1 /*
2 * Copyright (c) 2006, 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/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/export.h>
36 #include <linux/skbuff.h>
37 #include <linux/list.h>
38 #include <linux/errqueue.h>
39
40 #include "rds.h"
41
42 static unsigned int rds_exthdr_size[__RDS_EXTHDR_MAX] = {
43 [RDS_EXTHDR_NONE] = 0,
44 [RDS_EXTHDR_VERSION] = sizeof(struct rds_ext_header_version),
45 [RDS_EXTHDR_RDMA] = sizeof(struct rds_ext_header_rdma),
46 [RDS_EXTHDR_RDMA_DEST] = sizeof(struct rds_ext_header_rdma_dest),
47 [RDS_EXTHDR_NPATHS] = sizeof(u16),
48 [RDS_EXTHDR_GEN_NUM] = sizeof(u32),
49 };
50
51 void rds_message_addref(struct rds_message *rm)
52 {
53 rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
54 refcount_inc(&rm->m_refcount);
55 }
56 EXPORT_SYMBOL_GPL(rds_message_addref);
57
58 static inline bool rds_zcookie_add(struct rds_msg_zcopy_info *info, u32 cookie)
59 {
60 struct rds_zcopy_cookies *ck = &info->zcookies;
61 int ncookies = ck->num;
62
63 if (ncookies == RDS_MAX_ZCOOKIES)
64 return false;
65 ck->cookies[ncookies] = cookie;
66 ck->num = ++ncookies;
67 return true;
68 }
69
70 static struct rds_msg_zcopy_info *rds_info_from_znotifier(struct rds_znotifier *znotif)
71 {
72 return container_of(znotif, struct rds_msg_zcopy_info, znotif);
73 }
74
75 void rds_notify_msg_zcopy_purge(struct rds_msg_zcopy_queue *q)
76 {
77 unsigned long flags;
78 LIST_HEAD(copy);
79 struct rds_msg_zcopy_info *info, *tmp;
80
81 spin_lock_irqsave(&q->lock, flags);
82 list_splice(&q->zcookie_head, ©);
83 INIT_LIST_HEAD(&q->zcookie_head);
84 spin_unlock_irqrestore(&q->lock, flags);
85
86 list_for_each_entry_safe(info, tmp, ©, rs_zcookie_next) {
87 list_del(&info->rs_zcookie_next);
88 kfree(info);
89 }
90 }
91
92 static void rds_rm_zerocopy_callback(struct rds_sock *rs,
93 struct rds_znotifier *znotif)
94 {
95 struct rds_msg_zcopy_info *info;
96 struct rds_msg_zcopy_queue *q;
97 u32 cookie = znotif->z_cookie;
98 struct rds_zcopy_cookies *ck;
99 struct list_head *head;
100 unsigned long flags;
101
102 mm_unaccount_pinned_pages(&znotif->z_mmp);
103 q = &rs->rs_zcookie_queue;
104 spin_lock_irqsave(&q->lock, flags);
105 head = &q->zcookie_head;
106 if (!list_empty(head)) {
107 info = list_first_entry(head, struct rds_msg_zcopy_info,
108 rs_zcookie_next);
109 if (rds_zcookie_add(info, cookie)) {
110 spin_unlock_irqrestore(&q->lock, flags);
111 kfree(rds_info_from_znotifier(znotif));
112 /* caller invokes rds_wake_sk_sleep() */
113 return;
114 }
115 }
116
117 info = rds_info_from_znotifier(znotif);
118 ck = &info->zcookies;
119 memset(ck, 0, sizeof(*ck));
120 WARN_ON(!rds_zcookie_add(info, cookie));
121 list_add_tail(&info->rs_zcookie_next, &q->zcookie_head);
122
123 spin_unlock_irqrestore(&q->lock, flags);
124 /* caller invokes rds_wake_sk_sleep() */
125 }
126
127 /*
128 * This relies on dma_map_sg() not touching sg[].page during merging.
