blob: 4c64daa1f5d52b0eb72b6920bd7f4a39a3a756b9 [file] [log] [blame]
Andy Grovereff5f532009-02-24 15:30:29 +00001/*
2 * Copyright (c) 2007 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/pagemap.h>
34#include <linux/rbtree.h>
35#include <linux/dma-mapping.h> /* for DMA_*_DEVICE */
36
37#include "rdma.h"
38
39/*
40 * XXX
41 * - build with sparse
42 * - should we limit the size of a mr region? let transport return failure?
43 * - should we detect duplicate keys on a socket? hmm.
44 * - an rdma is an mlock, apply rlimit?
45 */
46
47/*
48 * get the number of pages by looking at the page indices that the start and
49 * end addresses fall in.
50 *
51 * Returns 0 if the vec is invalid. It is invalid if the number of bytes
52 * causes the address to wrap or overflows an unsigned int. This comes
53 * from being stored in the 'length' member of 'struct scatterlist'.
54 */
55static unsigned int rds_pages_in_vec(struct rds_iovec *vec)
56{
57 if ((vec->addr + vec->bytes <= vec->addr) ||
58 (vec->bytes > (u64)UINT_MAX))
59 return 0;
60
61 return ((vec->addr + vec->bytes + PAGE_SIZE - 1) >> PAGE_SHIFT) -
62 (vec->addr >> PAGE_SHIFT);
63}
64
65static struct rds_mr *rds_mr_tree_walk(struct rb_root *root, u64 key,
66 struct rds_mr *insert)
67{
68 struct rb_node **p = &root->rb_node;
69 struct rb_node *parent = NULL;
70 struct rds_mr *mr;
71
72 while (*p) {
73 parent = *p;
74 mr = rb_entry(parent, struct rds_mr, r_rb_node);
75
76 if (key < mr->r_key)
77 p = &(*p)->rb_left;
78 else if (key > mr->r_key)
79 p = &(*p)->rb_right;
80 else
81 return mr;
82 }
83
84 if (insert) {
85 rb_link_node(&insert->r_rb_node, parent, p);
86 rb_insert_color(&insert->r_rb_node, root);
87 atomic_inc(&insert->r_refcount);
88 }
89 return NULL;
90}
91
92/*
93 * Destroy the transport-specific part of a MR.
94 */
95static void rds_destroy_mr(struct rds_mr *mr)
96{
97 struct rds_sock *rs = mr->r_sock;
98 void *trans_private = NULL;
99 unsigned long flags;
100
101 rdsdebug("RDS: destroy mr key is %x refcnt %u\n",
102 mr->r_key, atomic_read(&mr->r_refcount));
103
104 if (test_and_set_bit(RDS_MR_DEAD, &mr->r_state))
105 return;
106
107 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
108 if (!RB_EMPTY_NODE(&mr->r_rb_node))
109 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
110 trans_private = mr->r_trans_private;
111 mr->r_trans_private = NULL;
112 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
113
114 if (trans_private)
115 mr->r_trans->free_mr(trans_private, mr->r_invalidate);
116}
117
118void __rds_put_mr_final(struct rds_mr *mr)
119{
120 rds_destroy_mr(mr);
121 kfree(mr);
122}
123
124/*
125 * By the time this is called we can't have any more ioctls called on
126 * the socket so we don't need to worry about racing with others.
127 */
128void rds_rdma_drop_keys(struct rds_sock *rs)
129{
130 struct rds_mr *mr;
131 struct rb_node *node;
132
133 /* Release any MRs associated with this socket */
134 while ((node = rb_first(&rs->rs_rdma_keys))) {
135 mr = container_of(node, struct rds_mr, r_rb_node);
136 if (mr->r_trans == rs->rs_transport)
137 mr->r_invalidate = 0;
138 rds_mr_put(mr);
139 }
140
141 if (rs->rs_transport && rs->rs_transport->flush_mrs)
142 rs->rs_transport->flush_mrs();
143}
144
145/*
146 * Helper function to pin user pages.
