1 /* 2 * Copyright (c) 2014 Mellanox Technologies. 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/types.h> 34 #include <linux/sched.h> 35 #include <linux/pid.h> 36 #include <linux/slab.h> 37 #include <linux/export.h> 38 #include <linux/vmalloc.h> 39 40 #include <rdma/ib_verbs.h> 41 #include <rdma/ib_umem.h> 42 #include <rdma/ib_umem_odp.h> 43 44 static void ib_umem_notifier_start_account(struct ib_umem *item) 45 { 46 mutex_lock(&item->odp_data->umem_mutex); 47 48 /* Only update private counters for this umem if it has them. 49 * Otherwise skip it. All page faults will be delayed for this umem. */ 50 if (item->odp_data->mn_counters_active) { 51 int notifiers_count = item->odp_data->notifiers_count++; 52 53 if (notifiers_count == 0) 54 /* Initialize the completion object for waiting on 55 * notifiers. Since notifier_count is zero, no one 56 * should be waiting right now. */ 57 reinit_completion(&item->odp_data->notifier_completion); 58 } 59 mutex_unlock(&item->odp_data->umem_mutex); 60 } 61 62 static void ib_umem_notifier_end_account(struct ib_umem *item) 63 { 64 mutex_lock(&item->odp_data->umem_mutex); 65 66 /* Only update private counters for this umem if it has them. 67 * Otherwise skip it. All page faults will be delayed for this umem. */ 68 if (item->odp_data->mn_counters_active) { 69 /* 70 * This sequence increase will notify the QP page fault that 71 * the page that is going to be mapped in the spte could have 72 * been freed. 73 */ 74 ++item->odp_data->notifiers_seq; 75 if (--item->odp_data->notifiers_count == 0) 76 complete_all(&item->odp_data->notifier_completion); 77 } 78 mutex_unlock(&item->odp_data->umem_mutex); 79 } 80 81 /* Account for a new mmu notifier in an ib_ucontext. */ 82 static void ib_ucontext_notifier_start_account(struct ib_ucontext *context) 83 { 84 atomic_inc(&context->notifier_count); 85 } 86 87 /* Account for a terminating mmu notifier in an ib_ucontext. 88 * 89 * Must be called with the ib_ucontext->umem_rwsem semaphore unlocked, since 90 * the function takes the semaphore itself. */ 91 static void ib_ucontext_notifier_end_account(struct ib_ucontext *context) 92 { 93 int zero_notifiers = atomic_dec_and_test(&context->notifier_count); 94 95 if (zero_notifiers && 96 !list_empty(&context->no_private_counters)) { 97 /* No currently running mmu notifiers. Now is the chance to 98 * add private accounting to all previously added umems. */ 99 struct ib_umem_odp *odp_data, *next; 100 101 /* Prevent concurrent mmu notifiers from working on the 102 * no_private_counters list. */ 103 down_write(&context->umem_rwsem); 104 105 /* Read the notifier_count again, with the umem_rwsem 106 * semaphore taken for write. */ 107 if (!atomic_read(&context->notifier_count)) { 108 list_for_each_entry_safe(odp_data, next, 109 &context->no_private_counters, 110 no_private_counters) { 111 mutex_lock(&odp_data->umem_mutex); 112 odp_data->mn_counters_active = true; 113 list_del(&odp_data->no_private_counters); 114 complete_all(&odp_data->notifier_completion); 115 mutex_unlock(&odp_data->umem_mutex); 116 } 117 } 118 119 up_write(&context->umem_rwsem); 120 } 121 } 122 123 static int ib_umem_notifier_release_trampoline(struct ib_umem *item, u64 start, 124 u64 end, void *cookie) { 125 /* 126 * Increase the number of notifiers running, to 127 * prevent any further fault handling on this MR. 128 */ 129 ib_umem_notifier_start_account(item); 130 item->odp_data->dying = 1; 131 /* Make sure that the fact the umem is dying is out before we release 132 * all pending page faults. */ 133 smp_wmb(); 134 complete_all(&item->odp_data->notifier_completion); 135 item->context->invalidate_range(item, ib_umem_start(item), 