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 */
flush_hash_entry(struct mm_struct * mm,pte_t * ptep,unsigned long addr)39 void 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 EXPORT_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 */
flush_tlb_page_nohash(struct vm_area_struct * vma,unsigned long addr)54 void 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 */
tlb_flush(struct mmu_gather * tlb)65 void 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
flush_range(struct mm_struct * mm,unsigned long start,unsigned long end)92 static 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 */
flush_tlb_kernel_range(unsigned long start,unsigned long end)127 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
128 {
129 flush_range(&init_mm, start, end);
130 }
131 EXPORT_SYMBOL(flush_tlb_kernel_range);
132
133 /*
134 * Flush all the (user) entries for the address space described by mm.
135 */
flush_tlb_mm(struct mm_struct * mm)136 void 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 }
154 EXPORT_SYMBOL(flush_tlb_mm);
155
flush_tlb_page(struct vm_area_struct * vma,unsigned long vmaddr)156 void 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 }
170 EXPORT_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 */
flush_tlb_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)177 void 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 }
182 EXPORT_SYMBOL(flush_tlb_range);
183