147 */
148static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages,
149 struct page **pages, int write)
150{
151 int ret;
152
Andy Grover830eb7d2009-04-09 14:09:42 +0000153 ret = get_user_pages_fast(user_addr, nr_pages, write, pages);
Andy Grovereff5f532009-02-24 15:30:29 +0000154
Andy Grover7acd4a72009-04-09 14:09:40 +0000155 if (ret >= 0 && ret < nr_pages) {
Andy Grovereff5f532009-02-24 15:30:29 +0000156 while (ret--)
157 put_page(pages[ret]);
158 ret = -EFAULT;
159 }
160
161 return ret;
162}
163
164static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
165 u64 *cookie_ret, struct rds_mr **mr_ret)
166{
167 struct rds_mr *mr = NULL, *found;
168 unsigned int nr_pages;
169 struct page **pages = NULL;
170 struct scatterlist *sg;
171 void *trans_private;
172 unsigned long flags;
173 rds_rdma_cookie_t cookie;
174 unsigned int nents;
175 long i;
176 int ret;
177
178 if (rs->rs_bound_addr == 0) {
179 ret = -ENOTCONN; /* XXX not a great errno */
180 goto out;
181 }
182
183 if (rs->rs_transport->get_mr == NULL) {
184 ret = -EOPNOTSUPP;
185 goto out;
186 }
187
188 nr_pages = rds_pages_in_vec(&args->vec);
189 if (nr_pages == 0) {
190 ret = -EINVAL;
191 goto out;
192 }
193
194 rdsdebug("RDS: get_mr addr %llx len %llu nr_pages %u\n",
195 args->vec.addr, args->vec.bytes, nr_pages);
196
197 /* XXX clamp nr_pages to limit the size of this alloc? */
198 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
199 if (pages == NULL) {
200 ret = -ENOMEM;
201 goto out;
202 }
203
204 mr = kzalloc(sizeof(struct rds_mr), GFP_KERNEL);
205 if (mr == NULL) {
206 ret = -ENOMEM;
207 goto out;
208 }
209
210 atomic_set(&mr->r_refcount, 1);
211 RB_CLEAR_NODE(&mr->r_rb_node);
212 mr->r_trans = rs->rs_transport;
213 mr->r_sock = rs;
214
215 if (args->flags & RDS_RDMA_USE_ONCE)
216 mr->r_use_once = 1;
217 if (args->flags & RDS_RDMA_INVALIDATE)
218 mr->r_invalidate = 1;
219 if (args->flags & RDS_RDMA_READWRITE)
220 mr->r_write = 1;
221
222 /*
223 * Pin the pages that make up the user buffer and transfer the page
224 * pointers to the mr's sg array. We check to see if we've mapped
225 * the whole region after transferring the partial page references
226 * to the sg array so that we can have one page ref cleanup path.
227 *
228 * For now we have no flag that tells us whether the mapping is
229 * r/o or r/w. We need to assume r/w, or we'll do a lot of RDMA to
230 * the zero page.
231 */
232 ret = rds_pin_pages(args->vec.addr & PAGE_MASK, nr_pages, pages, 1);
233 if (ret < 0)
234 goto out;
235
236 nents = ret;
237 sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL);
238 if (sg == NULL) {
239 ret = -ENOMEM;
240 goto out;
241 }
242 WARN_ON(!nents);
243 sg_init_table(sg, nents);
244
245 /* Stick all pages into the scatterlist */
246 for (i = 0 ; i < nents; i++)
247 sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0);
248
249 rdsdebug("RDS: trans_private nents is %u\n", nents);
250
251 /* Obtain a transport specific MR. If this succeeds, the
252 * s/g list is now owned by the MR.
