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Commit | Line | Data |
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f8de50eb KA |
1 | /* |
2 | * Copyright (c) 2006, Intel Corporation. | |
3 | * | |
4 | * This file is released under the GPLv2. | |
5 | * | |
98bcef56 | 6 | * Copyright (C) 2006-2008 Intel Corporation |
7 | * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> | |
f8de50eb KA |
8 | */ |
9 | ||
38717946 | 10 | #include <linux/iova.h> |
f8de50eb KA |
11 | |
12 | void | |
f661197e | 13 | init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit) |
f8de50eb KA |
14 | { |
15 | spin_lock_init(&iovad->iova_alloc_lock); | |
16 | spin_lock_init(&iovad->iova_rbtree_lock); | |
17 | iovad->rbroot = RB_ROOT; | |
18 | iovad->cached32_node = NULL; | |
f661197e | 19 | iovad->dma_32bit_pfn = pfn_32bit; |
f8de50eb KA |
20 | } |
21 | ||
22 | static struct rb_node * | |
23 | __get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn) | |
24 | { | |
f661197e | 25 | if ((*limit_pfn != iovad->dma_32bit_pfn) || |
f8de50eb KA |
26 | (iovad->cached32_node == NULL)) |
27 | return rb_last(&iovad->rbroot); | |
28 | else { | |
29 | struct rb_node *prev_node = rb_prev(iovad->cached32_node); | |
30 | struct iova *curr_iova = | |
31 | container_of(iovad->cached32_node, struct iova, node); | |
32 | *limit_pfn = curr_iova->pfn_lo - 1; | |
33 | return prev_node; | |
34 | } | |
35 | } | |
36 | ||
37 | static void | |
38 | __cached_rbnode_insert_update(struct iova_domain *iovad, | |
39 | unsigned long limit_pfn, struct iova *new) | |
40 | { | |
f661197e | 41 | if (limit_pfn != iovad->dma_32bit_pfn) |
f8de50eb KA |
42 | return; |
43 | iovad->cached32_node = &new->node; | |
44 | } | |
45 | ||
46 | static void | |
47 | __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) | |
48 | { | |
49 | struct iova *cached_iova; | |
50 | struct rb_node *curr; | |
51 | ||
52 | if (!iovad->cached32_node) | |
53 | return; | |
54 | curr = iovad->cached32_node; | |
55 | cached_iova = container_of(curr, struct iova, node); | |
56 | ||
57 | if (free->pfn_lo >= cached_iova->pfn_lo) | |
58 | iovad->cached32_node = rb_next(&free->node); | |
59 | } | |
60 | ||
f76aec76 KA |
61 | /* Computes the padding size required, to make the |
62 | * the start address naturally aligned on its size | |
63 | */ | |
64 | static int | |
65 | iova_get_pad_size(int size, unsigned int limit_pfn) | |
66 | { | |
67 | unsigned int pad_size = 0; | |
68 | unsigned int order = ilog2(size); | |
69 | ||
70 | if (order) | |
71 | pad_size = (limit_pfn + 1) % (1 << order); | |
72 | ||
73 | return pad_size; | |
74 | } | |
75 | ||
ddf02886 | 76 | static int __alloc_and_insert_iova_range(struct iova_domain *iovad, |
77 | unsigned long size, unsigned long limit_pfn, | |
78 | struct iova *new, bool size_aligned) | |
f8de50eb | 79 | { |
ddf02886 | 80 | struct rb_node *prev, *curr = NULL; |
f8de50eb KA |
81 | unsigned long flags; |
82 | unsigned long saved_pfn; | |
f76aec76 | 83 | unsigned int pad_size = 0; |
f8de50eb KA |
84 | |
85 | /* Walk the tree backwards */ | |
86 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
87 | saved_pfn = limit_pfn; | |
88 | curr = __get_cached_rbnode(iovad, &limit_pfn); | |
ddf02886 | 89 | prev = curr; |
f8de50eb KA |
90 | while (curr) { |
91 | struct iova *curr_iova = container_of(curr, struct iova, node); | |
ddf02886 | 92 | |
f8de50eb KA |
93 | if (limit_pfn < curr_iova->pfn_lo) |
94 | goto move_left; | |
f76aec76 | 95 | else if (limit_pfn < curr_iova->pfn_hi) |
f8de50eb | 96 | goto adjust_limit_pfn; |
f76aec76 KA |
97 | else { |
98 | if (size_aligned) | |
99 | pad_size = iova_get_pad_size(size, limit_pfn); | |
100 | if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn) | |
101 | break; /* found a free slot */ | |
102 | } | |
f8de50eb KA |
103 | adjust_limit_pfn: |
