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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
18static bool iova_rcache_insert(struct iova_domain *iovad,
19 unsigned long pfn,
20 unsigned long size);
21static unsigned long iova_rcache_get(struct iova_domain *iovad,
22 unsigned long size,
23 unsigned long limit_pfn);
24static void init_iova_rcaches(struct iova_domain *iovad);
25static void free_iova_rcaches(struct iova_domain *iovad);
26static void fq_destroy_all_entries(struct iova_domain *iovad);
27static void fq_flush_timeout(struct timer_list *t);
28
29void
30init_iova_domain(struct iova_domain *iovad, unsigned long granule,
31 unsigned long start_pfn)
32{
33 /*
34 * IOVA granularity will normally be equal to the smallest
35 * supported IOMMU page size; both *must* be capable of
36 * representing individual CPU pages exactly.
37 */
38 BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
39
40 spin_lock_init(&iovad->iova_rbtree_lock);
41 iovad->rbroot = RB_ROOT;
42 iovad->cached_node = &iovad->anchor.node;
43 iovad->cached32_node = &iovad->anchor.node;
44 iovad->granule = granule;
45 iovad->start_pfn = start_pfn;
46 iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad));
47 iovad->max32_alloc_size = iovad->dma_32bit_pfn;
48 iovad->flush_cb = NULL;
49 iovad->fq = NULL;
50 iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR;
51 rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node);
52 rb_insert_color(&iovad->anchor.node, &iovad->rbroot);
53 init_iova_rcaches(iovad);
54}
55EXPORT_SYMBOL_GPL(init_iova_domain);
56
57bool has_iova_flush_queue(struct iova_domain *iovad)
58{
59 return !!iovad->fq;
60}
61
62static void free_iova_flush_queue(struct iova_domain *iovad)
63{
64 if (!has_iova_flush_queue(iovad))
65 return;
66
67 if (timer_pending(&iovad->fq_timer))
68 del_timer(&iovad->fq_timer);
69
70 fq_destroy_all_entries(iovad);
71
72 free_percpu(iovad->fq);
73
74 iovad->fq = NULL;
75 iovad->flush_cb = NULL;
76 iovad->entry_dtor = NULL;
77}
78
79int init_iova_flush_queue(struct iova_domain *iovad,
80 iova_flush_cb flush_cb, iova_entry_dtor entry_dtor)
81{
82 struct iova_fq __percpu *queue;
83 int cpu;
84
85 atomic64_set(&iovad->fq_flush_start_cnt, 0);
86 atomic64_set(&iovad->fq_flush_finish_cnt, 0);
87
88 queue = alloc_percpu(struct iova_fq);
89 if (!queue)
90 return -ENOMEM;
91
92 iovad->flush_cb = flush_cb;
93 iovad->entry_dtor = entry_dtor;
94
95 for_each_possible_cpu(cpu) {
96 struct iova_fq *fq;
97
98 fq = per_cpu_ptr(queue, cpu);
99 fq->head = 0;
100 fq->tail = 0;
101
102 spin_lock_init(&fq->lock);
103 }
104
105 smp_wmb();
106
107 iovad->fq = queue;
108
109 timer_setup(&iovad->fq_timer, fq_flush_timeout, 0);
110 atomic_set(&iovad->fq_timer_on, 0);
111
112 return 0;
113}
114EXPORT_SYMBOL_GPL(init_iova_flush_queue);
115
116static struct rb_node *
117__get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn)
118{
119 if (limit_pfn <= iovad->dma_32bit_pfn)
120 return iovad->cached32_node;
121
122 return iovad->cached_node;
123}
124
125static void
126__cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new)
127{
128 if (new->pfn_hi < iovad->dma_32bit_pfn)
129 iovad->cached32_node = &new->node;
130 else
131 iovad->cached_node = &new->node;
132}
133
134static void
135__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
136{
137 struct iova *cached_iova;
138
139 cached_iova = rb_entry(iovad->cached32_node, struct iova, node);
140 if (free == cached_iova ||
141 (free->pfn_hi < iovad->dma_32bit_pfn &&
