LXR linux/arch/powerpc/mm/tlb

   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 */
  40void 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}
  49EXPORT_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 */
  55void 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 */
  66void 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
  90static 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 */
 125void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 126{
 127        flush_range(&init_mm, start, end);
 128}
 129EXPORT_SYMBOL(flush_tlb_kernel_range);
 130
 131/*
 132 * Flush all the (user) entries for the address space described by mm.
 133 */
 134void 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}
 152EXPORT_SYMBOL(flush_tlb_mm);
 153
 154void 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}
 168EXPORT_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 */
 175void 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}
 180EXPORT_SYMBOL(flush_tlb_range);
 181
 182void __init early_init_mmu(void)
 183{
 184}
 185