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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 "ib_mr.h"
39
40struct workqueue_struct *rds_ib_mr_wq;
41
42static DEFINE_PER_CPU(unsigned long, clean_list_grace);
43#define CLEAN_LIST_BUSY_BIT 0
44
45static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
46{
47 struct rds_ib_device *rds_ibdev;
48 struct rds_ib_ipaddr *i_ipaddr;
49
50 rcu_read_lock();
51 list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) {
52 list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
53 if (i_ipaddr->ipaddr == ipaddr) {
54 atomic_inc(&rds_ibdev->refcount);
55 rcu_read_unlock();
56 return rds_ibdev;
57 }
58 }
59 }
60 rcu_read_unlock();
61
62 return NULL;
63}
64
65static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
66{
67 struct rds_ib_ipaddr *i_ipaddr;
68
69 i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
70 if (!i_ipaddr)
71 return -ENOMEM;
72
73 i_ipaddr->ipaddr = ipaddr;
74
75 spin_lock_irq(&rds_ibdev->spinlock);
76 list_add_tail_rcu(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
77 spin_unlock_irq(&rds_ibdev->spinlock);
78
79 return 0;
80}
81
82static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
83{
84 struct rds_ib_ipaddr *i_ipaddr;
85 struct rds_ib_ipaddr *to_free = NULL;
86
87
88 spin_lock_irq(&rds_ibdev->spinlock);
89 list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
90 if (i_ipaddr->ipaddr == ipaddr) {
91 list_del_rcu(&i_ipaddr->list);
92 to_free = i_ipaddr;
93 break;
94 }
95 }
96 spin_unlock_irq(&rds_ibdev->spinlock);
97
98 if (to_free)
99 kfree_rcu(to_free, rcu);
100}
101
102int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
103{
104 struct rds_ib_device *rds_ibdev_old;
105
106 rds_ibdev_old = rds_ib_get_device(ipaddr);
107 if (!rds_ibdev_old)
108 return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
109
110 if (rds_ibdev_old != rds_ibdev) {
111 rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
112 rds_ib_dev_put(rds_ibdev_old);
113 return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
114 }
115 rds_ib_dev_put(rds_ibdev_old);
116
117 return 0;
118}
119
120void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
121{
122 struct rds_ib_connection *ic = conn->c_transport_data;
123
124 /* conn was previously on the nodev_conns_list */
125 spin_lock_irq(&ib_nodev_conns_lock);
126 BUG_ON(list_empty(&ib_nodev_conns));
127 BUG_ON(list_empty(&ic->ib_node));
128 list_del(&ic->ib_node);
129
130 spin_lock(&rds_ibdev->spinlock);
131 list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
132 spin_unlock(&rds_ibdev->spinlock);
133 spin_unlock_irq(&ib_nodev_conns_lock);
134
135 ic->rds_ibdev = rds_ibdev;
136 atomic_inc(&rds_ibdev->refcount);
137}
138
139void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
140{
141 struct rds_ib_connection *ic = conn->c_transport_data;
142
143 /* place conn on nodev_conns_list */
144 spin_lock(&ib_nodev_conns_lock);
145
146 spin_lock_irq(&rds_ibdev->spinlock);
147 BUG_ON(list_empty(&ic->ib_node));
148 list_del(&ic->ib_node);
149 spin_unlock_irq(&rds_ibdev->spinlock);
150
151 list_add_tail(&ic->ib_node, &ib_nodev_conns);
152
153 spin_unlock(&ib_nodev_conns_lock);
154
155 ic->rds_ibdev = NULL;
156 rds_ib_dev_put(rds_ibdev);
157}
158
159void rds_ib_destroy_nodev_conns(void)
160{
161 struct rds_ib_connection *ic, *_ic;
162 LIST_HEAD(tmp_list);
163
164 /* avoid calling conn_destroy with irqs off */
165 spin_lock_irq(&ib_nodev_conns_lock);
166 list_splice(&ib_nodev_conns, &tmp_list);
167 spin_unlock_irq(&ib_nodev_conns_lock);
168
169 list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
170 rds_conn_destroy(ic->conn);
171}
172
173void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
174{
175 struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
176
177 iinfo->rdma_mr_max = pool_1m->max_items;
178 iinfo->rdma_mr_size = pool_1m->fmr_attr.max_pages;
179}
180
181struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *pool)
