LXR linux/arch/xtensa/mm/tlb.c

   1/*
   2 * arch/xtensa/mm/tlb.c
   3 *
   4 * Logic that manipulates the Xtensa MMU.  Derived from MIPS.
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License.  See the file "COPYING" in the main directory of this archive
   8 * for more details.
   9 *
  10 * Copyright (C) 2001 - 2003 Tensilica Inc.
  11 *
  12 * Joe Taylor
  13 * Chris Zankel <chris@zankel.net>
  14 * Marc Gauthier
  15 */
  16
  17#include <linux/mm.h>
  18#include <asm/processor.h>
  19#include <asm/mmu_context.h>
  20#include <asm/tlbflush.h>
  21#include <asm/system.h>
  22#include <asm/cacheflush.h>
  23
  24
  25static inline void __flush_itlb_all (void)
  26{
  27        int w, i;
  28
  29        for (w = 0; w < ITLB_ARF_WAYS; w++) {
  30                for (i = 0; i < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); i++) {
  31                        int e = w + (i << PAGE_SHIFT);
  32                        invalidate_itlb_entry_no_isync(e);
  33                }
  34        }
  35        asm volatile ("isync\n");
  36}
  37
  38static inline void __flush_dtlb_all (void)
  39{
  40        int w, i;
  41
  42        for (w = 0; w < DTLB_ARF_WAYS; w++) {
  43                for (i = 0; i < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); i++) {
  44                        int e = w + (i << PAGE_SHIFT);
  45                        invalidate_dtlb_entry_no_isync(e);
  46                }
  47        }
  48        asm volatile ("isync\n");
  49}
  50
  51
  52void flush_tlb_all (void)
  53{
  54        __flush_itlb_all();
  55        __flush_dtlb_all();
  56}
  57
  58/* If mm is current, we simply assign the current task a new ASID, thus,
  59 * invalidating all previous tlb entries. If mm is someone else's user mapping,
  60 * wie invalidate the context, thus, when that user mapping is swapped in,
  61 * a new context will be assigned to it.
  62 */
  63
  64void flush_tlb_mm(struct mm_struct *mm)
  65{
  66        if (mm == current->active_mm) {
  67                int flags;
  68                local_save_flags(flags);
  69                __get_new_mmu_context(mm);
  70                __load_mmu_context(mm);
  71                local_irq_restore(flags);
  72        }
  73        else
  74                mm->context = 0;
  75}
  76
  77#define _ITLB_ENTRIES (ITLB_ARF_WAYS << XCHAL_ITLB_ARF_ENTRIES_LOG2)
  78#define _DTLB_ENTRIES (DTLB_ARF_WAYS << XCHAL_DTLB_ARF_ENTRIES_LOG2)
  79#if _ITLB_ENTRIES > _DTLB_ENTRIES
  80# define _TLB_ENTRIES _ITLB_ENTRIES
  81#else
  82# define _TLB_ENTRIES _DTLB_ENTRIES
  83#endif
  84
  85void flush_tlb_range (struct vm_area_struct *vma,
  86                      unsigned long start, unsigned long end)
  87{
  88        struct mm_struct *mm = vma->vm_mm;
  89        unsigned long flags;
  90
  91        if (mm->context == NO_CONTEXT)
  92                return;
  93
  94#if 0
  95        printk("[tlbrange<%02lx,%08lx,%08lx>]\n",
  96                        (unsigned long)mm->context, start, end);
  97#endif
  98        local_save_flags(flags);
  99
 100        if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
 101                int oldpid = get_rasid_register();
 102                set_rasid_register (ASID_INSERT(mm->context));
 103                start &= PAGE_MASK;
 104                if (vma->vm_flags & VM_EXEC)
 105                        while(start < end) {
 106                                invalidate_itlb_mapping(start);
 107                                invalidate_dtlb_mapping(start);
 108                                start += PAGE_SIZE;
 109                        }
 110                else
 111                        while(start < end) {
 112                                invalidate_dtlb_mapping(start);
 113                                start += PAGE_SIZE;
 114                        }
 115
 116                set_rasid_register(oldpid);
 117        } else {
 118                flush_tlb_mm(mm);
 119        }
 120        local_irq_restore(flags);
 121}
 122
 123void flush_tlb_page (struct vm_area_struct *vma, unsigned long page)
 124{
 125        struct mm_struct* mm = vma->vm_mm;
 126        unsigned long flags;
 127        int oldpid;
 128
 129        if(mm->context == NO_CONTEXT)
 130                return;
 131
 132        local_save_flags(flags);
 133
 134        oldpid = get_rasid_register();
 135
 136        if (vma->vm_flags & VM_EXEC)
 137                invalidate_itlb_mapping(page);
 138        invalidate_dtlb_mapping(page);
 139
 140        set_rasid_register(oldpid);
 141
 142        local_irq_restore(flags);
 143}
 144
 145