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1/*
2 * Copyright (c) 2007, 2020 Oracle and/or its affiliates.
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 */
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 kref_get(&insert->r_kref);
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, kref_read(&mr->r_kref));
103
104 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
105 if (!RB_EMPTY_NODE(&mr->r_rb_node))
106 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
107 trans_private = mr->r_trans_private;
108 mr->r_trans_private = NULL;
109 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
110
111 if (trans_private)
112 mr->r_trans->free_mr(trans_private, mr->r_invalidate);
113}
114
115void __rds_put_mr_final(struct kref *kref)
116{
117 struct rds_mr *mr = container_of(kref, struct rds_mr, r_kref);
118
119 rds_destroy_mr(mr);
120 kfree(mr);
121}
122
123/*
124 * By the time this is called we can't have any more ioctls called on
125 * the socket so we don't need to worry about racing with others.
126 */
127void rds_rdma_drop_keys(struct rds_sock *rs)
128{
129 struct rds_mr *mr;
130 struct rb_node *node;
131 unsigned long flags;
132
133 /* Release any MRs associated with this socket */
134 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
135 while ((node = rb_first(&rs->rs_rdma_keys))) {
136 mr = rb_entry(node, struct rds_mr, r_rb_node);
137 if (mr->r_trans == rs->rs_transport)
138 mr->r_invalidate = 0;
139 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
140 RB_CLEAR_NODE(&mr->r_rb_node);
141 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
142 kref_put(&mr->r_kref, __rds_put_mr_final);
143 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
144 }
145 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
146
147 if (rs->rs_transport && rs->rs_transport->flush_mrs)
148 rs->rs_transport->flush_mrs();
149}
150
151/*
152 * Helper function to pin user pages.
153 */
154static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages,
155 struct page **pages, int write)
156{
157 unsigned int gup_flags = FOLL_LONGTERM;
158 int ret;
159
160 if (write)
161 gup_flags |= FOLL_WRITE;
162
163 ret = pin_user_pages_fast(user_addr, nr_pages, gup_flags, pages);
164 if (ret >= 0 && ret < nr_pages) {
165 unpin_user_pages(pages, ret);
166 ret = -EFAULT;
167 }
168
169 return ret;
170}
171
172static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
173 u64 *cookie_ret, struct rds_mr **mr_ret,
174 struct rds_conn_path *cp)
175{
176 struct rds_mr *mr = NULL, *found;
177 struct scatterlist *sg = NULL;
178 unsigned int nr_pages;
179 struct page **pages = NULL;
180 void *trans_private;
181 unsigned long flags;
182 rds_rdma_cookie_t cookie;
183 unsigned int nents = 0;
184 int need_odp = 0;
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 /* If the combination of the addr and size requested for this memory
199 * region causes an integer overflow, return error.
200 */
201 if (((args->vec.addr + args->vec.bytes) < args->vec.addr) ||
202 PAGE_ALIGN(args->vec.addr + args->vec.bytes) <
203 (args->vec.addr + args->vec.bytes)) {
204 ret = -EINVAL;
205 goto out;
206 }
207
208 if (!can_do_mlock()) {
209 ret = -EPERM;
210 goto out;
211 }
212
213 nr_pages = rds_pages_in_vec(&args->vec);
214 if (nr_pages == 0) {
215 ret = -EINVAL;
216 goto out;
217 }
218
219 /* Restrict the size of mr irrespective of underlying transport
220 * To account for unaligned mr regions, subtract one from nr_pages
221 */
222 if ((nr_pages - 1) > (RDS_MAX_MSG_SIZE >> PAGE_SHIFT)) {
223 ret = -EMSGSIZE;
224 goto out;
225 }
226
227 rdsdebug("RDS: get_mr addr %llx len %llu nr_pages %u\n",
228 args->vec.addr, args->vec.bytes, nr_pages);
229
230 /* XXX clamp nr_pages to limit the size of this alloc? */
231 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
232 if (!pages) {
233 ret = -ENOMEM;
234 goto out;
235 }
236
237 mr = kzalloc(sizeof(struct rds_mr), GFP_KERNEL);
238 if (!mr) {
239 ret = -ENOMEM;
240 goto out;
241 }
242
243 kref_init(&mr->r_kref);
244 RB_CLEAR_NODE(&mr->r_rb_node);
245 mr->r_trans = rs->rs_transport;
246 mr->r_sock = rs;
247
248 if (args->flags & RDS_RDMA_USE_ONCE)
249 mr->r_use_once = 1;
250 if (args->flags & RDS_RDMA_INVALIDATE)
251 mr->r_invalidate = 1;
252 if (args->flags & RDS_RDMA_READWRITE)
253 mr->r_write = 1;
254
255 /*
256 * Pin the pages that make up the user buffer and transfer the page
257 * pointers to the mr's sg array. We check to see if we've mapped
258 * the whole region after transferring the partial page references
259 * to the sg array so that we can have one page ref cleanup path.
260 *
261 * For now we have no flag that tells us whether the mapping is
262 * r/o or r/w. We need to assume r/w, or we'll do a lot of RDMA to
263 * the zero page.
264 */
265 ret = rds_pin_pages(args->vec.addr, nr_pages, pages, 1);
266 if (ret == -EOPNOTSUPP) {
267 need_odp = 1;
268 } else if (ret <= 0) {
269 goto out;
270 } else {
271 nents = ret;
272 sg = kmalloc_array(nents, sizeof(*sg), GFP_KERNEL);
273 if (!sg) {
274 ret = -ENOMEM;
275 goto out;
276 }
277 WARN_ON(!nents);
278 sg_init_table(sg, nents);
279
280 /* Stick all pages into the scatterlist */
281 for (i = 0 ; i < nents; i++)
282 sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0);
283
284 rdsdebug("RDS: trans_private nents is %u\n", nents);
285 }
286 /* Obtain a transport specific MR. If this succeeds, the
287 * s/g list is now owned by the MR.
288 * Note that dma_map() implies that pending writes are
289 * flushed to RAM, so no dma_sync is needed here. */
290 trans_private = rs->rs_transport->get_mr(
291 sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL,
292 args->vec.addr, args->vec.bytes,
293 need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);
294
295 if (IS_ERR(trans_private)) {
296 /* In ODP case, we don't GUP pages, so don't need
297 * to release anything.
