3498cbcc7542752af3d42c68d886c151fdde79df
[linux-3.10.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
36 #include "rds.h"
37 #include "rdma.h"
38
39 static DECLARE_WAIT_QUEUE_HEAD(rds_message_flush_waitq);
40
41 static unsigned int     rds_exthdr_size[__RDS_EXTHDR_MAX] = {
42 [RDS_EXTHDR_NONE]       = 0,
43 [RDS_EXTHDR_VERSION]    = sizeof(struct rds_ext_header_version),
44 [RDS_EXTHDR_RDMA]       = sizeof(struct rds_ext_header_rdma),
45 [RDS_EXTHDR_RDMA_DEST]  = sizeof(struct rds_ext_header_rdma_dest),
46 };
47
48
49 void rds_message_addref(struct rds_message *rm)
50 {
51         rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
52         atomic_inc(&rm->m_refcount);
53 }
54 EXPORT_SYMBOL_GPL(rds_message_addref);
55
56 /*
57  * This relies on dma_map_sg() not touching sg[].page during merging.
58  */
59 static void rds_message_purge(struct rds_message *rm)
60 {
61         unsigned long i;
62
63         if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
64                 return;
65
66         for (i = 0; i < rm->data.m_nents; i++) {
67                 rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.m_sg[i]));
68                 /* XXX will have to put_page for page refs */
69                 __free_page(sg_page(&rm->data.m_sg[i]));
70         }
71         rm->data.m_nents = 0;
72
73         if (rm->rdma.m_rdma_op)
74                 rds_rdma_free_op(rm->rdma.m_rdma_op);
75         if (rm->rdma.m_rdma_mr)
76                 rds_mr_put(rm->rdma.m_rdma_mr);
77 }
78
79 void rds_message_inc_purge(struct rds_incoming *inc)
80 {
81         struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
82         rds_message_purge(rm);
83 }
84
85 void rds_message_put(struct rds_message *rm)
86 {
87         rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
88
89         if (atomic_dec_and_test(&rm->m_refcount)) {
90                 BUG_ON(!list_empty(&rm->m_sock_item));
91                 BUG_ON(!list_empty(&rm->m_conn_item));
92                 rds_message_purge(rm);
93
94                 kfree(rm);
95         }
96 }
97 EXPORT_SYMBOL_GPL(rds_message_put);
98
99 void rds_message_inc_free(struct rds_incoming *inc)
100 {
101         struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
102         rds_message_put(rm);
103 }
104
105 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
106                                  __be16 dport, u64 seq)
107 {
108         hdr->h_flags = 0;
109         hdr->h_sport = sport;
110         hdr->h_dport = dport;
111         hdr->h_sequence = cpu_to_be64(seq);
112         hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
113 }
114 EXPORT_SYMBOL_GPL(rds_message_populate_header);
115
116 int rds_message_add_extension(struct rds_header *hdr,
117                 unsigned int type, const void *data, unsigned int len)
118 {
119         unsigned int ext_len = sizeof(u8) + len;
120         unsigned char *dst;
121
122         /* For now, refuse to add more than one extension header */
123         if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
124                 return 0;
125
126         if (type >= __RDS_EXTHDR_MAX || 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 /*
218  * Each rds_message is allocated with extra space for the scatterlist entries
219  * rds ops will need. This is to minimize memory allocation count. Then, each rds op
220  * can grab SGs when initializing its part of the rds_message.
221  */
222 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
223 {
224         struct rds_message *rm;
225
226         rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
227         if (!rm)
228                 goto out;
229
230         rm->m_used_sgs = 0;
231         rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
232
233         atomic_set(&rm->m_refcount, 1);
234         INIT_LIST_HEAD(&rm->m_sock_item);
235         INIT_LIST_HEAD(&rm->m_conn_item);
236         spin_lock_init(&rm->m_rs_lock);
237
238 out:
239         return rm;
240 }
241
242 /*
243  * RDS ops use this to grab SG entries from the rm's sg pool.
