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 at the end of a mmu_gather operation to make sure the
  53 * TLB flush is completely done.
  54 */
  55void 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
  79static 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 */
 114void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 115{
 116        flush_range(&init_mm, start, end);
 117}
 118EXPORT_SYMBOL(flush_tlb_kernel_range);
 119
 120/*
 121 * Flush all the (user) entries for the address space described by mm.
 122 */
 123void 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}
 141EXPORT_SYMBOL(flush_tlb_mm);
 142
 143void 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}
 157EXPORT_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 */
 164void 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}
 169EXPORT_SYMBOL(flush_tlb_range);
 170
 171void __init early_init_mmu(void)
 172{
 173}
 174