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ib_rdma.c
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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 #include <linux/rculist.h>
36 #include <linux/llist.h>
37 
38 #include "rds.h"
39 #include "ib.h"
40 
41 static DEFINE_PER_CPU(unsigned long, clean_list_grace);
42 #define CLEAN_LIST_BUSY_BIT 0
43 
44 /*
45  * This is stored as mr->r_trans_private.
46  */
47 struct rds_ib_mr {
50  struct ib_fmr *fmr;
51 
53 
54  /* unmap_list is for freeing */
56  unsigned int remap_count;
57 
58  struct scatterlist *sg;
59  unsigned int sg_len;
60  u64 *dma;
62 };
63 
64 /*
65  * Our own little FMR pool
66  */
68  struct mutex flush_lock; /* serialize fmr invalidate */
69  struct delayed_work flush_worker; /* flush worker */
70 
71  atomic_t item_count; /* total # of MRs */
72  atomic_t dirty_count; /* # dirty of MRs */
73 
74  struct llist_head drop_list; /* MRs that have reached their max_maps limit */
75  struct llist_head free_list; /* unused MRs */
76  struct llist_head clean_list; /* global unused & unamapped MRs */
78 
79  atomic_t free_pinned; /* memory pinned by free MRs */
80  unsigned long max_items;
81  unsigned long max_items_soft;
82  unsigned long max_free_pinned;
84 };
85 
86 static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all, struct rds_ib_mr **);
87 static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr);
88 static void rds_ib_mr_pool_flush_worker(struct work_struct *work);
89 
90 static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
91 {
92  struct rds_ib_device *rds_ibdev;
93  struct rds_ib_ipaddr *i_ipaddr;
94 
95  rcu_read_lock();
96  list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) {
97  list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
98  if (i_ipaddr->ipaddr == ipaddr) {
99  atomic_inc(&rds_ibdev->refcount);
100  rcu_read_unlock();
101  return rds_ibdev;
102  }
103  }
104  }
105  rcu_read_unlock();
106 
107  return NULL;
108 }
109 
110 static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
111 {
112  struct rds_ib_ipaddr *i_ipaddr;
113 
114  i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
115  if (!i_ipaddr)
116  return -ENOMEM;
117 
118  i_ipaddr->ipaddr = ipaddr;
119 
120  spin_lock_irq(&rds_ibdev->spinlock);
121  list_add_tail_rcu(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
122  spin_unlock_irq(&rds_ibdev->spinlock);
123 
124  return 0;
125 }
126 
127 static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
128 {
129  struct rds_ib_ipaddr *i_ipaddr;
130  struct rds_ib_ipaddr *to_free = NULL;
131 
132 
133  spin_lock_irq(&rds_ibdev->spinlock);
134  list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
135  if (i_ipaddr->ipaddr == ipaddr) {
136  list_del_rcu(&i_ipaddr->list);
137  to_free = i_ipaddr;
138  break;
139  }
140  }
141  spin_unlock_irq(&rds_ibdev->spinlock);
142 
143  if (to_free) {
144  synchronize_rcu();
145  kfree(to_free);
146  }
147 }
148 
149 int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
150 {
151  struct rds_ib_device *rds_ibdev_old;
152 
153  rds_ibdev_old = rds_ib_get_device(ipaddr);
154  if (rds_ibdev_old) {
155  rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
156  rds_ib_dev_put(rds_ibdev_old);
157  }
158 
159  return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
160 }
161 
162 void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
163 {
164  struct rds_ib_connection *ic = conn->c_transport_data;
165 
166  /* conn was previously on the nodev_conns_list */
167  spin_lock_irq(&ib_nodev_conns_lock);
168  BUG_ON(list_empty(&ib_nodev_conns));
169  BUG_ON(list_empty(&ic->ib_node));
170  list_del(&ic->ib_node);
171 
172  spin_lock(&rds_ibdev->spinlock);
173  list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