182{
183 struct rds_ib_mr *ibmr = NULL;
184 struct llist_node *ret;
185 unsigned long *flag;
186
187 preempt_disable();
188 flag = this_cpu_ptr(&clean_list_grace);
189 set_bit(CLEAN_LIST_BUSY_BIT, flag);
190 ret = llist_del_first(&pool->clean_list);
191 if (ret) {
192 ibmr = llist_entry(ret, struct rds_ib_mr, llnode);
193 if (pool->pool_type == RDS_IB_MR_8K_POOL)
194 rds_ib_stats_inc(s_ib_rdma_mr_8k_reused);
195 else
196 rds_ib_stats_inc(s_ib_rdma_mr_1m_reused);
197 }
198
199 clear_bit(CLEAN_LIST_BUSY_BIT, flag);
200 preempt_enable();
201 return ibmr;
202}
203
204static inline void wait_clean_list_grace(void)
205{
206 int cpu;
207 unsigned long *flag;
208
209 for_each_online_cpu(cpu) {
210 flag = &per_cpu(clean_list_grace, cpu);
211 while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
212 cpu_relax();
213 }
214}
215
216void rds_ib_sync_mr(void *trans_private, int direction)
217{
218 struct rds_ib_mr *ibmr = trans_private;
219 struct rds_ib_device *rds_ibdev = ibmr->device;
220
221 switch (direction) {
222 case DMA_FROM_DEVICE:
223 ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
224 ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
225 break;
226 case DMA_TO_DEVICE:
227 ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
228 ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
229 break;
230 }
231}
232
233void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
234{
235 struct rds_ib_device *rds_ibdev = ibmr->device;
236
237 if (ibmr->sg_dma_len) {
238 ib_dma_unmap_sg(rds_ibdev->dev,
239 ibmr->sg, ibmr->sg_len,
240 DMA_BIDIRECTIONAL);
241 ibmr->sg_dma_len = 0;
242 }
243
244 /* Release the s/g list */
245 if (ibmr->sg_len) {
246 unsigned int i;
247
248 for (i = 0; i < ibmr->sg_len; ++i) {
249 struct page *page = sg_page(&ibmr->sg[i]);
250
251 /* FIXME we need a way to tell a r/w MR
252 * from a r/o MR */
253 WARN_ON(!page->mapping && irqs_disabled());
254 set_page_dirty(page);
255 put_page(page);
256 }
257 kfree(ibmr->sg);
258
259 ibmr->sg = NULL;
260 ibmr->sg_len = 0;
261 }
262}
263
264void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
265{
266 unsigned int pinned = ibmr->sg_len;
267
268 __rds_ib_teardown_mr(ibmr);
269 if (pinned) {
270 struct rds_ib_mr_pool *pool = ibmr->pool;
271
272 atomic_sub(pinned, &pool->free_pinned);
273 }
274}
275
276static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
277{
278 unsigned int item_count;
279
280 item_count = atomic_read(&pool->item_count);
281 if (free_all)
282 return item_count;
283
284 return 0;
285}
286
287/*
288 * given an llist of mrs, put them all into the list_head for more processing
289 */
290static unsigned int llist_append_to_list(struct llist_head *llist,
291 struct list_head *list)
292{
293 struct rds_ib_mr *ibmr;
294 struct llist_node *node;
295 struct llist_node *next;
296 unsigned int count = 0;
297
298 node = llist_del_all(llist);
299 while (node) {
300 next = node->next;
301 ibmr = llist_entry(node, struct rds_ib_mr, llnode);
302 list_add_tail(&ibmr->unmap_list, list);
303 node = next;
304 count++;
305 }
306 return count;
307}
308
309/*
310 * this takes a list head of mrs and turns it into linked llist nodes
311 * of clusters. Each cluster has linked llist nodes of
312 * MR_CLUSTER_SIZE mrs that are ready for reuse.
313 */
314static void list_to_llist_nodes(struct rds_ib_mr_pool *pool,
315 struct list_head *list,
316 struct llist_node **nodes_head,
317 struct llist_node **nodes_tail)
318{
319 struct rds_ib_mr *ibmr;
320 struct llist_node *cur = NULL;
321 struct llist_node **next = nodes_head;
322
323 list_for_each_entry(ibmr, list, unmap_list) {
324 cur = &ibmr->llnode;
325 *next = cur;
326 next = &cur->next;
327 }
328 *next = NULL;
329 *nodes_tail = cur;
330}
331
332/*
333 * Flush our pool of MRs.
334 * At a minimum, all currently unused MRs are unmapped.
335 * If the number of MRs allocated exceeds the limit, we also try
336 * to free as many MRs as needed to get back to this limit.
