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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright © 2006-2009, Intel Corporation.
4 *
5 * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
6 */
7
8#include <linux/iova.h>
9#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/smp.h>
12#include <linux/bitops.h>
13#include <linux/cpu.h>
14
15/* The anchor node sits above the top of the usable address space */
16#define IOVA_ANCHOR ~0UL
17
18#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */
19
20static bool iova_rcache_insert(struct iova_domain *iovad,
21 unsigned long pfn,
22 unsigned long size);
23static unsigned long iova_rcache_get(struct iova_domain *iovad,
24 unsigned long size,
25 unsigned long limit_pfn);
26static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
27static void free_iova_rcaches(struct iova_domain *iovad);
28
29unsigned long iova_rcache_range(void)
30{
31 return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1);
32}
33
34static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node)
35{
36 struct iova_domain *iovad;
37
38 iovad = hlist_entry_safe(node, struct iova_domain, cpuhp_dead);
39
40 free_cpu_cached_iovas(cpu, iovad);
41 return 0;
42}
43
44static void free_global_cached_iovas(struct iova_domain *iovad);
45
46static struct iova *to_iova(struct rb_node *node)
47{
48 return rb_entry(node, struct iova, node);
49}
50
51void
52init_iova_domain(struct iova_domain *iovad, unsigned long granule,
53 unsigned long start_pfn)
54{
55 /*
56 * IOVA granularity will normally be equal to the smallest
57 * supported IOMMU page size; both *must* be capable of
58 * representing individual CPU pages exactly.
59 */
60 BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
61
62 spin_lock_init(&iovad->iova_rbtree_lock);
63 iovad->rbroot = RB_ROOT;
64 iovad->cached_node = &iovad->anchor.node;
65 iovad->cached32_node = &iovad->anchor.node;
66 iovad->granule = granule;
67 iovad->start_pfn = start_pfn;
68 iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad));
69 iovad->max32_alloc_size = iovad->dma_32bit_pfn;
70 iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR;
71 rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node);
72 rb_insert_color(&iovad->anchor.node, &iovad->rbroot);
73}
74EXPORT_SYMBOL_GPL(init_iova_domain);
75
76static struct rb_node *
77__get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn)
78{
79 if (limit_pfn <= iovad->dma_32bit_pfn)
80 return iovad->cached32_node;
81
82 return iovad->cached_node;
83}
84
85static void
86__cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new)
87{
88 if (new->pfn_hi < iovad->dma_32bit_pfn)
89 iovad->cached32_node = &new->node;
90 else
91 iovad->cached_node = &new->node;
92}
93
94static void
95__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
96{
97 struct iova *cached_iova;
98
99 cached_iova = to_iova(iovad->cached32_node);
100 if (free == cached_iova ||
101 (free->pfn_hi < iovad->dma_32bit_pfn &&
102 free->pfn_lo >= cached_iova->pfn_lo))
103 iovad->cached32_node = rb_next(&free->node);
104
105 if (free->pfn_lo < iovad->dma_32bit_pfn)
106 iovad->max32_alloc_size = iovad->dma_32bit_pfn;
107
108 cached_iova = to_iova(iovad->cached_node);
109 if (free->pfn_lo >= cached_iova->pfn_lo)
110 iovad->cached_node = rb_next(&free->node);
111}
112
113static struct rb_node *iova_find_limit(struct iova_domain *iovad, unsigned long limit_pfn)
114{
115 struct rb_node *node, *next;
116 /*
117 * Ideally what we'd like to judge here is whether limit_pfn is close
118 * enough to the highest-allocated IOVA that starting the allocation
119 * walk from the anchor node will be quicker than this initial work to
120 * find an exact starting point (especially if that ends up being the
121 * anchor node anyway). This is an incredibly crude approximation which
122 * only really helps the most likely case, but is at least trivially easy.
123 */
124 if (limit_pfn > iovad->dma_32bit_pfn)
125 return &iovad->anchor.node;
126
127 node = iovad->rbroot.rb_node;
128 while (to_iova(node)->pfn_hi < limit_pfn)
129 node = node->rb_right;
130
131search_left:
132 while (node->rb_left && to_iova(node->rb_left)->pfn_lo >= limit_pfn)
133 node = node->rb_left;
134
135 if (!node->rb_left)
136 return node;
137
138 next = node->rb_left;
139 while (next->rb_right) {
140 next = next->rb_right;
141 if (to_iova(next)->pfn_lo >= limit_pfn) {
142 node = next;
143 goto search_left;
144 }
145 }
146
147 return node;
148}
149
150/* Insert the iova into domain rbtree by holding writer lock */
151static void
152iova_insert_rbtree(struct rb_root *root, struct iova *iova,
153 struct rb_node *start)
154{
155 struct rb_node **new, *parent = NULL;
156
157 new = (start) ? &start : &(root->rb_node);
158 /* Figure out where to put new node */
159 while (*new) {
160 struct iova *this = to_iova(*new);
161
162 parent = *new;
163
164 if (iova->pfn_lo < this->pfn_lo)
165 new = &((*new)->rb_left);
166 else if (iova->pfn_lo > this->pfn_lo)
167 new = &((*new)->rb_right);
168 else {
169 WARN_ON(1); /* this should not happen */
170 return;
171 }
172 }
173 /* Add new node and rebalance tree. */
174 rb_link_node(&iova->node, parent, new);
175 rb_insert_color(&iova->node, root);
176}
177