174  spin_unlock(&rds_ibdev->spinlock);
175  spin_unlock_irq(&ib_nodev_conns_lock);
176 
177  ic->rds_ibdev = rds_ibdev;
178  atomic_inc(&rds_ibdev->refcount);
179 }
180 
181 void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
182 {
183  struct rds_ib_connection *ic = conn->c_transport_data;
184 
185  /* place conn on nodev_conns_list */
186  spin_lock(&ib_nodev_conns_lock);
187 
188  spin_lock_irq(&rds_ibdev->spinlock);
189  BUG_ON(list_empty(&ic->ib_node));
190  list_del(&ic->ib_node);
191  spin_unlock_irq(&rds_ibdev->spinlock);
192 
194 
195  spin_unlock(&ib_nodev_conns_lock);
196 
197  ic->rds_ibdev = NULL;
198  rds_ib_dev_put(rds_ibdev);
199 }
200 
202 {
203  struct rds_ib_connection *ic, *_ic;
204  LIST_HEAD(tmp_list);
205 
206  /* avoid calling conn_destroy with irqs off */
207  spin_lock_irq(&ib_nodev_conns_lock);
208  list_splice(&ib_nodev_conns, &tmp_list);
209  spin_unlock_irq(&ib_nodev_conns_lock);
210 
211  list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
212  rds_conn_destroy(ic->conn);
213 }
214 
216 {
217  struct rds_ib_mr_pool *pool;
218 
219  pool = kzalloc(sizeof(*pool), GFP_KERNEL);
220  if (!pool)
221  return ERR_PTR(-ENOMEM);
222 
223  init_llist_head(&pool->free_list);
224  init_llist_head(&pool->drop_list);
225  init_llist_head(&pool->clean_list);
226  mutex_init(&pool->flush_lock);
228  INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
229 
230  pool->fmr_attr.max_pages = fmr_message_size;
231  pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
232  pool->fmr_attr.page_shift = PAGE_SHIFT;
233  pool->max_free_pinned = rds_ibdev->max_fmrs * fmr_message_size / 4;
234 
235  /* We never allow more than max_items MRs to be allocated.
236  * When we exceed more than max_items_soft, we start freeing
237  * items more aggressively.
238  * Make sure that max_items > max_items_soft > max_items / 2
239  */
240  pool->max_items_soft = rds_ibdev->max_fmrs * 3 / 4;
241  pool->max_items = rds_ibdev->max_fmrs;
242 
243  return pool;
244 }
245 
246 void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
247 {
248  struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
249 
250  iinfo->rdma_mr_max = pool->max_items;
251  iinfo->rdma_mr_size = pool->fmr_attr.max_pages;
252 }
253 
255 {
257  rds_ib_flush_mr_pool(pool, 1, NULL);
258  WARN_ON(atomic_read(&pool->item_count));
260  kfree(pool);
261 }
262 
263 static inline struct rds_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool)
264 {
265  struct rds_ib_mr *ibmr = NULL;
266  struct llist_node *ret;
267  unsigned long *flag;
268 
269  preempt_disable();
270  flag = &__get_cpu_var(clean_list_grace);
272  ret = llist_del_first(&pool->clean_list);
273  if (ret)
274  ibmr = llist_entry(ret, struct rds_ib_mr, llnode);
275 
277  preempt_enable();
278  return ibmr;
279 }
280 
281 static inline void wait_clean_list_grace(void)
282 {
283  int cpu;
284  unsigned long *flag;
285 
286  for_each_online_cpu(cpu) {
287  flag = &per_cpu(clean_list_grace, cpu);
288  while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
289  cpu_relax();
290  }
291 }
292 
293 static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev)
294 {
295  struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
296  struct rds_ib_mr *ibmr = NULL;
297  int err = 0, iter = 0;
298 
299  if (atomic_read(&pool->dirty_count) >= pool->max_items / 10)
301 
302  while (1) {
303  ibmr = rds_ib_reuse_fmr(pool);
304  if (ibmr)
305  return ibmr;
306 
307  /* No clean MRs - now we have the choice of either
308  * allocating a fresh MR up to the limit imposed by the
309  * driver, or flush any dirty unused MRs.
310  * We try to avoid stalling in the send path if possible,
311  * so we allocate as long as we're allowed to.
