1 /*
2  * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
3  * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <linux/errno.h>
35 #include <linux/slab.h>
36 #include <linux/mm.h>
37 #include <linux/export.h>
38 #include <linux/bitmap.h>
39 #include <linux/dma-mapping.h>
40 #include <linux/vmalloc.h>
41 
42 #include "mlx4.h"
43 
44 u32 mlx4_bitmap_alloc(struct mlx4_bitmap *bitmap)
45 {
46 	u32 obj;
47 
48 	spin_lock(&bitmap->lock);
49 
50 	obj = find_next_zero_bit(bitmap->table, bitmap->max, bitmap->last);
51 	if (obj >= bitmap->max) {
52 		bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
53 				& bitmap->mask;
54 		obj = find_first_zero_bit(bitmap->table, bitmap->max);
55 	}
56 
57 	if (obj < bitmap->max) {
58 		set_bit(obj, bitmap->table);
59 		bitmap->last = (obj + 1);
60 		if (bitmap->last == bitmap->max)
61 			bitmap->last = 0;
62 		obj |= bitmap->top;
63 	} else
64 		obj = -1;
65 
66 	if (obj != -1)
67 		--bitmap->avail;
68 
69 	spin_unlock(&bitmap->lock);
70 
71 	return obj;
72 }
73 
74 void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj, int use_rr)
75 {
76 	mlx4_bitmap_free_range(bitmap, obj, 1, use_rr);
77 }
78 
79 static unsigned long find_aligned_range(unsigned long *bitmap,
80 					u32 start, u32 nbits,
81 					int len, int align, u32 skip_mask)
82 {
83 	unsigned long end, i;
84 
85 again:
86 	start = ALIGN(start, align);
87 
88 	while ((start < nbits) && (test_bit(start, bitmap) ||
89 				   (start & skip_mask)))
90 		start += align;
91 
92 	if (start >= nbits)
93 		return -1;
94 
95 	end = start+len;
96 	if (end > nbits)
97 		return -1;
98 
99 	for (i = start + 1; i < end; i++) {
100 		if (test_bit(i, bitmap) || ((u32)i & skip_mask)) {
101 			start = i + 1;
102 			goto again;
103 		}
104 	}
105 
106 	return start;
107 }
108 
109 u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt,
110 			    int align, u32 skip_mask)
111 {
112 	u32 obj;
113 
114 	if (likely(cnt == 1 && align == 1 && !skip_mask))
115 		return mlx4_bitmap_alloc(bitmap);
116 
117 	spin_lock(&bitmap->lock);
118 
119 	obj = find_aligned_range(bitmap->table, bitmap->last,
120 				 bitmap->max, cnt, align, skip_mask);
121 	if (obj >= bitmap->max) {
122 		bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
123 				& bitmap->mask;
124 		obj = find_aligned_range(bitmap->table, 0, bitmap->max,
125 					 cnt, align, skip_mask);
126 	}
127 
128 	if (obj < bitmap->max) {
129 		bitmap_set(bitmap->table, obj, cnt);
130 		if (obj == bitmap->last) {
131 			bitmap->last = (obj + cnt);
132 			if (bitmap->last >= bitmap->max)
133 				bitmap->last = 0;
134 		}
135 		obj |= bitmap->top;
136 	} else
137 		obj = -1;
138 
139 	if (obj != -1)
140 		bitmap->avail -= cnt;
141 
142 	spin_unlock(&bitmap->lock);
143 
144 	return obj;
145 }
146 
147 u32 mlx4_bitmap_avail(struct mlx4_bitmap *bitmap)
148 {
149 	return bitmap->avail;
150 }
151 
152 static u32 mlx4_bitmap_masked_value(struct mlx4_bitmap *bitmap, u32 obj)
153 {
154 	return obj & (bitmap->max + bitmap->reserved_top - 1);
155 }
156 
