Merge remote-tracking branch 'regulator/topic/gpio' into v3.9-rc8
[platform/adaptation/renesas_rcar/renesas_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 };
45
46
47 void rds_message_addref(struct rds_message *rm)
48 {
49         rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
50         atomic_inc(&rm->m_refcount);
51 }
52 EXPORT_SYMBOL_GPL(rds_message_addref);
53
54 /*
55  * This relies on dma_map_sg() not touching sg[].page during merging.
56  */
57 static void rds_message_purge(struct rds_message *rm)
58 {
59         unsigned long i;
60
61         if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
62                 return;
63
64         for (i = 0; i < rm->data.op_nents; i++) {
65                 rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i]));
66                 /* XXX will have to put_page for page refs */
67                 __free_page(sg_page(&rm->data.op_sg[i]));
68         }
69         rm->data.op_nents = 0;
70
71         if (rm->rdma.op_active)
72                 rds_rdma_free_op(&rm->rdma);
73         if (rm->rdma.op_rdma_mr)
74                 rds_mr_put(rm->rdma.op_rdma_mr);
75
76         if (rm->atomic.op_active)
77                 rds_atomic_free_op(&rm->atomic);
78         if (rm->atomic.op_rdma_mr)
79                 rds_mr_put(rm->atomic.op_rdma_mr);
80 }
81
82 void rds_message_put(struct rds_message *rm)
83 {
84         rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
85         WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
86         if (atomic_dec_and_test(&rm->m_refcount)) {
87                 BUG_ON(!list_empty(&rm->m_sock_item));
88                 BUG_ON(!list_empty(&rm->m_conn_item));
89                 rds_message_purge(rm);
90
91                 kfree(rm);
92         }
93 }
94 EXPORT_SYMBOL_GPL(rds_message_put);
95
96 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
97                                  __be16 dport, u64 seq)
98 {
99         hdr->h_flags = 0;
100         hdr->h_sport = sport;
101         hdr->h_dport = dport;
102         hdr->h_sequence = cpu_to_be64(seq);
103         hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
104 }
105 EXPORT_SYMBOL_GPL(rds_message_populate_header);
106
107 int rds_message_add_extension(struct rds_header *hdr, unsigned int type,
108                               const void *data, unsigned int len)
109 {
110         unsigned int ext_len = sizeof(u8) + len;
111         unsigned char *dst;
112
113         /* For now, refuse to add more than one extension header */
114         if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
115                 return 0;
116
117         if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type])
118                 return 0;
119
120         if (ext_len >= RDS_HEADER_EXT_SPACE)
121                 return 0;
122         dst = hdr->h_exthdr;
123
124         *dst++ = type;
125         memcpy(dst, data, len);
126
127         dst[len] = RDS_EXTHDR_NONE;
128         return 1;
129 }
130 EXPORT_SYMBOL_GPL(rds_message_add_extension);
131
132 /*
133  * If a message has extension headers, retrieve them here.
134  * Call like this:
135  *
136  * unsigned int pos = 0;
137  *
138  * while (1) {
139  *      buflen = sizeof(buffer);
140  *      type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
141  *      if (type == RDS_EXTHDR_NONE)
142  *              break;
143  *      ...
144  * }
145  */
146 int rds_message_next_extension(struct rds_header *hdr,
147                 unsigned int *pos, void *buf, unsigned int *buflen)
148 {
149         unsigned int offset, ext_type, ext_len;
150         u8 *src = hdr->h_exthdr;
151
152         offset = *pos;
153         if (offset >= RDS_HEADER_EXT_SPACE)
154                 goto none;
155
156         /* Get the extension type and length. For now, the
157          * length is implied by the extension type. */
158         ext_type = src[offset++];
159
160         if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
161                 goto none;
162         ext_len = rds_exthdr_size[ext_type];
163         if (offset + ext_len > RDS_HEADER_EXT_SPACE)
164                 goto none;
165
166         *pos = offset + ext_len;
167         if (ext_len < *buflen)
168                 *buflen = ext_len;
169         memcpy(buf, src + offset, *buflen);
170         return ext_type;
171
172 none:
173         *pos = RDS_HEADER_EXT_SPACE;
174         *buflen = 0;
175         return RDS_EXTHDR_NONE;
176 }
177
178 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
179 {
180         struct rds_ext_header_rdma_dest ext_hdr;
181
182         ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
183         ext_hdr.h_rdma_offset = cpu_to_be32(offset);
184         return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
185 }
186 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
187
188 /*
189  * Each rds_message is allocated with extra space for the scatterlist entries
190  * rds ops will need. This is to minimize memory allocation count. Then, each rds op
191  * can grab SGs when initializing its part of the rds_message.
192  */
193 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
194 {
195         struct rds_message *rm;
196
197         if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message))
198                 return NULL;
199
200         rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp);
201         if (!rm)
202                 goto out;
203
204         rm->m_used_sgs = 0;
205         rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
206
207         atomic_set(&rm->m_refcount, 1);
208         INIT_LIST_HEAD(&rm->m_sock_item);
209         INIT_LIST_HEAD(&rm->m_conn_item);
210         spin_lock_init(&rm->m_rs_lock);
211         init_waitqueue_head(&rm->m_flush_wait);
212
213 out:
214         return rm;
215 }
216
217 /*
218  * RDS ops use this to grab SG entries from the rm's sg pool.