337 */
338int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
339 int free_all, struct rds_ib_mr **ibmr_ret)
340{
341 struct rds_ib_mr *ibmr;
342 struct llist_node *clean_nodes;
343 struct llist_node *clean_tail;
344 LIST_HEAD(unmap_list);
345 unsigned long unpinned = 0;
346 unsigned int nfreed = 0, dirty_to_clean = 0, free_goal;
347
348 if (pool->pool_type == RDS_IB_MR_8K_POOL)
349 rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_flush);
350 else
351 rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_flush);
352
353 if (ibmr_ret) {
354 DEFINE_WAIT(wait);
355 while (!mutex_trylock(&pool->flush_lock)) {
356 ibmr = rds_ib_reuse_mr(pool);
357 if (ibmr) {
358 *ibmr_ret = ibmr;
359 finish_wait(&pool->flush_wait, &wait);
360 goto out_nolock;
361 }
362
363 prepare_to_wait(&pool->flush_wait, &wait,
364 TASK_UNINTERRUPTIBLE);
365 if (llist_empty(&pool->clean_list))
366 schedule();
367
368 ibmr = rds_ib_reuse_mr(pool);
369 if (ibmr) {
370 *ibmr_ret = ibmr;
371 finish_wait(&pool->flush_wait, &wait);
372 goto out_nolock;
373 }
374 }
375 finish_wait(&pool->flush_wait, &wait);
376 } else
377 mutex_lock(&pool->flush_lock);
378
379 if (ibmr_ret) {
380 ibmr = rds_ib_reuse_mr(pool);
381 if (ibmr) {
382 *ibmr_ret = ibmr;
383 goto out;
384 }
385 }
386
387 /* Get the list of all MRs to be dropped. Ordering matters -
388 * we want to put drop_list ahead of free_list.
389 */
390 dirty_to_clean = llist_append_to_list(&pool->drop_list, &unmap_list);
391 dirty_to_clean += llist_append_to_list(&pool->free_list, &unmap_list);
392 if (free_all)
393 llist_append_to_list(&pool->clean_list, &unmap_list);
394
395 free_goal = rds_ib_flush_goal(pool, free_all);
396
397 if (list_empty(&unmap_list))
398 goto out;
399
400 if (pool->use_fastreg)
401 rds_ib_unreg_frmr(&unmap_list, &nfreed, &unpinned, free_goal);
402 else
403 rds_ib_unreg_fmr(&unmap_list, &nfreed, &unpinned, free_goal);
404
405 if (!list_empty(&unmap_list)) {
406 /* we have to make sure that none of the things we're about
407 * to put on the clean list would race with other cpus trying
408 * to pull items off. The llist would explode if we managed to
409 * remove something from the clean list and then add it back again
410 * while another CPU was spinning on that same item in llist_del_first.
411 *
412 * This is pretty unlikely, but just in case wait for an llist grace period
413 * here before adding anything back into the clean list.
414 */
415 wait_clean_list_grace();
416
417 list_to_llist_nodes(pool, &unmap_list, &clean_nodes, &clean_tail);
418 if (ibmr_ret)
419 *ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode);
420
421 /* more than one entry in llist nodes */
422 if (clean_nodes->next)
423 llist_add_batch(clean_nodes->next, clean_tail, &pool->clean_list);
424
425 }
426
427 atomic_sub(unpinned, &pool->free_pinned);
428 atomic_sub(dirty_to_clean, &pool->dirty_count);
429 atomic_sub(nfreed, &pool->item_count);
430
431out:
432 mutex_unlock(&pool->flush_lock);
433 if (waitqueue_active(&pool->flush_wait))
434 wake_up(&pool->flush_wait);
435out_nolock:
436 return 0;
437}
438
439struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *pool)
440{
441 struct rds_ib_mr *ibmr = NULL;
442 int iter = 0;
443
444 if (atomic_read(&pool->dirty_count) >= pool->max_items_soft / 10)
445 queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
446
447 while (1) {
448 ibmr = rds_ib_reuse_mr(pool);
449 if (ibmr)
450 return ibmr;
451
452 if (atomic_inc_return(&pool->item_count) <= pool->max_items)
453 break;
454
455 atomic_dec(&pool->item_count);
456
457 if (++iter > 2) {
458 if (pool->pool_type == RDS_IB_MR_8K_POOL)
459 rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_depleted);
460 else
461 rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_depleted);
462 return ERR_PTR(-EAGAIN);
463 }
464
465 /* We do have some empty MRs. Flush them out. */
466 if (pool->pool_type == RDS_IB_MR_8K_POOL)
467 rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_wait);
468 else
469 rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_wait);
470
471 rds_ib_flush_mr_pool(pool, 0, &ibmr);
472 if (ibmr)
473 return ibmr;
474 }
475
476 return ibmr;
477}
478
479static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
480{
481 struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work);
482
483 rds_ib_flush_mr_pool(pool, 0, NULL);
484}
485
486void rds_ib_free_mr(void *trans_private, int invalidate)
487{
488 struct rds_ib_mr *ibmr = trans_private;
489 struct rds_ib_mr_pool *pool = ibmr->pool;
490 struct rds_ib_device *rds_ibdev = ibmr->device;
491
492 rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
493
494 /* Return it to the pool's free list */
495 if (rds_ibdev->use_fastreg)
496 rds_ib_free_frmr_list(ibmr);
497 else
498 rds_ib_free_fmr_list(ibmr);
499
500 atomic_add(ibmr->sg_len, &pool->free_pinned);
501 atomic_inc(&pool->dirty_count);
502
503 /* If we've pinned too many pages, request a flush */
504 if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
505 atomic_read(&pool->dirty_count) >= pool->max_items / 5)
506 queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
507
508 if (invalidate) {
509 if (likely(!in_interrupt())) {
510 rds_ib_flush_mr_pool(pool, 0, NULL);
511 } else {
512 /* We get here if the user created a MR marked
513 * as use_once and invalidate at the same time.