253 * Note that dma_map() implies that pending writes are
254 * flushed to RAM, so no dma_sync is needed here. */
255 trans_private = rs->rs_transport->get_mr(sg, nents, rs,
256 &mr->r_key);
257
258 if (IS_ERR(trans_private)) {
259 for (i = 0 ; i < nents; i++)
260 put_page(sg_page(&sg[i]));
261 kfree(sg);
262 ret = PTR_ERR(trans_private);
263 goto out;
264 }
265
266 mr->r_trans_private = trans_private;
267
268 rdsdebug("RDS: get_mr put_user key is %x cookie_addr %p\n",
269 mr->r_key, (void *)(unsigned long) args->cookie_addr);
270
271 /* The user may pass us an unaligned address, but we can only
272 * map page aligned regions. So we keep the offset, and build
273 * a 64bit cookie containing <R_Key, offset> and pass that
274 * around. */
275 cookie = rds_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGE_MASK);
276 if (cookie_ret)
277 *cookie_ret = cookie;
278
279 if (args->cookie_addr && put_user(cookie, (u64 __user *)(unsigned long) args->cookie_addr)) {
280 ret = -EFAULT;
281 goto out;
282 }
283
284 /* Inserting the new MR into the rbtree bumps its
285 * reference count. */
286 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
287 found = rds_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
288 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
289
290 BUG_ON(found && found != mr);
291
292 rdsdebug("RDS: get_mr key is %x\n", mr->r_key);
293 if (mr_ret) {
294 atomic_inc(&mr->r_refcount);
295 *mr_ret = mr;
296 }
297
298 ret = 0;
299out:
300 kfree(pages);
301 if (mr)
302 rds_mr_put(mr);
303 return ret;
304}
305
306int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen)
307{
308 struct rds_get_mr_args args;
309
310 if (optlen != sizeof(struct rds_get_mr_args))
311 return -EINVAL;
312
313 if (copy_from_user(&args, (struct rds_get_mr_args __user *)optval,
314 sizeof(struct rds_get_mr_args)))
315 return -EFAULT;
316
317 return __rds_rdma_map(rs, &args, NULL, NULL);
318}
319
Andy Grover244546f2009-10-30 08:54:53 +0000320int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen)
321{
322 struct rds_get_mr_for_dest_args args;
323 struct rds_get_mr_args new_args;
324
325 if (optlen != sizeof(struct rds_get_mr_for_dest_args))
326 return -EINVAL;
327
328 if (copy_from_user(&args, (struct rds_get_mr_for_dest_args __user *)optval,
329 sizeof(struct rds_get_mr_for_dest_args)))
330 return -EFAULT;
331
332 /*
333 * Initially, just behave like get_mr().
334 * TODO: Implement get_mr as wrapper around this
335 * and deprecate it.
336 */
337 new_args.vec = args.vec;
338 new_args.cookie_addr = args.cookie_addr;
339 new_args.flags = args.flags;
340
341 return __rds_rdma_map(rs, &new_args, NULL, NULL);
342}
343
Andy Grovereff5f532009-02-24 15:30:29 +0000344/*
345 * Free the MR indicated by the given R_Key
346 */
347int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen)
348{
349 struct rds_free_mr_args args;
350 struct rds_mr *mr;
351 unsigned long flags;
352
353 if (optlen != sizeof(struct rds_free_mr_args))
354 return -EINVAL;
355
356 if (copy_from_user(&args, (struct rds_free_mr_args __user *)optval,
357 sizeof(struct rds_free_mr_args)))
358 return -EFAULT;
359
360 /* Special case - a null cookie means flush all unused MRs */
361 if (args.cookie == 0) {
362 if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
363 return -EINVAL;
364 rs->rs_transport->flush_mrs();
365 return 0;
366 }
367
368 /* Look up the MR given its R_key and remove it from the rbtree
369 * so nobody else finds it.
370 * This should also prevent races with rds_rdma_unuse.
371 */
372 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
373 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, rds_rdma_cookie_key(args.cookie), NULL);
374 if (mr) {
375 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
376 RB_CLEAR_NODE(&mr->r_rb_node);
377 if (args.flags & RDS_RDMA_INVALIDATE)
378 mr->r_invalidate = 1;
379 }
380 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
381
382 if (!mr)
383 return -EINVAL;
384
385 /*
386 * call rds_destroy_mr() ourselves so that we're sure it's done by the time
387 * we return. If we let rds_mr_put() do it it might not happen until
388 * someone else drops their ref.
389 */
390 rds_destroy_mr(mr);
391 rds_mr_put(mr);
392 return 0;
393}
394
395/*
396 * This is called when we receive an extension header that
397 * tells us this MR was used. It allows us to implement
398 * use_once semantics
399 */
400void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force)
401{
402 struct rds_mr *mr;
403 unsigned long flags;
404 int zot_me = 0;
405
406 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
407 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
408 if (mr && (mr->r_use_once || force)) {
409 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
410 RB_CLEAR_NODE(&mr->r_rb_node);
411 zot_me = 1;
412 } else if (mr)
413 atomic_inc(&mr->r_refcount);
414 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
415
416 /* May have to issue a dma_sync on this memory region.
417 * Note we could avoid this if the operation was a RDMA READ,
418 * but at this point we can't tell. */
419 if (mr != NULL) {
420 if (mr->r_trans->sync_mr)
421 mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
422
423 /* If the MR was marked as invalidate, this will
424 * trigger an async flush. */
425 if (zot_me)
426 rds_destroy_mr(mr);
427 rds_mr_put(mr);
428 }
429}
430
431void rds_rdma_free_op(struct rds_rdma_op *ro)
432{
433 unsigned int i;
434
435 for (i = 0; i < ro->r_nents; i++) {
436 struct page *page = sg_page(&ro->r_sg[i]);
437
438 /* Mark page dirty if it was possibly modified, which
439 * is the case for a RDMA_READ which copies from remote
440 * to local memory */
441 if (!ro->r_write)
442 set_page_dirty(page);
443 put_page(page);
444 }
445
446 kfree(ro->r_notifier);
447 kfree(ro);
448}
449
450/*
451 * args is a pointer to an in-kernel copy in the sendmsg cmsg.
