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> |
85b45456 RM |
21 | #include <linux/slab.h> |
22 | ||
23 | static struct kmem_cache *iommu_iova_cache; | |
24 | ||
25 | int iommu_iova_cache_init(void) | |
26 | { | |
27 | int ret = 0; | |
28 | ||
29 | iommu_iova_cache = kmem_cache_create("iommu_iova", | |
30 | sizeof(struct iova), | |
31 | 0, | |
32 | SLAB_HWCACHE_ALIGN, | |
33 | NULL); | |
34 | if (!iommu_iova_cache) { | |
35 | pr_err("Couldn't create iova cache\n"); | |
36 | ret = -ENOMEM; | |
37 | } | |
38 | ||
39 | return ret; | |
40 | } | |
41 | ||
42 | void iommu_iova_cache_destroy(void) | |
43 | { | |
44 | kmem_cache_destroy(iommu_iova_cache); | |
45 | } | |
46 | ||
47 | struct iova *alloc_iova_mem(void) | |
48 | { | |
49 | return kmem_cache_alloc(iommu_iova_cache, GFP_ATOMIC); | |
50 | } | |
51 | ||
52 | void free_iova_mem(struct iova *iova) | |
53 | { | |
54 | kmem_cache_free(iommu_iova_cache, iova); | |
55 | } | |
f8de50eb KA |
56 | |
57 | void | |
f661197e | 58 | init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit) |
f8de50eb | 59 | { |
f8de50eb KA |
60 | spin_lock_init(&iovad->iova_rbtree_lock); |
61 | iovad->rbroot = RB_ROOT; | |
62 | iovad->cached32_node = NULL; | |
f661197e | 63 | iovad->dma_32bit_pfn = pfn_32bit; |
f8de50eb KA |
64 | } |
65 | ||
66 | static struct rb_node * | |
67 | __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn) | |
68 | { | |
f661197e | 69 | if ((*limit_pfn != iovad->dma_32bit_pfn) || |
f8de50eb KA |
70 | (iovad->cached32_node == NULL)) |
71 | return rb_last(&iovad->rbroot); | |
72 | else { | |
73 | struct rb_node *prev_node = rb_prev(iovad->cached32_node); | |
74 | struct iova *curr_iova = | |
75 | container_of(iovad->cached32_node, struct iova, node); | |
76 | *limit_pfn = curr_iova->pfn_lo - 1; | |
77 | return prev_node; | |
78 | } | |
79 | } | |
80 | ||
81 | static void | |
82 | __cached_rbnode_insert_update(struct iova_domain *iovad, | |
83 | unsigned long limit_pfn, struct iova *new) | |
84 | { | |
f661197e | 85 | if (limit_pfn != iovad->dma_32bit_pfn) |
f8de50eb KA |
86 | return; |
87 | iovad->cached32_node = &new->node; | |
88 | } | |
89 | ||
90 | static void | |
91 | __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) | |
92 | { | |
93 | struct iova *cached_iova; | |
94 | struct rb_node *curr; | |
95 | ||
96 | if (!iovad->cached32_node) | |
97 | return; | |
98 | curr = iovad->cached32_node; | |
99 | cached_iova = container_of(curr, struct iova, node); | |
100 | ||
1c9fc3d1 CW |
101 | if (free->pfn_lo >= cached_iova->pfn_lo) { |
102 | struct rb_node *node = rb_next(&free->node); | |
103 | struct iova *iova = container_of(node, struct iova, node); | |
104 | ||
105 | /* only cache if it's below 32bit pfn */ | |
106 | if (node && iova->pfn_lo < iovad->dma_32bit_pfn) | |
107 | iovad->cached32_node = node; | |
108 | else | |
109 | iovad->cached32_node = NULL; | |
110 | } | |
f8de50eb KA |
111 | } |
112 | ||
f76aec76 KA |
113 | /* Computes the padding size required, to make the |
114 | * the start address naturally aligned on its size | |
115 | */ | |
116 | static int | |
117 | iova_get_pad_size(int size, unsigned int limit_pfn) | |
118 | { | |
119 | unsigned int pad_size = 0; | |
120 | unsigned int order = ilog2(size); | |
121 | ||
122 | if (order) | |
123 | pad_size = (limit_pfn + 1) % (1 << order); | |
124 | ||
125 | return pad_size; | |
126 | } | |
127 | ||
ddf02886 | 128 | static int __alloc_and_insert_iova_range(struct iova_domain *iovad, |
129 | unsigned long size, unsigned long limit_pfn, | |