157 void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt,
158 			    int use_rr)
159 {
160 	obj &= bitmap->max + bitmap->reserved_top - 1;
161 
162 	spin_lock(&bitmap->lock);
163 	if (!use_rr) {
164 		bitmap->last = min(bitmap->last, obj);
165 		bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
166 				& bitmap->mask;
167 	}
168 	bitmap_clear(bitmap->table, obj, cnt);
169 	bitmap->avail += cnt;
170 	spin_unlock(&bitmap->lock);
171 }
172 
173 int mlx4_bitmap_init(struct mlx4_bitmap *bitmap, u32 num, u32 mask,
174 		     u32 reserved_bot, u32 reserved_top)
175 {
176 	/* num must be a power of 2 */
177 	if (num != roundup_pow_of_two(num))
178 		return -EINVAL;
179 
180 	bitmap->last = 0;
181 	bitmap->top  = 0;
182 	bitmap->max  = num - reserved_top;
183 	bitmap->mask = mask;
184 	bitmap->reserved_top = reserved_top;
185 	bitmap->avail = num - reserved_top - reserved_bot;
186 	bitmap->effective_len = bitmap->avail;
187 	spin_lock_init(&bitmap->lock);
188 	bitmap->table = kcalloc(BITS_TO_LONGS(bitmap->max), sizeof(long),
189 				GFP_KERNEL);
190 	if (!bitmap->table)
191 		return -ENOMEM;
192 
193 	bitmap_set(bitmap->table, 0, reserved_bot);
194 
195 	return 0;
196 }
197 
198 void mlx4_bitmap_cleanup(struct mlx4_bitmap *bitmap)
199 {
200 	kfree(bitmap->table);
201 }
202 
203 struct mlx4_zone_allocator {
204 	struct list_head		entries;
205 	struct list_head		prios;
206 	u32				last_uid;
207 	u32				mask;
208 	/* protect the zone_allocator from concurrent accesses */
209 	spinlock_t			lock;
210 	enum mlx4_zone_alloc_flags	flags;
211 };
212 
213 struct mlx4_zone_entry {
214 	struct list_head		list;
215 	struct list_head		prio_list;
216 	u32				uid;
217 	struct mlx4_zone_allocator	*allocator;
218 	struct mlx4_bitmap		*bitmap;
219 	int				use_rr;
220 	int				priority;
221 	int				offset;
222 	enum mlx4_zone_flags		flags;
223 };
224 
225 struct mlx4_zone_allocator *mlx4_zone_allocator_create(enum mlx4_zone_alloc_flags flags)
226 {
227 	struct mlx4_zone_allocator *zones = kmalloc(sizeof(*zones), GFP_KERNEL);
228 
229 	if (NULL == zones)
230 		return NULL;
231 
232 	INIT_LIST_HEAD(&zones->entries);
233 	INIT_LIST_HEAD(&zones->prios);
234 	spin_lock_init(&zones->lock);
235 	zones->last_uid = 0;
236 	zones->mask = 0;
237 	zones->flags = flags;
238 
239 	return zones;
240 }
241 
242 int mlx4_zone_add_one(struct mlx4_zone_allocator *zone_alloc,
243 		      struct mlx4_bitmap *bitmap,
244 		      u32 flags,
245 		      int priority,
246 		      int offset,
247 		      u32 *puid)
248 {
249 	u32 mask = mlx4_bitmap_masked_value(bitmap, (u32)-1);
250 	struct mlx4_zone_entry *it;
251 	struct mlx4_zone_entry *zone = kmalloc(sizeof(*zone), GFP_KERNEL);
252 
253 	if (NULL == zone)
254 		return -ENOMEM;
255 
256 	zone->flags = flags;
257 	zone->bitmap = bitmap;
258 	zone->use_rr = (flags & MLX4_ZONE_USE_RR) ? MLX4_USE_RR : 0;
259 	zone->priority = priority;
260 	zone->offset = offset;
261 
262 	spin_lock(&zone_alloc->lock);
263 
264 	zone->uid = zone_alloc->last_uid++;
265 	zone->allocator = zone_alloc;
266 
267 	if (zone_alloc->mask < mask)
