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[mirror_ubuntu-bionic-kernel.git] / net / rds / message.c
1 /*
2 * Copyright (c) 2006 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/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/export.h>
36
37 #include "rds.h"
38
39 static unsigned int rds_exthdr_size[__RDS_EXTHDR_MAX] = {
40 [RDS_EXTHDR_NONE] = 0,
41 [RDS_EXTHDR_VERSION] = sizeof(struct rds_ext_header_version),
42 [RDS_EXTHDR_RDMA] = sizeof(struct rds_ext_header_rdma),
43 [RDS_EXTHDR_RDMA_DEST] = sizeof(struct rds_ext_header_rdma_dest),
44 [RDS_EXTHDR_NPATHS] = sizeof(u16),
45 };
46
47
48 void rds_message_addref(struct rds_message *rm)
49 {
50 rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
51 atomic_inc(&rm->m_refcount);
52 }
53 EXPORT_SYMBOL_GPL(rds_message_addref);
54
55 /*
56 * This relies on dma_map_sg() not touching sg[].page during merging.
57 */
58 static void rds_message_purge(struct rds_message *rm)
59 {
60 unsigned long i;
61
62 if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
63 return;
64
65 for (i = 0; i < rm->data.op_nents; i++) {
66 rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i]));
67 /* XXX will have to put_page for page refs */
68 __free_page(sg_page(&rm->data.op_sg[i]));
69 }
70 rm->data.op_nents = 0;
71
72 if (rm->rdma.op_active)
73 rds_rdma_free_op(&rm->rdma);
74 if (rm->rdma.op_rdma_mr)
75 rds_mr_put(rm->rdma.op_rdma_mr);
76
77 if (rm->atomic.op_active)
78 rds_atomic_free_op(&rm->atomic);
79 if (rm->atomic.op_rdma_mr)
80 rds_mr_put(rm->atomic.op_rdma_mr);
81 }
82
83 void rds_message_put(struct rds_message *rm)
84 {
85 rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
86 WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
87 if (atomic_dec_and_test(&rm->m_refcount)) {
88 BUG_ON(!list_empty(&rm->m_sock_item));
89 BUG_ON(!list_empty(&rm->m_conn_item));
90 rds_message_purge(rm);
91
92 kfree(rm);
93 }
94 }
95 EXPORT_SYMBOL_GPL(rds_message_put);
96
97 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
98 __be16 dport, u64 seq)
99 {
100 hdr->h_flags = 0;
101 hdr->h_sport = sport;
102 hdr->h_dport = dport;
103 hdr->h_sequence = cpu_to_be64(seq);
104 hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
105 }
106 EXPORT_SYMBOL_GPL(rds_message_populate_header);
107
108 int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
109 const void *data, unsigned int len)
110 {
111 unsigned int ext_len = sizeof(u8) + len;
112 unsigned char *dst;
113
114 /* For now, refuse to add more than one extension header */
115 if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
116 return 0;
117
118 if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
119 return 0;
120
121 if (ext_len >= RDS_HEADER_EXT_SPACE)
122 return 0;
123 dst = hdr->h_exthdr;
124
125 *dst++ = type;
126 memcpy(dst, data, len);
127
128 dst[len] = RDS_EXTHDR_NONE;
129 return 1;
130 }
131 EXPORT_SYMBOL_GPL(rds_message_add_extension);
132
133 /*
134 * If a message has extension headers, retrieve them here.
135 * Call like this:
136 *
137 * unsigned int pos = 0;
138 *
139 * while (1) {
140 * buflen = sizeof(buffer);
141 * type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
142 * if (type == RDS_EXTHDR_NONE)
143 * break;
144 * ...
145 * }
146 */
147 int rds_message_next_extension(struct rds_header *hdr,
148 unsigned int *pos, void *buf, unsigned int *buflen)
149 {
150 unsigned int offset, ext_type, ext_len;
151 u8 *src = hdr->h_exthdr;
152
153 offset = *pos;
154 if (offset >= RDS_HEADER_EXT_SPACE)
155 goto none;
156
157 /* Get the extension type and length. For now, the
158 * length is implied by the extension type. */
159 ext_type = src[offset++];
160
161 if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
162 goto none;
163 ext_len = rds_exthdr_size[ext_type];
164 if (offset + ext_len > RDS_HEADER_EXT_SPACE)
165 goto none;
166
167 *pos = offset + ext_len;
168 if (ext_len < *buflen)
169 *buflen = ext_len;
170 memcpy(buf, src + offset, *buflen);
171 return ext_type;
172
173 none:
174 *pos = RDS_HEADER_EXT_SPACE;
175 *buflen = 0;
176 return RDS_EXTHDR_NONE;
177 }
178
179 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
180 {
181 struct rds_ext_header_rdma_dest ext_hdr;
182
183 ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
184 ext_hdr.h_rdma_offset = cpu_to_be32(offset);
185 return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
186 }
187 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
188
189 /*
190 * Each rds_message is allocated with extra space for the scatterlist entries
191 * rds ops will need. This is to minimize memory allocation count. Then, each rds op
192 * can grab SGs when initializing its part of the rds_message.