178static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
179 unsigned long size, unsigned long limit_pfn,
180 struct iova *new, bool size_aligned)
181{
182 struct rb_node *curr, *prev;
183 struct iova *curr_iova;
184 unsigned long flags;
185 unsigned long new_pfn, retry_pfn;
186 unsigned long align_mask = ~0UL;
187 unsigned long high_pfn = limit_pfn, low_pfn = iovad->start_pfn;
188
189 if (size_aligned)
190 align_mask <<= fls_long(size - 1);
191
192 /* Walk the tree backwards */
193 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
194 if (limit_pfn <= iovad->dma_32bit_pfn &&
195 size >= iovad->max32_alloc_size)
196 goto iova32_full;
197
198 curr = __get_cached_rbnode(iovad, limit_pfn);
199 curr_iova = to_iova(curr);
200 retry_pfn = curr_iova->pfn_hi;
201
202retry:
203 do {
204 high_pfn = min(high_pfn, curr_iova->pfn_lo);
205 new_pfn = (high_pfn - size) & align_mask;
206 prev = curr;
207 curr = rb_prev(curr);
208 curr_iova = to_iova(curr);
209 } while (curr && new_pfn <= curr_iova->pfn_hi && new_pfn >= low_pfn);
210
211 if (high_pfn < size || new_pfn < low_pfn) {
212 if (low_pfn == iovad->start_pfn && retry_pfn < limit_pfn) {
213 high_pfn = limit_pfn;
214 low_pfn = retry_pfn + 1;
215 curr = iova_find_limit(iovad, limit_pfn);
216 curr_iova = to_iova(curr);
217 goto retry;
218 }
219 iovad->max32_alloc_size = size;
220 goto iova32_full;
221 }
222
223 /* pfn_lo will point to size aligned address if size_aligned is set */
224 new->pfn_lo = new_pfn;
225 new->pfn_hi = new->pfn_lo + size - 1;
226
227 /* If we have 'prev', it's a valid place to start the insertion. */
228 iova_insert_rbtree(&iovad->rbroot, new, prev);
229 __cached_rbnode_insert_update(iovad, new);
230
231 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
232 return 0;
233
234iova32_full:
235 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
236 return -ENOMEM;
237}
238
239static struct kmem_cache *iova_cache;
240static unsigned int iova_cache_users;
241static DEFINE_MUTEX(iova_cache_mutex);
242
243static struct iova *alloc_iova_mem(void)
244{
245 return kmem_cache_zalloc(iova_cache, GFP_ATOMIC | __GFP_NOWARN);
246}
247
248static void free_iova_mem(struct iova *iova)
249{
250 if (iova->pfn_lo != IOVA_ANCHOR)
251 kmem_cache_free(iova_cache, iova);
252}
253
254int iova_cache_get(void)
255{
256 mutex_lock(&iova_cache_mutex);
257 if (!iova_cache_users) {
258 int ret;
259
260 ret = cpuhp_setup_state_multi(CPUHP_IOMMU_IOVA_DEAD, "iommu/iova:dead", NULL,
261 iova_cpuhp_dead);
262 if (ret) {
263 mutex_unlock(&iova_cache_mutex);
264 pr_err("Couldn't register cpuhp handler\n");
265 return ret;
266 }
267
268 iova_cache = kmem_cache_create(
269 "iommu_iova", sizeof(struct iova), 0,
270 SLAB_HWCACHE_ALIGN, NULL);
271 if (!iova_cache) {
272 cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD);
273 mutex_unlock(&iova_cache_mutex);
274 pr_err("Couldn't create iova cache\n");
275 return -ENOMEM;
276 }
277 }
278
279 iova_cache_users++;
280 mutex_unlock(&iova_cache_mutex);
281
282 return 0;
283}
284EXPORT_SYMBOL_GPL(iova_cache_get);
285
286void iova_cache_put(void)
287{
288 mutex_lock(&iova_cache_mutex);
289 if (WARN_ON(!iova_cache_users)) {
290 mutex_unlock(&iova_cache_mutex);
291 return;
292 }
293 iova_cache_users--;
294 if (!iova_cache_users) {
295 cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD);
296 kmem_cache_destroy(iova_cache);
297 }
298 mutex_unlock(&iova_cache_mutex);
299}
300EXPORT_SYMBOL_GPL(iova_cache_put);
301
302/**
303 * alloc_iova - allocates an iova
304 * @iovad: - iova domain in question
305 * @size: - size of page frames to allocate
306 * @limit_pfn: - max limit address
307 * @size_aligned: - set if size_aligned address range is required
308 * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
309 * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
310 * flag is set then the allocated address iova->pfn_lo will be naturally
311 * aligned on roundup_power_of_two(size).
312 */
313struct iova *
314alloc_iova(struct iova_domain *iovad, unsigned long size,
315 unsigned long limit_pfn,
316 bool size_aligned)
317{
318 struct iova *new_iova;
319 int ret;
320
321 new_iova = alloc_iova_mem();
322 if (!new_iova)
323 return NULL;
324
325 ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1,
326 new_iova, size_aligned);
327
328 if (ret) {
329 free_iova_mem(new_iova);
330 return NULL;
331 }
332
333 return new_iova;
334}
335EXPORT_SYMBOL_GPL(alloc_iova);
336
337static struct iova *
338private_find_iova(struct iova_domain *iovad, unsigned long pfn)
339{
340 struct rb_node *node = iovad->rbroot.rb_node;
341
342 assert_spin_locked(&iovad->iova_rbtree_lock);
343
344 while (node) {
345 struct iova *iova = to_iova(node);
346
347 if (pfn < iova->pfn_lo)
348 node = node->rb_left;
349 else if (pfn > iova->pfn_hi)
350 node = node->rb_right;
351 else
352 return iova; /* pfn falls within iova's range */
353 }
354
355 return NULL;
356}
357
358static void remove_iova(struct iova_domain *iovad, struct iova *iova)
359{
360 assert_spin_locked(&iovad->iova_rbtree_lock);
361 __cached_rbnode_delete_update(iovad, iova);
362 rb_erase(&iova->node, &iovad->rbroot);
363}
364
365/**
366 * find_iova - finds an iova for a given pfn
367 * @iovad: - iova domain in question.
