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 #include <sys/containerof.h>
52
53 #define DMA_TO_DEVICE 0
54 #define DMA_FROM_DEVICE 1
55 #define RB_CLEAR_NODE(nodep) AVL_SETPARENT(nodep, nodep);
56
57 /*
58 * XXX
59 * - build with sparse
60 * - should we limit the size of a mr region? let transport return failure?
61 * - should we detect duplicate keys on a socket? hmm.
62 * - an rdma is an mlock, apply rlimit?
63 */
64
65 /*
66 * get the number of pages by looking at the page indices that the start and
67 * end addresses fall in.
68 *
69 * Returns 0 if the vec is invalid. It is invalid if the number of bytes
70 * causes the address to wrap or overflows an unsigned int. This comes
71 * from being stored in the 'length' member of 'struct rdsv3_scatterlist'.
72 */
73 static unsigned int
rdsv3_pages_in_vec(struct rds_iovec * vec)74 rdsv3_pages_in_vec(struct rds_iovec *vec)
75 {
76 if ((vec->addr + vec->bytes <= vec->addr) ||
77 (vec->bytes > (uint64_t)UINT_MAX)) {
78 return (0);
79 }
80
81 return (((vec->addr + vec->bytes + PAGESIZE - 1) >>
82 PAGESHIFT) - (vec->addr >> PAGESHIFT));
83 }
84
85 static struct rdsv3_mr *
rdsv3_mr_tree_walk(struct avl_tree * root,uint32_t key,struct rdsv3_mr * insert)86 rdsv3_mr_tree_walk(struct avl_tree *root, uint32_t key,
87 struct rdsv3_mr *insert)
88 {
89 struct rdsv3_mr *mr;
90 avl_index_t where;
91
92 mr = avl_find(root, &key, &where);
93 if ((mr == NULL) && (insert != NULL)) {
94 avl_insert(root, (void *)insert, where);
95 atomic_inc_32(&insert->r_refcount);
96 return (NULL);
97 }
98
99 return (mr);
100 }
101
102 /*
103 * Destroy the transport-specific part of a MR.
104 */
105 static void
rdsv3_destroy_mr(struct rdsv3_mr * mr)106 rdsv3_destroy_mr(struct rdsv3_mr *mr)
107 {
108 struct rdsv3_sock *rs = mr->r_sock;
109 void *trans_private = NULL;
110 avl_node_t *np;
111
112 RDSV3_DPRINTF5("rdsv3_destroy_mr",
113 "RDS: destroy mr key is %x refcnt %u",
114 mr->r_key, atomic_get(&mr->r_refcount));
115
116 if (test_and_set_bit(RDSV3_MR_DEAD, &mr->r_state))
117 return;
118
119 mutex_enter(&rs->rs_rdma_lock);
120 np = &mr->r_rb_node;
121 if (AVL_XPARENT(np) != np)
122 avl_remove(&rs->rs_rdma_keys, mr);
123 trans_private = mr->r_trans_private;
124 mr->r_trans_private = NULL;
125 mutex_exit(&rs->rs_rdma_lock);
126
127 if (trans_private)
128 mr->r_trans->free_mr(trans_private, mr->r_invalidate);
129 }
130
131 void
__rdsv3_put_mr_final(struct rdsv3_mr * mr)132 __rdsv3_put_mr_final(struct rdsv3_mr *mr)
133 {
134 rdsv3_destroy_mr(mr);
135 kmem_free(mr, sizeof (*mr));
136 }
137
138 /*
139 * By the time this is called we can't have any more ioctls called on
140 * the socket so we don't need to worry about racing with others.
