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/ratelimit.h>
36
37 #include "rds.h"
38 #include "iw.h"
39
40
41 /*
42 * This is stored as mr->r_trans_private.
43 */
44 struct rds_iw_mr {
45 struct rds_iw_device *device;
46 struct rds_iw_mr_pool *pool;
47 struct rdma_cm_id *cm_id;
48
49 struct ib_mr *mr;
50 struct ib_fast_reg_page_list *page_list;
51
52 struct rds_iw_mapping mapping;
53 unsigned char remap_count;
54 };
55
56 /*
57 * Our own little MR pool
58 */
59 struct rds_iw_mr_pool {
60 struct rds_iw_device *device; /* back ptr to the device that owns us */
61
62 struct mutex flush_lock; /* serialize fmr invalidate */
63 struct work_struct flush_worker; /* flush worker */
64
65 spinlock_t list_lock; /* protect variables below */
66 atomic_t item_count; /* total # of MRs */
67 atomic_t dirty_count; /* # dirty of MRs */
68 struct list_head dirty_list; /* dirty mappings */
69 struct list_head clean_list; /* unused & unamapped MRs */
70 atomic_t free_pinned; /* memory pinned by free MRs */
71 unsigned long max_message_size; /* in pages */
72 unsigned long max_items;
73 unsigned long max_items_soft;
74 unsigned long max_free_pinned;
75 int max_pages;
76 };
77
78 static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all);
79 static void rds_iw_mr_pool_flush_worker(struct work_struct *work);
80 static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
81 static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
82 struct rds_iw_mr *ibmr,
83 struct scatterlist *sg, unsigned int nents);
84 static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
85 static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
86 struct list_head *unmap_list,
87 struct list_head *kill_list,
88 int *unpinned);
89 static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);
90
rds_iw_get_device(struct sockaddr_in * src,struct sockaddr_in * dst,struct rds_iw_device ** rds_iwdev,struct rdma_cm_id ** cm_id)91 static int rds_iw_get_device(struct sockaddr_in *src, struct sockaddr_in *dst,
92 struct rds_iw_device **rds_iwdev,
93 struct rdma_cm_id **cm_id)
94 {
95 struct rds_iw_device *iwdev;
96 struct rds_iw_cm_id *i_cm_id;
97
98 *rds_iwdev = NULL;
99 *cm_id = NULL;
100
101 list_for_each_entry(iwdev, &rds_iw_devices, list) {
102 spin_lock_irq(&iwdev->spinlock);
103 list_for_each_entry(i_cm_id, &iwdev->cm_id_list, list) {
104 struct sockaddr_in *src_addr, *dst_addr;
105
106 src_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.src_addr;
107 dst_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.dst_addr;
108
109 rdsdebug("local ipaddr = %x port %d, "
110 "remote ipaddr = %x port %d"
111 "..looking for %x port %d, "
112 "remote ipaddr = %x port %d\n",
113 src_addr->sin_addr.s_addr,
114 src_addr->sin_port,
115 dst_addr->sin_addr.s_addr,
116 dst_addr->sin_port,
117 src->sin_addr.s_addr,
118 src->sin_port,
119 dst->sin_addr.s_addr,
120 dst->sin_port);
121 #ifdef WORKING_TUPLE_DETECTION
122 if (src_addr->sin_addr.s_addr == src->sin_addr.s_addr &&
123 src_addr->sin_port == src->sin_port &&
124 dst_addr->sin_addr.s_addr == dst->sin_addr.s_addr &&
125 dst_addr->sin_port == dst->sin_port) {
126 #else
127 /* FIXME - needs to compare the local and remote
128 * ipaddr/port tuple, but the ipaddr is the only
129 * available information in the rds_sock (as the rest are
130 * zero'ed. It doesn't appear to be properly populated
131 * during connection setup...