142 free->pfn_lo >= cached_iova->pfn_lo)) {
143 iovad->cached32_node = rb_next(&free->node);
144 iovad->max32_alloc_size = iovad->dma_32bit_pfn;
145 }
146
147 cached_iova = rb_entry(iovad->cached_node, struct iova, node);
148 if (free->pfn_lo >= cached_iova->pfn_lo)
149 iovad->cached_node = rb_next(&free->node);
150}
151
152/* Insert the iova into domain rbtree by holding writer lock */
153static void
154iova_insert_rbtree(struct rb_root *root, struct iova *iova,
155 struct rb_node *start)
156{
157 struct rb_node **new, *parent = NULL;
158
159 new = (start) ? &start : &(root->rb_node);
160 /* Figure out where to put new node */
161 while (*new) {
162 struct iova *this = rb_entry(*new, struct iova, node);
163
164 parent = *new;
165
166 if (iova->pfn_lo < this->pfn_lo)
167 new = &((*new)->rb_left);
168 else if (iova->pfn_lo > this->pfn_lo)
169 new = &((*new)->rb_right);
170 else {
171 WARN_ON(1); /* this should not happen */
172 return;
173 }
174 }
175 /* Add new node and rebalance tree. */
176 rb_link_node(&iova->node, parent, new);
177 rb_insert_color(&iova->node, root);
178}
179
180static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
181 unsigned long size, unsigned long limit_pfn,
182 struct iova *new, bool size_aligned)
183{
184 struct rb_node *curr, *prev;
185 struct iova *curr_iova;
186 unsigned long flags;
187 unsigned long new_pfn;
188 unsigned long align_mask = ~0UL;
189
190 if (size_aligned)
191 align_mask <<= fls_long(size - 1);
192
193 /* Walk the tree backwards */
194 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
195 if (limit_pfn <= iovad->dma_32bit_pfn &&
196 size >= iovad->max32_alloc_size)
197 goto iova32_full;
198
199 curr = __get_cached_rbnode(iovad, limit_pfn);
200 curr_iova = rb_entry(curr, struct iova, node);
201 do {
202 limit_pfn = min(limit_pfn, curr_iova->pfn_lo);
203 new_pfn = (limit_pfn - size) & align_mask;
204 prev = curr;
205 curr = rb_prev(curr);
206 curr_iova = rb_entry(curr, struct iova, node);
207 } while (curr && new_pfn <= curr_iova->pfn_hi);
208
209 if (limit_pfn < size || new_pfn < iovad->start_pfn) {
210 iovad->max32_alloc_size = size;
211 goto iova32_full;
212 }
213
214 /* pfn_lo will point to size aligned address if size_aligned is set */
215 new->pfn_lo = new_pfn;
216 new->pfn_hi = new->pfn_lo + size - 1;
217
218 /* If we have 'prev', it's a valid place to start the insertion. */
219 iova_insert_rbtree(&iovad->rbroot, new, prev);
220 __cached_rbnode_insert_update(iovad, new);
221
222 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
223 return 0;
224
225iova32_full:
226 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
227 return -ENOMEM;
228}
229
230static struct kmem_cache *iova_cache;
231static unsigned int iova_cache_users;
232static DEFINE_MUTEX(iova_cache_mutex);
233
234struct iova *alloc_iova_mem(void)
235{
236 return kmem_cache_zalloc(iova_cache, GFP_ATOMIC | __GFP_NOWARN);
237}
238EXPORT_SYMBOL(alloc_iova_mem);
239
240void free_iova_mem(struct iova *iova)
241{
242 if (iova->pfn_lo != IOVA_ANCHOR)
243 kmem_cache_free(iova_cache, iova);
244}
245EXPORT_SYMBOL(free_iova_mem);
246
247int iova_cache_get(void)
248{
249 mutex_lock(&iova_cache_mutex);
250 if (!iova_cache_users) {
251 iova_cache = kmem_cache_create(
252 "iommu_iova", sizeof(struct iova), 0,
253 SLAB_HWCACHE_ALIGN, NULL);
254 if (!iova_cache) {
255 mutex_unlock(&iova_cache_mutex);
256 pr_err("Couldn't create iova cache\n");
257 return -ENOMEM;
258 }
259 }
260
261 iova_cache_users++;
262 mutex_unlock(&iova_cache_mutex);
263
