1 /* 2 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. 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 #include <linux/module.h> 33 #include <linux/kernel.h> 34 #include <linux/slab.h> 35 #include <linux/mm.h> 36 #include <linux/highmem.h> 37 #include <linux/scatterlist.h> 38 39 #include "iscsi_iser.h" 40 41 #define ISER_KMALLOC_THRESHOLD 0x20000 /* 128K - kmalloc limit */ 42 43 /** 44 * Decrements the reference count for the 45 * registered buffer & releases it 46 * 47 * returns 0 if released, 1 if deferred 48 */ 49 int iser_regd_buff_release(struct iser_regd_buf *regd_buf) 50 { 51 struct ib_device *dev; 52 53 if ((atomic_read(®d_buf->ref_count) == 0) || 54 atomic_dec_and_test(®d_buf->ref_count)) { 55 /* if we used the dma mr, unreg is just NOP */ 56 if (regd_buf->reg.is_fmr) 57 iser_unreg_mem(®d_buf->reg); 58 59 if (regd_buf->dma_addr) { 60 dev = regd_buf->device->ib_device; 61 ib_dma_unmap_single(dev, 62 regd_buf->dma_addr, 63 regd_buf->data_size, 64 regd_buf->direction); 65 } 66 /* else this regd buf is associated with task which we */ 67 /* dma_unmap_single/sg later */ 68 return 0; 69 } else { 70 iser_dbg("Release deferred, regd.buff: 0x%p\n", regd_buf); 71 return 1; 72 } 73 } 74 75 /** 76 * iser_reg_single - fills registered buffer descriptor with 77 * registration information 78 */ 79 void iser_reg_single(struct iser_device *device, 80 struct iser_regd_buf *regd_buf, 81 enum dma_data_direction direction) 82 { 83 u64 dma_addr; 84 85 dma_addr = ib_dma_map_single(device->ib_device, 86 regd_buf->virt_addr, 87 regd_buf->data_size, direction); 88 BUG_ON(ib_dma_mapping_error(device->ib_device, dma_addr)); 89 90 regd_buf->reg.lkey = device->mr->lkey; 91 regd_buf->reg.len = regd_buf->data_size; 92 regd_buf->reg.va = dma_addr; 93 regd_buf->reg.is_fmr = 0; 94 95 regd_buf->dma_addr = dma_addr; 96 regd_buf->direction = direction; 97 } 98 99 /** 100 * iser_start_rdma_unaligned_sg 101 */ 102 static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task, 103 enum iser_data_dir cmd_dir) 104 { 105 int dma_nents; 106 struct ib_device *dev; 107 char *mem = NULL; 108 struct iser_data_buf *data = &iser_task->data[cmd_dir]; 109 unsigned long cmd_data_len = data->data_len; 110 111 if (cmd_data_len > ISER_KMALLOC_THRESHOLD) 112 mem = (void *)__get_free_pages(GFP_NOIO, 113 ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT); 114 else 115 mem = kmalloc(cmd_data_len, GFP_NOIO); 116 117 if (mem == NULL) { 118 iser_err("Failed to allocate mem size %d %d for copying sglist\n", 119 data->size,(int)cmd_data_len); 120 return -ENOMEM; 121 } 122 123 if (cmd_dir == ISER_DIR_OUT) { 124 /* copy the unaligned sg the buffer which is used for RDMA */ 125 struct scatterlist *sgl = (struct scatterlist *)data->buf; 126 struct scatterlist *sg; 127 int i; 128 char *p, *from; 129 130 p = mem; 131 for_each_sg(sgl, sg, data->size, i) { 132 from = kmap_atomic(sg_page(sg), KM_USER0); 133 memcpy(p, 134 from + sg->offset, 135 sg->length); 136 kunmap_atomic(from, KM_USER0); 137 p += sg->length; 138 } 139 } 140 141 sg_init_one(&iser_task->data_copy[cmd_dir].sg_single, mem, cmd_data_len); 142 iser_task->data_copy[cmd_dir].buf = 143 &iser_task->data_copy[cmd_dir].sg_single; 144 iser_task->data_copy[cmd_dir].size = 1; 145 146 iser_task->data_copy[cmd_dir].copy_buf = mem; 147 148 dev = iser_task->iser_conn->ib_conn->device->ib_device; 149 dma_nents = ib_dma_map_sg(dev, 150 &iser_task->data_copy[cmd_dir].sg_single, 151 1, 152 (cmd_dir == ISER_DIR_OUT) ? 