tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
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 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
15 *
16 * Derived from "arch/i386/mm/init.c"
17 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
18 *
19 * This program is free software; you can redistribute it and/or
20 * modify it under the terms of the GNU General Public License
21 * as published by the Free Software Foundation; either version
22 * 2 of the License, or (at your option) any later version.
23 *
24 */
25
26#include <linux/kernel.h>
27#include <linux/mm.h>
28#include <linux/init.h>
29#include <linux/highmem.h>
30#include <linux/pagemap.h>
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}
48
49/*
50 * Called by ptep_set_access_flags, must flush on CPUs for which the
51 * DSI handler can't just "fixup" the TLB on a write fault
52 */
53void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr)
54{
55 if (Hash != 0)
56 return;
57 _tlbie(addr);
58}
59
60/*
61 * Called at the end of a mmu_gather operation to make sure the
62 * TLB flush is completely done.
63 */
64void tlb_flush(struct mmu_gather *tlb)
65{
66 if (Hash == 0) {
67 /*
68 * 603 needs to flush the whole TLB here since
69 * it doesn't use a hash table.
70 */
71 _tlbia();
72 }
73}
74
75/*
76 * TLB flushing:
77 *
78 * - flush_tlb_mm(mm) flushes the specified mm context TLB's
79 * - flush_tlb_page(vma, vmaddr) flushes one page
80 * - flush_tlb_range(vma, start, end) flushes a range of pages
81 * - flush_tlb_kernel_range(start, end) flushes kernel pages
82 *
83 * since the hardware hash table functions as an extension of the
84 * tlb as far as the linux tables are concerned, flush it too.
85 * -- Cort
86 */
87
88/*
89 * 750 SMP is a Bad Idea because the 750 doesn't broadcast all
90 * the cache operations on the bus. Hence we need to use an IPI
91 * to get the other CPU(s) to invalidate their TLBs.
92 */
93#ifdef CONFIG_SMP_750
94#define FINISH_FLUSH smp_send_tlb_invalidate(0)
95#else
96#define FINISH_FLUSH do { } while (0)
97#endif
98
99static void flush_range(struct mm_struct *mm, unsigned long start,
100 unsigned long end)
101{
102 pmd_t *pmd;
103 unsigned long pmd_end;
104 int count;
105 unsigned int ctx = mm->context.id;
106
107 if (Hash == 0) {
108 _tlbia();
109 return;
110 }
111 start &= PAGE_MASK;
112 if (start >= end)
113 return;
114 end = (end - 1) | ~PAGE_MASK;
115 pmd = pmd_offset(pgd_offset(mm, start), start);
116 for (;;) {
117 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
118 if (pmd_end > end)
119 pmd_end = end;
120 if (!pmd_none(*pmd)) {
121 count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
122 flush_hash_pages(ctx, start, pmd_val(*pmd), count);
123 }
124 if (pmd_end == end)
125 break;
126 start = pmd_end + 1;
127 ++pmd;
128 }
129}
130
131/*
132 * Flush kernel TLB entries in the given range
133 */
134void flush_tlb_kernel_range(unsigned long start, unsigned long end)
135{
136 flush_range(&init_mm, start, end);
137 FINISH_FLUSH;
138}
139
140/*
141 * Flush all the (user) entries for the address space described by mm.
142 */
143void flush_tlb_mm(struct mm_struct *mm)
144{
145 struct vm_area_struct *mp;
146
147 if (Hash == 0) {
148 _tlbia();
149 return;
150 }
151
152 for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
153 flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
154 FINISH_FLUSH;
155}
156
157void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
158{
159 struct mm_struct *mm;
160 pmd_t *pmd;
161
162 if (Hash == 0) {
163 _tlbie(vmaddr);
164 return;
165 }
166 mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
167 pmd = pmd_offset(pgd_offset(mm, vmaddr), vmaddr);
168 if (!pmd_none(*pmd))
169 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
170 FINISH_FLUSH;
171}
172
173/*
174 * For each address in the range, find the pte for the address
175 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
176 * the corresponding HPTE.
177 */
178void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
179 unsigned long end)
180{
181 flush_range(vma->vm_mm, start, end);
182 FINISH_FLUSH;
183}