RDS: fold rdma.h into rds.h
[linux-3.10.git] / net / rds / ib_rdma.c
1 /*
2  * Copyright (c) 2006 Oracle.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35
36 #include "rds.h"
37 #include "ib.h"
38
39
40 /*
41  * This is stored as mr->r_trans_private.
42  */
43 struct rds_ib_mr {
44         struct rds_ib_device    *device;
45         struct rds_ib_mr_pool   *pool;
46         struct ib_fmr           *fmr;
47         struct list_head        list;
48         unsigned int            remap_count;
49
50         struct scatterlist      *sg;
51         unsigned int            sg_len;
52         u64                     *dma;
53         int                     sg_dma_len;
54 };
55
56 /*
57  * Our own little FMR pool
58  */
59 struct rds_ib_mr_pool {
60         struct mutex            flush_lock;             /* serialize fmr invalidate */
61         struct work_struct      flush_worker;           /* flush worker */
62
63         spinlock_t              list_lock;              /* protect variables below */
64         atomic_t                item_count;             /* total # of MRs */
65         atomic_t                dirty_count;            /* # dirty of MRs */
66         struct list_head        drop_list;              /* MRs that have reached their max_maps limit */
67         struct list_head        free_list;              /* unused MRs */
68         struct list_head        clean_list;             /* unused & unamapped MRs */
69         atomic_t                free_pinned;            /* memory pinned by free MRs */
70         unsigned long           max_items;
71         unsigned long           max_items_soft;
72         unsigned long           max_free_pinned;
73         struct ib_fmr_attr      fmr_attr;
74 };
75
76 static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all);
77 static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr);
78 static void rds_ib_mr_pool_flush_worker(struct work_struct *work);
79
80 static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
81 {
82         struct rds_ib_device *rds_ibdev;
83         struct rds_ib_ipaddr *i_ipaddr;
84
85         list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
86                 spin_lock_irq(&rds_ibdev->spinlock);
87                 list_for_each_entry(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
88                         if (i_ipaddr->ipaddr == ipaddr) {
89                                 spin_unlock_irq(&rds_ibdev->spinlock);
90                                 return rds_ibdev;
91                         }
92                 }
93                 spin_unlock_irq(&rds_ibdev->spinlock);
94         }
95
96         return NULL;
97 }
98
99 static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
100 {
101         struct rds_ib_ipaddr *i_ipaddr;
102
103         i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
104         if (!i_ipaddr)
105                 return -ENOMEM;
106
107         i_ipaddr->ipaddr = ipaddr;
108
109         spin_lock_irq(&rds_ibdev->spinlock);
110         list_add_tail(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
111         spin_unlock_irq(&rds_ibdev->spinlock);
112
113         return 0;
114 }
115
116 static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
117 {
118         struct rds_ib_ipaddr *i_ipaddr, *next;
119
120         spin_lock_irq(&rds_ibdev->spinlock);
121         list_for_each_entry_safe(i_ipaddr, next, &rds_ibdev->ipaddr_list, list) {
122                 if (i_ipaddr->ipaddr == ipaddr) {
123                         list_del(&i_ipaddr->list);
124                         kfree(i_ipaddr);
125                         break;
126                 }
127         }
128         spin_unlock_irq(&rds_ibdev->spinlock);
129 }
130
131 int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
132 {
133         struct rds_ib_device *rds_ibdev_old;
134
135         rds_ibdev_old = rds_ib_get_device(ipaddr);
136         if (rds_ibdev_old)
137                 rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
138
139         return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
140 }
141
142 void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
143 {
144         struct rds_ib_connection *ic = conn->c_transport_data;
145
146         /* conn was previously on the nodev_conns_list */
147         spin_lock_irq(&ib_nodev_conns_lock);
