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eff5f53b AG |
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/rbtree.h> | |
35 | #include <linux/dma-mapping.h> /* for DMA_*_DEVICE */ | |
36 | ||
37 | #include "rdma.h" | |
38 | ||
39 | /* | |
40 | * XXX | |
41 | * - build with sparse | |
42 | * - should we limit the size of a mr region? let transport return failure? | |
43 | * - should we detect duplicate keys on a socket? hmm. | |
44 | * - an rdma is an mlock, apply rlimit? | |
45 | */ | |
46 | ||
47 | /* | |
48 | * get the number of pages by looking at the page indices that the start and | |
49 | * end addresses fall in. | |
50 | * | |
51 | * Returns 0 if the vec is invalid. It is invalid if the number of bytes | |
52 | * causes the address to wrap or overflows an unsigned int. This comes | |
53 | * from being stored in the 'length' member of 'struct scatterlist'. | |
54 | */ | |
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 | ||
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 | atomic_inc(&insert->r_refcount); | |
88 | } | |
89 | return NULL; | |
90 | } | |
91 | ||
92 | /* | |
93 | * Destroy the transport-specific part of a MR. | |
94 | */ | |
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, atomic_read(&mr->r_refcount)); | |
103 | ||
104 | if (test_and_set_bit(RDS_MR_DEAD, &mr->r_state)) | |
105 | return; | |
106 | ||
107 | spin_lock_irqsave(&rs->rs_rdma_lock, flags); | |
108 | if (!RB_EMPTY_NODE(&mr->r_rb_node)) | |
109 | rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys); | |
110 | trans_private = mr->r_trans_private; | |
111 | mr->r_trans_private = NULL; | |
112 | spin_unlock_irqrestore(&rs->rs_rdma_lock, flags); | |
113 | ||
114 | if (trans_private) | |
115 | mr->r_trans->free_mr(trans_private, mr->r_invalidate); | |
116 | } | |
117 | ||
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 | */ | |
128 | void rds_rdma_drop_keys(struct rds_sock *rs) | |
129 | { | |
130 | struct rds_mr *mr; | |
131 | struct rb_node *node; | |
132 | ||
133 | /* Release any MRs associated with this socket */ | |
134 | while ((node = rb_first(&rs->rs_rdma_keys))) { | |
135 | mr = container_of(node, struct rds_mr, r_rb_node); | |
136 | if (mr->r_trans == rs->rs_transport) | |
137 | mr->r_invalidate = 0; | |
138 | rds_mr_put(mr); | |
139 | } | |
140 | ||
141 | if (rs->rs_transport && rs->rs_transport->flush_mrs) | |
142 | rs->rs_transport->flush_mrs(); | |
143 | } | |
144 | ||
145 | /* | |
146 | * Helper function to pin user pages. | |
147 | */ | |
148 | static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages, | |
149 | struct page **pages, int write) | |
150 | { | |
151 | int ret; | |
152 | ||
153 | down_read(¤t->mm->mmap_sem); | |
154 | ret = get_user_pages(current, current->mm, user_addr, | |
155 | nr_pages, write, 0, pages, NULL); | |
156 | up_read(¤t->mm->mmap_sem); | |
157 | ||
7acd4a79 | 158 | if (ret >= 0 && ret < nr_pages) { |
eff5f53b AG |
159 | while (ret--) |
160 | put_page(pages[ret]); | |
161 | ret = -EFAULT; | |
162 | } | |
163 | ||
164 | return ret; | |
165 | } | |
166 | ||
167 | static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args, | |
168 | u64 *cookie_ret, struct rds_mr **mr_ret) | |
169 | { | |
170 | struct rds_mr *mr = NULL, *found; | |
171 | unsigned int nr_pages; | |
172 | struct page **pages = NULL; | |
173 | struct scatterlist *sg; | |
174 | void *trans_private; | |