193 */
194 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
195 {
196 struct rds_message *rm;
197
198 if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
199 return NULL;
200
201 rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
202 if (!rm)
203 goto out;
204
205 rm->m_used_sgs = 0;
206 rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
207
208 atomic_set(&rm->m_refcount, 1);
209 INIT_LIST_HEAD(&rm->m_sock_item);
210 INIT_LIST_HEAD(&rm->m_conn_item);
211 spin_lock_init(&rm->m_rs_lock);
212 init_waitqueue_head(&rm->m_flush_wait);
213
214 out:
215 return rm;
216 }
217
218 /*
219 * RDS ops use this to grab SG entries from the rm's sg pool.
220 */
221 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
222 {
223 struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
224 struct scatterlist *sg_ret;
225
226 WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
227 WARN_ON(!nents);
228
229 if (rm->m_used_sgs + nents > rm->m_total_sgs)
230 return NULL;
231
232 sg_ret = &sg_first[rm->m_used_sgs];
233 sg_init_table(sg_ret, nents);
234 rm->m_used_sgs += nents;
235
236 return sg_ret;
237 }
238
239 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
240 {
241 struct rds_message *rm;
242 unsigned int i;
243 int num_sgs = ceil(total_len, PAGE_SIZE);
244 int extra_bytes = num_sgs * sizeof(struct scatterlist);
245
246 rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
247 if (!rm)
248 return ERR_PTR(-ENOMEM);
249
250 set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
251 rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
252 rm->data.op_nents = ceil(total_len, PAGE_SIZE);
253 rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
254 if (!rm->data.op_sg) {
255 rds_message_put(rm);
256 return ERR_PTR(-ENOMEM);
257 }
258
259 for (i = 0; i < rm->data.op_nents; ++i) {
260 sg_set_page(&rm->data.op_sg[i],
261 virt_to_page(page_addrs[i]),
262 PAGE_SIZE, 0);
263 }
264
265 return rm;
266 }
267
268 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
269 {
270 unsigned long to_copy, nbytes;
271 unsigned long sg_off;
272 struct scatterlist *sg;
273 int ret = 0;
274
275 rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
276
277 /*
278 * now allocate and copy in the data payload.
279 */
280 sg = rm->data.op_sg;
281 sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
282
283 while (iov_iter_count(from)) {
284 if (!sg_page(sg)) {
285 ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
286 GFP_HIGHUSER);
287 if (ret)
288 return ret;
289 rm->data.op_nents++;
290 sg_off = 0;
291 }
292
293 to_copy = min_t(unsigned long, iov_iter_count(from),
294 sg->length - sg_off);
295
296 rds_stats_add(s_copy_from_user, to_copy);
297 nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
298 to_copy, from);
299 if (nbytes != to_copy)
300 return -EFAULT;
301
302 sg_off += to_copy;
303
304 if (sg_off == sg->length)
305 sg++;
306 }
307
308 return ret;
309 }
310
311 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
312 {
313 struct rds_message *rm;
314 struct scatterlist *sg;
315 unsigned long to_copy;
316 unsigned long vec_off;
317 int copied;
318 int ret;
319 u32 len;
320
321 rm = container_of(inc, struct rds_message, m_inc);
322 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
323
324 sg = rm->data.op_sg;
325 vec_off = 0;
326 copied = 0;
327
328 while (iov_iter_count(to) && copied < len) {
329 to_copy = min_t(unsigned long, iov_iter_count(to),
330 sg->length - vec_off);
331 to_copy = min_t(unsigned long, to_copy, len - copied);
332
333 rds_stats_add(s_copy_to_user, to_copy);
334 ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
335 to_copy, to);
336 if (ret != to_copy)
337 return -EFAULT;
338
339 vec_off += to_copy;
340 copied += to_copy;
341
342 if (vec_off == sg->length) {
343 vec_off = 0;
344 sg++;
345 }
346 }
347
348 return copied;
349 }
350
351 /*
352 * If the message is still on the send queue, wait until the transport
353 * is done with it. This is particularly important for RDMA operations.
354 */
355 void rds_message_wait(struct rds_message *rm)
356 {
357 wait_event_interruptible(rm->m_flush_wait,
358 !test_bit(RDS_MSG_MAPPED, &rm->m_flags));
359 }
360
361 void rds_message_unmapped(struct rds_message *rm)
362 {
363 clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
364 wake_up_interruptible(&rm->m_flush_wait);
365 }
366 EXPORT_SYMBOL_GPL(rds_message_unmapped);
367