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/sched/mm.h> 36 #include <linux/sched/task.h> 37 #include <linux/pid.h> 38 #include <linux/slab.h> 39 #include <linux/export.h> 40 #include <linux/vmalloc.h> 41 #include <linux/hugetlb.h> 42 43 #include <rdma/ib_verbs.h> 44 #include <rdma/ib_umem.h> 45 #include <rdma/ib_umem_odp.h> 46 47 static void ib_umem_notifier_start_account(struct ib_umem *item) 48 { 49 mutex_lock(&item->odp_data->umem_mutex); 50 51 /* Only update private counters for this umem if it has them. 52 * Otherwise skip it. All page faults will be delayed for this umem. */ 53 if (item->odp_data->mn_counters_active) { 54 int notifiers_count = item->odp_data->notifiers_count++; 55 56 if (notifiers_count == 0) 57 /* Initialize the completion object for waiting on 58 * notifiers. Since notifier_count is zero, no one 59 * should be waiting right now. */ 60 reinit_completion(&item->odp_data->notifier_completion); 61 } 62 mutex_unlock(&item->odp_data->umem_mutex); 63 } 64 65 static void ib_umem_notifier_end_account(struct ib_umem *item) 66 { 67 mutex_lock(&item->odp_data->umem_mutex); 68 69 /* Only update private counters for this umem if it has them. 70 * Otherwise skip it. All page faults will be delayed for this umem. */ 71 if (item->odp_data->mn_counters_active) { 72 /* 73 * This sequence increase will notify the QP page fault that 74 * the page that is going to be mapped in the spte could have 75 * been freed. 76 */ 77 ++item->odp_data->notifiers_seq; 78 if (--item->odp_data->notifiers_count == 0) 79 complete_all(&item->odp_data->notifier_completion); 80 } 81 mutex_unlock(&item->odp_data->umem_mutex); 82 } 83 84 /* Account for a new mmu notifier in an ib_ucontext. */ 85 static void ib_ucontext_notifier_start_account(struct ib_ucontext *context) 86 { 87 atomic_inc(&context->notifier_count); 88 } 89 90 /* Account for a terminating mmu notifier in an ib_ucontext. 91 * 92 * Must be called with the ib_ucontext->umem_rwsem semaphore unlocked, since 93 * the function takes the semaphore itself. */ 94 static void ib_ucontext_notifier_end_account(struct ib_ucontext *context) 95 { 96 int zero_notifiers = atomic_dec_and_test(&context->notifier_count); 97 98 if (zero_notifiers && 99 !list_empty(&context->no_private_counters)) { 100 /* No currently running mmu notifiers. Now is the chance to 101 * add private accounting to all previously added umems. */ 102 struct ib_umem_odp *odp_data, *next; 103 104 /* Prevent concurrent mmu notifiers from working on the 105 * no_private_counters list. */ 106 down_write(&context->umem_rwsem); 107 108 /* Read the notifier_count again, with the umem_rwsem 109 * semaphore taken for write. */ 110 if (!atomic_read(&context->notifier_count)) { 111 list_for_each_entry_safe(odp_data, next, 112 &context->no_private_counters, 113 no_private_counters) { 114 mutex_lock(&odp_data->umem_mutex); 115 odp_data->mn_counters_active = true; 116 list_del(&odp_data->no_private_counters); 117 complete_all(&odp_data->notifier_completion); 118 mutex_unlock(&odp_data->umem_mutex); 119 } 120 } 121 122 up_write(&context->umem_rwsem); 123 } 124 } 125 126 static int ib_umem_notifier_release_trampoline(struct ib_umem *item, u64 start, 127 u64 end, void *cookie) { 128 /* 129 * Increase the number of notifiers running, to 130 * prevent any further fault handling on this MR. 131 */ 132 ib_umem_notifier_start_account(item); 133 item->odp_data->dying = 1; 134 /* Make sure that the fact the umem is dying is out before we release 135 * all pending page faults. */ 136 smp_wmb(); 137 complete_all(&item->odp_data->notifier_completion); 138 item->context->invalidate_range(item, ib_umem_start(item), 139 ib_umem_end(item)); 140 return 0; 141 } 142 143 static void