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
  31 #include <asm/tlbflush.h>
  32 #include <asm/tlb.h>
  33
  34 #include "mmu_decl.h"
  35
  36 /*
  37  * Called when unmapping pages to flush entries from the TLB/hash table.
  38  */
  39 void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr)
  40 {
  41         unsigned long ptephys;
  42
  43         if (Hash != 0) {
  44                 ptephys = __pa(ptep) & PAGE_MASK;
  45                 flush_hash_pages(mm->context.id, addr, ptephys, 1);
  46         }
  47 }
  48 EXPORT_SYMBOL(flush_hash_entry);
  49
  50 /*
  51  * Called by ptep_set_access_flags, must flush on CPUs for which the
  52  * DSI handler can't just "fixup" the TLB on a write fault
  53  */
  54 void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr)
  55 {
  56         if (Hash != 0)
  57                 return;
  58         _tlbie(addr);
  59 }
  60
  61 /*
  62  * Called at the end of a mmu_gather operation to make sure the
  63  * TLB flush is completely done.
  64  */
  65 void tlb_flush(struct mmu_gather *tlb)
  66 {
  67         if (Hash == 0) {
  68                 /*
  69                  * 603 needs to flush the whole TLB here since
  70                  * it doesn't use a hash table.
  71                  */
  72                 _tlbia();
  73         }
  74 }
  75
  76 /*
  77  * TLB flushing:
  78  *
  79  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
  80  *  - flush_tlb_page(vma, vmaddr) flushes one page
  81  *  - flush_tlb_range(vma, start, end) flushes a range of pages
  82  *  - flush_tlb_kernel_range(start, end) flushes kernel pages
  83  *
  84  * since the hardware hash table functions as an extension of the
  85  * tlb as far as the linux tables are concerned, flush it too.
  86  *    -- Cort
  87  */
  88
  89 static void flush_range(struct mm_struct *mm, unsigned long start,
  90                         unsigned long end)
  91 {
  92         pmd_t *pmd;
  93         unsigned long pmd_end;
  94         int count;
  95         unsigned int ctx = mm->context.id;
  96
  97         if (Hash == 0) {
  98                 _tlbia();
  99                 return;
 100         }
 101         start &= PAGE_MASK;
 102         if (start >= end)
 103                 return;
 104         end = (end - 1) | ~PAGE_MASK;
 105         pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
 106         for (;;) {
 107                 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
 108                 if (pmd_end > end)
 109                         pmd_end = end;
 110                 if (!pmd_none(*pmd)) {
 111                         count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
 112                         flush_hash_pages(ctx, start, pmd_val(*pmd), count);
 113                 }
 114                 if (pmd_end == end)
 115                         break;
 116                 start = pmd_end + 1;
 117                 ++pmd;
 118         }
 119 }
 120
 121 /*
 122  * Flush kernel TLB entries in the given range
 123  */
 124 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 125 {
 126         flush_range(&init_mm, start, end);
 127 }
 128 EXPORT_SYMBOL(flush_tlb_kernel_range);
 129
 130 /*
 131  * Flush all the (user) entries for the address space described by mm.
 132  */
 133 void flush_tlb_mm(struct mm_struct *mm)
 134 {
 135         struct vm_area_struct *mp;
 136
 137         if (Hash == 0) {
 138                 _tlbia();
 139                 return;
 140         }
 141
 142         /*
 143          * It is safe to go down the mm's list of vmas when called
 144          * from dup_mmap, holding mmap_sem.  It would also be safe from
 145          * unmap_region or exit_mmap, but not from vmtruncate on SMP -
 146          * but it seems dup_mmap is the only SMP case which gets here.
 147          */
 148         for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
 149                 flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
 150 }
 151 EXPORT_SYMBOL(flush_tlb_mm);
 152
 153 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
 154 {
 155         struct mm_struct *mm;
 156         pmd_t *pmd;
 157
 158         if (Hash == 0) {
 159                 _tlbie(vmaddr);
 160                 return;
 161         }
 162         mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
 163         pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
 164         if (!pmd_none(*pmd))
 165                 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
 166 }
 167 EXPORT_SYMBOL(flush_tlb_page);
 168
 169 /*
 170  * For each address in the range, find the pte for the address
 171  * and check _PAGE_HASHPTE bit; if it is set, find and destroy
 172  * the corresponding HPTE.
 173  */
 174 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 175                      unsigned long end)
 176 {
 177         flush_range(vma->vm_mm, start, end);
 178 }
 179 EXPORT_SYMBOL(flush_tlb_range);
 180
 181 void __init early_init_mmu(void)
 182 {
 183 }