368 * @pfn: - page frame number
369 * This function finds and returns an iova belonging to the
370 * given domain which matches the given pfn.
371 */
372struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
373{
374 unsigned long flags;
375 struct iova *iova;
376
377 /* Take the lock so that no other thread is manipulating the rbtree */
378 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
379 iova = private_find_iova(iovad, pfn);
380 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
381 return iova;
382}
383EXPORT_SYMBOL_GPL(find_iova);
384
385/**
386 * __free_iova - frees the given iova
387 * @iovad: iova domain in question.
388 * @iova: iova in question.
389 * Frees the given iova belonging to the giving domain
390 */
391void
392__free_iova(struct iova_domain *iovad, struct iova *iova)
393{
394 unsigned long flags;
395
396 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
397 remove_iova(iovad, iova);
398 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
399 free_iova_mem(iova);
400}
401EXPORT_SYMBOL_GPL(__free_iova);
402
403/**
404 * free_iova - finds and frees the iova for a given pfn
405 * @iovad: - iova domain in question.
406 * @pfn: - pfn that is allocated previously
407 * This functions finds an iova for a given pfn and then
408 * frees the iova from that domain.
409 */
410void
411free_iova(struct iova_domain *iovad, unsigned long pfn)
412{
413 unsigned long flags;
414 struct iova *iova;
415
416 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
417 iova = private_find_iova(iovad, pfn);
418 if (!iova) {
419 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
420 return;
421 }
422 remove_iova(iovad, iova);
423 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
424 free_iova_mem(iova);
425}
426EXPORT_SYMBOL_GPL(free_iova);
427
428/**
429 * alloc_iova_fast - allocates an iova from rcache
430 * @iovad: - iova domain in question
431 * @size: - size of page frames to allocate
432 * @limit_pfn: - max limit address
433 * @flush_rcache: - set to flush rcache on regular allocation failure
434 * This function tries to satisfy an iova allocation from the rcache,
435 * and falls back to regular allocation on failure. If regular allocation
436 * fails too and the flush_rcache flag is set then the rcache will be flushed.
437*/
438unsigned long
439alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
440 unsigned long limit_pfn, bool flush_rcache)
441{
442 unsigned long iova_pfn;
443 struct iova *new_iova;
444
445 /*
446 * Freeing non-power-of-two-sized allocations back into the IOVA caches
447 * will come back to bite us badly, so we have to waste a bit of space
448 * rounding up anything cacheable to make sure that can't happen. The
449 * order of the unadjusted size will still match upon freeing.
450 */
451 if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
452 size = roundup_pow_of_two(size);
453
454 iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
455 if (iova_pfn)
456 return iova_pfn;
457
458retry:
459 new_iova = alloc_iova(iovad, size, limit_pfn, true);
460 if (!new_iova) {
461 unsigned int cpu;
462
463 if (!flush_rcache)
464 return 0;
465
466 /* Try replenishing IOVAs by flushing rcache. */
467 flush_rcache = false;
468 for_each_online_cpu(cpu)
469 free_cpu_cached_iovas(cpu, iovad);
470 free_global_cached_iovas(iovad);
471 goto retry;
472 }
473
474 return new_iova->pfn_lo;
475}
476EXPORT_SYMBOL_GPL(alloc_iova_fast);
477
478/**
479 * free_iova_fast - free iova pfn range into rcache
480 * @iovad: - iova domain in question.
481 * @pfn: - pfn that is allocated previously
482 * @size: - # of pages in range
483 * This functions frees an iova range by trying to put it into the rcache,
484 * falling back to regular iova deallocation via free_iova() if this fails.
485 */
486void
487free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
488{
489 if (iova_rcache_insert(iovad, pfn, size))
490 return;
491
492 free_iova(iovad, pfn);
493}
494EXPORT_SYMBOL_GPL(free_iova_fast);
495
496static void iova_domain_free_rcaches(struct iova_domain *iovad)
497{
498 cpuhp_state_remove_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD,
499 &iovad->cpuhp_dead);
500 free_iova_rcaches(iovad);
501}
502
503/**
504 * put_iova_domain - destroys the iova domain
505 * @iovad: - iova domain in question.
506 * All the iova's in that domain are destroyed.
507 */
508void put_iova_domain(struct iova_domain *iovad)
509{
510 struct iova *iova, *tmp;
511
512 if (iovad->rcaches)
513 iova_domain_free_rcaches(iovad);
514
515 rbtree_postorder_for_each_entry_safe(iova, tmp, &iovad->rbroot, node)
516 free_iova_mem(iova);
517}
518EXPORT_SYMBOL_GPL(put_iova_domain);
519
520static int
521__is_range_overlap(struct rb_node *node,
522 unsigned long pfn_lo, unsigned long pfn_hi)
523{
524 struct iova *iova = to_iova(node);
525
526 if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
527 return 1;
528 return 0;
529}
530
531static inline struct iova *
532alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi)
533{
534 struct iova *iova;
535
536 iova = alloc_iova_mem();
537 if (iova) {
538 iova->pfn_lo = pfn_lo;
539 iova->pfn_hi = pfn_hi;
540 }
541
542 return iova;
543}
544
545static struct iova *
546__insert_new_range(struct iova_domain *iovad,
547 unsigned long pfn_lo, unsigned long pfn_hi)
548{
549 struct iova *iova;
550
551 iova = alloc_and_init_iova(pfn_lo, pfn_hi);
552 if (iova)
553 iova_insert_rbtree(&iovad->rbroot, iova, NULL);
554
555 return iova;
556}
557
558static void
559__adjust_overlap_range(struct iova *iova,
560 unsigned long *pfn_lo, unsigned long *pfn_hi)
561{
562 if (*pfn_lo < iova->pfn_lo)
563 iova->pfn_lo = *pfn_lo;
564 if (*pfn_hi > iova->pfn_hi)
565 *pfn_lo = iova->pfn_hi + 1;
566}
567
568/**
569 * reserve_iova - reserves an iova in the given range
570 * @iovad: - iova domain pointer
571 * @pfn_lo: - lower page frame address
572 * @pfn_hi:- higher pfn adderss
573 * This function allocates reserves the address range from pfn_lo to pfn_hi so
574 * that this address is not dished out as part of alloc_iova.
