1 /*
2  * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  *
34  * $Id$
35  */
36 
37 #include <linux/mm.h>
38 
39 #include "mthca_memfree.h"
40 #include "mthca_dev.h"
41 #include "mthca_cmd.h"
42 
43 /*
44  * We allocate in as big chunks as we can, up to a maximum of 256 KB
45  * per chunk.
46  */
47 enum {
48 	MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
49 	MTHCA_TABLE_CHUNK_SIZE = 1 << 18
50 };
51 
52 struct mthca_user_db_table {
53 	struct semaphore mutex;
54 	struct {
55 		u64                uvirt;
56 		struct scatterlist mem;
57 		int                refcount;
58 	}                page[0];
59 };
60 
61 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm)
62 {
63 	struct mthca_icm_chunk *chunk, *tmp;
64 	int i;
65 
66 	if (!icm)
67 		return;
68 
69 	list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
70 		if (chunk->nsg > 0)
71 			pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
72 				     PCI_DMA_BIDIRECTIONAL);
73 
74 		for (i = 0; i < chunk->npages; ++i)
75 			__free_pages(chunk->mem[i].page,
76 				     get_order(chunk->mem[i].length));
77 
78 		kfree(chunk);
79 	}
80 
81 	kfree(icm);
82 }
83 
84 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
85 				  gfp_t gfp_mask)
86 {
87 	struct mthca_icm *icm;
88 	struct mthca_icm_chunk *chunk = NULL;
89 	int cur_order;
90 
91 	icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
92 	if (!icm)
93 		return icm;
94 
95 	icm->refcount = 0;
96 	INIT_LIST_HEAD(&icm->chunk_list);
97 
98 	cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
99 
100 	while (npages > 0) {
101 		if (!chunk) {
102 			chunk = kmalloc(sizeof *chunk,
103 					gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
104 			if (!chunk)
105 				goto fail;
106 
107 			chunk->npages = 0;
108 			chunk->nsg    = 0;
109 			list_add_tail(&chunk->list, &icm->chunk_list);
110 		}
111 
112 		while (1 << cur_order > npages)
113 			--cur_order;
114 
115 		chunk->mem[chunk->npages].page = alloc_pages(gfp_mask, cur_order);
116 		if (chunk->mem[chunk->npages].page) {
117 			chunk->mem[chunk->npages].length = PAGE_SIZE << cur_order;
118 			chunk->mem[chunk->npages].offset = 0;
119 
120 			if (++chunk->npages == MTHCA_ICM_CHUNK_LEN) {
121 				chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
122 							chunk->npages,
123 							PCI_DMA_BIDIRECTIONAL);
124 
125 				if (chunk->nsg <= 0)
126 					goto fail;
127 
128 				chunk = NULL;
129 			}
130 
131 			npages -= 1 << cur_order;
132 		} else {
133 			--cur_order;
134 			if (cur_order < 0)
135 				goto fail;
136 		}
137 	}
138 
139 	if (chunk) {
140 		chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
141 					chunk->npages,
142 					PCI_DMA_BIDIRECTIONAL);
143 
144 		if (chunk->nsg <= 0)
145 			goto fail;
146 	}
147 
148 	return icm;
149 
150 fail:
151 	mthca_free_icm(dev, icm);
152 	return NULL;
153 }
154 
155 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
156 {
157 	int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
158 	int ret = 0;
159 	u8 status;
160 
161 	down(&table->mutex);
162 
163 	if (table->icm[i]) {
164 		++table->icm[i]->refcount;
165 		goto out;
166 	}
167 
168 	table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
169 					(table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
170 					__GFP_NOWARN);
171 	if (!table->icm[i]) {
172 		ret = -ENOMEM;
173 		goto out;
174 	}
175 
176 	if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
177 			  &status) || status) {
178 		mthca_free_icm(dev, table->icm[i]);
179 		table->icm[i] = NULL;
180 		ret = -ENOMEM;
181 		goto out;
182 	}
183 
184 	++table->icm[i]->refcount;
185 
186 out:
187 	up(&table->mutex);
188 	return ret;
189 }
190 
191 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
192 {
193 	int i;
194 	u8 status;
195 
196 	if (!mthca_is_memfree(dev))
197 		return;
198 
199 	i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
200 
201 	down(&table->mutex);
202 
203 	if (--table->icm[i]->refcount == 0) {
204 		mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
205 				MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
