git.oblomov.eu Git - linux-2.6/blob - 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
  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
  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->m_nents; i++) {
  65                 rdsdebug("putting data page %p\n", (void *)sg_page(&rm->m_sg[i]));
  66                 /* XXX will have to put_page for page refs */
  67                 __free_page(sg_page(&rm->m_sg[i]));
  68         }
  69         rm->m_nents = 0;
  70
  71         if (rm->m_rdma_op)
  72                 rds_rdma_free_op(rm->m_rdma_op);
  73         if (rm->m_rdma_mr)
  74                 rds_mr_put(rm->m_rdma_mr);
  75 }
  76
  77 void rds_message_inc_purge(struct rds_incoming *inc)
  78 {
  79         struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
  80         rds_message_purge(rm);
  81 }
  82
  83 void rds_message_put(struct rds_message *rm)
  84 {
  85         rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
  86
  87         if (atomic_dec_and_test(&rm->m_refcount)) {
  88                 BUG_ON(!list_empty(&rm->m_sock_item));
  89                 BUG_ON(!list_empty(&rm->m_conn_item));
  90                 rds_message_purge(rm);
  91
  92                 kfree(rm);
  93         }
  94 }
  95
  96 void rds_message_inc_free(struct rds_incoming *inc)
  97 {
  98         struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
  99         rds_message_put(rm);
 100 }
 101
 102 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
 103                                  __be16 dport, u64 seq)
 104 {
 105         hdr->h_flags = 0;
 106         hdr->h_sport = sport;
 107         hdr->h_dport = dport;
 108         hdr->h_sequence = cpu_to_be64(seq);
 109         hdr->h_exthdr[0] = RDS_EXTHDR_NONE;
 110 }
 111
 112 int rds_message_add_extension(struct rds_header *hdr,
 113                 unsigned int type, const void *data, unsigned int len)
 114 {
 115         unsigned int ext_len = sizeof(u8) + len;
 116         unsigned char *dst;
 117
 118         /* For now, refuse to add more than one extension header */
 119         if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE)
 120                 return 0;
 121
 122         if (type >= __RDS_EXTHDR_MAX
 123          || len != rds_exthdr_size[type])
 124                 return 0;
 125
 126         if (ext_len >= RDS_HEADER_EXT_SPACE)
 127                 return 0;
 128         dst = hdr->h_exthdr;
 129
 130         *dst++ = type;
 131         memcpy(dst, data, len);
 132
 133         dst[len] = RDS_EXTHDR_NONE;
 134         return 1;
 135 }
 136
 137 /*
 138  * If a message has extension headers, retrieve them here.
 139  * Call like this:
 140  *
 141  * unsigned int pos = 0;
 142  *
 143  * while (1) {
 144  *      buflen = sizeof(buffer);
 145  *      type = rds_message_next_extension(hdr, &pos, buffer, &buflen);
 146  *      if (type == RDS_EXTHDR_NONE)
 147  *              break;
 148  *      ...
 149  * }
 150  */
 151 int rds_message_next_extension(struct rds_header *hdr,
 152                 unsigned int *pos, void *buf, unsigned int *buflen)
 153 {
 154         unsigned int offset, ext_type, ext_len;
 155         u8 *src = hdr->h_exthdr;
 156
 157         offset = *pos;
 158         if (offset >= RDS_HEADER_EXT_SPACE)
 159                 goto none;
 160
 161         /* Get the extension type and length. For now, the
 162          * length is implied by the extension type. */
 163         ext_type = src[offset++];
 164
 165         if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX)
 166                 goto none;
 167         ext_len = rds_exthdr_size[ext_type];
 168         if (offset + ext_len > RDS_HEADER_EXT_SPACE)
 169                 goto none;
 170
 171         *pos = offset + ext_len;
 172         if (ext_len < *buflen)
 173                 *buflen = ext_len;
 174         memcpy(buf, src + offset, *buflen);
 175         return ext_type;
 176
 177 none:
 178         *pos = RDS_HEADER_EXT_SPACE;
 179         *buflen = 0;
 180         return RDS_EXTHDR_NONE;
 181 }
 182
 183 int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version)
 184 {
 185         struct rds_ext_header_version ext_hdr;
 186
 187         ext_hdr.h_version = cpu_to_be32(version);
 188         return rds_message_add_extension(hdr, RDS_EXTHDR_VERSION, &ext_hdr, sizeof(ext_hdr));
 189 }
 190
 191 int rds_message_get_version_extension(struct rds_header *hdr, unsigned int *version)
 192 {
 193         struct rds_ext_header_version ext_hdr;
 194         unsigned int pos = 0, len = sizeof(ext_hdr);
 195
 196         /* We assume the version extension is the only one present */
 197         if (rds_message_next_extension(hdr, &pos, &ext_hdr, &len) != RDS_EXTHDR_VERSION)
 198                 return 0;