268 		zone_alloc->mask = mask;
269 
270 	list_for_each_entry(it, &zone_alloc->prios, prio_list)
271 		if (it->priority >= priority)
272 			break;
273 
274 	if (&it->prio_list == &zone_alloc->prios || it->priority > priority)
275 		list_add_tail(&zone->prio_list, &it->prio_list);
276 	list_add_tail(&zone->list, &it->list);
277 
278 	spin_unlock(&zone_alloc->lock);
279 
280 	*puid = zone->uid;
281 
282 	return 0;
283 }
284 
285 /* Should be called under a lock */
286 static void __mlx4_zone_remove_one_entry(struct mlx4_zone_entry *entry)
287 {
288 	struct mlx4_zone_allocator *zone_alloc = entry->allocator;
289 
290 	if (!list_empty(&entry->prio_list)) {
291 		/* Check if we need to add an alternative node to the prio list */
292 		if (!list_is_last(&entry->list, &zone_alloc->entries)) {
293 			struct mlx4_zone_entry *next = list_first_entry(&entry->list,
294 									typeof(*next),
295 									list);
296 
297 			if (next->priority == entry->priority)
298 				list_add_tail(&next->prio_list, &entry->prio_list);
299 		}
300 
301 		list_del(&entry->prio_list);
302 	}
303 
304 	list_del(&entry->list);
305 
306 	if (zone_alloc->flags & MLX4_ZONE_ALLOC_FLAGS_NO_OVERLAP) {
307 		u32 mask = 0;
308 		struct mlx4_zone_entry *it;
309 
310 		list_for_each_entry(it, &zone_alloc->prios, prio_list) {
311 			u32 cur_mask = mlx4_bitmap_masked_value(it->bitmap, (u32)-1);
312 
313 			if (mask < cur_mask)
314 				mask = cur_mask;
315 		}
316 		zone_alloc->mask = mask;
317 	}
318 }
319 
320 void mlx4_zone_allocator_destroy(struct mlx4_zone_allocator *zone_alloc)
321 {
322 	struct mlx4_zone_entry *zone, *tmp;
323 
324 	spin_lock(&zone_alloc->lock);
325 
326 	list_for_each_entry_safe(zone, tmp, &zone_alloc->entries, list) {
327 		list_del(&zone->list);
328 		list_del(&zone->prio_list);
329 		kfree(zone);
330 	}
331 
332 	spin_unlock(&zone_alloc->lock);
333 	kfree(zone_alloc);
334 }
335 
336 /* Should be called under a lock */
337 static u32 __mlx4_alloc_from_zone(struct mlx4_zone_entry *zone, int count,
338 				  int align, u32 skip_mask, u32 *puid)
339 {
340 	u32 uid = 0;
341 	u32 res;
342 	struct mlx4_zone_allocator *zone_alloc = zone->allocator;
343 	struct mlx4_zone_entry *curr_node;
344 
345 	res = mlx4_bitmap_alloc_range(zone->bitmap, count,
346 				      align, skip_mask);
347 
348 	if (res != (u32)-1) {
349 		res += zone->offset;
350 		uid = zone->uid;
351 		goto out;
352 	}
353 
354 	list_for_each_entry(curr_node, &zone_alloc->prios, prio_list) {
355 		if (unlikely(curr_node->priority == zone->priority))
356 			break;
357 	}
358 
359 	if (zone->flags & MLX4_ZONE_ALLOW_ALLOC_FROM_LOWER_PRIO) {
360 		struct mlx4_zone_entry *it = curr_node;
361 
362 		list_for_each_entry_continue_reverse(it, &zone_alloc->entries, list) {
363 			res = mlx4_bitmap_alloc_range(it->bitmap, count,
364 						      align, skip_mask);
365 			if (res != (u32)-1) {
366 				res += it->offset;
367 				uid = it->uid;
368 				goto out;
369 			}
370 		}
371 	}
372 
373 	if (zone->flags & MLX4_ZONE_ALLOW_ALLOC_FROM_EQ_PRIO) {
