Commit | Line | Data |
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f8de50eb | 1 | /* |
a15a519e | 2 | * Copyright © 2006-2009, Intel Corporation. |
f8de50eb | 3 | * |
a15a519e DW |
4 | * This program is free software; you can redistribute it and/or modify it |
5 | * under the terms and conditions of the GNU General Public License, | |
6 | * version 2, as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple | |
15 | * Place - Suite 330, Boston, MA 02111-1307 USA. | |
f8de50eb | 16 | * |
98bcef56 | 17 | * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> |
f8de50eb KA |
18 | */ |
19 | ||
38717946 | 20 | #include <linux/iova.h> |
f8de50eb KA |
21 | |
22 | void | |
f661197e | 23 | init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit) |
f8de50eb KA |
24 | { |
25 | spin_lock_init(&iovad->iova_alloc_lock); | |
26 | spin_lock_init(&iovad->iova_rbtree_lock); | |
27 | iovad->rbroot = RB_ROOT; | |
28 | iovad->cached32_node = NULL; | |
f661197e | 29 | iovad->dma_32bit_pfn = pfn_32bit; |
f8de50eb KA |
30 | } |
31 | ||
32 | static struct rb_node * | |
33 | __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn) | |
34 | { | |
f661197e | 35 | if ((*limit_pfn != iovad->dma_32bit_pfn) || |
f8de50eb KA |
36 | (iovad->cached32_node == NULL)) |
37 | return rb_last(&iovad->rbroot); | |
38 | else { | |
39 | struct rb_node *prev_node = rb_prev(iovad->cached32_node); | |
40 | struct iova *curr_iova = | |
41 | container_of(iovad->cached32_node, struct iova, node); | |
42 | *limit_pfn = curr_iova->pfn_lo - 1; | |
43 | return prev_node; | |
44 | } | |
45 | } | |
46 | ||
47 | static void | |
48 | __cached_rbnode_insert_update(struct iova_domain *iovad, | |
49 | unsigned long limit_pfn, struct iova *new) | |
50 | { | |
f661197e | 51 | if (limit_pfn != iovad->dma_32bit_pfn) |
f8de50eb KA |
52 | return; |
53 | iovad->cached32_node = &new->node; | |
54 | } | |
55 | ||
56 | static void | |
57 | __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) | |
58 | { | |
59 | struct iova *cached_iova; | |
60 | struct rb_node *curr; | |
61 | ||
62 | if (!iovad->cached32_node) | |
63 | return; | |
64 | curr = iovad->cached32_node; | |
65 | cached_iova = container_of(curr, struct iova, node); | |
66 | ||
67 | if (free->pfn_lo >= cached_iova->pfn_lo) | |
68 | iovad->cached32_node = rb_next(&free->node); | |
69 | } | |
70 | ||
f76aec76 KA |
71 | /* Computes the padding size required, to make the |
72 | * the start address naturally aligned on its size | |
73 | */ | |
74 | static int | |
75 | iova_get_pad_size(int size, unsigned int limit_pfn) | |
76 | { | |
77 | unsigned int pad_size = 0; | |
78 | unsigned int order = ilog2(size); | |
79 | ||
80 | if (order) | |
81 | pad_size = (limit_pfn + 1) % (1 << order); | |
82 | ||
83 | return pad_size; | |
84 | } | |
85 | ||
ddf02886 | 86 | static int __alloc_and_insert_iova_range(struct iova_domain *iovad, |
87 | unsigned long size, unsigned long limit_pfn, | |
88 | struct iova *new, bool size_aligned) | |
f8de50eb | 89 | { |
ddf02886 | 90 | struct rb_node *prev, *curr = NULL; |
f8de50eb KA |
91 | unsigned long flags; |
92 | unsigned long saved_pfn; | |
f76aec76 | 93 | unsigned int pad_size = 0; |
f8de50eb KA |
94 | |
95 | /* Walk the tree backwards */ | |
96 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
97 | saved_pfn = limit_pfn; | |
98 | curr = __get_cached_rbnode(iovad, &limit_pfn); | |
ddf02886 | 99 | prev = curr; |
f8de50eb KA |
100 | while (curr) { |
101 | struct iova *curr_iova = container_of(curr, struct iova, node); | |
ddf02886 | 102 | |
f8de50eb KA |
103 | if (limit_pfn < curr_iova->pfn_lo) |
104 | goto move_left; | |
f76aec76 | 105 | else if (limit_pfn < curr_iova->pfn_hi) |
f8de50eb | 106 | goto adjust_limit_pfn; |
f76aec76 KA |
107 | else { |
108 | if (size_aligned) | |
109 | pad_size = iova_get_pad_size(size, limit_pfn); | |
110 | if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn) | |