ib_umem_notifier_release(struct mmu_notifier *mn, 144 struct mm_struct *mm) 145 { 146 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 147 148 if (!context->invalidate_range) 149 return; 150 151 ib_ucontext_notifier_start_account(context); 152 down_read(&context->umem_rwsem); 153 rbt_ib_umem_for_each_in_range(&context->umem_tree, 0, 154 ULLONG_MAX, 155 ib_umem_notifier_release_trampoline, 156 NULL); 157 up_read(&context->umem_rwsem); 158 } 159 160 static int invalidate_page_trampoline(struct ib_umem *item, u64 start, 161 u64 end, void *cookie) 162 { 163 ib_umem_notifier_start_account(item); 164 item->context->invalidate_range(item, start, start + PAGE_SIZE); 165 ib_umem_notifier_end_account(item); 166 return 0; 167 } 168 169 static int invalidate_range_start_trampoline(struct ib_umem *item, u64 start, 170 u64 end, void *cookie) 171 { 172 ib_umem_notifier_start_account(item); 173 item->context->invalidate_range(item, start, end); 174 return 0; 175 } 176 177 static void ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, 178 struct mm_struct *mm, 179 unsigned long start, 180 unsigned long end) 181 { 182 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 183 184 if (!context->invalidate_range) 185 return; 186 187 ib_ucontext_notifier_start_account(context); 188 down_read(&context->umem_rwsem); 189 rbt_ib_umem_for_each_in_range(&context->umem_tree, start, 190 end, 191 invalidate_range_start_trampoline, NULL); 192 up_read(&context->umem_rwsem); 193 } 194 195 static int invalidate_range_end_trampoline(struct ib_umem *item, u64 start, 196 u64 end, void *cookie) 197 { 198 ib_umem_notifier_end_account(item); 199 return 0; 200 } 201 202 static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, 203 struct mm_struct *mm, 204 unsigned long start, 205 unsigned long end) 206 { 207 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 208 209 if (!context->invalidate_range) 210 return; 211 212 down_read(&context->umem_rwsem); 213 rbt_ib_umem_for_each_in_range(&context->umem_tree, start, 214 end, 215 invalidate_range_end_trampoline, NULL); 216 up_read(&context->umem_rwsem); 217 ib_ucontext_notifier_end_account(context); 218 } 219 220 static const struct mmu_notifier_ops ib_umem_notifiers = { 221 .release = ib_umem_notifier_release, 222 .invalidate_range_start = ib_umem_notifier_invalidate_range_start, 223 .invalidate_range_end = ib_umem_notifier_invalidate_range_end, 224 }; 225 226 struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context, 227 unsigned long addr, 228 size_t size) 229 { 230 struct ib_umem *umem; 231 struct ib_umem_odp *odp_data; 232 int pages = size >> PAGE_SHIFT; 233 int ret; 234 235 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 236 if (!umem) 237 return ERR_PTR(-ENOMEM); 238 239 umem->context = context; 240 umem->length = size; 241 umem->address = addr; 242 umem->page_shift = PAGE_SHIFT; 243 umem->writable = 1; 244 245 odp_data = kzalloc(sizeof(*odp_data), GFP_KERNEL); 246 if (!odp_data) { 247 ret = -ENOMEM; 248 goto out_umem; 249 } 250 odp_data->umem = umem; 251 252 mutex_init(&odp_data->umem_mutex); 253 init_completion(&odp_data->notifier_completion); 254 255 odp_data->page_list = vzalloc(pages * sizeof(*odp_data->page_list)); 256 if (!odp_data->page_list) { 257 ret = -ENOMEM; 258 goto out_odp_data; 259 } 260 261 odp_data->dma_list = vzalloc(pages * sizeof(*odp_data->dma_list)); 262 if (!odp_data->dma_list) { 263 ret = -ENOMEM; 264 goto out_page_list; 265 } 266 267 down_write(&context->umem_rwsem); 268 context->odp_mrs_count++; 269 rbt_ib_umem_insert(&odp_data->interval_tree, &context->umem_tree); 270 if (likely(!atomic_read(&context->notifier_count))) 271 odp_data->mn_counters_active = true; 272 else 273 