374 		struct mlx4_zone_entry *it = curr_node;
375 
376 		list_for_each_entry_from(it, &zone_alloc->entries, list) {
377 			if (unlikely(it == zone))
378 				continue;
379 
380 			if (unlikely(it->priority != curr_node->priority))
381 				break;
382 
383 			res = mlx4_bitmap_alloc_range(it->bitmap, count,
384 						      align, skip_mask);
385 			if (res != (u32)-1) {
386 				res += it->offset;
387 				uid = it->uid;
388 				goto out;
389 			}
390 		}
391 	}
392 
393 	if (zone->flags & MLX4_ZONE_FALLBACK_TO_HIGHER_PRIO) {
394 		if (list_is_last(&curr_node->prio_list, &zone_alloc->prios))
395 			goto out;
396 
397 		curr_node = list_first_entry(&curr_node->prio_list,
398 					     typeof(*curr_node),
399 					     prio_list);
400 
401 		list_for_each_entry_from(curr_node, &zone_alloc->entries, list) {
402 			res = mlx4_bitmap_alloc_range(curr_node->bitmap, count,
403 						      align, skip_mask);
404 			if (res != (u32)-1) {
405 				res += curr_node->offset;
406 				uid = curr_node->uid;
407 				goto out;
408 			}
409 		}
410 	}
411 
412 out:
413 	if (NULL != puid && res != (u32)-1)
414 		*puid = uid;
415 	return res;
416 }
417 
418 /* Should be called under a lock */
419 static void __mlx4_free_from_zone(struct mlx4_zone_entry *zone, u32 obj,
420 				  u32 count)
421 {
422 	mlx4_bitmap_free_range(zone->bitmap, obj - zone->offset, count, zone->use_rr);
423 }
424 
425 /* Should be called under a lock */
426 static struct mlx4_zone_entry *__mlx4_find_zone_by_uid(
427 		struct mlx4_zone_allocator *zones, u32 uid)
428 {
429 	struct mlx4_zone_entry *zone;
430 
431 	list_for_each_entry(zone, &zones->entries, list) {
432 		if (zone->uid == uid)
433 			return zone;
434 	}
435 
436 	return NULL;
437 }
438 
439 struct mlx4_bitmap *mlx4_zone_get_bitmap(struct mlx4_zone_allocator *zones, u32 uid)
440 {
441 	struct mlx4_zone_entry *zone;
442 	struct mlx4_bitmap *bitmap;
443 
444 	spin_lock(&zones->lock);
445 
446 	zone = __mlx4_find_zone_by_uid(zones, uid);
447 
448 	bitmap = zone == NULL ? NULL : zone->bitmap;
449 
450 	spin_unlock(&zones->lock);
451 
452 	return bitmap;
453 }
454 
455 int mlx4_zone_remove_one(struct mlx4_zone_allocator *zones, u32 uid)
456 {
457 	struct mlx4_zone_entry *zone;
458 	int res = 0;
459 
460 	spin_lock(&zones->lock);
461 
462 	zone = __mlx4_find_zone_by_uid(zones, uid);
463 
464 	if (NULL == zone) {
465 		res = -1;
466 		goto out;
467 	}
468 
469 	__mlx4_zone_remove_one_entry(zone);
470 
471 out:
472 	spin_unlock(&zones->lock);
473 	kfree(zone);
474 
475 	return res;
476 }
477 
478 /* Should be called under a lock */
479 static struct mlx4_zone_entry *__mlx4_find_zone_by_uid_unique(
480 		struct mlx4_zone_allocator *zones, u32 obj)
481 {
482 	struct mlx4_zone_entry *zone, *zone_candidate = NULL;
483 	u32 dist = (u32)-1;
484 
485 	/* Search for the smallest zone that this obj could be
486 	 * allocated from. This is done in order to handle
487 	 * situations when small bitmaps are allocated from bigger
488 	 * bitmaps (and the allocated space is marked as reserved in
489 	 * the bigger bitmap.
