arch/parisc/include/asm/tlbflush.h

   1 #ifndef _PARISC_TLBFLUSH_H
   2 #define _PARISC_TLBFLUSH_H
   3
   4 /* TLB flushing routines.... */
   5
   6 #include <linux/mm.h>
   7 #include <linux/sched.h>
   8 #include <asm/mmu_context.h>
   9
  10
  11 /* This is for the serialisation of PxTLB broadcasts.  At least on the
  12  * N class systems, only one PxTLB inter processor broadcast can be
  13  * active at any one time on the Merced bus.  This tlb purge
  14  * synchronisation is fairly lightweight and harmless so we activate
  15  * it on all systems not just the N class.
  16
  17  * It is also used to ensure PTE updates are atomic and consistent
  18  * with the TLB.
  19  */
  20 extern spinlock_t pa_tlb_lock;
  21
  22 #define purge_tlb_start(flags)  spin_lock_irqsave(&pa_tlb_lock, flags)
  23 #define purge_tlb_end(flags)    spin_unlock_irqrestore(&pa_tlb_lock, flags)
  24
  25 extern void flush_tlb_all(void);
  26 extern void flush_tlb_all_local(void *);
  27
  28 #define smp_flush_tlb_all()     flush_tlb_all()
  29
  30 int __flush_tlb_range(unsigned long sid,
  31         unsigned long start, unsigned long end);
  32
  33 #define flush_tlb_range(vma, start, end) \
  34         __flush_tlb_range((vma)->vm_mm->context, start, end)
  35
  36 #define flush_tlb_kernel_range(start, end) \
  37         __flush_tlb_range(0, start, end)
  38
  39 /*
  40  * flush_tlb_mm()
  41  *
  42  * The code to switch to a new context is NOT valid for processes
  43  * which play with the space id's.  Thus, we have to preserve the
  44  * space and just flush the entire tlb.  However, the compilers,
  45  * dynamic linker, etc, do not manipulate space id's, so there
  46  * could be a significant performance benefit in switching contexts
  47  * and not flushing the whole tlb.
  48  */
  49
  50 static inline void flush_tlb_mm(struct mm_struct *mm)
  51 {
  52         BUG_ON(mm == &init_mm); /* Should never happen */
  53
  54 #if 1 || defined(CONFIG_SMP)
  55         /* Except for very small threads, flushing the whole TLB is
  56          * faster than using __flush_tlb_range.  The pdtlb and pitlb
  57          * instructions are very slow because of the TLB broadcast.
  58          * It might be faster to do local range flushes on all CPUs
  59          * on PA 2.0 systems.
  60          */
  61         flush_tlb_all();
  62 #else
  63         /* FIXME: currently broken, causing space id and protection ids
  64          * to go out of sync, resulting in faults on userspace accesses.
  65          * This approach needs further investigation since running many
  66          * small applications (e.g., GCC testsuite) is faster on HP-UX.
  67          */
  68         if (mm) {
  69                 if (mm->context != 0)
  70                         free_sid(mm->context);
  71                 mm->context = alloc_sid();
  72                 if (mm == current->active_mm)
  73                         load_context(mm->context);
  74         }
  75 #endif
  76 }
  77
  78 static inline void flush_tlb_page(struct vm_area_struct *vma,
  79         unsigned long addr)
  80 {
  81         unsigned long flags, sid;
  82
  83         sid = vma->vm_mm->context;
  84         purge_tlb_start(flags);
  85         mtsp(sid, 1);
  86         pdtlb(addr);
  87         if (unlikely(split_tlb))
  88                 pitlb(addr);
  89         purge_tlb_end(flags);
  90 }
  91 #endif