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v5.9
  1/*
  2 * Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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_single_path.h"
 39#include "ib_mr.h"
 40#include "rds.h"
 
 
 41
 42struct workqueue_struct *rds_ib_mr_wq;
 43struct rds_ib_dereg_odp_mr {
 44	struct work_struct work;
 45	struct ib_mr *mr;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 46};
 47
 48static void rds_ib_odp_mr_worker(struct work_struct *work);
 
 
 49
 50static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
 51{
 52	struct rds_ib_device *rds_ibdev;
 53	struct rds_ib_ipaddr *i_ipaddr;
 54
 55	rcu_read_lock();
 56	list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) {
 57		list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
 58			if (i_ipaddr->ipaddr == ipaddr) {
 59				refcount_inc(&rds_ibdev->refcount);
 60				rcu_read_unlock();
 61				return rds_ibdev;
 62			}
 63		}
 64	}
 65	rcu_read_unlock();
 66
 67	return NULL;
 68}
 69
 70static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
 71{
 72	struct rds_ib_ipaddr *i_ipaddr;
 73
 74	i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
 75	if (!i_ipaddr)
 76		return -ENOMEM;
 77
 78	i_ipaddr->ipaddr = ipaddr;
 79
 80	spin_lock_irq(&rds_ibdev->spinlock);
 81	list_add_tail_rcu(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
 82	spin_unlock_irq(&rds_ibdev->spinlock);
 83
 84	return 0;
 85}
 86
 87static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
 88{
 89	struct rds_ib_ipaddr *i_ipaddr;
 90	struct rds_ib_ipaddr *to_free = NULL;
 91
 92
 93	spin_lock_irq(&rds_ibdev->spinlock);
 94	list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
 95		if (i_ipaddr->ipaddr == ipaddr) {
 96			list_del_rcu(&i_ipaddr->list);
 97			to_free = i_ipaddr;
 98			break;
 99		}
100	}
101	spin_unlock_irq(&rds_ibdev->spinlock);
102
103	if (to_free)
104		kfree_rcu(to_free, rcu);
 
 
105}
106
107int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
108			 struct in6_addr *ipaddr)
109{
110	struct rds_ib_device *rds_ibdev_old;
111
112	rds_ibdev_old = rds_ib_get_device(ipaddr->s6_addr32[3]);
113	if (!rds_ibdev_old)
114		return rds_ib_add_ipaddr(rds_ibdev, ipaddr->s6_addr32[3]);
115
116	if (rds_ibdev_old != rds_ibdev) {
117		rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr->s6_addr32[3]);
118		rds_ib_dev_put(rds_ibdev_old);
119		return rds_ib_add_ipaddr(rds_ibdev, ipaddr->s6_addr32[3]);
120	}
121	rds_ib_dev_put(rds_ibdev_old);
122
123	return 0;
124}
125
126void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
127{
128	struct rds_ib_connection *ic = conn->c_transport_data;
129
130	/* conn was previously on the nodev_conns_list */
131	spin_lock_irq(&ib_nodev_conns_lock);
132	BUG_ON(list_empty(&ib_nodev_conns));
133	BUG_ON(list_empty(&ic->ib_node));
134	list_del(&ic->ib_node);
135
136	spin_lock(&rds_ibdev->spinlock);
137	list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
138	spin_unlock(&rds_ibdev->spinlock);
139	spin_unlock_irq(&ib_nodev_conns_lock);
140
141	ic->rds_ibdev = rds_ibdev;
142	refcount_inc(&rds_ibdev->refcount);
143}
144
145void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
146{
147	struct rds_ib_connection *ic = conn->c_transport_data;
148
149	/* place conn on nodev_conns_list */
150	spin_lock(&ib_nodev_conns_lock);
151
152	spin_lock_irq(&rds_ibdev->spinlock);
153	BUG_ON(list_empty(&ic->ib_node));
154	list_del(&ic->ib_node);
155	spin_unlock_irq(&rds_ibdev->spinlock);
156
157	list_add_tail(&ic->ib_node, &ib_nodev_conns);
158
159	spin_unlock(&ib_nodev_conns_lock);
160
161	ic->rds_ibdev = NULL;
162	rds_ib_dev_put(rds_ibdev);
163}
164
165void rds_ib_destroy_nodev_conns(void)
166{
167	struct rds_ib_connection *ic, *_ic;
168	LIST_HEAD(tmp_list);
169
170	/* avoid calling conn_destroy with irqs off */
171	spin_lock_irq(&ib_nodev_conns_lock);
172	list_splice(&ib_nodev_conns, &tmp_list);
173	spin_unlock_irq(&ib_nodev_conns_lock);
174
175	list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
176		rds_conn_destroy(ic->conn);
177}
178
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
179void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
180{
181	struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
182
183	iinfo->rdma_mr_max = pool_1m->max_items;
184	iinfo->rdma_mr_size = pool_1m->max_pages;
185}
186
187#if IS_ENABLED(CONFIG_IPV6)
188void rds6_ib_get_mr_info(struct rds_ib_device *rds_ibdev,
189			 struct rds6_info_rdma_connection *iinfo6)
190{
191	struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
 