136 ib_umem_end(item)); 137 return 0; 138 } 139 140 static void ib_umem_notifier_release(struct mmu_notifier *mn, 141 struct mm_struct *mm) 142 { 143 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 144 145 if (!context->invalidate_range) 146 return; 147 148 ib_ucontext_notifier_start_account(context); 149 down_read(&context->umem_rwsem); 150 rbt_ib_umem_for_each_in_range(&context->umem_tree, 0, 151 ULLONG_MAX, 152 ib_umem_notifier_release_trampoline, 153 NULL); 154 up_read(&context->umem_rwsem); 155 } 156 157 static int invalidate_page_trampoline(struct ib_umem *item, u64 start, 158 u64 end, void *cookie) 159 { 160 ib_umem_notifier_start_account(item); 161 item->context->invalidate_range(item, start, start + PAGE_SIZE); 162 ib_umem_notifier_end_account(item); 163 return 0; 164 } 165 166 static void ib_umem_notifier_invalidate_page(struct mmu_notifier *mn, 167 struct mm_struct *mm, 168 unsigned long address) 169 { 170 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 171 172 if (!context->invalidate_range) 173 return; 174 175 ib_ucontext_notifier_start_account(context); 176 down_read(&context->umem_rwsem); 177 rbt_ib_umem_for_each_in_range(&context->umem_tree, address, 178 address + PAGE_SIZE, 179 invalidate_page_trampoline, NULL); 180 up_read(&context->umem_rwsem); 181 ib_ucontext_notifier_end_account(context); 182 } 183 184 static int invalidate_range_start_trampoline(struct ib_umem *item, u64 start, 185 u64 end, void *cookie) 186 { 187 ib_umem_notifier_start_account(item); 188 item->context->invalidate_range(item, start, end); 189 return 0; 190 } 191 192 static void ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, 193 struct mm_struct *mm, 194 unsigned long start, 195 unsigned long end) 196 { 197 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 198 199 if (!context->invalidate_range) 200 return; 201 202 ib_ucontext_notifier_start_account(context); 203 down_read(&context->umem_rwsem); 204 rbt_ib_umem_for_each_in_range(&context->umem_tree, start, 205 end, 206 invalidate_range_start_trampoline, NULL); 207 up_read(&context->umem_rwsem); 208 } 209 210 static int invalidate_range_end_trampoline(struct ib_umem *item, u64 start, 211 u64 end, void *cookie) 212 { 213 ib_umem_notifier_end_account(item); 214 return 0; 215 } 216 217 static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, 218 struct mm_struct *mm, 219 unsigned long start, 220 unsigned long end) 221 { 222 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 223 224 if (!context->invalidate_range) 225 return; 226 227 down_read(&context->umem_rwsem); 228 rbt_ib_umem_for_each_in_range(&context->umem_tree, start, 229 end, 230 invalidate_range_end_trampoline, NULL); 231 up_read(&context->umem_rwsem); 232 ib_ucontext_notifier_end_account(context); 233 } 234 235 static const struct mmu_notifier_ops ib_umem_notifiers = { 236 .release = ib_umem_notifier_release, 237 .invalidate_page = ib_umem_notifier_invalidate_page, 238 .invalidate_range_start = ib_umem_notifier_invalidate_range_start, 239 .invalidate_range_end = ib_umem_notifier_invalidate_range_end, 240 }; 241 242 struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context, 243 unsigned long addr, 244 size_t size) 245 { 246 struct ib_umem *umem; 247 struct ib_umem_odp *odp_data; 248 int pages = size >> PAGE_SHIFT; 249 int ret; 250 251 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 252 if (!umem) 253 return ERR_PTR(-ENOMEM); 254 255 umem->context = context; 256 umem->length = size; 257 umem->address = addr; 258 umem->page_size = PAGE_SIZE; 259 umem->writable = 1; 260 261 odp_data = kzalloc(sizeof(*odp_data), GFP_KERNEL); 262 if (!odp_data) { 263 ret = -ENOMEM; 264 