819c35a0d9cbf9fa8527ba3668e2f80ca304676e
[linux-2.6.git] / net / rds / ib_rdma.c
1 /*
2  * Copyright (c) 2006 Oracle.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/rculist.h>
36
37 #include "rds.h"
38 #include "ib.h"
39 #include "xlist.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 {
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  */
67 struct 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
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
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
201 void 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
215 struct 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
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
254 void 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
263 static 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
271 static 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
289 static 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
301 static 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
365 out_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
375 static 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
453 out:
454         kfree(dma_pages);
455
456         return ret;
457 }
458
459 void 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
476 static 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
507 static 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
520 static 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  */
534 static 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  */
557 static 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  */
580 static 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
689 out:
690         mutex_unlock(&pool->flush_lock);
691         if (waitqueue_active(&pool->flush_wait))
692                 wake_up(&pool->flush_wait);
693 out_nolock:
694         return ret;
695 }
696
697 static 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
704 void 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
739 void 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
753 void *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