104 | limit_pfn = curr_iova->pfn_lo - 1; | |
105 | move_left: | |
ddf02886 | 106 | prev = curr; |
f8de50eb KA |
107 | curr = rb_prev(curr); |
108 | } | |
109 | ||
f76aec76 KA |
110 | if (!curr) { |
111 | if (size_aligned) | |
112 | pad_size = iova_get_pad_size(size, limit_pfn); | |
113 | if ((IOVA_START_PFN + size + pad_size) > limit_pfn) { | |
114 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
115 | return -ENOMEM; | |
116 | } | |
f8de50eb | 117 | } |
f76aec76 KA |
118 | |
119 | /* pfn_lo will point to size aligned address if size_aligned is set */ | |
120 | new->pfn_lo = limit_pfn - (size + pad_size) + 1; | |
121 | new->pfn_hi = new->pfn_lo + size - 1; | |
f8de50eb | 122 | |
ddf02886 | 123 | /* Insert the new_iova into domain rbtree by holding writer lock */ |
124 | /* Add new node and rebalance tree. */ | |
125 | { | |
126 | struct rb_node **entry = &((prev)), *parent = NULL; | |
127 | /* Figure out where to put new node */ | |
128 | while (*entry) { | |
129 | struct iova *this = container_of(*entry, | |
130 | struct iova, node); | |
131 | parent = *entry; | |
132 | ||
133 | if (new->pfn_lo < this->pfn_lo) | |
134 | entry = &((*entry)->rb_left); | |
135 | else if (new->pfn_lo > this->pfn_lo) | |
136 | entry = &((*entry)->rb_right); | |
137 | else | |
138 | BUG(); /* this should not happen */ | |
139 | } | |
140 | ||
141 | /* Add new node and rebalance tree. */ | |
142 | rb_link_node(&new->node, parent, entry); | |
143 | rb_insert_color(&new->node, &iovad->rbroot); | |
144 | } | |
145 | __cached_rbnode_insert_update(iovad, saved_pfn, new); | |
146 | ||
f8de50eb | 147 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
ddf02886 | 148 | |
149 | ||
f8de50eb KA |
150 | return 0; |
151 | } | |
152 | ||
153 | static void | |
154 | iova_insert_rbtree(struct rb_root *root, struct iova *iova) | |
155 | { | |
156 | struct rb_node **new = &(root->rb_node), *parent = NULL; | |
157 | /* Figure out where to put new node */ | |
158 | while (*new) { | |
159 | struct iova *this = container_of(*new, struct iova, node); | |
160 | parent = *new; | |
161 | ||
162 | if (iova->pfn_lo < this->pfn_lo) | |
163 | new = &((*new)->rb_left); | |
164 | else if (iova->pfn_lo > this->pfn_lo) | |
165 | new = &((*new)->rb_right); | |
166 | else | |
167 | BUG(); /* this should not happen */ | |
168 | } | |
169 | /* Add new node and rebalance tree. */ | |
170 | rb_link_node(&iova->node, parent, new); | |
171 | rb_insert_color(&iova->node, root); | |
172 | } | |
173 | ||
174 | /** | |
175 | * alloc_iova - allocates an iova | |
176 | * @iovad - iova domain in question | |
177 | * @size - size of page frames to allocate | |
178 | * @limit_pfn - max limit address | |
f76aec76 | 179 | * @size_aligned - set if size_aligned address range is required |
f8de50eb | 180 | * This function allocates an iova in the range limit_pfn to IOVA_START_PFN |
f76aec76 KA |
181 | * looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned |
182 | * flag is set then the allocated address iova->pfn_lo will be naturally | |
183 | * aligned on roundup_power_of_two(size). | |
f8de50eb KA |
184 | */ |
185 | struct iova * | |
186 | alloc_iova(struct iova_domain *iovad, unsigned long size, | |
f76aec76 KA |
187 | unsigned long limit_pfn, |
188 | bool size_aligned) | |
f8de50eb KA |
189 | { |
190 | unsigned long flags; | |
191 | struct iova *new_iova; | |
192 | int ret; | |
193 | ||
194 | new_iova = alloc_iova_mem(); | |
195 | if (!new_iova) | |
196 | return NULL; | |
197 | ||
f76aec76 KA |
198 | /* If size aligned is set then round the size to |
199 | * to next power of two. | |
200 | */ | |
201 | if (size_aligned) | |
202 | size = __roundup_pow_of_two(size); | |
203 | ||
f8de50eb | 204 | spin_lock_irqsave(&iovad->iova_alloc_lock, flags); |