111 | break; /* found a free slot */ | |
112 | } | |
f8de50eb KA |
113 | adjust_limit_pfn: |
114 | limit_pfn = curr_iova->pfn_lo - 1; | |
115 | move_left: | |
ddf02886 | 116 | prev = curr; |
f8de50eb KA |
117 | curr = rb_prev(curr); |
118 | } | |
119 | ||
f76aec76 KA |
120 | if (!curr) { |
121 | if (size_aligned) | |
122 | pad_size = iova_get_pad_size(size, limit_pfn); | |
123 | if ((IOVA_START_PFN + size + pad_size) > limit_pfn) { | |
124 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
125 | return -ENOMEM; | |
126 | } | |
f8de50eb | 127 | } |
f76aec76 KA |
128 | |
129 | /* pfn_lo will point to size aligned address if size_aligned is set */ | |
130 | new->pfn_lo = limit_pfn - (size + pad_size) + 1; | |
131 | new->pfn_hi = new->pfn_lo + size - 1; | |
f8de50eb | 132 | |
ddf02886 | 133 | /* Insert the new_iova into domain rbtree by holding writer lock */ |
134 | /* Add new node and rebalance tree. */ | |
135 | { | |
a15a519e DW |
136 | struct rb_node **entry, *parent = NULL; |
137 | ||
138 | /* If we have 'prev', it's a valid place to start the | |
139 | insertion. Otherwise, start from the root. */ | |
140 | if (prev) | |
141 | entry = &prev; | |
142 | else | |
143 | entry = &iovad->rbroot.rb_node; | |
144 | ||
ddf02886 | 145 | /* Figure out where to put new node */ |
146 | while (*entry) { | |
147 | struct iova *this = container_of(*entry, | |
148 | struct iova, node); | |
149 | parent = *entry; | |
150 | ||
151 | if (new->pfn_lo < this->pfn_lo) | |
152 | entry = &((*entry)->rb_left); | |
153 | else if (new->pfn_lo > this->pfn_lo) | |
154 | entry = &((*entry)->rb_right); | |
155 | else | |
156 | BUG(); /* this should not happen */ | |
157 | } | |
158 | ||
159 | /* Add new node and rebalance tree. */ | |
160 | rb_link_node(&new->node, parent, entry); | |
161 | rb_insert_color(&new->node, &iovad->rbroot); | |
162 | } | |
163 | __cached_rbnode_insert_update(iovad, saved_pfn, new); | |
164 | ||
f8de50eb | 165 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
ddf02886 | 166 | |
167 | ||
f8de50eb KA |
168 | return 0; |
169 | } | |
170 | ||
171 | static void | |
172 | iova_insert_rbtree(struct rb_root *root, struct iova *iova) | |
173 | { | |
174 | struct rb_node **new = &(root->rb_node), *parent = NULL; | |
175 | /* Figure out where to put new node */ | |
176 | while (*new) { | |
177 | struct iova *this = container_of(*new, struct iova, node); | |
178 | parent = *new; | |
179 | ||
180 | if (iova->pfn_lo < this->pfn_lo) | |
181 | new = &((*new)->rb_left); | |
182 | else if (iova->pfn_lo > this->pfn_lo) | |
183 | new = &((*new)->rb_right); | |
184 | else | |
185 | BUG(); /* this should not happen */ | |
186 | } | |
187 | /* Add new node and rebalance tree. */ | |
188 | rb_link_node(&iova->node, parent, new); | |
189 | rb_insert_color(&iova->node, root); | |
190 | } | |
191 | ||
192 | /** | |
193 | * alloc_iova - allocates an iova | |
194 | * @iovad - iova domain in question | |
195 | * @size - size of page frames to allocate | |
196 | * @limit_pfn - max limit address | |
f76aec76 | 197 | * @size_aligned - set if size_aligned address range is required |
f8de50eb | 198 | * This function allocates an iova in the range limit_pfn to IOVA_START_PFN |
f76aec76 KA |
199 | * looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned |
200 | * flag is set then the allocated address iova->pfn_lo will be naturally | |
201 | * aligned on roundup_power_of_two(size). | |
f8de50eb KA |
202 | */ |
203 | struct iova * | |
204 | alloc_iova(struct iova_domain *iovad, unsigned long size, | |
f76aec76 KA |
205 | unsigned long limit_pfn, |
206 | bool size_aligned) | |
f8de50eb KA |
207 | { |
208 | unsigned long flags; | |
209 | struct iova *new_iova; | |
210 | int ret; | |
211 | ||
212 | new_iova = alloc_iova_mem(); | |
213 | if (!new_iova) | |
214 | return NULL; | |
215 | ||
f76aec76 KA |
216 | /* If size aligned is set then round the size to |