298 */
299 if (!need_odp) {
300 unpin_user_pages(pages, nr_pages);
301 kfree(sg);
302 }
303 ret = PTR_ERR(trans_private);
304 /* Trigger connection so that its ready for the next retry */
305 if (ret == -ENODEV && cp)
306 rds_conn_connect_if_down(cp->cp_conn);
307 goto out;
308 }
309
310 mr->r_trans_private = trans_private;
311
312 rdsdebug("RDS: get_mr put_user key is %x cookie_addr %p\n",
313 mr->r_key, (void *)(unsigned long) args->cookie_addr);
314
315 /* The user may pass us an unaligned address, but we can only
316 * map page aligned regions. So we keep the offset, and build
317 * a 64bit cookie containing <R_Key, offset> and pass that
318 * around. */
319 if (need_odp)
320 cookie = rds_rdma_make_cookie(mr->r_key, 0);
321 else
322 cookie = rds_rdma_make_cookie(mr->r_key,
323 args->vec.addr & ~PAGE_MASK);
324 if (cookie_ret)
325 *cookie_ret = cookie;
326
327 if (args->cookie_addr &&
328 put_user(cookie, (u64 __user *)(unsigned long)args->cookie_addr)) {
329 if (!need_odp) {
330 unpin_user_pages(pages, nr_pages);
331 kfree(sg);
332 }
333 ret = -EFAULT;
334 goto out;
335 }
336
337 /* Inserting the new MR into the rbtree bumps its
338 * reference count. */
339 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
340 found = rds_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
341 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
342
343 BUG_ON(found && found != mr);
344
345 rdsdebug("RDS: get_mr key is %x\n", mr->r_key);
346 if (mr_ret) {
347 kref_get(&mr->r_kref);
348 *mr_ret = mr;
349 }
350
351 ret = 0;
352out:
353 kfree(pages);
354 if (mr)
355 kref_put(&mr->r_kref, __rds_put_mr_final);
356 return ret;
357}
358
359int rds_get_mr(struct rds_sock *rs, sockptr_t optval, int optlen)
360{
361 struct rds_get_mr_args args;
362
363 if (optlen != sizeof(struct rds_get_mr_args))
364 return -EINVAL;
365
366 if (copy_from_sockptr(&args, optval, sizeof(struct rds_get_mr_args)))
367 return -EFAULT;
368
369 return __rds_rdma_map(rs, &args, NULL, NULL, NULL);
370}
371
372int rds_get_mr_for_dest(struct rds_sock *rs, sockptr_t optval, int optlen)
373{
374 struct rds_get_mr_for_dest_args args;
375 struct rds_get_mr_args new_args;
376
377 if (optlen != sizeof(struct rds_get_mr_for_dest_args))
378 return -EINVAL;
379
380 if (copy_from_sockptr(&args, optval,
381 sizeof(struct rds_get_mr_for_dest_args)))
382 return -EFAULT;
383
384 /*
385 * Initially, just behave like get_mr().
386 * TODO: Implement get_mr as wrapper around this
387 * and deprecate it.
388 */
389 new_args.vec = args.vec;
390 new_args.cookie_addr = args.cookie_addr;
391 new_args.flags = args.flags;
392
393 return __rds_rdma_map(rs, &new_args, NULL, NULL, NULL);
394}
395
396/*
397 * Free the MR indicated by the given R_Key
398 */
399int rds_free_mr(struct rds_sock *rs, sockptr_t optval, int optlen)
400{
401 struct rds_free_mr_args args;
402 struct rds_mr *mr;
403 unsigned long flags;
404
405 if (optlen != sizeof(struct rds_free_mr_args))
406 return -EINVAL;
407
408 if (copy_from_sockptr(&args, optval, sizeof(struct rds_free_mr_args)))
409 return -EFAULT;
410
411 /* Special case - a null cookie means flush all unused MRs */
412 if (args.cookie == 0) {
413 if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
414 return -EINVAL;
415 rs->rs_transport->flush_mrs();
416 return 0;
417 }
418
419 /* Look up the MR given its R_key and remove it from the rbtree
420 * so nobody else finds it.
421 * This should also prevent races with rds_rdma_unuse.
422 */
423 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
424 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, rds_rdma_cookie_key(args.cookie), NULL);
425 if (mr) {
426 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
427 RB_CLEAR_NODE(&mr->r_rb_node);
428 if (args.flags & RDS_RDMA_INVALIDATE)
429 mr->r_invalidate = 1;
430 }
431 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
432
433 if (!mr)
434 return -EINVAL;
435
436 kref_put(&mr->r_kref, __rds_put_mr_final);
437 return 0;
438}
439
440/*
441 * This is called when we receive an extension header that
442 * tells us this MR was used. It allows us to implement
443 * use_once semantics
444 */
445void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force)
446{
447 struct rds_mr *mr;
448 unsigned long flags;
449 int zot_me = 0;
450
451 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
452 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
453 if (!mr) {
454 pr_debug("rds: trying to unuse MR with unknown r_key %u!\n",
455 r_key);
456 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
457 return;
458 }
459
460 /* Get a reference so that the MR won't go away before calling
461 * sync_mr() below.
462 */
463 kref_get(&mr->r_kref);
464
465 /* If it is going to be freed, remove it from the tree now so
466 * that no other thread can find it and free it.
467 */
468 if (mr->r_use_once || force) {
469 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
470 RB_CLEAR_NODE(&mr->r_rb_node);
471 zot_me = 1;
472 }
473 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
474
475 /* May have to issue a dma_sync on this memory region.
476 * Note we could avoid this if the operation was a RDMA READ,
477 * but at this point we can't tell. */
478 if (mr->r_trans->sync_mr)
479 mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
480
481 /* Release the reference held above. */
482 kref_put(&mr->r_kref, __rds_put_mr_final);
483
484 /* If the MR was marked as invalidate, this will
485 * trigger an async flush. */
486 if (zot_me)
487 kref_put(&mr->r_kref, __rds_put_mr_final);
488}
489
490void rds_rdma_free_op(struct rm_rdma_op *ro)
491{
492 unsigned int i;
493
494 if (ro->op_odp_mr) {
495 kref_put(&ro->op_odp_mr->r_kref, __rds_put_mr_final);
496 } else {
497 for (i = 0; i < ro->op_nents; i++) {
498 struct page *page = sg_page(&ro->op_sg[i]);
499
500 /* Mark page dirty if it was possibly modified, which
501 * is the case for a RDMA_READ which copies from remote
502 * to local memory
503 */
504 unpin_user_pages_dirty_lock(&page, 1, !ro->op_write);
505 }
506 }
507
508 kfree(ro->op_notifier);
509 ro->op_notifier = NULL;
510 ro->op_active = 0;
511 ro->op_odp_mr = NULL;
512}
513
514void rds_atomic_free_op(struct rm_atomic_op *ao)
515{
516 struct page *page = sg_page(ao->op_sg);
517
518 /* Mark page dirty if it was possibly modified, which
519 * is the case for a RDMA_READ which copies from remote
520 * to local memory */
521 unpin_user_pages_dirty_lock(&page, 1, true);
522
523 kfree(ao->op_notifier);
524 ao->op_notifier = NULL;
525 ao->op_active = 0;
526}
527
528
529/*
530 * Count the number of pages needed to describe an incoming iovec array.
