1 /*
2 * Copyright (c) 2007, 2017 Oracle and/or its affiliates. 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/slab.h>
35 #include <linux/rbtree.h>
36 #include <linux/dma-mapping.h> /* for DMA_*_DEVICE */
37
38 #include "rds.h"
39
40 /*
41 * XXX
42 * - build with sparse
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 */
rds_pages_in_vec(struct rds_iovec * vec)55 static 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
rds_mr_tree_walk(struct rb_root * root,u64 key,struct rds_mr * insert)65 static 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 refcount_inc(&insert->r_refcount);
88 }
89 return NULL;
90 }
91
92 /*
93 * Destroy the transport-specific part of a MR.
94 */
rds_destroy_mr(struct rds_mr * mr)95 static 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, refcount_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
__rds_put_mr_final(struct rds_mr * mr)118 void __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 */
rds_rdma_drop_keys(struct rds_sock * rs)128 void rds_rdma_drop_keys(struct rds_sock *rs)
129 {
130 struct rds_mr *mr;
131 struct rb_node *node;
132 unsigned long flags;
133
134 /* Release any MRs associated with this socket */
135 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
136 while ((node = rb_first(&rs->rs_rdma_keys))) {
137 mr = rb_entry(node, struct rds_mr, r_rb_node);
138 if (mr->r_trans == rs->rs_transport)
139 mr->r_invalidate = 0;
140 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
141 RB_CLEAR_NODE(&mr->r_rb_node);
142 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
143 rds_destroy_mr(mr);
144 rds_mr_put(mr);
145 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
146 }
147 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
148
149 if (rs->rs_transport && rs->rs_transport->flush_mrs)
150 rs->rs_transport->flush_mrs();
151 }
152
153 /*
154 * Helper function to pin user pages.
155 */
rds_pin_pages(unsigned long user_addr,unsigned int nr_pages,struct page ** pages,int write)156 static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages,
157 struct page **pages, int write)
158 {
159 int ret;
160
161 ret = get_user_pages_fast(user_addr, nr_pages, write ? FOLL_WRITE : 0,
162 pages);
163
164 if (ret >= 0 && ret < nr_pages) {
165 while (ret--)
166 put_page(pages[ret]);
167 ret = -EFAULT;
168 }
169
170 return ret;
171 }
172
__rds_rdma_map(struct rds_sock * rs,struct rds_get_mr_args * args,u64 * cookie_ret,struct rds_mr ** mr_ret,struct rds_conn_path * cp)173 static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
174 u64 *cookie_ret, struct rds_mr **mr_ret,
175 struct rds_conn_path *cp)
176 {
177 struct rds_mr *mr = NULL, *found;
178 unsigned int nr_pages;
179 struct page **pages = NULL;
180 struct scatterlist *sg;
181 void *trans_private;
182 unsigned long flags;
183 rds_rdma_cookie_t cookie;
184 unsigned int nents;
185 long i;
186 int ret;
187
188 if (ipv6_addr_any(&rs->rs_bound_addr) || !rs->rs_transport) {
189 ret = -ENOTCONN; /* XXX not a great errno */
190 goto out;
191 }
192
193 if (!rs->rs_transport->get_mr) {
194 ret = -EOPNOTSUPP;
195 goto out;
196 }
197
198 nr_pages = rds_pages_in_vec(&args->vec);
199 if (nr_pages == 0) {
200 ret = -EINVAL;
201 goto out;
202 }
203
204 /* Restrict the size of mr irrespective of underlying transport
205 * To account for unaligned mr regions, subtract one from nr_pages
206 */
207 if ((nr_pages - 1) > (RDS_MAX_MSG_SIZE >> PAGE_SHIFT)) {
208 ret = -EMSGSIZE;
209 goto out;
210 }
211
212 rdsdebug("RDS: get_mr addr %llx len %llu nr_pages %u\n",
213 args->vec.addr, args->vec.bytes, nr_pages);
214
215 /* XXX clamp nr_pages to limit the size of this alloc? */
216 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
217 if (!pages) {
218 ret = -ENOMEM;
219 goto out;
220 }
221
222 mr = kzalloc(sizeof(struct rds_mr), GFP_KERNEL);
223 if (!mr) {
224 ret = -ENOMEM;
225 goto out;
226 }
227
228 refcount_set(&mr->r_refcount, 1);
229 RB_CLEAR_NODE(&mr->r_rb_node);
230 mr->r_trans = rs->rs_transport;
231 mr->r_sock = rs;
232
233 if (args->flags & RDS_RDMA_USE_ONCE)
234 mr->r_use_once = 1;
235 if (args->flags & RDS_RDMA_INVALIDATE)
236 mr->r_invalidate = 1;
237 if (args->flags & RDS_RDMA_READWRITE)
238 mr->r_write = 1;
239
240 /*
241 * Pin the pages that make up the user buffer and transfer the page
242 * pointers to the mr's sg array. We check to see if we've mapped
243 * the whole region after transferring the partial page references
244 * to the sg array so that we can have one page ref cleanup path.
