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1da177e4 LT |
1 | /* |
2 | * c 2001 PPC 64 Team, IBM Corp | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | */ | |
9 | ||
10 | #include <linux/slab.h> | |
11 | #include <linux/vmalloc.h> | |
12 | ||
13 | #include <asm/uaccess.h> | |
14 | #include <asm/pgalloc.h> | |
15 | #include <asm/pgtable.h> | |
14cc3e2b | 16 | #include <linux/mutex.h> |
20cee16c | 17 | #include <asm/cacheflush.h> |
1da177e4 | 18 | |
800fc3ee DG |
19 | #include "mmu_decl.h" |
20 | ||
14cc3e2b | 21 | static DEFINE_MUTEX(imlist_mutex); |
1da177e4 LT |
22 | struct vm_struct * imlist = NULL; |
23 | ||
24 | static int get_free_im_addr(unsigned long size, unsigned long *im_addr) | |
25 | { | |
26 | unsigned long addr; | |
27 | struct vm_struct **p, *tmp; | |
28 | ||
1f8d419e | 29 | addr = ioremap_bot; |
1da177e4 LT |
30 | for (p = &imlist; (tmp = *p) ; p = &tmp->next) { |
31 | if (size + addr < (unsigned long) tmp->addr) | |
32 | break; | |
1f8d419e | 33 | if ((unsigned long)tmp->addr >= ioremap_bot) |
1da177e4 | 34 | addr = tmp->size + (unsigned long) tmp->addr; |
e28f7faf | 35 | if (addr >= IMALLOC_END-size) |
1da177e4 LT |
36 | return 1; |
37 | } | |
38 | *im_addr = addr; | |
39 | ||
40 | return 0; | |
41 | } | |
42 | ||
43 | /* Return whether the region described by v_addr and size is a subset | |
44 | * of the region described by parent | |
45 | */ | |
46 | static inline int im_region_is_subset(unsigned long v_addr, unsigned long size, | |
47 | struct vm_struct *parent) | |
48 | { | |
49 | return (int) (v_addr >= (unsigned long) parent->addr && | |
50 | v_addr < (unsigned long) parent->addr + parent->size && | |
51 | size < parent->size); | |
52 | } | |
53 | ||
54 | /* Return whether the region described by v_addr and size is a superset | |
55 | * of the region described by child | |
56 | */ | |
57 | static int im_region_is_superset(unsigned long v_addr, unsigned long size, | |
58 | struct vm_struct *child) | |
59 | { | |
60 | struct vm_struct parent; | |
61 | ||
62 | parent.addr = (void *) v_addr; | |
63 | parent.size = size; | |
64 | ||
65 | return im_region_is_subset((unsigned long) child->addr, child->size, | |
66 | &parent); | |
67 | } | |
68 | ||
69 | /* Return whether the region described by v_addr and size overlaps | |
70 | * the region described by vm. Overlapping regions meet the | |
71 | * following conditions: | |
72 | * 1) The regions share some part of the address space | |
73 | * 2) The regions aren't identical | |
74 | * 3) Neither region is a subset of the other | |
75 | */ | |
76 | static int im_region_overlaps(unsigned long v_addr, unsigned long size, | |
77 | struct vm_struct *vm) | |
78 | { | |
79 | if (im_region_is_superset(v_addr, size, vm)) | |
80 | return 0; | |
81 | ||
82 | return (v_addr + size > (unsigned long) vm->addr + vm->size && | |
83 | v_addr < (unsigned long) vm->addr + vm->size) || | |
84 | (v_addr < (unsigned long) vm->addr && | |
85 | v_addr + size > (unsigned long) vm->addr); | |
86 | } | |
87 | ||
88 | /* Determine imalloc status of region described by v_addr and size. | |
89 | * Can return one of the following: | |
90 | * IM_REGION_UNUSED - Entire region is unallocated in imalloc space. | |
91 | * IM_REGION_SUBSET - Region is a subset of a region that is already | |
92 | * allocated in imalloc space. | |
93 | * vm will be assigned to a ptr to the parent region. | |
94 | * IM_REGION_EXISTS - Exact region already allocated in imalloc space. | |
95 | * vm will be assigned to a ptr to the existing imlist | |
96 | * member. | |
97 | * IM_REGION_OVERLAPS - Region overlaps an allocated region in imalloc space. | |
