X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-ia64%2Fmmu_context.h;h=b5c65081a3aab49bc051b7209c03d0ca54122160;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=0096e7e05012705baecbeaf4cbe654b76bbed767;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h index 0096e7e05..b5c65081a 100644 --- a/include/asm-ia64/mmu_context.h +++ b/include/asm-ia64/mmu_context.h @@ -7,18 +7,20 @@ */ /* - * Routines to manage the allocation of task context numbers. Task context numbers are - * used to reduce or eliminate the need to perform TLB flushes due to context switches. - * Context numbers are implemented using ia-64 region ids. Since the IA-64 TLB does not - * consider the region number when performing a TLB lookup, we need to assign a unique - * region id to each region in a process. We use the least significant three bits in a - * region id for this purpose. + * Routines to manage the allocation of task context numbers. Task context + * numbers are used to reduce or eliminate the need to perform TLB flushes + * due to context switches. Context numbers are implemented using ia-64 + * region ids. Since the IA-64 TLB does not consider the region number when + * performing a TLB lookup, we need to assign a unique region id to each + * region in a process. We use the least significant three bits in aregion + * id for this purpose. */ #define IA64_REGION_ID_KERNEL 0 /* the kernel's region id (tlb.c depends on this being 0) */ #define ia64_rid(ctx,addr) (((ctx) << 3) | (addr >> 61)) +# include # ifndef __ASSEMBLY__ #include @@ -31,13 +33,17 @@ struct ia64_ctx { spinlock_t lock; unsigned int next; /* next context number to use */ - unsigned int limit; /* next >= limit => must call wrap_mmu_context() */ - unsigned int max_ctx; /* max. context value supported by all CPUs */ + unsigned int limit; /* available free range */ + unsigned int max_ctx; /* max. context value supported by all CPUs */ + /* call wrap_mmu_context when next >= max */ + unsigned long *bitmap; /* bitmap size is max_ctx+1 */ + unsigned long *flushmap;/* pending rid to be flushed */ }; extern struct ia64_ctx ia64_ctx; DECLARE_PER_CPU(u8, ia64_need_tlb_flush); +extern void mmu_context_init (void); extern void wrap_mmu_context (struct mm_struct *mm); static inline void @@ -46,49 +52,66 @@ enter_lazy_tlb (struct mm_struct *mm, struct task_struct *tsk) } /* - * When the context counter wraps around all TLBs need to be flushed because an old - * context number might have been reused. This is signalled by the ia64_need_tlb_flush - * per-CPU variable, which is checked in the routine below. Called by activate_mm(). - * + * When the context counter wraps around all TLBs need to be flushed because + * an old context number might have been reused. This is signalled by the + * ia64_need_tlb_flush per-CPU variable, which is checked in the routine + * below. Called by activate_mm(). */ static inline void delayed_tlb_flush (void) { extern void local_flush_tlb_all (void); + unsigned long flags; if (unlikely(__ia64_per_cpu_var(ia64_need_tlb_flush))) { - local_flush_tlb_all(); - __ia64_per_cpu_var(ia64_need_tlb_flush) = 0; + spin_lock_irqsave(&ia64_ctx.lock, flags); + if (__ia64_per_cpu_var(ia64_need_tlb_flush)) { + local_flush_tlb_all(); + __ia64_per_cpu_var(ia64_need_tlb_flush) = 0; + } + spin_unlock_irqrestore(&ia64_ctx.lock, flags); } } -static inline mm_context_t +static inline nv_mm_context_t get_mmu_context (struct mm_struct *mm) { unsigned long flags; - mm_context_t context = mm->context; + nv_mm_context_t context = mm->context; - if (context) - return context; + if (likely(context)) + goto out; spin_lock_irqsave(&ia64_ctx.lock, flags); - { - /* re-check, now that we've got the lock: */ - context = mm->context; - if (context == 0) { - cpus_clear(mm->cpu_vm_mask); - if (ia64_ctx.next >= ia64_ctx.limit) + /* re-check, now that we've got the lock: */ + context = mm->context; + if (context == 0) { + cpus_clear(mm->cpu_vm_mask); + if (ia64_ctx.next >= ia64_ctx.limit) { + ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + if (ia64_ctx.next >= ia64_ctx.max_ctx) wrap_mmu_context(mm); - mm->context = context = ia64_ctx.next++; } + mm->context = context = ia64_ctx.next++; + __set_bit(context, ia64_ctx.bitmap); } spin_unlock_irqrestore(&ia64_ctx.lock, flags); +out: + /* + * Ensure we're not starting to use "context" before any old + * uses of it are gone from our TLB. + */ + delayed_tlb_flush(); + return context; } /* - * Initialize context number to some sane value. MM is guaranteed to be a brand-new - * address-space, so no TLB flushing is needed, ever. + * Initialize context number to some sane value. MM is guaranteed to be a + * brand-new address-space, so no TLB flushing is needed, ever. */ static inline int init_new_context (struct task_struct *p, struct mm_struct *mm) @@ -104,13 +127,13 @@ destroy_context (struct mm_struct *mm) } static inline void -reload_context (mm_context_t context) +reload_context (nv_mm_context_t context) { unsigned long rid; unsigned long rid_incr = 0; unsigned long rr0, rr1, rr2, rr3, rr4, old_rr4; - old_rr4 = ia64_get_rr(0x8000000000000000UL); + old_rr4 = ia64_get_rr(RGN_BASE(RGN_HPAGE)); rid = context << 3; /* make space for encoding the region number */ rid_incr = 1 << 8; @@ -122,6 +145,10 @@ reload_context (mm_context_t context) rr4 = rr0 + 4*rid_incr; #ifdef CONFIG_HUGETLB_PAGE rr4 = (rr4 & (~(0xfcUL))) | (old_rr4 & 0xfc); + +# if RGN_HPAGE != 4 +# error "reload_context assumes RGN_HPAGE is 4" +# endif #endif ia64_set_rr(0x0000000000000000UL, rr0); @@ -132,17 +159,23 @@ reload_context (mm_context_t context) ia64_srlz_i(); /* srlz.i implies srlz.d */ } +/* + * Must be called with preemption off + */ static inline void activate_context (struct mm_struct *mm) { - mm_context_t context; + nv_mm_context_t context; do { context = get_mmu_context(mm); if (!cpu_isset(smp_processor_id(), mm->cpu_vm_mask)) cpu_set(smp_processor_id(), mm->cpu_vm_mask); reload_context(context); - /* in the unlikely event of a TLB-flush by another thread, redo the load: */ + /* + * in the unlikely event of a TLB-flush by another thread, + * redo the load. + */ } while (unlikely(context != mm->context)); } @@ -154,11 +187,9 @@ activate_context (struct mm_struct *mm) static inline void activate_mm (struct mm_struct *prev, struct mm_struct *next) { - delayed_tlb_flush(); - /* - * We may get interrupts here, but that's OK because interrupt handlers cannot - * touch user-space. + * We may get interrupts here, but that's OK because interrupt + * handlers cannot touch user-space. */ ia64_set_kr(IA64_KR_PT_BASE, __pa(next->pgd)); activate_context(next);