490 	 */
491 	list_for_each_entry(zone, &zones->entries, list) {
492 		if (obj >= zone->offset) {
493 			u32 mobj = (obj - zone->offset) & zones->mask;
494 
495 			if (mobj < zone->bitmap->max) {
496 				u32 curr_dist = zone->bitmap->effective_len;
497 
498 				if (curr_dist < dist) {
499 					dist = curr_dist;
500 					zone_candidate = zone;
501 				}
502 			}
503 		}
504 	}
505 
506 	return zone_candidate;
507 }
508 
509 u32 mlx4_zone_alloc_entries(struct mlx4_zone_allocator *zones, u32 uid, int count,
510 			    int align, u32 skip_mask, u32 *puid)
511 {
512 	struct mlx4_zone_entry *zone;
513 	int res = -1;
514 
515 	spin_lock(&zones->lock);
516 
517 	zone = __mlx4_find_zone_by_uid(zones, uid);
518 
519 	if (NULL == zone)
520 		goto out;
521 
522 	res = __mlx4_alloc_from_zone(zone, count, align, skip_mask, puid);
523 
524 out:
525 	spin_unlock(&zones->lock);
526 
527 	return res;
528 }
529 
530 u32 mlx4_zone_free_entries(struct mlx4_zone_allocator *zones, u32 uid, u32 obj, u32 count)
531 {
532 	struct mlx4_zone_entry *zone;
533 	int res = 0;
534 
535 	spin_lock(&zones->lock);
536 
537 	zone = __mlx4_find_zone_by_uid(zones, uid);
538 
539 	if (NULL == zone) {
540 		res = -1;
541 		goto out;
542 	}
543 
544 	__mlx4_free_from_zone(zone, obj, count);
545 
546 out:
547 	spin_unlock(&zones->lock);
548 
549 	return res;
550 }
551 
552 u32 mlx4_zone_free_entries_unique(struct mlx4_zone_allocator *zones, u32 obj, u32 count)
553 {
554 	struct mlx4_zone_entry *zone;
555 	int res;
556 
557 	if (!(zones->flags & MLX4_ZONE_ALLOC_FLAGS_NO_OVERLAP))
558 		return -EFAULT;
559 
560 	spin_lock(&zones->lock);
561 
562 	zone = __mlx4_find_zone_by_uid_unique(zones, obj);
563 
564 	if (NULL == zone) {
565 		res = -1;
566 		goto out;
567 	}
568 
569 	__mlx4_free_from_zone(zone, obj, count);
570 	res = 0;
571 
572 out:
573 	spin_unlock(&zones->lock);
574 
575 	return res;
576 }
577 
578 static int mlx4_buf_direct_alloc(struct mlx4_dev *dev, int size,
579 				 struct mlx4_buf *buf)
580 {
581 	dma_addr_t t;
582 
583 	buf->nbufs        = 1;
584 	buf->npages       = 1;
585 	buf->page_shift   = get_order(size) + PAGE_SHIFT;
586 	buf->direct.buf   =
587 		dma_alloc_coherent(&dev->persist->pdev->dev, size, &t,
588 				   GFP_KERNEL);
589 	if (!buf->direct.buf)
590 		return -ENOMEM;
591 
592 	buf->direct.map = t;
593 
594 	while (t & ((1 << buf->page_shift) - 1)) {
595 		--buf->page_shift;
596 		buf->npages *= 2;
597 	}
598 
599 	return 0;
600 }
601 
602 /* Handling for queue buffers -- we allocate a bunch of memory and
603  * register it in a memory region at HCA virtual address 0. If the
604  *  requested size is > max_direct, we split the allocation into
605  *  multiple pages, so we don't require too much contiguous memory.