141 */
142 void
rdsv3_rdma_drop_keys(struct rdsv3_sock * rs)143 rdsv3_rdma_drop_keys(struct rdsv3_sock *rs)
144 {
145 struct rdsv3_mr *mr;
146 struct avl_node *node;
147
148 /* Release any MRs associated with this socket */
149 mutex_enter(&rs->rs_rdma_lock);
150 while ((node = avl_first(&rs->rs_rdma_keys))) {
151 mr = __containerof(node, struct rdsv3_mr, r_rb_node);
152 if (mr->r_trans == rs->rs_transport)
153 mr->r_invalidate = 0;
154 avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
155 RB_CLEAR_NODE(&mr->r_rb_node)
156 mutex_exit(&rs->rs_rdma_lock);
157 rdsv3_destroy_mr(mr);
158 rdsv3_mr_put(mr);
159 mutex_enter(&rs->rs_rdma_lock);
160 }
161 mutex_exit(&rs->rs_rdma_lock);
162
163 if (rs->rs_transport && rs->rs_transport->flush_mrs)
164 rs->rs_transport->flush_mrs();
165 }
166
167 static int
__rdsv3_rdma_map(struct rdsv3_sock * rs,struct rds_get_mr_args * args,uint64_t * cookie_ret,struct rdsv3_mr ** mr_ret)168 __rdsv3_rdma_map(struct rdsv3_sock *rs, struct rds_get_mr_args *args,
169 uint64_t *cookie_ret, struct rdsv3_mr **mr_ret)
170 {
171 struct rdsv3_mr *mr = NULL, *found;
172 void *trans_private;
173 rds_rdma_cookie_t cookie;
174 unsigned int nents = 0;
175 int ret;
176
177 if (rs->rs_bound_addr == 0) {
178 ret = -ENOTCONN; /* XXX not a great errno */
179 goto out;
180 }
181
182 if (!rs->rs_transport->get_mr) {
183 ret = -EOPNOTSUPP;
184 goto out;
185 }
186
187 mr = kmem_zalloc(sizeof (struct rdsv3_mr), KM_NOSLEEP);
188 if (!mr) {
189 ret = -ENOMEM;
190 goto out;
191 }
192
193 mr->r_refcount = 1;
194 RB_CLEAR_NODE(&mr->r_rb_node);
195 mr->r_trans = rs->rs_transport;
196 mr->r_sock = rs;
197
198 if (args->flags & RDS_RDMA_USE_ONCE)
199 mr->r_use_once = 1;
200 if (args->flags & RDS_RDMA_INVALIDATE)
201 mr->r_invalidate = 1;
202 if (args->flags & RDS_RDMA_READWRITE)
203 mr->r_write = 1;
204
205 /*
206 * Obtain a transport specific MR. If this succeeds, the
207 * s/g list is now owned by the MR.
208 * Note that dma_map() implies that pending writes are
209 * flushed to RAM, so no dma_sync is needed here.
210 */
211 trans_private = rs->rs_transport->get_mr(&args->vec, nents, rs,
212 &mr->r_key);
213
214 if (IS_ERR(trans_private)) {
215 ret = PTR_ERR(trans_private);
216 goto out;
217 }
218
219 mr->r_trans_private = trans_private;
220
221 /*
222 * The user may pass us an unaligned address, but we can only
223 * map page aligned regions. So we keep the offset, and build
224 * a 64bit cookie containing <R_Key, offset> and pass that
225 * around.
226 */
227 cookie = rdsv3_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGEMASK);
228 if (cookie_ret)
229 *cookie_ret = cookie;
230
231 /*
232 * copy value of cookie to user address at args->cookie_addr
233 */
234 if (args->cookie_addr) {
235 ret = ddi_copyout((void *)&cookie,
236 (void *)((intptr_t)args->cookie_addr),
237 sizeof (rds_rdma_cookie_t), 0);
238 if (ret != 0) {
239 ret = -EFAULT;
240 goto out;
241 }
242 }
243
244 RDSV3_DPRINTF5("__rdsv3_rdma_map",
245 "RDS: get_mr mr 0x%p addr 0x%llx key 0x%x",
246 mr, args->vec.addr, mr->r_key);
247 /*
248 * Inserting the new MR into the rbtree bumps its
249 * reference count.