132 */
133 if (src_addr->sin_addr.s_addr == src->sin_addr.s_addr) {
134 #endif
135 spin_unlock_irq(&iwdev->spinlock);
136 *rds_iwdev = iwdev;
137 *cm_id = i_cm_id->cm_id;
138 return 0;
139 }
140 }
141 spin_unlock_irq(&iwdev->spinlock);
142 }
143
144 return 1;
145 }
146
147 static int rds_iw_add_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
148 {
149 struct rds_iw_cm_id *i_cm_id;
150
151 i_cm_id = kmalloc(sizeof *i_cm_id, GFP_KERNEL);
152 if (!i_cm_id)
153 return -ENOMEM;
154
155 i_cm_id->cm_id = cm_id;
156
157 spin_lock_irq(&rds_iwdev->spinlock);
158 list_add_tail(&i_cm_id->list, &rds_iwdev->cm_id_list);
159 spin_unlock_irq(&rds_iwdev->spinlock);
160
161 return 0;
162 }
163
164 static void rds_iw_remove_cm_id(struct rds_iw_device *rds_iwdev,
165 struct rdma_cm_id *cm_id)
166 {
167 struct rds_iw_cm_id *i_cm_id;
168
169 spin_lock_irq(&rds_iwdev->spinlock);
170 list_for_each_entry(i_cm_id, &rds_iwdev->cm_id_list, list) {
171 if (i_cm_id->cm_id == cm_id) {
172 list_del(&i_cm_id->list);
173 kfree(i_cm_id);
174 break;
175 }
176 }
177 spin_unlock_irq(&rds_iwdev->spinlock);
178 }
179
180
181 int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id)
182 {
183 struct sockaddr_in *src_addr, *dst_addr;
184 struct rds_iw_device *rds_iwdev_old;
185 struct rdma_cm_id *pcm_id;
186 int rc;
187
188 src_addr = (struct sockaddr_in *)&cm_id->route.addr.src_addr;
189 dst_addr = (struct sockaddr_in *)&cm_id->route.addr.dst_addr;
190
191 rc = rds_iw_get_device(src_addr, dst_addr, &rds_iwdev_old, &pcm_id);
192 if (rc)
193 rds_iw_remove_cm_id(rds_iwdev, cm_id);
194
195 return rds_iw_add_cm_id(rds_iwdev, cm_id);
196 }
197
198 void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
199 {
200 struct rds_iw_connection *ic = conn->c_transport_data;
201
202 /* conn was previously on the nodev_conns_list */
203 spin_lock_irq(&iw_nodev_conns_lock);
204 BUG_ON(list_empty(&iw_nodev_conns));
205 BUG_ON(list_empty(&ic->iw_node));
206 list_del(&ic->iw_node);
207
208 spin_lock(&rds_iwdev->spinlock);
209 list_add_tail(&ic->iw_node, &rds_iwdev->conn_list);
210 spin_unlock(&rds_iwdev->spinlock);
211 spin_unlock_irq(&iw_nodev_conns_lock);
212
213 ic->rds_iwdev = rds_iwdev;
214 }
215
216 void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn)
217 {
218 struct rds_iw_connection *ic = conn->c_transport_data;
219
220 /* place conn on nodev_conns_list */
221 spin_lock(&iw_nodev_conns_lock);
222
223 spin_lock_irq(&rds_iwdev->spinlock);
224 BUG_ON(list_empty(&ic->iw_node));
225 list_del(&ic->iw_node);
226 spin_unlock_irq(&rds_iwdev->spinlock);
227
228 list_add_tail(&ic->iw_node, &iw_nodev_conns);
229
230 spin_unlock(&iw_nodev_conns_lock);
231
232 rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id);
233 ic->rds_iwdev = NULL;
234 }
235
236 void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock)
237 {
238 struct rds_iw_connection *ic, *_ic;
239 LIST_HEAD(tmp_list);
240
241 /* avoid calling conn_destroy with irqs off */
242 spin_lock_irq(list_lock);
243 list_splice(list, &tmp_list);
244 INIT_LIST_HEAD(list);
245 spin_unlock_irq(list_lock);
246