217 | * to next power of two. | |
218 | */ | |
219 | if (size_aligned) | |
220 | size = __roundup_pow_of_two(size); | |
221 | ||
f8de50eb | 222 | spin_lock_irqsave(&iovad->iova_alloc_lock, flags); |
ddf02886 | 223 | ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn, |
224 | new_iova, size_aligned); | |
f8de50eb | 225 | |
ddf02886 | 226 | spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags); |
f8de50eb | 227 | if (ret) { |
f8de50eb KA |
228 | free_iova_mem(new_iova); |
229 | return NULL; | |
230 | } | |
231 | ||
f8de50eb KA |
232 | return new_iova; |
233 | } | |
234 | ||
235 | /** | |
236 | * find_iova - find's an iova for a given pfn | |
237 | * @iovad - iova domain in question. | |
238 | * pfn - page frame number | |
239 | * This function finds and returns an iova belonging to the | |
240 | * given doamin which matches the given pfn. | |
241 | */ | |
242 | struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn) | |
243 | { | |
244 | unsigned long flags; | |
245 | struct rb_node *node; | |
246 | ||
247 | /* Take the lock so that no other thread is manipulating the rbtree */ | |
248 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
249 | node = iovad->rbroot.rb_node; | |
250 | while (node) { | |
251 | struct iova *iova = container_of(node, struct iova, node); | |
252 | ||
253 | /* If pfn falls within iova's range, return iova */ | |
254 | if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) { | |
255 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
256 | /* We are not holding the lock while this iova | |
257 | * is referenced by the caller as the same thread | |
258 | * which called this function also calls __free_iova() | |
259 | * and it is by desing that only one thread can possibly | |
260 | * reference a particular iova and hence no conflict. | |
261 | */ | |
262 | return iova; | |
263 | } | |
264 | ||
265 | if (pfn < iova->pfn_lo) | |
266 | node = node->rb_left; | |
267 | else if (pfn > iova->pfn_lo) | |
268 | node = node->rb_right; | |
269 | } | |
270 | ||
271 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
272 | return NULL; | |
273 | } | |
274 | ||
275 | /** | |
276 | * __free_iova - frees the given iova | |
277 | * @iovad: iova domain in question. | |
278 | * @iova: iova in question. | |
279 | * Frees the given iova belonging to the giving domain | |
280 | */ | |
281 | void | |
282 | __free_iova(struct iova_domain *iovad, struct iova *iova) | |
283 | { | |
284 | unsigned long flags; | |
285 | ||
286 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
287 | __cached_rbnode_delete_update(iovad, iova); | |
288 | rb_erase(&iova->node, &iovad->rbroot); | |
289 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
290 | free_iova_mem(iova); | |
291 | } | |
292 | ||
293 | /** | |
294 | * free_iova - finds and frees the iova for a given pfn | |
295 | * @iovad: - iova domain in question. | |
296 | * @pfn: - pfn that is allocated previously | |
297 | * This functions finds an iova for a given pfn and then | |
298 | * frees the iova from that domain. | |
299 | */ | |
300 | void | |
301 | free_iova(struct iova_domain *iovad, unsigned long pfn) | |
302 | { | |
303 | struct iova *iova = find_iova(iovad, pfn); | |
304 | if (iova) | |
305 | __free_iova(iovad, iova); | |
306 | ||
307 | } | |
308 | ||
309 | /** | |
310 | * put_iova_domain - destroys the iova doamin | |
311 | * @iovad: - iova domain in question. | |
312 | * All the iova's in that domain are destroyed. | |
313 | */ | |
314 | void put_iova_domain(struct iova_domain *iovad) | |
315 | { | |
316 | struct rb_node *node; | |
317 | unsigned long flags; | |
318 | ||
319 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
320 | node = rb_first(&iovad->rbroot); | |
321 | while (node) { | |
322 | struct iova *iova = container_of(node, struct iova, node); | |
323 | rb_erase(node, &iovad->rbroot); | |
324 | free_iova_mem(iova); | |
