Pull dock-bay into release branch
[linux-2.6] / drivers / infiniband / hw / mthca / mthca_memfree.c
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 #include <linux/scatterlist.h>
39 #include <linux/sched.h>
40
41 #include <asm/page.h>
42
43 #include "mthca_memfree.h"
44 #include "mthca_dev.h"
45 #include "mthca_cmd.h"
46
47 /*
48  * We allocate in as big chunks as we can, up to a maximum of 256 KB
49  * per chunk.
50  */
51 enum {
52         MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
53         MTHCA_TABLE_CHUNK_SIZE = 1 << 18
54 };
55
56 struct mthca_user_db_table {
57         struct mutex mutex;
58         struct {
59                 u64                uvirt;
60                 struct scatterlist mem;
61                 int                refcount;
62         }                page[0];
63 };
64
65 static void mthca_free_icm_pages(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
66 {
67         int i;
68
69         if (chunk->nsg > 0)
70                 pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
71                              PCI_DMA_BIDIRECTIONAL);
72
73         for (i = 0; i < chunk->npages; ++i)
74                 __free_pages(chunk->mem[i].page,
75                              get_order(chunk->mem[i].length));
76 }
77
78 static void mthca_free_icm_coherent(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
79 {
80         int i;
81
82         for (i = 0; i < chunk->npages; ++i) {
83                 dma_free_coherent(&dev->pdev->dev, chunk->mem[i].length,
84                                   lowmem_page_address(chunk->mem[i].page),
85                                   sg_dma_address(&chunk->mem[i]));
86         }
87 }
88
89 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent)
90 {
91         struct mthca_icm_chunk *chunk, *tmp;
92
93         if (!icm)
94                 return;
95
96         list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
97                 if (coherent)
98                         mthca_free_icm_coherent(dev, chunk);
99                 else
100                         mthca_free_icm_pages(dev, chunk);
101
102                 kfree(chunk);
103         }
104
105         kfree(icm);
106 }
107
108 static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
109 {
110         mem->page = alloc_pages(gfp_mask, order);
111         if (!mem->page)
112                 return -ENOMEM;
113
114         mem->length = PAGE_SIZE << order;
115         mem->offset = 0;
116         return 0;
117 }
118
119 static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
120                                     int order, gfp_t gfp_mask)
121 {
122         void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
123                                        gfp_mask);
124         if (!buf)
125                 return -ENOMEM;
126
127         sg_set_buf(mem, buf, PAGE_SIZE << order);
128         BUG_ON(mem->offset);
129         sg_dma_len(mem) = PAGE_SIZE << order;
130         return 0;
131 }
132
133 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
134                                   gfp_t gfp_mask, int coherent)
135 {
136         struct mthca_icm *icm;
137         struct mthca_icm_chunk *chunk = NULL;
138         int cur_order;
139         int ret;
140
141         /* We use sg_set_buf for coherent allocs, which assumes low memory */
142         BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));
143
144         icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
145         if (!icm)
146                 return icm;
147
148         icm->refcount = 0;
149         INIT_LIST_HEAD(&icm->chunk_list);
150
151         cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
152
153         while (npages > 0) {
154                 if (!chunk) {
155                         chunk = kmalloc(sizeof *chunk,
156                                         gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
157                         if (!chunk)
158                                 goto fail;
159
160                         chunk->npages = 0;
161                         chunk->nsg    = 0;
162                         list_add_tail(&chunk->list, &icm->chunk_list);
163                 }
164
165                 while (1 << cur_order > npages)
166                         --cur_order;
167
168                 if (coherent)
169                         ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
170                                                        &chunk->mem[chunk->npages],
171                                                        cur_order, gfp_mask);
172                 else
173                         ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
174                                                     cur_order, gfp_mask);
175
176                 if (!ret) {
177                         ++chunk->npages;
178
179                         if (coherent)
180                                 ++chunk->nsg;
181                         else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
182                                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
183                                                         chunk->npages,
184                                                         PCI_DMA_BIDIRECTIONAL);
185
186                                 if (chunk->nsg <= 0)
187                                         goto fail;
188                         }
189
190                         if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
191                                 chunk = NULL;
192
193                         npages -= 1 << cur_order;
194                 } else {
195                         --cur_order;
196                         if (cur_order < 0)
197                                 goto fail;
198                 }
199         }
200
201         if (!coherent && chunk) {
202                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
203                                         chunk->npages,
204                                         PCI_DMA_BIDIRECTIONAL);
205
206                 if (chunk->nsg <= 0)
207                         goto fail;
208         }
209
210         return icm;
211
212 fail:
213         mthca_free_icm(dev, icm, coherent);
214         return NULL;
215 }
216
217 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
218 {
219         int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
220         int ret = 0;
221         u8 status;
222
223         mutex_lock(&table->mutex);