312  *
313  * We're fussy with enforcing the FMR limit, though. If the driver
314  * tells us we can't use more than N fmrs, we shouldn't start
315  * arguing with it */
316  if (atomic_inc_return(&pool->item_count) <= pool->max_items)
317  break;
318 
319  atomic_dec(&pool->item_count);
320 
321  if (++iter > 2) {
322  rds_ib_stats_inc(s_ib_rdma_mr_pool_depleted);
323  return ERR_PTR(-EAGAIN);
324  }
325 
326  /* We do have some empty MRs. Flush them out. */
327  rds_ib_stats_inc(s_ib_rdma_mr_pool_wait);
328  rds_ib_flush_mr_pool(pool, 0, &ibmr);
329  if (ibmr)
330  return ibmr;
331  }
332 
333  ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL, rdsibdev_to_node(rds_ibdev));
334  if (!ibmr) {
335  err = -ENOMEM;
336  goto out_no_cigar;
337  }
338 
339  memset(ibmr, 0, sizeof(*ibmr));
340 
341  ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
346  &pool->fmr_attr);
347  if (IS_ERR(ibmr->fmr)) {
348  err = PTR_ERR(ibmr->fmr);
349  ibmr->fmr = NULL;
350  printk(KERN_WARNING "RDS/IB: ib_alloc_fmr failed (err=%d)\n", err);
351  goto out_no_cigar;
352  }
353 
354  rds_ib_stats_inc(s_ib_rdma_mr_alloc);
355  return ibmr;
356 
357 out_no_cigar:
358  if (ibmr) {
359  if (ibmr->fmr)
360  ib_dealloc_fmr(ibmr->fmr);
361  kfree(ibmr);
362  }
363  atomic_dec(&pool->item_count);
364  return ERR_PTR(err);
365 }
366 
367 static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
368  struct scatterlist *sg, unsigned int nents)
369 {
370  struct ib_device *dev = rds_ibdev->dev;
371  struct scatterlist *scat = sg;
372  u64 io_addr = 0;
373  u64 *dma_pages;
374  u32 len;
375  int page_cnt, sg_dma_len;
376  int i, j;
377  int ret;
378 
379  sg_dma_len = ib_dma_map_sg(dev, sg, nents,
381  if (unlikely(!sg_dma_len)) {
382  printk(KERN_WARNING "RDS/IB: dma_map_sg failed!\n");
383  return -EBUSY;
384  }
385 
386  len = 0;
387  page_cnt = 0;
388 
389  for (i = 0; i < sg_dma_len; ++i) {
390  unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
391  u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
392 
393  if (dma_addr & ~PAGE_MASK) {
394  if (i > 0)
395  return -EINVAL;
396  else
397  ++page_cnt;
398  }
399  if ((dma_addr + dma_len) & ~PAGE_MASK) {
400  if (i < sg_dma_len - 1)
401  return -EINVAL;
402  else
403  ++page_cnt;
404  }
405 
406  len += dma_len;
407  }
408 
409  page_cnt += len >> PAGE_SHIFT;
410  if (page_cnt > fmr_message_size)
411  return -EINVAL;
412 
413  dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC,
414  rdsibdev_to_node(rds_ibdev));
415  if (!dma_pages)
416  return -ENOMEM;
417 
418  page_cnt = 0;
419  for (i = 0; i < sg_dma_len; ++i) {
420  unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
421  u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
422 
423  for (j = 0; j < dma_len; j += PAGE_SIZE)
424  dma_pages[page_cnt++] =
425  (dma_addr & PAGE_MASK) + j;
426  }
427 
428  ret = ib_map_phys_fmr(ibmr->fmr,
429  dma_pages, page_cnt, io_addr);
430  if (ret)
431  goto out;
432 
433  /* Success - we successfully remapped the MR, so we can
434  * safely tear down the old mapping. */
435  rds_ib_teardown_mr(ibmr);
436 
437  ibmr->sg = scat;
438  ibmr->sg_len = nents;
439  ibmr->sg_dma_len = sg_dma_len;
440  ibmr->remap_count++;
441 
442  rds_ib_stats_inc(s_ib_rdma_mr_used);
443  ret = 0;
444 
445 out:
446  kfree(dma_pages);
447 
448  return ret;
449 }
450 
451 void rds_ib_sync_mr(void *trans_private, int direction)
452 {
453  struct rds_ib_mr *ibmr = trans_private;
454  struct rds_ib_device *rds_ibdev = ibmr->device;
455 
456  switch (direction) {
457  case DMA_FROM_DEVICE:
458  ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
460  break;
461  case DMA_TO_DEVICE:
462  ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
464  break;
465  }
466 }
467 
468 static void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
469 {