531 */
532static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
533{
534 int tot_pages = 0;
535 unsigned int nr_pages;
536 unsigned int i;
537
538 /* figure out the number of pages in the vector */
539 for (i = 0; i < nr_iovecs; i++) {
540 nr_pages = rds_pages_in_vec(&iov[i]);
541 if (nr_pages == 0)
542 return -EINVAL;
543
544 tot_pages += nr_pages;
545
546 /*
547 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
548 * so tot_pages cannot overflow without first going negative.
549 */
550 if (tot_pages < 0)
551 return -EINVAL;
552 }
553
554 return tot_pages;
555}
556
557int rds_rdma_extra_size(struct rds_rdma_args *args,
558 struct rds_iov_vector *iov)
559{
560 struct rds_iovec *vec;
561 struct rds_iovec __user *local_vec;
562 int tot_pages = 0;
563 unsigned int nr_pages;
564 unsigned int i;
565
566 local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
567
568 if (args->nr_local == 0)
569 return -EINVAL;
570
571 if (args->nr_local > UIO_MAXIOV)
572 return -EMSGSIZE;
573
574 iov->iov = kcalloc(args->nr_local,
575 sizeof(struct rds_iovec),
576 GFP_KERNEL);
577 if (!iov->iov)
578 return -ENOMEM;
579
580 vec = &iov->iov[0];
581
582 if (copy_from_user(vec, local_vec, args->nr_local *
583 sizeof(struct rds_iovec)))
584 return -EFAULT;
585 iov->len = args->nr_local;
586
587 /* figure out the number of pages in the vector */
588 for (i = 0; i < args->nr_local; i++, vec++) {
589
590 nr_pages = rds_pages_in_vec(vec);
591 if (nr_pages == 0)
592 return -EINVAL;
593
594 tot_pages += nr_pages;
595
596 /*
597 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
598 * so tot_pages cannot overflow without first going negative.
599 */
600 if (tot_pages < 0)
601 return -EINVAL;
602 }
603
604 return tot_pages * sizeof(struct scatterlist);
605}
606
607/*
608 * The application asks for a RDMA transfer.
609 * Extract all arguments and set up the rdma_op
610 */
611int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
612 struct cmsghdr *cmsg,
613 struct rds_iov_vector *vec)
614{
615 struct rds_rdma_args *args;
616 struct rm_rdma_op *op = &rm->rdma;
617 int nr_pages;
618 unsigned int nr_bytes;
619 struct page **pages = NULL;
620 struct rds_iovec *iovs;
621 unsigned int i, j;
622 int ret = 0;
623 bool odp_supported = true;
624
625 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args))
626 || rm->rdma.op_active)
627 return -EINVAL;
628
629 args = CMSG_DATA(cmsg);
630
631 if (ipv6_addr_any(&rs->rs_bound_addr)) {
632 ret = -ENOTCONN; /* XXX not a great errno */
633 goto out_ret;
634 }
635
636 if (args->nr_local > UIO_MAXIOV) {
637 ret = -EMSGSIZE;
638 goto out_ret;
639 }
640
641 if (vec->len != args->nr_local) {
642 ret = -EINVAL;
643 goto out_ret;
644 }
645 /* odp-mr is not supported for multiple requests within one message */
646 if (args->nr_local != 1)
647 odp_supported = false;
648
649 iovs = vec->iov;
650
651 nr_pages = rds_rdma_pages(iovs, args->nr_local);
652 if (nr_pages < 0) {
653 ret = -EINVAL;
654 goto out_ret;
655 }
656
657 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
658 if (!pages) {
659 ret = -ENOMEM;
660 goto out_ret;
661 }
662
663 op->op_write = !!(args->flags & RDS_RDMA_READWRITE);
664 op->op_fence = !!(args->flags & RDS_RDMA_FENCE);
665 op->op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
666 op->op_silent = !!(args->flags & RDS_RDMA_SILENT);
667 op->op_active = 1;
668 op->op_recverr = rs->rs_recverr;
669 op->op_odp_mr = NULL;
670
671 WARN_ON(!nr_pages);
672 op->op_sg = rds_message_alloc_sgs(rm, nr_pages);
673 if (IS_ERR(op->op_sg)) {
674 ret = PTR_ERR(op->op_sg);
675 goto out_pages;
676 }
677
678 if (op->op_notify || op->op_recverr) {
679 /* We allocate an uninitialized notifier here, because
680 * we don't want to do that in the completion handler. We
681 * would have to use GFP_ATOMIC there, and don't want to deal
682 * with failed allocations.
683 */
684 op->op_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL);
685 if (!op->op_notifier) {
686 ret = -ENOMEM;
687 goto out_pages;
688 }
689 op->op_notifier->n_user_token = args->user_token;
690 op->op_notifier->n_status = RDS_RDMA_SUCCESS;
691 }
692
693 /* The cookie contains the R_Key of the remote memory region, and
694 * optionally an offset into it. This is how we implement RDMA into
695 * unaligned memory.
696 * When setting up the RDMA, we need to add that offset to the
697 * destination address (which is really an offset into the MR)
698 * FIXME: We may want to move this into ib_rdma.c
699 */
700 op->op_rkey = rds_rdma_cookie_key(args->cookie);
701 op->op_remote_addr = args->remote_vec.addr + rds_rdma_cookie_offset(args->cookie);
702
703 nr_bytes = 0;
704
705 rdsdebug("RDS: rdma prepare nr_local %llu rva %llx rkey %x\n",
706 (unsigned long long)args->nr_local,
707 (unsigned long long)args->remote_vec.addr,
708 op->op_rkey);
709
710 for (i = 0; i < args->nr_local; i++) {
711 struct rds_iovec *iov = &iovs[i];
712 /* don't need to check, rds_rdma_pages() verified nr will be +nonzero */
713 unsigned int nr = rds_pages_in_vec(iov);
714
715 rs->rs_user_addr = iov->addr;
716 rs->rs_user_bytes = iov->bytes;
717
718 /* If it's a WRITE operation, we want to pin the pages for reading.
719 * If it's a READ operation, we need to pin the pages for writing.