130 | struct iova *new, bool size_aligned) | |
f8de50eb | 131 | { |
ddf02886 | 132 | struct rb_node *prev, *curr = NULL; |
f8de50eb KA |
133 | unsigned long flags; |
134 | unsigned long saved_pfn; | |
f76aec76 | 135 | unsigned int pad_size = 0; |
f8de50eb KA |
136 | |
137 | /* Walk the tree backwards */ | |
138 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
139 | saved_pfn = limit_pfn; | |
140 | curr = __get_cached_rbnode(iovad, &limit_pfn); | |
ddf02886 | 141 | prev = curr; |
f8de50eb KA |
142 | while (curr) { |
143 | struct iova *curr_iova = container_of(curr, struct iova, node); | |
ddf02886 | 144 | |
f8de50eb KA |
145 | if (limit_pfn < curr_iova->pfn_lo) |
146 | goto move_left; | |
f76aec76 | 147 | else if (limit_pfn < curr_iova->pfn_hi) |
f8de50eb | 148 | goto adjust_limit_pfn; |
f76aec76 KA |
149 | else { |
150 | if (size_aligned) | |
151 | pad_size = iova_get_pad_size(size, limit_pfn); | |
152 | if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn) | |
153 | break; /* found a free slot */ | |
154 | } | |
f8de50eb KA |
155 | adjust_limit_pfn: |
156 | limit_pfn = curr_iova->pfn_lo - 1; | |
157 | move_left: | |
ddf02886 | 158 | prev = curr; |
f8de50eb KA |
159 | curr = rb_prev(curr); |
160 | } | |
161 | ||
f76aec76 KA |
162 | if (!curr) { |
163 | if (size_aligned) | |
164 | pad_size = iova_get_pad_size(size, limit_pfn); | |
165 | if ((IOVA_START_PFN + size + pad_size) > limit_pfn) { | |
166 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
167 | return -ENOMEM; | |
168 | } | |
f8de50eb | 169 | } |
f76aec76 KA |
170 | |
171 | /* pfn_lo will point to size aligned address if size_aligned is set */ | |
172 | new->pfn_lo = limit_pfn - (size + pad_size) + 1; | |
173 | new->pfn_hi = new->pfn_lo + size - 1; | |
f8de50eb | 174 | |
ddf02886 | 175 | /* Insert the new_iova into domain rbtree by holding writer lock */ |
176 | /* Add new node and rebalance tree. */ | |
177 | { | |
a15a519e DW |
178 | struct rb_node **entry, *parent = NULL; |
179 | ||
180 | /* If we have 'prev', it's a valid place to start the | |
181 | insertion. Otherwise, start from the root. */ | |
182 | if (prev) | |
183 | entry = &prev; | |
184 | else | |
185 | entry = &iovad->rbroot.rb_node; | |
186 | ||
ddf02886 | 187 | /* Figure out where to put new node */ |
188 | while (*entry) { | |
189 | struct iova *this = container_of(*entry, | |
190 | struct iova, node); | |
191 | parent = *entry; | |
192 | ||
193 | if (new->pfn_lo < this->pfn_lo) | |
194 | entry = &((*entry)->rb_left); | |
195 | else if (new->pfn_lo > this->pfn_lo) | |
196 | entry = &((*entry)->rb_right); | |
197 | else | |
198 | BUG(); /* this should not happen */ | |
199 | } | |
200 | ||
201 | /* Add new node and rebalance tree. */ | |
202 | rb_link_node(&new->node, parent, entry); | |
203 | rb_insert_color(&new->node, &iovad->rbroot); | |
204 | } | |
205 | __cached_rbnode_insert_update(iovad, saved_pfn, new); | |
206 | ||
f8de50eb | 207 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
ddf02886 | 208 | |
209 | ||
f8de50eb KA |
210 | return 0; |
211 | } | |
212 | ||
213 | static void | |
214 | iova_insert_rbtree(struct rb_root *root, struct iova *iova) | |
215 | { | |
216 | struct rb_node **new = &(root->rb_node), *parent = NULL; | |
217 | /* Figure out where to put new node */ | |
218 | while (*new) { | |
219 | struct iova *this = container_of(*new, struct iova, node); | |
220 | parent = *new; | |
221 | ||
222 | if (iova->pfn_lo < this->pfn_lo) | |
223 | new = &((*new)->rb_left); | |
224 | else if (iova->pfn_lo > this->pfn_lo) | |