 
 
 
 
192
193	iinfo6->rdma_mr_max = pool_1m->max_items;
194	iinfo6->rdma_mr_size = pool_1m->max_pages;
 
 
 
 
195}
196#endif
197
198struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *pool)
199{
200	struct rds_ib_mr *ibmr = NULL;
201	struct llist_node *ret;
202	unsigned long flags;
203
204	spin_lock_irqsave(&pool->clean_lock, flags);
205	ret = llist_del_first(&pool->clean_list);
206	spin_unlock_irqrestore(&pool->clean_lock, flags);
207	if (ret) {
208		ibmr = llist_entry(ret, struct rds_ib_mr, llnode);
209		if (pool->pool_type == RDS_IB_MR_8K_POOL)
210			rds_ib_stats_inc(s_ib_rdma_mr_8k_reused);
211		else
212			rds_ib_stats_inc(s_ib_rdma_mr_1m_reused);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
213	}
214
 
215	return ibmr;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
216}
217
218void rds_ib_sync_mr(void *trans_private, int direction)
219{
220	struct rds_ib_mr *ibmr = trans_private;
221	struct rds_ib_device *rds_ibdev = ibmr->device;
222
223	if (ibmr->odp)
224		return;
225
226	switch (direction) {
227	case DMA_FROM_DEVICE:
228		ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
229			ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
230		break;
231	case DMA_TO_DEVICE:
232		ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
233			ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
234		break;
235	}
236}
237
238void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
239{
240	struct rds_ib_device *rds_ibdev = ibmr->device;
241
242	if (ibmr->sg_dma_len) {
243		ib_dma_unmap_sg(rds_ibdev->dev,
244				ibmr->sg, ibmr->sg_len,
245				DMA_BIDIRECTIONAL);
246		ibmr->sg_dma_len = 0;
247	}
248
249	/* Release the s/g list */
250	if (ibmr->sg_len) {
251		unsigned int i;
252
253		for (i = 0; i < ibmr->sg_len; ++i) {
254			struct page *page = sg_page(&ibmr->sg[i]);
255
256			/* FIXME we need a way to tell a r/w MR
257			 * from a r/o MR */
258			WARN_ON(!page->mapping && irqs_disabled());
259			set_page_dirty(page);
260			put_page(page);
261		}
262		kfree(ibmr->sg);
263
264		ibmr->sg = NULL;
265		ibmr->sg_len = 0;
266	}
267}
268
269void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
270{
271	unsigned int pinned = ibmr->sg_len;
272
273	__rds_ib_teardown_mr(ibmr);
274	if (pinned) {
275		struct rds_ib_mr_pool *pool = ibmr->pool;
 
276
277		atomic_sub(pinned, &pool->free_pinned);
278	}
279}
280
281static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
282{
283	unsigned int item_count;
284
285	item_count = atomic_read(&pool->item_count);
286	if (free_all)
287		return item_count;
288
289	return 0;
290}
291
292/*
293 * given an llist of mrs, put them all into the list_head for more processing
294 */
295static unsigned int llist_append_to_list(struct llist_head *llist,
296					 struct list_head *list)
297{
298	struct rds_ib_mr *ibmr;
299	struct llist_node *node;
300	struct llist_node *next;
301	unsigned int count = 0;
302
303	node = llist_del_all(llist);
304	while (node) {
305		next = node->next;
306		ibmr = llist_entry(node, struct rds_ib_mr, llnode);
 