452 */
453static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,
454 struct rds_rdma_args *args)
455{
456 struct rds_iovec vec;
457 struct rds_rdma_op *op = NULL;
458 unsigned int nr_pages;
459 unsigned int max_pages;
460 unsigned int nr_bytes;
461 struct page **pages = NULL;
462 struct rds_iovec __user *local_vec;
463 struct scatterlist *sg;
464 unsigned int nr;
465 unsigned int i, j;
466 int ret;
467
468
469 if (rs->rs_bound_addr == 0) {
470 ret = -ENOTCONN; /* XXX not a great errno */
471 goto out;
472 }
473
474 if (args->nr_local > (u64)UINT_MAX) {
475 ret = -EMSGSIZE;
476 goto out;
477 }
478
479 nr_pages = 0;
480 max_pages = 0;
481
482 local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
483
484 /* figure out the number of pages in the vector */
485 for (i = 0; i < args->nr_local; i++) {
486 if (copy_from_user(&vec, &local_vec[i],
487 sizeof(struct rds_iovec))) {
488 ret = -EFAULT;
489 goto out;
490 }
491
492 nr = rds_pages_in_vec(&vec);
493 if (nr == 0) {
494 ret = -EINVAL;
495 goto out;
496 }
497
498 max_pages = max(nr, max_pages);
499 nr_pages += nr;
500 }
501
502 pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL);
503 if (pages == NULL) {
504 ret = -ENOMEM;
505 goto out;
506 }
507
508 op = kzalloc(offsetof(struct rds_rdma_op, r_sg[nr_pages]), GFP_KERNEL);
509 if (op == NULL) {
510 ret = -ENOMEM;
511 goto out;
512 }
513
514 op->r_write = !!(args->flags & RDS_RDMA_READWRITE);
515 op->r_fence = !!(args->flags & RDS_RDMA_FENCE);
516 op->r_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
517 op->r_recverr = rs->rs_recverr;
518 WARN_ON(!nr_pages);
519 sg_init_table(op->r_sg, nr_pages);
520
521 if (op->r_notify || op->r_recverr) {
522 /* We allocate an uninitialized notifier here, because
523 * we don't want to do that in the completion handler. We
524 * would have to use GFP_ATOMIC there, and don't want to deal
525 * with failed allocations.
526 */
527 op->r_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL);
528 if (!op->r_notifier) {
529 ret = -ENOMEM;
530 goto out;
531 }
532 op->r_notifier->n_user_token = args->user_token;
533 op->r_notifier->n_status = RDS_RDMA_SUCCESS;
534 }
535
536 /* The cookie contains the R_Key of the remote memory region, and
537 * optionally an offset into it. This is how we implement RDMA into
538 * unaligned memory.
539 * When setting up the RDMA, we need to add that offset to the
540 * destination address (which is really an offset into the MR)
541 * FIXME: We may want to move this into ib_rdma.c
542 */
543 op->r_key = rds_rdma_cookie_key(args->cookie);
544 op->r_remote_addr = args->remote_vec.addr + rds_rdma_cookie_offset(args->cookie);
545
546 nr_bytes = 0;
547
548 rdsdebug("RDS: rdma prepare nr_local %llu rva %llx rkey %x\n",
549 (unsigned long long)args->nr_local,
550 (unsigned long long)args->remote_vec.addr,
551 op->r_key);
552
553 for (i = 0; i < args->nr_local; i++) {
554 if (copy_from_user(&vec, &local_vec[i],
555 sizeof(struct rds_iovec))) {
556 ret = -EFAULT;
557 goto out;
558 }
559
560 nr = rds_pages_in_vec(&vec);
561 if (nr == 0) {
562 ret = -EINVAL;
563 goto out;
564 }
565
566 rs->rs_user_addr = vec.addr;
567 rs->rs_user_bytes = vec.bytes;
568
569 /* did the user change the vec under us? */
570 if (nr > max_pages || op->r_nents + nr > nr_pages) {
571 ret = -EINVAL;
572 goto out;
573 }
574 /* If it's a WRITE operation, we want to pin the pages for reading.