list_add(&odp_data->no_private_counters, 274 &context->no_private_counters); 275 up_write(&context->umem_rwsem); 276 277 umem->odp_data = odp_data; 278 279 return umem; 280 281 out_page_list: 282 vfree(odp_data->page_list); 283 out_odp_data: 284 kfree(odp_data); 285 out_umem: 286 kfree(umem); 287 return ERR_PTR(ret); 288 } 289 EXPORT_SYMBOL(ib_alloc_odp_umem); 290 291 int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem, 292 int access) 293 { 294 int ret_val; 295 struct pid *our_pid; 296 struct mm_struct *mm = get_task_mm(current); 297 298 if (!mm) 299 return -EINVAL; 300 301 if (access & IB_ACCESS_HUGETLB) { 302 struct vm_area_struct *vma; 303 struct hstate *h; 304 305 down_read(&mm->mmap_sem); 306 vma = find_vma(mm, ib_umem_start(umem)); 307 if (!vma || !is_vm_hugetlb_page(vma)) { 308 up_read(&mm->mmap_sem); 309 return -EINVAL; 310 } 311 h = hstate_vma(vma); 312 umem->page_shift = huge_page_shift(h); 313 up_read(&mm->mmap_sem); 314 umem->hugetlb = 1; 315 } else { 316 umem->hugetlb = 0; 317 } 318 319 /* Prevent creating ODP MRs in child processes */ 320 rcu_read_lock(); 321 our_pid = get_task_pid(current->group_leader, PIDTYPE_PID); 322 rcu_read_unlock(); 323 put_pid(our_pid); 324 if (context->tgid != our_pid) { 325 ret_val = -EINVAL; 326 goto out_mm; 327 } 328 329 umem->odp_data = kzalloc(sizeof(*umem->odp_data), GFP_KERNEL); 330 if (!umem->odp_data) { 331 ret_val = -ENOMEM; 332 goto out_mm; 333 } 334 umem->odp_data->umem = umem; 335 336 mutex_init(&umem->odp_data->umem_mutex); 337 338 init_completion(&umem->odp_data->notifier_completion); 339 340 if (ib_umem_num_pages(umem)) { 341 umem->odp_data->page_list = vzalloc(ib_umem_num_pages(umem) * 342 sizeof(*umem->odp_data->page_list)); 343 if (!umem->odp_data->page_list) { 344 ret_val = -ENOMEM; 345 goto out_odp_data; 346 } 347 348 umem->odp_data->dma_list = vzalloc(ib_umem_num_pages(umem) * 349 sizeof(*umem->odp_data->dma_list)); 350 if (!umem->odp_data->dma_list) { 351 ret_val = -ENOMEM; 352 goto out_page_list; 353 } 354 } 355 356 /* 357 * When using MMU notifiers, we will get a 358 * notification before the "current" task (and MM) is 359 * destroyed. We use the umem_rwsem semaphore to synchronize. 360 */ 361 down_write(&context->umem_rwsem); 362 context->odp_mrs_count++; 363 if (likely(ib_umem_start(umem) != ib_umem_end(umem))) 364 rbt_ib_umem_insert(&umem->odp_data->interval_tree, 365 &context->umem_tree); 366 if (likely(!atomic_read(&context->notifier_count)) || 367 context->odp_mrs_count == 1) 368 umem->odp_data->mn_counters_active = true; 369 else 370 list_add(&umem->odp_data->no_private_counters, 371 &context->no_private_counters); 372 downgrade_write(&context->umem_rwsem); 373 374 if (context->odp_mrs_count == 1) { 375 /* 376 * Note that at this point, no MMU notifier is running 377 * for this context! 378 */ 379 atomic_set(&context->notifier_count, 0); 380 INIT_HLIST_NODE(&context->mn.hlist); 381 context->mn.ops = &ib_umem_notifiers; 382 /* 383 * Lock-dep detects a false positive for mmap_sem vs. 384 * umem_rwsem, due to not grasping downgrade_write correctly. 385 */ 386 lockdep_off(); 387 ret_val = mmu_notifier_register(&context->mn, mm); 388 lockdep_on(); 389 if (ret_val) { 390 pr_err("Failed to register mmu_notifier %d\n", ret_val); 391 ret_val = -EBUSY; 392 goto out_mutex; 393 } 394 } 395 396 up_read(&context->umem_rwsem); 397 398 /* 399 * Note that doing an mmput can cause a notifier for the relevant mm. 400 * If the notifier is called while we hold the umem_rwsem, this will 401 * cause a deadlock. Therefore, we release the reference only after we 402 * released the semaphore. 