goto out_umem; 265 } 266 odp_data->umem = umem; 267 268 mutex_init(&odp_data->umem_mutex); 269 init_completion(&odp_data->notifier_completion); 270 271 odp_data->page_list = vzalloc(pages * sizeof(*odp_data->page_list)); 272 if (!odp_data->page_list) { 273 ret = -ENOMEM; 274 goto out_odp_data; 275 } 276 277 odp_data->dma_list = vzalloc(pages * sizeof(*odp_data->dma_list)); 278 if (!odp_data->dma_list) { 279 ret = -ENOMEM; 280 goto out_page_list; 281 } 282 283 down_write(&context->umem_rwsem); 284 context->odp_mrs_count++; 285 rbt_ib_umem_insert(&odp_data->interval_tree, &context->umem_tree); 286 if (likely(!atomic_read(&context->notifier_count))) 287 odp_data->mn_counters_active = true; 288 else 289 list_add(&odp_data->no_private_counters, 290 &context->no_private_counters); 291 up_write(&context->umem_rwsem); 292 293 umem->odp_data = odp_data; 294 295 return umem; 296 297 out_page_list: 298 vfree(odp_data->page_list); 299 out_odp_data: 300 kfree(odp_data); 301 out_umem: 302 kfree(umem); 303 return ERR_PTR(ret); 304 } 305 EXPORT_SYMBOL(ib_alloc_odp_umem); 306 307 int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem) 308 { 309 int ret_val; 310 struct pid *our_pid; 311 struct mm_struct *mm = get_task_mm(current); 312 313 if (!mm) 314 return -EINVAL; 315 316 /* Prevent creating ODP MRs in child processes */ 317 rcu_read_lock(); 318 our_pid = get_task_pid(current->group_leader, PIDTYPE_PID); 319 rcu_read_unlock(); 320 put_pid(our_pid); 321 if (context->tgid != our_pid) { 322 ret_val = -EINVAL; 323 goto out_mm; 324 } 325 326 umem->hugetlb = 0; 327 umem->odp_data = kzalloc(sizeof(*umem->odp_data), GFP_KERNEL); 328 if (!umem->odp_data) { 329 ret_val = -ENOMEM; 330 goto out_mm; 331 } 332 umem->odp_data->umem = umem; 333 334 mutex_init(&umem->odp_data->umem_mutex); 335 336 init_completion(&umem->odp_data->notifier_completion); 337 338 if (ib_umem_num_pages(umem)) { 339 umem->odp_data->page_list = vzalloc(ib_umem_num_pages(umem) * 340 sizeof(*umem->odp_data->page_list)); 341 if (!umem->odp_data->page_list) { 342 ret_val = -ENOMEM; 343 goto out_odp_data; 344 } 345 346 umem->odp_data->dma_list = vzalloc(ib_umem_num_pages(umem) * 347 sizeof(*umem->odp_data->dma_list)); 348 if (!umem->odp_data->dma_list) { 349 ret_val = -ENOMEM; 350 goto out_page_list; 351 } 352 } 353 354 /* 355 * When using MMU notifiers, we will get a 356 * notification before the "current" task (and MM) is 357 * destroyed. We use the umem_rwsem semaphore to synchronize. 358 */ 359 down_write(&context->umem_rwsem); 360 context->odp_mrs_count++; 361 if (likely(ib_umem_start(umem) != ib_umem_end(umem))) 362 rbt_ib_umem_insert(&umem->odp_data->interval_tree, 363 &context->umem_tree); 364 if (likely(!atomic_read(&context->notifier_count)) || 365 context->odp_mrs_count == 1) 366 umem->odp_data->mn_counters_active = true; 367 else 368 list_add(&umem->odp_data->no_private_counters, 369 &context->no_private_counters); 370 downgrade_write(&context->umem_rwsem); 371 372 if (context->odp_mrs_count == 1) { 373 /* 374 * Note that at this point, no MMU notifier is running 375 * for this context! 376 */ 377 atomic_set(&context->notifier_count, 0); 378 INIT_HLIST_NODE(&context->mn.hlist); 379 context->mn.ops = &ib_umem_notifiers; 380 /* 381 * Lock-dep detects a false positive for mmap_sem vs. 382 * umem_rwsem, due to not grasping downgrade_write correctly. 383 */ 384 lockdep_off(); 385 ret_val = mmu_notifier_register(&context->mn, mm); 386 lockdep_on(); 387 if (ret_val) { 388 pr_err("Failed to register mmu_notifier %d\n", ret_val); 389 ret_val = -EBUSY; 390 goto out_mutex; 391 } 392 } 393 394 up_read(&context->umem_rwsem); 395 396 /* 397 * Note that doing an mmput can cause a notifier for the relevant mm. 398 * If the notifier is called while we hold the umem_rwsem, this will 399 * cause a deadlock. Therefore, we release the reference only after we 400 * released the semaphore. 