225 | new = &((*new)->rb_right); | |
226 | else | |
227 | BUG(); /* this should not happen */ | |
228 | } | |
229 | /* Add new node and rebalance tree. */ | |
230 | rb_link_node(&iova->node, parent, new); | |
231 | rb_insert_color(&iova->node, root); | |
232 | } | |
233 | ||
234 | /** | |
235 | * alloc_iova - allocates an iova | |
07db0409 MI |
236 | * @iovad: - iova domain in question |
237 | * @size: - size of page frames to allocate | |
238 | * @limit_pfn: - max limit address | |
239 | * @size_aligned: - set if size_aligned address range is required | |
f8de50eb | 240 | * This function allocates an iova in the range limit_pfn to IOVA_START_PFN |
f76aec76 KA |
241 | * looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned |
242 | * flag is set then the allocated address iova->pfn_lo will be naturally | |
243 | * aligned on roundup_power_of_two(size). | |
f8de50eb KA |
244 | */ |
245 | struct iova * | |
246 | alloc_iova(struct iova_domain *iovad, unsigned long size, | |
f76aec76 KA |
247 | unsigned long limit_pfn, |
248 | bool size_aligned) | |
f8de50eb | 249 | { |
f8de50eb KA |
250 | struct iova *new_iova; |
251 | int ret; | |
252 | ||
253 | new_iova = alloc_iova_mem(); | |
254 | if (!new_iova) | |
255 | return NULL; | |
256 | ||
f76aec76 KA |
257 | /* If size aligned is set then round the size to |
258 | * to next power of two. | |
259 | */ | |
260 | if (size_aligned) | |
261 | size = __roundup_pow_of_two(size); | |
262 | ||
ddf02886 | 263 | ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn, |
264 | new_iova, size_aligned); | |
f8de50eb KA |
265 | |
266 | if (ret) { | |
f8de50eb KA |
267 | free_iova_mem(new_iova); |
268 | return NULL; | |
269 | } | |
270 | ||
f8de50eb KA |
271 | return new_iova; |
272 | } | |
273 | ||
274 | /** | |
275 | * find_iova - find's an iova for a given pfn | |
07db0409 MI |
276 | * @iovad: - iova domain in question. |
277 | * @pfn: - page frame number | |
f8de50eb KA |
278 | * This function finds and returns an iova belonging to the |
279 | * given doamin which matches the given pfn. | |
280 | */ | |
281 | struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn) | |
282 | { | |
283 | unsigned long flags; | |
284 | struct rb_node *node; | |
285 | ||
286 | /* Take the lock so that no other thread is manipulating the rbtree */ | |
287 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
288 | node = iovad->rbroot.rb_node; | |
289 | while (node) { | |
290 | struct iova *iova = container_of(node, struct iova, node); | |
291 | ||
292 | /* If pfn falls within iova's range, return iova */ | |
293 | if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) { | |
294 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
295 | /* We are not holding the lock while this iova | |
296 | * is referenced by the caller as the same thread | |
297 | * which called this function also calls __free_iova() | |
07db0409 | 298 | * and it is by design that only one thread can possibly |
f8de50eb KA |
299 | * reference a particular iova and hence no conflict. |
300 | */ | |
301 | return iova; | |
302 | } | |
303 | ||
304 | if (pfn < iova->pfn_lo) | |
305 | node = node->rb_left; | |
306 | else if (pfn > iova->pfn_lo) | |
307 | node = node->rb_right; | |
308 | } | |
309 | ||
310 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
311 | return NULL; | |
312 | } | |
313 | ||
314 | /** | |
315 | * __free_iova - frees the given iova | |
316 | * @iovad: iova domain in question. | |
317 | * @iova: iova in question. | |