244  */
245 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
246 {
247         struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
248         struct scatterlist *sg_ret;
249
250         WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
251
252         sg_ret = &sg_first[rm->m_used_sgs];
253
254         rm->m_used_sgs += nents;
255
256         return sg_ret;
257 }
258
259 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
260 {
261         struct rds_message *rm;
262         unsigned int i;
263
264         rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
265         if (!rm)
266                 return ERR_PTR(-ENOMEM);
267
268         set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
269         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
270         rm->data.m_nents = ceil(total_len, PAGE_SIZE);
271
272         for (i = 0; i < rm->data.m_nents; ++i) {
273                 sg_set_page(&rm->data.m_sg[i],
274                                 virt_to_page(page_addrs[i]),
275                                 PAGE_SIZE, 0);
276         }
277
278         return rm;
279 }
280
281 int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
282                                                size_t total_len)
283 {
284         unsigned long to_copy;
285         unsigned long iov_off;
286         unsigned long sg_off;
287         struct iovec *iov;
288         struct scatterlist *sg;
289         int ret = 0;
290
291         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
292
293         /*
294          * now allocate and copy in the data payload.
295          */
296         sg = rm->data.m_sg;
297         iov = first_iov;
298         iov_off = 0;
299         sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
300
301         while (total_len) {
302                 if (!sg_page(sg)) {
303                         ret = rds_page_remainder_alloc(sg, total_len,
304                                                        GFP_HIGHUSER);
305                         if (ret)
306                                 goto out;
307                         rm->data.m_nents++;
308                         sg_off = 0;
309                 }
310
311                 while (iov_off == iov->iov_len) {
312                         iov_off = 0;
313                         iov++;
314                 }
315
316                 to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
317                 to_copy = min_t(size_t, to_copy, total_len);
318
319                 rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
320                          "sg [%p, %u, %u] + %lu\n",
321                          to_copy, iov->iov_base, iov->iov_len, iov_off,
322                          (void *)sg_page(sg), sg->offset, sg->length, sg_off);
323
324                 ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
325                                               iov->iov_base + iov_off,
326                                               to_copy);
327                 if (ret)
328                         goto out;
329
330                 iov_off += to_copy;
331                 total_len -= to_copy;
332                 sg_off += to_copy;
333
334                 if (sg_off == sg->length)
335                         sg++;
336         }
337
338 out:
339         return ret;
340 }
341
342 int rds_message_inc_copy_to_user(struct rds_incoming *inc,
343                                  struct iovec *first_iov, size_t size)
344 {
345         struct rds_message *rm;
346         struct iovec *iov;
347         struct scatterlist *sg;
348         unsigned long to_copy;
349         unsigned long iov_off;
350         unsigned long vec_off;
351         int copied;
352         int ret;
353         u32 len;
354
355         rm = container_of(inc, struct rds_message, m_inc);
356         len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
357
358         iov = first_iov;
359         iov_off = 0;
360         sg = rm->data.m_sg;
361         vec_off = 0;
362         copied = 0;
363
364         while (copied < size && copied < len) {
365                 while (iov_off == iov->iov_len) {
366                         iov_off = 0;
367                         iov++;
368                 }
369
370                 to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
371                 to_copy = min_t(size_t, to_copy, size - copied);
372                 to_copy = min_t(unsigned long, to_copy, len - copied);
373
374                 rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
375                          "sg [%p, %u, %u] + %lu\n",
376                          to_copy, iov->iov_base, iov->iov_len, iov_off,
377                          sg_page(sg), sg->offset, sg->length, vec_off);
378
379                 ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
380                                             iov->iov_base + iov_off,
381                                             to_copy);
382                 if (ret) {
383                         copied = ret;
384                         break;
385                 }
386
387                 iov_off += to_copy;
388                 vec_off += to_copy;
389                 copied += to_copy;
390
391                 if (vec_off == sg->length) {
392                         vec_off = 0;
393                         sg++;
394                 }
395         }
396
397         return copied;
398 }
399
400 /*
401  * If the message is still on the send queue, wait until the transport
402  * is done with it. This is particularly important for RDMA operations.
403  */
404 void rds_message_wait(struct rds_message *rm)
405 {
406         wait_event(rds_message_flush_waitq,
407                         !test_bit(RDS_MSG_MAPPED, &rm->m_flags));
408 }
409
410 void rds_message_unmapped(struct rds_message *rm)
411 {
412         clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
413         if (waitqueue_active(&rds_message_flush_waitq))
414                 wake_up(&rds_message_flush_waitq);
415 }
416 EXPORT_SYMBOL_GPL(rds_message_unmapped);
417