129 */
130 static void rds_message_purge(struct rds_message *rm)
131 {
132 unsigned long i, flags;
133 bool zcopy = false;
134
135 if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
136 return;
137
138 spin_lock_irqsave(&rm->m_rs_lock, flags);
139 if (rm->m_rs) {
140 struct rds_sock *rs = rm->m_rs;
141
142 if (rm->data.op_mmp_znotifier) {
143 zcopy = true;
144 rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier);
145 rds_wake_sk_sleep(rs);
146 rm->data.op_mmp_znotifier = NULL;
147 }
148 sock_put(rds_rs_to_sk(rs));
149 rm->m_rs = NULL;
150 }
151 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
152
153 for (i = 0; i < rm->data.op_nents; i++) {
154 /* XXX will have to put_page for page refs */
155 if (!zcopy)
156 __free_page(sg_page(&rm->data.op_sg[i]));
157 else
158 put_page(sg_page(&rm->data.op_sg[i]));
159 }
160 rm->data.op_nents = 0;
161
162 if (rm->rdma.op_active)
163 rds_rdma_free_op(&rm->rdma);
164 if (rm->rdma.op_rdma_mr)
165 kref_put(&rm->rdma.op_rdma_mr->r_kref, __rds_put_mr_final);
166
167 if (rm->atomic.op_active)
168 rds_atomic_free_op(&rm->atomic);
169 if (rm->atomic.op_rdma_mr)
170 kref_put(&rm->atomic.op_rdma_mr->r_kref, __rds_put_mr_final);
171 }
172
173 void rds_message_put(struct rds_message *rm)
174 {
175 rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
176 WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
177 if (refcount_dec_and_test(&rm->m_refcount)) {
178 BUG_ON(!list_empty(&rm->m_sock_item));
179 BUG_ON(!list_empty(&rm->m_conn_item));
180 rds_message_purge(rm);
181
182 kfree(rm);
183 }
184 }
185 EXPORT_SYMBOL_GPL(rds_message_put);
186
187 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
188 __be16 dport, u64 seq)
189 {
190 hdr->h_flags = 0;
191 hdr->h_sport = sport;
192 hdr->h_dport = dport;
193 hdr->h_sequence = cpu_to_be64(seq);
194 hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
195 }
196 EXPORT_SYMBOL_GPL(rds_message_populate_header);
197
198 int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
199 const void *data, unsigned int len)
200 {
201 unsigned int ext_len = sizeof(u8) + len;
202 unsigned char *dst;
203
204 /* For now, refuse to add more than one extension header */
205 if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
206 return 0;
207
208 if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
209 return 0;
210
211 if (ext_len >= RDS_HEADER_EXT_SPACE)
212 return 0;
213 dst = hdr->h_exthdr;
214
215 *dst++ = type;
216 memcpy(dst, data, len);
217
218 dst[len] = RDS_EXTHDR_NONE;
219 return 1;
220 }
221 EXPORT_SYMBOL_GPL(rds_message_add_extension);
222
223 /*
224 * If a message has extension headers, retrieve them here.
225 * Call like this:
226 *
227 * unsigned int pos = 0;
228 *
229 * while (1) {
230 * buflen = sizeof(buffer);
231 * type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
232 * if (type == RDS_EXTHDR_NONE)
233 * break;
234 * ...
235 * }
236 */
237 int rds_message_next_extension(struct rds_header *hdr,
238 unsigned int *pos, void *buf, unsigned int *buflen)
239 {
240 unsigned int offset, ext_type, ext_len;
241 u8 *src = hdr->h_exthdr;
242
243 offset = *pos;
244 if (offset >= RDS_HEADER_EXT_SPACE)
245 goto none;
246
247 /* Get the extension type and length. For now, the
248 * length is implied by the extension type. */
249 ext_type = src[offset++];
250
251 if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
252 goto none;
253 ext_len = rds_exthdr_size[ext_type];
254 if (offset + ext_len > RDS_HEADER_EXT_SPACE)
255 goto none;
256
257 *pos = offset + ext_len;
258 if (ext_len < *buflen)
259 *buflen = ext_len;
260 memcpy(buf, src + offset, *buflen);
261 return ext_type;
262
263 none:
264 *pos = RDS_HEADER_EXT_SPACE;
265 *buflen = 0;
266 return RDS_EXTHDR_NONE;
267 }
268
269 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
270 {
271 struct rds_ext_header_rdma_dest ext_hdr;
272
273 ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
274 ext_hdr.h_rdma_offset = cpu_to_be32(offset);
275 return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
276 }
277 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
278
279 /*
280 * Each rds_message is allocated with extra space for the scatterlist entries
281 * rds ops will need. This is to minimize memory allocation count. Then, each rds op
282 * can grab SGs when initializing its part of the rds_message.
283 */
284 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
285 {
286 struct rds_message *rm;
287
288 if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
289 return NULL;
290
291 rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
292 if (!rm)
293 goto out;
294
295 rm->m_used_sgs = 0;
296 rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
297
298 refcount_set(&rm->m_refcount, 1);
299 INIT_LIST_HEAD(&rm->m_sock_item);
300 INIT_LIST_HEAD(&rm->m_conn_item);
301 spin_lock_init(&rm->m_rs_lock);
302 init_waitqueue_head(&rm->m_flush_wait);
303
304 out:
305 return rm;
306 }
307
308 /*
309 * RDS ops use this to grab SG entries from the rm's sg pool.