ddf02886 | 205 | ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn, |
206 | new_iova, size_aligned); | |
f8de50eb | 207 | |
ddf02886 | 208 | spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags); |
f8de50eb | 209 | if (ret) { |
f8de50eb KA |
210 | free_iova_mem(new_iova); |
211 | return NULL; | |
212 | } | |
213 | ||
f8de50eb KA |
214 | return new_iova; |
215 | } | |
216 | ||
217 | /** | |
218 | * find_iova - find's an iova for a given pfn | |
219 | * @iovad - iova domain in question. | |
220 | * pfn - page frame number | |
221 | * This function finds and returns an iova belonging to the | |
222 | * given doamin which matches the given pfn. | |
223 | */ | |
224 | struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn) | |
225 | { | |
226 | unsigned long flags; | |
227 | struct rb_node *node; | |
228 | ||
229 | /* Take the lock so that no other thread is manipulating the rbtree */ | |
230 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
231 | node = iovad->rbroot.rb_node; | |
232 | while (node) { | |
233 | struct iova *iova = container_of(node, struct iova, node); | |
234 | ||
235 | /* If pfn falls within iova's range, return iova */ | |
236 | if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) { | |
237 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
238 | /* We are not holding the lock while this iova | |
239 | * is referenced by the caller as the same thread | |
240 | * which called this function also calls __free_iova() | |
241 | * and it is by desing that only one thread can possibly | |
242 | * reference a particular iova and hence no conflict. | |
243 | */ | |
244 | return iova; | |
245 | } | |
246 | ||
247 | if (pfn < iova->pfn_lo) | |
248 | node = node->rb_left; | |
249 | else if (pfn > iova->pfn_lo) | |
250 | node = node->rb_right; | |
251 | } | |
252 | ||
253 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
254 | return NULL; | |
255 | } | |
256 | ||
257 | /** | |
258 | * __free_iova - frees the given iova | |
259 | * @iovad: iova domain in question. | |
260 | * @iova: iova in question. | |
261 | * Frees the given iova belonging to the giving domain | |
262 | */ | |
263 | void | |
264 | __free_iova(struct iova_domain *iovad, struct iova *iova) | |
265 | { | |
266 | unsigned long flags; | |
267 | ||
268 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
269 | __cached_rbnode_delete_update(iovad, iova); | |
270 | rb_erase(&iova->node, &iovad->rbroot); | |
271 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
272 | free_iova_mem(iova); | |
273 | } | |
274 | ||
275 | /** | |
276 | * free_iova - finds and frees the iova for a given pfn | |
277 | * @iovad: - iova domain in question. | |
278 | * @pfn: - pfn that is allocated previously | |
279 | * This functions finds an iova for a given pfn and then | |
280 | * frees the iova from that domain. | |
281 | */ | |
282 | void | |
283 | free_iova(struct iova_domain *iovad, unsigned long pfn) | |
284 | { | |
285 | struct iova *iova = find_iova(iovad, pfn); | |
286 | if (iova) | |
287 | __free_iova(iovad, iova); | |
288 | ||
289 | } | |
290 | ||
291 | /** | |
292 | * put_iova_domain - destroys the iova doamin | |
293 | * @iovad: - iova domain in question. | |
294 | * All the iova's in that domain are destroyed. | |
295 | */ | |
296 | void put_iova_domain(struct iova_domain *iovad) | |
297 | { | |
298 | struct rb_node *node; | |
299 | unsigned long flags; | |
300 | ||
301 | spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); | |
302 | node = rb_first(&iovad->rbroot); | |
303 | while (node) { | |
304 | struct iova *iova = container_of(node, struct iova, node); | |
305 | rb_erase(node, &iovad->rbroot); | |
306 | free_iova_mem(iova); | |
307 | node = rb_first(&iovad->rbroot); | |
308 | } | |
309 | spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); | |
310 | } | |