206 		mthca_free_icm(dev, table->icm[i]);
207 		table->icm[i] = NULL;
208 	}
209 
210 	up(&table->mutex);
211 }
212 
213 void *mthca_table_find(struct mthca_icm_table *table, int obj)
214 {
215 	int idx, offset, i;
216 	struct mthca_icm_chunk *chunk;
217 	struct mthca_icm *icm;
218 	struct page *page = NULL;
219 
220 	if (!table->lowmem)
221 		return NULL;
222 
223 	down(&table->mutex);
224 
225 	idx = (obj & (table->num_obj - 1)) * table->obj_size;
226 	icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
227 	offset = idx % MTHCA_TABLE_CHUNK_SIZE;
228 
229 	if (!icm)
230 		goto out;
231 
232 	list_for_each_entry(chunk, &icm->chunk_list, list) {
233 		for (i = 0; i < chunk->npages; ++i) {
234 			if (chunk->mem[i].length >= offset) {
235 				page = chunk->mem[i].page;
236 				goto out;
237 			}
238 			offset -= chunk->mem[i].length;
239 		}
240 	}
241 
242 out:
243 	up(&table->mutex);
244 	return page ? lowmem_page_address(page) + offset : NULL;
245 }
246 
247 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
248 			  int start, int end)
249 {
250 	int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
251 	int i, err;
252 
253 	for (i = start; i <= end; i += inc) {
254 		err = mthca_table_get(dev, table, i);
255 		if (err)
256 			goto fail;
257 	}
258 
259 	return 0;
260 
261 fail:
262 	while (i > start) {
263 		i -= inc;
264 		mthca_table_put(dev, table, i);
265 	}
266 
267 	return err;
268 }
269 
270 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
271 			   int start, int end)
272 {
273 	int i;
274 
275 	if (!mthca_is_memfree(dev))
276 		return;
277 
278 	for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
279 		mthca_table_put(dev, table, i);
280 }
281 
282 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
283 					      u64 virt, int obj_size,
284 					      int nobj, int reserved,
285 					      int use_lowmem)
286 {
287 	struct mthca_icm_table *table;
288 	int num_icm;
289 	unsigned chunk_size;
290 	int i;
291 	u8 status;
292 
293 	num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
294 
295 	table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
296 	if (!table)
297 		return NULL;
298 
299 	table->virt     = virt;
300 	table->num_icm  = num_icm;
301 	table->num_obj  = nobj;
302 	table->obj_size = obj_size;
303 	table->lowmem   = use_lowmem;
304 	init_MUTEX(&table->mutex);
305 
306 	for (i = 0; i < num_icm; ++i)
307 		table->icm[i] = NULL;
308 
309 	for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
310 		chunk_size = MTHCA_TABLE_CHUNK_SIZE;
311 		if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
312 			chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
313 
314 		table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
315 						(use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
316 						__GFP_NOWARN);
317 		if (!table->icm[i])
318 			goto err;
319 		if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
320 				  &status) || status) {
321 			mthca_free_icm(dev, table->icm[i]);
322 			table->icm[i] = NULL;
323 			goto err;
324 		}
325 
326 		/*
327 		 * Add a reference to this ICM chunk so that it never
328 		 * gets freed (since it contains reserved firmware objects).
329 		 */
330 		++table->icm[i]->refcount;
331 	}
332 
333 	return table;
334 
335 err:
336 	for (i = 0; i < num_icm; ++i)
337 		if (table->icm[i]) {
338 			mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
339 					MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
340 			mthca_free_icm(dev, table->icm[i]);
341 		}
342 
343 	kfree(table);
344 
345 	return NULL;
346 }
347 
348 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
349 {
350 	int i;
351 	u8 status;
352 
353 	for (i = 0; i < table->num_icm; ++i)
354 		if (table->icm[i]) {
355 			mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
356 					MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
357 			mthca_free_icm(dev, table->icm[i]);
358 		}
359 
360 	kfree(table);
361 }
362 
363 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
364 {
365 	return dev->uar_table.uarc_base +
