X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=include%2Fasm-ia64%2Fmmu_context.h;h=cef2400983fafe3fd1961895a4d355f11a14d34b;hb=4ec161cf73bc0b4e5c36843638ef9171896fc0b9;hp=0680d163be9733ee6fd45522d6e9dcf61de228d9;hpb=95ecc5e5a3b20a3c76164d089c69051662e9d9b3;p=linux-2.6-omap-h63xx.git diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h index 0680d163be9..cef2400983f 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 @@ -27,17 +29,22 @@ #include #include +#include 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 @@ -46,10 +53,10 @@ 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) @@ -59,11 +66,9 @@ delayed_tlb_flush (void) if (unlikely(__ia64_per_cpu_var(ia64_need_tlb_flush))) { 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; - } + 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); } @@ -75,20 +80,27 @@ get_mmu_context (struct mm_struct *mm) unsigned long flags; nv_mm_context_t context = mm->context; - if (unlikely(!context)) { - 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) - wrap_mmu_context(mm); - mm->context = context = ia64_ctx.next++; - } + 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) { + 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); } - spin_unlock_irqrestore(&ia64_ctx.lock, flags); + 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. @@ -99,8 +111,8 @@ get_mmu_context (struct mm_struct *mm) } /* - * 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) @@ -122,7 +134,7 @@ reload_context (nv_mm_context_t context) 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; @@ -134,6 +146,10 @@ reload_context (nv_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); @@ -157,7 +173,10 @@ activate_context (struct mm_struct *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)); } @@ -170,8 +189,8 @@ static inline void activate_mm (struct mm_struct *prev, struct mm_struct *next) { /* - * 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);