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 }; 45 46 47 void rds_message_addref(struct rds_message *rm) 48 { 49 rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount)); 50 atomic_inc(&rm->m_refcount); 51 } 52 EXPORT_SYMBOL_GPL(rds_message_addref); 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->data.op_nents; i++) { 65 rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i])); 66 /* XXX will have to put_page for page refs */ 67 __free_page(sg_page(&rm->data.op_sg[i])); 68 } 69 rm->data.op_nents = 0; 70 71 if (rm->rdma.op_active) 72 rds_rdma_free_op(&rm->rdma); 73 if (rm->rdma.op_rdma_mr) 74 rds_mr_put(rm->rdma.op_rdma_mr); 75 76 if (rm->atomic.op_active) 77 rds_atomic_free_op(&rm->atomic); 78 if (rm->atomic.op_rdma_mr) 79 rds_mr_put(rm->atomic.op_rdma_mr); 80 } 81 82 void rds_message_put(struct rds_message *rm) 83 { 84 rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount)); 85 WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm); 86 if (atomic_dec_and_test(&rm->m_refcount)) { 87 BUG_ON(!list_empty(&rm->m_sock_item)); 88 BUG_ON(!list_empty(&rm->m_conn_item)); 89 rds_message_purge(rm); 90 91 kfree(rm); 92 } 93 } 94 EXPORT_SYMBOL_GPL(rds_message_put); 95 96 void rds_message_populate_header(struct rds_header *hdr, __be16 sport, 97 __be16 dport, u64 seq) 98 { 99 hdr->h_flags = 0; 100 hdr->h_sport = sport; 101 hdr->h_dport = dport; 102 hdr->h_sequence = cpu_to_be64(seq); 103 hdr->h_exthdr[0] = RDS_EXTHDR_NONE; 104 } 105 EXPORT_SYMBOL_GPL(rds_message_populate_header); 106 107 int rds_message_add_extension(struct rds_header *hdr, unsigned int type, 108 const void *data, unsigned int len) 109 { 110 unsigned int ext_len = sizeof(u8) + len; 111 unsigned char *dst; 112 113 /* For now, refuse to add more than one extension header */ 114 if (hdr->h_exthdr[0] != RDS_EXTHDR_NONE) 115 return 0; 116 117 if (type >= __RDS_EXTHDR_MAX || len != rds_exthdr_size[type]) 118 return 0; 119 120 if (ext_len >= RDS_HEADER_EXT_SPACE) 121 return 0; 122 dst = hdr->h_exthdr; 123 124 *dst++ = type; 125 memcpy(dst, data, len); 126 127 dst[len] = RDS_EXTHDR_NONE; 128 return 1; 129 } 130 EXPORT_SYMBOL_GPL(rds_message_add_extension); 131 132 /* 133 * If a message has extension headers, retrieve them here. 134 * Call like this: 135 * 136 * unsigned int pos = 0; 137 * 138 * while (1) { 139 * buflen = sizeof(buffer); 140 * type = rds_message_next_extension(hdr, &pos, buffer, &buflen); 141 * if (type == RDS_EXTHDR_NONE) 142 * break; 143 * ... 144 * } 145 */ 146 int rds_message_next_extension(struct rds_header *hdr, 147 unsigned int *pos, void *buf, unsigned int *buflen) 148 { 149 unsigned int offset, ext_type, ext_len; 150 u8 *src = hdr->h_exthdr; 151 152 offset = *pos; 153 if (offset >= RDS_HEADER_EXT_SPACE) 154 goto none; 155 156 /* Get the extension type and length. For now, the 157 * length is implied by the extension type. */ 158 ext_type = src[offset++]; 159 160 if (ext_type == RDS_EXTHDR_NONE || ext_type >= __RDS_EXTHDR_MAX) 161 goto none; 162 ext_len = rds_exthdr_size[ext_type]; 163 if (offset + ext_len > RDS_HEADER_EXT_SPACE) 164 goto none; 165 166 *pos = offset + ext_len; 167 if (ext_len < *buflen) 168 *buflen = ext_len; 169 memcpy(buf, src + offset, *buflen); 170 return ext_type; 171 172 none: 173 *pos = RDS_HEADER_EXT_SPACE; 174 *buflen = 0; 175 return RDS_EXTHDR_NONE; 176 } 177 178 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset) 179 { 180 struct rds_ext_header_rdma_dest ext_hdr; 181 182 ext_hdr.h_rdma_rkey = cpu_to_be32(r_key); 183 ext_hdr.h_rdma_offset = cpu_to_be32(offset); 184 return rds_message_add_extension(hdr, RDS_EXTHDR_RDMA_DEST, &ext_hdr, sizeof(ext_hdr)); 185 } 186 EXPORT_SYMBOL_GPL(rds_message_add_rdma_dest_extension); 187 188 /* 189 * Each rds_message is allocated with extra space for the scatterlist entries 190 * rds ops will need. This is to minimize memory allocation count. Then, each rds op 191 * can grab SGs when initializing its part of the rds_message. 