 
307		list_add_tail(&ibmr->unmap_list, list);
308		node = next;
309		count++;
310	}
311	return count;
312}
313
314/*
315 * this takes a list head of mrs and turns it into linked llist nodes
316 * of clusters.  Each cluster has linked llist nodes of
317 * MR_CLUSTER_SIZE mrs that are ready for reuse.
318 */
319static void list_to_llist_nodes(struct list_head *list,
320				struct llist_node **nodes_head,
321				struct llist_node **nodes_tail)
322{
323	struct rds_ib_mr *ibmr;
324	struct llist_node *cur = NULL;
325	struct llist_node **next = nodes_head;
326
327	list_for_each_entry(ibmr, list, unmap_list) {
328		cur = &ibmr->llnode;
329		*next = cur;
330		next = &cur->next;
 
331	}
332	*next = NULL;
333	*nodes_tail = cur;
334}
335
336/*
337 * Flush our pool of MRs.
338 * At a minimum, all currently unused MRs are unmapped.
339 * If the number of MRs allocated exceeds the limit, we also try
340 * to free as many MRs as needed to get back to this limit.
341 */
342int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
343			 int free_all, struct rds_ib_mr **ibmr_ret)
344{
345	struct rds_ib_mr *ibmr;
346	struct llist_node *clean_nodes;
347	struct llist_node *clean_tail;
348	LIST_HEAD(unmap_list);
 
349	unsigned long unpinned = 0;
350	unsigned int nfreed = 0, dirty_to_clean = 0, free_goal;
 
351
352	if (pool->pool_type == RDS_IB_MR_8K_POOL)
353		rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_flush);
354	else
355		rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_flush);
356
357	if (ibmr_ret) {
358		DEFINE_WAIT(wait);
359		while (!mutex_trylock(&pool->flush_lock)) {
360			ibmr = rds_ib_reuse_mr(pool);
361			if (ibmr) {
362				*ibmr_ret = ibmr;
363				finish_wait(&pool->flush_wait, &wait);
364				goto out_nolock;
365			}
366
367			prepare_to_wait(&pool->flush_wait, &wait,
368					TASK_UNINTERRUPTIBLE);
369			if (llist_empty(&pool->clean_list))
370				schedule();
371
372			ibmr = rds_ib_reuse_mr(pool);
373			if (ibmr) {
374				*ibmr_ret = ibmr;
375				finish_wait(&pool->flush_wait, &wait);
376				goto out_nolock;
377			}
378		}
379		finish_wait(&pool->flush_wait, &wait);
380	} else
381		mutex_lock(&pool->flush_lock);
382
383	if (ibmr_ret) {
384		ibmr = rds_ib_reuse_mr(pool);
385		if (ibmr) {
386			*ibmr_ret = ibmr;
387			goto out;
388		}
389	}
390
391	/* Get the list of all MRs to be dropped. Ordering matters -
392	 * we want to put drop_list ahead of free_list.
393	 */
394	dirty_to_clean = llist_append_to_list(&pool->drop_list, &unmap_list);
395	dirty_to_clean += llist_append_to_list(&pool->free_list, &unmap_list);
396	if (free_all) {
397		unsigned long flags;
398
399		spin_lock_irqsave(&pool->clean_lock, flags);
400		llist_append_to_list(&pool->clean_list, &unmap_list);
401		spin_unlock_irqrestore(&pool->clean_lock, flags);
402	}
403
404	free_goal = rds_ib_flush_goal(pool, free_all);
405
406	if (list_empty(&unmap_list))
407		goto out;
408
409	rds_ib_unreg_frmr(&unmap_list, &nfreed, &unpinned, free_goal);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
410
411	if (!list_empty(&unmap_list)) {
412		unsigned long flags;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
413
414		list_to_llist_nodes(&unmap_list, &clean_nodes, &clean_tail);
415		if (ibmr_ret) {
416			*ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode);
417			clean_nodes = clean_nodes->next;
418		}
419		/* more than one entry in llist nodes */
420		if (clean_nodes) {
421			spin_lock_irqsave(&pool->clean_lock, flags);
422			llist_add_batch(clean_nodes, clean_tail,
423					&pool->clean_list);
424			spin_unlock_irqrestore(&pool->clean_lock, flags);
425		}
426	}
427
428	atomic_sub(unpinned, &pool->free_pinned);
429	atomic_sub(dirty_to_clean, &pool->dirty_count);
430	atomic_sub(nfreed, &pool->item_count);
431
432out:
433	mutex_unlock(&pool->flush_lock);
434	if (waitqueue_active(&pool->flush_wait))
435		wake_up(&pool->flush_wait);
436out_nolock:
437	return 0;
438}
439
440struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *pool)
441{
442	struct rds_ib_mr *ibmr = NULL;
443	int iter = 0;
444
445	while (1) {
446		ibmr = rds_ib_reuse_mr(pool);
447		if (ibmr)
448			return ibmr;
449
450		if (atomic_inc_return(&pool->item_count) <= pool->max_items)
451			break;
452
453		atomic_dec(&pool->item_count);
454
455		if (++iter > 2) {
456			if (pool->pool_type == RDS_IB_MR_8K_POOL)
457				rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_depleted);
458			else
459				rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_depleted);
460			break;
461		}
462
463		/* We do have some empty MRs. Flush them out. */
464		if (pool->pool_type == RDS_IB_MR_8K_POOL)
465			rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_wait);
466		else
467			rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_wait);
468
469		rds_ib_flush_mr_pool(pool, 0, &ibmr);
470		if (ibmr)
471			return ibmr;
472	}
473
474	return NULL;
475}
476
477static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
478{
479	struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work);
480
481	rds_ib_flush_mr_pool(pool, 0, NULL);
482}
483
484void rds_ib_free_mr(void *trans_private, int invalidate)
485{
486	struct rds_ib_mr *ibmr = trans_private;
487	struct rds_ib_mr_pool *pool = ibmr->pool;
488	struct rds_ib_device *rds_ibdev = ibmr->device;
 