250 */
251 mutex_enter(&rs->rs_rdma_lock);
252 found = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
253 mutex_exit(&rs->rs_rdma_lock);
254
255 ASSERT(!(found && found != mr));
256
257 if (mr_ret) {
258 atomic_inc_32(&mr->r_refcount);
259 *mr_ret = mr;
260 }
261
262 ret = 0;
263 out:
264 if (mr)
265 rdsv3_mr_put(mr);
266 return (ret);
267 }
268
269 int
rdsv3_get_mr(struct rdsv3_sock * rs,const void * optval,int optlen)270 rdsv3_get_mr(struct rdsv3_sock *rs, const void *optval, int optlen)
271 {
272 struct rds_get_mr_args args;
273
274 if (optlen != sizeof (struct rds_get_mr_args))
275 return (-EINVAL);
276
277 #if 1
278 bcopy((struct rds_get_mr_args *)optval, &args,
279 sizeof (struct rds_get_mr_args));
280 #else
281 if (ddi_copyin(optval, &args, optlen, 0))
282 return (-EFAULT);
283 #endif
284
285 return (__rdsv3_rdma_map(rs, &args, NULL, NULL));
286 }
287
288 int
rdsv3_get_mr_for_dest(struct rdsv3_sock * rs,const void * optval,int optlen)289 rdsv3_get_mr_for_dest(struct rdsv3_sock *rs, const void *optval,
290 int optlen)
291 {
292 struct rds_get_mr_for_dest_args args;
293 struct rds_get_mr_args new_args;
294
295 if (optlen != sizeof (struct rds_get_mr_for_dest_args))
296 return (-EINVAL);
297
298 #if 1
299 bcopy((struct rds_get_mr_for_dest_args *)optval, &args,
300 sizeof (struct rds_get_mr_for_dest_args));
301 #else
302 if (ddi_copyin(optval, &args, optlen, 0))
303 return (-EFAULT);
304 #endif
305
306 /*
307 * Initially, just behave like get_mr().
308 * TODO: Implement get_mr as wrapper around this
309 * and deprecate it.
310 */
311 new_args.vec = args.vec;
312 new_args.cookie_addr = args.cookie_addr;
313 new_args.flags = args.flags;
314
315 return (__rdsv3_rdma_map(rs, &new_args, NULL, NULL));
316 }
317
318 /*
319 * Free the MR indicated by the given R_Key
320 */
321 int
rdsv3_free_mr(struct rdsv3_sock * rs,const void * optval,int optlen)322 rdsv3_free_mr(struct rdsv3_sock *rs, const void *optval, int optlen)
323 {
324 struct rds_free_mr_args args;
325 struct rdsv3_mr *mr;
326
327 if (optlen != sizeof (struct rds_free_mr_args))
328 return (-EINVAL);
329
330 #if 1
331 bcopy((struct rds_free_mr_args *)optval, &args,
332 sizeof (struct rds_free_mr_args));
333 #else
334 if (ddi_copyin((struct rds_free_mr_args *)optval, &args,
335 sizeof (struct rds_free_mr_args), 0))
336 return (-EFAULT);
337 #endif
338
339 /* Special case - a null cookie means flush all unused MRs */
340 if (args.cookie == 0) {
341 if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
342 return (-EINVAL);
343 rs->rs_transport->flush_mrs();
344 return (0);
345 }
346
347 /*
348 * Look up the MR given its R_key and remove it from the rbtree
349 * so nobody else finds it.
350 * This should also prevent races with rdsv3_rdma_unuse.
351 */
352 mutex_enter(&rs->rs_rdma_lock);
353 mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys,
354 rdsv3_rdma_cookie_key(args.cookie), NULL);
355 if (mr) {
356 avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
357 RB_CLEAR_NODE(&mr->r_rb_node);
358 if (args.flags & RDS_RDMA_INVALIDATE)
359 mr->r_invalidate = 1;
360 }
361 mutex_exit(&rs->rs_rdma_lock);
362
363 if (!mr)
364 return (-EINVAL);
365
366 /*
367 * call rdsv3_destroy_mr() ourselves so that we're sure it's done
368 * by time we return. If we let rdsv3_mr_put() do it it might not
369 * happen until someone else drops their ref.
