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 */
flush_hash_entry(struct mm_struct * mm,pte_t * ptep,unsigned long addr)40 void 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 }
49 EXPORT_SYMBOL(flush_hash_entry);
50
51 /*
52 * Called by ptep_set_access_flags, must flush on CPUs for which the
53 * DSI handler can't just "fixup" the TLB on a write fault
54 */
flush_tlb_page_nohash(struct vm_area_struct * vma,unsigned long addr)55 void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr)
56 {
57 if (Hash != 0)
58 return;
59 _tlbie(addr);
60 }
61
62 /*
63 * Called at the end of a mmu_gather operation to make sure the
64 * TLB flush is completely done.
65 */
tlb_flush(struct mmu_gather * tlb)66 void tlb_flush(struct mmu_gather *tlb)
67 {
68 if (Hash == 0) {
69 /*
70 * 603 needs to flush the whole TLB here since
71 * it doesn't use a hash table.
72 */
73 _tlbia();
74 }
75 }
76
77 /*
78 * TLB flushing:
79 *
80 * - flush_tlb_mm(mm) flushes the specified mm context TLB's
81 * - flush_tlb_page(vma, vmaddr) flushes one page
82 * - flush_tlb_range(vma, start, end) flushes a range of pages
83 * - flush_tlb_kernel_range(start, end) flushes kernel pages
84 *
85 * since the hardware hash table functions as an extension of the
86 * tlb as far as the linux tables are concerned, flush it too.
87 * -- Cort
88 */
89
flush_range(struct mm_struct * mm,unsigned long start,unsigned long end)90 static void flush_range(struct mm_struct *mm, unsigned long start,
91 unsigned long end)
92 {
93 pmd_t *pmd;
94 unsigned long pmd_end;
95 int count;
96 unsigned int ctx = mm->context.id;
97
98 if (Hash == 0) {
99 _tlbia();
100 return;
101 }
102 start &= PAGE_MASK;
103 if (start >= end)
104 return;
105 end = (end - 1) | ~PAGE_MASK;
106 pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
107 for (;;) {
108 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
109 if (pmd_end > end)
110 pmd_end = end;
111 if (!pmd_none(*pmd)) {
112 count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
113 flush_hash_pages(ctx, start, pmd_val(*pmd), count);
114 }
115 if (pmd_end == end)
116 break;
117 start = pmd_end + 1;
118 ++pmd;
119 }
120 }
121
122 /*
123 * Flush kernel TLB entries in the given range
124 */
flush_tlb_kernel_range(unsigned long start,unsigned long end)125 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
126 {
127 flush_range(&init_mm, start, end);
128 }
129 EXPORT_SYMBOL(flush_tlb_kernel_range);
130
131 /*
132 * Flush all the (user) entries for the address space described by mm.
133 */
flush_tlb_mm(struct mm_struct * mm)134 void flush_tlb_mm(struct mm_struct *mm)
135 {
136 struct vm_area_struct *mp;
137
138 if (Hash == 0) {
139 _tlbia();
140 return;
141 }
142
143 /*
144 * It is safe to go down the mm's list of vmas when called
145 * from dup_mmap, holding mmap_sem. It would also be safe from
146 * unmap_region or exit_mmap, but not from vmtruncate on SMP -
147 * but it seems dup_mmap is the only SMP case which gets here.
148 */
149 for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
150 flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
151 }
152 EXPORT_SYMBOL(flush_tlb_mm);
153
flush_tlb_page(struct vm_area_struct * vma,unsigned long vmaddr)154 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
155 {
156 struct mm_struct *mm;
157 pmd_t *pmd;
158
159 if (Hash == 0) {
160 _tlbie(vmaddr);
161 return;
162 }
163 mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
164 pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
165 if (!pmd_none(*pmd))
166 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
167 }
168 EXPORT_SYMBOL(flush_tlb_page);
169
170 /*
171 * For each address in the range, find the pte for the address
172 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
173 * the corresponding HPTE.
174 */
flush_tlb_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)175 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
176 unsigned long end)
177 {
178 flush_range(vma->vm_mm, start, end);
179 }
180 EXPORT_SYMBOL(flush_tlb_range);
181
early_init_mmu(void)182 void __init early_init_mmu(void)
183 {
184 }
185