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Linux kernel mirror (for testing)
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linux
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
92/*
93 * 750 SMP is a Bad Idea because the 750 doesn't broadcast all
94 * the cache operations on the bus. Hence we need to use an IPI
95 * to get the other CPU(s) to invalidate their TLBs.
96 */
97#ifdef CONFIG_SMP_750
98#define FINISH_FLUSH smp_send_tlb_invalidate(0)
99#else
100#define FINISH_FLUSH do { } while (0)
101#endif
102
103static void flush_range(struct mm_struct *mm, unsigned long start,
104 unsigned long end)
105{
106 pmd_t *pmd;
107 unsigned long pmd_end;
108 int count;
109 unsigned int ctx = mm->context.id;
110
111 if (Hash == 0) {
112 _tlbia();
113 return;
114 }
115 start &= PAGE_MASK;
116 if (start >= end)
117 return;
118 end = (end - 1) | ~PAGE_MASK;
119 pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
120 for (;;) {
121 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
122 if (pmd_end > end)
123 pmd_end = end;
124 if (!pmd_none(*pmd)) {
125 count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
126 flush_hash_pages(ctx, start, pmd_val(*pmd), count);
127 }
128 if (pmd_end == end)
129 break;
130 start = pmd_end + 1;
131 ++pmd;
132 }
133}
134
135/*
136 * Flush kernel TLB entries in the given range
137 */
138void flush_tlb_kernel_range(unsigned long start, unsigned long end)
139{
140 flush_range(&init_mm, start, end);
141 FINISH_FLUSH;
142}
143EXPORT_SYMBOL(flush_tlb_kernel_range);
144
145/*
146 * Flush all the (user) entries for the address space described by mm.
147 */
148void flush_tlb_mm(struct mm_struct *mm)
149{
150 struct vm_area_struct *mp;
151
152 if (Hash == 0) {
153 _tlbia();
154 return;
155 }
156
157 /*
158 * It is safe to go down the mm's list of vmas when called
159 * from dup_mmap, holding mmap_sem. It would also be safe from
160 * unmap_region or exit_mmap, but not from vmtruncate on SMP -
161 * but it seems dup_mmap is the only SMP case which gets here.
162 */
163 for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
164 flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
165 FINISH_FLUSH;
166}
167EXPORT_SYMBOL(flush_tlb_mm);
168
169void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
170{
171 struct mm_struct *mm;
172 pmd_t *pmd;
173
174 if (Hash == 0) {
175 _tlbie(vmaddr);
176 return;
177 }
178 mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
179 pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
180 if (!pmd_none(*pmd))
181 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
182 FINISH_FLUSH;
183}
184EXPORT_SYMBOL(flush_tlb_page);
185
186/*
187 * For each address in the range, find the pte for the address
188 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
189 * the corresponding HPTE.
190 */
191void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
192 unsigned long end)
193{
194 flush_range(vma->vm_mm, start, end);
195 FINISH_FLUSH;
196}
197EXPORT_SYMBOL(flush_tlb_range);