575 */
576struct iova *
577reserve_iova(struct iova_domain *iovad,
578 unsigned long pfn_lo, unsigned long pfn_hi)
579{
580 struct rb_node *node;
581 unsigned long flags;
582 struct iova *iova;
583 unsigned int overlap = 0;
584
585 /* Don't allow nonsensical pfns */
586 if (WARN_ON((pfn_hi | pfn_lo) > (ULLONG_MAX >> iova_shift(iovad))))
587 return NULL;
588
589 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
590 for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
591 if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
592 iova = to_iova(node);
593 __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
594 if ((pfn_lo >= iova->pfn_lo) &&
595 (pfn_hi <= iova->pfn_hi))
596 goto finish;
597 overlap = 1;
598
599 } else if (overlap)
600 break;
601 }
602
603 /* We are here either because this is the first reserver node
604 * or need to insert remaining non overlap addr range
605 */
606 iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
607finish:
608
609 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
610 return iova;
611}
612EXPORT_SYMBOL_GPL(reserve_iova);
613
614/*
615 * Magazine caches for IOVA ranges. For an introduction to magazines,
616 * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab
617 * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams.
618 * For simplicity, we use a static magazine size and don't implement the
619 * dynamic size tuning described in the paper.
620 */
621
622/*
623 * As kmalloc's buffer size is fixed to power of 2, 127 is chosen to
624 * assure size of 'iova_magazine' to be 1024 bytes, so that no memory
625 * will be wasted.
626 */
627#define IOVA_MAG_SIZE 127
628#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
629
630struct iova_magazine {
631 unsigned long size;
632 unsigned long pfns[IOVA_MAG_SIZE];
633};
634
635struct iova_cpu_rcache {
636 spinlock_t lock;
637 struct iova_magazine *loaded;
638 struct iova_magazine *prev;
639};
640
641struct iova_rcache {
642 spinlock_t lock;
643 unsigned long depot_size;
644 struct iova_magazine *depot[MAX_GLOBAL_MAGS];
645 struct iova_cpu_rcache __percpu *cpu_rcaches;
646};
647
648static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
649{
650 return kzalloc(sizeof(struct iova_magazine), flags);
651}
652
653static void iova_magazine_free(struct iova_magazine *mag)
654{
655 kfree(mag);
656}
657
658static void
659iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
660{
661 unsigned long flags;
662 int i;
663
664 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
665
666 for (i = 0 ; i < mag->size; ++i) {
667 struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
668
669 if (WARN_ON(!iova))
670 continue;
671
672 remove_iova(iovad, iova);
673 free_iova_mem(iova);
674 }
675
676 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
677
678 mag->size = 0;
679}
680
681static bool iova_magazine_full(struct iova_magazine *mag)
682{
683 return mag->size == IOVA_MAG_SIZE;
684}
685
686static bool iova_magazine_empty(struct iova_magazine *mag)
687{
688 return mag->size == 0;
689}
690
691static unsigned long iova_magazine_pop(struct iova_magazine *mag,
692 unsigned long limit_pfn)
693{
694 int i;
695 unsigned long pfn;
696
697 /* Only fall back to the rbtree if we have no suitable pfns at all */
698 for (i = mag->size - 1; mag->pfns[i] > limit_pfn; i--)
699 if (i == 0)
700 return 0;
701
702 /* Swap it to pop it */
703 pfn = mag->pfns[i];
704 mag->pfns[i] = mag->pfns[--mag->size];
705
706 return pfn;
707}
708
709static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
710{
711 mag->pfns[mag->size++] = pfn;
712}
713
714int iova_domain_init_rcaches(struct iova_domain *iovad)
715{
716 unsigned int cpu;
717 int i, ret;
718
719 iovad->rcaches = kcalloc(IOVA_RANGE_CACHE_MAX_SIZE,
720 sizeof(struct iova_rcache),
721 GFP_KERNEL);
722 if (!iovad->rcaches)
723 return -ENOMEM;
724
725 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
726 struct iova_cpu_rcache *cpu_rcache;
727 struct iova_rcache *rcache;
728
729 rcache = &iovad->rcaches[i];
730 spin_lock_init(&rcache->lock);
731 rcache->depot_size = 0;
732 rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache),
733 cache_line_size());
734 if (!rcache->cpu_rcaches) {
735 ret = -ENOMEM;
736 goto out_err;
737 }
738 for_each_possible_cpu(cpu) {
739 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
740
741 spin_lock_init(&cpu_rcache->lock);
742 cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
743 cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
744 if (!cpu_rcache->loaded || !cpu_rcache->prev) {
745 ret = -ENOMEM;
746 goto out_err;
747 }
748 }
749 }
750
751 ret = cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD,
752 &iovad->cpuhp_dead);
753 if (ret)
754 goto out_err;
755 return 0;
756
757out_err:
758 free_iova_rcaches(iovad);
759 return ret;
760}
761EXPORT_SYMBOL_GPL(iova_domain_init_rcaches);
762
763/*
764 * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
765 * return true on success. Can fail if rcache is full and we can't free
766 * space, and free_iova() (our only caller) will then return the IOVA
767 * range to the rbtree instead.