310 */
311 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
312 {
313 struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
314 struct scatterlist *sg_ret;
315
316 if (nents <= 0) {
317 pr_warn("rds: alloc sgs failed! nents <= 0\n");
318 return ERR_PTR(-EINVAL);
319 }
320
321 if (rm->m_used_sgs + nents > rm->m_total_sgs) {
322 pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
323 rm->m_total_sgs, rm->m_used_sgs, nents);
324 return ERR_PTR(-ENOMEM);
325 }
326
327 sg_ret = &sg_first[rm->m_used_sgs];
328 sg_init_table(sg_ret, nents);
329 rm->m_used_sgs += nents;
330
331 return sg_ret;
332 }
333
334 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
335 {
336 struct rds_message *rm;
337 unsigned int i;
338 int num_sgs = DIV_ROUND_UP(total_len, PAGE_SIZE);
339 int extra_bytes = num_sgs * sizeof(struct scatterlist);
340
341 rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
342 if (!rm)
343 return ERR_PTR(-ENOMEM);
344
345 set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
346 rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
347 rm->data.op_nents = DIV_ROUND_UP(total_len, PAGE_SIZE);
348 rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
349 if (IS_ERR(rm->data.op_sg)) {
350 void *err = ERR_CAST(rm->data.op_sg);
351 rds_message_put(rm);
352 return err;
353 }
354
355 for (i = 0; i < rm->data.op_nents; ++i) {
356 sg_set_page(&rm->data.op_sg[i],
357 virt_to_page((void *)page_addrs[i]),
358 PAGE_SIZE, 0);
359 }
360
361 return rm;
362 }
363
364 static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter *from)
365 {
366 struct scatterlist *sg;
367 int ret = 0;
368 int length = iov_iter_count(from);
369 struct rds_msg_zcopy_info *info;
370
371 rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
372
373 /*
374 * now allocate and copy in the data payload.
375 */
376 sg = rm->data.op_sg;
377
378 info = kzalloc(sizeof(*info), GFP_KERNEL);
379 if (!info)
380 return -ENOMEM;
381 INIT_LIST_HEAD(&info->rs_zcookie_next);
382 rm->data.op_mmp_znotifier = &info->znotif;
383 if (mm_account_pinned_pages(&rm->data.op_mmp_znotifier->z_mmp,
384 length)) {
385 ret = -ENOMEM;
386 goto err;
387 }
388 while (iov_iter_count(from)) {
389 struct page *pages;
390 size_t start;
391 ssize_t copied;
392
393 copied = iov_iter_get_pages2(from, &pages, PAGE_SIZE,
394 1, &start);
395 if (copied < 0) {
396 struct mmpin *mmp;
397 int i;
398
399 for (i = 0; i < rm->data.op_nents; i++)
400 put_page(sg_page(&rm->data.op_sg[i]));
401 mmp = &rm->data.op_mmp_znotifier->z_mmp;
402 mm_unaccount_pinned_pages(mmp);
403 ret = -EFAULT;
404 goto err;
405 }
406 length -= copied;
407 sg_set_page(sg, pages, copied, start);
408 rm->data.op_nents++;
409 sg++;
410 }
411 WARN_ON_ONCE(length != 0);
412 return ret;
413 err:
414 kfree(info);
415 rm->data.op_mmp_znotifier = NULL;
416 return ret;
417 }
418
419 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from,
420 bool zcopy)
421 {
422 unsigned long to_copy, nbytes;
423 unsigned long sg_off;
424 struct scatterlist *sg;
425 int ret = 0;
426
427 rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
428
429 /* now allocate and copy in the data payload. */
430 sg = rm->data.op_sg;
431 sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
432
433 if (zcopy)
434 return rds_message_zcopy_from_user(rm, from);
435
436 while (iov_iter_count(from)) {
437 if (!sg_page(sg)) {
438 ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
439 GFP_HIGHUSER);
440 if (ret)
441 return ret;
442 rm->data.op_nents++;
443 sg_off = 0;
444 }
445
446 to_copy = min_t(unsigned long, iov_iter_count(from),
447 sg->length - sg_off);
448
449 rds_stats_add(s_copy_from_user, to_copy);
450 nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
451 to_copy, from);
452 if (nbytes != to_copy)
453 return -EFAULT;
454
455 sg_off += to_copy;
456
457 if (sg_off == sg->length)
458 sg++;
459 }
460
461 return ret;
462 }
463
464 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
465 {
466 struct rds_message *rm;
467 struct scatterlist *sg;
468 unsigned long to_copy;
469 unsigned long vec_off;
470 int copied;
471 int ret;
472 u32 len;
473
474 rm = container_of(inc, struct rds_message, m_inc);
475 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
476
477 sg = rm->data.op_sg;
478 vec_off = 0;
479 copied = 0;
480
481 while (iov_iter_count(to) && copied < len) {
482 to_copy = min_t(unsigned long, iov_iter_count(to),
483 sg->length - vec_off);
484 to_copy = min_t(unsigned long, to_copy, len - copied);
485
486 rds_stats_add(s_copy_to_user, to_copy);
487 ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
488 to_copy, to);
489 if (ret != to_copy)
490 return -EFAULT;
491
492 vec_off += to_copy;
493 copied += to_copy;
494
495 if (vec_off == sg->length) {
496 vec_off = 0;
497 sg++;
498 }
499 }
500
501 return copied;
502 }
503
504 /*
505 * If the message is still on the send queue, wait until the transport
506 * is done with it. This is particularly important for RDMA operations.
507 */
508 void rds_message_wait(struct rds_message *rm)
509 {
510 wait_event_interruptible(rm->m_flush_wait,
511 !test_bit(RDS_MSG_MAPPED, &rm->m_flags));
512 }
513
514 void rds_message_unmapped(struct rds_message *rm)
515 {
516 clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
517 wake_up_interruptible(&rm->m_flush_wait);
518 }
519 EXPORT_SYMBOL_GPL(rds_message_unmapped);
520
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