245 *
246 * For now we have no flag that tells us whether the mapping is
247 * r/o or r/w. We need to assume r/w, or we'll do a lot of RDMA to
248 * the zero page.
249 */
250 ret = rds_pin_pages(args->vec.addr, nr_pages, pages, 1);
251 if (ret < 0)
252 goto out;
253
254 nents = ret;
255 sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL);
256 if (!sg) {
257 ret = -ENOMEM;
258 goto out;
259 }
260 WARN_ON(!nents);
261 sg_init_table(sg, nents);
262
263 /* Stick all pages into the scatterlist */
264 for (i = 0 ; i < nents; i++)
265 sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0);
266
267 rdsdebug("RDS: trans_private nents is %u\n", nents);
268
269 /* Obtain a transport specific MR. If this succeeds, the
270 * s/g list is now owned by the MR.
271 * Note that dma_map() implies that pending writes are
272 * flushed to RAM, so no dma_sync is needed here. */
273 trans_private = rs->rs_transport->get_mr(sg, nents, rs,
274 &mr->r_key,
275 cp ? cp->cp_conn : NULL);
276
277 if (IS_ERR(trans_private)) {
278 for (i = 0 ; i < nents; i++)
279 put_page(sg_page(&sg[i]));
280 kfree(sg);
281 ret = PTR_ERR(trans_private);
282 goto out;
283 }
284
285 mr->r_trans_private = trans_private;
286
287 rdsdebug("RDS: get_mr put_user key is %x cookie_addr %p\n",
288 mr->r_key, (void *)(unsigned long) args->cookie_addr);
289
290 /* The user may pass us an unaligned address, but we can only
291 * map page aligned regions. So we keep the offset, and build
292 * a 64bit cookie containing <R_Key, offset> and pass that
293 * around. */
294 cookie = rds_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGE_MASK);
295 if (cookie_ret)
296 *cookie_ret = cookie;
297
298 if (args->cookie_addr && put_user(cookie, (u64 __user *)(unsigned long) args->cookie_addr)) {
299 ret = -EFAULT;
300 goto out;
301 }
302
303 /* Inserting the new MR into the rbtree bumps its
304 * reference count. */
305 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
306 found = rds_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
307 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
308
309 BUG_ON(found && found != mr);
310
311 rdsdebug("RDS: get_mr key is %x\n", mr->r_key);
312 if (mr_ret) {
313 refcount_inc(&mr->r_refcount);
314 *mr_ret = mr;
315 }
316
317 ret = 0;
318 out:
319 kfree(pages);
320 if (mr)
321 rds_mr_put(mr);
322 return ret;
323 }
324
rds_get_mr(struct rds_sock * rs,char __user * optval,int optlen)325 int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen)
326 {
327 struct rds_get_mr_args args;
328
329 if (optlen != sizeof(struct rds_get_mr_args))
330 return -EINVAL;
331
332 if (copy_from_user(&args, (struct rds_get_mr_args __user *)optval,
333 sizeof(struct rds_get_mr_args)))
334 return -EFAULT;
335
336 return __rds_rdma_map(rs, &args, NULL, NULL, NULL);
337 }
338
rds_get_mr_for_dest(struct rds_sock * rs,char __user * optval,int optlen)339 int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen)
340 {
341 struct rds_get_mr_for_dest_args args;
342 struct rds_get_mr_args new_args;
343
344 if (optlen != sizeof(struct rds_get_mr_for_dest_args))
345 return -EINVAL;
346
347 if (copy_from_user(&args, (struct rds_get_mr_for_dest_args __user *)optval,
348 sizeof(struct rds_get_mr_for_dest_args)))
349 return -EFAULT;
350
351 /*
352 * Initially, just behave like get_mr().
353 * TODO: Implement get_mr as wrapper around this
354 * and deprecate it.