768 */
769static bool __iova_rcache_insert(struct iova_domain *iovad,
770 struct iova_rcache *rcache,
771 unsigned long iova_pfn)
772{
773 struct iova_magazine *mag_to_free = NULL;
774 struct iova_cpu_rcache *cpu_rcache;
775 bool can_insert = false;
776 unsigned long flags;
777
778 cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches);
779 spin_lock_irqsave(&cpu_rcache->lock, flags);
780
781 if (!iova_magazine_full(cpu_rcache->loaded)) {
782 can_insert = true;
783 } else if (!iova_magazine_full(cpu_rcache->prev)) {
784 swap(cpu_rcache->prev, cpu_rcache->loaded);
785 can_insert = true;
786 } else {
787 struct iova_magazine *new_mag = iova_magazine_alloc(GFP_ATOMIC);
788
789 if (new_mag) {
790 spin_lock(&rcache->lock);
791 if (rcache->depot_size < MAX_GLOBAL_MAGS) {
792 rcache->depot[rcache->depot_size++] =
793 cpu_rcache->loaded;
794 } else {
795 mag_to_free = cpu_rcache->loaded;
796 }
797 spin_unlock(&rcache->lock);
798
799 cpu_rcache->loaded = new_mag;
800 can_insert = true;
801 }
802 }
803
804 if (can_insert)
805 iova_magazine_push(cpu_rcache->loaded, iova_pfn);
806
807 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
808
809 if (mag_to_free) {
810 iova_magazine_free_pfns(mag_to_free, iovad);
811 iova_magazine_free(mag_to_free);
812 }
813
814 return can_insert;
815}
816
817static bool iova_rcache_insert(struct iova_domain *iovad, unsigned long pfn,
818 unsigned long size)
819{
820 unsigned int log_size = order_base_2(size);
821
822 if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
823 return false;
824
825 return __iova_rcache_insert(iovad, &iovad->rcaches[log_size], pfn);
826}
827
828/*
829 * Caller wants to allocate a new IOVA range from 'rcache'. If we can
830 * satisfy the request, return a matching non-NULL range and remove
831 * it from the 'rcache'.
832 */
833static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
834 unsigned long limit_pfn)
835{
836 struct iova_cpu_rcache *cpu_rcache;
837 unsigned long iova_pfn = 0;
838 bool has_pfn = false;
839 unsigned long flags;
840
841 cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches);
842 spin_lock_irqsave(&cpu_rcache->lock, flags);
843
844 if (!iova_magazine_empty(cpu_rcache->loaded)) {
845 has_pfn = true;
846 } else if (!iova_magazine_empty(cpu_rcache->prev)) {
847 swap(cpu_rcache->prev, cpu_rcache->loaded);
848 has_pfn = true;
849 } else {
850 spin_lock(&rcache->lock);
851 if (rcache->depot_size > 0) {
852 iova_magazine_free(cpu_rcache->loaded);
853 cpu_rcache->loaded = rcache->depot[--rcache->depot_size];
854 has_pfn = true;
855 }
856 spin_unlock(&rcache->lock);
857 }
858
859 if (has_pfn)
860 iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn);
861
862 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
863
864 return iova_pfn;
865}
866
867/*
868 * Try to satisfy IOVA allocation range from rcache. Fail if requested
869 * size is too big or the DMA limit we are given isn't satisfied by the
870 * top element in the magazine.
871 */
872static unsigned long iova_rcache_get(struct iova_domain *iovad,
873 unsigned long size,
874 unsigned long limit_pfn)
875{
876 unsigned int log_size = order_base_2(size);
877
878 if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
879 return 0;
880
881 return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
882}
883
884/*
885 * free rcache data structures.
886 */
887static void free_iova_rcaches(struct iova_domain *iovad)
888{
889 struct iova_rcache *rcache;
890 struct iova_cpu_rcache *cpu_rcache;
891 unsigned int cpu;
892 int i, j;
893
894 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
895 rcache = &iovad->rcaches[i];
896 if (!rcache->cpu_rcaches)
897 break;
898 for_each_possible_cpu(cpu) {
899 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
900 iova_magazine_free(cpu_rcache->loaded);
901 iova_magazine_free(cpu_rcache->prev);
902 }
903 free_percpu(rcache->cpu_rcaches);
904 for (j = 0; j < rcache->depot_size; ++j)
905 iova_magazine_free(rcache->depot[j]);
906 }
907
908 kfree(iovad->rcaches);
909 iovad->rcaches = NULL;
910}
911
912/*
913 * free all the IOVA ranges cached by a cpu (used when cpu is unplugged)
914 */
915static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
916{
917 struct iova_cpu_rcache *cpu_rcache;
918 struct iova_rcache *rcache;
919 unsigned long flags;
920 int i;
921
922 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
923 rcache = &iovad->rcaches[i];
924 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
925 spin_lock_irqsave(&cpu_rcache->lock, flags);
926 iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
927 iova_magazine_free_pfns(cpu_rcache->prev, iovad);
928 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
929 }
930}
931
932/*
933 * free all the IOVA ranges of global cache
934 */
935static void free_global_cached_iovas(struct iova_domain *iovad)
936{
937 struct iova_rcache *rcache;
938 unsigned long flags;
939 int i, j;
940
941 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
942 rcache = &iovad->rcaches[i];
943 spin_lock_irqsave(&rcache->lock, flags);
944 for (j = 0; j < rcache->depot_size; ++j) {
945 iova_magazine_free_pfns(rcache->depot[j], iovad);
946 iova_magazine_free(rcache->depot[j]);
947 }
948 rcache->depot_size = 0;
949 spin_unlock_irqrestore(&rcache->lock, flags);
950 }
951}
952MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
953MODULE_LICENSE("GPL");
1/*
2 * Copyright © 2006-2009, Intel Corporation.