148         BUG_ON(list_empty(&ib_nodev_conns));
149         BUG_ON(list_empty(&ic->ib_node));
150         list_del(&ic->ib_node);
151
152         spin_lock_irq(&rds_ibdev->spinlock);
153         list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
154         spin_unlock_irq(&rds_ibdev->spinlock);
155         spin_unlock_irq(&ib_nodev_conns_lock);
156
157         ic->rds_ibdev = rds_ibdev;
158 }
159
160 void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
161 {
162         struct rds_ib_connection *ic = conn->c_transport_data;
163
164         /* place conn on nodev_conns_list */
165         spin_lock(&ib_nodev_conns_lock);
166
167         spin_lock_irq(&rds_ibdev->spinlock);
168         BUG_ON(list_empty(&ic->ib_node));
169         list_del(&ic->ib_node);
170         spin_unlock_irq(&rds_ibdev->spinlock);
171
172         list_add_tail(&ic->ib_node, &ib_nodev_conns);
173
174         spin_unlock(&ib_nodev_conns_lock);
175
176         ic->rds_ibdev = NULL;
177 }
178
179 void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock)
180 {
181         struct rds_ib_connection *ic, *_ic;
182         LIST_HEAD(tmp_list);
183
184         /* avoid calling conn_destroy with irqs off */
185         spin_lock_irq(list_lock);
186         list_splice(list, &tmp_list);
187         INIT_LIST_HEAD(list);
188         spin_unlock_irq(list_lock);
189
190         list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
191                 rds_conn_destroy(ic->conn);
192 }
193
194 struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev)
195 {
196         struct rds_ib_mr_pool *pool;
197
198         pool = kzalloc(sizeof(*pool), GFP_KERNEL);
199         if (!pool)
200                 return ERR_PTR(-ENOMEM);
201
202         INIT_LIST_HEAD(&pool->free_list);
203         INIT_LIST_HEAD(&pool->drop_list);
204         INIT_LIST_HEAD(&pool->clean_list);
205         mutex_init(&pool->flush_lock);
206         spin_lock_init(&pool->list_lock);
207         INIT_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
208
209         pool->fmr_attr.max_pages = fmr_message_size;
210         pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
211         pool->fmr_attr.page_shift = PAGE_SHIFT;
212         pool->max_free_pinned = rds_ibdev->max_fmrs * fmr_message_size / 4;
213
214         /* We never allow more than max_items MRs to be allocated.
215          * When we exceed more than max_items_soft, we start freeing
216          * items more aggressively.
217          * Make sure that max_items > max_items_soft > max_items / 2
218          */
219         pool->max_items_soft = rds_ibdev->max_fmrs * 3 / 4;
220         pool->max_items = rds_ibdev->max_fmrs;
221
222         return pool;
223 }
224
225 void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
226 {
227         struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
228
229         iinfo->rdma_mr_max = pool->max_items;
230         iinfo->rdma_mr_size = pool->fmr_attr.max_pages;
231 }
232
233 void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
234 {
235         flush_workqueue(rds_wq);
236         rds_ib_flush_mr_pool(pool, 1);
237         WARN_ON(atomic_read(&pool->item_count));
238         WARN_ON(atomic_read(&pool->free_pinned));
239         kfree(pool);
240 }
241
242 static inline struct rds_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool)
243 {
244         struct rds_ib_mr *ibmr = NULL;
245         unsigned long flags;
246
247         spin_lock_irqsave(&pool->list_lock, flags);
248         if (!list_empty(&pool->clean_list)) {
249                 ibmr = list_entry(pool->clean_list.next, struct rds_ib_mr, list);
250                 list_del_init(&ibmr->list);
251         }
252         spin_unlock_irqrestore(&pool->list_lock, flags);
253
254         return ibmr;
255 }
256
257 static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev)
258 {
259         struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
260         struct rds_ib_mr *ibmr = NULL;
261         int err = 0, iter = 0;
262
263         while (1) {
264                 ibmr = rds_ib_reuse_fmr(pool);
265                 if (ibmr)
266                         return ibmr;
267
268                 /* No clean MRs - now we have the choice of either
269                  * allocating a fresh MR up to the limit imposed by the
270                  * driver, or flush any dirty unused MRs.