355 */
356 new_args.vec = args.vec;
357 new_args.cookie_addr = args.cookie_addr;
358 new_args.flags = args.flags;
359
360 return __rds_rdma_map(rs, &new_args, NULL, NULL, NULL);
361 }
362
363 /*
364 * Free the MR indicated by the given R_Key
365 */
rds_free_mr(struct rds_sock * rs,char __user * optval,int optlen)366 int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen)
367 {
368 struct rds_free_mr_args args;
369 struct rds_mr *mr;
370 unsigned long flags;
371
372 if (optlen != sizeof(struct rds_free_mr_args))
373 return -EINVAL;
374
375 if (copy_from_user(&args, (struct rds_free_mr_args __user *)optval,
376 sizeof(struct rds_free_mr_args)))
377 return -EFAULT;
378
379 /* Special case - a null cookie means flush all unused MRs */
380 if (args.cookie == 0) {
381 if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
382 return -EINVAL;
383 rs->rs_transport->flush_mrs();
384 return 0;
385 }
386
387 /* Look up the MR given its R_key and remove it from the rbtree
388 * so nobody else finds it.
389 * This should also prevent races with rds_rdma_unuse.
390 */
391 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
392 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, rds_rdma_cookie_key(args.cookie), NULL);
393 if (mr) {
394 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
395 RB_CLEAR_NODE(&mr->r_rb_node);
396 if (args.flags & RDS_RDMA_INVALIDATE)
397 mr->r_invalidate = 1;
398 }
399 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
400
401 if (!mr)
402 return -EINVAL;
403
404 /*
405 * call rds_destroy_mr() ourselves so that we're sure it's done by the time
406 * we return. If we let rds_mr_put() do it it might not happen until
407 * someone else drops their ref.
408 */
409 rds_destroy_mr(mr);
410 rds_mr_put(mr);
411 return 0;
412 }
413
414 /*
415 * This is called when we receive an extension header that
416 * tells us this MR was used. It allows us to implement
417 * use_once semantics
418 */
rds_rdma_unuse(struct rds_sock * rs,u32 r_key,int force)419 void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force)
420 {
421 struct rds_mr *mr;
422 unsigned long flags;
423 int zot_me = 0;
424
425 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
426 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
427 if (!mr) {
428 pr_debug("rds: trying to unuse MR with unknown r_key %u!\n",
429 r_key);
430 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
431 return;
432 }
433
434 if (mr->r_use_once || force) {
435 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
436 RB_CLEAR_NODE(&mr->r_rb_node);
437 zot_me = 1;
438 }
439 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
440
441 /* May have to issue a dma_sync on this memory region.
442 * Note we could avoid this if the operation was a RDMA READ,
443 * but at this point we can't tell. */
444 if (mr->r_trans->sync_mr)
445 mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
446
447 /* If the MR was marked as invalidate, this will
448 * trigger an async flush. */
449 if (zot_me) {
450 rds_destroy_mr(mr);
451 rds_mr_put(mr);
452 }
453 }
454
rds_rdma_free_op(struct rm_rdma_op * ro)455 void rds_rdma_free_op(struct rm_rdma_op *ro)
456 {
457 unsigned int i;
458
459 for (i = 0; i < ro->op_nents; i++) {
460 struct page *page = sg_page(&ro->op_sg[i]);
461
462 /* Mark page dirty if it was possibly modified, which
463 * is the case for a RDMA_READ which copies from remote
464 * to local memory */
465 if (!ro->op_write) {
466 WARN_ON(!page->mapping && irqs_disabled());
467 set_page_dirty(page);
468 }
469 put_page(page);
470 }
471
472 kfree(ro->op_notifier);
473 ro->op_notifier = NULL;
474 ro->op_active = 0;
475 }
476
rds_atomic_free_op(struct rm_atomic_op * ao)477 void rds_atomic_free_op(struct rm_atomic_op *ao)
478 {
479 struct page *page = sg_page(ao->op_sg);
480
481 /* Mark page dirty if it was possibly modified, which
482 * is the case for a RDMA_READ which copies from remote
483 * to local memory */
484 set_page_dirty(page);
485 put_page(page);
486
487 kfree(ao->op_notifier);
488 ao->op_notifier = NULL;
489 ao->op_active = 0;
490 }
491
492
493 /*
494 * Count the number of pages needed to describe an incoming iovec array.