3 *
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.
16 *
17 * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
18 */
19
20#include <linux/iova.h>
21#include <linux/module.h>
22#include <linux/slab.h>
23
24void
25init_iova_domain(struct iova_domain *iovad, unsigned long granule,
26 unsigned long start_pfn, unsigned long pfn_32bit)
27{
28 /*
29 * IOVA granularity will normally be equal to the smallest
30 * supported IOMMU page size; both *must* be capable of
31 * representing individual CPU pages exactly.
32 */
33 BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
34
35 spin_lock_init(&iovad->iova_rbtree_lock);
36 iovad->rbroot = RB_ROOT;
37 iovad->cached32_node = NULL;
38 iovad->granule = granule;
39 iovad->start_pfn = start_pfn;
40 iovad->dma_32bit_pfn = pfn_32bit;
41}
42EXPORT_SYMBOL_GPL(init_iova_domain);
43
44static struct rb_node *
45__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
46{
47 if ((*limit_pfn != iovad->dma_32bit_pfn) ||
48 (iovad->cached32_node == NULL))
49 return rb_last(&iovad->rbroot);
50 else {
51 struct rb_node *prev_node = rb_prev(iovad->cached32_node);
52 struct iova *curr_iova =
53 container_of(iovad->cached32_node, struct iova, node);
54 *limit_pfn = curr_iova->pfn_lo - 1;
55 return prev_node;
56 }
57}
58
59static void
60__cached_rbnode_insert_update(struct iova_domain *iovad,
61 unsigned long limit_pfn, struct iova *new)
62{
63 if (limit_pfn != iovad->dma_32bit_pfn)
64 return;
65 iovad->cached32_node = &new->node;
66}
67
68static void
69__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
70{
71 struct iova *cached_iova;
72 struct rb_node *curr;
73
74 if (!iovad->cached32_node)
75 return;
76 curr = iovad->cached32_node;
77 cached_iova = container_of(curr, struct iova, node);
78
79 if (free->pfn_lo >= cached_iova->pfn_lo) {
80 struct rb_node *node = rb_next(&free->node);
81 struct iova *iova = container_of(node, struct iova, node);
82
83 /* only cache if it's below 32bit pfn */
84 if (node && iova->pfn_lo < iovad->dma_32bit_pfn)
85 iovad->cached32_node = node;
86 else
87 iovad->cached32_node = NULL;
88 }
89}
90
91/*
92 * Computes the padding size required, to make the start address
93 * naturally aligned on the power-of-two order of its size
94 */
95static unsigned int
96iova_get_pad_size(unsigned int size, unsigned int limit_pfn)
97{
98 return (limit_pfn + 1 - size) & (__roundup_pow_of_two(size) - 1);
99}
100
101static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
102 unsigned long size, unsigned long limit_pfn,
103 struct iova *new, bool size_aligned)
104{
105 struct rb_node *prev, *curr = NULL;
106 unsigned long flags;
107 unsigned long saved_pfn;
108 unsigned int pad_size = 0;
109
110 /* Walk the tree backwards */
111 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
112 saved_pfn = limit_pfn;
113 curr = __get_cached_rbnode(iovad, &limit_pfn);
114 prev = curr;
115 while (curr) {
116 struct iova *curr_iova = container_of(curr, struct iova, node);
117
118 if (limit_pfn < curr_iova->pfn_lo)
119 goto move_left;
120 else if (limit_pfn < curr_iova->pfn_hi)
121 goto adjust_limit_pfn;
122 else {
123 if (size_aligned)
124 pad_size = iova_get_pad_size(size, limit_pfn);
125 if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn)
126 break; /* found a free slot */
127 }
128adjust_limit_pfn:
129 limit_pfn = curr_iova->pfn_lo - 1;
130move_left:
131 prev = curr;
132 curr = rb_prev(curr);
133 }
134
135 if (!curr) {
136 if (size_aligned)
137 pad_size = iova_get_pad_size(size, limit_pfn);
138 if ((iovad->start_pfn + size + pad_size) > limit_pfn) {
139 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
140 return -ENOMEM;
141 }
142 }
143
144 /* pfn_lo will point to size aligned address if size_aligned is set */
145 new->pfn_lo = limit_pfn - (size + pad_size) + 1;
146 new->pfn_hi = new->pfn_lo + size - 1;
147
148 /* Insert the new_iova into domain rbtree by holding writer lock */
149 /* Add new node and rebalance tree. */
150 {
151 struct rb_node **entry, *parent = NULL;
152
153 /* If we have 'prev', it's a valid place to start the
154 insertion. Otherwise, start from the root. */
155 if (prev)
156 entry = &prev;
157 else
158 entry = &iovad->rbroot.rb_node;
159
160 /* Figure out where to put new node */
161 while (*entry) {
162 struct iova *this = container_of(*entry,
163 struct iova, node);
164 parent = *entry;
165
166 if (new->pfn_lo < this->pfn_lo)
167 entry = &((*entry)->rb_left);
168 else if (new->pfn_lo > this->pfn_lo)
169 entry = &((*entry)->rb_right);
170 else
171 BUG(); /* this should not happen */
172 }
173
174 /* Add new node and rebalance tree. */
175 rb_link_node(&new->node, parent, entry);
176 rb_insert_color(&new->node, &iovad->rbroot);
177 }
178 __cached_rbnode_insert_update(iovad, saved_pfn, new);
179
180 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
181
182
183 return 0;