514 */
515 queue_delayed_work(rds_ib_mr_wq,
516 &pool->flush_worker, 10);
517 }
518 }
519
520 rds_ib_dev_put(rds_ibdev);
521}
522
523void rds_ib_flush_mrs(void)
524{
525 struct rds_ib_device *rds_ibdev;
526
527 down_read(&rds_ib_devices_lock);
528 list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
529 if (rds_ibdev->mr_8k_pool)
530 rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 0, NULL);
531
532 if (rds_ibdev->mr_1m_pool)
533 rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 0, NULL);
534 }
535 up_read(&rds_ib_devices_lock);
536}
537
538void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
539 struct rds_sock *rs, u32 *key_ret)
540{
541 struct rds_ib_device *rds_ibdev;
542 struct rds_ib_mr *ibmr = NULL;
543 struct rds_ib_connection *ic = rs->rs_conn->c_transport_data;
544 int ret;
545
546 rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
547 if (!rds_ibdev) {
548 ret = -ENODEV;
549 goto out;
550 }
551
552 if (!rds_ibdev->mr_8k_pool || !rds_ibdev->mr_1m_pool) {
553 ret = -ENODEV;
554 goto out;
555 }
556
557 if (rds_ibdev->use_fastreg)
558 ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
559 else
560 ibmr = rds_ib_reg_fmr(rds_ibdev, sg, nents, key_ret);
561 if (ibmr)
562 rds_ibdev = NULL;
563
564 out:
565 if (!ibmr)
566 pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret);
567
568 if (rds_ibdev)
569 rds_ib_dev_put(rds_ibdev);
570
571 return ibmr;
572}
573
574void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
575{
576 cancel_delayed_work_sync(&pool->flush_worker);
577 rds_ib_flush_mr_pool(pool, 1, NULL);
578 WARN_ON(atomic_read(&pool->item_count));
579 WARN_ON(atomic_read(&pool->free_pinned));
580 kfree(pool);
581}
582
583struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev,
584 int pool_type)
585{
586 struct rds_ib_mr_pool *pool;
587
588 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
589 if (!pool)
590 return ERR_PTR(-ENOMEM);
591
592 pool->pool_type = pool_type;
593 init_llist_head(&pool->free_list);
594 init_llist_head(&pool->drop_list);
595 init_llist_head(&pool->clean_list);
596 mutex_init(&pool->flush_lock);
597 init_waitqueue_head(&pool->flush_wait);
598 INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
599
600 if (pool_type == RDS_IB_MR_1M_POOL) {
601 /* +1 allows for unaligned MRs */
602 pool->fmr_attr.max_pages = RDS_MR_1M_MSG_SIZE + 1;
603 pool->max_items = RDS_MR_1M_POOL_SIZE;
604 } else {
605 /* pool_type == RDS_IB_MR_8K_POOL */
606 pool->fmr_attr.max_pages = RDS_MR_8K_MSG_SIZE + 1;
607 pool->max_items = RDS_MR_8K_POOL_SIZE;
608 }
609
610 pool->max_free_pinned = pool->max_items * pool->fmr_attr.max_pages / 4;
611 pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
612 pool->fmr_attr.page_shift = PAGE_SHIFT;
613 pool->max_items_soft = rds_ibdev->max_mrs * 3 / 4;
614 pool->use_fastreg = rds_ibdev->use_fastreg;
615
616 return pool;
617}
618
619int rds_ib_mr_init(void)
620{
621 rds_ib_mr_wq = create_workqueue("rds_mr_flushd");
622 if (!rds_ib_mr_wq)
623 return -ENOMEM;
624 return 0;
625}
626
627/* By the time this is called all the IB devices should have been torn down and
628 * had their pools freed. As each pool is freed its work struct is waited on,
629 * so the pool flushing work queue should be idle by the time we get here.
