xref: /openbmc/linux/net/rds/message.c (revision e8e0929d)
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 
35 #include "rds.h"
36 #include "rdma.h"
37 
38 static DECLARE_WAIT_QUEUE_HEAD(rds_message_flush_waitq);
39 
40 static unsigned int	rds_exthdr_size[__RDS_EXTHDR_MAX] = {
41 [RDS_EXTHDR_NONE]	= 0,
42 [RDS_EXTHDR_VERSION]	= sizeof(struct rds_ext_header_version),
43 [RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
44 [RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
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->m_nents; i++) {
66 		rdsdebug("putting data page %p\n", (void *)sg_page(&rm->m_sg[i]));
67 		/* XXX will have to put_page for page refs */
68 		__free_page(sg_page(&rm->m_sg[i]));
69 	}
70 	rm->m_nents = 0;
71 
72 	if (rm->m_rdma_op)
73 		rds_rdma_free_op(rm->m_rdma_op);
74 	if (rm->m_rdma_mr)
75 		rds_mr_put(rm->m_rdma_mr);
76 }
77 
78 void rds_message_inc_purge(struct rds_incoming *inc)
79 {
80 	struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
81 	rds_message_purge(rm);
82 }
83 
84 void rds_message_put(struct rds_message *rm)
85 {
86 	rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
87 
88 	if (atomic_dec_and_test(&rm->m_refcount)) {
89 		BUG_ON(!list_empty(&rm->m_sock_item));
90 		BUG_ON(!list_empty(&rm->m_conn_item));
91 		rds_message_purge(rm);
92 
93 		kfree(rm);
94 	}
95 }
96 EXPORT_SYMBOL_GPL(rds_message_put);
97 
98 void rds_message_inc_free(struct rds_incoming *inc)
99 {
100 	struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
101 	rds_message_put(rm);
102 }
103 
104 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
105 				 __be16 dport, u64 seq)
106 {
107 	hdr->h_flags = 0;
108 	hdr->h_sport = sport;
109 	hdr->h_dport = dport;
110 	hdr->h_sequence = cpu_to_be64(seq);
111 	hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
112 }
113 EXPORT_SYMBOL_GPL(rds_message_populate_header);
114 
115 int rds_message_add_extension(struct rds_header *hdr,
116 		unsigned int type, const void *data, unsigned int len)
117 {
118 	unsigned int ext_len = sizeof(u8) + len;
119 	unsigned char *dst;
120 
121 	/* For now, refuse to add more than one extension header */
122 	if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
123 		return 0;
124 
125 	if (type >= __RDS_EXTHDR_MAX
126 	 || len != rds_exthdr_size[type])
127 		return 0;
128 
129 	if (ext_len >= RDS_HEADER_EXT_SPACE)
130 		return 0;
131 	dst = hdr->h_exthdr;
132 
133 	*dst++ = type;
134 	memcpy(dst, data, len);
135 
136 	dst[len] = RDS_EXTHDR_NONE;
137 	return 1;
138 }
139 EXPORT_SYMBOL_GPL(rds_message_add_extension);
140 
141 /*
142  * If a message has extension headers, retrieve them here.
143  * Call like this:
144  *
145  * unsigned int pos = 0;
146  *
147  * while (1) {
148  *	buflen = sizeof(buffer);
149  *	type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
150  *	if (type == RDS_EXTHDR_NONE)
151  *		break;
152  *	...
153  * }
154  */
155 int rds_message_next_extension(struct rds_header *hdr,
156 		unsigned int *pos, void *buf, unsigned int *buflen)
157 {
158 	unsigned int offset, ext_type, ext_len;
159 	u8 *src = hdr->h_exthdr;
160 
161 	offset = *pos;
162 	if (offset >= RDS_HEADER_EXT_SPACE)
163 		goto none;
164 
165 	/* Get the extension type and length. For now, the
166 	 * length is implied by the extension type. */
167 	ext_type = src[offset++];
168 
169 	if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
170 		goto none;
171 	ext_len = rds_exthdr_size[ext_type];
172 	if (offset + ext_len > RDS_HEADER_EXT_SPACE)
173 		goto none;
174 
175 	*pos = offset + ext_len;
176 	if (ext_len < *buflen)
177 		*buflen = ext_len;
178 	memcpy(buf, src + offset, *buflen);
179 	return ext_type;
180 
181 none:
182 	*pos = RDS_HEADER_EXT_SPACE;
183 	*buflen = 0;
184 	return RDS_EXTHDR_NONE;
185 }
186 
187 int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version)
188 {
189 	struct rds_ext_header_version ext_hdr;
190 
191 	ext_hdr.h_version = cpu_to_be32(version);
192 	return rds_message_add_extension(hdr, RDS_EXTHDR_VERSION, &ext_hdr, sizeof(ext_hdr));
193 }
194 
195 int rds_message_get_version_extension(struct rds_header *hdr, unsigned int *version)
196 {
197 	struct rds_ext_header_version ext_hdr;
198 	unsigned int pos = 0, len = sizeof(ext_hdr);
199 
200 	/* We assume the version extension is the only one present */
201 	if (rds_message_next_extension(hdr, &pos, &ext_hdr, &len) != RDS_EXTHDR_VERSION)
202 		return 0;
203 	*version = be32_to_cpu(ext_hdr.h_version);
204 	return 1;
205 }
206 
207 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
208 {
209 	struct rds_ext_header_rdma_dest ext_hdr;
210 
211 	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
212 	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
213 	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
214 }
215 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
216 