247 list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node)
248 rds_conn_destroy(ic->conn);
249 }
250
251 static void rds_iw_set_scatterlist(struct rds_iw_scatterlist *sg,
252 struct scatterlist *list, unsigned int sg_len)
253 {
254 sg->list = list;
255 sg->len = sg_len;
256 sg->dma_len = 0;
257 sg->dma_npages = 0;
258 sg->bytes = 0;
259 }
260
261 static u64 *rds_iw_map_scatterlist(struct rds_iw_device *rds_iwdev,
262 struct rds_iw_scatterlist *sg)
263 {
264 struct ib_device *dev = rds_iwdev->dev;
265 u64 *dma_pages = NULL;
266 int i, j, ret;
267
268 WARN_ON(sg->dma_len);
269
270 sg->dma_len = ib_dma_map_sg(dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
271 if (unlikely(!sg->dma_len)) {
272 printk(KERN_WARNING "RDS/IW: dma_map_sg failed!\n");
273 return ERR_PTR(-EBUSY);
274 }
275
276 sg->bytes = 0;
277 sg->dma_npages = 0;
278
279 ret = -EINVAL;
280 for (i = 0; i < sg->dma_len; ++i) {
281 unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
282 u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
283 u64 end_addr;
284
285 sg->bytes += dma_len;
286
287 end_addr = dma_addr + dma_len;
288 if (dma_addr & PAGE_MASK) {
289 if (i > 0)
290 goto out_unmap;
291 dma_addr &= ~PAGE_MASK;
292 }
293 if (end_addr & PAGE_MASK) {
294 if (i < sg->dma_len - 1)
295 goto out_unmap;
296 end_addr = (end_addr + PAGE_MASK) & ~PAGE_MASK;
297 }
298
299 sg->dma_npages += (end_addr - dma_addr) >> PAGE_SHIFT;
300 }
301
302 /* Now gather the dma addrs into one list */
303 if (sg->dma_npages > fastreg_message_size)
304 goto out_unmap;
305
306 dma_pages = kmalloc(sizeof(u64) * sg->dma_npages, GFP_ATOMIC);
307 if (!dma_pages) {
308 ret = -ENOMEM;
309 goto out_unmap;
310 }
311
312 for (i = j = 0; i < sg->dma_len; ++i) {
313 unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]);
314 u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]);
315 u64 end_addr;
316
317 end_addr = dma_addr + dma_len;
318 dma_addr &= ~PAGE_MASK;
319 for (; dma_addr < end_addr; dma_addr += PAGE_SIZE)
320 dma_pages[j++] = dma_addr;
321 BUG_ON(j > sg->dma_npages);
322 }
323
324 return dma_pages;
325
326 out_unmap:
327 ib_dma_unmap_sg(rds_iwdev->dev, sg->list, sg->len, DMA_BIDIRECTIONAL);
328 sg->dma_len = 0;
329 kfree(dma_pages);
330 return ERR_PTR(ret);
331 }
332
333
334 struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *rds_iwdev)
335 {
336 struct rds_iw_mr_pool *pool;
337
338 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
339 if (!pool) {
340 printk(KERN_WARNING "RDS/IW: rds_iw_create_mr_pool alloc error\n");
341 return ERR_PTR(-ENOMEM);
342 }
343
344 pool->device = rds_iwdev;
345 INIT_LIST_HEAD(&pool->dirty_list);
346 INIT_LIST_HEAD(&pool->clean_list);
347 mutex_init(&pool->flush_lock);
348 spin_lock_init(&pool->list_lock);
349 INIT_WORK(&pool->flush_worker, rds_iw_mr_pool_flush_worker);
350
351 pool->max_message_size = fastreg_message_size;
352 pool->max_items = fastreg_pool_size;
353 pool->max_free_pinned = pool->max_items * pool->max_message_size / 4;
354 pool->max_pages = fastreg_message_size;
355
356 /* We never allow more than max_items MRs to be allocated.
