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/cacheflush.h>
  22
  23
  24 static inline void __flush_itlb_all (void)
  25 {
  26         int w, i;
  27
  28         for (w = 0; w < ITLB_ARF_WAYS; w++) {
  29                 for (i = 0; i < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); i++) {
  30                         int e = w + (i << PAGE_SHIFT);
  31                         invalidate_itlb_entry_no_isync(e);
  32                 }
  33         }
  34         asm volatile ("isync\n");
  35 }
  36
  37 static inline void __flush_dtlb_all (void)
  38 {
  39         int w, i;
  40
  41         for (w = 0; w < DTLB_ARF_WAYS; w++) {
  42                 for (i = 0; i < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); i++) {
  43                         int e = w + (i << PAGE_SHIFT);
  44                         invalidate_dtlb_entry_no_isync(e);
  45                 }
  46         }
  47         asm volatile ("isync\n");
  48 }
  49
  50
  51 void flush_tlb_all (void)
  52 {
  53         __flush_itlb_all();
  54         __flush_dtlb_all();
  55 }
  56
  57 /* If mm is current, we simply assign the current task a new ASID, thus,
  58  * invalidating all previous tlb entries. If mm is someone else's user mapping,
  59  * wie invalidate the context, thus, when that user mapping is swapped in,
  60  * a new context will be assigned to it.
  61  */
  62
  63 void flush_tlb_mm(struct mm_struct *mm)
  64 {
  65         if (mm == current->active_mm) {
  66                 int flags;
  67                 local_save_flags(flags);
  68                 __get_new_mmu_context(mm);
  69                 __load_mmu_context(mm);
  70                 local_irq_restore(flags);
  71         }
  72         else
  73                 mm->context = 0;
  74 }
  75
  76 #define _ITLB_ENTRIES (ITLB_ARF_WAYS << XCHAL_ITLB_ARF_ENTRIES_LOG2)
  77 #define _DTLB_ENTRIES (DTLB_ARF_WAYS << XCHAL_DTLB_ARF_ENTRIES_LOG2)
  78 #if _ITLB_ENTRIES > _DTLB_ENTRIES
  79 # define _TLB_ENTRIES _ITLB_ENTRIES
  80 #else
  81 # define _TLB_ENTRIES _DTLB_ENTRIES
  82 #endif
  83
  84 void flush_tlb_range (struct vm_area_struct *vma,
  85                       unsigned long start, unsigned long end)
  86 {
  87         struct mm_struct *mm = vma->vm_mm;
  88         unsigned long flags;
  89
  90         if (mm->context == NO_CONTEXT)
  91                 return;
  92
  93 #if 0
  94         printk("[tlbrange<%02lx,%08lx,%08lx>]\n",
  95                         (unsigned long)mm->context, start, end);
  96 #endif
  97         local_save_flags(flags);
  98
  99         if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
 100                 int oldpid = get_rasid_register();
 101                 set_rasid_register (ASID_INSERT(mm->context));
 102                 start &= PAGE_MASK;
 103                 if (vma->vm_flags & VM_EXEC)
 104                         while(start < end) {
 105                                 invalidate_itlb_mapping(start);
 106                                 invalidate_dtlb_mapping(start);
 107                                 start += PAGE_SIZE;
 108                         }
 109                 else
 110                         while(start < end) {
 111                                 invalidate_dtlb_mapping(start);
 112                                 start += PAGE_SIZE;
 113                         }
 114
 115                 set_rasid_register(oldpid);
 116         } else {
 117                 flush_tlb_mm(mm);
 118         }
 119         local_irq_restore(flags);
 120 }
 121
 122 void flush_tlb_page (struct vm_area_struct *vma, unsigned long page)
 123 {
 124         struct mm_struct* mm = vma->vm_mm;
 125         unsigned long flags;
 126         int oldpid;
 127
 128         if(mm->context == NO_CONTEXT)
 129                 return;
 130
 131         local_save_flags(flags);
 132
 133         oldpid = get_rasid_register();
 134
 135         if (vma->vm_flags & VM_EXEC)
 136                 invalidate_itlb_mapping(page);
 137         invalidate_dtlb_mapping(page);
 138
 139         set_rasid_register(oldpid);
 140
 141         local_irq_restore(flags);
 142 }
 143