401 */ 402 mmput(mm); 403 return 0; 404 405 out_mutex: 406 up_read(&context->umem_rwsem); 407 vfree(umem->odp_data->dma_list); 408 out_page_list: 409 vfree(umem->odp_data->page_list); 410 out_odp_data: 411 kfree(umem->odp_data); 412 out_mm: 413 mmput(mm); 414 return ret_val; 415 } 416 417 void ib_umem_odp_release(struct ib_umem *umem) 418 { 419 struct ib_ucontext *context = umem->context; 420 421 /* 422 * Ensure that no more pages are mapped in the umem. 423 * 424 * It is the driver's responsibility to ensure, before calling us, 425 * that the hardware will not attempt to access the MR any more. 426 */ 427 ib_umem_odp_unmap_dma_pages(umem, ib_umem_start(umem), 428 ib_umem_end(umem)); 429 430 down_write(&context->umem_rwsem); 431 if (likely(ib_umem_start(umem) != ib_umem_end(umem))) 432 rbt_ib_umem_remove(&umem->odp_data->interval_tree, 433 &context->umem_tree); 434 context->odp_mrs_count--; 435 if (!umem->odp_data->mn_counters_active) { 436 list_del(&umem->odp_data->no_private_counters); 437 complete_all(&umem->odp_data->notifier_completion); 438 } 439 440 /* 441 * Downgrade the lock to a read lock. This ensures that the notifiers 442 * (who lock the mutex for reading) will be able to finish, and we 443 * will be able to enventually obtain the mmu notifiers SRCU. Note 444 * that since we are doing it atomically, no other user could register 445 * and unregister while we do the check. 446 */ 447 downgrade_write(&context->umem_rwsem); 448 if (!context->odp_mrs_count) { 449 struct task_struct *owning_process = NULL; 450 struct mm_struct *owning_mm = NULL; 451 452 owning_process = get_pid_task(context->tgid, 453 PIDTYPE_PID); 454 if (owning_process == NULL) 455 /* 456 * The process is already dead, notifier were removed 457 * already. 458 */ 459 goto out; 460 461 owning_mm = get_task_mm(owning_process); 462 if (owning_mm == NULL) 463 /* 464 * The process' mm is already dead, notifier were 465 * removed already. 466 */ 467 goto out_put_task; 468 mmu_notifier_unregister(&context->mn, owning_mm); 469 470 mmput(owning_mm); 471 472 out_put_task: 473 put_task_struct(owning_process); 474 } 475 out: 476 up_read(&context->umem_rwsem); 477 478 vfree(umem->odp_data->dma_list); 479 vfree(umem->odp_data->page_list); 480 kfree(umem->odp_data); 481 kfree(umem); 482 } 483 484 /* 485 * Map for DMA and insert a single page into the on-demand paging page tables. 486 * 487 * @umem: the umem to insert the page to. 488 * @page_index: index in the umem to add the page to. 489 * @page: the page struct to map and add. 490 * @access_mask: access permissions needed for this page. 491 * @current_seq: sequence number for synchronization with invalidations. 492 * the sequence number is taken from 493 * umem->odp_data->notifiers_seq. 494 * 495 * The function returns -EFAULT if the DMA mapping operation fails. It returns 496 * -EAGAIN if a concurrent invalidation prevents us from updating the page. 497 * 498 * The page is released via put_page even if the operation failed. For 499 * on-demand pinning, the page is released whenever it isn't stored in the 500 * umem. 501 */ 502 static int ib_umem_odp_map_dma_single_page( 503 struct ib_umem *umem, 504 int page_index, 505 u64 base_virt_addr, 506 struct page *page, 507 u64 access_mask, 508 unsigned long current_seq) 509 { 510 struct ib_device *dev = umem->context->device; 511 dma_addr_t dma_addr; 512 int stored_page = 0; 513 int remove_existing_mapping = 0; 514 int ret = 0; 515 516 /* 517 * Note: we avoid writing if seq is different from the initial seq, to 518 * handle case of a racing notifier. This check also allows us to bail 519 * early if we have a notifier running in parallel with us. 520 */ 521 if (ib_umem_mmu_notifier_retry(umem, current_seq)) { 522 ret = -EAGAIN; 523 goto out; 524 } 525 if (!