357 * When we exceed more than max_items_soft, we start freeing
358 * items more aggressively.
359 * Make sure that max_items > max_items_soft > max_items / 2
360 */
361 pool->max_items_soft = pool->max_items * 3 / 4;
362
363 return pool;
364 }
365
366 void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo)
367 {
368 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
369
370 iinfo->rdma_mr_max = pool->max_items;
371 iinfo->rdma_mr_size = pool->max_pages;
372 }
373
374 void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *pool)
375 {
376 flush_workqueue(rds_wq);
377 rds_iw_flush_mr_pool(pool, 1);
378 BUG_ON(atomic_read(&pool->item_count));
379 BUG_ON(atomic_read(&pool->free_pinned));
380 kfree(pool);
381 }
382
383 static inline struct rds_iw_mr *rds_iw_reuse_fmr(struct rds_iw_mr_pool *pool)
384 {
385 struct rds_iw_mr *ibmr = NULL;
386 unsigned long flags;
387
388 spin_lock_irqsave(&pool->list_lock, flags);
389 if (!list_empty(&pool->clean_list)) {
390 ibmr = list_entry(pool->clean_list.next, struct rds_iw_mr, mapping.m_list);
391 list_del_init(&ibmr->mapping.m_list);
392 }
393 spin_unlock_irqrestore(&pool->list_lock, flags);
394
395 return ibmr;
396 }
397
398 static struct rds_iw_mr *rds_iw_alloc_mr(struct rds_iw_device *rds_iwdev)
399 {
400 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
401 struct rds_iw_mr *ibmr = NULL;
402 int err = 0, iter = 0;
403
404 while (1) {
405 ibmr = rds_iw_reuse_fmr(pool);
406 if (ibmr)
407 return ibmr;
408
409 /* No clean MRs - now we have the choice of either
410 * allocating a fresh MR up to the limit imposed by the
411 * driver, or flush any dirty unused MRs.
412 * We try to avoid stalling in the send path if possible,
413 * so we allocate as long as we're allowed to.
414 *
415 * We're fussy with enforcing the FMR limit, though. If the driver
416 * tells us we can't use more than N fmrs, we shouldn't start
417 * arguing with it */
418 if (atomic_inc_return(&pool->item_count) <= pool->max_items)
419 break;
420
421 atomic_dec(&pool->item_count);
422
423 if (++iter > 2) {
424 rds_iw_stats_inc(s_iw_rdma_mr_pool_depleted);
425 return ERR_PTR(-EAGAIN);
426 }
427
428 /* We do have some empty MRs. Flush them out. */
429 rds_iw_stats_inc(s_iw_rdma_mr_pool_wait);
430 rds_iw_flush_mr_pool(pool, 0);
431 }
432
433 ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL);
434 if (!ibmr) {
435 err = -ENOMEM;
436 goto out_no_cigar;
437 }
438
439 spin_lock_init(&ibmr->mapping.m_lock);
440 INIT_LIST_HEAD(&ibmr->mapping.m_list);
441 ibmr->mapping.m_mr = ibmr;
442
443 err = rds_iw_init_fastreg(pool, ibmr);
444 if (err)
445 goto out_no_cigar;
446
447 rds_iw_stats_inc(s_iw_rdma_mr_alloc);
448 return ibmr;
449
450 out_no_cigar:
451 if (ibmr) {
452 rds_iw_destroy_fastreg(pool, ibmr);
453 kfree(ibmr);
454 }
455 atomic_dec(&pool->item_count);
456 return ERR_PTR(err);
457 }
458
459 void rds_iw_sync_mr(void *trans_private, int direction)
460 {
461 struct rds_iw_mr *ibmr = trans_private;
462 struct rds_iw_device *rds_iwdev = ibmr->device;
463
464 switch (direction) {
465 case DMA_FROM_DEVICE:
466 ib_dma_sync_sg_for_cpu(rds_iwdev->dev, ibmr->mapping.m_sg.list,
467 ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
468 break;
469 case DMA_TO_DEVICE:
470 ib_dma_sync_sg_for_device(rds_iwdev->dev, ibmr->mapping.m_sg.list,
471 ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL);
472 break;
473 }
474 }
475
476 /*
477 * Flush our pool of MRs.
