xref: /openbmc/linux/net/rds/message.c (revision a09d2831)
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 || len != rds_exthdr_size[type])
126 		return 0;
127 
128 	if (ext_len >= RDS_HEADER_EXT_SPACE)
129 		return 0;
130 	dst = hdr->h_exthdr;
131 
132 	*dst++ = type;
133 	memcpy(dst, data, len);
134 
135 	dst[len] = RDS_EXTHDR_NONE;
136 	return 1;
137 }
138 EXPORT_SYMBOL_GPL(rds_message_add_extension);
139 
140 /*
141  * If a message has extension headers, retrieve them here.
142  * Call like this:
143  *
144  * unsigned int pos = 0;
145  *
146  * while (1) {
147  *	buflen = sizeof(buffer);
148  *	type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
149  *	if (type == RDS_EXTHDR_NONE)
150  *		break;
151  *	...
152  * }
153  */
154 int rds_message_next_extension(struct rds_header *hdr,
155 		unsigned int *pos, void *buf, unsigned int *buflen)
156 {
157 	unsigned int offset, ext_type, ext_len;
158 	u8 *src = hdr->h_exthdr;
159 
160 	offset = *pos;
161 	if (offset >= RDS_HEADER_EXT_SPACE)
162 		goto none;
163 
164 	/* Get the extension type and length. For now, the
165 	 * length is implied by the extension type. */
166 	ext_type = src[offset++];
167 
168 	if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
169 		goto none;
170 	ext_len = rds_exthdr_size[ext_type];
171 	if (offset + ext_len > RDS_HEADER_EXT_SPACE)
172 		goto none;
173 
174 	*pos = offset + ext_len;
175 	if (ext_len < *buflen)
176 		*buflen = ext_len;
177 	memcpy(buf, src + offset, *buflen);
178 	return ext_type;
179 
180 none:
181 	*pos = RDS_HEADER_EXT_SPACE;
182 	*buflen = 0;
183 	return RDS_EXTHDR_NONE;
184 }
185 
186 int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version)
187 {
188 	struct rds_ext_header_version ext_hdr;
189 
190 	ext_hdr.h_version = cpu_to_be32(version);
191 	return rds_message_add_extension(hdr, RDS_EXTHDR_VERSION, &ext_hdr, sizeof(ext_hdr));
192 }
193 
194 int rds_message_get_version_extension(struct rds_header *hdr, unsigned int *version)
195 {
196 	struct rds_ext_header_version ext_hdr;
197 	unsigned int pos = 0, len = sizeof(ext_hdr);
198 
199 	/* We assume the version extension is the only one present */
200 	if (rds_message_next_extension(hdr, &pos, &ext_hdr, &len) != RDS_EXTHDR_VERSION)
201 		return 0;
202 	*version = be32_to_cpu(ext_hdr.h_version);
203 	return 1;
204 }
205 
206 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
207 {
208 	struct rds_ext_header_rdma_dest ext_hdr;
209 
210 	ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
211 	ext_hdr.h_rdma_offset = cpu_to_be32(offset);
212 	return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
213 }
214 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
215 
216 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp)
217 {
218 	struct rds_message *rm;
219 
220 	rm = kzalloc(sizeof(struct rds_message) +
221 		     (nents * sizeof(struct scatterlist)), gfp);
222 	if (!rm)
223 		goto out;
224 
225 	if (nents)
226 		sg_init_table(rm->m_sg, nents);
227 	atomic_set(&rm->m_refcount, 1);
228 	INIT_LIST_HEAD(&rm->m_sock_item);
229 	INIT_LIST_HEAD(&rm->m_conn_item);
230 	spin_lock_init(&rm->m_rs_lock);
231 
232 out:
233 	return rm;
234 }
235 
236 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
237 {
238 	struct rds_message *rm;
239 	unsigned int i;
240 
241 	rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
242 	if (rm == NULL)
243 		return ERR_PTR(-ENOMEM);
244 
245 	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
246 	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
247 	rm->m_nents = ceil(total_len, PAGE_SIZE);
248 
249 	for (i = 0; i < rm->m_nents; ++i) {
250 		sg_set_page(&rm->m_sg[i],
251 				virt_to_page(page_addrs[i]),
252 				PAGE_SIZE, 0);
253 	}
254 
255 	return rm;
256 }
257 
258 struct rds_message *rds_message_copy_from_user(struct iovec *first_iov,
259 					       size_t total_len)
260 {
261 	unsigned long to_copy;
262 	unsigned long iov_off;
263 	unsigned long sg_off;
264 	struct rds_message *rm;
265 	struct iovec *iov;
266 	struct scatterlist *sg;
267 	int ret;
268 
269 	rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
270 	if (rm == NULL) {
271 		ret = -ENOMEM;
272 		goto out;
273 	}
274 
275 	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
276 
277 	/*
278 	 * now allocate and copy in the data payload.