370 */
371 rdsv3_destroy_mr(mr);
372 rdsv3_mr_put(mr);
373 return (0);
374 }
375
376 /*
377 * This is called when we receive an extension header that
378 * tells us this MR was used. It allows us to implement
379 * use_once semantics
380 */
381 void
rdsv3_rdma_unuse(struct rdsv3_sock * rs,uint32_t r_key,int force)382 rdsv3_rdma_unuse(struct rdsv3_sock *rs, uint32_t r_key, int force)
383 {
384 struct rdsv3_mr *mr;
385 int zot_me = 0;
386
387 RDSV3_DPRINTF4("rdsv3_rdma_unuse", "Enter rkey: 0x%x", r_key);
388
389 mutex_enter(&rs->rs_rdma_lock);
390 mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
391 if (!mr) {
392 RDSV3_DPRINTF4("rdsv3_rdma_unuse",
393 "rdsv3: trying to unuse MR with unknown r_key %u!", r_key);
394 mutex_exit(&rs->rs_rdma_lock);
395 return;
396 }
397
398 if (mr->r_use_once || force) {
399 avl_remove(&rs->rs_rdma_keys, &mr->r_rb_node);
400 RB_CLEAR_NODE(&mr->r_rb_node);
401 zot_me = 1;
402 } else {
403 atomic_inc_32(&mr->r_refcount);
404 }
405 mutex_exit(&rs->rs_rdma_lock);
406
407 /*
408 * May have to issue a dma_sync on this memory region.
409 * Note we could avoid this if the operation was a RDMA READ,
410 * but at this point we can't tell.
411 */
412 if (mr->r_trans->sync_mr)
413 mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
414
415 /*
416 * If the MR was marked as invalidate, this will
417 * trigger an async flush.
418 */
419 if (zot_me)
420 rdsv3_destroy_mr(mr);
421 rdsv3_mr_put(mr);
422 RDSV3_DPRINTF4("rdsv3_rdma_unuse", "Return");
423 }
424
425 void
rdsv3_rdma_free_op(struct rdsv3_rdma_op * ro)426 rdsv3_rdma_free_op(struct rdsv3_rdma_op *ro)
427 {
428 unsigned int i;
429
430 /* deallocate RDMA resources on rdsv3_message */
431 for (i = 0; i < ro->r_nents; i++) {
432 ddi_umem_unlock(ro->r_rdma_sg[i].umem_cookie);
433 }
434
435 if (ro->r_notifier)
436 kmem_free(ro->r_notifier, sizeof (*ro->r_notifier));
437 kmem_free(ro, sizeof (*ro));
438 }
439
440 /*
441 * args is a pointer to an in-kernel copy in the sendmsg cmsg.
442 */
443 static struct rdsv3_rdma_op *
rdsv3_rdma_prepare(struct rdsv3_sock * rs,struct rds_rdma_args * args)444 rdsv3_rdma_prepare(struct rdsv3_sock *rs, struct rds_rdma_args *args)
445 {
446 struct rds_iovec vec;
447 struct rdsv3_rdma_op *op = NULL;
448 unsigned int nr_bytes;
449 struct rds_iovec *local_vec;
450 unsigned int nr;
451 unsigned int i;
452 ddi_umem_cookie_t umem_cookie;
453 size_t umem_len;
454 caddr_t umem_addr;
455 int ret;
456
457 if (rs->rs_bound_addr == 0) {
458 ret = -ENOTCONN; /* XXX not a great errno */
459 goto out;
460 }
461
462 if (args->nr_local > (uint64_t)UINT_MAX) {
463 ret = -EMSGSIZE;
464 goto out;
465 }
466
467 op = kmem_zalloc(offsetof(struct rdsv3_rdma_op,
468 r_rdma_sg[args->nr_local]), KM_NOSLEEP);
469 if (op == NULL) {
470 ret = -ENOMEM;
471 goto out;
472 }
473
474 op->r_write = !!(args->flags & RDS_RDMA_READWRITE);
475 op->r_fence = !!(args->flags & RDS_RDMA_FENCE);
476 op->r_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
477 op->r_recverr = rs->rs_recverr;
478
479 if (op->r_notify || op->r_recverr) {
480 /*
481 * We allocate an uninitialized notifier here, because
482 * we don't want to do that in the completion handler. We
483 * would have to use GFP_ATOMIC there, and don't want to deal
484 * with failed allocations.