720 */
721 ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write);
722 if ((!odp_supported && ret <= 0) ||
723 (odp_supported && ret <= 0 && ret != -EOPNOTSUPP))
724 goto out_pages;
725
726 if (ret == -EOPNOTSUPP) {
727 struct rds_mr *local_odp_mr;
728
729 if (!rs->rs_transport->get_mr) {
730 ret = -EOPNOTSUPP;
731 goto out_pages;
732 }
733 local_odp_mr =
734 kzalloc(sizeof(*local_odp_mr), GFP_KERNEL);
735 if (!local_odp_mr) {
736 ret = -ENOMEM;
737 goto out_pages;
738 }
739 RB_CLEAR_NODE(&local_odp_mr->r_rb_node);
740 kref_init(&local_odp_mr->r_kref);
741 local_odp_mr->r_trans = rs->rs_transport;
742 local_odp_mr->r_sock = rs;
743 local_odp_mr->r_trans_private =
744 rs->rs_transport->get_mr(
745 NULL, 0, rs, &local_odp_mr->r_key, NULL,
746 iov->addr, iov->bytes, ODP_VIRTUAL);
747 if (IS_ERR(local_odp_mr->r_trans_private)) {
748 ret = PTR_ERR(local_odp_mr->r_trans_private);
749 rdsdebug("get_mr ret %d %p\"", ret,
750 local_odp_mr->r_trans_private);
751 kfree(local_odp_mr);
752 ret = -EOPNOTSUPP;
753 goto out_pages;
754 }
755 rdsdebug("Need odp; local_odp_mr %p trans_private %p\n",
756 local_odp_mr, local_odp_mr->r_trans_private);
757 op->op_odp_mr = local_odp_mr;
758 op->op_odp_addr = iov->addr;
759 }
760
761 rdsdebug("RDS: nr_bytes %u nr %u iov->bytes %llu iov->addr %llx\n",
762 nr_bytes, nr, iov->bytes, iov->addr);
763
764 nr_bytes += iov->bytes;
765
766 for (j = 0; j < nr; j++) {
767 unsigned int offset = iov->addr & ~PAGE_MASK;
768 struct scatterlist *sg;
769
770 sg = &op->op_sg[op->op_nents + j];
771 sg_set_page(sg, pages[j],
772 min_t(unsigned int, iov->bytes, PAGE_SIZE - offset),
773 offset);
774
775 sg_dma_len(sg) = sg->length;
776 rdsdebug("RDS: sg->offset %x sg->len %x iov->addr %llx iov->bytes %llu\n",
777 sg->offset, sg->length, iov->addr, iov->bytes);
778
779 iov->addr += sg->length;
780 iov->bytes -= sg->length;
781 }
782
783 op->op_nents += nr;
784 }
785
786 if (nr_bytes > args->remote_vec.bytes) {
787 rdsdebug("RDS nr_bytes %u remote_bytes %u do not match\n",
788 nr_bytes,
789 (unsigned int) args->remote_vec.bytes);
790 ret = -EINVAL;
791 goto out_pages;
792 }
793 op->op_bytes = nr_bytes;
794 ret = 0;
795
796out_pages:
797 kfree(pages);
798out_ret:
799 if (ret)
800 rds_rdma_free_op(op);
801 else
802 rds_stats_inc(s_send_rdma);
803
804 return ret;
805}
806
807/*
808 * The application wants us to pass an RDMA destination (aka MR)
809 * to the remote
810 */
811int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
812 struct cmsghdr *cmsg)
813{
814 unsigned long flags;
815 struct rds_mr *mr;
816 u32 r_key;
817 int err = 0;
818
819 if (cmsg->cmsg_len < CMSG_LEN(sizeof(rds_rdma_cookie_t)) ||
820 rm->m_rdma_cookie != 0)
821 return -EINVAL;
822
823 memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg), sizeof(rm->m_rdma_cookie));
824
825 /* We are reusing a previously mapped MR here. Most likely, the
826 * application has written to the buffer, so we need to explicitly
827 * flush those writes to RAM. Otherwise the HCA may not see them
828 * when doing a DMA from that buffer.
829 */
830 r_key = rds_rdma_cookie_key(rm->m_rdma_cookie);
831
832 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
833 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
834 if (!mr)
835 err = -EINVAL; /* invalid r_key */
836 else
837 kref_get(&mr->r_kref);
838 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
839
840 if (mr) {
841 mr->r_trans->sync_mr(mr->r_trans_private,
842 DMA_TO_DEVICE);
843 rm->rdma.op_rdma_mr = mr;
844 }
845 return err;
846}
847
848/*
849 * The application passes us an address range it wants to enable RDMA
850 * to/from. We map the area, and save the <R_Key,offset> pair
851 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
852 * in an extension header.
853 */
854int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
855 struct cmsghdr *cmsg)
856{
857 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_get_mr_args)) ||
858 rm->m_rdma_cookie != 0)
859 return -EINVAL;
860
861 return __rds_rdma_map(rs, CMSG_DATA(cmsg), &rm->m_rdma_cookie,
862 &rm->rdma.op_rdma_mr, rm->m_conn_path);
863}
864
865/*
866 * Fill in rds_message for an atomic request.