264 return 0;
265}
266EXPORT_SYMBOL_GPL(iova_cache_get);
267
268void iova_cache_put(void)
269{
270 mutex_lock(&iova_cache_mutex);
271 if (WARN_ON(!iova_cache_users)) {
272 mutex_unlock(&iova_cache_mutex);
273 return;
274 }
275 iova_cache_users--;
276 if (!iova_cache_users)
277 kmem_cache_destroy(iova_cache);
278 mutex_unlock(&iova_cache_mutex);
279}
280EXPORT_SYMBOL_GPL(iova_cache_put);
281
282/**
283 * alloc_iova - allocates an iova
284 * @iovad: - iova domain in question
285 * @size: - size of page frames to allocate
286 * @limit_pfn: - max limit address
287 * @size_aligned: - set if size_aligned address range is required
288 * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
289 * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
290 * flag is set then the allocated address iova->pfn_lo will be naturally
291 * aligned on roundup_power_of_two(size).
292 */
293struct iova *
294alloc_iova(struct iova_domain *iovad, unsigned long size,
295 unsigned long limit_pfn,
296 bool size_aligned)
297{
298 struct iova *new_iova;
299 int ret;
300
301 new_iova = alloc_iova_mem();
302 if (!new_iova)
303 return NULL;
304
305 ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1,
306 new_iova, size_aligned);
307
308 if (ret) {
309 free_iova_mem(new_iova);
310 return NULL;
311 }
312
313 return new_iova;
314}
315EXPORT_SYMBOL_GPL(alloc_iova);
316
317static struct iova *
318private_find_iova(struct iova_domain *iovad, unsigned long pfn)
319{
320 struct rb_node *node = iovad->rbroot.rb_node;
321
322 assert_spin_locked(&iovad->iova_rbtree_lock);
323
324 while (node) {
325 struct iova *iova = rb_entry(node, struct iova, node);
326
327 if (pfn < iova->pfn_lo)
328 node = node->rb_left;
329 else if (pfn > iova->pfn_hi)
330 node = node->rb_right;
331 else
332 return iova; /* pfn falls within iova's range */
333 }
334
335 return NULL;
336}
337
338static void private_free_iova(struct iova_domain *iovad, struct iova *iova)
339{
340 assert_spin_locked(&iovad->iova_rbtree_lock);
341 __cached_rbnode_delete_update(iovad, iova);
342 rb_erase(&iova->node, &iovad->rbroot);
343 free_iova_mem(iova);
344}
345
346/**
347 * find_iova - finds an iova for a given pfn
348 * @iovad: - iova domain in question.
349 * @pfn: - page frame number
350 * This function finds and returns an iova belonging to the
351 * given doamin which matches the given pfn.
352 */
353struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
354{
355 unsigned long flags;
356 struct iova *iova;
357
358 /* Take the lock so that no other thread is manipulating the rbtree */
359 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
360 iova = private_find_iova(iovad, pfn);
361 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
362 return iova;
363}
364EXPORT_SYMBOL_GPL(find_iova);
365
366/**
367 * __free_iova - frees the given iova
368 * @iovad: iova domain in question.
369 * @iova: iova in question.
370 * Frees the given iova belonging to the giving domain
371 */
372void
373__free_iova(struct iova_domain *iovad, struct iova *iova)
374{
375 unsigned long flags;
376
377 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
378 private_free_iova(iovad, iova);
379 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
380}
381EXPORT_SYMBOL_GPL(__free_iova);
382
383/**
384 * free_iova - finds and frees the iova for a given pfn
385 * @iovad: - iova domain in question.
386 * @pfn: - pfn that is allocated previously
387 * This functions finds an iova for a given pfn and then
388 * frees the iova from that domain.