470  struct rds_ib_device *rds_ibdev = ibmr->device;
471 
472  if (ibmr->sg_dma_len) {
473  ib_dma_unmap_sg(rds_ibdev->dev,
474  ibmr->sg, ibmr->sg_len,
476  ibmr->sg_dma_len = 0;
477  }
478 
479  /* Release the s/g list */
480  if (ibmr->sg_len) {
481  unsigned int i;
482 
483  for (i = 0; i < ibmr->sg_len; ++i) {
484  struct page *page = sg_page(&ibmr->sg[i]);
485 
486  /* FIXME we need a way to tell a r/w MR
487  * from a r/o MR */
489  set_page_dirty(page);
490  put_page(page);
491  }
492  kfree(ibmr->sg);
493 
494  ibmr->sg = NULL;
495  ibmr->sg_len = 0;
496  }
497 }
498 
499 static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
500 {
501  unsigned int pinned = ibmr->sg_len;
502 
503  __rds_ib_teardown_mr(ibmr);
504  if (pinned) {
505  struct rds_ib_device *rds_ibdev = ibmr->device;
506  struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
507 
508  atomic_sub(pinned, &pool->free_pinned);
509  }
510 }
511 
512 static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
513 {
514  unsigned int item_count;
515 
516  item_count = atomic_read(&pool->item_count);
517  if (free_all)
518  return item_count;
519 
520  return 0;
521 }
522 
523 /*
524  * given an llist of mrs, put them all into the list_head for more processing
525  */
526 static void llist_append_to_list(struct llist_head *llist, struct list_head *list)
527 {
528  struct rds_ib_mr *ibmr;
529  struct llist_node *node;
530  struct llist_node *next;
531 
532  node = llist_del_all(llist);
533  while (node) {
534  next = node->next;
535  ibmr = llist_entry(node, struct rds_ib_mr, llnode);
536  list_add_tail(&ibmr->unmap_list, list);
537  node = next;
538  }
539 }
540 
541 /*
542  * this takes a list head of mrs and turns it into linked llist nodes
543  * of clusters. Each cluster has linked llist nodes of
544  * MR_CLUSTER_SIZE mrs that are ready for reuse.
545  */
546 static void list_to_llist_nodes(struct rds_ib_mr_pool *pool,
547  struct list_head *list,
548  struct llist_node **nodes_head,
549  struct llist_node **nodes_tail)
550 {
551  struct rds_ib_mr *ibmr;
552  struct llist_node *cur = NULL;
553  struct llist_node **next = nodes_head;
554 
555  list_for_each_entry(ibmr, list, unmap_list) {
556  cur = &ibmr->llnode;
557  *next = cur;
558  next = &cur->next;
559  }
560  *next = NULL;
561  *nodes_tail = cur;
562 }
563 
564 /*
565  * Flush our pool of MRs.
566  * At a minimum, all currently unused MRs are unmapped.
567  * If the number of MRs allocated exceeds the limit, we also try
568  * to free as many MRs as needed to get back to this limit.
569  */
570 static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
571  int free_all, struct rds_ib_mr **ibmr_ret)
572 {
573  struct rds_ib_mr *ibmr, *next;
574  struct llist_node *clean_nodes;
575  struct llist_node *clean_tail;
576  LIST_HEAD(unmap_list);
577  LIST_HEAD(fmr_list);
578  unsigned long unpinned = 0;
579  unsigned int nfreed = 0, ncleaned = 0, free_goal;
580  int ret = 0;
581 
582  rds_ib_stats_inc(s_ib_rdma_mr_pool_flush);
583 
584  if (ibmr_ret) {
585  DEFINE_WAIT(wait);
586  while(!mutex_trylock(&pool->flush_lock)) {
587  ibmr = rds_ib_reuse_fmr(pool);
588  if (ibmr) {
589  *ibmr_ret = ibmr;
590  finish_wait(&pool->flush_wait, &wait);
591  goto out_nolock;
592  }
593 
596  if (llist_empty(&pool->clean_list))
597  schedule();
598 
599  ibmr = rds_ib_reuse_fmr(pool);
600  if (ibmr) {
601  *ibmr_ret = ibmr;
602  finish_wait(&pool->flush_wait, &wait);
603  goto out_nolock;
604  }
605  }
606  finish_wait(&pool->flush_wait, &wait);
607  } else
608  mutex_lock(&pool->flush_lock);
609 
610  if (ibmr_ret) {
611  ibmr = rds_ib_reuse_fmr(pool);
612  if (ibmr) {
613  *ibmr_ret = ibmr;
614  goto out;
615  }
616  }
617 
618  /* Get the list of all MRs to be dropped. Ordering matters -
619  * we want to put drop_list ahead of free_list.