224
225         if (table->icm[i]) {
226                 ++table->icm[i]->refcount;
227                 goto out;
228         }
229
230         table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
231                                         (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
232                                         __GFP_NOWARN, table->coherent);
233         if (!table->icm[i]) {
234                 ret = -ENOMEM;
235                 goto out;
236         }
237
238         if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
239                           &status) || status) {
240                 mthca_free_icm(dev, table->icm[i], table->coherent);
241                 table->icm[i] = NULL;
242                 ret = -ENOMEM;
243                 goto out;
244         }
245
246         ++table->icm[i]->refcount;
247
248 out:
249         mutex_unlock(&table->mutex);
250         return ret;
251 }
252
253 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
254 {
255         int i;
256         u8 status;
257
258         if (!mthca_is_memfree(dev))
259                 return;
260
261         i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
262
263         mutex_lock(&table->mutex);
264
265         if (--table->icm[i]->refcount == 0) {
266                 mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
267                                 MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
268                                 &status);
269                 mthca_free_icm(dev, table->icm[i], table->coherent);
270                 table->icm[i] = NULL;
271         }
272
273         mutex_unlock(&table->mutex);
274 }
275
276 void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle)
277 {
278         int idx, offset, dma_offset, i;
279         struct mthca_icm_chunk *chunk;
280         struct mthca_icm *icm;
281         struct page *page = NULL;
282
283         if (!table->lowmem)
284                 return NULL;
285
286         mutex_lock(&table->mutex);
287
288         idx = (obj & (table->num_obj - 1)) * table->obj_size;
289         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
290         dma_offset = offset = idx % MTHCA_TABLE_CHUNK_SIZE;
291
292         if (!icm)
293                 goto out;
294
295         list_for_each_entry(chunk, &icm->chunk_list, list) {
296                 for (i = 0; i < chunk->npages; ++i) {
297                         if (dma_handle && dma_offset >= 0) {
298                                 if (sg_dma_len(&chunk->mem[i]) > dma_offset)
299                                         *dma_handle = sg_dma_address(&chunk->mem[i]) +
300                                                 dma_offset;
301                                 dma_offset -= sg_dma_len(&chunk->mem[i]);
302                         }
303                         /* DMA mapping can merge pages but not split them,
304                          * so if we found the page, dma_handle has already
305                          * been assigned to. */
306                         if (chunk->mem[i].length > offset) {
307                                 page = chunk->mem[i].page;
308                                 goto out;
309                         }
310                         offset -= chunk->mem[i].length;
311                 }
312         }
313
314 out:
315         mutex_unlock(&table->mutex);
316         return page ? lowmem_page_address(page) + offset : NULL;
317 }
318
319 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
320                           int start, int end)
321 {
322         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
323         int i, err;
324
325         for (i = start; i <= end; i += inc) {
326                 err = mthca_table_get(dev, table, i);
327                 if (err)
328                         goto fail;
329         }
330
331         return 0;
332
333 fail:
334         while (i > start) {
335                 i -= inc;
336                 mthca_table_put(dev, table, i);
337         }
338
339         return err;
340 }
341
342 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
343                            int start, int end)
344 {
345         int i;
346
347         if (!mthca_is_memfree(dev))
348                 return;
349
350         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
351                 mthca_table_put(dev, table, i);
352 }
353
354 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
355                                               u64 virt, int obj_size,
356                                               int nobj, int reserved,
357                                               int use_lowmem, int use_coherent)
358 {
359         struct mthca_icm_table *table;
360         int num_icm;
361         unsigned chunk_size;
362         int i;
363         u8 status;
364
365         num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
366
367         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
368         if (!table)
369                 return NULL;
370
371         table->virt     = virt;
372         table->num_icm  = num_icm;
373         table->num_obj  = nobj;
374         table->obj_size = obj_size;
375         table->lowmem   = use_lowmem;
376         table->coherent = use_coherent;
377         mutex_init(&table->mutex);
378
379         for (i = 0; i < num_icm; ++i)
380                 table->icm[i] = NULL;
381
382         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
383                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
384                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
385                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
386
387                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
388                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
389                                                 __GFP_NOWARN, use_coherent);
390                 if (!table->icm[i])
391                         goto err;
392                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
393                                   &status) || status) {
394                         mthca_free_icm(dev, table->icm[i], table->coherent);
395                         table->icm[i] = NULL;
396                         goto err;
397                 }
398
399                 /*
400                  * Add a reference to this ICM chunk so that it never
401                  * gets freed (since it contains reserved firmware objects).