366 		uar->index * dev->uar_table.uarc_size +
367 		page * 4096;
368 }
369 
370 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
371 		      struct mthca_user_db_table *db_tab, int index, u64 uaddr)
372 {
373 	int ret = 0;
374 	u8 status;
375 	int i;
376 
377 	if (!mthca_is_memfree(dev))
378 		return 0;
379 
380 	if (index < 0 || index > dev->uar_table.uarc_size / 8)
381 		return -EINVAL;
382 
383 	down(&db_tab->mutex);
384 
385 	i = index / MTHCA_DB_REC_PER_PAGE;
386 
387 	if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
388 	    (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
389 	    (uaddr & 4095)) {
390 		ret = -EINVAL;
391 		goto out;
392 	}
393 
394 	if (db_tab->page[i].refcount) {
395 		++db_tab->page[i].refcount;
396 		goto out;
397 	}
398 
399 	ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
400 			     &db_tab->page[i].mem.page, NULL);
401 	if (ret < 0)
402 		goto out;
403 
404 	db_tab->page[i].mem.length = 4096;
405 	db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
406 
407 	ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
408 	if (ret < 0) {
409 		put_page(db_tab->page[i].mem.page);
410 		goto out;
411 	}
412 
413 	ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
414 				 mthca_uarc_virt(dev, uar, i), &status);
415 	if (!ret && status)
416 		ret = -EINVAL;
417 	if (ret) {
418 		pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
419 		put_page(db_tab->page[i].mem.page);
420 		goto out;
421 	}
422 
423 	db_tab->page[i].uvirt    = uaddr;
424 	db_tab->page[i].refcount = 1;
425 
426 out:
427 	up(&db_tab->mutex);
428 	return ret;
429 }
430 
431 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
432 			 struct mthca_user_db_table *db_tab, int index)
433 {
434 	if (!mthca_is_memfree(dev))
435 		return;
436 
437 	/*
438 	 * To make our bookkeeping simpler, we don't unmap DB
439 	 * pages until we clean up the whole db table.
440 	 */
441 
442 	down(&db_tab->mutex);
443 
444 	--db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
445 
446 	up(&db_tab->mutex);
447 }
448 
449 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
450 {
451 	struct mthca_user_db_table *db_tab;
452 	int npages;
453 	int i;
454 
455 	if (!mthca_is_memfree(dev))
456 		return NULL;
457 
458 	npages = dev->uar_table.uarc_size / 4096;
459 	db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
460 	if (!db_tab)
461 		return ERR_PTR(-ENOMEM);
462 
463 	init_MUTEX(&db_tab->mutex);
464 	for (i = 0; i < npages; ++i) {
465 		db_tab->page[i].refcount = 0;
466 		db_tab->page[i].uvirt    = 0;
467 	}
468 
469 	return db_tab;
470 }
471 
472 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
473 			       struct mthca_user_db_table *db_tab)
474 {
475 	int i;
476 	u8 status;
477 
478 	if (!mthca_is_memfree(dev))
479 		return;
480 
481 	for (i = 0; i < dev->uar_table.uarc_size / 4096; ++i) {
482 		if (db_tab->page[i].uvirt) {
483 			mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
484 			pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
485 			put_page(db_tab->page[i].mem.page);
486 		}
487 	}
488 
489 	kfree(db_tab);
490 }
491 
492 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
493 		   u32 qn, __be32 **db)
494 {
495 	int group;
496 	int start, end, dir;
497 	int i, j;
498 	struct mthca_db_page *page;
499 	int ret = 0;
500 	u8 status;
501 
502 	down(&dev->db_tab->mutex);
503 
504 	switch (type) {
505 	case MTHCA_DB_TYPE_CQ_ARM:
506 	case MTHCA_DB_TYPE_SQ:
507 		group = 0;
508 		start = 0;
509 		end   = dev->db_tab->max_group1;
510 		dir   = 1;
511 		break;
512 
513 	case MTHCA_DB_TYPE_CQ_SET_CI:
514 	case MTHCA_DB_TYPE_RQ:
515 	case MTHCA_DB_TYPE_SRQ:
516 		group = 1;
517 		start = dev->db_tab->npages - 1;
518 		end   = dev->db_tab->min_group2;
519 		dir   = -1;
520 		break;
521 
522 	default:
523 		ret = -EINVAL;
524 		goto out;
525 	}
526 
527 	for (i = start; i != end; i += dir)
528 		if (dev->db_tab->page[i].db_rec &&
529 		    !bitmap_full(dev->db_tab->page[i].used,
530 				 MTHCA_DB_REC_PER_PAGE)) {
531 			page = dev->db_tab->page + i;
