arch/powerpc/mm/tlb_hash32.c

   1 /*
   2  * This file contains the routines for TLB flushing.
   3  * On machines where the MMU uses a hash table to store virtual to
   4  * physical translations, these routines flush entries from the
   5  * hash table also.
   6  *  -- paulus
   7  *
   8  *  Derived from arch/ppc/mm/init.c:
   9  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  10  *
  11  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
  12  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
  13  *    Copyright (C) 1996 Paul Mackerras
  14  *
  15  *  Derived from "arch/i386/mm/init.c"
  16  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  17  *
  18  *  This program is free software; you can redistribute it and/or
  19  *  modify it under the terms of the GNU General Public License
  20  *  as published by the Free Software Foundation; either version
  21  *  2 of the License, or (at your option) any later version.
  22  *
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/mm.h>
  27 #include <linux/init.h>
  28 #include <linux/highmem.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/export.h>
  31
  32 #include <asm/tlbflush.h>
  33 #include <asm/tlb.h>
  34
  35 #include "mmu_decl.h"
  36
  37 /*
  38  * Called when unmapping pages to flush entries from the TLB/hash table.
  39  */
  40 void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr)
  41 {
  42         unsigned long ptephys;
  43
  44         if (Hash != 0) {
  45                 ptephys = __pa(ptep) & PAGE_MASK;
  46                 flush_hash_pages(mm->context.id, addr, ptephys, 1);
  47         }
  48 }
  49 EXPORT_SYMBOL(flush_hash_entry);
  50
  51 /*
  52  * Called by ptep_set_access_flags, must flush on CPUs for which the
  53  * DSI handler can't just "fixup" the TLB on a write fault
  54  */
  55 void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr)
  56 {
  57         if (Hash != 0)
  58                 return;
  59         _tlbie(addr);
  60 }
  61
  62 /*
  63  * Called at the end of a mmu_gather operation to make sure the
  64  * TLB flush is completely done.
  65  */
  66 void tlb_flush(struct mmu_gather *tlb)
  67 {
  68         if (Hash == 0) {
  69                 /*
  70                  * 603 needs to flush the whole TLB here since
  71                  * it doesn't use a hash table.
  72                  */
  73                 _tlbia();
  74         }
  75 }
  76
  77 /*
  78  * TLB flushing:
  79  *
  80  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
  81  *  - flush_tlb_page(vma, vmaddr) flushes one page
  82  *  - flush_tlb_range(vma, start, end) flushes a range of pages
  83  *  - flush_tlb_kernel_range(start, end) flushes kernel pages
  84  *
  85  * since the hardware hash table functions as an extension of the
  86  * tlb as far as the linux tables are concerned, flush it too.
  87  *    -- Cort
  88  */
  89
  90 static void flush_range(struct mm_struct *mm, unsigned long start,
  91                         unsigned long end)
  92 {
  93         pmd_t *pmd;
  94         unsigned long pmd_end;
  95         int count;
  96         unsigned int ctx = mm->context.id;
  97
  98         if (Hash == 0) {
  99                 _tlbia();
 100                 return;
 101         }
 102         start &= PAGE_MASK;
 103         if (start >= end)
 104                 return;
 105         end = (end - 1) | ~PAGE_MASK;
 106         pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
 107         for (;;) {
 108                 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
 109                 if (pmd_end > end)
 110                         pmd_end = end;
 111                 if (!pmd_none(*pmd)) {
 112                         count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
 113                         flush_hash_pages(ctx, start, pmd_val(*pmd), count);
 114                 }
 115                 if (pmd_end == end)
 116                         break;
 117                 start = pmd_end + 1;
 118                 ++pmd;
 119         }
 120 }
 121
 122 /*
 123  * Flush kernel TLB entries in the given range
 124  */
 125 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 126 {
 127         flush_range(&init_mm, start, end);
 128 }
 129 EXPORT_SYMBOL(flush_tlb_kernel_range);
 130
 131 /*
 132  * Flush all the (user) entries for the address space described by mm.
 133  */
 134 void flush_tlb_mm(struct mm_struct *mm)
 135 {
 136         struct vm_area_struct *mp;
 137
 138         if (Hash == 0) {
 139                 _tlbia();
 140                 return;
 141         }
 142
 143         /*
 144          * It is safe to go down the mm's list of vmas when called
 145          * from dup_mmap, holding mmap_sem.  It would also be safe from
 146          * unmap_region or exit_mmap, but not from vmtruncate on SMP -
 147          * but it seems dup_mmap is the only SMP case which gets here.
 148          */
 149         for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
 150                 flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
 151 }
 152 EXPORT_SYMBOL(flush_tlb_mm);
 153
 154 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
 155 {
 156         struct mm_struct *mm;
 157         pmd_t *pmd;
 158
 159         if (Hash == 0) {
 160                 _tlbie(vmaddr);
 161                 return;
 162         }
 163         mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
 164         pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
 165         if (!pmd_none(*pmd))
 166                 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
 167 }
 168 EXPORT_SYMBOL(flush_tlb_page);
 169
 170 /*
 171  * For each address in the range, find the pte for the address
 172  * and check _PAGE_HASHPTE bit; if it is set, find and destroy
 173  * the corresponding HPTE.
 174  */
 175 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 176                      unsigned long end)
 177 {
 178         flush_range(vma->vm_mm, start, end);
 179 }
 180 EXPORT_SYMBOL(flush_tlb_range);
 181
 182 void __init early_init_mmu(void)
 183 {
 184 }