478 * At a minimum, all currently unused MRs are unmapped.
479 * If the number of MRs allocated exceeds the limit, we also try
480 * to free as many MRs as needed to get back to this limit.
481 */
482 static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all)
483 {
484 struct rds_iw_mr *ibmr, *next;
485 LIST_HEAD(unmap_list);
486 LIST_HEAD(kill_list);
487 unsigned long flags;
488 unsigned int nfreed = 0, ncleaned = 0, unpinned = 0;
489 int ret = 0;
490
491 rds_iw_stats_inc(s_iw_rdma_mr_pool_flush);
492
493 mutex_lock(&pool->flush_lock);
494
495 spin_lock_irqsave(&pool->list_lock, flags);
496 /* Get the list of all mappings to be destroyed */
497 list_splice_init(&pool->dirty_list, &unmap_list);
498 if (free_all)
499 list_splice_init(&pool->clean_list, &kill_list);
500 spin_unlock_irqrestore(&pool->list_lock, flags);
501
502 /* Batched invalidate of dirty MRs.
503 * For FMR based MRs, the mappings on the unmap list are
504 * actually members of an ibmr (ibmr->mapping). They either
505 * migrate to the kill_list, or have been cleaned and should be
506 * moved to the clean_list.
507 * For fastregs, they will be dynamically allocated, and
508 * will be destroyed by the unmap function.
509 */
510 if (!list_empty(&unmap_list)) {
511 ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list,
512 &kill_list, &unpinned);
513 /* If we've been asked to destroy all MRs, move those
514 * that were simply cleaned to the kill list */
515 if (free_all)
516 list_splice_init(&unmap_list, &kill_list);
517 }
518
519 /* Destroy any MRs that are past their best before date */
520 list_for_each_entry_safe(ibmr, next, &kill_list, mapping.m_list) {
521 rds_iw_stats_inc(s_iw_rdma_mr_free);
522 list_del(&ibmr->mapping.m_list);
523 rds_iw_destroy_fastreg(pool, ibmr);
524 kfree(ibmr);
525 nfreed++;
526 }
527
528 /* Anything that remains are laundered ibmrs, which we can add
529 * back to the clean list. */
530 if (!list_empty(&unmap_list)) {
531 spin_lock_irqsave(&pool->list_lock, flags);
532 list_splice(&unmap_list, &pool->clean_list);
533 spin_unlock_irqrestore(&pool->list_lock, flags);
534 }
535
536 atomic_sub(unpinned, &pool->free_pinned);
537 atomic_sub(ncleaned, &pool->dirty_count);
538 atomic_sub(nfreed, &pool->item_count);
539
540 mutex_unlock(&pool->flush_lock);
541 return ret;
542 }
543
544 static void rds_iw_mr_pool_flush_worker(struct work_struct *work)
545 {
546 struct rds_iw_mr_pool *pool = container_of(work, struct rds_iw_mr_pool, flush_worker);
547
548 rds_iw_flush_mr_pool(pool, 0);
549 }
550
551 void rds_iw_free_mr(void *trans_private, int invalidate)
552 {
553 struct rds_iw_mr *ibmr = trans_private;
554 struct rds_iw_mr_pool *pool = ibmr->device->mr_pool;
555
556 rdsdebug("RDS/IW: free_mr nents %u\n", ibmr->mapping.m_sg.len);
557 if (!pool)
558 return;
559
560 /* Return it to the pool's free list */
561 rds_iw_free_fastreg(pool, ibmr);
562
563 /* If we've pinned too many pages, request a flush */
