1 /*
2 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
3 */
4
5 /*
6 * This file contains code imported from the OFED rds source file rdma.c
7 * Oracle elects to have and use the contents of rdma.c under and governed
8 * by the OpenIB.org BSD license (see below for full license text). However,
9 * the following notice accompanied the original version of this file:
10 */
11
12 /*
13 * Copyright (c) 2007 Oracle. All rights reserved.
14 *
15 * This software is available to you under a choice of one of two
16 * licenses. You may choose to be licensed under the terms of the GNU
17 * General Public License (GPL) Version 2, available from the file
18 * COPYING in the main directory of this source tree, or the
19 * OpenIB.org BSD license below:
20 *
21 * Redistribution and use in source and binary forms, with or
22 * without modification, are permitted provided that the following
23 * conditions are met:
24 *
25 * - Redistributions of source code must retain the above
26 * copyright notice, this list of conditions and the following
27 * disclaimer.
28 *
29 * - Redistributions in binary form must reproduce the above
30 * copyright notice, this list of conditions and the following
31 * disclaimer in the documentation and/or other materials
32 * provided with the distribution.
33 *
34 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
35 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
36 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
37 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
38 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
39 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
40 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
41 * SOFTWARE.
42 *
43 */
44 #include <sys/ib/clients/of/rdma/ib_verbs.h>
45 #include <sys/ib/clients/of/rdma/ib_addr.h>
46 #include <sys/ib/clients/of/rdma/rdma_cm.h>
47
48 #include <sys/ib/clients/rdsv3/ib.h>
49 #include <sys/ib/clients/rdsv3/rdma.h>
50 #include <sys/ib/clients/rdsv3/rdsv3_debug.h>
51
52 #define DMA_TO_DEVICE 0
53 #define DMA_FROM_DEVICE 1
54 #define RB_CLEAR_NODE(nodep) AVL_SETPARENT(nodep, nodep);
55
56 /*
57 * XXX
58 * - build with sparse
59 * - should we limit the size of a mr region? let transport return failure?
60 * - should we detect duplicate keys on a socket? hmm.
61 * - an rdma is an mlock, apply rlimit?
62 */
63
64 /*
65 * get the number of pages by looking at the page indices that the start and
66 * end addresses fall in.
67 *
68 * Returns 0 if the vec is invalid. It is invalid if the number of bytes
69 * causes the address to wrap or overflows an unsigned int. This comes
70 * from being stored in the 'length' member of 'struct rdsv3_scatterlist'.
71 */
72 static unsigned int
rdsv3_pages_in_vec(struct rds_iovec * vec)73 rdsv3_pages_in_vec(struct rds_iovec *vec)
74 {
75 if ((vec->addr + vec->bytes <= vec->addr) ||
76 (vec->bytes > (uint64_t)UINT_MAX)) {
77 return (0);
78 }
79
80 return (((vec->addr + vec->bytes + PAGESIZE - 1) >>
81 PAGESHIFT) - (vec->addr >> PAGESHIFT));
82 }
83
84 static struct rdsv3_mr *
rdsv3_mr_tree_walk(struct avl_tree * root,uint32_t key,struct rdsv3_mr * insert)85 rdsv3_mr_tree_walk(struct avl_tree *root, uint32_t key,
86 struct rdsv3_mr *insert)
87 {
88 struct rdsv3_mr *mr;
89 avl_index_t where;
90
91 mr = avl_find(root, &key, &where);
92 if ((mr == NULL) && (insert != NULL)) {
93 avl_insert(root, (void *)insert, where);
94 atomic_inc_32(&insert->r_refcount);
95 return (NULL);
96 }
97
98 return (mr);
99 }
100
101 /*
102 * Destroy the transport-specific part of a MR.