153 DMA_TO_DEVICE : DMA_FROM_DEVICE); 154 BUG_ON(dma_nents == 0); 155 156 iser_task->data_copy[cmd_dir].dma_nents = dma_nents; 157 return 0; 158 } 159 160 /** 161 * iser_finalize_rdma_unaligned_sg 162 */ 163 void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task, 164 enum iser_data_dir cmd_dir) 165 { 166 struct ib_device *dev; 167 struct iser_data_buf *mem_copy; 168 unsigned long cmd_data_len; 169 170 dev = iser_task->iser_conn->ib_conn->device->ib_device; 171 mem_copy = &iser_task->data_copy[cmd_dir]; 172 173 ib_dma_unmap_sg(dev, &mem_copy->sg_single, 1, 174 (cmd_dir == ISER_DIR_OUT) ? 175 DMA_TO_DEVICE : DMA_FROM_DEVICE); 176 177 if (cmd_dir == ISER_DIR_IN) { 178 char *mem; 179 struct scatterlist *sgl, *sg; 180 unsigned char *p, *to; 181 unsigned int sg_size; 182 int i; 183 184 /* copy back read RDMA to unaligned sg */ 185 mem = mem_copy->copy_buf; 186 187 sgl = (struct scatterlist *)iser_task->data[ISER_DIR_IN].buf; 188 sg_size = iser_task->data[ISER_DIR_IN].size; 189 190 p = mem; 191 for_each_sg(sgl, sg, sg_size, i) { 192 to = kmap_atomic(sg_page(sg), KM_SOFTIRQ0); 193 memcpy(to + sg->offset, 194 p, 195 sg->length); 196 kunmap_atomic(to, KM_SOFTIRQ0); 197 p += sg->length; 198 } 199 } 200 201 cmd_data_len = iser_task->data[cmd_dir].data_len; 202 203 if (cmd_data_len > ISER_KMALLOC_THRESHOLD) 204 free_pages((unsigned long)mem_copy->copy_buf, 205 ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT); 206 else 207 kfree(mem_copy->copy_buf); 208 209 mem_copy->copy_buf = NULL; 210 } 211 212 #define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0) 213 214 /** 215 * iser_sg_to_page_vec - Translates scatterlist entries to physical addresses 216 * and returns the length of resulting physical address array (may be less than 217 * the original due to possible compaction). 218 * 219 * we build a "page vec" under the assumption that the SG meets the RDMA 220 * alignment requirements. Other then the first and last SG elements, all 221 * the "internal" elements can be compacted into a list whose elements are 222 * dma addresses of physical pages. The code supports also the weird case 223 * where --few fragments of the same page-- are present in the SG as 224 * consecutive elements. Also, it handles one entry SG. 225 */ 226 227 static int iser_sg_to_page_vec(struct iser_data_buf *data, 228 struct iser_page_vec *page_vec, 229 struct ib_device *ibdev) 230 { 231 struct scatterlist *sg, *sgl = (struct scatterlist *)data->buf; 232 u64 start_addr, end_addr, page, chunk_start = 0; 233 unsigned long total_sz = 0; 234 unsigned int dma_len; 235 int i, new_chunk, cur_page, last_ent = data->dma_nents - 1; 236 237 /* compute the offset of first element */ 238 page_vec->offset = (u64) sgl[0].offset & ~MASK_4K; 239 240 new_chunk = 1; 241 cur_page = 0; 242 for_each_sg(sgl, sg, data->dma_nents, i) { 243 start_addr = ib_sg_dma_address(ibdev, sg); 244 if (new_chunk) 245 chunk_start = start_addr; 246 dma_len = ib_sg_dma_len(ibdev, sg); 247 end_addr = start_addr + dma_len; 248 total_sz += dma_len; 249 250 /* collect page fragments until aligned or end of SG list */ 251 if (!IS_4K_ALIGNED(end_addr) && i < last_ent) { 252 new_chunk = 0; 253 continue; 254 } 255 new_chunk = 1; 256 257 /* address of the first page in the contiguous chunk; 258 masking relevant for the very first SG entry, 259 which might be unaligned */ 260 page = chunk_start & MASK_4K; 261 do { 262 page_vec->pages[cur_page++] = page; 263 page += SIZE_4K; 264 } while (page < end_addr); 265 } 266 267 page_vec->data_size = total_sz; 268 iser_dbg("page_vec->data_size:%d cur_page %d\n", page_vec->data_size,cur_page); 269 return cur_page; 270 } 271 272 273 /** 274 * iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned 275 * for RDMA sub-list of a scatter-gather list of memory buffers, and returns 276 * the number of entries which are aligned correctly. Supports the case where 277 * consecutive SG elements are actually fragments of the same physcial page. 278 */ 279 static int iser_data_buf_aligned_len(struct iser_data_buf *data, 280 struct ib_device *ibdev) 281 { 282 struct scatterlist *sgl, *sg, *next_sg = NULL; 283 u64 start_addr, end_addr; 284 int i, ret_len, start_check = 0; 285 286 if (data->dma_nents == 1) 287 return 1; 288 289 sgl = (struct scatterlist *)data->buf; 290 start_addr = ib_sg_dma_address(ibdev, sgl); 291 292 for_each_sg(sgl, sg, data->dma_nents, i) { 293 if (start_check && !IS_4K_ALIGNED(start_addr)) 294 break; 295 296 next_sg = sg_next(sg); 297 if (!next_sg) 298 break; 299 300 end_addr = start_addr + ib_sg_dma_len(ibdev, sg); 301 start_addr = ib_sg_dma_address(ibdev, next_sg); 302 303 if (end_addr == start_addr) { 304 start_check = 0; 305 continue; 306 } else 307 start_check = 1; 308 309 if (!IS_4K_ALIGNED(end_addr)) 310 break; 311 } 312 ret_len = (next_sg) ? i : i+1; 313 iser_dbg("Found %d aligned entries out of %d in sg:0x%p\n", 314 ret_len, data->dma_nents, data); 315 return ret_len; 316 } 317 318 static void iser_data_buf_dump(struct iser_data_buf *data, 319 struct ib_device *ibdev) 320 { 321 struct scatterlist *sgl = (struct scatterlist *)data->buf; 322 struct scatterlist *sg; 323 int i; 324 325 if (iser_debug_level == 0) 326 return; 327 328 for_each_sg(sgl, sg, data->dma_nents, i) 329 iser_warn("sg[%d] dma_addr:0x%lX page:0x%p " 330 "off:0x%x sz:0x%x dma_len:0x%x\n", 331 i, (unsigned long)ib_sg_dma_address(ibdev, sg), 332 sg_page(sg), sg->offset, 333 sg->length, ib_sg_dma_len(ibdev, sg)); 334 } 335 336 static void iser_dump_page_vec(struct iser_page_vec *page_vec) 337 { 338 int i; 339 340 iser_err("page vec length %d data size %d\n", 341 page_vec->length, page_vec->data_size); 342 for (i = 0; i < page_vec->length; i++) 343 iser_err("%d %lx\n",i,(unsigned long)page_vec->pages[i]); 344 } 345 346 static void iser_page_vec_build(struct iser_data_buf *data, 347 struct iser_page_vec *page_vec, 348 struct ib_device *ibdev) 349 { 350 int page_vec_len = 0; 351 352 page_vec->length = 0; 353 page_vec->offset = 0; 354 355 iser_dbg("Translating sg sz: %d\n", data->dma_nents); 356 page_vec_len = iser_sg_to_page_vec(data, page_vec, ibdev); 357 iser_dbg("sg len %d page_vec_len %d\n", data->dma_nents,page_vec_len); 358 359 page_vec->length = page_vec_len; 360 361 if (page_vec_len * SIZE_4K < page_vec->data_size) { 362 iser_err("page_vec too short to hold this SG\n"); 363 iser_data_buf_dump(data, ibdev); 364 iser_dump_page_vec(page_vec); 365 BUG(); 366 } 367 } 368 369 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task, 370 struct iser_data_buf *data, 371 enum iser_data_dir iser_dir, 372 enum dma_data_direction dma_dir) 373 { 374 struct ib_device *dev; 375 376 iser_task->dir[iser_dir] = 1; 377 dev = iser_task->iser_conn->ib_conn->device->ib_device; 378 379 data->dma_nents = ib_dma_map_sg(dev, data->buf, data->size, dma_dir); 380 if (data->dma_nents == 0) { 381 iser_err("dma_map_sg failed!!!