403 */ 404 mmput(mm); 405 return 0; 406 407 out_mutex: 408 up_read(&context->umem_rwsem); 409 vfree(umem->odp_data->dma_list); 410 out_page_list: 411 vfree(umem->odp_data->page_list); 412 out_odp_data: 413 kfree(umem->odp_data); 414 out_mm: 415 mmput(mm); 416 return ret_val; 417 } 418 419 void ib_umem_odp_release(struct ib_umem *umem) 420 { 421 struct ib_ucontext *context = umem->context; 422 423 /* 424 * Ensure that no more pages are mapped in the umem. 425 * 426 * It is the driver's responsibility to ensure, before calling us, 427 * that the hardware will not attempt to access the MR any more. 428 */ 429 ib_umem_odp_unmap_dma_pages(umem, ib_umem_start(umem), 430 ib_umem_end(umem)); 431 432 down_write(&context->umem_rwsem); 433 if (likely(ib_umem_start(umem) != ib_umem_end(umem))) 434 rbt_ib_umem_remove(&umem->odp_data->interval_tree, 435 &context->umem_tree); 436 context->odp_mrs_count--; 437 if (!umem->odp_data->mn_counters_active) { 438 list_del(&umem->odp_data->no_private_counters); 439 complete_all(&umem->odp_data->notifier_completion); 440 } 441 442 /* 443 * Downgrade the lock to a read lock. This ensures that the notifiers 444 * (who lock the mutex for reading) will be able to finish, and we 445 * will be able to enventually obtain the mmu notifiers SRCU. Note 446 * that since we are doing it atomically, no other user could register 447 * and unregister while we do the check. 448 */ 449 downgrade_write(&context->umem_rwsem); 450 if (!context->odp_mrs_count) { 451 struct task_struct *owning_process = NULL; 452 struct mm_struct *owning_mm = NULL; 453 454 owning_process = get_pid_task(context->tgid, 455 PIDTYPE_PID); 456 if (owning_process == NULL) 457 /* 458 * The process is already dead, notifier were removed 459 * already. 460 */ 461 goto out; 462 463 owning_mm = get_task_mm(owning_process); 464 if (owning_mm == NULL) 465 /* 466 * The process' mm is already dead, notifier were 467 * removed already. 468 */ 469 goto out_put_task; 470 mmu_notifier_unregister(&context->mn, owning_mm); 471 472 mmput(owning_mm); 473 474 out_put_task: 475 put_task_struct(owning_process); 476 } 477 out: 478 up_read(&context->umem_rwsem); 479 480 vfree(umem->odp_data->dma_list); 481 vfree(umem->odp_data->page_list); 482 kfree(umem->odp_data); 483 kfree(umem); 484 } 485 486 /* 487 * Map for DMA and insert a single page into the on-demand paging page tables. 488 * 489 * @umem: the umem to insert the page to. 490 * @page_index: index in the umem to add the page to. 491 * @page: the page struct to map and add. 492 * @access_mask: access permissions needed for this page. 493 * @current_seq: sequence number for synchronization with invalidations. 494 * the sequence number is taken from 495 * umem->odp_data->notifiers_seq. 496 * 497 * The function returns -EFAULT if the DMA mapping operation fails. It returns 498 * -EAGAIN if a concurrent invalidation prevents us from updating the page. 499 * 500 * The page is released via put_page even if the operation failed. For 501 * on-demand pinning, the page is released whenever it isn't stored in the 502 * umem. 503 */ 504 static int ib_umem_odp_map_dma_single_page( 505 struct ib_umem *umem, 506 int page_index, 507 struct page *page, 508 u64 access_mask, 509 unsigned long current_seq) 510 { 511 struct ib_device *dev = umem->context->device; 512 dma_addr_t dma_addr; 513 int stored_page = 0; 514 int remove_existing_mapping = 0; 515 int ret = 0; 516 517 /* 518 * Note: we avoid writing if seq is different from the initial seq, to 519 * handle case of a racing notifier. This check also allows us to bail 520 * early if we have a notifier running in parallel with us. 521 */ 522 if (ib_umem_mmu_notifier_retry(umem, current_seq)) { 523 ret = -EAGAIN; 524 goto out; 525 } 526 if (!