489
490	rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
491
492	if (ibmr->odp) {
493		/* A MR created and marked as use_once. We use delayed work,
494		 * because there is a change that we are in interrupt and can't
495		 * call to ib_dereg_mr() directly.
496		 */
497		INIT_DELAYED_WORK(&ibmr->work, rds_ib_odp_mr_worker);
498		queue_delayed_work(rds_ib_mr_wq, &ibmr->work, 0);
499		return;
500	}
501
502	/* Return it to the pool's free list */
503	rds_ib_free_frmr_list(ibmr);
 
 
 
504
505	atomic_add(ibmr->sg_len, &pool->free_pinned);
506	atomic_inc(&pool->dirty_count);
507
508	/* If we've pinned too many pages, request a flush */
509	if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
510	    atomic_read(&pool->dirty_count) >= pool->max_items / 5)
511		queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
512
513	if (invalidate) {
514		if (likely(!in_interrupt())) {
515			rds_ib_flush_mr_pool(pool, 0, NULL);
516		} else {
517			/* We get here if the user created a MR marked
518			 * as use_once and invalidate at the same time.
519			 */
520			queue_delayed_work(rds_ib_mr_wq,
521					   &pool->flush_worker, 10);
522		}
523	}
524
525	rds_ib_dev_put(rds_ibdev);
526}
527
528void rds_ib_flush_mrs(void)
529{
530	struct rds_ib_device *rds_ibdev;
531
532	down_read(&rds_ib_devices_lock);
533	list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
534		if (rds_ibdev->mr_8k_pool)
535			rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 0, NULL);
536
537		if (rds_ibdev->mr_1m_pool)
538			rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 0, NULL);
539	}
540	up_read(&rds_ib_devices_lock);
541}
542
543u32 rds_ib_get_lkey(void *trans_private)
544{
545	struct rds_ib_mr *ibmr = trans_private;
546
547	return ibmr->u.mr->lkey;
548}
549
550void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
551		    struct rds_sock *rs, u32 *key_ret,
552		    struct rds_connection *conn,
553		    u64 start, u64 length, int need_odp)
554{
555	struct rds_ib_device *rds_ibdev;
556	struct rds_ib_mr *ibmr = NULL;
557	struct rds_ib_connection *ic = NULL;
558	int ret;
559
560	rds_ibdev = rds_ib_get_device(rs->rs_bound_addr.s6_addr32[3]);
561	if (!rds_ibdev) {
562		ret = -ENODEV;
563		goto out;
564	}
565
566	if (need_odp == ODP_ZEROBASED || need_odp == ODP_VIRTUAL) {
567		u64 virt_addr = need_odp == ODP_ZEROBASED ? 0 : start;
568		int access_flags =
569			(IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
570			 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_ATOMIC |
571			 IB_ACCESS_ON_DEMAND);
572		struct ib_sge sge = {};
573		struct ib_mr *ib_mr;
574
575		if (!rds_ibdev->odp_capable) {
576			ret = -EOPNOTSUPP;
577			goto out;
578		}
579
580		ib_mr = ib_reg_user_mr(rds_ibdev->pd, start, length, virt_addr,
581				       access_flags);
582
583		if (IS_ERR(ib_mr)) {
584			rdsdebug("rds_ib_get_user_mr returned %d\n",
585				 IS_ERR(ib_mr));
586			ret = PTR_ERR(ib_mr);
587			goto out;
588		}
589		if (key_ret)
590			*key_ret = ib_mr->rkey;
591