495 */
rds_rdma_pages(struct rds_iovec iov[],int nr_iovecs)496 static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
497 {
498 int tot_pages = 0;
499 unsigned int nr_pages;
500 unsigned int i;
501
502 /* figure out the number of pages in the vector */
503 for (i = 0; i < nr_iovecs; i++) {
504 nr_pages = rds_pages_in_vec(&iov[i]);
505 if (nr_pages == 0)
506 return -EINVAL;
507
508 tot_pages += nr_pages;
509
510 /*
511 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
512 * so tot_pages cannot overflow without first going negative.
513 */
514 if (tot_pages < 0)
515 return -EINVAL;
516 }
517
518 return tot_pages;
519 }
520
rds_rdma_extra_size(struct rds_rdma_args * args,struct rds_iov_vector * iov)521 int rds_rdma_extra_size(struct rds_rdma_args *args,
522 struct rds_iov_vector *iov)
523 {
524 struct rds_iovec *vec;
525 struct rds_iovec __user *local_vec;
526 int tot_pages = 0;
527 unsigned int nr_pages;
528 unsigned int i;
529
530 local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
531
532 if (args->nr_local == 0)
533 return -EINVAL;
534
535 iov->iov = kcalloc(args->nr_local,
536 sizeof(struct rds_iovec),
537 GFP_KERNEL);
538 if (!iov->iov)
539 return -ENOMEM;
540
541 vec = &iov->iov[0];
542
543 if (copy_from_user(vec, local_vec, args->nr_local *
544 sizeof(struct rds_iovec)))
545 return -EFAULT;
546 iov->len = args->nr_local;
547
548 /* figure out the number of pages in the vector */
549 for (i = 0; i < args->nr_local; i++, vec++) {
550
551 nr_pages = rds_pages_in_vec(vec);
552 if (nr_pages == 0)
553 return -EINVAL;
554
555 tot_pages += nr_pages;
556
557 /*
558 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
559 * so tot_pages cannot overflow without first going negative.
560 */
561 if (tot_pages < 0)
562 return -EINVAL;
563 }
564
565 return tot_pages * sizeof(struct scatterlist);
566 }
567
568 /*
569 * The application asks for a RDMA transfer.
570 * Extract all arguments and set up the rdma_op
571 */
rds_cmsg_rdma_args(struct rds_sock * rs,struct rds_message * rm,struct cmsghdr * cmsg,struct rds_iov_vector * vec)572 int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
573 struct cmsghdr *cmsg,
574 struct rds_iov_vector *vec)
575 {
576 struct rds_rdma_args *args;
577 struct rm_rdma_op *op = &rm->rdma;
578 int nr_pages;
579 unsigned int nr_bytes;
580 struct page **pages = NULL;
581 struct rds_iovec *iovs;
582 unsigned int i, j;
583 int ret = 0;
584
585 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args))
586 || rm->rdma.op_active)
587 return -EINVAL;
588
589 args = CMSG_DATA(cmsg);
590
591 if (ipv6_addr_any(&rs->rs_bound_addr)) {
592 ret = -ENOTCONN; /* XXX not a great errno */
593 goto out_ret;
594 }
595
596 if (args->nr_local > UIO_MAXIOV) {
597 ret = -EMSGSIZE;
598 goto out_ret;
599 }
600
601 if (vec->len != args->nr_local) {
602 ret = -EINVAL;
603 goto out_ret;
604 }
605
606 iovs = vec->iov;
607
608 nr_pages = rds_rdma_pages(iovs, args->nr_local);
609 if (nr_pages < 0) {
610 ret = -EINVAL;
611 goto out_ret;
612 }
613
614 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
615 if (!pages) {
616 ret = -ENOMEM;
617 goto out_ret;
618 }
619
620 op->op_write = !!(args->flags & RDS_RDMA_READWRITE);
621 op->op_fence = !!(args->flags & RDS_RDMA_FENCE);
622 op->op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
623 op->op_silent = !!(args->flags & RDS_RDMA_SILENT);
624 op->op_active = 1;
625 op->op_recverr = rs->rs_recverr;
626 WARN_ON(!nr_pages);
627 op->op_sg = rds_message_alloc_sgs(rm, nr_pages, &ret);
628 if (!op->op_sg)
629 goto out_pages;
630
631 if (op->op_notify || op->op_recverr) {
632 /* We allocate an uninitialized notifier here, because
633 * we don't want to do that in the completion handler. We
634 * would have to use GFP_ATOMIC there, and don't want to deal
635 * with failed allocations.
