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 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