(umem->odp_data->dma_list[page_index])) { 526 dma_addr = ib_dma_map_page(dev, 527 page, 528 0, PAGE_SIZE, 529 DMA_BIDIRECTIONAL); 530 if (ib_dma_mapping_error(dev, dma_addr)) { 531 ret = -EFAULT; 532 goto out; 533 } 534 umem->odp_data->dma_list[page_index] = dma_addr | access_mask; 535 umem->odp_data->page_list[page_index] = page; 536 umem->npages++; 537 stored_page = 1; 538 } else if (umem->odp_data->page_list[page_index] == page) { 539 umem->odp_data->dma_list[page_index] |= access_mask; 540 } else { 541 pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n", 542 umem->odp_data->page_list[page_index], page); 543 /* Better remove the mapping now, to prevent any further 544 * damage. */ 545 remove_existing_mapping = 1; 546 } 547 548 out: 549 /* On Demand Paging - avoid pinning the page */ 550 if (umem->context->invalidate_range || !stored_page) 551 put_page(page); 552 553 if (remove_existing_mapping && umem->context->invalidate_range) { 554 invalidate_page_trampoline( 555 umem, 556 base_virt_addr + (page_index * PAGE_SIZE), 557 base_virt_addr + ((page_index+1)*PAGE_SIZE), 558 NULL); 559 ret = -EAGAIN; 560 } 561 562 return ret; 563 } 564 565 /** 566 * ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR. 567 * 568 * Pins the range of pages passed in the argument, and maps them to 569 * DMA addresses. The DMA addresses of the mapped pages is updated in 570 * umem->odp_data->dma_list. 571 * 572 * Returns the number of pages mapped in success, negative error code 573 * for failure. 574 * An -EAGAIN error code is returned when a concurrent mmu notifier prevents 575 * the function from completing its task. 576 * An -ENOENT error code indicates that userspace process is being terminated 577 * and mm was already destroyed. 578 * @umem: the umem to map and pin 579 * @user_virt: the address from which we need to map. 580 * @bcnt: the minimal number of bytes to pin and map. The mapping might be 581 * bigger due to alignment, and may also be smaller in case of an error 582 * pinning or mapping a page. The actual pages mapped is returned in 583 * the return value. 584 * @access_mask: bit mask of the requested access permissions for the given 585 * range. 586 * @current_seq: the MMU notifiers sequance value for synchronization with 587 * invalidations. the sequance number is read from 588 * umem->odp_data->notifiers_seq before calling this function 589 */ 590 int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt, 591 u64 access_mask, unsigned long current_seq) 592 { 593 struct task_struct *owning_process = NULL; 594 struct mm_struct *owning_mm = NULL; 595 struct page **local_page_list = NULL; 596 u64 off; 597 int j, k, ret = 0, start_idx, npages = 0; 598 u64 base_virt_addr; 599 unsigned int flags = 0; 600 601 if (access_mask == 0) 602 return -EINVAL; 603 604 if (user_virt < ib_umem_start(umem) || 605 user_virt + bcnt > ib_umem_end(umem)) 606 return -EFAULT; 607 608 local_page_list = (struct page **)__get_free_page(GFP_KERNEL); 609 if (!local_page_list) 610 return -ENOMEM; 611 612 off = user_virt & (~PAGE_MASK); 613 user_virt = user_virt & PAGE_MASK; 614 base_virt_addr = user_virt; 615 bcnt += off; /* Charge for the first page offset as well. */ 616 617 owning_process = get_pid_task(umem->context->tgid, PIDTYPE_PID); 618 if (owning_process == NULL) { 619 ret = -EINVAL; 620 goto