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->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
  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 struct 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
 233 out:
 234         return rm;
 235 }
 236
 237 struct 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
 259 struct 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;
 324 out:
 325         if (ret) {
 326                 if (rm)
 327                         rds_message_put(rm);
 328                 rm = ERR_PTR(ret);
 329         }
 330         return rm;
 331 }
 332
 333 int 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  */
 395 void 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
 401 void 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 }
 407 EXPORT_SYMBOL_GPL(rds_message_unmapped);
 408