103 */
104 static void
rdsv3_destroy_mr(struct rdsv3_mr * mr)105 rdsv3_destroy_mr(struct rdsv3_mr *mr)
106 {
107 struct rdsv3_sock *rs = mr->r_sock;
108 void *trans_private = NULL;
109 avl_node_t *np;
110
111 RDSV3_DPRINTF5("rdsv3_destroy_mr",
112 "RDS: destroy mr key is %x refcnt %u",
113 mr->r_key, atomic_get(&mr->r_refcount));
114
115 if (test_and_set_bit(RDSV3_MR_DEAD, &mr->r_state))
116 return;
117
118 mutex_enter(&rs->rs_rdma_lock);
119 np = &mr->r_rb_node;
120 if (AVL_XPARENT(np) != np)
121 avl_remove(&rs->rs_rdma_keys, mr);
122 trans_private = mr->r_trans_private;
123 mr->r_trans_private = NULL;
124 mutex_exit(&rs->rs_rdma_lock);
125
126 if (trans_private)
127 mr->r_trans->free_mr(trans_private, mr->r_invalidate);
128 }
129
130 void
__rdsv3_put_mr_final(struct rdsv3_mr * mr)131 __rdsv3_put_mr_final(struct rdsv3_mr *mr)
132 {
133 rdsv3_destroy_mr(mr);
134 kmem_free(mr, sizeof (*mr));
135 }
136
137 /*
138 * By the time this is called we can't have any more ioctls called on
139 * the socket so we don't need to worry about racing with others.
140 */
141 void
rdsv3_rdma_drop_keys(struct rdsv3_sock * rs)142 rdsv3_rdma_drop_keys(struct rdsv3_sock *rs)
143 {
144 struct rdsv3_mr *mr;
145 struct avl_node *node;
146
147 /* Release any MRs associated with this socket */
148 mutex_enter(&rs->rs_rdma_lock);
149 while ((node = avl_first(&rs->rs_rdma_keys))) {
150 mr = container_of(node, struct rdsv3_mr, r_rb_node);
151 if (mr->r_trans == rs->rs_transport)
152 mr->r_invalidate = 0;
153 avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
154 RB_CLEAR_NODE(&mr->r_rb_node)
155 mutex_exit(&rs->rs_rdma_lock);
156 rdsv3_destroy_mr(mr);
157 rdsv3_mr_put(mr);
158 mutex_enter(&rs->rs_rdma_lock);
159 }
160 mutex_exit(&rs->rs_rdma_lock);
161
162 if (rs->rs_transport && rs->rs_transport->flush_mrs)
163 rs->rs_transport->flush_mrs();
164 }
165
166 static int
__rdsv3_rdma_map(struct rdsv3_sock * rs,struct rds_get_mr_args * args,uint64_t * cookie_ret,struct rdsv3_mr ** mr_ret)167 __rdsv3_rdma_map(struct rdsv3_sock *rs, struct rds_get_mr_args *args,
168 uint64_t *cookie_ret, struct rdsv3_mr **mr_ret)
169 {
170 struct rdsv3_mr *mr = NULL, *found;
171 void *trans_private;
172 rds_rdma_cookie_t cookie;
173 unsigned int nents = 0;
174 int ret;
175
176 if (rs->rs_bound_addr == 0) {
177 ret = -ENOTCONN; /* XXX not a great errno */
178 goto out;
179 }
180
181 if (!rs->rs_transport->get_mr) {
182 ret = -EOPNOTSUPP;
183 goto out;
184 }
185
186 mr = kmem_zalloc(sizeof (struct rdsv3_mr), KM_NOSLEEP);
187 if (!mr) {
188 ret = -ENOMEM;
189 goto out;
190 }
191
192 mr->r_refcount = 1;
193 RB_CLEAR_NODE(&mr->r_rb_node);
194 mr->r_trans = rs->rs_transport;
195 mr->r_sock = rs;
196
197 if (args->flags & RDS_RDMA_USE_ONCE)
198 mr->r_use_once = 1;
199 if (args->flags & RDS_RDMA_INVALIDATE)
200 mr->r_invalidate = 1;
201 if (args->flags & RDS_RDMA_READWRITE)
202 mr->r_write = 1;
203
204 /*
205 * Obtain a transport specific MR. If this succeeds, the
206 * s/g list is now owned by the MR.
207 * Note that dma_map() implies that pending writes are
208 * flushed to RAM, so no dma_sync is needed here.
209 */
210 trans_private = rs->rs_transport->get_mr(&args->vec, nents, rs,
211 &mr->r_key);
212
213 if (IS_ERR(trans_private)) {
214 ret = PTR_ERR(trans_private);
215 goto out;
216 }
217
218 mr->r_trans_private = trans_private;
219
220 /*
221 * The user may pass us an unaligned address, but we can only
222 * map page aligned regions. So we keep the offset, and build
223 * a 64bit cookie containing <R_Key, offset> and pass that
224 * around.
