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 [RDS_EXTHDR_NPATHS] = sizeof(u16), 45 [RDS_EXTHDR_GEN_NUM] = sizeof(u32), 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->data.op_nents; i++) { 67 rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i])); 68 /* XXX will have to put_page for page refs */ 69 __free_page(sg_page(&rm->data.op_sg[i])); 70 } 71 rm->data.op_nents = 0; 72 73 if (rm->rdma.op_active) 74 rds_rdma_free_op(&rm->rdma); 75 if (rm->rdma.op_rdma_mr) 76 rds_mr_put(rm->rdma.op_rdma_mr); 77 78 if (rm->atomic.op_active) 79 rds_atomic_free_op(&rm->atomic); 80 if (rm->atomic.op_rdma_mr) 81 rds_mr_put(rm->atomic.op_rdma_mr); 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 WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm); 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_populate_header(struct rds_header *hdr, __be16 sport, 99 __be16 dport, u64 seq) 100 { 101 hdr->h_flags = 0; 102 hdr->h_sport = sport; 103 hdr->h_dport = dport; 104 hdr->h_sequence = cpu_to_be64(seq); 105 hdr->h_exthdr[0] = RDS_EXTHDR_NONE; 106 } 107 EXPORT_SYMBOL_GPL(rds_message_populate_header); 108 109 int rds_message_add_extension(struct rds_header *hdr, unsigned int type, 110 const void *data, unsigned int len) 111 { 112 unsigned int ext_len = sizeof(u8) + len; 113 unsigned char *dst; 114 115 /* For now, refuse to add more than one extension header */ 116 if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE) 117 return 0; 118 119 if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type]) 120 return 0; 121 122 if (ext_len >= RDS_HEADER_EXT_SPACE) 123 return 0; 124 dst = hdr->h_exthdr; 125 126 *dst++ = type; 127 memcpy(dst, data, len); 128 129 dst[len] = RDS_EXTHDR_NONE; 130 return 1; 131 } 132 EXPORT_SYMBOL_GPL(rds_message_add_extension); 133 134 /* 135 * If a message has extension headers, retrieve them here. 136 * Call like this: 137 * 138 * unsigned int pos = 0; 139 * 140 * while (1) { 141 * buflen = sizeof(buffer); 142 * type = rds_message_next_extension(hdr, &pos, buffer, &buflen); 143 * if (type == RDS_EXTHDR_NONE) 144 * break; 145 * ... 146 * } 147 */ 148 int rds_message_next_extension(struct rds_header *hdr, 149 unsigned int *pos, void *buf, unsigned int *buflen) 150 { 151 unsigned int offset, ext_type, ext_len; 152 u8 *src = hdr->h_exthdr; 153 154 offset = *pos; 155 if (offset >= RDS_HEADER_EXT_SPACE) 156 goto none; 157 158 /* Get the extension type and length. For now, the 159 * length is implied by the extension type. */ 160 ext_type = src[offset++]; 161 162 if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX) 163 goto none; 164 ext_len = rds_exthdr_size[ext_type]; 165 if (offset + ext_len > RDS_HEADER_EXT_SPACE) 166 goto none; 167 168 *pos = offset + ext_len; 169 if (ext_len < *buflen) 170 *buflen = ext_len; 171 memcpy(buf, src + offset, *buflen); 172 return ext_type; 173 174 none: 175 *pos = RDS_HEADER_EXT_SPACE; 176 *buflen = 0; 177 return RDS_EXTHDR_NONE; 178 } 179 180 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset) 181 { 182 struct rds_ext_header_rdma_dest ext_hdr; 183 184 ext_hdr.h_rdma_rkey = cpu_to_be32(r_key); 185 ext_hdr.h_rdma_offset = cpu_to_be32(offset); 186 return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr)); 187 } 188 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension); 189 190 /* 191 * Each rds_message is allocated with extra space for the scatterlist entries 192 * rds ops will need. This is to minimize memory allocation count. Then, each rds op 193 * can grab SGs when initializing its part of the rds_message. 