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
  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 */
  39void 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}
  48EXPORT_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 */
  54void 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 */
  65void 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        /* Push out batch of freed page tables */
  76        pte_free_finish();
  77}
  78
  79/*
  80 * TLB flushing:
  81 *
  82 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
  83 *  - flush_tlb_page(vma, vmaddr) flushes one page
  84 *  - flush_tlb_range(vma, start, end) flushes a range of pages
  85 *  - flush_tlb_kernel_range(start, end) flushes kernel pages
  86 *
  87 * since the hardware hash table functions as an extension of the
  88 * tlb as far as the linux tables are concerned, flush it too.
  89 *    -- Cort
  90 */
  91
  92static void flush_range(struct mm_struct *mm, unsigned long start,
  93                        unsigned long end)
  94{
  95        pmd_t *pmd;
  96        unsigned long pmd_end;
  97        int count;
  98        unsigned int ctx = mm->context.id;
  99
 100        if (Hash == 0) {
 101                _tlbia();
 102                return;
 103        }
 104        start &= PAGE_MASK;
 105        if (start >= end)
 106                return;
 107        end = (end - 1) | ~PAGE_MASK;
 108        pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
 109        for (;;) {
 110                pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
 111                if (pmd_end > end)
 112                        pmd_end = end;
 113                if (!pmd_none(*pmd)) {
 114                        count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
 115                        flush_hash_pages(ctx, start, pmd_val(*pmd), count);
 116                }
 117                if (pmd_end == end)
 118                        break;
 119                start = pmd_end + 1;
 120                ++pmd;
 121        }
 122}
 123
 124/*
 125 * Flush kernel TLB entries in the given range
 126 */
 127void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 128{
 129        flush_range(&init_mm, start, end);
 130}
 131EXPORT_SYMBOL(flush_tlb_kernel_range);
 132
 133/*
 134 * Flush all the (user) entries for the address space described by mm.
 135 */
 136void flush_tlb_mm(struct mm_struct *mm)
 137{
 138        struct vm_area_struct *mp;
 139
 140        if (Hash == 0) {
 141                _tlbia();
 142                return;
 143        }
 144
 145        /*
 146         * It is safe to go down the mm's list of vmas when called
 147         * from dup_mmap, holding mmap_sem.  It would also be safe from
 148         * unmap_region or exit_mmap, but not from vmtruncate on SMP -
 149         * but it seems dup_mmap is the only SMP case which gets here.
 150         */
 151        for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
 152                flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
 153}
 154EXPORT_SYMBOL(flush_tlb_mm);
 155
 156void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
 157{
 158        struct mm_struct *mm;
 159        pmd_t *pmd;
 160
 161        if (Hash == 0) {
 162                _tlbie(vmaddr);
 163                return;
 164        }
 165        mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
 166        pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
 167        if (!pmd_none(*pmd))
 168                flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
 169}
 170EXPORT_SYMBOL(flush_tlb_page);
 171
 172/*
 173 * For each address in the range, find the pte for the address
 174 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
 175 * the corresponding HPTE.
 176 */
 177void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 178                     unsigned long end)
 179{
 180        flush_range(vma->vm_mm, start, end);
 181}
 182EXPORT_SYMBOL(flush_tlb_range);
 183