630 */
631void rds_ib_mr_exit(void)
632{
633 destroy_workqueue(rds_ib_mr_wq);
634}
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
37#include "rds.h"
38#include "ib.h"
39#include "xlist.h"
40
41static 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 */
47struct rds_ib_mr {
48 struct rds_ib_device *device;
49 struct rds_ib_mr_pool *pool;
50 struct ib_fmr *fmr;
51
52 struct xlist_head xlist;
53
54 /* unmap_list is for freeing */
55 struct list_head unmap_list;
56 unsigned int remap_count;
57
58 struct scatterlist *sg;
59 unsigned int sg_len;
60 u64 *dma;
61 int sg_dma_len;
62};
63
64/*
65 * Our own little FMR pool
66 */
67struct rds_ib_mr_pool {
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 xlist_head drop_list; /* MRs that have reached their max_maps limit */
75 struct xlist_head free_list; /* unused MRs */
76 struct xlist_head clean_list; /* global unused & unamapped MRs */
77 wait_queue_head_t flush_wait;
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;
83 struct ib_fmr_attr fmr_attr;
84};
85
86static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all, struct rds_ib_mr **);
87static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr);
88static void rds_ib_mr_pool_flush_worker(struct work_struct *work);
89
90static 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
110static 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
127static 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
149int 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
162void 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
181void 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
193 list_add_tail(&ic->ib_node, &ib_nodev_conns);
194
195 spin_unlock(&ib_nodev_conns_lock);
196
197 ic->rds_ibdev = NULL;
198 rds_ib_dev_put(rds_ibdev);
199}
200
201void rds_ib_destroy_nodev_conns(void)
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
215struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev)
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_XLIST_HEAD(&pool->free_list);
224 INIT_XLIST_HEAD(&pool->drop_list);
225 INIT_XLIST_HEAD(&pool->clean_list);
226 mutex_init(&pool->flush_lock);
227 init_waitqueue_head(&pool->flush_wait);
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
246void 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
254void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
255{
256 cancel_delayed_work_sync(&pool->flush_worker);
257 rds_ib_flush_mr_pool(pool, 1, NULL);
258 WARN_ON(atomic_read(&pool->item_count));
259 WARN_ON(atomic_read(&pool->free_pinned));
260 kfree(pool);
261}
262
263static void refill_local(struct rds_ib_mr_pool *pool, struct xlist_head *xl,
264 struct rds_ib_mr **ibmr_ret)
265{
266 struct xlist_head *ibmr_xl;
267 ibmr_xl = xlist_del_head_fast(xl);
268 *ibmr_ret = list_entry(ibmr_xl, struct rds_ib_mr, xlist);
269}
270
271static inline struct rds_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool)
272{
273 struct rds_ib_mr *ibmr = NULL;
274 struct xlist_head *ret;
275 unsigned long *flag;
276
277 preempt_disable();
278 flag = &__get_cpu_var(clean_list_grace);
279 set_bit(CLEAN_LIST_BUSY_BIT, flag);
280 ret = xlist_del_head(&pool->clean_list);
281 if (ret)
282 ibmr = list_entry(ret, struct rds_ib_mr, xlist);
283
284 clear_bit(CLEAN_LIST_BUSY_BIT, flag);
285 preempt_enable();
286 return ibmr;
287}
288
289static inline void wait_clean_list_grace(void)
290{
291 int cpu;
292 unsigned long *flag;
293
294 for_each_online_cpu(cpu) {
295 flag = &per_cpu(clean_list_grace, cpu);
296 while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
297 cpu_relax();
298 }
299}
300
301static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev)
302{
303 struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
304 struct rds_ib_mr *ibmr = NULL;
305 int err = 0, iter = 0;
306
307 if (atomic_read(&pool->dirty_count) >= pool->max_items / 10)
308 schedule_delayed_work(&pool->flush_worker, 10);
309
310 while (1) {
311 ibmr = rds_ib_reuse_fmr(pool);
312 if (ibmr)
313 return ibmr;
314
315 /* No clean MRs - now we have the choice of either
316 * allocating a fresh MR up to the limit imposed by the
317 * driver, or flush any dirty unused MRs.
318 * We try to avoid stalling in the send path if possible,
319 * so we allocate as long as we're allowed to.
