + * check for a null value. */ + set_TTB(swapper_pg_dir); + #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) /* * If we don't have CONFIG_MMU set and the processor in question diff --git a/include/asm-sh/mmu_context.h b/include/asm-sh/mmu_context.h index c7088efe57..46f04e23bd 100644 --- a/include/asm-sh/mmu_context.h +++ b/include/asm-sh/mmu_context.h @@ -10,7 +10,6 @@ #include #include -#include #include #include @@ -42,10 +41,8 @@ extern unsigned long mmu_context_cache; /* * Get MMU context if needed. */ -static __inline__ void -get_mmu_context(struct mm_struct *mm) +static inline void get_mmu_context(struct mm_struct *mm) { - extern void flush_tlb_all(void); unsigned long mc = mmu_context_cache; /* Check if we have old version of context. */ @@ -61,6 +58,7 @@ get_mmu_context(struct mm_struct *mm) * Flush all TLB and start new cycle. */ flush_tlb_all(); + /* * Fix version; Note that we avoid version #0 * to distingush NO_CONTEXT. @@ -75,11 +73,10 @@ get_mmu_context(struct mm_struct *mm) * Initialize the context related info for a new mm_struct * instance. */ -static __inline__ int init_new_context(struct task_struct *tsk, +static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { mm->context.id = NO_CONTEXT; - return 0; } @@ -87,12 +84,12 @@ static __inline__ int init_new_context(struct task_struct *tsk, * Destroy context related info for an mm_struct that is about * to be put to rest. */ -static __inline__ void destroy_context(struct mm_struct *mm) +static inline void destroy_context(struct mm_struct *mm) { /* Do nothing */ } -static __inline__ void set_asid(unsigned long asid) +static inline void set_asid(unsigned long asid) { unsigned long __dummy; @@ -105,7 +102,7 @@ static __inline__ void set_asid(unsigned long asid) "r" (0xffffff00)); } -static __inline__ unsigned long get_asid(void) +static inline unsigned long get_asid(void) { unsigned long asid; @@ -120,24 +117,29 @@ static __inline__ unsigned long get_asid(void) * After we have set current->mm to a new value, this activates * the context for the new mm so we see the new mappings. */ -static __inline__ void activate_context(struct mm_struct *mm) +static inline void activate_context(struct mm_struct *mm) { get_mmu_context(mm); set_asid(mm->context.id & MMU_CONTEXT_ASID_MASK); } -/* MMU_TTB can be used for optimizing the fault handling. - (Currently not used) */ -static __inline__ void switch_mm(struct mm_struct *prev, - struct mm_struct *next, - struct task_struct *tsk) +/* MMU_TTB is used for optimizing the fault handling. */ +static inline void set_TTB(pgd_t *pgd) { - if (likely(prev != next)) { - unsigned long __pgdir = (unsigned long)next->pgd; + ctrl_outl((unsigned long)pgd, MMU_TTB); +} - __asm__ __volatile__("mov.l %0, %1" - : /* no output */ - : "r" (__pgdir), "m" (__m(MMU_TTB))); +static inline pgd_t *get_TTB(void) +{ + return (pgd_t *)ctrl_inl(MMU_TTB); +} + +static inline void switch_mm(struct mm_struct *prev, + struct mm_struct *next, + struct task_struct *tsk) +{ + if (likely(prev != next)) { + set_TTB(next->pgd); activate_context(next); } } @@ -147,7 +149,7 @@ static __inline__ void switch_mm(struct mm_struct *prev, #define activate_mm(prev, next) \ switch_mm((prev),(next),NULL) -static __inline__ void +static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) { } -- 2.39.5