98 | * IM_REGION_SUPERSET - Region is a superset of a region that is already | |
99 | * allocated in imalloc space. | |
100 | */ | |
101 | static int im_region_status(unsigned long v_addr, unsigned long size, | |
102 | struct vm_struct **vm) | |
103 | { | |
104 | struct vm_struct *tmp; | |
105 | ||
106 | for (tmp = imlist; tmp; tmp = tmp->next) | |
107 | if (v_addr < (unsigned long) tmp->addr + tmp->size) | |
108 | break; | |
109 | ||
021c7335 | 110 | *vm = NULL; |
1da177e4 LT |
111 | if (tmp) { |
112 | if (im_region_overlaps(v_addr, size, tmp)) | |
113 | return IM_REGION_OVERLAP; | |
114 | ||
115 | *vm = tmp; | |
116 | if (im_region_is_subset(v_addr, size, tmp)) { | |
117 | /* Return with tmp pointing to superset */ | |
118 | return IM_REGION_SUBSET; | |
119 | } | |
120 | if (im_region_is_superset(v_addr, size, tmp)) { | |
121 | /* Return with tmp pointing to first subset */ | |
122 | return IM_REGION_SUPERSET; | |
123 | } | |
124 | else if (v_addr == (unsigned long) tmp->addr && | |
125 | size == tmp->size) { | |
126 | /* Return with tmp pointing to exact region */ | |
127 | return IM_REGION_EXISTS; | |
128 | } | |
129 | } | |
130 | ||
1da177e4 LT |
131 | return IM_REGION_UNUSED; |
132 | } | |
133 | ||
134 | static struct vm_struct * split_im_region(unsigned long v_addr, | |
135 | unsigned long size, struct vm_struct *parent) | |
136 | { | |
137 | struct vm_struct *vm1 = NULL; | |
138 | struct vm_struct *vm2 = NULL; | |
139 | struct vm_struct *new_vm = NULL; | |
140 | ||
5cbded58 | 141 | vm1 = kmalloc(sizeof(*vm1), GFP_KERNEL); |
1da177e4 LT |
142 | if (vm1 == NULL) { |
143 | printk(KERN_ERR "%s() out of memory\n", __FUNCTION__); | |
144 | return NULL; | |
145 | } | |
146 | ||
147 | if (v_addr == (unsigned long) parent->addr) { | |
148 | /* Use existing parent vm_struct to represent child, allocate | |
149 | * new one for the remainder of parent range | |
150 | */ | |
151 | vm1->size = parent->size - size; | |
152 | vm1->addr = (void *) (v_addr + size); | |
153 | vm1->next = parent->next; | |
154 | ||
155 | parent->size = size; | |
156 | parent->next = vm1; | |
157 | new_vm = parent; | |
158 | } else if (v_addr + size == (unsigned long) parent->addr + | |
159 | parent->size) { | |
160 | /* Allocate new vm_struct to represent child, use existing | |
161 | * parent one for remainder of parent range | |
162 | */ | |
163 | vm1->size = size; | |
164 | vm1->addr = (void *) v_addr; | |
165 | vm1->next = parent->next; | |
166 | new_vm = vm1; | |
167 | ||
168 | parent->size -= size; | |
169 | parent->next = vm1; | |
170 | } else { | |
171 | /* Allocate two new vm_structs for the new child and | |
172 | * uppermost remainder, and use existing parent one for the | |
173 | * lower remainder of parent range | |
174 | */ | |
5cbded58 | 175 | vm2 = kmalloc(sizeof(*vm2), GFP_KERNEL); |
1da177e4 LT |
176 | if (vm2 == NULL) { |
177 | printk(KERN_ERR "%s() out of memory\n", __FUNCTION__); | |
178 | kfree(vm1); | |
179 | return NULL; | |
180 | } | |
181 | ||
182 | vm1->size = size; | |
183 | vm1->addr = (void *) v_addr; | |
184 | vm1->next = vm2; | |
185 | new_vm = vm1; | |
186 | ||
187 | vm2->size = ((unsigned long) parent->addr + parent->size) - | |
188 | (v_addr + size); | |
189 | vm2->addr = (void *) v_addr + size; | |
190 | vm2->next = parent->next; | |
191 | ||
192 | parent->size = v_addr - (unsigned long) parent->addr; | |
193 | parent->next = vm1; | |
194 | } | |
195 | ||
196 | return new_vm; | |
197 | } | |
198 | ||
199 | static struct vm_struct * __add_new_im_area(unsigned long req_addr, | |
200 | unsigned long size) | |