184}
185
186static void
187iova_insert_rbtree(struct rb_root *root, struct iova *iova)
188{
189 struct rb_node **new = &(root->rb_node), *parent = NULL;
190 /* Figure out where to put new node */
191 while (*new) {
192 struct iova *this = container_of(*new, struct iova, node);
193
194 parent = *new;
195
196 if (iova->pfn_lo < this->pfn_lo)
197 new = &((*new)->rb_left);
198 else if (iova->pfn_lo > this->pfn_lo)
199 new = &((*new)->rb_right);
200 else
201 BUG(); /* this should not happen */
202 }
203 /* Add new node and rebalance tree. */
204 rb_link_node(&iova->node, parent, new);
205 rb_insert_color(&iova->node, root);
206}
207
208static struct kmem_cache *iova_cache;
209static unsigned int iova_cache_users;
210static DEFINE_MUTEX(iova_cache_mutex);
211
212struct iova *alloc_iova_mem(void)
213{
214 return kmem_cache_alloc(iova_cache, GFP_ATOMIC);
215}
216EXPORT_SYMBOL(alloc_iova_mem);
217
218void free_iova_mem(struct iova *iova)
219{
220 kmem_cache_free(iova_cache, iova);
221}
222EXPORT_SYMBOL(free_iova_mem);
223
224int iova_cache_get(void)
225{
226 mutex_lock(&iova_cache_mutex);
227 if (!iova_cache_users) {
228 iova_cache = kmem_cache_create(
229 "iommu_iova", sizeof(struct iova), 0,
230 SLAB_HWCACHE_ALIGN, NULL);
231 if (!iova_cache) {
232 mutex_unlock(&iova_cache_mutex);
233 printk(KERN_ERR "Couldn't create iova cache\n");
234 return -ENOMEM;
235 }
236 }
237
238 iova_cache_users++;
239 mutex_unlock(&iova_cache_mutex);
240
241 return 0;
242}
243EXPORT_SYMBOL_GPL(iova_cache_get);
244
245void iova_cache_put(void)
246{
247 mutex_lock(&iova_cache_mutex);
248 if (WARN_ON(!iova_cache_users)) {
249 mutex_unlock(&iova_cache_mutex);
250 return;
251 }
252 iova_cache_users--;
253 if (!iova_cache_users)
254 kmem_cache_destroy(iova_cache);
255 mutex_unlock(&iova_cache_mutex);
256}
257EXPORT_SYMBOL_GPL(iova_cache_put);
258
259/**
260 * alloc_iova - allocates an iova
261 * @iovad: - iova domain in question
262 * @size: - size of page frames to allocate
263 * @limit_pfn: - max limit address
264 * @size_aligned: - set if size_aligned address range is required
265 * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
266 * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
267 * flag is set then the allocated address iova->pfn_lo will be naturally
268 * aligned on roundup_power_of_two(size).
269 */
270struct iova *
271alloc_iova(struct iova_domain *iovad, unsigned long size,
272 unsigned long limit_pfn,
273 bool size_aligned)
274{
275 struct iova *new_iova;
276 int ret;
277
278 new_iova = alloc_iova_mem();
279 if (!new_iova)
280 return NULL;
281
282 ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn,
283 new_iova, size_aligned);
284
285 if (ret) {
286 free_iova_mem(new_iova);
287 return NULL;
288 }
289
290 return new_iova;
291}
292EXPORT_SYMBOL_GPL(alloc_iova);
293
294/**
295 * find_iova - find's an iova for a given pfn
296 * @iovad: - iova domain in question.
297 * @pfn: - page frame number
298 * This function finds and returns an iova belonging to the
299 * given doamin which matches the given pfn.
300 */
301struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
302{
303 unsigned long flags;
304 struct rb_node *node;
305
306 /* Take the lock so that no other thread is manipulating the rbtree */
307 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
308 node = iovad->rbroot.rb_node;
309 while (node) {
310 struct iova *iova = container_of(node, struct iova, node);
311
312 /* If pfn falls within iova's range, return iova */
313 if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
314 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
315 /* We are not holding the lock while this iova
316 * is referenced by the caller as the same thread
317 * which called this function also calls __free_iova()
318 * and it is by design that only one thread can possibly
319 * reference a particular iova and hence no conflict.
320 */
321 return iova;
322 }
323
324 if (pfn < iova->pfn_lo)
325 node = node->rb_left;
326 else if (pfn > iova->pfn_lo)
327 node = node->rb_right;
328 }
329
330 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
331 return NULL;
332}
333EXPORT_SYMBOL_GPL(find_iova);
334
335/**
336 * __free_iova - frees the given iova
337 * @iovad: iova domain in question.
338 * @iova: iova in question.
339 * Frees the given iova belonging to the giving domain
340 */
341void
342__free_iova(struct iova_domain *iovad, struct iova *iova)
343{
344 unsigned long flags;
345
346 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
347 __cached_rbnode_delete_update(iovad, iova);
348 rb_erase(&iova->node, &iovad->rbroot);
349 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
350 free_iova_mem(iova);
351}
352EXPORT_SYMBOL_GPL(__free_iova);
353
354/**
355 * free_iova - finds and frees the iova for a given pfn
356 * @iovad: - iova domain in question.