532 			goto found;
533 		}
534 
535 	for (i = start; i != end; i += dir)
536 		if (!dev->db_tab->page[i].db_rec) {
537 			page = dev->db_tab->page + i;
538 			goto alloc;
539 		}
540 
541 	if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
542 		ret = -ENOMEM;
543 		goto out;
544 	}
545 
546 	if (group == 0)
547 		++dev->db_tab->max_group1;
548 	else
549 		--dev->db_tab->min_group2;
550 
551 	page = dev->db_tab->page + end;
552 
553 alloc:
554 	page->db_rec = dma_alloc_coherent(&dev->pdev->dev, 4096,
555 					  &page->mapping, GFP_KERNEL);
556 	if (!page->db_rec) {
557 		ret = -ENOMEM;
558 		goto out;
559 	}
560 	memset(page->db_rec, 0, 4096);
561 
562 	ret = mthca_MAP_ICM_page(dev, page->mapping,
563 				 mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
564 	if (!ret && status)
565 		ret = -EINVAL;
566 	if (ret) {
567 		dma_free_coherent(&dev->pdev->dev, 4096,
568 				  page->db_rec, page->mapping);
569 		goto out;
570 	}
571 
572 	bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
573 
574 found:
575 	j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
576 	set_bit(j, page->used);
577 
578 	if (group == 1)
579 		j = MTHCA_DB_REC_PER_PAGE - 1 - j;
580 
581 	ret = i * MTHCA_DB_REC_PER_PAGE + j;
582 
583 	page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
584 
585 	*db = (__be32 *) &page->db_rec[j];
586 
587 out:
588 	up(&dev->db_tab->mutex);
589 
590 	return ret;
591 }
592 
593 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
594 {
595 	int i, j;
596 	struct mthca_db_page *page;
597 	u8 status;
598 
599 	i = db_index / MTHCA_DB_REC_PER_PAGE;
600 	j = db_index % MTHCA_DB_REC_PER_PAGE;
601 
602 	page = dev->db_tab->page + i;
603 
604 	down(&dev->db_tab->mutex);
605 
606 	page->db_rec[j] = 0;
607 	if (i >= dev->db_tab->min_group2)
608 		j = MTHCA_DB_REC_PER_PAGE - 1 - j;
609 	clear_bit(j, page->used);
610 
611 	if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
612 	    i >= dev->db_tab->max_group1 - 1) {
613 		mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
614 
615 		dma_free_coherent(&dev->pdev->dev, 4096,
616 				  page->db_rec, page->mapping);
617 		page->db_rec = NULL;
618 
619 		if (i == dev->db_tab->max_group1) {
620 			--dev->db_tab->max_group1;
621 			/* XXX may be able to unmap more pages now */
622 		}
623 		if (i == dev->db_tab->min_group2)
624 			++dev->db_tab->min_group2;
625 	}
626 
627 	up(&dev->db_tab->mutex);
628 }
629 
630 int mthca_init_db_tab(struct mthca_dev *dev)
631 {
632 	int i;
633 
634 	if (!mthca_is_memfree(dev))
635 		return 0;
636 
637 	dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
638 	if (!dev->db_tab)
639 		return -ENOMEM;
640 
641 	init_MUTEX(&dev->db_tab->mutex);
642 
643 	dev->db_tab->npages     = dev->uar_table.uarc_size / 4096;
644 	dev->db_tab->max_group1 = 0;
645 	dev->db_tab->min_group2 = dev->db_tab->npages - 1;
646 
647 	dev->db_tab->page = kmalloc(dev->db_tab->npages *
648 				    sizeof *dev->db_tab->page,
649 				    GFP_KERNEL);
650 	if (!dev->db_tab->page) {
651 		kfree(dev->db_tab);
652 		return -ENOMEM;
653 	}
654 
655 	for (i = 0; i < dev->db_tab->npages; ++i)
656 		dev->db_tab->page[i].db_rec = NULL;
657 
658 	return 0;
659 }
660 
661 void mthca_cleanup_db_tab(struct mthca_dev *dev)
662 {
663 	int i;
664 	u8 status;
665 
666 	if (!mthca_is_memfree(dev))
667 		return;
668 
669 	/*
670 	 * Because we don't always free our UARC pages when they
671 	 * become empty to make mthca_free_db() simpler we need to
672 	 * make a sweep through the doorbell pages and free any
673 	 * leftover pages now.
674 	 */
675 	for (i = 0; i < dev->db_tab->npages; ++i) {
676 		if (!dev->db_tab->page[i].db_rec)
677 			continue;
678 
679 		if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
680 			mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
681 
682 		mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
683 
684 		dma_free_coherent(&dev->pdev->dev, 4096,
685 				  dev->db_tab->page[i].db_rec,
686 				  dev->db_tab->page[i].mapping);
687 	}
688 
689 	kfree(dev->db_tab->page);
690 	kfree(dev->db_tab);
691 }
692