389 */
390void
391free_iova(struct iova_domain *iovad, unsigned long pfn)
392{
393 struct iova *iova = find_iova(iovad, pfn);
394
395 if (iova)
396 __free_iova(iovad, iova);
397
398}
399EXPORT_SYMBOL_GPL(free_iova);
400
401/**
402 * alloc_iova_fast - allocates an iova from rcache
403 * @iovad: - iova domain in question
404 * @size: - size of page frames to allocate
405 * @limit_pfn: - max limit address
406 * @flush_rcache: - set to flush rcache on regular allocation failure
407 * This function tries to satisfy an iova allocation from the rcache,
408 * and falls back to regular allocation on failure. If regular allocation
409 * fails too and the flush_rcache flag is set then the rcache will be flushed.
410*/
411unsigned long
412alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
413 unsigned long limit_pfn, bool flush_rcache)
414{
415 unsigned long iova_pfn;
416 struct iova *new_iova;
417
418 iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
419 if (iova_pfn)
420 return iova_pfn;
421
422retry:
423 new_iova = alloc_iova(iovad, size, limit_pfn, true);
424 if (!new_iova) {
425 unsigned int cpu;
426
427 if (!flush_rcache)
428 return 0;
429
430 /* Try replenishing IOVAs by flushing rcache. */
431 flush_rcache = false;
432 for_each_online_cpu(cpu)
433 free_cpu_cached_iovas(cpu, iovad);
434 goto retry;
435 }
436
437 return new_iova->pfn_lo;
438}
439EXPORT_SYMBOL_GPL(alloc_iova_fast);
440
441/**
442 * free_iova_fast - free iova pfn range into rcache
443 * @iovad: - iova domain in question.
444 * @pfn: - pfn that is allocated previously
445 * @size: - # of pages in range
446 * This functions frees an iova range by trying to put it into the rcache,
447 * falling back to regular iova deallocation via free_iova() if this fails.
448 */
449void
450free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
451{
452 if (iova_rcache_insert(iovad, pfn, size))
453 return;
454
455 free_iova(iovad, pfn);
456}
457EXPORT_SYMBOL_GPL(free_iova_fast);
458
459#define fq_ring_for_each(i, fq) \
460 for ((i) = (fq)->head; (i) != (fq)->tail; (i) = ((i) + 1) % IOVA_FQ_SIZE)
461
462static inline bool fq_full(struct iova_fq *fq)
463{
464 assert_spin_locked(&fq->lock);
465 return (((fq->tail + 1) % IOVA_FQ_SIZE) == fq->head);
466}
467
468static inline unsigned fq_ring_add(struct iova_fq *fq)
469{
470 unsigned idx = fq->tail;
471
472 assert_spin_locked(&fq->lock);
473
474 fq->tail = (idx + 1) % IOVA_FQ_SIZE;
475
476 return idx;
477}
478
479static void fq_ring_free(struct iova_domain *iovad, struct iova_fq *fq)
480{
481 u64 counter = atomic64_read(&iovad->fq_flush_finish_cnt);
482 unsigned idx;
483
484 assert_spin_locked(&fq->lock);
485
486 fq_ring_for_each(idx, fq) {
487
488 if (fq->entries[idx].counter >= counter)
489 break;
490
491 if (iovad->entry_dtor)
492 iovad->entry_dtor(fq->entries[idx].data);
493
494 free_iova_fast(iovad,
495 fq->entries[idx].iova_pfn,
496 fq->entries[idx].pages);
497
498 fq->head = (fq->head + 1) % IOVA_FQ_SIZE;
499 }
500}
501
502static void iova_domain_flush(struct iova_domain *iovad)
503{
504 atomic64_inc(&iovad->fq_flush_start_cnt);
505 iovad->flush_cb(iovad);
506 atomic64_inc(&iovad->fq_flush_finish_cnt);
507}
508
509static void fq_destroy_all_entries(struct iova_domain *iovad)
510{
511 int cpu;
512
513 /*
514 * This code runs when the iova_domain is being detroyed, so don't
515 * bother to free iovas, just call the entry_dtor on all remaining
516 * entries.
