Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
[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
35 #include <linux/mm.h>
36 #include <linux/scatterlist.h>
37 #include <linux/sched.h>
38
39 #include <asm/page.h>
40
41 #include "mthca_memfree.h"
42 #include "mthca_dev.h"
43 #include "mthca_cmd.h"
44
45 /*
46  * We allocate in as big chunks as we can, up to a maximum of 256 KB
47  * per chunk.
48  */
49 enum {
50         MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
51         MTHCA_TABLE_CHUNK_SIZE = 1 << 18
52 };
53
54 struct mthca_user_db_table {
55         struct mutex mutex;
56         struct {
57                 u64                uvirt;
58                 struct scatterlist mem;
59                 int                refcount;
60         }                page[0];
61 };
62
63 static void mthca_free_icm_pages(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
64 {
65         int i;
66
67         if (chunk->nsg > 0)
68                 pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
69                              PCI_DMA_BIDIRECTIONAL);
70
71         for (i = 0; i < chunk->npages; ++i)
72                 __free_pages(sg_page(&chunk->mem[i]),
73                              get_order(chunk->mem[i].length));
74 }
75
76 static void mthca_free_icm_coherent(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
77 {
78         int i;
79
80         for (i = 0; i < chunk->npages; ++i) {
81                 dma_free_coherent(&dev->pdev->dev, chunk->mem[i].length,
82                                   lowmem_page_address(sg_page(&chunk->mem[i])),
83                                   sg_dma_address(&chunk->mem[i]));
84         }
85 }
86
87 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent)
88 {
89         struct mthca_icm_chunk *chunk, *tmp;
90
91         if (!icm)
92                 return;
93
94         list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
95                 if (coherent)
96                         mthca_free_icm_coherent(dev, chunk);
97                 else
98                         mthca_free_icm_pages(dev, chunk);
99
100                 kfree(chunk);
101         }
102
103         kfree(icm);
104 }
105
106 static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
107 {
108         struct page *page;
109
110         /*
111          * Use __GFP_ZERO because buggy firmware assumes ICM pages are
112          * cleared, and subtle failures are seen if they aren't.
113          */
114         page = alloc_pages(gfp_mask | __GFP_ZERO, order);
115         if (!page)
116                 return -ENOMEM;
117
118         sg_set_page(mem, page, PAGE_SIZE << order, 0);
119         return 0;
120 }
121
122 static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
123                                     int order, gfp_t gfp_mask)
124 {
125         void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
126                                        gfp_mask);
127         if (!buf)
128                 return -ENOMEM;
129
130         sg_set_buf(mem, buf, PAGE_SIZE << order);
131         BUG_ON(mem->offset);
132         sg_dma_len(mem) = PAGE_SIZE << order;
133         return 0;
134 }
135
136 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
137                                   gfp_t gfp_mask, int coherent)
138 {
139         struct mthca_icm *icm;
140         struct mthca_icm_chunk *chunk = NULL;
141         int cur_order;
142         int ret;
143
144         /* We use sg_set_buf for coherent allocs, which assumes low memory */
145         BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));
146
147         icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
148         if (!icm)
149                 return icm;
150
151         icm->refcount = 0;
152         INIT_LIST_HEAD(&icm->chunk_list);
153
154         cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
155
156         while (npages > 0) {
157                 if (!chunk) {
158                         chunk = kmalloc(sizeof *chunk,
159                                         gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
160                         if (!chunk)
161                                 goto fail;
162
163                         sg_init_table(chunk->mem, MTHCA_ICM_CHUNK_LEN);
164                         chunk->npages = 0;
165                         chunk->nsg    = 0;
166                         list_add_tail(&chunk->list, &icm->chunk_list);
167                 }
168
169                 while (1 << cur_order > npages)
170                         --cur_order;
171
172                 if (coherent)
173                         ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
174                                                        &chunk->mem[chunk->npages],
175                                                        cur_order, gfp_mask);
176                 else
177                         ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
178                                                     cur_order, gfp_mask);
179
180                 if (!ret) {
181                         ++chunk->npages;
182
183                         if (coherent)
184                                 ++chunk->nsg;
185                         else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
186                                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
187                                                         chunk->npages,
188                                                         PCI_DMA_BIDIRECTIONAL);
189
190                                 if (chunk->nsg <= 0)
191                                         goto fail;
192                         }
193
194                         if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
195                                 chunk = NULL;
196
197                         npages -= 1 << cur_order;
198                 } else {
199                         --cur_order;
200                         if (cur_order < 0)
201                                 goto fail;
202                 }
203         }
204
205         if (!coherent && chunk) {
206                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
207                                         chunk->npages,
208                                         PCI_DMA_BIDIRECTIONAL);
209
210                 if (chunk->nsg <= 0)
211                         goto fail;
212         }
213
214         return icm;
215
216 fail:
217         mthca_free_icm(dev, icm, coherent);
218         return NULL;
219 }
220
221 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
222 {
223         int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
