File: /usr/src/linux/arch/mips64/mm/umap.c
1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 Linus Torvalds
7 * Copyright (C) 1997 Miguel de Icaza
8 * Copyright (C) 2001 Ralf Baechle
9 */
10 #include <linux/stat.h>
11 #include <linux/sched.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/smp_lock.h>
16 #include <linux/shm.h>
17 #include <linux/errno.h>
18 #include <linux/mman.h>
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/vmalloc.h>
22 #include <linux/swap.h>
23
24 #include <asm/system.h>
25 #include <asm/pgalloc.h>
26 #include <asm/page.h>
27
28 static inline void remove_mapping_pte_range (pmd_t *pmd, unsigned long address,
29 unsigned long size)
30 {
31 pte_t *pte;
32 unsigned long end;
33
34 if (pmd_none (*pmd))
35 return;
36 if (pmd_bad (*pmd)){
37 printk ("remove_graphics_pte_range: bad pmd (%08lx)\n",
38 pmd_val (*pmd));
39 pmd_clear (pmd);
40 return;
41 }
42 pte = pte_offset (pmd, address);
43 address &= ~PMD_MASK;
44 end = address + size;
45 if (end > PMD_SIZE)
46 end = PMD_SIZE;
47 do {
48 pte_t entry = *pte;
49 if (pte_present (entry))
50 set_pte (pte, pte_modify (entry, PAGE_NONE));
51 address += PAGE_SIZE;
52 pte++;
53 } while (address < end);
54
55 }
56
57 static inline void remove_mapping_pmd_range (pgd_t *pgd, unsigned long address,
58 unsigned long size)
59 {
60 pmd_t *pmd;
61 unsigned long end;
62
63 if (pgd_none (*pgd))
64 return;
65
66 if (pgd_bad (*pgd)){
67 printk ("remove_graphics_pmd_range: bad pgd (%08lx)\n",
68 pgd_val (*pgd));
69 pgd_clear (pgd);
70 return;
71 }
72 pmd = pmd_offset (pgd, address);
73 address &= ~PGDIR_MASK;
74 end = address + size;
75 if (end > PGDIR_SIZE)
76 end = PGDIR_SIZE;
77 do {
78 remove_mapping_pte_range (pmd, address, end - address);
79 address = (address + PMD_SIZE) & PMD_MASK;
80 pmd++;
81 } while (address < end);
82
83 }
84
85 /*
86 * This routine is called from the page fault handler to remove a
87 * range of active mappings at this point
88 */
89 void remove_mapping (struct task_struct *task, unsigned long start,
90 unsigned long end)
91 {
92 unsigned long beg = start;
93 pgd_t *dir;
94
95 down_write (&task->mm->mmap_sem);
96 dir = pgd_offset (task->mm, start);
97 flush_cache_range (task->mm, beg, end);
98 while (start < end){
99 remove_mapping_pmd_range (dir, start, end - start);
100 start = (start + PGDIR_SIZE) & PGDIR_MASK;
101 dir++;
102 }
103 flush_tlb_range (task->mm, beg, end);
104 up_write (&task->mm->mmap_sem);
105 }
106
107 EXPORT_SYMBOL(remove_mapping);
108
109 void *vmalloc_uncached (unsigned long size)
110 {
111 return __vmalloc (size, GFP_KERNEL | __GFP_HIGHMEM,
112 PAGE_KERNEL_UNCACHED);
113 }
114
115 static inline void free_pte(pte_t page)
116 {
117 if (pte_present(page)) {
118 struct page *ptpage = pte_page(page);
119 if ((!VALID_PAGE(ptpage)) || PageReserved(ptpage))
120 return;
121 __free_page(ptpage);
122 if (current->mm->rss <= 0)
123 return;
124 current->mm->rss--;
125 return;
126 }
127 swap_free(pte_to_swp_entry(page));
128 }
129
130 static inline void forget_pte(pte_t page)
131 {
132 if (!pte_none(page)) {
133 printk("forget_pte: old mapping existed!\n");
134 free_pte(page);
135 }
136 }
137
138 /*
139 * maps a range of vmalloc()ed memory into the requested pages. the old
140 * mappings are removed.
141 */
142 static inline void vmap_pte_range (pte_t *pte, unsigned long address,
143 unsigned long size, unsigned long vaddr)
144 {
145 unsigned long end;
146 pgd_t *vdir;
147 pmd_t *vpmd;
148 pte_t *vpte;
149
150 address &= ~PMD_MASK;
151 end = address + size;
152 if (end > PMD_SIZE)
153 end = PMD_SIZE;
154 do {
155 pte_t oldpage = *pte;
156 struct page * page;
157 pte_clear(pte);
158
159 vdir = pgd_offset_k (vaddr);
160 vpmd = pmd_offset (vdir, vaddr);
161 vpte = pte_offset (vpmd, vaddr);
162 page = pte_page (*vpte);
163
164 set_pte(pte, mk_pte(page, PAGE_USERIO));
165 forget_pte(oldpage);
166 address += PAGE_SIZE;
167 vaddr += PAGE_SIZE;
168 pte++;
169 } while (address < end);
170 }
171
172 static inline int vmap_pmd_range (pmd_t *pmd, unsigned long address,
173 unsigned long size, unsigned long vaddr)
174 {
175 unsigned long end;
176
177 address &= ~PGDIR_MASK;
178 end = address + size;
179 if (end > PGDIR_SIZE)
180 end = PGDIR_SIZE;
181 vaddr -= address;
182 do {
183 pte_t * pte = pte_alloc(current->mm, pmd, address);
184 if (!pte)
185 return -ENOMEM;
186 vmap_pte_range(pte, address, end - address, address + vaddr);
187 address = (address + PMD_SIZE) & PMD_MASK;
188 pmd++;
189 } while (address < end);
190 return 0;
191 }
192
193 int vmap_page_range (unsigned long from, unsigned long size,
194 unsigned long vaddr)
195 {
196 int error = 0;
197 pgd_t * dir;
198 unsigned long beg = from;
199 unsigned long end = from + size;
200
201 vaddr -= from;
202 dir = pgd_offset(current->mm, from);
203 flush_cache_range(current->mm, beg, end);
204 while (from < end) {
205 pmd_t *pmd = pmd_alloc(current->mm, dir, from);
206 error = -ENOMEM;
207 if (!pmd)
208 break;
209 error = vmap_pmd_range(pmd, from, end - from, vaddr + from);
210 if (error)
211 break;
212 from = (from + PGDIR_SIZE) & PGDIR_MASK;
213 dir++;
214 }
215 flush_tlb_range(current->mm, beg, end);
216 return error;
217 }
218