517 */
518 if (!iovad->entry_dtor)
519 return;
520
521 for_each_possible_cpu(cpu) {
522 struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu);
523 int idx;
524
525 fq_ring_for_each(idx, fq)
526 iovad->entry_dtor(fq->entries[idx].data);
527 }
528}
529
530static void fq_flush_timeout(struct timer_list *t)
531{
532 struct iova_domain *iovad = from_timer(iovad, t, fq_timer);
533 int cpu;
534
535 atomic_set(&iovad->fq_timer_on, 0);
536 iova_domain_flush(iovad);
537
538 for_each_possible_cpu(cpu) {
539 unsigned long flags;
540 struct iova_fq *fq;
541
542 fq = per_cpu_ptr(iovad->fq, cpu);
543 spin_lock_irqsave(&fq->lock, flags);
544 fq_ring_free(iovad, fq);
545 spin_unlock_irqrestore(&fq->lock, flags);
546 }
547}
548
549void queue_iova(struct iova_domain *iovad,
550 unsigned long pfn, unsigned long pages,
551 unsigned long data)
552{
553 struct iova_fq *fq = raw_cpu_ptr(iovad->fq);
554 unsigned long flags;
555 unsigned idx;
556
557 spin_lock_irqsave(&fq->lock, flags);
558
559 /*
560 * First remove all entries from the flush queue that have already been
561 * flushed out on another CPU. This makes the fq_full() check below less
562 * likely to be true.
563 */
564 fq_ring_free(iovad, fq);
565
566 if (fq_full(fq)) {
567 iova_domain_flush(iovad);
568 fq_ring_free(iovad, fq);
569 }
570
571 idx = fq_ring_add(fq);
572
573 fq->entries[idx].iova_pfn = pfn;
574 fq->entries[idx].pages = pages;
575 fq->entries[idx].data = data;
576 fq->entries[idx].counter = atomic64_read(&iovad->fq_flush_start_cnt);
577
578 spin_unlock_irqrestore(&fq->lock, flags);
579
580 /* Avoid false sharing as much as possible. */
581 if (!atomic_read(&iovad->fq_timer_on) &&
582 !atomic_cmpxchg(&iovad->fq_timer_on, 0, 1))
583 mod_timer(&iovad->fq_timer,
584 jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT));
585}
586EXPORT_SYMBOL_GPL(queue_iova);
587
588/**
589 * put_iova_domain - destroys the iova doamin
590 * @iovad: - iova domain in question.
591 * All the iova's in that domain are destroyed.
592 */
593void put_iova_domain(struct iova_domain *iovad)
594{
595 struct iova *iova, *tmp;
596
597 free_iova_flush_queue(iovad);
598 free_iova_rcaches(iovad);
599 rbtree_postorder_for_each_entry_safe(iova, tmp, &iovad->rbroot, node)
600 free_iova_mem(iova);
601}
602EXPORT_SYMBOL_GPL(put_iova_domain);
603
604static int
605__is_range_overlap(struct rb_node *node,
606 unsigned long pfn_lo, unsigned long pfn_hi)
607{
608 struct iova *iova = rb_entry(node, struct iova, node);
609
610 if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
611 return 1;
612 return 0;
613}
614
615static inline struct iova *
616alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi)
617{
618 struct iova *iova;
619
620 iova = alloc_iova_mem();
621 if (iova) {
622 iova->pfn_lo = pfn_lo;
623 iova->pfn_hi = pfn_hi;
624 }
625
626 return iova;
627}
628
629static struct iova *
630__insert_new_range(struct iova_domain *iovad,
631 unsigned long pfn_lo, unsigned long pfn_hi)
632{
633 struct iova *iova;
634
635 iova = alloc_and_init_iova(pfn_lo, pfn_hi);
636 if (iova)
637 iova_insert_rbtree(&iovad->rbroot, iova, NULL);
638
639 return iova;
640}
641
642static void
643__adjust_overlap_range(struct iova *iova,
644 unsigned long *pfn_lo, unsigned long *pfn_hi)
645{
646 if (*pfn_lo < iova->pfn_lo)
647 iova->pfn_lo = *pfn_lo;
648 if (*pfn_hi > iova->pfn_hi)
649 *pfn_lo = iova->pfn_hi + 1;
650}
651
652/**
653 * reserve_iova - reserves an iova in the given range
654 * @iovad: - iova domain pointer
655 * @pfn_lo: - lower page frame address
656 * @pfn_hi:- higher pfn adderss
657 * This function allocates reserves the address range from pfn_lo to pfn_hi so
658 * that this address is not dished out as part of alloc_iova.