194 */ 195 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp) 196 { 197 struct rds_message *rm; 198 199 if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message)) 200 return NULL; 201 202 rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp); 203 if (!rm) 204 goto out; 205 206 rm->m_used_sgs = 0; 207 rm->m_total_sgs = extra_len / sizeof(struct scatterlist); 208 209 atomic_set(&rm->m_refcount, 1); 210 INIT_LIST_HEAD(&rm->m_sock_item); 211 INIT_LIST_HEAD(&rm->m_conn_item); 212 spin_lock_init(&rm->m_rs_lock); 213 init_waitqueue_head(&rm->m_flush_wait); 214 215 out: 216 return rm; 217 } 218 219 /* 220 * RDS ops use this to grab SG entries from the rm's sg pool. 221 */ 222 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents) 223 { 224 struct scatterlist *sg_first = (struct scatterlist *) &rm[1]; 225 struct scatterlist *sg_ret; 226 227 WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs); 228 WARN_ON(!nents); 229 230 if (rm->m_used_sgs + nents > rm->m_total_sgs) 231 return NULL; 232 233 sg_ret = &sg_first[rm->m_used_sgs]; 234 sg_init_table(sg_ret, nents); 235 rm->m_used_sgs += nents; 236 237 return sg_ret; 238 } 239 240 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len) 241 { 242 struct rds_message *rm; 243 unsigned int i; 244 int num_sgs = ceil(total_len, PAGE_SIZE); 245 int extra_bytes = num_sgs * sizeof(struct scatterlist); 246 247 rm = rds_message_alloc(extra_bytes, GFP_NOWAIT); 248 if (!rm) 249 return ERR_PTR(-ENOMEM); 250 251 set_bit(RDS_MSG_PAGEVEC, &rm->m_flags); 252 rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len); 253 rm->data.op_nents = ceil(total_len, PAGE_SIZE); 254 rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs); 255 if (!rm->data.op_sg) { 256 rds_message_put(rm); 257 return ERR_PTR(-ENOMEM); 258 } 259 260 for (i = 0; i < rm->data.op_nents; ++i) { 261 sg_set_page(&rm->data.op_sg[i], 262 virt_to_page(page_addrs[i]), 263 PAGE_SIZE, 0); 264 } 265 266 return rm; 267 } 268 269 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from) 270 { 271 unsigned long to_copy, nbytes; 272 unsigned long sg_off; 273 struct scatterlist *sg; 274 int ret = 0; 275 276 rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from)); 277 278 /* 279 * now allocate and copy in the data payload. 280 */ 281 sg = rm->data.op_sg; 282 sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */ 283 284 while (iov_iter_count(from)) { 285 if (!sg_page(sg)) { 286 ret = rds_page_remainder_alloc(sg, iov_iter_count(from), 287 GFP_HIGHUSER); 288 if (ret) 289 return ret; 290 rm->data.op_nents++; 291 sg_off = 0; 292 } 293 294 to_copy = min_t(unsigned long, iov_iter_count(from), 295 sg->length - sg_off); 296 297 rds_stats_add(s_copy_from_user, to_copy); 298 nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off, 299 to_copy, from); 300 if (nbytes != to_copy) 301 return -EFAULT; 302 303 sg_off += to_copy; 304 305 if (sg_off == sg->length) 306 sg++; 307 } 308 309 return ret; 310 } 311 312 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to) 313 { 314 struct rds_message *rm; 315 struct scatterlist *sg; 316 unsigned long to_copy; 317 unsigned long vec_off; 318 int copied; 319 int ret; 320 u32 len; 321 322 rm = container_of(inc, struct rds_message, m_inc); 323 len = be32_to_cpu(rm->m_inc.i_hdr.h_len); 324 325 sg = rm->data.op_sg; 326 vec_off = 0; 327 copied = 0; 328 329 while (iov_iter_count(to) && copied < len) { 330 to_copy = min_t(unsigned long, iov_iter_count(to), 331 sg->length - vec_off); 332 to_copy = min_t(unsigned long, to_copy, len - copied); 333 334 rds_stats_add(s_copy_to_user, to_copy); 335 ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off, 336 to_copy, to); 337 if (ret != to_copy) 338 return -EFAULT; 339 340 vec_off += to_copy; 341 copied += to_copy; 342 343 if (vec_off == sg->length) { 344 vec_off = 0; 345 sg++; 346 } 347 } 348 349 return copied; 350 } 351 352 /* 353 * If the message is still on the send queue, wait until the transport 354 * is done with it. This is particularly important for RDMA operations. 355 */ 356 void rds_message_wait(struct rds_message *rm) 357 { 358 wait_event_interruptible(rm->m_flush_wait, 359 !test_bit(RDS_MSG_MAPPED, &rm->m_flags)); 360 } 361 362 void rds_message_unmapped(struct rds_message *rm) 363 { 364 clear_bit(RDS_MSG_MAPPED, &rm->m_flags); 365 wake_up_interruptible(&rm->m_flush_wait); 366 } 367 EXPORT_SYMBOL_GPL(rds_message_unmapped); 368 369