575 * If it's a READ operation, we need to pin the pages for writing.
576 */
577 ret = rds_pin_pages(vec.addr & PAGE_MASK, nr, pages, !op->r_write);
578 if (ret < 0)
579 goto out;
580
581 rdsdebug("RDS: nr_bytes %u nr %u vec.bytes %llu vec.addr %llx\n",
582 nr_bytes, nr, vec.bytes, vec.addr);
583
584 nr_bytes += vec.bytes;
585
586 for (j = 0; j < nr; j++) {
587 unsigned int offset = vec.addr & ~PAGE_MASK;
588
589 sg = &op->r_sg[op->r_nents + j];
590 sg_set_page(sg, pages[j],
591 min_t(unsigned int, vec.bytes, PAGE_SIZE - offset),
592 offset);
593
594 rdsdebug("RDS: sg->offset %x sg->len %x vec.addr %llx vec.bytes %llu\n",
595 sg->offset, sg->length, vec.addr, vec.bytes);
596
597 vec.addr += sg->length;
598 vec.bytes -= sg->length;
599 }
600
601 op->r_nents += nr;
602 }
603
604
605 if (nr_bytes > args->remote_vec.bytes) {
606 rdsdebug("RDS nr_bytes %u remote_bytes %u do not match\n",
607 nr_bytes,
608 (unsigned int) args->remote_vec.bytes);
609 ret = -EINVAL;
610 goto out;
611 }
612 op->r_bytes = nr_bytes;
613
614 ret = 0;
615out:
616 kfree(pages);
617 if (ret) {
618 if (op)
619 rds_rdma_free_op(op);
620 op = ERR_PTR(ret);
621 }
622 return op;
623}
624
625/*
626 * The application asks for a RDMA transfer.
627 * Extract all arguments and set up the rdma_op
628 */
629int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
630 struct cmsghdr *cmsg)
631{
632 struct rds_rdma_op *op;
633
Joe Perchesf64f9e72009-11-29 16:55:45 -0800634 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args)) ||
635 rm->m_rdma_op != NULL)
Andy Grovereff5f532009-02-24 15:30:29 +0000636 return -EINVAL;
637
638 op = rds_rdma_prepare(rs, CMSG_DATA(cmsg));
639 if (IS_ERR(op))
640 return PTR_ERR(op);
641 rds_stats_inc(s_send_rdma);
642 rm->m_rdma_op = op;
643 return 0;
644}
645
646/*
647 * The application wants us to pass an RDMA destination (aka MR)
648 * to the remote
649 */
650int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
651 struct cmsghdr *cmsg)
652{
653 unsigned long flags;
654 struct rds_mr *mr;
655 u32 r_key;
656 int err = 0;
657
Joe Perchesf64f9e72009-11-29 16:55:45 -0800658 if (cmsg->cmsg_len < CMSG_LEN(sizeof(rds_rdma_cookie_t)) ||
659 rm->m_rdma_cookie != 0)
Andy Grovereff5f532009-02-24 15:30:29 +0000660 return -EINVAL;
661
662 memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg), sizeof(rm->m_rdma_cookie));
663
664 /* We are reusing a previously mapped MR here. Most likely, the
665 * application has written to the buffer, so we need to explicitly
666 * flush those writes to RAM. Otherwise the HCA may not see them
667 * when doing a DMA from that buffer.
668 */
669 r_key = rds_rdma_cookie_key(rm->m_rdma_cookie);
670
671 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
672 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
673 if (mr == NULL)
674 err = -EINVAL; /* invalid r_key */
675 else
676 atomic_inc(&mr->r_refcount);
677 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
678
679 if (mr) {
680 mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
681 rm->m_rdma_mr = mr;
682 }
683 return err;
684}
685
686/*
687 * The application passes us an address range it wants to enable RDMA
688 * to/from. We map the area, and save the <R_Key,offset> pair
689 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
690 * in an extension header.
691 */
692int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
693 struct cmsghdr *cmsg)
694{
Joe Perchesf64f9e72009-11-29 16:55:45 -0800695 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_get_mr_args)) ||
696 rm->m_rdma_cookie != 0)
Andy Grovereff5f532009-02-24 15:30:29 +0000697 return -EINVAL;
698
699 return __rds_rdma_map(rs, CMSG_DATA(cmsg), &rm->m_rdma_cookie, &rm->m_rdma_mr);
700}