175 | unsigned long flags; | |
176 | rds_rdma_cookie_t cookie; | |
177 | unsigned int nents; | |
178 | long i; | |
179 | int ret; | |
180 | ||
181 | if (rs->rs_bound_addr == 0) { | |
182 | ret = -ENOTCONN; /* XXX not a great errno */ | |
183 | goto out; | |
184 | } | |
185 | ||
186 | if (rs->rs_transport->get_mr == NULL) { | |
187 | ret = -EOPNOTSUPP; | |
188 | goto out; | |
189 | } | |
190 | ||
191 | nr_pages = rds_pages_in_vec(&args->vec); | |
192 | if (nr_pages == 0) { | |
193 | ret = -EINVAL; | |
194 | goto out; | |
195 | } | |
196 | ||
197 | rdsdebug("RDS: get_mr addr %llx len %llu nr_pages %u\n", | |
198 | args->vec.addr, args->vec.bytes, nr_pages); | |
199 | ||
200 | /* XXX clamp nr_pages to limit the size of this alloc? */ | |
201 | pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL); | |
202 | if (pages == NULL) { | |
203 | ret = -ENOMEM; | |
204 | goto out; | |
205 | } | |
206 | ||
207 | mr = kzalloc(sizeof(struct rds_mr), GFP_KERNEL); | |
208 | if (mr == NULL) { | |
209 | ret = -ENOMEM; | |
210 | goto out; | |
211 | } | |
212 | ||
213 | atomic_set(&mr->r_refcount, 1); | |
214 | RB_CLEAR_NODE(&mr->r_rb_node); | |
215 | mr->r_trans = rs->rs_transport; | |
216 | mr->r_sock = rs; | |
217 | ||
218 | if (args->flags & RDS_RDMA_USE_ONCE) | |
219 | mr->r_use_once = 1; | |
220 | if (args->flags & RDS_RDMA_INVALIDATE) | |
221 | mr->r_invalidate = 1; | |
222 | if (args->flags & RDS_RDMA_READWRITE) | |
223 | mr->r_write = 1; | |
224 | ||
225 | /* | |
226 | * Pin the pages that make up the user buffer and transfer the page | |
227 | * pointers to the mr's sg array. We check to see if we've mapped | |
228 | * the whole region after transferring the partial page references | |
229 | * to the sg array so that we can have one page ref cleanup path. | |
230 | * | |
231 | * For now we have no flag that tells us whether the mapping is | |
232 | * r/o or r/w. We need to assume r/w, or we'll do a lot of RDMA to | |
233 | * the zero page. | |
234 | */ | |
235 | ret = rds_pin_pages(args->vec.addr & PAGE_MASK, nr_pages, pages, 1); | |
236 | if (ret < 0) | |
237 | goto out; | |
238 | ||
239 | nents = ret; | |
240 | sg = kcalloc(nents, sizeof(*sg), GFP_KERNEL); | |
241 | if (sg == NULL) { | |
242 | ret = -ENOMEM; | |
243 | goto out; | |
244 | } | |
245 | WARN_ON(!nents); | |
246 | sg_init_table(sg, nents); | |
247 | ||
248 | /* Stick all pages into the scatterlist */ | |
249 | for (i = 0 ; i < nents; i++) | |
250 | sg_set_page(&sg[i], pages[i], PAGE_SIZE, 0); | |
251 | ||
252 | rdsdebug("RDS: trans_private nents is %u\n", nents); | |
253 | ||
254 | /* Obtain a transport specific MR. If this succeeds, the | |
255 | * s/g list is now owned by the MR. | |
256 | * Note that dma_map() implies that pending writes are | |
257 | * flushed to RAM, so no dma_sync is needed here. */ | |
258 | trans_private = rs->rs_transport->get_mr(sg, nents, rs, | |
259 | &mr->r_key); | |
260 | ||
261 | if (IS_ERR(trans_private)) { | |
262 | for (i = 0 ; i < nents; i++) | |
263 | put_page(sg_page(&sg[i])); | |
264 | kfree(sg); | |
265 | ret = PTR_ERR(trans_private); | |
266 | goto out; | |
267 | } | |
268 | ||
269 | mr->r_trans_private = trans_private; | |
270 | ||
271 | rdsdebug("RDS: get_mr put_user key is %x cookie_addr %p\n", | |
272 | mr->r_key, (void *)(unsigned long) args->cookie_addr); | |
273 | ||