219  */
220 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
221 {
222         struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
223         struct scatterlist *sg_ret;
224
225         WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
226         WARN_ON(!nents);
227
228         if (rm->m_used_sgs + nents > rm->m_total_sgs)
229                 return NULL;
230
231         sg_ret = &sg_first[rm->m_used_sgs];
232         sg_init_table(sg_ret, nents);
233         rm->m_used_sgs += nents;
234
235         return sg_ret;
236 }
237
238 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
239 {
240         struct rds_message *rm;
241         unsigned int i;
242         int num_sgs = ceil(total_len, PAGE_SIZE);
243         int extra_bytes = num_sgs * sizeof(struct scatterlist);
244
245         rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
246         if (!rm)
247                 return ERR_PTR(-ENOMEM);
248
249         set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
250         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
251         rm->data.op_nents = ceil(total_len, PAGE_SIZE);
252         rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
253         if (!rm->data.op_sg) {
254                 rds_message_put(rm);
255                 return ERR_PTR(-ENOMEM);
256         }
257
258         for (i = 0; i < rm->data.op_nents; ++i) {
259                 sg_set_page(&rm->data.op_sg[i],
260                                 virt_to_page(page_addrs[i]),
261                                 PAGE_SIZE, 0);
262         }
263
264         return rm;
265 }
266
267 int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
268                                                size_t total_len)
269 {
270         unsigned long to_copy;
271         unsigned long iov_off;
272         unsigned long sg_off;
273         struct iovec *iov;
274         struct scatterlist *sg;
275         int ret = 0;
276
277         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
278
279         /*
280          * now allocate and copy in the data payload.
281          */
282         sg = rm->data.op_sg;
283         iov = first_iov;
284         iov_off = 0;
285         sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
286
287         while (total_len) {
288                 if (!sg_page(sg)) {
289                         ret = rds_page_remainder_alloc(sg, total_len,
290                                                        GFP_HIGHUSER);
291                         if (ret)
292                                 goto out;
293                         rm->data.op_nents++;
294                         sg_off = 0;
295                 }
296
297                 while (iov_off == iov->iov_len) {
298                         iov_off = 0;
299                         iov++;
300                 }
301
302                 to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
303                 to_copy = min_t(size_t, to_copy, total_len);
304
305                 rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
306                          "sg [%p, %u, %u] + %lu\n",
307                          to_copy, iov->iov_base, iov->iov_len, iov_off,
308                          (void *)sg_page(sg), sg->offset, sg->length, sg_off);
309
310                 ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
311                                               iov->iov_base + iov_off,
312                                               to_copy);
313                 if (ret)
314                         goto out;
315
316                 iov_off += to_copy;
317                 total_len -= to_copy;
318                 sg_off += to_copy;
319
320                 if (sg_off == sg->length)
321                         sg++;
322         }
323
324 out:
325         return ret;
326 }
327
328 int rds_message_inc_copy_to_user(struct rds_incoming *inc,
329                                  struct iovec *first_iov, size_t size)
330 {
331         struct rds_message *rm;
332         struct iovec *iov;
333         struct scatterlist *sg;
334         unsigned long to_copy;
335         unsigned long iov_off;
336         unsigned long vec_off;
337         int copied;
338         int ret;
339         u32 len;
340
341         rm = container_of(inc, struct rds_message, m_inc);
342         len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
343
344         iov = first_iov;
345         iov_off = 0;
346         sg = rm->data.op_sg;
347         vec_off = 0;
348         copied = 0;
349
350         while (copied < size && copied < len) {
351                 while (iov_off == iov->iov_len) {
352                         iov_off = 0;
353                         iov++;
354                 }
355
356                 to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
357                 to_copy = min_t(size_t, to_copy, size - copied);
358                 to_copy = min_t(unsigned long, to_copy, len - copied);
359
360                 rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
361                          "sg [%p, %u, %u] + %lu\n",
362                          to_copy, iov->iov_base, iov->iov_len, iov_off,
363                          sg_page(sg), sg->offset, sg->length, vec_off);
364
365                 ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
366                                             iov->iov_base + iov_off,
367                                             to_copy);
368                 if (ret) {
369                         copied = ret;
370                         break;
371                 }
372
373                 iov_off += to_copy;
374                 vec_off += to_copy;
375                 copied += to_copy;
376
377                 if (vec_off == sg->length) {
378                         vec_off = 0;
379                         sg++;
380                 }
381         }
382
383         return copied;
384 }
385
386 /*
387  * If the message is still on the send queue, wait until the transport
388  * is done with it. This is particularly important for RDMA operations.
389  */
390 void rds_message_wait(struct rds_message *rm)
391 {
392         wait_event_interruptible(rm->m_flush_wait,
393                         !test_bit(RDS_MSG_MAPPED, &rm->m_flags));
394 }
395
396 void rds_message_unmapped(struct rds_message *rm)
397 {
398         clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
399         wake_up_interruptible(&rm->m_flush_wait);
400 }
401 EXPORT_SYMBOL_GPL(rds_message_unmapped);
402