867 */
868int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
869 struct cmsghdr *cmsg)
870{
871 struct page *page = NULL;
872 struct rds_atomic_args *args;
873 int ret = 0;
874
875 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_atomic_args))
876 || rm->atomic.op_active)
877 return -EINVAL;
878
879 args = CMSG_DATA(cmsg);
880
881 /* Nonmasked & masked cmsg ops converted to masked hw ops */
882 switch (cmsg->cmsg_type) {
883 case RDS_CMSG_ATOMIC_FADD:
884 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
885 rm->atomic.op_m_fadd.add = args->fadd.add;
886 rm->atomic.op_m_fadd.nocarry_mask = 0;
887 break;
888 case RDS_CMSG_MASKED_ATOMIC_FADD:
889 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
890 rm->atomic.op_m_fadd.add = args->m_fadd.add;
891 rm->atomic.op_m_fadd.nocarry_mask = args->m_fadd.nocarry_mask;
892 break;
893 case RDS_CMSG_ATOMIC_CSWP:
894 rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
895 rm->atomic.op_m_cswp.compare = args->cswp.compare;
896 rm->atomic.op_m_cswp.swap = args->cswp.swap;
897 rm->atomic.op_m_cswp.compare_mask = ~0;
898 rm->atomic.op_m_cswp.swap_mask = ~0;
899 break;
900 case RDS_CMSG_MASKED_ATOMIC_CSWP:
901 rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
902 rm->atomic.op_m_cswp.compare = args->m_cswp.compare;
903 rm->atomic.op_m_cswp.swap = args->m_cswp.swap;
904 rm->atomic.op_m_cswp.compare_mask = args->m_cswp.compare_mask;
905 rm->atomic.op_m_cswp.swap_mask = args->m_cswp.swap_mask;
906 break;
907 default:
908 BUG(); /* should never happen */
909 }
910
911 rm->atomic.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
912 rm->atomic.op_silent = !!(args->flags & RDS_RDMA_SILENT);
913 rm->atomic.op_active = 1;
914 rm->atomic.op_recverr = rs->rs_recverr;
915 rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1);
916 if (IS_ERR(rm->atomic.op_sg)) {
917 ret = PTR_ERR(rm->atomic.op_sg);
918 goto err;
919 }
920
921 /* verify 8 byte-aligned */
922 if (args->local_addr & 0x7) {
923 ret = -EFAULT;
924 goto err;
925 }
926
927 ret = rds_pin_pages(args->local_addr, 1, &page, 1);
928 if (ret != 1)
929 goto err;
930 ret = 0;
931
932 sg_set_page(rm->atomic.op_sg, page, 8, offset_in_page(args->local_addr));
933
934 if (rm->atomic.op_notify || rm->atomic.op_recverr) {
935 /* We allocate an uninitialized notifier here, because
936 * we don't want to do that in the completion handler. We
937 * would have to use GFP_ATOMIC there, and don't want to deal
938 * with failed allocations.
939 */
940 rm->atomic.op_notifier = kmalloc(sizeof(*rm->atomic.op_notifier), GFP_KERNEL);
941 if (!rm->atomic.op_notifier) {
942 ret = -ENOMEM;
943 goto err;
944 }
945
946 rm->atomic.op_notifier->n_user_token = args->user_token;
947 rm->atomic.op_notifier->n_status = RDS_RDMA_SUCCESS;
948 }
949
950 rm->atomic.op_rkey = rds_rdma_cookie_key(args->cookie);
951 rm->atomic.op_remote_addr = args->remote_addr + rds_rdma_cookie_offset(args->cookie);
952
953 return ret;
954err:
955 if (page)
956 unpin_user_page(page);
957 rm->atomic.op_active = 0;
958 kfree(rm->atomic.op_notifier);
959
960 return ret;
961}
1/*
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/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 */
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 refcount_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, 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
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 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 */
156static 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, pages);
162
163 if (ret >= 0 && ret < nr_pages) {
164 while (ret--)
165 put_page(pages[ret]);
166 ret = -EFAULT;
167 }
168
169 return ret;
170}
171
172static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
173 u64 *cookie_ret, struct rds_mr **mr_ret)
174{
175 struct rds_mr *mr = NULL, *found;
176 unsigned int nr_pages;
177 struct page **pages = NULL;
178 struct scatterlist *sg;
179 void *trans_private;
180 unsigned long flags;
181 rds_rdma_cookie_t cookie;
182 unsigned int nents;
183 long i;
184 int ret;
185
186 if (rs->rs_bound_addr == 0 || !rs->rs_transport) {
187 ret = -ENOTCONN; /* XXX not a great errno */
188 goto out;
189 }
190
191 if (!rs->rs_transport->get_mr) {
192 ret = -EOPNOTSUPP;
193 goto out;
194 }
195
196 nr_pages = rds_pages_in_vec(&args->vec);
197 if (nr_pages == 0) {
198 ret = -EINVAL;
199 goto out;
200 }
201
202 /* Restrict the size of mr irrespective of underlying transport
203 * To account for unaligned mr regions, subtract one from nr_pages
204 */
205 if ((nr_pages - 1) > (RDS_MAX_MSG_SIZE >> PAGE_SHIFT)) {
206 ret = -EMSGSIZE;
207 goto out;
208 }
209
210 rdsdebug("RDS: get_mr addr %llx len %llu nr_pages %u\n",
211 args->vec.addr, args->vec.bytes, nr_pages);
212
213 /* XXX clamp nr_pages to limit the size of this alloc? */
214 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
215 if (!pages) {
216 ret = -ENOMEM;
217 goto out;
218 }
219
220 mr = kzalloc(sizeof(struct rds_mr), GFP_KERNEL);
221 if (!mr) {
222 ret = -ENOMEM;
223 goto out;
224 }
225
226 refcount_set(&mr->r_refcount, 1);
227 RB_CLEAR_NODE(&mr->r_rb_node);
228 mr->r_trans = rs->rs_transport;
229 mr->r_sock = rs;
230
231 if (args->flags & RDS_RDMA_USE_ONCE)
232 mr->r_use_once = 1;
233 if (args->flags & RDS_RDMA_INVALIDATE)
234 mr->r_invalidate = 1;
235 if (args->flags & RDS_RDMA_READWRITE)
236 mr->r_write = 1;
237
238 /*
239 * Pin the pages that make up the user buffer and transfer the page
240 * pointers to the mr's sg array. We check to see if we've mapped
241 * the whole region after transferring the partial page references
242 * to the sg array so that we can have one page ref cleanup path.
243 *
244 * For now we have no flag that tells us whether the mapping is
245 * r/o or r/w. We need to assume r/w, or we'll do a lot of RDMA to
246 * the zero page.
247 */
248 ret = rds_pin_pages(args->vec.addr, nr_pages, pages, 1);
249 if (ret < 0)
250 goto out;
251
252 nents = ret;
253 sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL);
254 if (!sg) {
255 ret = -ENOMEM;
256 goto out;
257 }
258 WARN_ON(!nents);
259 sg_init_table(sg, nents);
260
261 /* Stick all pages into the scatterlist */
262 for (i = 0 ; i < nents; i++)
263 sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0);
264
265 rdsdebug("RDS: trans_private nents is %u\n", nents);
266
267 /* Obtain a transport specific MR. If this succeeds, the
268 * s/g list is now owned by the MR.