224         int ret = 0;
225         u8 status;
226
227         mutex_lock(&table->mutex);
228
229         if (table->icm[i]) {
230                 ++table->icm[i]->refcount;
231                 goto out;
232         }
233
234         table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
235                                         (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
236                                         __GFP_NOWARN, table->coherent);
237         if (!table->icm[i]) {
238                 ret = -ENOMEM;
239                 goto out;
240         }
241
242         if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
243                           &status) || status) {
244                 mthca_free_icm(dev, table->icm[i], table->coherent);
245                 table->icm[i] = NULL;
246                 ret = -ENOMEM;
247                 goto out;
248         }
249
250         ++table->icm[i]->refcount;
251
252 out:
253         mutex_unlock(&table->mutex);
254         return ret;
255 }
256
257 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
258 {
259         int i;
260         u8 status;
261
262         if (!mthca_is_memfree(dev))
263                 return;
264
265         i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
266
267         mutex_lock(&table->mutex);
268
269         if (--table->icm[i]->refcount == 0) {
270                 mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
271                                 MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
272                                 &status);
273                 mthca_free_icm(dev, table->icm[i], table->coherent);
274                 table->icm[i] = NULL;
275         }
276
277         mutex_unlock(&table->mutex);
278 }
279
280 void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle)
281 {
282         int idx, offset, dma_offset, i;
283         struct mthca_icm_chunk *chunk;
284         struct mthca_icm *icm;
285         struct page *page = NULL;
286
287         if (!table->lowmem)
288                 return NULL;
289
290         mutex_lock(&table->mutex);
291
292         idx = (obj & (table->num_obj - 1)) * table->obj_size;
293         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
294         dma_offset = offset = idx % MTHCA_TABLE_CHUNK_SIZE;
295
296         if (!icm)
297                 goto out;
298
299         list_for_each_entry(chunk, &icm->chunk_list, list) {
300                 for (i = 0; i < chunk->npages; ++i) {
301                         if (dma_handle && dma_offset >= 0) {
302                                 if (sg_dma_len(&chunk->mem[i]) > dma_offset)
303                                         *dma_handle = sg_dma_address(&chunk->mem[i]) +
304                                                 dma_offset;
305                                 dma_offset -= sg_dma_len(&chunk->mem[i]);
306                         }
307                         /* DMA mapping can merge pages but not split them,
308                          * so if we found the page, dma_handle has already
309                          * been assigned to. */
310                         if (chunk->mem[i].length > offset) {
311                                 page = sg_page(&chunk->mem[i]);
312                                 goto out;
313                         }
314                         offset -= chunk->mem[i].length;
315                 }
316         }
317
318 out:
319         mutex_unlock(&table->mutex);
320         return page ? lowmem_page_address(page) + offset : NULL;
321 }
322
323 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
324                           int start, int end)
325 {
326         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
327         int i, err;
328
329         for (i = start; i <= end; i += inc) {
330                 err = mthca_table_get(dev, table, i);
331                 if (err)
332                         goto fail;
333         }
334
335         return 0;
336
337 fail:
338         while (i > start) {
339                 i -= inc;
340                 mthca_table_put(dev, table, i);
341         }
342
343         return err;
344 }
345
346 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
347                            int start, int end)
348 {
349         int i;
350
351         if (!mthca_is_memfree(dev))
352                 return;
353
354         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
355                 mthca_table_put(dev, table, i);
356 }
357
358 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
359                                               u64 virt, int obj_size,
360                                               int nobj, int reserved,
361                                               int use_lowmem, int use_coherent)
362 {
363         struct mthca_icm_table *table;
364         int obj_per_chunk;
365         int num_icm;
366         unsigned chunk_size;
367         int i;
368         u8 status;
369
370         obj_per_chunk = MTHCA_TABLE_CHUNK_SIZE / obj_size;
371         num_icm = DIV_ROUND_UP(nobj, obj_per_chunk);
372
373         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
374         if (!table)
375                 return NULL;
376
377         table->virt     = virt;
378         table->num_icm  = num_icm;
379         table->num_obj  = nobj;
380         table->obj_size = obj_size;
381         table->lowmem   = use_lowmem;
382         table->coherent = use_coherent;
383         mutex_init(&table->mutex);
384
385         for (i = 0; i < num_icm; ++i)
386                 table->icm[i] = NULL;
387
388         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
389                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
390                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
391                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
392
393                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
394                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
395                                                 __GFP_NOWARN, use_coherent);
396                 if (!table->icm[i])
397                         goto err;
398                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
399                                   &status) || status) {
400                         mthca_free_icm(dev, table->icm[i], table->coherent);
401                         table->icm[i] = NULL;
402                         goto err;
403                 }
404
405                 /*
406                  * Add a reference to this ICM chunk so that it never
407                  * gets freed (since it contains reserved firmware objects).