564 if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
565 atomic_read(&pool->dirty_count) >= pool->max_items / 10)
566 queue_work(rds_wq, &pool->flush_worker);
567
568 if (invalidate) {
569 if (likely(!in_interrupt())) {
570 rds_iw_flush_mr_pool(pool, 0);
571 } else {
572 /* We get here if the user created a MR marked
573 * as use_once and invalidate at the same time. */
574 queue_work(rds_wq, &pool->flush_worker);
575 }
576 }
577 }
578
579 void rds_iw_flush_mrs(void)
580 {
581 struct rds_iw_device *rds_iwdev;
582
583 list_for_each_entry(rds_iwdev, &rds_iw_devices, list) {
584 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool;
585
586 if (pool)
587 rds_iw_flush_mr_pool(pool, 0);
588 }
589 }
590
591 void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents,
592 struct rds_sock *rs, u32 *key_ret)
593 {
594 struct rds_iw_device *rds_iwdev;
595 struct rds_iw_mr *ibmr = NULL;
596 struct rdma_cm_id *cm_id;
597 struct sockaddr_in src = {
598 .sin_addr.s_addr = rs->rs_bound_addr,
599 .sin_port = rs->rs_bound_port,
600 };
601 struct sockaddr_in dst = {
602 .sin_addr.s_addr = rs->rs_conn_addr,
603 .sin_port = rs->rs_conn_port,
604 };
605 int ret;
606
607 ret = rds_iw_get_device(&src, &dst, &rds_iwdev, &cm_id);
608 if (ret || !cm_id) {
609 ret = -ENODEV;
610 goto out;
611 }
612
613 if (!rds_iwdev->mr_pool) {
614 ret = -ENODEV;
615 goto out;
616 }
617
618 ibmr = rds_iw_alloc_mr(rds_iwdev);
619 if (IS_ERR(ibmr))
620 return ibmr;
621
622 ibmr->cm_id = cm_id;
623 ibmr->device = rds_iwdev;
624
625 ret = rds_iw_map_fastreg(rds_iwdev->mr_pool, ibmr, sg, nents);
626 if (ret == 0)
627 *key_ret = ibmr->mr->rkey;
628 else
629 printk(KERN_WARNING "RDS/IW: failed to map mr (errno=%d)\n", ret);
630
631 out:
632 if (ret) {
633 if (ibmr)
634 rds_iw_free_mr(ibmr, 0);
635 ibmr = ERR_PTR(ret);
636 }
637 return ibmr;
638 }
639
640 /*
641 * iWARP fastreg handling
642 *
643 * The life cycle of a fastreg registration is a bit different from
644 * FMRs.
645 * The idea behind fastreg is to have one MR, to which we bind different
646 * mappings over time. To avoid stalling on the expensive map and invalidate
647 * operations, these operations are pipelined on the same send queue on
648 * which we want to send the message containing the r_key.
649 *
650 * This creates a bit of a problem for us, as we do not have the destination
651 * IP in GET_MR, so the connection must be setup prior to the GET_MR call for
652 * RDMA to be correctly setup. If a fastreg request is present, rds_iw_xmit
653 * will try to queue a LOCAL_INV (if needed) and a FAST_REG_MR work request
654 * before queuing the SEND. When completions for these arrive, they are
655 * dispatched to the MR has a bit set showing that RDMa can be performed.
656 *
657 * There is another interesting aspect that's related to invalidation.
658 * The application can request that a mapping is invalidated in FREE_MR.
659 * The expectation there is that this invalidation step includes ALL
660 * PREVIOUSLY FREED MRs.