271                  * We try to avoid stalling in the send path if possible,
272                  * so we allocate as long as we're allowed to.
273                  *
274                  * We're fussy with enforcing the FMR limit, though. If the driver
275                  * tells us we can't use more than N fmrs, we shouldn't start
276                  * arguing with it */
277                 if (atomic_inc_return(&pool->item_count) <= pool->max_items)
278                         break;
279
280                 atomic_dec(&pool->item_count);
281
282                 if (++iter > 2) {
283                         rds_ib_stats_inc(s_ib_rdma_mr_pool_depleted);
284                         return ERR_PTR(-EAGAIN);
285                 }
286
287                 /* We do have some empty MRs. Flush them out. */
288                 rds_ib_stats_inc(s_ib_rdma_mr_pool_wait);
289                 rds_ib_flush_mr_pool(pool, 0);
290         }
291
292         ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
293         if (!ibmr) {
294                 err = -ENOMEM;
295                 goto out_no_cigar;
296         }
297
298         ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
299                         (IB_ACCESS_LOCAL_WRITE |
300                          IB_ACCESS_REMOTE_READ |
301                          IB_ACCESS_REMOTE_WRITE),
302                         &pool->fmr_attr);
303         if (IS_ERR(ibmr->fmr)) {
304                 err = PTR_ERR(ibmr->fmr);
305                 ibmr->fmr = NULL;
306                 printk(KERN_WARNING "RDS/IB: ib_alloc_fmr failed (err=%d)\n", err);
307                 goto out_no_cigar;
308         }
309
310         rds_ib_stats_inc(s_ib_rdma_mr_alloc);
311         return ibmr;
312
313 out_no_cigar:
314         if (ibmr) {
315                 if (ibmr->fmr)
316                         ib_dealloc_fmr(ibmr->fmr);
317                 kfree(ibmr);
318         }
319         atomic_dec(&pool->item_count);
320         return ERR_PTR(err);
321 }
322
323 static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
324                struct scatterlist *sg, unsigned int nents)
325 {
326         struct ib_device *dev = rds_ibdev->dev;
327         struct scatterlist *scat = sg;
328         u64 io_addr = 0;
329         u64 *dma_pages;
330         u32 len;
331         int page_cnt, sg_dma_len;
332         int i, j;
333         int ret;
334
335         sg_dma_len = ib_dma_map_sg(dev, sg, nents,
336                                  DMA_BIDIRECTIONAL);
337         if (unlikely(!sg_dma_len)) {
338                 printk(KERN_WARNING "RDS/IB: dma_map_sg failed!\n");
339                 return -EBUSY;
340         }
341
342         len = 0;
343         page_cnt = 0;
344
345         for (i = 0; i < sg_dma_len; ++i) {
346                 unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
347                 u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
348
349                 if (dma_addr & ~PAGE_MASK) {
350                         if (i > 0)
351                                 return -EINVAL;
352                         else
353                                 ++page_cnt;
354                 }
355                 if ((dma_addr + dma_len) & ~PAGE_MASK) {
356                         if (i < sg_dma_len - 1)
357                                 return -EINVAL;
358                         else
359                                 ++page_cnt;
360                 }
361
362                 len += dma_len;
363         }
364
365         page_cnt += len >> PAGE_SHIFT;
366         if (page_cnt > fmr_message_size)
367                 return -EINVAL;
368
369         dma_pages = kmalloc(sizeof(u64) * page_cnt, GFP_ATOMIC);
370         if (!dma_pages)
371                 return -ENOMEM;
372
373         page_cnt = 0;
374         for (i = 0; i < sg_dma_len; ++i) {
375                 unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
376                 u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
377
378                 for (j = 0; j < dma_len; j += PAGE_SIZE)
379                         dma_pages[page_cnt++] =
380                                 (dma_addr & PAGE_MASK) + j;
381         }
382
383         ret = ib_map_phys_fmr(ibmr->fmr,
384                                    dma_pages, page_cnt, io_addr);
385         if (ret)
386                 goto out;
387
388         /* Success - we successfully remapped the MR, so we can