485 */
486 op->r_notifier = kmem_alloc(sizeof (struct rdsv3_notifier),
487 KM_NOSLEEP);
488 if (!op->r_notifier) {
489 ret = -ENOMEM;
490 goto out;
491 }
492 op->r_notifier->n_user_token = args->user_token;
493 op->r_notifier->n_status = RDS_RDMA_SUCCESS;
494 }
495
496 /*
497 * The cookie contains the R_Key of the remote memory region, and
498 * optionally an offset into it. This is how we implement RDMA into
499 * unaligned memory.
500 * When setting up the RDMA, we need to add that offset to the
501 * destination address (which is really an offset into the MR)
502 * FIXME: We may want to move this into ib_rdma.c
503 */
504 op->r_key = rdsv3_rdma_cookie_key(args->cookie);
505 op->r_remote_addr = args->remote_vec.addr +
506 rdsv3_rdma_cookie_offset(args->cookie);
507
508 nr_bytes = 0;
509
510 RDSV3_DPRINTF5("rdsv3_rdma_prepare",
511 "RDS: rdma prepare nr_local %llu rva %llx rkey %x",
512 (unsigned long long)args->nr_local,
513 (unsigned long long)args->remote_vec.addr,
514 op->r_key);
515
516 local_vec = (struct rds_iovec *)(unsigned long) args->local_vec_addr;
517
518 /* pin the scatter list of user buffers */
519 for (i = 0; i < args->nr_local; i++) {
520 if (ddi_copyin(&local_vec[i], &vec,
521 sizeof (struct rds_iovec), 0)) {
522 ret = -EFAULT;
523 goto out;
524 }
525
526 nr = rdsv3_pages_in_vec(&vec);
527 if (nr == 0) {
528 RDSV3_DPRINTF2("rdsv3_rdma_prepare",
529 "rdsv3_pages_in_vec returned 0");
530 ret = -EINVAL;
531 goto out;
532 }
533
534 rs->rs_user_addr = vec.addr;
535 rs->rs_user_bytes = vec.bytes;
536
537 /* pin user memory pages */
538 umem_len = ptob(btopr(vec.bytes +
539 ((uintptr_t)vec.addr & PAGEOFFSET)));
540 umem_addr = (caddr_t)((uintptr_t)vec.addr & ~PAGEOFFSET);
541 ret = umem_lockmemory(umem_addr, umem_len,
542 DDI_UMEMLOCK_WRITE | DDI_UMEMLOCK_READ,
543 &umem_cookie, NULL, NULL);
544 if (ret != 0) {
545 RDSV3_DPRINTF2("rdsv3_rdma_prepare",
546 "umem_lockmemory() returned %d", ret);
547 ret = -EFAULT;
548 goto out;
549 }
550 op->r_rdma_sg[i].umem_cookie = umem_cookie;
551 op->r_rdma_sg[i].iovec = vec;
552 nr_bytes += vec.bytes;
553
554 RDSV3_DPRINTF5("rdsv3_rdma_prepare",
555 "RDS: nr_bytes %u nr %u vec.bytes %llu vec.addr %llx",
556 nr_bytes, nr, vec.bytes, vec.addr);
557 }
558 op->r_nents = i;
559
560 if (nr_bytes > args->remote_vec.bytes) {
561 RDSV3_DPRINTF2("rdsv3_rdma_prepare",
562 "RDS nr_bytes %u remote_bytes %u do not match",
563 nr_bytes, (unsigned int) args->remote_vec.bytes);
564 ret = -EINVAL;
565 goto out;
566 }
567 op->r_bytes = nr_bytes;
568
569 ret = 0;
570 out:
571 if (ret) {
572 if (op)
573 rdsv3_rdma_free_op(op);
574 op = ERR_PTR(ret);
575 }
576 return (op);
577 }
578
579 #define CEIL(x, y) (((x) + (y) - 1) / (y))
580
581 /*
582 * The application asks for a RDMA transfer.