636 */
637 op->op_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL);
638 if (!op->op_notifier) {
639 ret = -ENOMEM;
640 goto out_pages;
641 }
642 op->op_notifier->n_user_token = args->user_token;
643 op->op_notifier->n_status = RDS_RDMA_SUCCESS;
644 }
645
646 /* The cookie contains the R_Key of the remote memory region, and
647 * optionally an offset into it. This is how we implement RDMA into
648 * unaligned memory.
649 * When setting up the RDMA, we need to add that offset to the
650 * destination address (which is really an offset into the MR)
651 * FIXME: We may want to move this into ib_rdma.c
652 */
653 op->op_rkey = rds_rdma_cookie_key(args->cookie);
654 op->op_remote_addr = args->remote_vec.addr + rds_rdma_cookie_offset(args->cookie);
655
656 nr_bytes = 0;
657
658 rdsdebug("RDS: rdma prepare nr_local %llu rva %llx rkey %x\n",
659 (unsigned long long)args->nr_local,
660 (unsigned long long)args->remote_vec.addr,
661 op->op_rkey);
662
663 for (i = 0; i < args->nr_local; i++) {
664 struct rds_iovec *iov = &iovs[i];
665 /* don't need to check, rds_rdma_pages() verified nr will be +nonzero */
666 unsigned int nr = rds_pages_in_vec(iov);
667
668 rs->rs_user_addr = iov->addr;
669 rs->rs_user_bytes = iov->bytes;
670
671 /* If it's a WRITE operation, we want to pin the pages for reading.
672 * If it's a READ operation, we need to pin the pages for writing.
673 */
674 ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write);
675 if (ret < 0)
676 goto out_pages;
677 else
678 ret = 0;
679
680 rdsdebug("RDS: nr_bytes %u nr %u iov->bytes %llu iov->addr %llx\n",
681 nr_bytes, nr, iov->bytes, iov->addr);
682
683 nr_bytes += iov->bytes;
684
685 for (j = 0; j < nr; j++) {
686 unsigned int offset = iov->addr & ~PAGE_MASK;
687 struct scatterlist *sg;
688
689 sg = &op->op_sg[op->op_nents + j];
690 sg_set_page(sg, pages[j],
691 min_t(unsigned int, iov->bytes, PAGE_SIZE - offset),
692 offset);
693
694 rdsdebug("RDS: sg->offset %x sg->len %x iov->addr %llx iov->bytes %llu\n",
695 sg->offset, sg->length, iov->addr, iov->bytes);
696
697 iov->addr += sg->length;
698 iov->bytes -= sg->length;
699 }
700
701 op->op_nents += nr;
702 }
703
704 if (nr_bytes > args->remote_vec.bytes) {
705 rdsdebug("RDS nr_bytes %u remote_bytes %u do not match\n",
706 nr_bytes,
707 (unsigned int) args->remote_vec.bytes);
708 ret = -EINVAL;
709 goto out_pages;
710 }
711 op->op_bytes = nr_bytes;
712
713 out_pages:
714 kfree(pages);
715 out_ret:
716 if (ret)
717 rds_rdma_free_op(op);
718 else
719 rds_stats_inc(s_send_rdma);
720
721 return ret;
722 }
723
724 /*
725 * The application wants us to pass an RDMA destination (aka MR)
726 * to the remote
727 */
rds_cmsg_rdma_dest(struct rds_sock * rs,struct rds_message * rm,struct cmsghdr * cmsg)728 int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
729 struct cmsghdr *cmsg)
730 {
731 unsigned long flags;
732 struct rds_mr *mr;
733 u32 r_key;
734 int err = 0;
735
736 if (cmsg->cmsg_len < CMSG_LEN(sizeof(rds_rdma_cookie_t)) ||
737 rm->m_rdma_cookie != 0)
738 return -EINVAL;
739
740 memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg), sizeof(rm->m_rdma_cookie));
741
742 /* We are reusing a previously mapped MR here. Most likely, the
743 * application has written to the buffer, so we need to explicitly
744 * flush those writes to RAM. Otherwise the HCA may not see them
745 * when doing a DMA from that buffer.
746 */
747 r_key = rds_rdma_cookie_key(rm->m_rdma_cookie);
748
749 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
750 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
751 if (!mr)
752 err = -EINVAL; /* invalid r_key */
753 else
754 refcount_inc(&mr->r_refcount);
755 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
756
757 if (mr) {
758 mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
759 rm->rdma.op_rdma_mr = mr;
760 }
761 return err;
762 }
763
764 /*
765 * The application passes us an address range it wants to enable RDMA
766 * to/from. We map the area, and save the <R_Key,offset> pair
767 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
768 * in an extension header.
