diff options
Diffstat (limited to 'arch/parisc/include/asm/tlbflush.h')
| -rw-r--r-- | arch/parisc/include/asm/tlbflush.h | 53 |
1 files changed, 29 insertions, 24 deletions
diff --git a/arch/parisc/include/asm/tlbflush.h b/arch/parisc/include/asm/tlbflush.h index 9d086a599fa0..e84b96478193 100644 --- a/arch/parisc/include/asm/tlbflush.h +++ b/arch/parisc/include/asm/tlbflush.h @@ -13,6 +13,9 @@ * active at any one time on the Merced bus. This tlb purge * synchronisation is fairly lightweight and harmless so we activate * it on all systems not just the N class. + + * It is also used to ensure PTE updates are atomic and consistent + * with the TLB. */ extern spinlock_t pa_tlb_lock; @@ -24,20 +27,24 @@ extern void flush_tlb_all_local(void *); #define smp_flush_tlb_all() flush_tlb_all() +int __flush_tlb_range(unsigned long sid, + unsigned long start, unsigned long end); + +#define flush_tlb_range(vma, start, end) \ + __flush_tlb_range((vma)->vm_mm->context, start, end) + +#define flush_tlb_kernel_range(start, end) \ + __flush_tlb_range(0, start, end) + /* * flush_tlb_mm() * - * XXX This code is NOT valid for HP-UX compatibility processes, - * (although it will probably work 99% of the time). HP-UX - * processes are free to play with the space id's and save them - * over long periods of time, etc. so we have to preserve the - * space and just flush the entire tlb. We need to check the - * personality in order to do that, but the personality is not - * currently being set correctly. - * - * Of course, Linux processes could do the same thing, but - * we don't support that (and the compilers, dynamic linker, - * etc. do not do that). + * The code to switch to a new context is NOT valid for processes + * which play with the space id's. Thus, we have to preserve the + * space and just flush the entire tlb. However, the compilers, + * dynamic linker, etc, do not manipulate space id's, so there + * could be a significant performance benefit in switching contexts + * and not flushing the whole tlb. */ static inline void flush_tlb_mm(struct mm_struct *mm) @@ -45,10 +52,18 @@ static inline void flush_tlb_mm(struct mm_struct *mm) BUG_ON(mm == &init_mm); /* Should never happen */ #if 1 || defined(CONFIG_SMP) + /* Except for very small threads, flushing the whole TLB is + * faster than using __flush_tlb_range. The pdtlb and pitlb + * instructions are very slow because of the TLB broadcast. + * It might be faster to do local range flushes on all CPUs + * on PA 2.0 systems. + */ flush_tlb_all(); #else /* FIXME: currently broken, causing space id and protection ids - * to go out of sync, resulting in faults on userspace accesses. + * to go out of sync, resulting in faults on userspace accesses. + * This approach needs further investigation since running many + * small applications (e.g., GCC testsuite) is faster on HP-UX. */ if (mm) { if (mm->context != 0) @@ -65,22 +80,12 @@ static inline void flush_tlb_page(struct vm_area_struct *vma, { unsigned long flags, sid; - /* For one page, it's not worth testing the split_tlb variable */ - - mb(); sid = vma->vm_mm->context; purge_tlb_start(flags); mtsp(sid, 1); pdtlb(addr); - pitlb(addr); + if (unlikely(split_tlb)) + pitlb(addr); purge_tlb_end(flags); } - -void __flush_tlb_range(unsigned long sid, - unsigned long start, unsigned long end); - -#define flush_tlb_range(vma,start,end) __flush_tlb_range((vma)->vm_mm->context,start,end) - -#define flush_tlb_kernel_range(start, end) __flush_tlb_range(0,start,end) - #endif |