225 */
226 cookie = rdsv3_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGEMASK);
227 if (cookie_ret)
228 *cookie_ret = cookie;
229
230 /*
231 * copy value of cookie to user address at args->cookie_addr
232 */
233 if (args->cookie_addr) {
234 ret = ddi_copyout((void *)&cookie,
235 (void *)((intptr_t)args->cookie_addr),
236 sizeof (rds_rdma_cookie_t), 0);
237 if (ret != 0) {
238 ret = -EFAULT;
239 goto out;
240 }
241 }
242
243 RDSV3_DPRINTF5("__rdsv3_rdma_map",
244 "RDS: get_mr mr 0x%p addr 0x%llx key 0x%x",
245 mr, args->vec.addr, mr->r_key);
246 /*
247 * Inserting the new MR into the rbtree bumps its
248 * reference count.
249 */
250 mutex_enter(&rs->rs_rdma_lock);
251 found = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
252 mutex_exit(&rs->rs_rdma_lock);
253
254 ASSERT(!(found && found != mr));
255
256 if (mr_ret) {
257 atomic_inc_32(&mr->r_refcount);
258 *mr_ret = mr;
259 }
260
261 ret = 0;
262 out:
263 if (mr)
264 rdsv3_mr_put(mr);
265 return (ret);
266 }
267
268 int
rdsv3_get_mr(struct rdsv3_sock * rs,const void * optval,int optlen)269 rdsv3_get_mr(struct rdsv3_sock *rs, const void *optval, int optlen)
270 {
271 struct rds_get_mr_args args;
272
273 if (optlen != sizeof (struct rds_get_mr_args))
274 return (-EINVAL);
275
276 #if 1
277 bcopy((struct rds_get_mr_args *)optval, &args,
278 sizeof (struct rds_get_mr_args));
279 #else
280 if (ddi_copyin(optval, &args, optlen, 0))
281 return (-EFAULT);
282 #endif
283
284 return (__rdsv3_rdma_map(rs, &args, NULL, NULL));
285 }
286
287 int
rdsv3_get_mr_for_dest(struct rdsv3_sock * rs,const void * optval,int optlen)288 rdsv3_get_mr_for_dest(struct rdsv3_sock *rs, const void *optval,
289 int optlen)
290 {
291 struct rds_get_mr_for_dest_args args;
292 struct rds_get_mr_args new_args;
293
294 if (optlen != sizeof (struct rds_get_mr_for_dest_args))
295 return (-EINVAL);
296
297 #if 1
298 bcopy((struct rds_get_mr_for_dest_args *)optval, &args,
299 sizeof (struct rds_get_mr_for_dest_args));
300 #else
301 if (ddi_copyin(optval, &args, optlen, 0))
302 return (-EFAULT);
303 #endif
304
305 /*
306 * Initially, just behave like get_mr().
307 * TODO: Implement get_mr as wrapper around this
308 * and deprecate it.
309 */
310 new_args.vec = args.vec;
311 new_args.cookie_addr = args.cookie_addr;
312 new_args.flags = args.flags;
313
314 return (__rdsv3_rdma_map(rs, &new_args, NULL, NULL));
315 }
316
317 /*
318 * Free the MR indicated by the given R_Key
319 */
320 int
rdsv3_free_mr(struct rdsv3_sock * rs,const void * optval,int optlen)321 rdsv3_free_mr(struct rdsv3_sock *rs, const void *optval, int optlen)
322 {
323 struct rds_free_mr_args args;
324 struct rdsv3_mr *mr;
325
326 if (optlen != sizeof (struct rds_free_mr_args))
327 return (-EINVAL);
328
329 #if 1
330 bcopy((struct rds_free_mr_args *)optval, &args,
331 sizeof (struct rds_free_mr_args));
332 #else
333 if (ddi_copyin((struct rds_free_mr_args *)optval, &args,
334 sizeof (struct rds_free_mr_args), 0))
335 return (-EFAULT);
336 #endif
337
338 /* Special case - a null cookie means flush all unused MRs */
339 if (args.cookie == 0) {
340 if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
341 return (-EINVAL);
342 rs->rs_transport->flush_mrs();
343 return (0);
344 }
345
346 /*
347 * Look up the MR given its R_key and remove it from the rbtree
348 * so nobody else finds it.
349 * This should also prevent races with rdsv3_rdma_unuse.
