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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc64/mm/imalloc.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ppc64/mm/imalloc.c')
-rw-r--r--arch/ppc64/mm/imalloc.c312
1 files changed, 312 insertions, 0 deletions
diff --git a/arch/ppc64/mm/imalloc.c b/arch/ppc64/mm/imalloc.c
new file mode 100644
index 000000000000..9d92b0d9cde5
--- /dev/null
+++ b/arch/ppc64/mm/imalloc.c
@@ -0,0 +1,312 @@
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>
16#include <asm/semaphore.h>
17
18static DECLARE_MUTEX(imlist_sem);
19struct vm_struct * imlist = NULL;
20
21static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
22{
23 unsigned long addr;
24 struct vm_struct **p, *tmp;
25
26 addr = IMALLOC_START;
27 for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
28 if (size + addr < (unsigned long) tmp->addr)
29 break;
30 if ((unsigned long)tmp->addr >= IMALLOC_START)
31 addr = tmp->size + (unsigned long) tmp->addr;
32 if (addr > IMALLOC_END-size)
33 return 1;
34 }
35 *im_addr = addr;
36
37 return 0;
38}
39
40/* Return whether the region described by v_addr and size is a subset
41 * of the region described by parent
42 */
43static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
44 struct vm_struct *parent)
45{
46 return (int) (v_addr >= (unsigned long) parent->addr &&
47 v_addr < (unsigned long) parent->addr + parent->size &&
48 size < parent->size);
49}
50
51/* Return whether the region described by v_addr and size is a superset
52 * of the region described by child
53 */
54static int im_region_is_superset(unsigned long v_addr, unsigned long size,
55 struct vm_struct *child)
56{
57 struct vm_struct parent;
58
59 parent.addr = (void *) v_addr;
60 parent.size = size;
61
62 return im_region_is_subset((unsigned long) child->addr, child->size,
63 &parent);
64}
65
66/* Return whether the region described by v_addr and size overlaps
67 * the region described by vm. Overlapping regions meet the
68 * following conditions:
69 * 1) The regions share some part of the address space
70 * 2) The regions aren't identical
71 * 3) Neither region is a subset of the other
72 */
73static int im_region_overlaps(unsigned long v_addr, unsigned long size,
74 struct vm_struct *vm)
75{
76 if (im_region_is_superset(v_addr, size, vm))
77 return 0;
78
79 return (v_addr + size > (unsigned long) vm->addr + vm->size &&
80 v_addr < (unsigned long) vm->addr + vm->size) ||
81 (v_addr < (unsigned long) vm->addr &&
82 v_addr + size > (unsigned long) vm->addr);
83}
84
85/* Determine imalloc status of region described by v_addr and size.
86 * Can return one of the following:
87 * IM_REGION_UNUSED - Entire region is unallocated in imalloc space.
88 * IM_REGION_SUBSET - Region is a subset of a region that is already
89 * allocated in imalloc space.
90 * vm will be assigned to a ptr to the parent region.
91 * IM_REGION_EXISTS - Exact region already allocated in imalloc space.
92 * vm will be assigned to a ptr to the existing imlist
93 * member.
94 * IM_REGION_OVERLAPS - Region overlaps an allocated region in imalloc space.
95 * IM_REGION_SUPERSET - Region is a superset of a region that is already
96 * allocated in imalloc space.
97 */
98static int im_region_status(unsigned long v_addr, unsigned long size,
99 struct vm_struct **vm)
100{
101 struct vm_struct *tmp;
102
103 for (tmp = imlist; tmp; tmp = tmp->next)
104 if (v_addr < (unsigned long) tmp->addr + tmp->size)
105 break;
106
107 if (tmp) {
108 if (im_region_overlaps(v_addr, size, tmp))
109 return IM_REGION_OVERLAP;
110
111 *vm = tmp;
112 if (im_region_is_subset(v_addr, size, tmp)) {
113 /* Return with tmp pointing to superset */
114 return IM_REGION_SUBSET;
115 }
116 if (im_region_is_superset(v_addr, size, tmp)) {
117 /* Return with tmp pointing to first subset */
118 return IM_REGION_SUPERSET;
119 }
120 else if (v_addr == (unsigned long) tmp->addr &&
121 size == tmp->size) {
122 /* Return with tmp pointing to exact region */
123 return IM_REGION_EXISTS;
124 }
125 }
126
127 *vm = NULL;
128 return IM_REGION_UNUSED;
129}
130
131static struct vm_struct * split_im_region(unsigned long v_addr,
132 unsigned long size, struct vm_struct *parent)
133{
134 struct vm_struct *vm1 = NULL;
135 struct vm_struct *vm2 = NULL;
136 struct vm_struct *new_vm = NULL;
137
138 vm1 = (struct vm_struct *) kmalloc(sizeof(*vm1), GFP_KERNEL);