217 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp)
218 {
219 	struct rds_message *rm;
220 
221 	rm = kzalloc(sizeof(struct rds_message) +
222 		     (nents * sizeof(struct scatterlist)), gfp);
223 	if (!rm)
224 		goto out;
225 
226 	if (nents)
227 		sg_init_table(rm->m_sg, nents);
228 	atomic_set(&rm->m_refcount, 1);
229 	INIT_LIST_HEAD(&rm->m_sock_item);
230 	INIT_LIST_HEAD(&rm->m_conn_item);
231 	spin_lock_init(&rm->m_rs_lock);
232 
233 out:
234 	return rm;
235 }
236 
237 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
238 {
239 	struct rds_message *rm;
240 	unsigned int i;
241 
242 	rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
243 	if (rm == NULL)
244 		return ERR_PTR(-ENOMEM);
245 
246 	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
247 	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
248 	rm->m_nents = ceil(total_len, PAGE_SIZE);
249 
250 	for (i = 0; i < rm->m_nents; ++i) {
251 		sg_set_page(&rm->m_sg[i],
252 				virt_to_page(page_addrs[i]),
253 				PAGE_SIZE, 0);
254 	}
255 
256 	return rm;
257 }
258 
259 struct rds_message *rds_message_copy_from_user(struct iovec *first_iov,
260 					       size_t total_len)
261 {
262 	unsigned long to_copy;
263 	unsigned long iov_off;
264 	unsigned long sg_off;
265 	struct rds_message *rm;
266 	struct iovec *iov;
267 	struct scatterlist *sg;
268 	int ret;
269 
270 	rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
271 	if (rm == NULL) {
272 		ret = -ENOMEM;
273 		goto out;
274 	}
275 
276 	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
277 
278 	/*
279 	 * now allocate and copy in the data payload.
280 	 */
281 	sg = rm->m_sg;
282 	iov = first_iov;
283 	iov_off = 0;
284 	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
285 
286 	while (total_len) {
287 		if (sg_page(sg) == NULL) {
288 			ret = rds_page_remainder_alloc(sg, total_len,
289 						       GFP_HIGHUSER);
290 			if (ret)
291 				goto out;
292 			rm->m_nents++;
293 			sg_off = 0;
294 		}
295 
296 		while (iov_off == iov->iov_len) {
297 			iov_off = 0;
298 			iov++;
299 		}
300 
301 		to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
302 		to_copy = min_t(size_t, to_copy, total_len);
303 
304 		rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
305 			 "sg [%p, %u, %u] + %lu\n",
306 			 to_copy, iov->iov_base, iov->iov_len, iov_off,
307 			 (void *)sg_page(sg), sg->offset, sg->length, sg_off);
308 
309 		ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
310 					      iov->iov_base + iov_off,
311 					      to_copy);
312 		if (ret)
313 			goto out;
314 
315 		iov_off += to_copy;
316 		total_len -= to_copy;
317 		sg_off += to_copy;
318 
319 		if (sg_off == sg->length)
320 			sg++;
321 	}
322 
323 	ret = 0;
324 out:
325 	if (ret) {
326 		if (rm)
327 			rds_message_put(rm);
328 		rm = ERR_PTR(ret);
329 	}
330 	return rm;
331 }
332 
333 int rds_message_inc_copy_to_user(struct rds_incoming *inc,
334 				 struct iovec *first_iov, size_t size)
335 {
336 	struct rds_message *rm;
337 	struct iovec *iov;
338 	struct scatterlist *sg;
339 	unsigned long to_copy;
340 	unsigned long iov_off;
341 	unsigned long vec_off;
342 	int copied;
343 	int ret;
344 	u32 len;
345 
346 	rm = container_of(inc, struct rds_message, m_inc);
347 	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
348 
349 	iov = first_iov;
350 	iov_off = 0;
351 	sg = rm->m_sg;
352 	vec_off = 0;
353 	copied = 0;
354 
355 	while (copied < size && copied < len) {
356 		while (iov_off == iov->iov_len) {
357 			iov_off = 0;
358 			iov++;
359 		}
360 
361 		to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
362 		to_copy = min_t(size_t, to_copy, size - copied);
363 		to_copy = min_t(unsigned long, to_copy, len - copied);
364 
365 		rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
366 			 "sg [%p, %u, %u] + %lu\n",
367 			 to_copy, iov->iov_base, iov->iov_len, iov_off,
368 			 sg_page(sg), sg->offset, sg->length, vec_off);
369 
370 		ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
371 					    iov->iov_base + iov_off,
372 					    to_copy);
373 		if (ret) {
374 			copied = ret;
375 			break;
376 		}
377 
378 		iov_off += to_copy;
379 		vec_off += to_copy;
380 		copied += to_copy;
381 
382 		if (vec_off == sg->length) {
383 			vec_off = 0;
384 			sg++;
385 		}
386 	}
387 
388 	return copied;
389 }
390 
391 /*
392  * If the message is still on the send queue, wait until the transport
393  * is done with it. This is particularly important for RDMA operations.
394  */
395 void rds_message_wait(struct rds_message *rm)
396 {
397 	wait_event(rds_message_flush_waitq,
398 			!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
399 }
400 
401 void rds_message_unmapped(struct rds_message *rm)
402 {
403 	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
404 	if (waitqueue_active(&rds_message_flush_waitq))
405 		wake_up(&rds_message_flush_waitq);
406 }
407 EXPORT_SYMBOL_GPL(rds_message_unmapped);
408 
409