279 	 */
280 	sg = rm->m_sg;
281 	iov = first_iov;
282 	iov_off = 0;
283 	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
284 
285 	while (total_len) {
286 		if (sg_page(sg) == NULL) {
287 			ret = rds_page_remainder_alloc(sg, total_len,
288 						       GFP_HIGHUSER);
289 			if (ret)
290 				goto out;
291 			rm->m_nents++;
292 			sg_off = 0;
293 		}
294 
295 		while (iov_off == iov->iov_len) {
296 			iov_off = 0;
297 			iov++;
298 		}
299 
300 		to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
301 		to_copy = min_t(size_t, to_copy, total_len);
302 
303 		rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
304 			 "sg [%p, %u, %u] + %lu\n",
305 			 to_copy, iov->iov_base, iov->iov_len, iov_off,
306 			 (void *)sg_page(sg), sg->offset, sg->length, sg_off);
307 
308 		ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
309 					      iov->iov_base + iov_off,
310 					      to_copy);
311 		if (ret)
312 			goto out;
313 
314 		iov_off += to_copy;
315 		total_len -= to_copy;
316 		sg_off += to_copy;
317 
318 		if (sg_off == sg->length)
319 			sg++;
320 	}
321 
322 	ret = 0;
323 out:
324 	if (ret) {
325 		if (rm)
326 			rds_message_put(rm);
327 		rm = ERR_PTR(ret);
328 	}
329 	return rm;
330 }
331 
332 int rds_message_inc_copy_to_user(struct rds_incoming *inc,
333 				 struct iovec *first_iov, size_t size)
334 {
335 	struct rds_message *rm;
336 	struct iovec *iov;
337 	struct scatterlist *sg;
338 	unsigned long to_copy;
339 	unsigned long iov_off;
340 	unsigned long vec_off;
341 	int copied;
342 	int ret;
343 	u32 len;
344 
345 	rm = container_of(inc, struct rds_message, m_inc);
346 	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
347 
348 	iov = first_iov;
349 	iov_off = 0;
350 	sg = rm->m_sg;
351 	vec_off = 0;
352 	copied = 0;
353 
354 	while (copied < size && copied < len) {
355 		while (iov_off == iov->iov_len) {
356 			iov_off = 0;
357 			iov++;
358 		}
359 
360 		to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
361 		to_copy = min_t(size_t, to_copy, size - copied);
362 		to_copy = min_t(unsigned long, to_copy, len - copied);
363 
364 		rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
365 			 "sg [%p, %u, %u] + %lu\n",
366 			 to_copy, iov->iov_base, iov->iov_len, iov_off,
367 			 sg_page(sg), sg->offset, sg->length, vec_off);
368 
369 		ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
370 					    iov->iov_base + iov_off,
371 					    to_copy);
372 		if (ret) {
373 			copied = ret;
374 			break;
375 		}
376 
377 		iov_off += to_copy;
378 		vec_off += to_copy;
379 		copied += to_copy;
380 
381 		if (vec_off == sg->length) {
382 			vec_off = 0;
383 			sg++;
384 		}
385 	}
386 
387 	return copied;
388 }
389 
390 /*
391  * If the message is still on the send queue, wait until the transport
392  * is done with it. This is particularly important for RDMA operations.
393  */
394 void rds_message_wait(struct rds_message *rm)
395 {
396 	wait_event(rds_message_flush_waitq,
397 			!test_bit(RDS_MSG_MAPPED, &rm->m_flags));
398 }
399 
400 void rds_message_unmapped(struct rds_message *rm)
401 {
402 	clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
403 	if (waitqueue_active(&rds_message_flush_waitq))
404 		wake_up(&rds_message_flush_waitq);
405 }
406 EXPORT_SYMBOL_GPL(rds_message_unmapped);
407 
408