269 * Note that dma_map() implies that pending writes are
270 * flushed to RAM, so no dma_sync is needed here. */
271 trans_private = rs->rs_transport->get_mr(sg, nents, rs,
272 &mr->r_key);
273
274 if (IS_ERR(trans_private)) {
275 for (i = 0 ; i < nents; i++)
276 put_page(sg_page(&sg[i]));
277 kfree(sg);
278 ret = PTR_ERR(trans_private);
279 goto out;
280 }
281
282 mr->r_trans_private = trans_private;
283
284 rdsdebug("RDS: get_mr put_user key is %x cookie_addr %p\n",
285 mr->r_key, (void *)(unsigned long) args->cookie_addr);
286
287 /* The user may pass us an unaligned address, but we can only
288 * map page aligned regions. So we keep the offset, and build
289 * a 64bit cookie containing <R_Key, offset> and pass that
290 * around. */
291 cookie = rds_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGE_MASK);
292 if (cookie_ret)
293 *cookie_ret = cookie;
294
295 if (args->cookie_addr && put_user(cookie, (u64 __user *)(unsigned long) args->cookie_addr)) {
296 ret = -EFAULT;
297 goto out;
298 }
299
300 /* Inserting the new MR into the rbtree bumps its
301 * reference count. */
302 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
303 found = rds_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr);
304 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
305
306 BUG_ON(found && found != mr);
307
308 rdsdebug("RDS: get_mr key is %x\n", mr->r_key);
309 if (mr_ret) {
310 refcount_inc(&mr->r_refcount);
311 *mr_ret = mr;
312 }
313
314 ret = 0;
315out:
316 kfree(pages);
317 if (mr)
318 rds_mr_put(mr);
319 return ret;
320}
321
322int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen)
323{
324 struct rds_get_mr_args args;
325
326 if (optlen != sizeof(struct rds_get_mr_args))
327 return -EINVAL;
328
329 if (copy_from_user(&args, (struct rds_get_mr_args __user *)optval,
330 sizeof(struct rds_get_mr_args)))
331 return -EFAULT;
332
333 return __rds_rdma_map(rs, &args, NULL, NULL);
334}
335
336int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen)
337{
338 struct rds_get_mr_for_dest_args args;
339 struct rds_get_mr_args new_args;
340
341 if (optlen != sizeof(struct rds_get_mr_for_dest_args))
342 return -EINVAL;
343
344 if (copy_from_user(&args, (struct rds_get_mr_for_dest_args __user *)optval,
345 sizeof(struct rds_get_mr_for_dest_args)))
346 return -EFAULT;
347
348 /*
349 * Initially, just behave like get_mr().
350 * TODO: Implement get_mr as wrapper around this
351 * and deprecate it.
352 */
353 new_args.vec = args.vec;
354 new_args.cookie_addr = args.cookie_addr;
355 new_args.flags = args.flags;
356
357 return __rds_rdma_map(rs, &new_args, NULL, NULL);
358}
359
360/*
361 * Free the MR indicated by the given R_Key
362 */
363int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen)
364{
365 struct rds_free_mr_args args;
366 struct rds_mr *mr;
367 unsigned long flags;
368
369 if (optlen != sizeof(struct rds_free_mr_args))
370 return -EINVAL;
371
372 if (copy_from_user(&args, (struct rds_free_mr_args __user *)optval,
373 sizeof(struct rds_free_mr_args)))
374 return -EFAULT;
375
376 /* Special case - a null cookie means flush all unused MRs */
377 if (args.cookie == 0) {
378 if (!rs->rs_transport || !rs->rs_transport->flush_mrs)
379 return -EINVAL;
380 rs->rs_transport->flush_mrs();
381 return 0;
382 }
383
384 /* Look up the MR given its R_key and remove it from the rbtree
385 * so nobody else finds it.
386 * This should also prevent races with rds_rdma_unuse.
387 */
388 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
389 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, rds_rdma_cookie_key(args.cookie), NULL);
390 if (mr) {
391 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
392 RB_CLEAR_NODE(&mr->r_rb_node);
393 if (args.flags & RDS_RDMA_INVALIDATE)
394 mr->r_invalidate = 1;
395 }
396 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
397
398 if (!mr)
399 return -EINVAL;
400
401 /*
402 * call rds_destroy_mr() ourselves so that we're sure it's done by the time
403 * we return. If we let rds_mr_put() do it it might not happen until
404 * someone else drops their ref.
405 */
406 rds_destroy_mr(mr);
407 rds_mr_put(mr);
408 return 0;
409}
410
411/*
412 * This is called when we receive an extension header that
413 * tells us this MR was used. It allows us to implement
414 * use_once semantics
415 */
416void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force)
417{
418 struct rds_mr *mr;
419 unsigned long flags;
420 int zot_me = 0;
421
422 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
423 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
424 if (!mr) {
425 pr_debug("rds: trying to unuse MR with unknown r_key %u!\n",
426 r_key);
427 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
428 return;
429 }
430
431 if (mr->r_use_once || force) {
432 rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
433 RB_CLEAR_NODE(&mr->r_rb_node);
434 zot_me = 1;
435 }
436 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
437
438 /* May have to issue a dma_sync on this memory region.
439 * Note we could avoid this if the operation was a RDMA READ,
440 * but at this point we can't tell. */
441 if (mr->r_trans->sync_mr)
442 mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
443
444 /* If the MR was marked as invalidate, this will
445 * trigger an async flush. */
446 if (zot_me) {
447 rds_destroy_mr(mr);
448 rds_mr_put(mr);
449 }
450}
451
452void rds_rdma_free_op(struct rm_rdma_op *ro)
453{
454 unsigned int i;
455
456 for (i = 0; i < ro->op_nents; i++) {
457 struct page *page = sg_page(&ro->op_sg[i]);
458
459 /* Mark page dirty if it was possibly modified, which
460 * is the case for a RDMA_READ which copies from remote
461 * to local memory */
462 if (!ro->op_write) {
463 WARN_ON(!page->mapping && irqs_disabled());
464 set_page_dirty(page);
465 }
466 put_page(page);
467 }
468
469 kfree(ro->op_notifier);
470 ro->op_notifier = NULL;
471 ro->op_active = 0;
472}
473
474void rds_atomic_free_op(struct rm_atomic_op *ao)
475{
476 struct page *page = sg_page(ao->op_sg);
477
478 /* Mark page dirty if it was possibly modified, which
479 * is the case for a RDMA_READ which copies from remote
480 * to local memory */
481 set_page_dirty(page);
482 put_page(page);
483
484 kfree(ao->op_notifier);
485 ao->op_notifier = NULL;
486 ao->op_active = 0;
487}
488
489
490/*
491 * Count the number of pages needed to describe an incoming iovec array.
492 */
493static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
494{
495 int tot_pages = 0;
496 unsigned int nr_pages;
497 unsigned int i;
498
499 /* figure out the number of pages in the vector */
500 for (i = 0; i < nr_iovecs; i++) {
501 nr_pages = rds_pages_in_vec(&iov[i]);
502 if (nr_pages == 0)
503 return -EINVAL;
504
505 tot_pages += nr_pages;
506
507 /*
508 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
509 * so tot_pages cannot overflow without first going negative.