\n"); 382 return -EINVAL; 383 } 384 return 0; 385 } 386 387 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task) 388 { 389 struct ib_device *dev; 390 struct iser_data_buf *data; 391 392 dev = iser_task->iser_conn->ib_conn->device->ib_device; 393 394 if (iser_task->dir[ISER_DIR_IN]) { 395 data = &iser_task->data[ISER_DIR_IN]; 396 ib_dma_unmap_sg(dev, data->buf, data->size, DMA_FROM_DEVICE); 397 } 398 399 if (iser_task->dir[ISER_DIR_OUT]) { 400 data = &iser_task->data[ISER_DIR_OUT]; 401 ib_dma_unmap_sg(dev, data->buf, data->size, DMA_TO_DEVICE); 402 } 403 } 404 405 /** 406 * iser_reg_rdma_mem - Registers memory intended for RDMA, 407 * obtaining rkey and va 408 * 409 * returns 0 on success, errno code on failure 410 */ 411 int iser_reg_rdma_mem(struct iscsi_iser_task *iser_task, 412 enum iser_data_dir cmd_dir) 413 { 414 struct iscsi_conn *iscsi_conn = iser_task->iser_conn->iscsi_conn; 415 struct iser_conn *ib_conn = iser_task->iser_conn->ib_conn; 416 struct iser_device *device = ib_conn->device; 417 struct ib_device *ibdev = device->ib_device; 418 struct iser_data_buf *mem = &iser_task->data[cmd_dir]; 419 struct iser_regd_buf *regd_buf; 420 int aligned_len; 421 int err; 422 int i; 423 struct scatterlist *sg; 424 425 regd_buf = &iser_task->rdma_regd[cmd_dir]; 426 427 aligned_len = iser_data_buf_aligned_len(mem, ibdev); 428 if (aligned_len != mem->dma_nents) { 429 iscsi_conn->fmr_unalign_cnt++; 430 iser_warn("rdma alignment violation %d/%d aligned\n", 431 aligned_len, mem->size); 432 iser_data_buf_dump(mem, ibdev); 433 434 /* unmap the command data before accessing it */ 435 iser_dma_unmap_task_data(iser_task); 436 437 /* allocate copy buf, if we are writing, copy the */ 438 /* unaligned scatterlist, dma map the copy */ 439 if (iser_start_rdma_unaligned_sg(iser_task, cmd_dir) != 0) 440 return -ENOMEM; 441 mem = &iser_task->data_copy[cmd_dir]; 442 } 443 444 /* if there a single dma entry, FMR is not needed */ 445 if (mem->dma_nents == 1) { 446 sg = (struct scatterlist *)mem->buf; 447 448 regd_buf->reg.lkey = device->mr->lkey; 449 regd_buf->reg.rkey = device->mr->rkey; 450 regd_buf->reg.len = ib_sg_dma_len(ibdev, &sg[0]); 451 regd_buf->reg.va = ib_sg_dma_address(ibdev, &sg[0]); 452 regd_buf->reg.is_fmr = 0; 453 454 iser_dbg("PHYSICAL Mem.register: lkey: 0x%08X rkey: 0x%08X " 455 "va: 0x%08lX sz: %ld]\n", 456 (unsigned int)regd_buf->reg.lkey, 457 (unsigned int)regd_buf->reg.rkey, 458 (unsigned long)regd_buf->reg.va, 459 (unsigned long)regd_buf->reg.len); 460 } else { /* use FMR for multiple dma entries */ 461 iser_page_vec_build(mem, ib_conn->page_vec, ibdev); 462 err = iser_reg_page_vec(ib_conn, ib_conn->page_vec, ®d_buf->reg); 463 if (err) { 464 iser_data_buf_dump(mem, ibdev); 465 iser_err("mem->dma_nents = %d (dlength = 0x%x)\n", 466 mem->dma_nents, 467 ntoh24(iser_task->desc.iscsi_header.dlength)); 468 iser_err("page_vec: data_size = 0x%x, length = %d, offset = 0x%x\n", 469 ib_conn->page_vec->data_size, ib_conn->page_vec->length, 470 ib_conn->page_vec->offset); 471 for (i=0 ; i<ib_conn->page_vec->length ; i++) 472 iser_err("page_vec[%d] = 0x%llx\n", i, 473 (unsigned long long) ib_conn->page_vec->pages[i]); 474 return err; 475 } 476 } 477 478 /* take a reference on this regd buf such that it will not be released * 479 * (eg in send dto completion) before we get the scsi response */ 480 atomic_inc(®d_buf->ref_count); 481 return 0; 482 } 483