274 | /* The user may pass us an unaligned address, but we can only | |
275 | * map page aligned regions. So we keep the offset, and build | |
276 | * a 64bit cookie containing <R_Key, offset> and pass that | |
277 | * around. */ | |
278 | cookie = rds_rdma_make_cookie(mr->r_key, args->vec.addr & ~PAGE_MASK); | |
279 | if (cookie_ret) | |
280 | *cookie_ret = cookie; | |
281 | ||
282 | if (args->cookie_addr && put_user(cookie, (u64 __user *)(unsigned long) args->cookie_addr)) { | |
283 | ret = -EFAULT; | |
284 | goto out; | |
285 | } | |
286 | ||
287 | /* Inserting the new MR into the rbtree bumps its | |
288 | * reference count. */ | |
289 | spin_lock_irqsave(&rs->rs_rdma_lock, flags); | |
290 | found = rds_mr_tree_walk(&rs->rs_rdma_keys, mr->r_key, mr); | |
291 | spin_unlock_irqrestore(&rs->rs_rdma_lock, flags); | |
292 | ||
293 | BUG_ON(found && found != mr); | |
294 | ||
295 | rdsdebug("RDS: get_mr key is %x\n", mr->r_key); | |
296 | if (mr_ret) { | |
297 | atomic_inc(&mr->r_refcount); | |
298 | *mr_ret = mr; | |
299 | } | |
300 | ||
301 | ret = 0; | |
302 | out: | |
303 | kfree(pages); | |
304 | if (mr) | |
305 | rds_mr_put(mr); | |
306 | return ret; | |
307 | } | |
308 | ||
309 | int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen) | |
310 | { | |
311 | struct rds_get_mr_args args; | |
312 | ||
313 | if (optlen != sizeof(struct rds_get_mr_args)) | |
314 | return -EINVAL; | |
315 | ||
316 | if (copy_from_user(&args, (struct rds_get_mr_args __user *)optval, | |
317 | sizeof(struct rds_get_mr_args))) | |
318 | return -EFAULT; | |
319 | ||
320 | return __rds_rdma_map(rs, &args, NULL, NULL); | |
321 | } | |
322 | ||
323 | /* | |
324 | * Free the MR indicated by the given R_Key | |
325 | */ | |
326 | int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen) | |
327 | { | |
328 | struct rds_free_mr_args args; | |
329 | struct rds_mr *mr; | |
330 | unsigned long flags; | |
331 | ||
332 | if (optlen != sizeof(struct rds_free_mr_args)) | |
333 | return -EINVAL; | |
334 | ||
335 | if (copy_from_user(&args, (struct rds_free_mr_args __user *)optval, | |
336 | sizeof(struct rds_free_mr_args))) | |
337 | return -EFAULT; | |
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 | /* Look up the MR given its R_key and remove it from the rbtree | |
348 | * so nobody else finds it. | |
349 | * This should also prevent races with rds_rdma_unuse. | |
350 | */ | |
351 | spin_lock_irqsave(&rs->rs_rdma_lock, flags); | |
352 | mr = rds_mr_tree_walk(&rs->rs_rdma_keys, rds_rdma_cookie_key(args.cookie), NULL); | |
353 | if (mr) { | |
354 | rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys); | |
355 | RB_CLEAR_NODE(&mr->r_rb_node); | |
356 | if (args.flags & RDS_RDMA_INVALIDATE) | |
357 | mr->r_invalidate = 1; | |
358 | } | |
359 | spin_unlock_irqrestore(&rs->rs_rdma_lock, flags); | |
360 | ||
361 | if (!mr) | |
362 | return -EINVAL; | |
363 | ||
364 | /* | |
365 | * call rds_destroy_mr() ourselves so that we're sure it's done by the time | |
366 | * we return. If we let rds_mr_put() do it it might not happen until | |
367 | * someone else drops their ref. | |
368 | */ | |
369 | rds_destroy_mr(mr); | |
370 | rds_mr_put(mr); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | /* | |
375 | * This is called when we receive an extension header that | |
376 | * tells us this MR was used. It allows us to implement | |
377 | * use_once semantics | |
378 | */ | |