325 | node = rb_first(&iovad->rbroot); | |
326 | } | |
327 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
328 | } | |
329 | ||
330 | static int | |
331 | __is_range_overlap(struct rb_node *node, | |
332 | unsigned long pfn_lo, unsigned long pfn_hi) | |
333 | { | |
334 | struct iova *iova = container_of(node, struct iova, node); | |
335 | ||
336 | if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo)) | |
337 | return 1; | |
338 | return 0; | |
339 | } | |
340 | ||
341 | static struct iova * | |
342 | __insert_new_range(struct iova_domain *iovad, | |
343 | unsigned long pfn_lo, unsigned long pfn_hi) | |
344 | { | |
345 | struct iova *iova; | |
346 | ||
347 | iova = alloc_iova_mem(); | |
348 | if (!iova) | |
349 | return iova; | |
350 | ||
351 | iova->pfn_hi = pfn_hi; | |
352 | iova->pfn_lo = pfn_lo; | |
353 | iova_insert_rbtree(&iovad->rbroot, iova); | |
354 | return iova; | |
355 | } | |
356 | ||
357 | static void | |
358 | __adjust_overlap_range(struct iova *iova, | |
359 | unsigned long *pfn_lo, unsigned long *pfn_hi) | |
360 | { | |
361 | if (*pfn_lo < iova->pfn_lo) | |
362 | iova->pfn_lo = *pfn_lo; | |
363 | if (*pfn_hi > iova->pfn_hi) | |
364 | *pfn_lo = iova->pfn_hi + 1; | |
365 | } | |
366 | ||
367 | /** | |
368 | * reserve_iova - reserves an iova in the given range | |
369 | * @iovad: - iova domain pointer | |
370 | * @pfn_lo: - lower page frame address | |
371 | * @pfn_hi:- higher pfn adderss | |
372 | * This function allocates reserves the address range from pfn_lo to pfn_hi so | |
373 | * that this address is not dished out as part of alloc_iova. | |
374 | */ | |
375 | struct iova * | |
376 | reserve_iova(struct iova_domain *iovad, | |
377 | unsigned long pfn_lo, unsigned long pfn_hi) | |
378 | { | |
379 | struct rb_node *node; | |
380 | unsigned long flags; | |
381 | struct iova *iova; | |
382 | unsigned int overlap = 0; | |
383 | ||
384 | spin_lock_irqsave(&iovad->iova_alloc_lock, flags); | |
385 | spin_lock(&iovad->iova_rbtree_lock); | |
386 | for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) { | |
387 | if (__is_range_overlap(node, pfn_lo, pfn_hi)) { | |
388 | iova = container_of(node, struct iova, node); | |
389 | __adjust_overlap_range(iova, &pfn_lo, &pfn_hi); | |
390 | if ((pfn_lo >= iova->pfn_lo) && | |
391 | (pfn_hi <= iova->pfn_hi)) | |
392 | goto finish; | |
393 | overlap = 1; | |
394 | ||
395 | } else if (overlap) | |
396 | break; | |
397 | } | |
398 | ||
399 | /* We are here either becasue this is the first reserver node | |
400 | * or need to insert remaining non overlap addr range | |
401 | */ | |
402 | iova = __insert_new_range(iovad, pfn_lo, pfn_hi); | |
403 | finish: | |
404 | ||
405 | spin_unlock(&iovad->iova_rbtree_lock); | |
406 | spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags); | |
407 | return iova; | |
408 | } | |
409 | ||
410 | /** | |
411 | * copy_reserved_iova - copies the reserved between domains | |
412 | * @from: - source doamin from where to copy | |
413 | * @to: - destination domin where to copy | |
414 | * This function copies reserved iova's from one doamin to | |
415 | * other. | |
416 | */ | |
417 | void | |
418 | copy_reserved_iova(struct iova_domain *from, struct iova_domain *to) | |
419 | { | |
420 | unsigned long flags; | |
421 | struct rb_node *node; | |
422 | ||
423 | spin_lock_irqsave(&from->iova_alloc_lock, flags); | |
424 | spin_lock(&from->iova_rbtree_lock); | |
425 | for (node = rb_first(&from->rbroot); node; node = rb_next(node)) { | |
426 | struct iova *iova = container_of(node, struct iova, node); | |
427 | struct iova *new_iova; | |
428 | new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi); | |
429 | if (!new_iova) | |
430 | printk(KERN_ERR "Reserve iova range %lx@%lx failed\n", | |
431 | iova->pfn_lo, iova->pfn_lo); | |
432 | } | |
433 | spin_unlock(&from->iova_rbtree_lock); | |
434 | spin_unlock_irqrestore(&from->iova_alloc_lock, flags); | |
435 | } |