408                  */
409                 ++table->icm[i]->refcount;
410         }
411
412         return table;
413
414 err:
415         for (i = 0; i < num_icm; ++i)
416                 if (table->icm[i]) {
417                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
418                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
419                                         &status);
420                         mthca_free_icm(dev, table->icm[i], table->coherent);
421                 }
422
423         kfree(table);
424
425         return NULL;
426 }
427
428 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
429 {
430         int i;
431         u8 status;
432
433         for (i = 0; i < table->num_icm; ++i)
434                 if (table->icm[i]) {
435                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
436                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
437                                         &status);
438                         mthca_free_icm(dev, table->icm[i], table->coherent);
439                 }
440
441         kfree(table);
442 }
443
444 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
445 {
446         return dev->uar_table.uarc_base +
447                 uar->index * dev->uar_table.uarc_size +
448                 page * MTHCA_ICM_PAGE_SIZE;
449 }
450
451 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
452                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
453 {
454         struct page *pages[1];
455         int ret = 0;
456         u8 status;
457         int i;
458
459         if (!mthca_is_memfree(dev))
460                 return 0;
461
462         if (index < 0 || index > dev->uar_table.uarc_size / 8)
463                 return -EINVAL;
464
465         mutex_lock(&db_tab->mutex);
466
467         i = index / MTHCA_DB_REC_PER_PAGE;
468
469         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
470             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
471             (uaddr & 4095)) {
472                 ret = -EINVAL;
473                 goto out;
474         }
475
476         if (db_tab->page[i].refcount) {
477                 ++db_tab->page[i].refcount;
478                 goto out;
479         }
480
481         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
482                              pages, NULL);
483         if (ret < 0)
484                 goto out;
485
486         sg_set_page(&db_tab->page[i].mem, pages[0], MTHCA_ICM_PAGE_SIZE,
487                         uaddr & ~PAGE_MASK);
488
489         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
490         if (ret < 0) {
491                 put_page(pages[0]);
492                 goto out;
493         }
494
495         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
496                                  mthca_uarc_virt(dev, uar, i), &status);
497         if (!ret && status)
498                 ret = -EINVAL;
499         if (ret) {
500                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
501                 put_page(sg_page(&db_tab->page[i].mem));
502                 goto out;
503         }
504
505         db_tab->page[i].uvirt    = uaddr;
506         db_tab->page[i].refcount = 1;
507
508 out:
509         mutex_unlock(&db_tab->mutex);
510         return ret;
511 }
512
513 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
514                          struct mthca_user_db_table *db_tab, int index)
515 {
516         if (!mthca_is_memfree(dev))
517                 return;
518
519         /*
520          * To make our bookkeeping simpler, we don't unmap DB
521          * pages until we clean up the whole db table.
522          */
523
524         mutex_lock(&db_tab->mutex);
525
526         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
527
528         mutex_unlock(&db_tab->mutex);
529 }
530
531 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
532 {
533         struct mthca_user_db_table *db_tab;
534         int npages;
535         int i;
536
537         if (!mthca_is_memfree(dev))
538                 return NULL;
539
540         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
541         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
542         if (!db_tab)
543                 return ERR_PTR(-ENOMEM);
544
545         mutex_init(&db_tab->mutex);
546         for (i = 0; i < npages; ++i) {
547                 db_tab->page[i].refcount = 0;
548                 db_tab->page[i].uvirt    = 0;
549                 sg_init_table(&db_tab->page[i].mem, 1);
550         }
551
552         return db_tab;
553 }
554
555 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
556                                struct mthca_user_db_table *db_tab)
557 {
558         int i;
559         u8 status;
560
561         if (!mthca_is_memfree(dev))
562                 return;
563
564         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
565                 if (db_tab->page[i].uvirt) {
566                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
567                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
568                         put_page(sg_page(&db_tab->page[i].mem));
569                 }
570         }
571
572         kfree(db_tab);
573 }
574
575 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
576                    u32 qn, __be32 **db)
577 {
578         int group;
579         int start, end, dir;
580         int i, j;
581         struct mthca_db_page *page;
582         int ret = 0;
583         u8 status;
584
585         mutex_lock(&dev->db_tab->mutex);
586
587         switch (type) {
588         case MTHCA_DB_TYPE_CQ_ARM:
589         case MTHCA_DB_TYPE_SQ:
590                 group = 0;
591                 start = 0;
592                 end   = dev->db_tab->max_group1;
593                 dir   = 1;
594                 break;
595
596         case MTHCA_DB_TYPE_CQ_SET_CI:
597         case MTHCA_DB_TYPE_RQ:
598         case MTHCA_DB_TYPE_SRQ:
599                 group = 1;
600                 start = dev->db_tab->npages - 1;
601                 end   = dev->db_tab->min_group2;
602                 dir   = -1;
603                 break;
604
605         default:
606                 ret = -EINVAL;
607                 goto out;
608         }
609
610         for (i = start; i != end; i += dir)
611                 if (dev->db_tab->page[i].db_rec &&
612                     !bitmap_full(dev->db_tab->page[i].used,
613                                  MTHCA_DB_REC_PER_PAGE)) {
614                         page = dev->db_tab->page + i;
615                         goto found;
616                 }
617
618         for (i = start; i != end; i += dir)
619                 if (!dev->db_tab->page[i].db_rec) {
620                         page = dev->db_tab->page + i;
621                         goto alloc;
622                 }
623
624         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
625                 ret = -ENOMEM;
626                 goto out;
627         }
628
629         if (group == 0)
630                 ++dev->db_tab->max_group1;
631         else
632                 --dev->db_tab->min_group2;
633
634         page = dev->db_tab->page + end;
635
636 alloc:
637         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
638                                           &page->mapping, GFP_KERNEL);
639         if (!page->db_rec) {
640                 ret = -ENOMEM;
641                 goto out;
642         }
643         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
644
645         ret = mthca_MAP_ICM_page(dev, page->mapping,
646                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
647         if (!ret && status)
648                 ret = -EINVAL;
649         if (ret) {
650                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
651                                   page->db_rec, page->mapping);
652                 goto out;
653         }
654
655         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
656
657 found:
658         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
659         set_bit(j, page->used);
660
661         if (group == 1)
662                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
663
664         ret = i * MTHCA_DB_REC_PER_PAGE + j;
665
666         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
667
668         *db = (__be32 *) &page->db_rec[j];
669
670 out:
671         mutex_unlock(&dev->db_tab->mutex);
672
673         return ret;
674 }
675
676 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
677 {
678         int i, j;
679         struct mthca_db_page *page;
680         u8 status;
681
682         i = db_index / MTHCA_DB_REC_PER_PAGE;
683         j = db_index % MTHCA_DB_REC_PER_PAGE;
684
685         page = dev->db_tab->page + i;
686
687         mutex_lock(&dev->db_tab->mutex);
688
689         page->db_rec[j] = 0;
690         if (i >= dev->db_tab->min_group2)
691                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
692         clear_bit(j, page->used);
693
694         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
695             i >= dev->db_tab->max_group1 - 1) {
696                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
697
698                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
699                                   page->db_rec, page->mapping);
700                 page->db_rec = NULL;
701
702                 if (i == dev->db_tab->max_group1) {
703                         --dev->db_tab->max_group1;
704                         /* XXX may be able to unmap more pages now */
705                 }
706                 if (i == dev->db_tab->min_group2)
707                         ++dev->db_tab->min_group2;
708         }
709
710         mutex_unlock(&dev->db_tab->mutex);
711 }
712
713 int mthca_init_db_tab(struct mthca_dev *dev)
714 {
715         int i;
716
717         if (!mthca_is_memfree(dev))
718                 return 0;
719
720         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
721         if (!dev->db_tab)
722                 return -ENOMEM;
723
724         mutex_init(&dev->db_tab->mutex);
725
726         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
727         dev->db_tab->max_group1 = 0;
728         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
729
730         dev->db_tab->page = kmalloc(dev->db_tab->npages *
731                                     sizeof *dev->db_tab->page,
732                                     GFP_KERNEL);
733         if (!dev->db_tab->page) {
734                 kfree(dev->db_tab);
735                 return -ENOMEM;
736         }
737
738         for (i = 0; i < dev->db_tab->npages; ++i)
739                 dev->db_tab->page[i].db_rec = NULL;
740
741         return 0;
742 }
743
744 void mthca_cleanup_db_tab(struct mthca_dev *dev)
745 {
746         int i;
747         u8 status;
748
749         if (!mthca_is_memfree(dev))
750                 return;
751
752         /*
753          * Because we don't always free our UARC pages when they
754          * become empty to make mthca_free_db() simpler we need to
755          * make a sweep through the doorbell pages and free any
756          * leftover pages now.
757          */
758         for (i = 0; i < dev->db_tab->npages; ++i) {
759                 if (!dev->db_tab->page[i].db_rec)
760                         continue;
761
762                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
763                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
764
765                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
766
767                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
768                                   dev->db_tab->page[i].db_rec,
769                                   dev->db_tab->page[i].mapping);
770         }
771
772         kfree(dev->db_tab->page);
773         kfree(dev->db_tab);
774 }