320 *
321 * We're fussy with enforcing the FMR limit, though. If the driver
322 * tells us we can't use more than N fmrs, we shouldn't start
323 * arguing with it */
324 if (atomic_inc_return(&pool->item_count) <= pool->max_items)
325 break;
326
327 atomic_dec(&pool->item_count);
328
329 if (++iter > 2) {
330 rds_ib_stats_inc(s_ib_rdma_mr_pool_depleted);
331 return ERR_PTR(-EAGAIN);
332 }
333
334 /* We do have some empty MRs. Flush them out. */
335 rds_ib_stats_inc(s_ib_rdma_mr_pool_wait);
336 rds_ib_flush_mr_pool(pool, 0, &ibmr);
337 if (ibmr)
338 return ibmr;
339 }
340
341 ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL, rdsibdev_to_node(rds_ibdev));
342 if (!ibmr) {
343 err = -ENOMEM;
344 goto out_no_cigar;
345 }
346
347 memset(ibmr, 0, sizeof(*ibmr));
348
349 ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
350 (IB_ACCESS_LOCAL_WRITE |
351 IB_ACCESS_REMOTE_READ |
352 IB_ACCESS_REMOTE_WRITE|
353 IB_ACCESS_REMOTE_ATOMIC),
354 &pool->fmr_attr);
355 if (IS_ERR(ibmr->fmr)) {
356 err = PTR_ERR(ibmr->fmr);
357 ibmr->fmr = NULL;
358 printk(KERN_WARNING "RDS/IB: ib_alloc_fmr failed (err=%d)\n", err);
359 goto out_no_cigar;
360 }
361
362 rds_ib_stats_inc(s_ib_rdma_mr_alloc);
363 return ibmr;
364
365out_no_cigar:
366 if (ibmr) {
367 if (ibmr->fmr)
368 ib_dealloc_fmr(ibmr->fmr);
369 kfree(ibmr);
370 }
371 atomic_dec(&pool->item_count);
372 return ERR_PTR(err);
373}
374
375static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
376 struct scatterlist *sg, unsigned int nents)
377{
378 struct ib_device *dev = rds_ibdev->dev;
379 struct scatterlist *scat = sg;
380 u64 io_addr = 0;
381 u64 *dma_pages;
382 u32 len;
383 int page_cnt, sg_dma_len;
384 int i, j;
385 int ret;
386
387 sg_dma_len = ib_dma_map_sg(dev, sg, nents,
388 DMA_BIDIRECTIONAL);
389 if (unlikely(!sg_dma_len)) {
390 printk(KERN_WARNING "RDS/IB: dma_map_sg failed!\n");
391 return -EBUSY;
392 }
393
394 len = 0;
395 page_cnt = 0;
396
397 for (i = 0; i < sg_dma_len; ++i) {
398 unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
399 u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
400
401 if (dma_addr & ~PAGE_MASK) {
402 if (i > 0)
403 return -EINVAL;
404 else
405 ++page_cnt;
406 }
407 if ((dma_addr + dma_len) & ~PAGE_MASK) {
408 if (i < sg_dma_len - 1)
409 return -EINVAL;
410 else
411 ++page_cnt;
412 }
413
414 len += dma_len;
415 }
416
417 page_cnt += len >> PAGE_SHIFT;
418 if (page_cnt > fmr_message_size)
419 return -EINVAL;
420
421 dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC,
422 rdsibdev_to_node(rds_ibdev));
423 if (!dma_pages)
424 return -ENOMEM;
425
426 page_cnt = 0;
427 for (i = 0; i < sg_dma_len; ++i) {
428 unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
429 u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
430
431 for (j = 0; j < dma_len; j += PAGE_SIZE)
432 dma_pages[page_cnt++] =
433 (dma_addr & PAGE_MASK) + j;
434 }
435
436 ret = ib_map_phys_fmr(ibmr->fmr,
437 dma_pages, page_cnt, io_addr);
438 if (ret)
439 goto out;
440
441 /* Success - we successfully remapped the MR, so we can
442 * safely tear down the old mapping. */
443 rds_ib_teardown_mr(ibmr);
444
445 ibmr->sg = scat;
446 ibmr->sg_len = nents;
447 ibmr->sg_dma_len = sg_dma_len;
448 ibmr->remap_count++;
449
450 rds_ib_stats_inc(s_ib_rdma_mr_used);
451 ret = 0;
452
453out:
454 kfree(dma_pages);
455
456 return ret;
457}
458
459void rds_ib_sync_mr(void *trans_private, int direction)
460{
461 struct rds_ib_mr *ibmr = trans_private;
462 struct rds_ib_device *rds_ibdev = ibmr->device;
463
464 switch (direction) {
465 case DMA_FROM_DEVICE:
466 ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
467 ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
468 break;
469 case DMA_TO_DEVICE:
470 ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
471 ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
472 break;
473 }
474}
475
476static void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
477{
478 struct rds_ib_device *rds_ibdev = ibmr->device;
479
480 if (ibmr->sg_dma_len) {
481 ib_dma_unmap_sg(rds_ibdev->dev,
482 ibmr->sg, ibmr->sg_len,
483 DMA_BIDIRECTIONAL);
484 ibmr->sg_dma_len = 0;
485 }
486
487 /* Release the s/g list */
488 if (ibmr->sg_len) {
489 unsigned int i;
490
491 for (i = 0; i < ibmr->sg_len; ++i) {
492 struct page *page = sg_page(&ibmr->sg[i]);
493
494 /* FIXME we need a way to tell a r/w MR
495 * from a r/o MR */
496 BUG_ON(irqs_disabled());
497 set_page_dirty(page);
498 put_page(page);
499 }
500 kfree(ibmr->sg);
501
502 ibmr->sg = NULL;
503 ibmr->sg_len = 0;
504 }
505}
506
507static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
508{
509 unsigned int pinned = ibmr->sg_len;
510
511 __rds_ib_teardown_mr(ibmr);
512 if (pinned) {
513 struct rds_ib_device *rds_ibdev = ibmr->device;
514 struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
515
516 atomic_sub(pinned, &pool->free_pinned);
517 }
518}
519
520static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
521{
522 unsigned int item_count;
523
524 item_count = atomic_read(&pool->item_count);
525 if (free_all)
526 return item_count;
527
528 return 0;
529}
530
531/*
532 * given an xlist of mrs, put them all into the list_head for more processing
533 */
534static void xlist_append_to_list(struct xlist_head *xlist, struct list_head *list)
535{
536 struct rds_ib_mr *ibmr;
537 struct xlist_head splice;
538 struct xlist_head *cur;
539 struct xlist_head *next;
540
541 splice.next = NULL;
542 xlist_splice(xlist, &splice);
543 cur = splice.next;
544 while (cur) {
545 next = cur->next;
546 ibmr = list_entry(cur, struct rds_ib_mr, xlist);
547 list_add_tail(&ibmr->unmap_list, list);
548 cur = next;
549 }
550}
551
552/*
553 * this takes a list head of mrs and turns it into an xlist of clusters.