379 | void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force) | |
380 | { | |
381 | struct rds_mr *mr; | |
382 | unsigned long flags; | |
383 | int zot_me = 0; | |
384 | ||
385 | spin_lock_irqsave(&rs->rs_rdma_lock, flags); | |
386 | mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL); | |
387 | if (mr && (mr->r_use_once || force)) { | |
388 | rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys); | |
389 | RB_CLEAR_NODE(&mr->r_rb_node); | |
390 | zot_me = 1; | |
391 | } else if (mr) | |
392 | atomic_inc(&mr->r_refcount); | |
393 | spin_unlock_irqrestore(&rs->rs_rdma_lock, flags); | |
394 | ||
395 | /* May have to issue a dma_sync on this memory region. | |
396 | * Note we could avoid this if the operation was a RDMA READ, | |
397 | * but at this point we can't tell. */ | |
398 | if (mr != NULL) { | |
399 | if (mr->r_trans->sync_mr) | |
400 | mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE); | |
401 | ||
402 | /* If the MR was marked as invalidate, this will | |
403 | * trigger an async flush. */ | |
404 | if (zot_me) | |
405 | rds_destroy_mr(mr); | |
406 | rds_mr_put(mr); | |
407 | } | |
408 | } | |
409 | ||
410 | void rds_rdma_free_op(struct rds_rdma_op *ro) | |
411 | { | |
412 | unsigned int i; | |
413 | ||
414 | for (i = 0; i < ro->r_nents; i++) { | |
415 | struct page *page = sg_page(&ro->r_sg[i]); | |
416 | ||
417 | /* Mark page dirty if it was possibly modified, which | |
418 | * is the case for a RDMA_READ which copies from remote | |
419 | * to local memory */ | |
420 | if (!ro->r_write) | |
421 | set_page_dirty(page); | |
422 | put_page(page); | |
423 | } | |
424 | ||
425 | kfree(ro->r_notifier); | |
426 | kfree(ro); | |
427 | } | |
428 | ||
429 | /* | |
430 | * args is a pointer to an in-kernel copy in the sendmsg cmsg. | |
431 | */ | |
432 | static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs, | |
433 | struct rds_rdma_args *args) | |
434 | { | |
435 | struct rds_iovec vec; | |
436 | struct rds_rdma_op *op = NULL; | |
437 | unsigned int nr_pages; | |
438 | unsigned int max_pages; | |
439 | unsigned int nr_bytes; | |
440 | struct page **pages = NULL; | |
441 | struct rds_iovec __user *local_vec; | |
442 | struct scatterlist *sg; | |
443 | unsigned int nr; | |
444 | unsigned int i, j; | |
445 | int ret; | |
446 | ||
447 | ||
448 | if (rs->rs_bound_addr == 0) { | |
449 | ret = -ENOTCONN; /* XXX not a great errno */ | |
450 | goto out; | |
451 | } | |
452 | ||
453 | if (args->nr_local > (u64)UINT_MAX) { | |
454 | ret = -EMSGSIZE; | |
455 | goto out; | |
456 | } | |
457 | ||
458 | nr_pages = 0; | |
459 | max_pages = 0; | |
460 | ||
461 | local_vec = (struct rds_iovec __user *)(unsigned long) args->local_vec_addr; | |
462 | ||
463 | /* figure out the number of pages in the vector */ | |
464 | for (i = 0; i < args->nr_local; i++) { | |
465 | if (copy_from_user(&vec, &local_vec[i], | |
466 | sizeof(struct rds_iovec))) { | |
467 | ret = -EFAULT; | |
468 | goto out; | |
469 | } | |
470 | ||
471 | nr = rds_pages_in_vec(&vec); | |
472 | if (nr == 0) { | |
473 | ret = -EINVAL; | |
474 | goto out; | |
475 | } | |
476 | ||
477 | max_pages = max(nr, max_pages); | |
478 | nr_pages += nr; | |
479 | } | |
480 | ||
481 | pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL); | |
482 | if (pages == NULL) { | |
483 | ret = -ENOMEM; | |
484 | goto out; | |
485 | } | |
486 | ||
