Root/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
39static DECLARE_WAIT_QUEUE_HEAD(rds_message_flush_waitq);
40
41static 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
49void 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}
54EXPORT_SYMBOL_GPL(rds_message_addref);
55
56/*
57 * This relies on dma_map_sg() not touching sg[].page during merging.
58 */
59static 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->m_nents; i++) {
67        rdsdebug("putting data page %p\n", (void *)sg_page(&rm->m_sg[i]));
68        /* XXX will have to put_page for page refs */
69        __free_page(sg_page(&rm->m_sg[i]));
70    }
71    rm->m_nents = 0;
72
73    if (rm->m_rdma_op)
74        rds_rdma_free_op(rm->m_rdma_op);
75    if (rm->m_rdma_mr)
76        rds_mr_put(rm->m_rdma_mr);
77}
78
79void 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
85void 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}
97EXPORT_SYMBOL_GPL(rds_message_put);
98
99void 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
105void 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}
114EXPORT_SYMBOL_GPL(rds_message_populate_header);
115
116int 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}
139EXPORT_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 */
155int 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
181none:
182    *pos = RDS_HEADER_EXT_SPACE;
183    *buflen = 0;
184    return RDS_EXTHDR_NONE;
185}
186
187int 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
195int 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
207int 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}
215EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension);
216
217struct 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
233out:
234    return rm;
235}
236
237struct 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
259struct 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;
324out:
325    if (ret) {
326        if (rm)
327            rds_message_put(rm);
328        rm = ERR_PTR(ret);
329    }
330    return rm;
331}
332
333int 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 */
395void 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
401void 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}
407EXPORT_SYMBOL_GPL(rds_message_unmapped);
408
409

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