659 */
660struct iova *
661reserve_iova(struct iova_domain *iovad,
662 unsigned long pfn_lo, unsigned long pfn_hi)
663{
664 struct rb_node *node;
665 unsigned long flags;
666 struct iova *iova;
667 unsigned int overlap = 0;
668
669 /* Don't allow nonsensical pfns */
670 if (WARN_ON((pfn_hi | pfn_lo) > (ULLONG_MAX >> iova_shift(iovad))))
671 return NULL;
672
673 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
674 for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
675 if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
676 iova = rb_entry(node, struct iova, node);
677 __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
678 if ((pfn_lo >= iova->pfn_lo) &&
679 (pfn_hi <= iova->pfn_hi))
680 goto finish;
681 overlap = 1;
682
683 } else if (overlap)
684 break;
685 }
686
687 /* We are here either because this is the first reserver node
688 * or need to insert remaining non overlap addr range
689 */
690 iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
691finish:
692
693 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
694 return iova;
695}
696EXPORT_SYMBOL_GPL(reserve_iova);
697
698/**
699 * copy_reserved_iova - copies the reserved between domains
700 * @from: - source doamin from where to copy
701 * @to: - destination domin where to copy
702 * This function copies reserved iova's from one doamin to
703 * other.
704 */
705void
706copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
707{
708 unsigned long flags;
709 struct rb_node *node;
710
711 spin_lock_irqsave(&from->iova_rbtree_lock, flags);
712 for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
713 struct iova *iova = rb_entry(node, struct iova, node);
714 struct iova *new_iova;
715
716 if (iova->pfn_lo == IOVA_ANCHOR)
717 continue;
718
719 new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
720 if (!new_iova)
721 pr_err("Reserve iova range %lx@%lx failed\n",
722 iova->pfn_lo, iova->pfn_lo);
723 }
724 spin_unlock_irqrestore(&from->iova_rbtree_lock, flags);
725}
726EXPORT_SYMBOL_GPL(copy_reserved_iova);
727
728struct iova *
729split_and_remove_iova(struct iova_domain *iovad, struct iova *iova,
730 unsigned long pfn_lo, unsigned long pfn_hi)
731{
732 unsigned long flags;
733 struct iova *prev = NULL, *next = NULL;
734
735 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
736 if (iova->pfn_lo < pfn_lo) {
737 prev = alloc_and_init_iova(iova->pfn_lo, pfn_lo - 1);
738 if (prev == NULL)
739 goto error;
740 }
741 if (iova->pfn_hi > pfn_hi) {
742 next = alloc_and_init_iova(pfn_hi + 1, iova->pfn_hi);
743 if (next == NULL)
744 goto error;
745 }
746
747 __cached_rbnode_delete_update(iovad, iova);
748 rb_erase(&iova->node, &iovad->rbroot);
749
750 if (prev) {
751 iova_insert_rbtree(&iovad->rbroot, prev, NULL);
752 iova->pfn_lo = pfn_lo;
753 }
754 if (next) {
755 iova_insert_rbtree(&iovad->rbroot, next, NULL);
756 iova->pfn_hi = pfn_hi;
757 }
758 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
759
760 return iova;
761
762error:
763 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
764 if (prev)
765 free_iova_mem(prev);
766 return NULL;
767}
768
769/*
770 * Magazine caches for IOVA ranges. For an introduction to magazines,
771 * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab
772 * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams.