487 | op = kzalloc(offsetof(struct rds_rdma_op, r_sg[nr_pages]), GFP_KERNEL); | |
488 | if (op == NULL) { | |
489 | ret = -ENOMEM; | |
490 | goto out; | |
491 | } | |
492 | ||
493 | op->r_write = !!(args->flags & RDS_RDMA_READWRITE); | |
494 | op->r_fence = !!(args->flags & RDS_RDMA_FENCE); | |
495 | op->r_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME); | |
496 | op->r_recverr = rs->rs_recverr; | |
497 | WARN_ON(!nr_pages); | |
498 | sg_init_table(op->r_sg, nr_pages); | |
499 | ||
500 | if (op->r_notify || op->r_recverr) { | |
501 | /* We allocate an uninitialized notifier here, because | |
502 | * we don't want to do that in the completion handler. We | |
503 | * would have to use GFP_ATOMIC there, and don't want to deal | |
504 | * with failed allocations. | |
505 | */ | |
506 | op->r_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL); | |
507 | if (!op->r_notifier) { | |
508 | ret = -ENOMEM; | |
509 | goto out; | |
510 | } | |
511 | op->r_notifier->n_user_token = args->user_token; | |
512 | op->r_notifier->n_status = RDS_RDMA_SUCCESS; | |
513 | } | |
514 | ||
515 | /* The cookie contains the R_Key of the remote memory region, and | |
516 | * optionally an offset into it. This is how we implement RDMA into | |
517 | * unaligned memory. | |
518 | * When setting up the RDMA, we need to add that offset to the | |
519 | * destination address (which is really an offset into the MR) | |
520 | * FIXME: We may want to move this into ib_rdma.c | |
521 | */ | |
522 | op->r_key = rds_rdma_cookie_key(args->cookie); | |
523 | op->r_remote_addr = args->remote_vec.addr + rds_rdma_cookie_offset(args->cookie); | |
524 | ||
525 | nr_bytes = 0; | |
526 | ||
527 | rdsdebug("RDS: rdma prepare nr_local %llu rva %llx rkey %x\n", | |
528 | (unsigned long long)args->nr_local, | |
529 | (unsigned long long)args->remote_vec.addr, | |
530 | op->r_key); | |
531 | ||
532 | for (i = 0; i < args->nr_local; i++) { | |
533 | if (copy_from_user(&vec, &local_vec[i], | |
534 | sizeof(struct rds_iovec))) { | |
535 | ret = -EFAULT; | |
536 | goto out; | |
537 | } | |
538 | ||
539 | nr = rds_pages_in_vec(&vec); | |
540 | if (nr == 0) { | |
541 | ret = -EINVAL; | |
542 | goto out; | |
543 | } | |
544 | ||
545 | rs->rs_user_addr = vec.addr; | |
546 | rs->rs_user_bytes = vec.bytes; | |
547 | ||
548 | /* did the user change the vec under us? */ | |
549 | if (nr > max_pages || op->r_nents + nr > nr_pages) { | |
550 | ret = -EINVAL; | |
551 | goto out; | |
552 | } | |
553 | /* If it's a WRITE operation, we want to pin the pages for reading. | |
554 | * If it's a READ operation, we need to pin the pages for writing. | |
555 | */ | |
556 | ret = rds_pin_pages(vec.addr & PAGE_MASK, nr, pages, !op->r_write); | |
557 | if (ret < 0) | |
558 | goto out; | |
559 | ||
560 | rdsdebug("RDS: nr_bytes %u nr %u vec.bytes %llu vec.addr %llx\n", | |
561 | nr_bytes, nr, vec.bytes, vec.addr); | |
562 | ||
563 | nr_bytes += vec.bytes; | |
564 | ||
565 | for (j = 0; j < nr; j++) { | |
566 | unsigned int offset = vec.addr & ~PAGE_MASK; | |
567 | ||
568 | sg = &op->r_sg[op->r_nents + j]; | |
569 | sg_set_page(sg, pages[j], | |
570 | min_t(unsigned int, vec.bytes, PAGE_SIZE - offset), | |
571 | offset); | |
572 | ||
573 | rdsdebug("RDS: sg->offset %x sg->len %x vec.addr %llx vec.bytes %llu\n", | |
574 | sg->offset, sg->length, vec.addr, vec.bytes); | |
575 | ||
576 | vec.addr += sg->length; | |