583 * Extract all arguments and set up the rdma_op
584 */
585 int
rdsv3_cmsg_rdma_args(struct rdsv3_sock * rs,struct rdsv3_message * rm,struct cmsghdr * cmsg)586 rdsv3_cmsg_rdma_args(struct rdsv3_sock *rs, struct rdsv3_message *rm,
587 struct cmsghdr *cmsg)
588 {
589 struct rdsv3_rdma_op *op;
590 /* uint64_t alignment on the buffer */
591 uint64_t buf[CEIL(CMSG_LEN(sizeof (struct rds_rdma_args)),
592 sizeof (uint64_t))];
593
594 if (cmsg->cmsg_len != CMSG_LEN(sizeof (struct rds_rdma_args)) ||
595 rm->m_rdma_op != NULL)
596 return (-EINVAL);
597
598 ASSERT(sizeof (buf) >= cmsg->cmsg_len && ((uintptr_t)buf & 0x7) == 0);
599
600 bcopy(CMSG_DATA(cmsg), (char *)buf, cmsg->cmsg_len);
601 op = rdsv3_rdma_prepare(rs, (struct rds_rdma_args *)buf);
602
603 if (IS_ERR(op))
604 return (PTR_ERR(op));
605 rdsv3_stats_inc(s_send_rdma);
606 rm->m_rdma_op = op;
607 return (0);
608 }
609
610 /*
611 * The application wants us to pass an RDMA destination (aka MR)
612 * to the remote
613 */
614 int
rdsv3_cmsg_rdma_dest(struct rdsv3_sock * rs,struct rdsv3_message * rm,struct cmsghdr * cmsg)615 rdsv3_cmsg_rdma_dest(struct rdsv3_sock *rs, struct rdsv3_message *rm,
616 struct cmsghdr *cmsg)
617 {
618 struct rdsv3_mr *mr;
619 uint32_t r_key;
620 int err = 0;
621
622 if (cmsg->cmsg_len != CMSG_LEN(sizeof (rds_rdma_cookie_t)) ||
623 rm->m_rdma_cookie != 0)
624 return (-EINVAL);
625
626 (void) memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg),
627 sizeof (rm->m_rdma_cookie));
628
629 /*
630 * We are reusing a previously mapped MR here. Most likely, the
631 * application has written to the buffer, so we need to explicitly
632 * flush those writes to RAM. Otherwise the HCA may not see them
633 * when doing a DMA from that buffer.
634 */
635 r_key = rdsv3_rdma_cookie_key(rm->m_rdma_cookie);
636
637 mutex_enter(&rs->rs_rdma_lock);
638 mr = rdsv3_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
639 if (!mr)
640 err = -EINVAL; /* invalid r_key */
641 else
642 atomic_inc_32(&mr->r_refcount);
643 mutex_exit(&rs->rs_rdma_lock);
644
645 if (mr) {
646 mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
647 rm->m_rdma_mr = mr;
648 }
649 return (err);
650 }
651
652 /*
653 * The application passes us an address range it wants to enable RDMA
654 * to/from. We map the area, and save the <R_Key,offset> pair
655 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
656 * in an extension header.
657 */
658 int
rdsv3_cmsg_rdma_map(struct rdsv3_sock * rs,struct rdsv3_message * rm,struct cmsghdr * cmsg)659 rdsv3_cmsg_rdma_map(struct rdsv3_sock *rs, struct rdsv3_message *rm,
660 struct cmsghdr *cmsg)
661 {
662 /* uint64_t alignment on the buffer */
663 uint64_t buf[CEIL(CMSG_LEN(sizeof (struct rds_get_mr_args)),
664 sizeof (uint64_t))];
665 int status;
666
667 if (cmsg->cmsg_len != CMSG_LEN(sizeof (struct rds_get_mr_args)) ||
668 rm->m_rdma_cookie != 0)
669 return (-EINVAL);
670
671 ASSERT(sizeof (buf) >= cmsg->cmsg_len && ((uintptr_t)buf & 0x7) == 0);
672
673 bcopy(CMSG_DATA(cmsg), (char *)buf, cmsg->cmsg_len);
674 status = __rdsv3_rdma_map(rs, (struct rds_get_mr_args *)buf,
675 &rm->m_rdma_cookie, &rm->m_rdma_mr);
676
677 return (status);
678 }
679