139 if (vm1 == NULL) {
140 printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
141 return NULL;
142 }
143
144 if (v_addr == (unsigned long) parent->addr) {
145 /* Use existing parent vm_struct to represent child, allocate
146 * new one for the remainder of parent range
147 */
148 vm1->size = parent->size - size;
149 vm1->addr = (void *) (v_addr + size);
150 vm1->next = parent->next;
151
152 parent->size = size;
153 parent->next = vm1;
154 new_vm = parent;
155 } else if (v_addr + size == (unsigned long) parent->addr +
156 parent->size) {
157 /* Allocate new vm_struct to represent child, use existing
158 * parent one for remainder of parent range
159 */
160 vm1->size = size;
161 vm1->addr = (void *) v_addr;
162 vm1->next = parent->next;
163 new_vm = vm1;
164
165 parent->size -= size;
166 parent->next = vm1;
167 } else {
168 /* Allocate two new vm_structs for the new child and
169 * uppermost remainder, and use existing parent one for the
170 * lower remainder of parent range
171 */
172 vm2 = (struct vm_struct *) kmalloc(sizeof(*vm2), GFP_KERNEL);
173 if (vm2 == NULL) {
174 printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
175 kfree(vm1);
176 return NULL;
177 }
178
179 vm1->size = size;
180 vm1->addr = (void *) v_addr;
181 vm1->next = vm2;
182 new_vm = vm1;
183
184 vm2->size = ((unsigned long) parent->addr + parent->size) -
185 (v_addr + size);
186 vm2->addr = (void *) v_addr + size;
187 vm2->next = parent->next;
188
189 parent->size = v_addr - (unsigned long) parent->addr;
190 parent->next = vm1;
191 }
192
193 return new_vm;
194}
195
196static struct vm_struct * __add_new_im_area(unsigned long req_addr,
197 unsigned long size)
198{
199 struct vm_struct **p, *tmp, *area;
200
201 for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
202 if (req_addr + size <= (unsigned long)tmp->addr)
203 break;
204 }
205
206 area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
207 if (!area)
208 return NULL;
209 area->flags = 0;
210 area->addr = (void *)req_addr;
211 area->size = size;
212 area->next = *p;
213 *p = area;
214
215 return area;
216}
217
218static struct vm_struct * __im_get_area(unsigned long req_addr,
219 unsigned long size,
220 int criteria)
221{
222 struct vm_struct *tmp;
223 int status;
224
225 status = im_region_status(req_addr, size, &tmp);
226 if ((criteria & status) == 0) {
227 return NULL;
228 }
229
230 switch (status) {
231 case IM_REGION_UNUSED:
232 tmp = __add_new_im_area(req_addr, size);
233 break;
234 case IM_REGION_SUBSET:
235 tmp = split_im_region(req_addr, size, tmp);
236 break;
237 case IM_REGION_EXISTS:
238 /* Return requested region */
239 break;
240 case IM_REGION_SUPERSET:
241 /* Return first existing subset of requested region */
242 break;
243 default:
244 printk(KERN_ERR "%s() unexpected imalloc region status\n",
245 __FUNCTION__);
246 tmp = NULL;
247 }
248
249 return tmp;
250}
251
252struct vm_struct * im_get_free_area(unsigned long size)
253{
254 struct vm_struct *area;
255 unsigned long addr;
256
257 down(&imlist_sem);
258 if (get_free_im_addr(size, &addr)) {
259 printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n",
260 __FUNCTION__, size);
261 area = NULL;
262 goto next_im_done;
263 }
264
265 area = __im_get_area(addr, size, IM_REGION_UNUSED);
266 if (area == NULL) {
267 printk(KERN_ERR
268 "%s() cannot obtain area for addr 0x%lx size 0x%lx\n",
269 __FUNCTION__, addr, size);
270 }
271next_im_done:
272 up(&imlist_sem);
273 return area;
274}
275
276struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
277 int criteria)
278{
279 struct vm_struct *area;
280
281 down(&imlist_sem);
282 area = __im_get_area(v_addr, size, criteria);
283 up(&imlist_sem);
284 return area;
285}
286
287unsigned long im_free(void * addr)
288{
289 struct vm_struct **p, *tmp;
290 unsigned long ret_size = 0;
291
292 if (!addr)
293 return ret_size;
294 if ((PAGE_SIZE-1) & (unsigned long) addr) {
295 printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__, addr);
296 return ret_size;
297 }
298 down(&imlist_sem);
299 for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
300 if (tmp->addr == addr) {
301 ret_size = tmp->size;
302 *p = tmp->next;
303 kfree(tmp);
304 up(&imlist_sem);
305 return ret_size;
306 }
307 }
308 up(&imlist_sem);
309 printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,
310 addr);
311 return ret_size;
312}