201 | { | |
202 | struct vm_struct **p, *tmp, *area; | |
203 | ||
204 | for (p = &imlist; (tmp = *p) ; p = &tmp->next) { | |
205 | if (req_addr + size <= (unsigned long)tmp->addr) | |
206 | break; | |
207 | } | |
208 | ||
5cbded58 | 209 | area = kmalloc(sizeof(*area), GFP_KERNEL); |
1da177e4 LT |
210 | if (!area) |
211 | return NULL; | |
212 | area->flags = 0; | |
213 | area->addr = (void *)req_addr; | |
214 | area->size = size; | |
215 | area->next = *p; | |
216 | *p = area; | |
217 | ||
218 | return area; | |
219 | } | |
220 | ||
221 | static struct vm_struct * __im_get_area(unsigned long req_addr, | |
222 | unsigned long size, | |
223 | int criteria) | |
224 | { | |
225 | struct vm_struct *tmp; | |
226 | int status; | |
227 | ||
228 | status = im_region_status(req_addr, size, &tmp); | |
229 | if ((criteria & status) == 0) { | |
230 | return NULL; | |
231 | } | |
232 | ||
233 | switch (status) { | |
234 | case IM_REGION_UNUSED: | |
235 | tmp = __add_new_im_area(req_addr, size); | |
236 | break; | |
237 | case IM_REGION_SUBSET: | |
238 | tmp = split_im_region(req_addr, size, tmp); | |
239 | break; | |
240 | case IM_REGION_EXISTS: | |
241 | /* Return requested region */ | |
242 | break; | |
243 | case IM_REGION_SUPERSET: | |
244 | /* Return first existing subset of requested region */ | |
245 | break; | |
246 | default: | |
247 | printk(KERN_ERR "%s() unexpected imalloc region status\n", | |
248 | __FUNCTION__); | |
249 | tmp = NULL; | |
250 | } | |
251 | ||
252 | return tmp; | |
253 | } | |
254 | ||
255 | struct vm_struct * im_get_free_area(unsigned long size) | |
256 | { | |
257 | struct vm_struct *area; | |
258 | unsigned long addr; | |
259 | ||
14cc3e2b | 260 | mutex_lock(&imlist_mutex); |
1da177e4 LT |
261 | if (get_free_im_addr(size, &addr)) { |
262 | printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n", | |
263 | __FUNCTION__, size); | |
264 | area = NULL; | |
265 | goto next_im_done; | |
266 | } | |
267 | ||
268 | area = __im_get_area(addr, size, IM_REGION_UNUSED); | |
269 | if (area == NULL) { | |
270 | printk(KERN_ERR | |
271 | "%s() cannot obtain area for addr 0x%lx size 0x%lx\n", | |
272 | __FUNCTION__, addr, size); | |
273 | } | |
274 | next_im_done: | |
14cc3e2b | 275 | mutex_unlock(&imlist_mutex); |
1da177e4 LT |
276 | return area; |
277 | } | |
278 | ||
279 | struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size, | |
280 | int criteria) | |
281 | { | |
282 | struct vm_struct *area; | |
283 | ||
14cc3e2b | 284 | mutex_lock(&imlist_mutex); |
1da177e4 | 285 | area = __im_get_area(v_addr, size, criteria); |
14cc3e2b | 286 | mutex_unlock(&imlist_mutex); |
1da177e4 LT |
287 | return area; |
288 | } | |
289 | ||
20cee16c | 290 | void im_free(void * addr) |
1da177e4 LT |
291 | { |
292 | struct vm_struct **p, *tmp; | |
1da177e4 LT |
293 | |
294 | if (!addr) | |
20cee16c DG |
295 | return; |
296 | if ((unsigned long) addr & ~PAGE_MASK) { | |
1da177e4 | 297 | printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__, addr); |
20cee16c | 298 | return; |
1da177e4 | 299 | } |
14cc3e2b | 300 | mutex_lock(&imlist_mutex); |
1da177e4 LT |
301 | for (p = &imlist ; (tmp = *p) ; p = &tmp->next) { |
302 | if (tmp->addr == addr) { | |
1da177e4 | 303 | *p = tmp->next; |
20cee16c | 304 | unmap_vm_area(tmp); |
1da177e4 | 305 | kfree(tmp); |
14cc3e2b | 306 | mutex_unlock(&imlist_mutex); |
20cee16c | 307 | return; |
1da177e4 LT |
308 | } |
309 | } | |
14cc3e2b | 310 | mutex_unlock(&imlist_mutex); |
1da177e4 LT |
311 | printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__, |
312 | addr); | |
1da177e4 | 313 | } |