554 * each cluster has an xlist of MR_CLUSTER_SIZE mrs that are ready for
555 * reuse.
556 */
557static void list_append_to_xlist(struct rds_ib_mr_pool *pool,
558 struct list_head *list, struct xlist_head *xlist,
559 struct xlist_head **tail_ret)
560{
561 struct rds_ib_mr *ibmr;
562 struct xlist_head *cur_mr = xlist;
563 struct xlist_head *tail_mr = NULL;
564
565 list_for_each_entry(ibmr, list, unmap_list) {
566 tail_mr = &ibmr->xlist;
567 tail_mr->next = NULL;
568 cur_mr->next = tail_mr;
569 cur_mr = tail_mr;
570 }
571 *tail_ret = tail_mr;
572}
573
574/*
575 * Flush our pool of MRs.
576 * At a minimum, all currently unused MRs are unmapped.
577 * If the number of MRs allocated exceeds the limit, we also try
578 * to free as many MRs as needed to get back to this limit.
579 */
580static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
581 int free_all, struct rds_ib_mr **ibmr_ret)
582{
583 struct rds_ib_mr *ibmr, *next;
584 struct xlist_head clean_xlist;
585 struct xlist_head *clean_tail;
586 LIST_HEAD(unmap_list);
587 LIST_HEAD(fmr_list);
588 unsigned long unpinned = 0;
589 unsigned int nfreed = 0, ncleaned = 0, free_goal;
590 int ret = 0;
591
592 rds_ib_stats_inc(s_ib_rdma_mr_pool_flush);
593
594 if (ibmr_ret) {
595 DEFINE_WAIT(wait);
596 while(!mutex_trylock(&pool->flush_lock)) {
597 ibmr = rds_ib_reuse_fmr(pool);
598 if (ibmr) {
599 *ibmr_ret = ibmr;
600 finish_wait(&pool->flush_wait, &wait);
601 goto out_nolock;
602 }
603
604 prepare_to_wait(&pool->flush_wait, &wait,
605 TASK_UNINTERRUPTIBLE);
606 if (xlist_empty(&pool->clean_list))
607 schedule();
608
609 ibmr = rds_ib_reuse_fmr(pool);
610 if (ibmr) {
611 *ibmr_ret = ibmr;
612 finish_wait(&pool->flush_wait, &wait);
613 goto out_nolock;
614 }
615 }
616 finish_wait(&pool->flush_wait, &wait);
617 } else
618 mutex_lock(&pool->flush_lock);
619
620 if (ibmr_ret) {
621 ibmr = rds_ib_reuse_fmr(pool);
622 if (ibmr) {
623 *ibmr_ret = ibmr;
624 goto out;
625 }
626 }
627
628 /* Get the list of all MRs to be dropped. Ordering matters -
629 * we want to put drop_list ahead of free_list.