389          * safely tear down the old mapping. */
390         rds_ib_teardown_mr(ibmr);
391
392         ibmr->sg = scat;
393         ibmr->sg_len = nents;
394         ibmr->sg_dma_len = sg_dma_len;
395         ibmr->remap_count++;
396
397         rds_ib_stats_inc(s_ib_rdma_mr_used);
398         ret = 0;
399
400 out:
401         kfree(dma_pages);
402
403         return ret;
404 }
405
406 void rds_ib_sync_mr(void *trans_private, int direction)
407 {
408         struct rds_ib_mr *ibmr = trans_private;
409         struct rds_ib_device *rds_ibdev = ibmr->device;
410
411         switch (direction) {
412         case DMA_FROM_DEVICE:
413                 ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
414                         ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
415                 break;
416         case DMA_TO_DEVICE:
417                 ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
418                         ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
419                 break;
420         }
421 }
422
423 static void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
424 {
425         struct rds_ib_device *rds_ibdev = ibmr->device;
426
427         if (ibmr->sg_dma_len) {
428                 ib_dma_unmap_sg(rds_ibdev->dev,
429                                 ibmr->sg, ibmr->sg_len,
430                                 DMA_BIDIRECTIONAL);
431                 ibmr->sg_dma_len = 0;
432         }
433
434         /* Release the s/g list */
435         if (ibmr->sg_len) {
436                 unsigned int i;
437
438                 for (i = 0; i < ibmr->sg_len; ++i) {
439                         struct page *page = sg_page(&ibmr->sg[i]);
440
441                         /* FIXME we need a way to tell a r/w MR
442                          * from a r/o MR */
443                         BUG_ON(irqs_disabled());
444                         set_page_dirty(page);
445                         put_page(page);
446                 }
447                 kfree(ibmr->sg);
448
449                 ibmr->sg = NULL;
450                 ibmr->sg_len = 0;
451         }
452 }
453
454 static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
455 {
456         unsigned int pinned = ibmr->sg_len;
457
458         __rds_ib_teardown_mr(ibmr);
459         if (pinned) {
460                 struct rds_ib_device *rds_ibdev = ibmr->device;
461                 struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
462
463                 atomic_sub(pinned, &pool->free_pinned);
464         }
465 }
466
467 static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
468 {
469         unsigned int item_count;
470
471         item_count = atomic_read(&pool->item_count);
472         if (free_all)
473                 return item_count;
474
475         return 0;
476 }
477
478 /*
479  * Flush our pool of MRs.
480  * At a minimum, all currently unused MRs are unmapped.
481  * If the number of MRs allocated exceeds the limit, we also try
482  * to free as many MRs as needed to get back to this limit.
483  */
484 static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all)
485 {
486         struct rds_ib_mr *ibmr, *next;
487         LIST_HEAD(unmap_list);
488         LIST_HEAD(fmr_list);
489         unsigned long unpinned = 0;
490         unsigned long flags;
491         unsigned int nfreed = 0, ncleaned = 0, free_goal;
492         int ret = 0;
493
494         rds_ib_stats_inc(s_ib_rdma_mr_pool_flush);
495
496         mutex_lock(&pool->flush_lock);
497
498         spin_lock_irqsave(&pool->list_lock, flags);
499         /* Get the list of all MRs to be dropped. Ordering matters -
500          * we want to put drop_list ahead of free_list. */
501         list_splice_init(&pool->free_list, &unmap_list);
502         list_splice_init(&pool->drop_list, &unmap_list);
503         if (free_all)
504                 list_splice_init(&pool->clean_list, &unmap_list);
505         spin_unlock_irqrestore(&pool->list_lock, flags);
506
507         free_goal = rds_ib_flush_goal(pool, free_all);
508
509         if (list_empty(&unmap_list))
510                 goto out;
511
512         /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
513         list_for_each_entry(ibmr, &unmap_list, list)
514                 list_add(&ibmr->fmr->list, &fmr_list);
515         ret = ib_unmap_fmr(&fmr_list);
516         if (ret)