350 */
351 mutex_enter(&rs->rs_rdma_lock);
352 mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys,
353 rdsv3_rdma_cookie_key(args.cookie), NULL);
354 if (mr) {
355 avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
356 RB_CLEAR_NODE(&mr->r_rb_node);
357 if (args.flags & RDS_RDMA_INVALIDATE)
358 mr->r_invalidate = 1;
359 }
360 mutex_exit(&rs->rs_rdma_lock);
361
362 if (!mr)
363 return (-EINVAL);
364
365 /*
366 * call rdsv3_destroy_mr() ourselves so that we're sure it's done
367 * by time we return. If we let rdsv3_mr_put() do it it might not
368 * happen until someone else drops their ref.
369 */
370 rdsv3_destroy_mr(mr);
371 rdsv3_mr_put(mr);
372 return (0);
373 }
374
375 /*
376 * This is called when we receive an extension header that
377 * tells us this MR was used. It allows us to implement
378 * use_once semantics
379 */
380 void
rdsv3_rdma_unuse(struct rdsv3_sock * rs,uint32_t r_key,int force)381 rdsv3_rdma_unuse(struct rdsv3_sock *rs, uint32_t r_key, int force)
382 {
383 struct rdsv3_mr *mr;
384 int zot_me = 0;
385
386 RDSV3_DPRINTF4("rdsv3_rdma_unuse", "Enter rkey: 0x%x", r_key);
387
388 mutex_enter(&rs->rs_rdma_lock);
389 mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
390 if (!mr) {
391 RDSV3_DPRINTF4("rdsv3_rdma_unuse",
392 "rdsv3: trying to unuse MR with unknown r_key %u!", r_key);
393 mutex_exit(&rs->rs_rdma_lock);
394 return;
395 }
396
397 if (mr->r_use_once || force) {
398 avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
399 RB_CLEAR_NODE(&mr->r_rb_node);
400 zot_me = 1;
401 } else {
402 atomic_inc_32(&mr->r_refcount);
403 }
404 mutex_exit(&rs->rs_rdma_lock);
405
406 /*
407 * May have to issue a dma_sync on this memory region.
408 * Note we could avoid this if the operation was a RDMA READ,
409 * but at this point we can't tell.
410 */
411 if (mr->r_trans->sync_mr)
412 mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
413
414 /*
415 * If the MR was marked as invalidate, this will
416 * trigger an async flush.
417 */
418 if (zot_me)
419 rdsv3_destroy_mr(mr);
420 rdsv3_mr_put(mr);
421 RDSV3_DPRINTF4("rdsv3_rdma_unuse", "Return");
422 }
423
424 void
rdsv3_rdma_free_op(struct rdsv3_rdma_op * ro)425 rdsv3_rdma_free_op(struct rdsv3_rdma_op *ro)
426 {
427 unsigned int i;
428
429 /* deallocate RDMA resources on rdsv3_message */
430 for (i = 0; i < ro->r_nents; i++) {
431 ddi_umem_unlock(ro->r_rdma_sg[i].umem_cookie);
432 }
433
434 if (ro->r_notifier)
435 kmem_free(ro->r_notifier, sizeof (*ro->r_notifier));
436 kmem_free(ro, sizeof (*ro));
437 }
438
439 /*
440 * args is a pointer to an in-kernel copy in the sendmsg cmsg.
441 */
442 static struct rdsv3_rdma_op *
rdsv3_rdma_prepare(struct rdsv3_sock * rs,struct rds_rdma_args * args)443 rdsv3_rdma_prepare(struct rdsv3_sock *rs, struct rds_rdma_args *args)
444 {
445 struct rds_iovec vec;
446 struct rdsv3_rdma_op *op = NULL;
447 unsigned int nr_bytes;
448 struct rds_iovec *local_vec;
449 unsigned int nr;
450 unsigned int i;
451 ddi_umem_cookie_t umem_cookie;
452 size_t umem_len;
453 caddr_t umem_addr;
454 int ret;
455
456 if (rs->rs_bound_addr == 0) {
457 ret = -ENOTCONN; /* XXX not a great errno */
458 goto out;
459 }
460
461 if (args->nr_local > (uint64_t)UINT_MAX) {
462 ret = -EMSGSIZE;
463 goto out;
464 }
465
466 op = kmem_zalloc(offsetof(struct rdsv3_rdma_op,
467 r_rdma_sg[args->nr_local]), KM_NOSLEEP);
468 if (op == NULL) {
469 ret = -ENOMEM;
470 goto out;
471 }
472
473 op->r_write = !!(args->flags & RDS_RDMA_READWRITE);
474 op->r_fence = !!(args->flags & RDS_RDMA_FENCE);
475 op->r_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
476 op->r_recverr = rs->rs_recverr;
477
478 if (op->r_notify || op->r_recverr) {
479 /*
480 * We allocate an uninitialized notifier here, because
481 * we don't want to do that in the completion handler. We
482 * would have to use GFP_ATOMIC there, and don't want to deal
483 * with failed allocations.