630 */
631 xlist_append_to_list(&pool->drop_list, &unmap_list);
632 xlist_append_to_list(&pool->free_list, &unmap_list);
633 if (free_all)
634 xlist_append_to_list(&pool->clean_list, &unmap_list);
635
636 free_goal = rds_ib_flush_goal(pool, free_all);
637
638 if (list_empty(&unmap_list))
639 goto out;
640
641 /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
642 list_for_each_entry(ibmr, &unmap_list, unmap_list)
643 list_add(&ibmr->fmr->list, &fmr_list);
644
645 ret = ib_unmap_fmr(&fmr_list);
646 if (ret)
647 printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret);
648
649 /* Now we can destroy the DMA mapping and unpin any pages */
650 list_for_each_entry_safe(ibmr, next, &unmap_list, unmap_list) {
651 unpinned += ibmr->sg_len;
652 __rds_ib_teardown_mr(ibmr);
653 if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) {
654 rds_ib_stats_inc(s_ib_rdma_mr_free);
655 list_del(&ibmr->unmap_list);
656 ib_dealloc_fmr(ibmr->fmr);
657 kfree(ibmr);
658 nfreed++;
659 }
660 ncleaned++;
661 }
662
663 if (!list_empty(&unmap_list)) {
664 /* we have to make sure that none of the things we're about
665 * to put on the clean list would race with other cpus trying
666 * to pull items off. The xlist would explode if we managed to
667 * remove something from the clean list and then add it back again
668 * while another CPU was spinning on that same item in xlist_del_head.
669 *
670 * This is pretty unlikely, but just in case wait for an xlist grace period
671 * here before adding anything back into the clean list.
672 */
673 wait_clean_list_grace();
674
675 list_append_to_xlist(pool, &unmap_list, &clean_xlist, &clean_tail);
676 if (ibmr_ret)
677 refill_local(pool, &clean_xlist, ibmr_ret);
678
679 /* refill_local may have emptied our list */
680 if (!xlist_empty(&clean_xlist))
681 xlist_add(clean_xlist.next, clean_tail, &pool->clean_list);
682
683 }
684
685 atomic_sub(unpinned, &pool->free_pinned);
686 atomic_sub(ncleaned, &pool->dirty_count);
687 atomic_sub(nfreed, &pool->item_count);
688
689out:
690 mutex_unlock(&pool->flush_lock);
691 if (waitqueue_active(&pool->flush_wait))
692 wake_up(&pool->flush_wait);
693out_nolock:
694 return ret;
695}
696
697static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
698{
699 struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work);
700
701 rds_ib_flush_mr_pool(pool, 0, NULL);
702}
703
704void rds_ib_free_mr(void *trans_private, int invalidate)
705{
706 struct rds_ib_mr *ibmr = trans_private;
707 struct rds_ib_device *rds_ibdev = ibmr->device;
708 struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
709
710 rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
711
712 /* Return it to the pool's free list */
713 if (ibmr->remap_count >= pool->fmr_attr.max_maps)
714 xlist_add(&ibmr->xlist, &ibmr->xlist, &pool->drop_list);
715 else
716 xlist_add(&ibmr->xlist, &ibmr->xlist, &pool->free_list);
717
718 atomic_add(ibmr->sg_len, &pool->free_pinned);
719 atomic_inc(&pool->dirty_count);
720
721 /* If we've pinned too many pages, request a flush */
722 if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
723 atomic_read(&pool->dirty_count) >= pool->max_items / 10)
724 schedule_delayed_work(&pool->flush_worker, 10);
725
726 if (invalidate) {
727 if (likely(!in_interrupt())) {
728 rds_ib_flush_mr_pool(pool, 0, NULL);
729 } else {
730 /* We get here if the user created a MR marked
731 * as use_once and invalidate at the same time. */
732 schedule_delayed_work(&pool->flush_worker, 10);
733 }
734 }
735
736 rds_ib_dev_put(rds_ibdev);
737}
738
739void rds_ib_flush_mrs(void)
740{
741 struct rds_ib_device *rds_ibdev;
742
743 down_read(&rds_ib_devices_lock);
744 list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
745 struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
746
747 if (pool)
748 rds_ib_flush_mr_pool(pool, 0, NULL);
749 }
750 up_read(&rds_ib_devices_lock);
751}
752
753void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
754 struct rds_sock *rs, u32 *key_ret)
755{
756 struct rds_ib_device *rds_ibdev;
757 struct rds_ib_mr *ibmr = NULL;
758 int ret;
759
760 rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
761 if (!rds_ibdev) {
762 ret = -ENODEV;
763 goto out;
764 }
765
766 if (!rds_ibdev->mr_pool) {
767 ret = -ENODEV;
768 goto out;
769 }
770
771 ibmr = rds_ib_alloc_fmr(rds_ibdev);
772 if (IS_ERR(ibmr))
773 return ibmr;
774
775 ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
776 if (ret == 0)
777 *key_ret = ibmr->fmr->rkey;
778 else
779 printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret);
780
781 ibmr->device = rds_ibdev;
782 rds_ibdev = NULL;
783
784 out:
785 if (ret) {
786 if (ibmr)
787 rds_ib_free_mr(ibmr, 0);
788 ibmr = ERR_PTR(ret);
789 }
790 if (rds_ibdev)
791 rds_ib_dev_put(rds_ibdev);
792 return ibmr;
793}
794