517                 printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret);
518
519         /* Now we can destroy the DMA mapping and unpin any pages */
520         list_for_each_entry_safe(ibmr, next, &unmap_list, list) {
521                 unpinned += ibmr->sg_len;
522                 __rds_ib_teardown_mr(ibmr);
523                 if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) {
524                         rds_ib_stats_inc(s_ib_rdma_mr_free);
525                         list_del(&ibmr->list);
526                         ib_dealloc_fmr(ibmr->fmr);
527                         kfree(ibmr);
528                         nfreed++;
529                 }
530                 ncleaned++;
531         }
532
533         spin_lock_irqsave(&pool->list_lock, flags);
534         list_splice(&unmap_list, &pool->clean_list);
535         spin_unlock_irqrestore(&pool->list_lock, flags);
536
537         atomic_sub(unpinned, &pool->free_pinned);
538         atomic_sub(ncleaned, &pool->dirty_count);
539         atomic_sub(nfreed, &pool->item_count);
540
541 out:
542         mutex_unlock(&pool->flush_lock);
543         return ret;
544 }
545
546 static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
547 {
548         struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker);
549
550         rds_ib_flush_mr_pool(pool, 0);
551 }
552
553 void rds_ib_free_mr(void *trans_private, int invalidate)
554 {
555         struct rds_ib_mr *ibmr = trans_private;
556         struct rds_ib_device *rds_ibdev = ibmr->device;
557         struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
558         unsigned long flags;
559
560         rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
561
562         /* Return it to the pool's free list */
563         spin_lock_irqsave(&pool->list_lock, flags);
564         if (ibmr->remap_count >= pool->fmr_attr.max_maps)
565                 list_add(&ibmr->list, &pool->drop_list);
566         else
567                 list_add(&ibmr->list, &pool->free_list);
568
569         atomic_add(ibmr->sg_len, &pool->free_pinned);
570         atomic_inc(&pool->dirty_count);
571         spin_unlock_irqrestore(&pool->list_lock, flags);
572
573         /* If we've pinned too many pages, request a flush */
574         if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
575             atomic_read(&pool->dirty_count) >= pool->max_items / 10)
576                 queue_work(rds_wq, &pool->flush_worker);
577
578         if (invalidate) {
579                 if (likely(!in_interrupt())) {
580                         rds_ib_flush_mr_pool(pool, 0);
581                 } else {
582                         /* We get here if the user created a MR marked
583                          * as use_once and invalidate at the same time. */
584                         queue_work(rds_wq, &pool->flush_worker);
585                 }
586         }
587 }
588
589 void rds_ib_flush_mrs(void)
590 {
591         struct rds_ib_device *rds_ibdev;
592
593         list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
594                 struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
595
596                 if (pool)
597                         rds_ib_flush_mr_pool(pool, 0);
598         }
599 }
600
601 void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
602                     struct rds_sock *rs, u32 *key_ret)
603 {
604         struct rds_ib_device *rds_ibdev;
605         struct rds_ib_mr *ibmr = NULL;
606         int ret;
607
608         rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
609         if (!rds_ibdev) {
610                 ret = -ENODEV;
611                 goto out;
612         }
613
614         if (!rds_ibdev->mr_pool) {
615                 ret = -ENODEV;
616                 goto out;
617         }
618
619         ibmr = rds_ib_alloc_fmr(rds_ibdev);
620         if (IS_ERR(ibmr))
621                 return ibmr;
622
623         ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
624         if (ret == 0)
625                 *key_ret = ibmr->fmr->rkey;
626         else
627                 printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret);
628
629         ibmr->device = rds_ibdev;
630
631  out:
632         if (ret) {
633                 if (ibmr)
634                         rds_ib_free_mr(ibmr, 0);
635                 ibmr = ERR_PTR(ret);
636         }
637         return ibmr;
638 }