 199         *version = be32_to_cpu(ext_hdr.h_version);
 200         return 1;
 201 }
 202
 203 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset)
 204 {
 205         struct rds_ext_header_rdma_dest ext_hdr;
 206
 207         ext_hdr.h_rdma_rkey = cpu_to_be32(r_key);
 208         ext_hdr.h_rdma_offset = cpu_to_be32(offset);
 209         return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr));
 210 }
 211
 212 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp)
 213 {
 214         struct rds_message *rm;
 215
 216         rm = kzalloc(sizeof(struct rds_message) +
 217                      (nents * sizeof(struct scatterlist)), gfp);
 218         if (!rm)
 219                 goto out;
 220
 221         if (nents)
 222                 sg_init_table(rm->m_sg, nents);
 223         atomic_set(&rm->m_refcount, 1);
 224         INIT_LIST_HEAD(&rm->m_sock_item);
 225         INIT_LIST_HEAD(&rm->m_conn_item);
 226         spin_lock_init(&rm->m_rs_lock);
 227
 228 out:
 229         return rm;
 230 }
 231
 232 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len)
 233 {
 234         struct rds_message *rm;
 235         unsigned int i;
 236
 237         rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
 238         if (rm == NULL)
 239                 return ERR_PTR(-ENOMEM);
 240
 241         set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
 242         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
 243         rm->m_nents = ceil(total_len, PAGE_SIZE);
 244
 245         for (i = 0; i < rm->m_nents; ++i) {
 246                 sg_set_page(&rm->m_sg[i],
 247                                 virt_to_page(page_addrs[i]),
 248                                 PAGE_SIZE, 0);
 249         }
 250
 251         return rm;
 252 }
 253
 254 struct rds_message *rds_message_copy_from_user(struct iovec *first_iov,
 255                                                size_t total_len)
 256 {
 257         unsigned long to_copy;
 258         unsigned long iov_off;
 259         unsigned long sg_off;
 260         struct rds_message *rm;
 261         struct iovec *iov;
 262         struct scatterlist *sg;
 263         int ret;
 264
 265         rm = rds_message_alloc(ceil(total_len, PAGE_SIZE), GFP_KERNEL);
 266         if (rm == NULL) {
 267                 ret = -ENOMEM;
 268                 goto out;
 269         }
 270
 271         rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
 272
 273         /*
 274          * now allocate and copy in the data payload.
 275          */
 276         sg = rm->m_sg;
 277         iov = first_iov;
 278         iov_off = 0;
 279         sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
 280
 281         while (total_len) {
 282                 if (sg_page(sg) == NULL) {
 283                         ret = rds_page_remainder_alloc(sg, total_len,
 284                                                        GFP_HIGHUSER);
 285                         if (ret)
 286                                 goto out;
 287                         rm->m_nents++;
 288                         sg_off = 0;
 289                 }
 290
 291                 while (iov_off == iov->iov_len) {
 292                         iov_off = 0;
 293                         iov++;
 294                 }
 295
 296                 to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
 297                 to_copy = min_t(size_t, to_copy, total_len);
 298
 299                 rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
 300                          "sg [%p, %u, %u] + %lu\n",
 301                          to_copy, iov->iov_base, iov->iov_len, iov_off,
 302                          (void *)sg_page(sg), sg->offset, sg->length, sg_off);
 303
 304                 ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
 305                                               iov->iov_base + iov_off,
 306                                               to_copy);
 307                 if (ret)
 308                         goto out;
 309
 310                 iov_off += to_copy;
 311                 total_len -= to_copy;
 312                 sg_off += to_copy;
 313
 314                 if (sg_off == sg->length)
 315                         sg++;
 316         }
 317
 318         ret = 0;
 319 out:
 320         if (ret) {
 321                 if (rm)
 322                         rds_message_put(rm);
 323                 rm = ERR_PTR(ret);
 324         }
 325         return rm;
 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->m_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(rds_message_flush_waitq,
 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         if (waitqueue_active(&rds_message_flush_waitq))
 400                 wake_up(&rds_message_flush_waitq);
 401 }
 402