484 */
485 op->r_notifier = kmem_alloc(sizeof (struct rdsv3_notifier),
486 KM_NOSLEEP);
487 if (!op->r_notifier) {
488 ret = -ENOMEM;
489 goto out;
490 }
491 op->r_notifier->n_user_token = args->user_token;
492 op->r_notifier->n_status = RDS_RDMA_SUCCESS;
493 }
494
495 /*
496 * The cookie contains the R_Key of the remote memory region, and
497 * optionally an offset into it. This is how we implement RDMA into
498 * unaligned memory.
499 * When setting up the RDMA, we need to add that offset to the
500 * destination address (which is really an offset into the MR)
501 * FIXME: We may want to move this into ib_rdma.c
502 */
503 op->r_key = rdsv3_rdma_cookie_key(args->cookie);
504 op->r_remote_addr = args->remote_vec.addr +
505 rdsv3_rdma_cookie_offset(args->cookie);
506
507 nr_bytes = 0;
508
509 RDSV3_DPRINTF5("rdsv3_rdma_prepare",
510 "RDS: rdma prepare nr_local %llu rva %llx rkey %x",
511 (unsigned long long)args->nr_local,
512 (unsigned long long)args->remote_vec.addr,
513 op->r_key);
514
515 local_vec = (struct rds_iovec *)(unsigned long) args->local_vec_addr;
516
517 /* pin the scatter list of user buffers */
518 for (i = 0; i < args->nr_local; i++) {
519 if (ddi_copyin(&local_vec[i], &vec,
520 sizeof (struct rds_iovec), 0)) {
521 ret = -EFAULT;
522 goto out;
523 }
524
525 nr = rdsv3_pages_in_vec(&vec);
526 if (nr == 0) {
527 RDSV3_DPRINTF2("rdsv3_rdma_prepare",
528 "rdsv3_pages_in_vec returned 0");
529 ret = -EINVAL;
530 goto out;
531 }
532
533 rs->rs_user_addr = vec.addr;
534 rs->rs_user_bytes = vec.bytes;
535
536 /* pin user memory pages */
537 umem_len = ptob(btopr(vec.bytes +
538 ((uintptr_t)vec.addr & PAGEOFFSET)));
539 umem_addr = (caddr_t)((uintptr_t)vec.addr & ~PAGEOFFSET);
540 ret = umem_lockmemory(umem_addr, umem_len,
541 DDI_UMEMLOCK_WRITE | DDI_UMEMLOCK_READ,
542 &umem_cookie, NULL, NULL);
543 if (ret != 0) {
544 RDSV3_DPRINTF2("rdsv3_rdma_prepare",
545 "umem_lockmemory() returned %d", ret);
546 ret = -EFAULT;
547 goto out;
548 }
549 op->r_rdma_sg[i].umem_cookie = umem_cookie;
550 op->r_rdma_sg[i].iovec = vec;
551 nr_bytes += vec.bytes;
552
553 RDSV3_DPRINTF5("rdsv3_rdma_prepare",
554 "RDS: nr_bytes %u nr %u vec.bytes %llu vec.addr %llx",
555 nr_bytes, nr, vec.bytes, vec.addr);
556 }
557 op->r_nents = i;
558
559 if (nr_bytes > args->remote_vec.bytes) {
560 RDSV3_DPRINTF2("rdsv3_rdma_prepare",
561 "RDS nr_bytes %u remote_bytes %u do not match",
562 nr_bytes, (unsigned int) args->remote_vec.bytes);
563 ret = -EINVAL;
564 goto out;
565 }
566 op->r_bytes = nr_bytes;
567
568 ret = 0;
569 out:
570 if (ret) {
571 if (op)
572 rdsv3_rdma_free_op(op);
573 op = ERR_PTR(ret);
574 }
575 return (op);
576 }
577
578 #define CEIL(x, y) (((x) + (y) - 1) / (y))
579
580 /*
581 * The application asks for a RDMA transfer.