510 */
511 if (tot_pages < 0)
512 return -EINVAL;
513 }
514
515 return tot_pages;
516}
517
518int rds_rdma_extra_size(struct rds_rdma_args *args)
519{
520 struct rds_iovec vec;
521 struct rds_iovec __user *local_vec;
522 int tot_pages = 0;
523 unsigned int nr_pages;
524 unsigned int i;
525
526 local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr;
527
528 if (args->nr_local == 0)
529 return -EINVAL;
530
531 /* figure out the number of pages in the vector */
532 for (i = 0; i < args->nr_local; i++) {
533 if (copy_from_user(&vec, &local_vec[i],
534 sizeof(struct rds_iovec)))
535 return -EFAULT;
536
537 nr_pages = rds_pages_in_vec(&vec);
538 if (nr_pages == 0)
539 return -EINVAL;
540
541 tot_pages += nr_pages;
542
543 /*
544 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
545 * so tot_pages cannot overflow without first going negative.
546 */
547 if (tot_pages < 0)
548 return -EINVAL;
549 }
550
551 return tot_pages * sizeof(struct scatterlist);
552}
553
554/*
555 * The application asks for a RDMA transfer.
556 * Extract all arguments and set up the rdma_op
557 */
558int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
559 struct cmsghdr *cmsg)
560{
561 struct rds_rdma_args *args;
562 struct rm_rdma_op *op = &rm->rdma;
563 int nr_pages;
564 unsigned int nr_bytes;
565 struct page **pages = NULL;
566 struct rds_iovec iovstack[UIO_FASTIOV], *iovs = iovstack;
567 int iov_size;
568 unsigned int i, j;
569 int ret = 0;
570
571 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args))
572 || rm->rdma.op_active)
573 return -EINVAL;
574
575 args = CMSG_DATA(cmsg);
576
577 if (rs->rs_bound_addr == 0) {
578 ret = -ENOTCONN; /* XXX not a great errno */
579 goto out_ret;
580 }
581
582 if (args->nr_local > UIO_MAXIOV) {
583 ret = -EMSGSIZE;
584 goto out_ret;
585 }
586
587 /* Check whether to allocate the iovec area */
588 iov_size = args->nr_local * sizeof(struct rds_iovec);
589 if (args->nr_local > UIO_FASTIOV) {
590 iovs = sock_kmalloc(rds_rs_to_sk(rs), iov_size, GFP_KERNEL);
591 if (!iovs) {
592 ret = -ENOMEM;
593 goto out_ret;
594 }
595 }
596
597 if (copy_from_user(iovs, (struct rds_iovec __user *)(unsigned long) args->local_vec_addr, iov_size)) {
598 ret = -EFAULT;
599 goto out;
600 }
601
602 nr_pages = rds_rdma_pages(iovs, args->nr_local);
603 if (nr_pages < 0) {
604 ret = -EINVAL;
605 goto out;
606 }
607
608 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
609 if (!pages) {
610 ret = -ENOMEM;
611 goto out;
612 }
613
614 op->op_write = !!(args->flags & RDS_RDMA_READWRITE);
615 op->op_fence = !!(args->flags & RDS_RDMA_FENCE);
616 op->op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
617 op->op_silent = !!(args->flags & RDS_RDMA_SILENT);
618 op->op_active = 1;
619 op->op_recverr = rs->rs_recverr;
620 WARN_ON(!nr_pages);
621 op->op_sg = rds_message_alloc_sgs(rm, nr_pages);
622 if (!op->op_sg) {
623 ret = -ENOMEM;
624 goto out;
625 }
626
627 if (op->op_notify || op->op_recverr) {
628 /* We allocate an uninitialized notifier here, because
629 * we don't want to do that in the completion handler. We
630 * would have to use GFP_ATOMIC there, and don't want to deal
631 * with failed allocations.
632 */
633 op->op_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL);
634 if (!op->op_notifier) {
635 ret = -ENOMEM;
636 goto out;
637 }
638 op->op_notifier->n_user_token = args->user_token;
639 op->op_notifier->n_status = RDS_RDMA_SUCCESS;
640
641 /* Enable rmda notification on data operation for composite
642 * rds messages and make sure notification is enabled only
643 * for the data operation which follows it so that application
644 * gets notified only after full message gets delivered.
645 */
646 if (rm->data.op_sg) {
647 rm->rdma.op_notify = 0;
648 rm->data.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
649 }
650 }
651
652 /* The cookie contains the R_Key of the remote memory region, and
653 * optionally an offset into it. This is how we implement RDMA into
654 * unaligned memory.
655 * When setting up the RDMA, we need to add that offset to the
656 * destination address (which is really an offset into the MR)
657 * FIXME: We may want to move this into ib_rdma.c
658 */
659 op->op_rkey = rds_rdma_cookie_key(args->cookie);
660 op->op_remote_addr = args->remote_vec.addr + rds_rdma_cookie_offset(args->cookie);
661
662 nr_bytes = 0;
663
664 rdsdebug("RDS: rdma prepare nr_local %llu rva %llx rkey %x\n",
665 (unsigned long long)args->nr_local,
666 (unsigned long long)args->remote_vec.addr,
667 op->op_rkey);
668
669 for (i = 0; i < args->nr_local; i++) {
670 struct rds_iovec *iov = &iovs[i];
671 /* don't need to check, rds_rdma_pages() verified nr will be +nonzero */
672 unsigned int nr = rds_pages_in_vec(iov);
673
674 rs->rs_user_addr = iov->addr;
675 rs->rs_user_bytes = iov->bytes;
676
677 /* If it's a WRITE operation, we want to pin the pages for reading.
678 * If it's a READ operation, we need to pin the pages for writing.