606  */
607 int mlx4_buf_alloc(struct mlx4_dev *dev, int size, int max_direct,
608 		   struct mlx4_buf *buf)
609 {
610 	if (size <= max_direct) {
611 		return mlx4_buf_direct_alloc(dev, size, buf);
612 	} else {
613 		dma_addr_t t;
614 		int i;
615 
616 		buf->direct.buf = NULL;
617 		buf->nbufs      = DIV_ROUND_UP(size, PAGE_SIZE);
618 		buf->npages	= buf->nbufs;
619 		buf->page_shift  = PAGE_SHIFT;
620 		buf->page_list   = kcalloc(buf->nbufs, sizeof(*buf->page_list),
621 					   GFP_KERNEL);
622 		if (!buf->page_list)
623 			return -ENOMEM;
624 
625 		for (i = 0; i < buf->nbufs; ++i) {
626 			buf->page_list[i].buf =
627 				dma_alloc_coherent(&dev->persist->pdev->dev,
628 						   PAGE_SIZE, &t, GFP_KERNEL);
629 			if (!buf->page_list[i].buf)
630 				goto err_free;
631 
632 			buf->page_list[i].map = t;
633 		}
634 	}
635 
636 	return 0;
637 
638 err_free:
639 	mlx4_buf_free(dev, size, buf);
640 
641 	return -ENOMEM;
642 }
643 EXPORT_SYMBOL_GPL(mlx4_buf_alloc);
644 
645 void mlx4_buf_free(struct mlx4_dev *dev, int size, struct mlx4_buf *buf)
646 {
647 	if (buf->nbufs == 1) {
648 		dma_free_coherent(&dev->persist->pdev->dev, size,
649 				  buf->direct.buf, buf->direct.map);
650 	} else {
651 		int i;
652 
653 		for (i = 0; i < buf->nbufs; ++i)
654 			if (buf->page_list[i].buf)
655 				dma_free_coherent(&dev->persist->pdev->dev,
656 						  PAGE_SIZE,
657 						  buf->page_list[i].buf,
658 						  buf->page_list[i].map);
659 		kfree(buf->page_list);
660 	}
661 }
662 EXPORT_SYMBOL_GPL(mlx4_buf_free);
663 
664 static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device)
665 {
666 	struct mlx4_db_pgdir *pgdir;
667 
668 	pgdir = kzalloc(sizeof(*pgdir), GFP_KERNEL);
669 	if (!pgdir)
670 		return NULL;
671 
672 	bitmap_fill(pgdir->order1, MLX4_DB_PER_PAGE / 2);
673 	pgdir->bits[0] = pgdir->order0;
674 	pgdir->bits[1] = pgdir->order1;
675 	pgdir->db_page = dma_alloc_coherent(dma_device, PAGE_SIZE,
676 					    &pgdir->db_dma, GFP_KERNEL);
677 	if (!pgdir->db_page) {
678 		kfree(pgdir);
679 		return NULL;
680 	}
681 
682 	return pgdir;
683 }
684 
685 static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir,
686 				    struct mlx4_db *db, int order)
687 {
688 	int o;
689 	int i;
690 
691 	for (o = order; o <= 1; ++o) {
692 		i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o);
693 		if (i < MLX4_DB_PER_PAGE >> o)
694 			goto found;
695 	}
696 
697 	return -ENOMEM;
698 
699 found:
700 	clear_bit(i, pgdir->bits[o]);
701 
702 	i <<= o;
703 
704 	if (o > order)
705 		set_bit(i ^ 1, pgdir->bits[order]);
706 
707 	db->u.pgdir = pgdir;
708 	db->index   = i;
709 	db->db      = pgdir->db_page + db->index;
710 	db->dma     = pgdir->db_dma  + db->index * 4;
