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 at the end of a mmu_gather operation to make sure the
  53  * TLB flush is completely done.
  54  */
  55 void tlb_flush(struct mmu_gather *tlb)
  56 {
  57         if (Hash == 0) {
  58                 /*
  59                  * 603 needs to flush the whole TLB here since
  60                  * it doesn't use a hash table.
  61                  */
  62                 _tlbia();
  63         }
  64 }
  65
  66 /*
  67  * TLB flushing:
  68  *
  69  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
  70  *  - flush_tlb_page(vma, vmaddr) flushes one page
  71  *  - flush_tlb_range(vma, start, end) flushes a range of pages
  72  *  - flush_tlb_kernel_range(start, end) flushes kernel pages
  73  *
  74  * since the hardware hash table functions as an extension of the
  75  * tlb as far as the linux tables are concerned, flush it too.
  76  *    -- Cort
  77  */
  78
  79 static void flush_range(struct mm_struct *mm, unsigned long start,
  80                         unsigned long end)
  81 {
  82         pmd_t *pmd;
  83         unsigned long pmd_end;
  84         int count;
  85         unsigned int ctx = mm->context.id;
  86
  87         if (Hash == 0) {
  88                 _tlbia();
  89                 return;
  90         }
  91         start &= PAGE_MASK;
  92         if (start >= end)
  93                 return;
  94         end = (end - 1) | ~PAGE_MASK;
  95         pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
  96         for (;;) {
  97                 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
  98                 if (pmd_end > end)
  99                         pmd_end = end;
 100                 if (!pmd_none(*pmd)) {
 101                         count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
 102                         flush_hash_pages(ctx, start, pmd_val(*pmd), count);
 103                 }
 104                 if (pmd_end == end)
 105                         break;
 106                 start = pmd_end + 1;
 107                 ++pmd;
 108         }
 109 }
 110
 111 /*
 112  * Flush kernel TLB entries in the given range
 113  */
 114 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 115 {
 116         flush_range(&init_mm, start, end);
 117 }
 118 EXPORT_SYMBOL(flush_tlb_kernel_range);
 119
 120 /*
 121  * Flush all the (user) entries for the address space described by mm.
 122  */
 123 void flush_tlb_mm(struct mm_struct *mm)
 124 {
 125         struct vm_area_struct *mp;
 126
 127         if (Hash == 0) {
 128                 _tlbia();
 129                 return;
 130         }
 131
 132         /*
 133          * It is safe to go down the mm's list of vmas when called
 134          * from dup_mmap, holding mmap_sem.  It would also be safe from
 135          * unmap_region or exit_mmap, but not from vmtruncate on SMP -
 136          * but it seems dup_mmap is the only SMP case which gets here.
 137          */
 138         for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
 139                 flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
 140 }
 141 EXPORT_SYMBOL(flush_tlb_mm);
 142
 143 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
 144 {
 145         struct mm_struct *mm;
 146         pmd_t *pmd;
 147
 148         if (Hash == 0) {
 149                 _tlbie(vmaddr);
 150                 return;
 151         }
 152         mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
 153         pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
 154         if (!pmd_none(*pmd))
 155                 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
 156 }
 157 EXPORT_SYMBOL(flush_tlb_page);
 158
 159 /*
 160  * For each address in the range, find the pte for the address
 161  * and check _PAGE_HASHPTE bit; if it is set, find and destroy
 162  * the corresponding HPTE.
 163  */
 164 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 165                      unsigned long end)
 166 {
 167         flush_range(vma->vm_mm, start, end);
 168 }
 169 EXPORT_SYMBOL(flush_tlb_range);
 170
 171 void __init early_init_mmu(void)
 172 {
 173 }