679 */
680 ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write);
681 if (ret < 0)
682 goto out;
683 else
684 ret = 0;
685
686 rdsdebug("RDS: nr_bytes %u nr %u iov->bytes %llu iov->addr %llx\n",
687 nr_bytes, nr, iov->bytes, iov->addr);
688
689 nr_bytes += iov->bytes;
690
691 for (j = 0; j < nr; j++) {
692 unsigned int offset = iov->addr & ~PAGE_MASK;
693 struct scatterlist *sg;
694
695 sg = &op->op_sg[op->op_nents + j];
696 sg_set_page(sg, pages[j],
697 min_t(unsigned int, iov->bytes, PAGE_SIZE - offset),
698 offset);
699
700 rdsdebug("RDS: sg->offset %x sg->len %x iov->addr %llx iov->bytes %llu\n",
701 sg->offset, sg->length, iov->addr, iov->bytes);
702
703 iov->addr += sg->length;
704 iov->bytes -= sg->length;
705 }
706
707 op->op_nents += nr;
708 }
709
710 if (nr_bytes > args->remote_vec.bytes) {
711 rdsdebug("RDS nr_bytes %u remote_bytes %u do not match\n",
712 nr_bytes,
713 (unsigned int) args->remote_vec.bytes);
714 ret = -EINVAL;
715 goto out;
716 }
717 op->op_bytes = nr_bytes;
718
719out:
720 if (iovs != iovstack)
721 sock_kfree_s(rds_rs_to_sk(rs), iovs, iov_size);
722 kfree(pages);
723out_ret:
724 if (ret)
725 rds_rdma_free_op(op);
726 else
727 rds_stats_inc(s_send_rdma);
728
729 return ret;
730}
731
732/*
733 * The application wants us to pass an RDMA destination (aka MR)
734 * to the remote
735 */
736int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
737 struct cmsghdr *cmsg)
738{
739 unsigned long flags;
740 struct rds_mr *mr;
741 u32 r_key;
742 int err = 0;
743
744 if (cmsg->cmsg_len < CMSG_LEN(sizeof(rds_rdma_cookie_t)) ||
745 rm->m_rdma_cookie != 0)
746 return -EINVAL;
747
748 memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg), sizeof(rm->m_rdma_cookie));
749
750 /* We are reusing a previously mapped MR here. Most likely, the
751 * application has written to the buffer, so we need to explicitly
752 * flush those writes to RAM. Otherwise the HCA may not see them
753 * when doing a DMA from that buffer.
754 */
755 r_key = rds_rdma_cookie_key(rm->m_rdma_cookie);
756
757 spin_lock_irqsave(&rs->rs_rdma_lock, flags);
758 mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
759 if (!mr)
760 err = -EINVAL; /* invalid r_key */
761 else
762 refcount_inc(&mr->r_refcount);
763 spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
764
765 if (mr) {
766 mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE);
767 rm->rdma.op_rdma_mr = mr;
768 }
769 return err;
770}
771
772/*
773 * The application passes us an address range it wants to enable RDMA
774 * to/from. We map the area, and save the <R_Key,offset> pair
775 * in rm->m_rdma_cookie. This causes it to be sent along to the peer
776 * in an extension header.
777 */
778int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
779 struct cmsghdr *cmsg)
780{
781 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_get_mr_args)) ||
782 rm->m_rdma_cookie != 0)
783 return -EINVAL;
784
785 return __rds_rdma_map(rs, CMSG_DATA(cmsg), &rm->m_rdma_cookie, &rm->rdma.op_rdma_mr);
786}
787
788/*
789 * Fill in rds_message for an atomic request.
790 */
791int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
792 struct cmsghdr *cmsg)
793{
794 struct page *page = NULL;
795 struct rds_atomic_args *args;
796 int ret = 0;
797
798 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_atomic_args))
799 || rm->atomic.op_active)
800 return -EINVAL;
801
802 args = CMSG_DATA(cmsg);
803
804 /* Nonmasked & masked cmsg ops converted to masked hw ops */
805 switch (cmsg->cmsg_type) {
806 case RDS_CMSG_ATOMIC_FADD:
807 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
808 rm->atomic.op_m_fadd.add = args->fadd.add;
809 rm->atomic.op_m_fadd.nocarry_mask = 0;
810 break;
811 case RDS_CMSG_MASKED_ATOMIC_FADD:
812 rm->atomic.op_type = RDS_ATOMIC_TYPE_FADD;
813 rm->atomic.op_m_fadd.add = args->m_fadd.add;
814 rm->atomic.op_m_fadd.nocarry_mask = args->m_fadd.nocarry_mask;
815 break;
816 case RDS_CMSG_ATOMIC_CSWP:
817 rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
818 rm->atomic.op_m_cswp.compare = args->cswp.compare;
819 rm->atomic.op_m_cswp.swap = args->cswp.swap;
820 rm->atomic.op_m_cswp.compare_mask = ~0;
821 rm->atomic.op_m_cswp.swap_mask = ~0;
822 break;
823 case RDS_CMSG_MASKED_ATOMIC_CSWP:
824 rm->atomic.op_type = RDS_ATOMIC_TYPE_CSWP;
825 rm->atomic.op_m_cswp.compare = args->m_cswp.compare;
826 rm->atomic.op_m_cswp.swap = args->m_cswp.swap;
827 rm->atomic.op_m_cswp.compare_mask = args->m_cswp.compare_mask;
828 rm->atomic.op_m_cswp.swap_mask = args->m_cswp.swap_mask;
829 break;
830 default:
831 BUG(); /* should never happen */
832 }
833
834 rm->atomic.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME);
835 rm->atomic.op_silent = !!(args->flags & RDS_RDMA_SILENT);
836 rm->atomic.op_active = 1;
837 rm->atomic.op_recverr = rs->rs_recverr;
838 rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1);
839 if (!rm->atomic.op_sg) {
840 ret = -ENOMEM;
841 goto err;
842 }
843
844 /* verify 8 byte-aligned */
845 if (args->local_addr & 0x7) {
846 ret = -EFAULT;
847 goto err;
848 }
849
850 ret = rds_pin_pages(args->local_addr, 1, &page, 1);
851 if (ret != 1)
852 goto err;
853 ret = 0;
854
855 sg_set_page(rm->atomic.op_sg, page, 8, offset_in_page(args->local_addr));
856
857 if (rm->atomic.op_notify || rm->atomic.op_recverr) {
858 /* We allocate an uninitialized notifier here, because
859 * we don't want to do that in the completion handler. We
860 * would have to use GFP_ATOMIC there, and don't want to deal
861 * with failed allocations.
862 */
863 rm->atomic.op_notifier = kmalloc(sizeof(*rm->atomic.op_notifier), GFP_KERNEL);
864 if (!rm->atomic.op_notifier) {
865 ret = -ENOMEM;
866 goto err;
867 }
868
869 rm->atomic.op_notifier->n_user_token = args->user_token;
870 rm->atomic.op_notifier->n_status = RDS_RDMA_SUCCESS;
871 }
872
873 rm->atomic.op_rkey = rds_rdma_cookie_key(args->cookie);
874 rm->atomic.op_remote_addr = args->remote_addr + rds_rdma_cookie_offset(args->cookie);
875
876 return ret;
877err:
878 if (page)
879 put_page(page);
880 rm->atomic.op_active = 0;
881 kfree(rm->atomic.op_notifier);
882
883 return ret;
884}