318 | * Frees the given iova belonging to the giving domain | |
319 | */ | |
320 | void | |
321 | __free_iova(struct iova_domain *iovad, struct iova *iova) | |
322 | { | |
323 | unsigned long flags; | |
324 | ||
325 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
326 | __cached_rbnode_delete_update(iovad, iova); | |
327 | rb_erase(&iova->node, &iovad->rbroot); | |
328 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
329 | free_iova_mem(iova); | |
330 | } | |
331 | ||
332 | /** | |
333 | * free_iova - finds and frees the iova for a given pfn | |
334 | * @iovad: - iova domain in question. | |
335 | * @pfn: - pfn that is allocated previously | |
336 | * This functions finds an iova for a given pfn and then | |
337 | * frees the iova from that domain. | |
338 | */ | |
339 | void | |
340 | free_iova(struct iova_domain *iovad, unsigned long pfn) | |
341 | { | |
342 | struct iova *iova = find_iova(iovad, pfn); | |
343 | if (iova) | |
344 | __free_iova(iovad, iova); | |
345 | ||
346 | } | |
347 | ||
348 | /** | |
349 | * put_iova_domain - destroys the iova doamin | |
350 | * @iovad: - iova domain in question. | |
351 | * All the iova's in that domain are destroyed. | |
352 | */ | |
353 | void put_iova_domain(struct iova_domain *iovad) | |
354 | { | |
355 | struct rb_node *node; | |
356 | unsigned long flags; | |
357 | ||
358 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
359 | node = rb_first(&iovad->rbroot); | |
360 | while (node) { | |
361 | struct iova *iova = container_of(node, struct iova, node); | |
362 | rb_erase(node, &iovad->rbroot); | |
363 | free_iova_mem(iova); | |
364 | node = rb_first(&iovad->rbroot); | |
365 | } | |
366 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
367 | } | |
368 | ||
369 | static int | |
370 | __is_range_overlap(struct rb_node *node, | |
371 | unsigned long pfn_lo, unsigned long pfn_hi) | |
372 | { | |
373 | struct iova *iova = container_of(node, struct iova, node); | |
374 | ||
375 | if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo)) | |
376 | return 1; | |
377 | return 0; | |
378 | } | |
379 | ||
75f05569 JL |
380 | static inline struct iova * |
381 | alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi) | |
382 | { | |
383 | struct iova *iova; | |
384 | ||
385 | iova = alloc_iova_mem(); | |
386 | if (iova) { | |
387 | iova->pfn_lo = pfn_lo; | |
388 | iova->pfn_hi = pfn_hi; | |
389 | } | |
390 | ||
391 | return iova; | |
392 | } | |
393 | ||
f8de50eb KA |
394 | static struct iova * |
395 | __insert_new_range(struct iova_domain *iovad, | |
396 | unsigned long pfn_lo, unsigned long pfn_hi) | |
397 | { | |
398 | struct iova *iova; | |
399 | ||
75f05569 JL |
400 | iova = alloc_and_init_iova(pfn_lo, pfn_hi); |
401 | if (iova) | |
402 | iova_insert_rbtree(&iovad->rbroot, iova); | |
f8de50eb | 403 | |
f8de50eb KA |
404 | return iova; |
405 | } | |
406 | ||
407 | static void | |
408 | __adjust_overlap_range(struct iova *iova, | |
409 | unsigned long *pfn_lo, unsigned long *pfn_hi) | |
410 | { | |
411 | if (*pfn_lo < iova->pfn_lo) | |
412 | iova->pfn_lo = *pfn_lo; | |
413 | if (*pfn_hi > iova->pfn_hi) | |
414 | *pfn_lo = iova->pfn_hi + 1; | |
415 | } | |
416 | ||
417 | /** | |
418 | * reserve_iova - reserves an iova in the given range | |
419 | * @iovad: - iova domain pointer | |
420 | * @pfn_lo: - lower page frame address | |
421 | * @pfn_hi:- higher pfn adderss | |
422 | * This function allocates reserves the address range from pfn_lo to pfn_hi so | |
423 | * that this address is not dished out as part of alloc_iova. | |