out_no_task; 621 } 622 623 owning_mm = get_task_mm(owning_process); 624 if (owning_mm == NULL) { 625 ret = -ENOENT; 626 goto out_put_task; 627 } 628 629 if (access_mask & ODP_WRITE_ALLOWED_BIT) 630 flags |= FOLL_WRITE; 631 632 start_idx = (user_virt - ib_umem_start(umem)) >> PAGE_SHIFT; 633 k = start_idx; 634 635 while (bcnt > 0) { 636 const size_t gup_num_pages = 637 min_t(size_t, ALIGN(bcnt, PAGE_SIZE) / PAGE_SIZE, 638 PAGE_SIZE / sizeof(struct page *)); 639 640 down_read(&owning_mm->mmap_sem); 641 /* 642 * Note: this might result in redundent page getting. We can 643 * avoid this by checking dma_list to be 0 before calling 644 * get_user_pages. However, this make the code much more 645 * complex (and doesn't gain us much performance in most use 646 * cases). 647 */ 648 npages = get_user_pages_remote(owning_process, owning_mm, 649 user_virt, gup_num_pages, 650 flags, local_page_list, NULL, NULL); 651 up_read(&owning_mm->mmap_sem); 652 653 if (npages < 0) 654 break; 655 656 bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt); 657 user_virt += npages << PAGE_SHIFT; 658 mutex_lock(&umem->odp_data->umem_mutex); 659 for (j = 0; j < npages; ++j) { 660 ret = ib_umem_odp_map_dma_single_page( 661 umem, k, base_virt_addr, local_page_list[j], 662 access_mask, current_seq); 663 if (ret < 0) 664 break; 665 k++; 666 } 667 mutex_unlock(&umem->odp_data->umem_mutex); 668 669 if (ret < 0) { 670 /* Release left over pages when handling errors. */ 671 for (++j; j < npages; ++j) 672 put_page(local_page_list[j]); 673 break; 674 } 675 } 676 677 if (ret >= 0) { 678 if (npages < 0 && k == start_idx) 679 ret = npages; 680 else 681 ret = k - start_idx; 682 } 683 684 mmput(owning_mm); 685 out_put_task: 686 put_task_struct(owning_process); 687 out_no_task: 688 free_page((unsigned long)local_page_list); 689 return ret; 690 } 691 EXPORT_SYMBOL(ib_umem_odp_map_dma_pages); 692 693 void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt, 694 u64 bound) 695 { 696 int idx; 697 u64 addr; 698 struct ib_device *dev = umem->context->device; 699 700 virt = max_t(u64, virt, ib_umem_start(umem)); 701 bound = min_t(u64, bound, ib_umem_end(umem)); 702 /* Note that during the run of this function, the 703 * notifiers_count of the MR is > 0, preventing any racing 704 * faults from completion. We might be racing with other 705 * invalidations, so we must make sure we free each page only 706 * once. */ 707 mutex_lock(&umem->odp_data->umem_mutex); 708 for (addr = virt; addr < bound; addr += (u64)umem->page_size) { 709 idx = (addr - ib_umem_start(umem)) / PAGE_SIZE; 710 if (umem->odp_data->page_list[idx]) { 711 struct page *page = umem->odp_data->page_list[idx]; 712 dma_addr_t dma = umem->odp_data->dma_list[idx]; 713 dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK; 714 715 WARN_ON(!dma_addr); 716 717 ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE, 718 DMA_BIDIRECTIONAL); 719 if (dma & ODP_WRITE_ALLOWED_BIT) { 720 struct page *head_page = compound_head(page); 721 /* 722 * set_page_dirty prefers being called with 723 * the page lock. However, MMU notifiers are 724 * called sometimes with and sometimes without 725 * the lock. We rely on the umem_mutex instead 726 * to prevent other mmu notifiers from 727 * continuing and allowing the page mapping to 728 * be removed. 729 */ 730 set_page_dirty(head_page); 731 } 732 /* on demand pinning support */ 733 if (!umem->context->invalidate_range) 734 put_page(page); 735 umem->odp_data->page_list[idx] = NULL; 736 umem->odp_data->dma_list[idx] = 0; 737 umem->npages--; 738 } 739 } 740 mutex_unlock(&umem->odp_data->umem_mutex); 741 } 742 EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages); 743