661 */
662 static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool,
663 struct rds_iw_mr *ibmr)
664 {
665 struct rds_iw_device *rds_iwdev = pool->device;
666 struct ib_fast_reg_page_list *page_list = NULL;
667 struct ib_mr *mr;
668 int err;
669
670 mr = ib_alloc_fast_reg_mr(rds_iwdev->pd, pool->max_message_size);
671 if (IS_ERR(mr)) {
672 err = PTR_ERR(mr);
673
674 printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_mr failed (err=%d)\n", err);
675 return err;
676 }
677
678 /* FIXME - this is overkill, but mapping->m_sg.dma_len/mapping->m_sg.dma_npages
679 * is not filled in.
680 */
681 page_list = ib_alloc_fast_reg_page_list(rds_iwdev->dev, pool->max_message_size);
682 if (IS_ERR(page_list)) {
683 err = PTR_ERR(page_list);
684
685 printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_page_list failed (err=%d)\n", err);
686 ib_dereg_mr(mr);
687 return err;
688 }
689
690 ibmr->page_list = page_list;
691 ibmr->mr = mr;
692 return 0;
693 }
694
695 static int rds_iw_rdma_build_fastreg(struct rds_iw_mapping *mapping)
696 {
697 struct rds_iw_mr *ibmr = mapping->m_mr;
698 struct ib_send_wr f_wr, *failed_wr;
699 int ret;
700
701 /*
702 * Perform a WR for the fast_reg_mr. Each individual page
703 * in the sg list is added to the fast reg page list and placed
704 * inside the fast_reg_mr WR. The key used is a rolling 8bit
705 * counter, which should guarantee uniqueness.
706 */
707 ib_update_fast_reg_key(ibmr->mr, ibmr->remap_count++);
708 mapping->m_rkey = ibmr->mr->rkey;
709
710 memset(&f_wr, 0, sizeof(f_wr));
711 f_wr.wr_id = RDS_IW_FAST_REG_WR_ID;
712 f_wr.opcode = IB_WR_FAST_REG_MR;
713 f_wr.wr.fast_reg.length = mapping->m_sg.bytes;
714 f_wr.wr.fast_reg.rkey = mapping->m_rkey;
715 f_wr.wr.fast_reg.page_list = ibmr->page_list;
716 f_wr.wr.fast_reg.page_list_len = mapping->m_sg.dma_len;
717 f_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
718 f_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE |
719 IB_ACCESS_REMOTE_READ |
720 IB_ACCESS_REMOTE_WRITE;
721 f_wr.wr.fast_reg.iova_start = 0;
722 f_wr.send_flags = IB_SEND_SIGNALED;
723
724 failed_wr = &f_wr;
725 ret = ib_post_send(ibmr->cm_id->qp, &f_wr, &failed_wr);
726 BUG_ON(failed_wr != &f_wr);
727 if (ret)
728 printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
729 __func__, __LINE__, ret);
730 return ret;
731 }
732
733 static int rds_iw_rdma_fastreg_inv(struct rds_iw_mr *ibmr)
734 {
735 struct ib_send_wr s_wr, *failed_wr;
736 int ret = 0;
737
738 if (!ibmr->cm_id->qp || !ibmr->mr)
739 goto out;
740
741 memset(&s_wr, 0, sizeof(s_wr));
742 s_wr.wr_id = RDS_IW_LOCAL_INV_WR_ID;
743 s_wr.opcode = IB_WR_LOCAL_INV;
744 s_wr.ex.invalidate_rkey = ibmr->mr->rkey;
745 s_wr.send_flags = IB_SEND_SIGNALED;
746
747 failed_wr = &s_wr;
748 ret = ib_post_send(ibmr->cm_id->qp, &s_wr, &failed_wr);
749 if (ret) {
750 printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n",
751 __func__, __LINE__, ret);
752 goto out;
753 }
754 out:
755 return ret;
756 }
757
758 static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool,
759 struct rds_iw_mr *ibmr,
760 struct scatterlist *sg,
761 unsigned int sg_len)
762 {
763 struct rds_iw_device *rds_iwdev = pool->device;
764 struct rds_iw_mapping *mapping = &ibmr->mapping;
765 u64 *dma_pages;
766 int i, ret = 0;
767
768 rds_iw_set_scatterlist(&mapping->m_sg, sg, sg_len);
769
770 dma_pages = rds_iw_map_scatterlist(rds_iwdev, &mapping->m_sg);
771 if (IS_ERR(dma_pages)) {
772 ret = PTR_ERR(dma_pages);
773 dma_pages = NULL;
774 goto out;
775 }
776
777 if (mapping->m_sg.dma_len > pool->max_message_size) {
778 ret = -EMSGSIZE;
779 goto out;
780 }
781
782 for (i = 0; i < mapping->m_sg.dma_npages; ++i)
783 ibmr->page_list->page_list[i] = dma_pages[i];
784
785 ret = rds_iw_rdma_build_fastreg(mapping);
786 if (ret)
787 goto out;
788
789 rds_iw_stats_inc(s_iw_rdma_mr_used);
790
791 out:
792 kfree(dma_pages);
793
794 return ret;
795 }
796
797 /*
798 * "Free" a fastreg MR.