620  */
621  llist_append_to_list(&pool->drop_list, &unmap_list);
622  llist_append_to_list(&pool->free_list, &unmap_list);
623  if (free_all)
624  llist_append_to_list(&pool->clean_list, &unmap_list);
625 
626  free_goal = rds_ib_flush_goal(pool, free_all);
627 
628  if (list_empty(&unmap_list))
629  goto out;
630 
631  /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
632  list_for_each_entry(ibmr, &unmap_list, unmap_list)
633  list_add(&ibmr->fmr->list, &fmr_list);
634 
635  ret = ib_unmap_fmr(&fmr_list);
636  if (ret)
637  printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret);
638 
639  /* Now we can destroy the DMA mapping and unpin any pages */
640  list_for_each_entry_safe(ibmr, next, &unmap_list, unmap_list) {
641  unpinned += ibmr->sg_len;
642  __rds_ib_teardown_mr(ibmr);
643  if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) {
644  rds_ib_stats_inc(s_ib_rdma_mr_free);
645  list_del(&ibmr->unmap_list);
646  ib_dealloc_fmr(ibmr->fmr);
647  kfree(ibmr);
648  nfreed++;
649  }
650  ncleaned++;
651  }
652 
653  if (!list_empty(&unmap_list)) {
654  /* we have to make sure that none of the things we're about
655  * to put on the clean list would race with other cpus trying
656  * to pull items off. The llist would explode if we managed to
657  * remove something from the clean list and then add it back again
658  * while another CPU was spinning on that same item in llist_del_first.
659  *
660  * This is pretty unlikely, but just in case wait for an llist grace period
661  * here before adding anything back into the clean list.
662  */
663  wait_clean_list_grace();
664 
665  list_to_llist_nodes(pool, &unmap_list, &clean_nodes, &clean_tail);
666  if (ibmr_ret)
667  *ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode);
668 
669  /* more than one entry in llist nodes */
670  if (clean_nodes->next)
671  llist_add_batch(clean_nodes->next, clean_tail, &pool->clean_list);
672 
673  }
674 
675  atomic_sub(unpinned, &pool->free_pinned);
676  atomic_sub(ncleaned, &pool->dirty_count);
677  atomic_sub(nfreed, &pool->item_count);
678 
679 out:
680  mutex_unlock(&pool->flush_lock);
681  if (waitqueue_active(&pool->flush_wait))
682  wake_up(&pool->flush_wait);
683 out_nolock:
684  return ret;
685 }
686 
687 static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
688 {
689  struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work);
690 
691  rds_ib_flush_mr_pool(pool, 0, NULL);
692 }
693 
694 void rds_ib_free_mr(void *trans_private, int invalidate)
695 {
696  struct rds_ib_mr *ibmr = trans_private;
697  struct rds_ib_device *rds_ibdev = ibmr->device;
698  struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
699 
700  rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
701 
702  /* Return it to the pool's free list */
703  if (ibmr->remap_count >= pool->fmr_attr.max_maps)
704  llist_add(&ibmr->llnode, &pool->drop_list);
705  else
706  llist_add(&ibmr->llnode, &pool->free_list);
707 
708  atomic_add(ibmr->sg_len, &pool->free_pinned);
709  atomic_inc(&pool->dirty_count);
710 
711  /* If we've pinned too many pages, request a flush */
712  if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
713  atomic_read(&pool->dirty_count) >= pool->max_items / 10)
715 
716  if (invalidate) {
717  if (likely(!in_interrupt())) {
718  rds_ib_flush_mr_pool(pool, 0, NULL);
719  } else {
720  /* We get here if the user created a MR marked
721  * as use_once and invalidate at the same time. */
723  }
724  }
725 
726  rds_ib_dev_put(rds_ibdev);
727 }
728 
730 {
731  struct rds_ib_device *rds_ibdev;
732 
734  list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
735  struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
736 
737  if (pool)
738  rds_ib_flush_mr_pool(pool, 0, NULL);
739  }
741 }
742 
743 void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
744  struct rds_sock *rs, u32 *key_ret)
745 {
746  struct rds_ib_device *rds_ibdev;
747  struct rds_ib_mr *ibmr = NULL;
748  int ret;
749 
750  rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
751  if (!rds_ibdev) {
752  ret = -ENODEV;
753  goto out;
754  }
755 
756  if (!rds_ibdev->mr_pool) {
757  ret = -ENODEV;
758  goto out;
759  }
760 
761  ibmr = rds_ib_alloc_fmr(rds_ibdev);
762  if (IS_ERR(ibmr))
763  return ibmr;
764 
765  ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
766  if (ret == 0)
767  *key_ret = ibmr->fmr->rkey;
768  else
769  printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret);
770 
771  ibmr->device = rds_ibdev;
772  rds_ibdev = NULL;
773 
774  out:
775  if (ret) {
776  if (ibmr)
777  rds_ib_free_mr(ibmr, 0);
778  ibmr = ERR_PTR(ret);
779  }
780  if (rds_ibdev)
781  rds_ib_dev_put(rds_ibdev);
782  return ibmr;
783 }
784