357 * @pfn: - pfn that is allocated previously
358 * This functions finds an iova for a given pfn and then
359 * frees the iova from that domain.
360 */
361void
362free_iova(struct iova_domain *iovad, unsigned long pfn)
363{
364 struct iova *iova = find_iova(iovad, pfn);
365
366 if (iova)
367 __free_iova(iovad, iova);
368
369}
370EXPORT_SYMBOL_GPL(free_iova);
371
372/**
373 * put_iova_domain - destroys the iova doamin
374 * @iovad: - iova domain in question.
375 * All the iova's in that domain are destroyed.
376 */
377void put_iova_domain(struct iova_domain *iovad)
378{
379 struct rb_node *node;
380 unsigned long flags;
381
382 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
383 node = rb_first(&iovad->rbroot);
384 while (node) {
385 struct iova *iova = container_of(node, struct iova, node);
386
387 rb_erase(node, &iovad->rbroot);
388 free_iova_mem(iova);
389 node = rb_first(&iovad->rbroot);
390 }
391 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
392}
393EXPORT_SYMBOL_GPL(put_iova_domain);
394
395static int
396__is_range_overlap(struct rb_node *node,
397 unsigned long pfn_lo, unsigned long pfn_hi)
398{
399 struct iova *iova = container_of(node, struct iova, node);
400
401 if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
402 return 1;
403 return 0;
404}
405
406static inline struct iova *
407alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi)
408{
409 struct iova *iova;
410
411 iova = alloc_iova_mem();
412 if (iova) {
413 iova->pfn_lo = pfn_lo;
414 iova->pfn_hi = pfn_hi;
415 }
416
417 return iova;
418}
419
420static struct iova *
421__insert_new_range(struct iova_domain *iovad,
422 unsigned long pfn_lo, unsigned long pfn_hi)
423{
424 struct iova *iova;
425
426 iova = alloc_and_init_iova(pfn_lo, pfn_hi);
427 if (iova)
428 iova_insert_rbtree(&iovad->rbroot, iova);
429
430 return iova;
431}
432
433static void
434__adjust_overlap_range(struct iova *iova,
435 unsigned long *pfn_lo, unsigned long *pfn_hi)
436{
437 if (*pfn_lo < iova->pfn_lo)
438 iova->pfn_lo = *pfn_lo;
439 if (*pfn_hi > iova->pfn_hi)
440 *pfn_lo = iova->pfn_hi + 1;
441}
442
443/**
444 * reserve_iova - reserves an iova in the given range
445 * @iovad: - iova domain pointer
446 * @pfn_lo: - lower page frame address
447 * @pfn_hi:- higher pfn adderss
448 * This function allocates reserves the address range from pfn_lo to pfn_hi so
449 * that this address is not dished out as part of alloc_iova.
450 */
451struct iova *
452reserve_iova(struct iova_domain *iovad,
453 unsigned long pfn_lo, unsigned long pfn_hi)
454{
455 struct rb_node *node;
456 unsigned long flags;
457 struct iova *iova;
458 unsigned int overlap = 0;
459
460 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
461 for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
462 if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
463 iova = container_of(node, struct iova, node);
464 __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
465 if ((pfn_lo >= iova->pfn_lo) &&
466 (pfn_hi <= iova->pfn_hi))
467 goto finish;
468 overlap = 1;
469
470 } else if (overlap)
471 break;
472 }
473
474 /* We are here either because this is the first reserver node
475 * or need to insert remaining non overlap addr range
476 */
477 iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
478finish:
479
480 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
481 return iova;
482}
483EXPORT_SYMBOL_GPL(reserve_iova);
484
485/**
486 * copy_reserved_iova - copies the reserved between domains
487 * @from: - source doamin from where to copy
488 * @to: - destination domin where to copy
489 * This function copies reserved iova's from one doamin to
490 * other.
491 */
492void
493copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
494{
495 unsigned long flags;
496 struct rb_node *node;
497
498 spin_lock_irqsave(&from->iova_rbtree_lock, flags);
499 for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
500 struct iova *iova = container_of(node, struct iova, node);
501 struct iova *new_iova;
502
503 new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
504 if (!new_iova)
505 printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
506 iova->pfn_lo, iova->pfn_lo);
507 }
508 spin_unlock_irqrestore(&from->iova_rbtree_lock, flags);
509}
510EXPORT_SYMBOL_GPL(copy_reserved_iova);
511
512struct iova *
513split_and_remove_iova(struct iova_domain *iovad, struct iova *iova,
514 unsigned long pfn_lo, unsigned long pfn_hi)
515{
516 unsigned long flags;
517 struct iova *prev = NULL, *next = NULL;
518
519 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
520 if (iova->pfn_lo < pfn_lo) {
521 prev = alloc_and_init_iova(iova->pfn_lo, pfn_lo - 1);
522 if (prev == NULL)
523 goto error;
524 }
525 if (iova->pfn_hi > pfn_hi) {
526 next = alloc_and_init_iova(pfn_hi + 1, iova->pfn_hi);
527 if (next == NULL)
528 goto error;
529 }
530
531 __cached_rbnode_delete_update(iovad, iova);
532 rb_erase(&iova->node, &iovad->rbroot);
533
534 if (prev) {
535 iova_insert_rbtree(&iovad->rbroot, prev);
536 iova->pfn_lo = pfn_lo;
537 }
538 if (next) {
539 iova_insert_rbtree(&iovad->rbroot, next);
540 iova->pfn_hi = pfn_hi;
541 }
542 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
543
544 return iova;
545
546error:
547 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
548 if (prev)
549 free_iova_mem(prev);
550 return NULL;
551}
552
553MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
554MODULE_LICENSE("GPL");