799 */
800 static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool,
801 struct rds_iw_mr *ibmr)
802 {
803 unsigned long flags;
804 int ret;
805
806 if (!ibmr->mapping.m_sg.dma_len)
807 return;
808
809 ret = rds_iw_rdma_fastreg_inv(ibmr);
810 if (ret)
811 return;
812
813 /* Try to post the LOCAL_INV WR to the queue. */
814 spin_lock_irqsave(&pool->list_lock, flags);
815
816 list_add_tail(&ibmr->mapping.m_list, &pool->dirty_list);
817 atomic_add(ibmr->mapping.m_sg.len, &pool->free_pinned);
818 atomic_inc(&pool->dirty_count);
819
820 spin_unlock_irqrestore(&pool->list_lock, flags);
821 }
822
823 static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,
824 struct list_head *unmap_list,
825 struct list_head *kill_list,
826 int *unpinned)
827 {
828 struct rds_iw_mapping *mapping, *next;
829 unsigned int ncleaned = 0;
830 LIST_HEAD(laundered);
831
832 /* Batched invalidation of fastreg MRs.
833 * Why do we do it this way, even though we could pipeline unmap
834 * and remap? The reason is the application semantics - when the
835 * application requests an invalidation of MRs, it expects all
836 * previously released R_Keys to become invalid.
837 *
838 * If we implement MR reuse naively, we risk memory corruption
839 * (this has actually been observed). So the default behavior
840 * requires that a MR goes through an explicit unmap operation before
841 * we can reuse it again.
842 *
843 * We could probably improve on this a little, by allowing immediate
844 * reuse of a MR on the same socket (eg you could add small
845 * cache of unused MRs to strct rds_socket - GET_MR could grab one
846 * of these without requiring an explicit invalidate).
847 */
848 while (!list_empty(unmap_list)) {
849 unsigned long flags;
850
851 spin_lock_irqsave(&pool->list_lock, flags);
852 list_for_each_entry_safe(mapping, next, unmap_list, m_list) {
853 *unpinned += mapping->m_sg.len;
854 list_move(&mapping->m_list, &laundered);
855 ncleaned++;
856 }
857 spin_unlock_irqrestore(&pool->list_lock, flags);
858 }
859
860 /* Move all laundered mappings back to the unmap list.
861 * We do not kill any WRs right now - it doesn't seem the
862 * fastreg API has a max_remap limit. */
863 list_splice_init(&laundered, unmap_list);
864
865 return ncleaned;
866 }
867
868 static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool,
869 struct rds_iw_mr *ibmr)
870 {
871 if (ibmr->page_list)
872 ib_free_fast_reg_page_list(ibmr->page_list);
873 if (ibmr->mr)
874 ib_dereg_mr(ibmr->mr);
875 }
876