773 * For simplicity, we use a static magazine size and don't implement the
774 * dynamic size tuning described in the paper.
775 */
776
777#define IOVA_MAG_SIZE 128
778
779struct iova_magazine {
780 unsigned long size;
781 unsigned long pfns[IOVA_MAG_SIZE];
782};
783
784struct iova_cpu_rcache {
785 spinlock_t lock;
786 struct iova_magazine *loaded;
787 struct iova_magazine *prev;
788};
789
790static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
791{
792 return kzalloc(sizeof(struct iova_magazine), flags);
793}
794
795static void iova_magazine_free(struct iova_magazine *mag)
796{
797 kfree(mag);
798}
799
800static void
801iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
802{
803 unsigned long flags;
804 int i;
805
806 if (!mag)
807 return;
808
809 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
810
811 for (i = 0 ; i < mag->size; ++i) {
812 struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
813
814 if (WARN_ON(!iova))
815 continue;
816
817 private_free_iova(iovad, iova);
818 }
819
820 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
821
822 mag->size = 0;
823}
824
825static bool iova_magazine_full(struct iova_magazine *mag)
826{
827 return (mag && mag->size == IOVA_MAG_SIZE);
828}
829
830static bool iova_magazine_empty(struct iova_magazine *mag)
831{
832 return (!mag || mag->size == 0);
833}
834
835static unsigned long iova_magazine_pop(struct iova_magazine *mag,
836 unsigned long limit_pfn)
837{
838 int i;
839 unsigned long pfn;
840
841 BUG_ON(iova_magazine_empty(mag));
842
843 /* Only fall back to the rbtree if we have no suitable pfns at all */
844 for (i = mag->size - 1; mag->pfns[i] > limit_pfn; i--)
845 if (i == 0)
846 return 0;
847
848 /* Swap it to pop it */
849 pfn = mag->pfns[i];
850 mag->pfns[i] = mag->pfns[--mag->size];
851
852 return pfn;
853}
854
855static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
856{
857 BUG_ON(iova_magazine_full(mag));
858
859 mag->pfns[mag->size++] = pfn;
860}
861
862static void init_iova_rcaches(struct iova_domain *iovad)
863{
864 struct iova_cpu_rcache *cpu_rcache;
865 struct iova_rcache *rcache;
866 unsigned int cpu;
867 int i;
868
869 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
870 rcache = &iovad->rcaches[i];
871 spin_lock_init(&rcache->lock);
872 rcache->depot_size = 0;
873 rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache), cache_line_size());
874 if (WARN_ON(!rcache->cpu_rcaches))
875 continue;
876 for_each_possible_cpu(cpu) {
877 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
878 spin_lock_init(&cpu_rcache->lock);
879 cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
880 cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
881 }
882 }
883}
884
885/*
886 * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
887 * return true on success. Can fail if rcache is full and we can't free
888 * space, and free_iova() (our only caller) will then return the IOVA
889 * range to the rbtree instead.