582 * Extract all arguments and set up the rdma_op
583 */
584 int
rdsv3_cmsg_rdma_args(struct rdsv3_sock * rs,struct rdsv3_message * rm,struct cmsghdr * cmsg)585 rdsv3_cmsg_rdma_args(struct rdsv3_sock *rs, struct rdsv3_message *rm,
586 struct cmsghdr *cmsg)
587 {
588 struct rdsv3_rdma_op *op;
589 /* uint64_t alignment on the buffer */
590 uint64_t buf[CEIL(CMSG_LEN(sizeof (struct rds_rdma_args)),
591 sizeof (uint64_t))];
592
593 if (cmsg->cmsg_len != CMSG_LEN(sizeof (struct rds_rdma_args)) ||
594 rm->m_rdma_op != NULL)
595 return (-EINVAL);
596
597 ASSERT(sizeof (buf) >= cmsg->cmsg_len && ((uintptr_t)buf & 0x7) == 0);
598
599 bcopy(CMSG_DATA(cmsg), (char *)buf, cmsg->cmsg_len);
600 op = rdsv3_rdma_prepare(rs, (struct rds_rdma_args *)buf);
601
602 if (IS_ERR(op))
603 return (PTR_ERR(op));
604 rdsv3_stats_inc(s_send_rdma);
605 rm->m_rdma_op = op;
606 return (0);
607 }
608
609 /*
610 * The application wants us to pass an RDMA destination (aka MR)
611 * to the remote
612 */
613 int
rdsv3_cmsg_rdma_dest(struct rdsv3_sock * rs,struct rdsv3_message * rm,struct cmsghdr * cmsg)614 rdsv3_cmsg_rdma_dest(struct rdsv3_sock *rs, struct rdsv3_message *rm,
615 struct cmsghdr *cmsg)
616 {
617 struct rdsv3_mr *mr;
618 uint32_t r_key;
619 int err = 0;
620
621 if (cmsg->cmsg_len != CMSG_LEN(sizeof (rds_rdma_cookie_t)) ||
622 rm->m_rdma_cookie != 0)
623 return (-EINVAL);
624
625 (void) memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg),
626 sizeof (rm->m_rdma_cookie));
627
628 /*
629 * We are reusing a previously mapped MR here. Most likely, the
630 * application has written to the buffer, so we need to explicitly
631 * flush those writes to RAM. Otherwise the HCA may not see them
632 * when doing a DMA from that buffer.
633 */
634 r_key = rdsv3_rdma_cookie_key(rm->m_rdma_cookie);
635
636 mutex_enter(&rs->rs_rdma_lock);
637 mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
638 if (!mr)
639 err = -EINVAL; /* invalid r_key */
640 else
641 atomic_inc_32(&mr->r_refcount);
642 mutex_exit(&rs->rs_rdma_lock);
643
644 if (mr) {
645 mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
646 rm->m_rdma_mr = mr;
647 }
648 return (err);
649 }
650
651 /*
652 * The application passes us an address range it wants to enable RDMA
653 * to/from. We map the area, and save the <R_Key,offset> pair
654 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
655 * in an extension header.
656 */
657 int
rdsv3_cmsg_rdma_map(struct rdsv3_sock * rs,struct rdsv3_message * rm,struct cmsghdr * cmsg)658 rdsv3_cmsg_rdma_map(struct rdsv3_sock *rs, struct rdsv3_message *rm,
659 struct cmsghdr *cmsg)
660 {
661 /* uint64_t alignment on the buffer */
662 uint64_t buf[CEIL(CMSG_LEN(sizeof (struct rds_get_mr_args)),
663 sizeof (uint64_t))];
664 int status;
665
666 if (cmsg->cmsg_len != CMSG_LEN(sizeof (struct rds_get_mr_args)) ||
667 rm->m_rdma_cookie != 0)
668 return (-EINVAL);
669
670 ASSERT(sizeof (buf) >= cmsg->cmsg_len && ((uintptr_t)buf & 0x7) == 0);
671
672 bcopy(CMSG_DATA(cmsg), (char *)buf, cmsg->cmsg_len);
673 status = __rdsv3_rdma_map(rs, (struct rds_get_mr_args *)buf,
674 &rm->m_rdma_cookie, &rm->m_rdma_mr);
675
676 return (status);
677 }
678