424 | */ | |
425 | struct iova * | |
426 | reserve_iova(struct iova_domain *iovad, | |
427 | unsigned long pfn_lo, unsigned long pfn_hi) | |
428 | { | |
429 | struct rb_node *node; | |
430 | unsigned long flags; | |
431 | struct iova *iova; | |
432 | unsigned int overlap = 0; | |
433 | ||
3d39cecc | 434 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); |
f8de50eb KA |
435 | for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) { |
436 | if (__is_range_overlap(node, pfn_lo, pfn_hi)) { | |
437 | iova = container_of(node, struct iova, node); | |
438 | __adjust_overlap_range(iova, &pfn_lo, &pfn_hi); | |
439 | if ((pfn_lo >= iova->pfn_lo) && | |
440 | (pfn_hi <= iova->pfn_hi)) | |
441 | goto finish; | |
442 | overlap = 1; | |
443 | ||
444 | } else if (overlap) | |
445 | break; | |
446 | } | |
447 | ||
25985edc | 448 | /* We are here either because this is the first reserver node |
f8de50eb KA |
449 | * or need to insert remaining non overlap addr range |
450 | */ | |
451 | iova = __insert_new_range(iovad, pfn_lo, pfn_hi); | |
452 | finish: | |
453 | ||
3d39cecc | 454 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
f8de50eb KA |
455 | return iova; |
456 | } | |
457 | ||
458 | /** | |
459 | * copy_reserved_iova - copies the reserved between domains | |
460 | * @from: - source doamin from where to copy | |
461 | * @to: - destination domin where to copy | |
462 | * This function copies reserved iova's from one doamin to | |
463 | * other. | |
464 | */ | |
465 | void | |
466 | copy_reserved_iova(struct iova_domain *from, struct iova_domain *to) | |
467 | { | |
468 | unsigned long flags; | |
469 | struct rb_node *node; | |
470 | ||
3d39cecc | 471 | spin_lock_irqsave(&from->iova_rbtree_lock, flags); |
f8de50eb KA |
472 | for (node = rb_first(&from->rbroot); node; node = rb_next(node)) { |
473 | struct iova *iova = container_of(node, struct iova, node); | |
474 | struct iova *new_iova; | |
475 | new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi); | |
476 | if (!new_iova) | |
477 | printk(KERN_ERR "Reserve iova range %lx@%lx failed\n", | |
478 | iova->pfn_lo, iova->pfn_lo); | |
479 | } | |
3d39cecc | 480 | spin_unlock_irqrestore(&from->iova_rbtree_lock, flags); |
f8de50eb | 481 | } |
75f05569 JL |
482 | |
483 | struct iova * | |
484 | split_and_remove_iova(struct iova_domain *iovad, struct iova *iova, | |
485 | unsigned long pfn_lo, unsigned long pfn_hi) | |
486 | { | |
487 | unsigned long flags; | |
488 | struct iova *prev = NULL, *next = NULL; | |
489 | ||
490 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
491 | if (iova->pfn_lo < pfn_lo) { | |
492 | prev = alloc_and_init_iova(iova->pfn_lo, pfn_lo - 1); | |
493 | if (prev == NULL) | |
494 | goto error; | |
495 | } | |
496 | if (iova->pfn_hi > pfn_hi) { | |
497 | next = alloc_and_init_iova(pfn_hi + 1, iova->pfn_hi); | |
498 | if (next == NULL) | |
499 | goto error; | |
500 | } | |
501 | ||
502 | __cached_rbnode_delete_update(iovad, iova); | |
503 | rb_erase(&iova->node, &iovad->rbroot); | |
504 | ||
505 | if (prev) { | |
506 | iova_insert_rbtree(&iovad->rbroot, prev); | |
507 | iova->pfn_lo = pfn_lo; | |
508 | } | |
509 | if (next) { | |
510 | iova_insert_rbtree(&iovad->rbroot, next); | |
511 | iova->pfn_hi = pfn_hi; | |
512 | } | |
513 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
514 | ||
515 | return iova; | |
516 | ||
517 | error: | |
518 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
519 | if (prev) | |
520 | free_iova_mem(prev); | |
521 | return NULL; | |
522 | } |