311 | ||
312 | static int | |
313 | __is_range_overlap(struct rb_node *node, | |
314 | unsigned long pfn_lo, unsigned long pfn_hi) | |
315 | { | |
316 | struct iova *iova = container_of(node, struct iova, node); | |
317 | ||
318 | if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo)) | |
319 | return 1; | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static struct iova * | |
324 | __insert_new_range(struct iova_domain *iovad, | |
325 | unsigned long pfn_lo, unsigned long pfn_hi) | |
326 | { | |
327 | struct iova *iova; | |
328 | ||
329 | iova = alloc_iova_mem(); | |
330 | if (!iova) | |
331 | return iova; | |
332 | ||
333 | iova->pfn_hi = pfn_hi; | |
334 | iova->pfn_lo = pfn_lo; | |
335 | iova_insert_rbtree(&iovad->rbroot, iova); | |
336 | return iova; | |
337 | } | |
338 | ||
339 | static void | |
340 | __adjust_overlap_range(struct iova *iova, | |
341 | unsigned long *pfn_lo, unsigned long *pfn_hi) | |
342 | { | |
343 | if (*pfn_lo < iova->pfn_lo) | |
344 | iova->pfn_lo = *pfn_lo; | |
345 | if (*pfn_hi > iova->pfn_hi) | |
346 | *pfn_lo = iova->pfn_hi + 1; | |
347 | } | |
348 | ||
349 | /** | |
350 | * reserve_iova - reserves an iova in the given range | |
351 | * @iovad: - iova domain pointer | |
352 | * @pfn_lo: - lower page frame address | |
353 | * @pfn_hi:- higher pfn adderss | |
354 | * This function allocates reserves the address range from pfn_lo to pfn_hi so | |
355 | * that this address is not dished out as part of alloc_iova. | |
356 | */ | |
357 | struct iova * | |
358 | reserve_iova(struct iova_domain *iovad, | |
359 | unsigned long pfn_lo, unsigned long pfn_hi) | |
360 | { | |
361 | struct rb_node *node; | |
362 | unsigned long flags; | |
363 | struct iova *iova; | |
364 | unsigned int overlap = 0; | |
365 | ||
366 | spin_lock_irqsave(&iovad->iova_alloc_lock, flags); | |
367 | spin_lock(&iovad->iova_rbtree_lock); | |
368 | for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) { | |
369 | if (__is_range_overlap(node, pfn_lo, pfn_hi)) { | |
370 | iova = container_of(node, struct iova, node); | |
371 | __adjust_overlap_range(iova, &pfn_lo, &pfn_hi); | |
372 | if ((pfn_lo >= iova->pfn_lo) && | |
373 | (pfn_hi <= iova->pfn_hi)) | |
374 | goto finish; | |
375 | overlap = 1; | |
376 | ||
377 | } else if (overlap) | |
378 | break; | |
379 | } | |
380 | ||
381 | /* We are here either becasue this is the first reserver node | |
382 | * or need to insert remaining non overlap addr range | |
383 | */ | |
384 | iova = __insert_new_range(iovad, pfn_lo, pfn_hi); | |
385 | finish: | |
386 | ||
387 | spin_unlock(&iovad->iova_rbtree_lock); | |
388 | spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags); | |
389 | return iova; | |
390 | } | |
391 | ||
392 | /** | |
393 | * copy_reserved_iova - copies the reserved between domains | |
394 | * @from: - source doamin from where to copy | |
395 | * @to: - destination domin where to copy | |
396 | * This function copies reserved iova's from one doamin to | |
397 | * other. | |
398 | */ | |
399 | void | |
400 | copy_reserved_iova(struct iova_domain *from, struct iova_domain *to) | |
401 | { | |
402 | unsigned long flags; | |
403 | struct rb_node *node; | |
404 | ||
405 | spin_lock_irqsave(&from->iova_alloc_lock, flags); | |
406 | spin_lock(&from->iova_rbtree_lock); | |
407 | for (node = rb_first(&from->rbroot); node; node = rb_next(node)) { | |
408 | struct iova *iova = container_of(node, struct iova, node); | |
409 | struct iova *new_iova; | |
410 | new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi); | |
411 | if (!new_iova) | |
412 | printk(KERN_ERR "Reserve iova range %lx@%lx failed\n", | |
413 | iova->pfn_lo, iova->pfn_lo); | |
414 | } | |
415 | spin_unlock(&from->iova_rbtree_lock); | |
416 | spin_unlock_irqrestore(&from->iova_alloc_lock, flags); | |
417 | } |