769 */
rds_cmsg_rdma_map(struct rds_sock * rs,struct rds_message * rm,struct cmsghdr * cmsg)770 int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
771 struct cmsghdr *cmsg)
772 {
773 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_get_mr_args)) ||
774 rm->m_rdma_cookie != 0)
775 return -EINVAL;
776
777 return __rds_rdma_map(rs, CMSG_DATA(cmsg), &rm->m_rdma_cookie,
778 &rm->rdma.op_rdma_mr, rm->m_conn_path);
779 }
780
781 /*
782 * Fill in rds_message for an atomic request.
783 */
rds_cmsg_atomic(struct rds_sock * rs,struct rds_message * rm,struct cmsghdr * cmsg)784 int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
785 struct cmsghdr *cmsg)
786 {
787 struct page *page = NULL;
788 struct rds_atomic_args *args;
789 int ret = 0;
790
791 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_atomic_args))
792 || rm->atomic.op_active)
793 return -EINVAL;
794
795 args = CMSG_DATA(cmsg);
796
797 /* Nonmasked & masked cmsg ops converted to masked hw ops */
798 switch (cmsg->cmsg_type) {
799 case RDS_CMSG_ATOMIC_FADD:
800 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
801 rm->atomic.op_m_fadd.add = args->fadd.add;
802 rm->atomic.op_m_fadd.nocarry_mask = 0;
803 break;
804 case RDS_CMSG_MASKED_ATOMIC_FADD:
805 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
806 rm->atomic.op_m_fadd.add = args->m_fadd.add;
807 rm->atomic.op_m_fadd.nocarry_mask = args->m_fadd.nocarry_mask;
808 break;
809 case RDS_CMSG_ATOMIC_CSWP:
810 rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
811 rm->atomic.op_m_cswp.compare = args->cswp.compare;
812 rm->atomic.op_m_cswp.swap = args->cswp.swap;
813 rm->atomic.op_m_cswp.compare_mask = ~0;
814 rm->atomic.op_m_cswp.swap_mask = ~0;
815 break;
816 case RDS_CMSG_MASKED_ATOMIC_CSWP:
817 rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
818 rm->atomic.op_m_cswp.compare = args->m_cswp.compare;
819 rm->atomic.op_m_cswp.swap = args->m_cswp.swap;
820 rm->atomic.op_m_cswp.compare_mask = args->m_cswp.compare_mask;
821 rm->atomic.op_m_cswp.swap_mask = args->m_cswp.swap_mask;
822 break;
823 default:
824 BUG(); /* should never happen */
825 }
826
827 rm->atomic.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
828 rm->atomic.op_silent = !!(args->flags & RDS_RDMA_SILENT);
829 rm->atomic.op_active = 1;
830 rm->atomic.op_recverr = rs->rs_recverr;
831 rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1, &ret);
832 if (!rm->atomic.op_sg)
833 goto err;
834
835 /* verify 8 byte-aligned */
836 if (args->local_addr & 0x7) {
837 ret = -EFAULT;
838 goto err;
839 }
840
841 ret = rds_pin_pages(args->local_addr, 1, &page, 1);
842 if (ret != 1)
843 goto err;
844 ret = 0;
845
846 sg_set_page(rm->atomic.op_sg, page, 8, offset_in_page(args->local_addr));
847
848 if (rm->atomic.op_notify || rm->atomic.op_recverr) {
849 /* We allocate an uninitialized notifier here, because
850 * we don't want to do that in the completion handler. We
851 * would have to use GFP_ATOMIC there, and don't want to deal
852 * with failed allocations.
853 */
854 rm->atomic.op_notifier = kmalloc(sizeof(*rm->atomic.op_notifier), GFP_KERNEL);
855 if (!rm->atomic.op_notifier) {
856 ret = -ENOMEM;
857 goto err;
858 }
859
860 rm->atomic.op_notifier->n_user_token = args->user_token;
861 rm->atomic.op_notifier->n_status = RDS_RDMA_SUCCESS;
862 }
863
864 rm->atomic.op_rkey = rds_rdma_cookie_key(args->cookie);
865 rm->atomic.op_remote_addr = args->remote_addr + rds_rdma_cookie_offset(args->cookie);
866
867 return ret;
868 err:
869 if (page)
870 put_page(page);
871 rm->atomic.op_active = 0;
872 kfree(rm->atomic.op_notifier);
873
874 return ret;
875 }
876