711 	db->order   = order;
712 
713 	return 0;
714 }
715 
716 int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order)
717 {
718 	struct mlx4_priv *priv = mlx4_priv(dev);
719 	struct mlx4_db_pgdir *pgdir;
720 	int ret = 0;
721 
722 	mutex_lock(&priv->pgdir_mutex);
723 
724 	list_for_each_entry(pgdir, &priv->pgdir_list, list)
725 		if (!mlx4_alloc_db_from_pgdir(pgdir, db, order))
726 			goto out;
727 
728 	pgdir = mlx4_alloc_db_pgdir(&dev->persist->pdev->dev);
729 	if (!pgdir) {
730 		ret = -ENOMEM;
731 		goto out;
732 	}
733 
734 	list_add(&pgdir->list, &priv->pgdir_list);
735 
736 	/* This should never fail -- we just allocated an empty page: */
737 	WARN_ON(mlx4_alloc_db_from_pgdir(pgdir, db, order));
738 
739 out:
740 	mutex_unlock(&priv->pgdir_mutex);
741 
742 	return ret;
743 }
744 EXPORT_SYMBOL_GPL(mlx4_db_alloc);
745 
746 void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db)
747 {
748 	struct mlx4_priv *priv = mlx4_priv(dev);
749 	int o;
750 	int i;
751 
752 	mutex_lock(&priv->pgdir_mutex);
753 
754 	o = db->order;
755 	i = db->index;
756 
757 	if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
758 		clear_bit(i ^ 1, db->u.pgdir->order0);
759 		++o;
760 	}
761 	i >>= o;
762 	set_bit(i, db->u.pgdir->bits[o]);
763 
764 	if (bitmap_full(db->u.pgdir->order1, MLX4_DB_PER_PAGE / 2)) {
765 		dma_free_coherent(&dev->persist->pdev->dev, PAGE_SIZE,
766 				  db->u.pgdir->db_page, db->u.pgdir->db_dma);
767 		list_del(&db->u.pgdir->list);
768 		kfree(db->u.pgdir);
769 	}
770 
771 	mutex_unlock(&priv->pgdir_mutex);
772 }
773 EXPORT_SYMBOL_GPL(mlx4_db_free);
774 
775 int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
776 		       int size)
777 {
778 	int err;
779 
780 	err = mlx4_db_alloc(dev, &wqres->db, 1);
781 	if (err)
782 		return err;
783 
784 	*wqres->db.db = 0;
785 
786 	err = mlx4_buf_direct_alloc(dev, size, &wqres->buf);
787 	if (err)
788 		goto err_db;
789 
790 	err = mlx4_mtt_init(dev, wqres->buf.npages, wqres->buf.page_shift,
791 			    &wqres->mtt);
792 	if (err)
793 		goto err_buf;
794 
795 	err = mlx4_buf_write_mtt(dev, &wqres->mtt, &wqres->buf);
796 	if (err)
797 		goto err_mtt;
798 
799 	return 0;
800 
801 err_mtt:
802 	mlx4_mtt_cleanup(dev, &wqres->mtt);
803 err_buf:
804 	mlx4_buf_free(dev, size, &wqres->buf);
805 err_db:
806 	mlx4_db_free(dev, &wqres->db);
807 
808 	return err;
809 }
810 EXPORT_SYMBOL_GPL(mlx4_alloc_hwq_res);
811 
812 void mlx4_free_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
813 		       int size)
814 {
815 	mlx4_mtt_cleanup(dev, &wqres->mtt);
816 	mlx4_buf_free(dev, size, &wqres->buf);
817 	mlx4_db_free(dev, &wqres->db);
818 }
819 EXPORT_SYMBOL_GPL(mlx4_free_hwq_res);
820