890 */
891static bool __iova_rcache_insert(struct iova_domain *iovad,
892 struct iova_rcache *rcache,
893 unsigned long iova_pfn)
894{
895 struct iova_magazine *mag_to_free = NULL;
896 struct iova_cpu_rcache *cpu_rcache;
897 bool can_insert = false;
898 unsigned long flags;
899
900 cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches);
901 spin_lock_irqsave(&cpu_rcache->lock, flags);
902
903 if (!iova_magazine_full(cpu_rcache->loaded)) {
904 can_insert = true;
905 } else if (!iova_magazine_full(cpu_rcache->prev)) {
906 swap(cpu_rcache->prev, cpu_rcache->loaded);
907 can_insert = true;
908 } else {
909 struct iova_magazine *new_mag = iova_magazine_alloc(GFP_ATOMIC);
910
911 if (new_mag) {
912 spin_lock(&rcache->lock);
913 if (rcache->depot_size < MAX_GLOBAL_MAGS) {
914 rcache->depot[rcache->depot_size++] =
915 cpu_rcache->loaded;
916 } else {
917 mag_to_free = cpu_rcache->loaded;
918 }
919 spin_unlock(&rcache->lock);
920
921 cpu_rcache->loaded = new_mag;
922 can_insert = true;
923 }
924 }
925
926 if (can_insert)
927 iova_magazine_push(cpu_rcache->loaded, iova_pfn);
928
929 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
930
931 if (mag_to_free) {
932 iova_magazine_free_pfns(mag_to_free, iovad);
933 iova_magazine_free(mag_to_free);
934 }
935
936 return can_insert;
937}
938
939static bool iova_rcache_insert(struct iova_domain *iovad, unsigned long pfn,
940 unsigned long size)
941{
942 unsigned int log_size = order_base_2(size);
943
944 if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
945 return false;
946
947 return __iova_rcache_insert(iovad, &iovad->rcaches[log_size], pfn);
948}
949
950/*
951 * Caller wants to allocate a new IOVA range from 'rcache'. If we can
952 * satisfy the request, return a matching non-NULL range and remove
953 * it from the 'rcache'.
954 */
955static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
956 unsigned long limit_pfn)
957{
958 struct iova_cpu_rcache *cpu_rcache;
959 unsigned long iova_pfn = 0;
960 bool has_pfn = false;
961 unsigned long flags;
962
963 cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches);
964 spin_lock_irqsave(&cpu_rcache->lock, flags);
965
966 if (!iova_magazine_empty(cpu_rcache->loaded)) {
967 has_pfn = true;
968 } else if (!iova_magazine_empty(cpu_rcache->prev)) {
969 swap(cpu_rcache->prev, cpu_rcache->loaded);
970 has_pfn = true;
971 } else {
972 spin_lock(&rcache->lock);
973 if (rcache->depot_size > 0) {
974 iova_magazine_free(cpu_rcache->loaded);
975 cpu_rcache->loaded = rcache->depot[--rcache->depot_size];
976 has_pfn = true;
977 }
978 spin_unlock(&rcache->lock);
979 }
980
981 if (has_pfn)
982 iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn);
983
984 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
985
986 return iova_pfn;
987}
988
989/*
990 * Try to satisfy IOVA allocation range from rcache. Fail if requested
991 * size is too big or the DMA limit we are given isn't satisfied by the
992 * top element in the magazine.
993 */
994static unsigned long iova_rcache_get(struct iova_domain *iovad,
995 unsigned long size,
996 unsigned long limit_pfn)
997{
998 unsigned int log_size = order_base_2(size);
999
1000 if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
1001 return 0;
1002
1003 return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
1004}
1005
1006/*
1007 * free rcache data structures.
1008 */
1009static void free_iova_rcaches(struct iova_domain *iovad)
1010{
1011 struct iova_rcache *rcache;
1012 struct iova_cpu_rcache *cpu_rcache;
1013 unsigned int cpu;
1014 int i, j;
1015
1016 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
1017 rcache = &iovad->rcaches[i];
1018 for_each_possible_cpu(cpu) {
1019 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
1020 iova_magazine_free(cpu_rcache->loaded);
1021 iova_magazine_free(cpu_rcache->prev);
1022 }
1023 free_percpu(rcache->cpu_rcaches);
1024 for (j = 0; j < rcache->depot_size; ++j)
1025 iova_magazine_free(rcache->depot[j]);
1026 }
1027}
1028
1029/*
1030 * free all the IOVA ranges cached by a cpu (used when cpu is unplugged)
1031 */
1032void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
1033{
1034 struct iova_cpu_rcache *cpu_rcache;
1035 struct iova_rcache *rcache;
1036 unsigned long flags;
1037 int i;
1038
1039 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
1040 rcache = &iovad->rcaches[i];
1041 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
1042 spin_lock_irqsave(&cpu_rcache->lock, flags);
1043 iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
1044 iova_magazine_free_pfns(cpu_rcache->prev, iovad);
1045 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
1046 }
1047}
1048
1049MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
1050MODULE_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");