402                  */
403                 ++table->icm[i]->refcount;
404         }
405
406         return table;
407
408 err:
409         for (i = 0; i < num_icm; ++i)
410                 if (table->icm[i]) {
411                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
412                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
413                                         &status);
414                         mthca_free_icm(dev, table->icm[i], table->coherent);
415                 }
416
417         kfree(table);
418
419         return NULL;
420 }
421
422 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
423 {
424         int i;
425         u8 status;
426
427         for (i = 0; i < table->num_icm; ++i)
428                 if (table->icm[i]) {
429                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
430                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
431                                         &status);
432                         mthca_free_icm(dev, table->icm[i], table->coherent);
433                 }
434
435         kfree(table);
436 }
437
438 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
439 {
440         return dev->uar_table.uarc_base +
441                 uar->index * dev->uar_table.uarc_size +
442                 page * MTHCA_ICM_PAGE_SIZE;
443 }
444
445 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
446                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
447 {
448         int ret = 0;
449         u8 status;
450         int i;
451
452         if (!mthca_is_memfree(dev))
453                 return 0;
454
455         if (index < 0 || index > dev->uar_table.uarc_size / 8)
456                 return -EINVAL;
457
458         mutex_lock(&db_tab->mutex);
459
460         i = index / MTHCA_DB_REC_PER_PAGE;
461
462         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
463             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
464             (uaddr & 4095)) {
465                 ret = -EINVAL;
466                 goto out;
467         }
468
469         if (db_tab->page[i].refcount) {
470                 ++db_tab->page[i].refcount;
471                 goto out;
472         }
473
474         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
475                              &db_tab->page[i].mem.page, NULL);
476         if (ret < 0)
477                 goto out;
478
479         db_tab->page[i].mem.length = MTHCA_ICM_PAGE_SIZE;
480         db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
481
482         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
483         if (ret < 0) {
484                 put_page(db_tab->page[i].mem.page);
485                 goto out;
486         }
487
488         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
489                                  mthca_uarc_virt(dev, uar, i), &status);
490         if (!ret && status)
491                 ret = -EINVAL;
492         if (ret) {
493                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
494                 put_page(db_tab->page[i].mem.page);
495                 goto out;
496         }
497
498         db_tab->page[i].uvirt    = uaddr;
499         db_tab->page[i].refcount = 1;
500
501 out:
502         mutex_unlock(&db_tab->mutex);
503         return ret;
504 }
505
506 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
507                          struct mthca_user_db_table *db_tab, int index)
508 {
509         if (!mthca_is_memfree(dev))
510                 return;
511
512         /*
513          * To make our bookkeeping simpler, we don't unmap DB
514          * pages until we clean up the whole db table.
515          */
516
517         mutex_lock(&db_tab->mutex);
518
519         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
520
521         mutex_unlock(&db_tab->mutex);
522 }
523
524 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
525 {
526         struct mthca_user_db_table *db_tab;
527         int npages;
528         int i;
529
530         if (!mthca_is_memfree(dev))
531                 return NULL;
532
533         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
534         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
535         if (!db_tab)
536                 return ERR_PTR(-ENOMEM);
537
538         mutex_init(&db_tab->mutex);
539         for (i = 0; i < npages; ++i) {
540                 db_tab->page[i].refcount = 0;
541                 db_tab->page[i].uvirt    = 0;
542         }
543
544         return db_tab;
545 }
546
547 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
548                                struct mthca_user_db_table *db_tab)
549 {
550         int i;
551         u8 status;
552
553         if (!mthca_is_memfree(dev))
554                 return;
555
556         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
557                 if (db_tab->page[i].uvirt) {
558                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
559                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
560                         put_page(db_tab->page[i].mem.page);
561                 }
562         }
563
564         kfree(db_tab);
565 }
566
567 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
568                    u32 qn, __be32 **db)
569 {
570         int group;
571         int start, end, dir;
572         int i, j;
573         struct mthca_db_page *page;
574         int ret = 0;
575         u8 status;
576
577         mutex_lock(&dev->db_tab->mutex);
578
579         switch (type) {
580         case MTHCA_DB_TYPE_CQ_ARM:
581         case MTHCA_DB_TYPE_SQ:
582                 group = 0;
583                 start = 0;
584                 end   = dev->db_tab->max_group1;
585                 dir   = 1;
586                 break;
587
588         case MTHCA_DB_TYPE_CQ_SET_CI:
589         case MTHCA_DB_TYPE_RQ:
590         case MTHCA_DB_TYPE_SRQ:
591                 group = 1;
592                 start = dev->db_tab->npages - 1;
593                 end   = dev->db_tab->min_group2;
594                 dir   = -1;
595                 break;
596
597         default:
598                 ret = -EINVAL;
599                 goto out;
600         }
601
602         for (i = start; i != end; i += dir)
603                 if (dev->db_tab->page[i].db_rec &&
604                     !bitmap_full(dev->db_tab->page[i].used,
605                                  MTHCA_DB_REC_PER_PAGE)) {
606                         page = dev->db_tab->page + i;
607                         goto found;
608                 }
609
610         for (i = start; i != end; i += dir)
611                 if (!dev->db_tab->page[i].db_rec) {
612                         page = dev->db_tab->page + i;
613                         goto alloc;
614                 }
615
616         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
617                 ret = -ENOMEM;
618                 goto out;
619         }
620
621         if (group == 0)
622                 ++dev->db_tab->max_group1;
623         else
624                 --dev->db_tab->min_group2;
625
626         page = dev->db_tab->page + end;
627
628 alloc:
629         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
630                                           &page->mapping, GFP_KERNEL);
631         if (!page->db_rec) {
632                 ret = -ENOMEM;
633                 goto out;
634         }
635         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
636
637         ret = mthca_MAP_ICM_page(dev, page->mapping,
638                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
639         if (!ret && status)
640                 ret = -EINVAL;
641         if (ret) {
642                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
643                                   page->db_rec, page->mapping);
644                 goto out;
645         }
646
647         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
648
649 found:
650         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
651         set_bit(j, page->used);
652
653         if (group == 1)
654                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
655
656         ret = i * MTHCA_DB_REC_PER_PAGE + j;
657
658         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
659
660         *db = (__be32 *) &page->db_rec[j];
661
662 out:
663         mutex_unlock(&dev->db_tab->mutex);
664
665         return ret;
666 }
667
668 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
669 {
670         int i, j;
671         struct mthca_db_page *page;
672         u8 status;
673
674         i = db_index / MTHCA_DB_REC_PER_PAGE;
675         j = db_index % MTHCA_DB_REC_PER_PAGE;
676
677         page = dev->db_tab->page + i;
678
679         mutex_lock(&dev->db_tab->mutex);
680
681         page->db_rec[j] = 0;
682         if (i >= dev->db_tab->min_group2)
683                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
684         clear_bit(j, page->used);
685
686         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
687             i >= dev->db_tab->max_group1 - 1) {
688                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
689
690                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
691                                   page->db_rec, page->mapping);
692                 page->db_rec = NULL;
693
694                 if (i == dev->db_tab->max_group1) {
695                         --dev->db_tab->max_group1;
696                         /* XXX may be able to unmap more pages now */
697                 }
698                 if (i == dev->db_tab->min_group2)
699                         ++dev->db_tab->min_group2;
700         }
701
702         mutex_unlock(&dev->db_tab->mutex);
703 }
704
705 int mthca_init_db_tab(struct mthca_dev *dev)
706 {
707         int i;
708
709         if (!mthca_is_memfree(dev))
710                 return 0;
711
712         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
713         if (!dev->db_tab)
714                 return -ENOMEM;
715
716         mutex_init(&dev->db_tab->mutex);
717
718         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
719         dev->db_tab->max_group1 = 0;
720         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
721
722         dev->db_tab->page = kmalloc(dev->db_tab->npages *
723                                     sizeof *dev->db_tab->page,
724                                     GFP_KERNEL);
725         if (!dev->db_tab->page) {
726                 kfree(dev->db_tab);
727                 return -ENOMEM;
728         }
729
730         for (i = 0; i < dev->db_tab->npages; ++i)
731                 dev->db_tab->page[i].db_rec = NULL;
732
733         return 0;
734 }
735
736 void mthca_cleanup_db_tab(struct mthca_dev *dev)
737 {
738         int i;
739         u8 status;
740
741         if (!mthca_is_memfree(dev))
742                 return;
743
744         /*
745          * Because we don't always free our UARC pages when they
746          * become empty to make mthca_free_db() simpler we need to
747          * make a sweep through the doorbell pages and free any
748          * leftover pages now.
749          */
750         for (i = 0; i < dev->db_tab->npages; ++i) {
751                 if (!dev->db_tab->page[i].db_rec)
752                         continue;
753
754                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
755                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
756
757                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
758
759                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
760                                   dev->db_tab->page[i].db_rec,
761                                   dev->db_tab->page[i].mapping);
762         }
763
764         kfree(dev->db_tab->page);
765         kfree(dev->db_tab);
766 }