577 | vec.bytes -= sg->length; | |
578 | } | |
579 | ||
580 | op->r_nents += nr; | |
581 | } | |
582 | ||
583 | ||
584 | if (nr_bytes > args->remote_vec.bytes) { | |
585 | rdsdebug("RDS nr_bytes %u remote_bytes %u do not match\n", | |
586 | nr_bytes, | |
587 | (unsigned int) args->remote_vec.bytes); | |
588 | ret = -EINVAL; | |
589 | goto out; | |
590 | } | |
591 | op->r_bytes = nr_bytes; | |
592 | ||
593 | ret = 0; | |
594 | out: | |
595 | kfree(pages); | |
596 | if (ret) { | |
597 | if (op) | |
598 | rds_rdma_free_op(op); | |
599 | op = ERR_PTR(ret); | |
600 | } | |
601 | return op; | |
602 | } | |
603 | ||
604 | /* | |
605 | * The application asks for a RDMA transfer. | |
606 | * Extract all arguments and set up the rdma_op | |
607 | */ | |
608 | int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, | |
609 | struct cmsghdr *cmsg) | |
610 | { | |
611 | struct rds_rdma_op *op; | |
612 | ||
613 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_rdma_args)) | |
614 | || rm->m_rdma_op != NULL) | |
615 | return -EINVAL; | |
616 | ||
617 | op = rds_rdma_prepare(rs, CMSG_DATA(cmsg)); | |
618 | if (IS_ERR(op)) | |
619 | return PTR_ERR(op); | |
620 | rds_stats_inc(s_send_rdma); | |
621 | rm->m_rdma_op = op; | |
622 | return 0; | |
623 | } | |
624 | ||
625 | /* | |
626 | * The application wants us to pass an RDMA destination (aka MR) | |
627 | * to the remote | |
628 | */ | |
629 | int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm, | |
630 | struct cmsghdr *cmsg) | |
631 | { | |
632 | unsigned long flags; | |
633 | struct rds_mr *mr; | |
634 | u32 r_key; | |
635 | int err = 0; | |
636 | ||
637 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(rds_rdma_cookie_t)) | |
638 | || rm->m_rdma_cookie != 0) | |
639 | return -EINVAL; | |
640 | ||
641 | memcpy(&rm->m_rdma_cookie, CMSG_DATA(cmsg), sizeof(rm->m_rdma_cookie)); | |
642 | ||
643 | /* We are reusing a previously mapped MR here. Most likely, the | |
644 | * application has written to the buffer, so we need to explicitly | |
645 | * flush those writes to RAM. Otherwise the HCA may not see them | |
646 | * when doing a DMA from that buffer. | |
647 | */ | |
648 | r_key = rds_rdma_cookie_key(rm->m_rdma_cookie); | |
649 | ||
650 | spin_lock_irqsave(&rs->rs_rdma_lock, flags); | |
651 | mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL); | |
652 | if (mr == NULL) | |
653 | err = -EINVAL; /* invalid r_key */ | |
654 | else | |
655 | atomic_inc(&mr->r_refcount); | |
656 | spin_unlock_irqrestore(&rs->rs_rdma_lock, flags); | |
657 | ||
658 | if (mr) { | |
659 | mr->r_trans->sync_mr(mr->r_trans_private, DMA_TO_DEVICE); | |
660 | rm->m_rdma_mr = mr; | |
661 | } | |
662 | return err; | |
663 | } | |
664 | ||
665 | /* | |
666 | * The application passes us an address range it wants to enable RDMA | |
667 | * to/from. We map the area, and save the <R_Key,offset> pair | |
668 | * in rm->m_rdma_cookie. This causes it to be sent along to the peer | |
669 | * in an extension header. | |
670 | */ | |
671 | int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm, | |
672 | struct cmsghdr *cmsg) | |
673 | { | |
674 | if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct rds_get_mr_args)) | |
675 | || rm->m_rdma_cookie != 0) | |
676 | return -EINVAL; | |
677 | ||
678 | return __rds_rdma_map(rs, CMSG_DATA(cmsg), &rm->m_rdma_cookie, &rm->m_rdma_mr); | |
679 | } |