592		ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
593		if (!ibmr) {
594			ib_dereg_mr(ib_mr);
595			ret = -ENOMEM;
596			goto out;
597		}
598		ibmr->u.mr = ib_mr;
599		ibmr->odp = 1;
600
601		sge.addr = virt_addr;
602		sge.length = length;
603		sge.lkey = ib_mr->lkey;
604
605		ib_advise_mr(rds_ibdev->pd,
606			     IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE,
607			     IB_UVERBS_ADVISE_MR_FLAG_FLUSH, &sge, 1);
608		return ibmr;
609	}
610
611	if (conn)
612		ic = conn->c_transport_data;
613
614	if (!rds_ibdev->mr_8k_pool || !rds_ibdev->mr_1m_pool) {
615		ret = -ENODEV;
616		goto out;
617	}
618
619	ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
620	if (IS_ERR(ibmr)) {
621		ret = PTR_ERR(ibmr);
622		pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret);
623	} else {
624		return ibmr;
625	}
626
627 out:
628	if (rds_ibdev)
629		rds_ib_dev_put(rds_ibdev);
630
631	return ERR_PTR(ret);
632}
633
634void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
635{
636	cancel_delayed_work_sync(&pool->flush_worker);
637	rds_ib_flush_mr_pool(pool, 1, NULL);
638	WARN_ON(atomic_read(&pool->item_count));
639	WARN_ON(atomic_read(&pool->free_pinned));
640	kfree(pool);
641}
642
643struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev,
644					     int pool_type)
645{
646	struct rds_ib_mr_pool *pool;
647
648	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
649	if (!pool)
650		return ERR_PTR(-ENOMEM);
651
652	pool->pool_type = pool_type;
653	init_llist_head(&pool->free_list);
654	init_llist_head(&pool->drop_list);
655	init_llist_head(&pool->clean_list);
656	spin_lock_init(&pool->clean_lock);
657	mutex_init(&pool->flush_lock);
658	init_waitqueue_head(&pool->flush_wait);
659	INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
660
661	if (pool_type == RDS_IB_MR_1M_POOL) {
662		/* +1 allows for unaligned MRs */
663		pool->max_pages = RDS_MR_1M_MSG_SIZE + 1;
664		pool->max_items = rds_ibdev->max_1m_mrs;
665	} else {
666		/* pool_type == RDS_IB_MR_8K_POOL */
667		pool->max_pages = RDS_MR_8K_MSG_SIZE + 1;
668		pool->max_items = rds_ibdev->max_8k_mrs;
669	}
670
671	pool->max_free_pinned = pool->max_items * pool->max_pages / 4;
672	pool->max_items_soft = rds_ibdev->max_mrs * 3 / 4;
673
674	return pool;
675}
676
677int rds_ib_mr_init(void)
678{
679	rds_ib_mr_wq = alloc_workqueue("rds_mr_flushd", WQ_MEM_RECLAIM, 0);
680	if (!rds_ib_mr_wq)
681		return -ENOMEM;
682	return 0;
683}
684
685/* By the time this is called all the IB devices should have been torn down and
686 * had their pools freed.  As each pool is freed its work struct is waited on,
687 * so the pool flushing work queue should be idle by the time we get here.
688 */
689void rds_ib_mr_exit(void)
690{
691	destroy_workqueue(rds_ib_mr_wq);
692}
693
694static void rds_ib_odp_mr_worker(struct work_struct  *work)
695{
696	struct rds_ib_mr *ibmr;
697
698	ibmr = container_of(work, struct rds_ib_mr, work.work);
699	ib_dereg_mr(ibmr->u.mr);
700	kfree(ibmr);
701}
v3.1
  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