192 */ 193 struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp) 194 { 195 struct rds_message *rm; 196 197 if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message)) 198 return NULL; 199 200 rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp); 201 if (!rm) 202 goto out; 203 204 rm->m_used_sgs = 0; 205 rm->m_total_sgs = extra_len / sizeof(struct scatterlist); 206 207 atomic_set(&rm->m_refcount, 1); 208 INIT_LIST_HEAD(&rm->m_sock_item); 209 INIT_LIST_HEAD(&rm->m_conn_item); 210 spin_lock_init(&rm->m_rs_lock); 211 init_waitqueue_head(&rm->m_flush_wait); 212 213 out: 214 return rm; 215 } 216 217 /* 218 * RDS ops use this to grab SG entries from the rm's sg pool. 219 */ 220 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents) 221 { 222 struct scatterlist *sg_first = (struct scatterlist *) &rm[1]; 223 struct scatterlist *sg_ret; 224 225 WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs); 226 WARN_ON(!nents); 227 228 if (rm->m_used_sgs + nents > rm->m_total_sgs) 229 return NULL; 230 231 sg_ret = &sg_first[rm->m_used_sgs]; 232 sg_init_table(sg_ret, nents); 233 rm->m_used_sgs += nents; 234 235 return sg_ret; 236 } 237 238 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len) 239 { 240 struct rds_message *rm; 241 unsigned int i; 242 int num_sgs = ceil(total_len, PAGE_SIZE); 243 int extra_bytes = num_sgs * sizeof(struct scatterlist); 244 245 rm = rds_message_alloc(extra_bytes, GFP_NOWAIT); 246 if (!rm) 247 return ERR_PTR(-ENOMEM); 248 249 set_bit(RDS_MSG_PAGEVEC, &rm->m_flags); 250 rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len); 251 rm->data.op_nents = ceil(total_len, PAGE_SIZE); 252 rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs); 253 if (!rm->data.op_sg) { 254 rds_message_put(rm); 255 return ERR_PTR(-ENOMEM); 256 } 257 258 for (i = 0; i < rm->data.op_nents; ++i) { 259 sg_set_page(&rm->data.op_sg[i], 260 virt_to_page(page_addrs[i]), 261 PAGE_SIZE, 0); 262 } 263 264 return rm; 265 } 266 267 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from) 268 { 269 unsigned long to_copy, nbytes; 270 unsigned long sg_off; 271 struct scatterlist *sg; 272 int ret = 0; 273 274 rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from)); 275 276 /* 277 * now allocate and copy in the data payload. 278 */ 279 sg = rm->data.op_sg; 280 sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */ 281 282 while (iov_iter_count(from)) { 283 if (!sg_page(sg)) { 284 ret = rds_page_remainder_alloc(sg, iov_iter_count(from), 285 GFP_HIGHUSER); 286 if (ret) 287 return ret; 288 rm->data.op_nents++; 289 sg_off = 0; 290 } 291 292 to_copy = min_t(unsigned long, iov_iter_count(from), 293 sg->length - sg_off); 294 295 rds_stats_add(s_copy_from_user, to_copy); 296 nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off, 297 to_copy, from); 298 if (nbytes != to_copy) 299 return -EFAULT; 300 301 sg_off += to_copy; 302 303 if (sg_off == sg->length) 304 sg++; 305 } 306 307 return ret; 308 } 309 310 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to) 311 { 312 struct rds_message *rm; 313 struct scatterlist *sg; 314 unsigned long to_copy; 315 unsigned long vec_off; 316 int copied; 317 int ret; 318 u32 len; 319 320 rm = container_of(inc, struct rds_message, m_inc); 321 len = be32_to_cpu(rm->m_inc.i_hdr.h_len); 322 323 sg = rm->data.op_sg; 324 vec_off = 0; 325 copied = 0; 326 327 while (iov_iter_count(to) && copied < len) { 328 to_copy = min_t(unsigned long, iov_iter_count(to), 329 sg->length - vec_off); 330 to_copy = min_t(unsigned long, to_copy, len - copied); 331 332 rds_stats_add(s_copy_to_user, to_copy); 333 ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off, 334 to_copy, to); 335 if (ret != to_copy) 336 return -EFAULT; 337 338 vec_off += to_copy; 339 copied += to_copy; 340 341 if (vec_off == sg->length) { 342 vec_off = 0; 343 sg++; 344 } 345 } 346 347 return copied; 348 } 349 350 /* 351 * If the message is still on the send queue, wait until the transport 352 * is done with it. This is particularly important for RDMA operations. 353 */ 354 void rds_message_wait(struct rds_message *rm) 355 { 356 wait_event_interruptible(rm->m_flush_wait, 357 !test_bit(RDS_MSG_MAPPED, &rm->m_flags)); 358 } 359 360 void rds_message_unmapped(struct rds_message *rm) 361 { 362 clear_bit(RDS_MSG_MAPPED, &rm->m_flags); 363 wake_up_interruptible(&rm->m_flush_wait); 364 } 365 EXPORT_SYMBOL_GPL(rds_message_unmapped); 366 367