(umem->odp_data->dma_list[page_index])) { 527 dma_addr = ib_dma_map_page(dev, 528 page, 529 0, BIT(umem->page_shift), 530 DMA_BIDIRECTIONAL); 531 if (ib_dma_mapping_error(dev, dma_addr)) { 532 ret = -EFAULT; 533 goto out; 534 } 535 umem->odp_data->dma_list[page_index] = dma_addr | access_mask; 536 umem->odp_data->page_list[page_index] = page; 537 umem->npages++; 538 stored_page = 1; 539 } else if (umem->odp_data->page_list[page_index] == page) { 540 umem->odp_data->dma_list[page_index] |= access_mask; 541 } else { 542 pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n", 543 umem->odp_data->page_list[page_index], page); 544 /* Better remove the mapping now, to prevent any further 545 * damage. */ 546 remove_existing_mapping = 1; 547 } 548 549 out: 550 /* On Demand Paging - avoid pinning the page */ 551 if (umem->context->invalidate_range || !stored_page) 552 put_page(page); 553 554 if (remove_existing_mapping && umem->context->invalidate_range) { 555 invalidate_page_trampoline( 556 umem, 557 ib_umem_start(umem) + (page_index >> umem->page_shift), 558 ib_umem_start(umem) + ((page_index + 1) >> 559 umem->page_shift), 560 NULL); 561 ret = -EAGAIN; 562 } 563 564 return ret; 565 } 566 567 /** 568 * ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR. 569 * 570 * Pins the range of pages passed in the argument, and maps them to 571 * DMA addresses. The DMA addresses of the mapped pages is updated in 572 * umem->odp_data->dma_list. 573 * 574 * Returns the number of pages mapped in success, negative error code 575 * for failure. 576 * An -EAGAIN error code is returned when a concurrent mmu notifier prevents 577 * the function from completing its task. 578 * An -ENOENT error code indicates that userspace process is being terminated 579 * and mm was already destroyed. 580 * @umem: the umem to map and pin 581 * @user_virt: the address from which we need to map. 582 * @bcnt: the minimal number of bytes to pin and map. The mapping might be 583 * bigger due to alignment, and may also be smaller in case of an error 584 * pinning or mapping a page. The actual pages mapped is returned in 585 * the return value. 586 * @access_mask: bit mask of the requested access permissions for the given 587 * range. 588 * @current_seq: the MMU notifiers sequance value for synchronization with 589 * invalidations. the sequance number is read from 590 * umem->odp_data->notifiers_seq before calling this function 591 */ 592 int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt, 593 u64 access_mask, unsigned long current_seq) 594 { 595 struct task_struct *owning_process = NULL; 596 struct mm_struct *owning_mm = NULL; 597 struct page **local_page_list = NULL; 598 u64 page_mask, off; 599 int j, k, ret = 0, start_idx, npages = 0, page_shift; 600 unsigned int flags = 0; 601 phys_addr_t p = 0; 602 603 if (access_mask == 0) 604 return -EINVAL; 605 606 if (user_virt < ib_umem_start(umem) || 607 user_virt + bcnt > ib_umem_end(umem)) 608 return -EFAULT; 609 610 local_page_list = (struct page **)__get_free_page(GFP_KERNEL); 611 if (!local_page_list) 612 return -ENOMEM; 613 614 page_shift = umem->page_shift; 615 page_mask = ~(BIT(page_shift) - 1); 616 off = user_virt & (~page_mask); 617 user_virt = user_virt & page_mask; 618 bcnt += off; /* Charge for the first page offset as well. */ 619 620 owning_process = get_pid_task(umem->context->tgid, PIDTYPE_PID); 621 if (owning_process == NULL) { 622 ret = -EINVAL; 623 goto out_no_task; 624 } 625 626 owning_mm = get_task_mm(owning_process); 627 if (owning_mm == NULL) { 628 ret = -ENOENT; 629 goto out_put_task; 630 } 631 632 if (access_mask & ODP_WRITE_ALLOWED_BIT) 633 flags |= FOLL_WRITE; 634 635 start_idx = (user_virt - ib_umem_start(umem)) >> page_shift; 636 k = start_idx; 637 638 while (bcnt > 0) { 639 const size_t gup_num_pages = min_t(size_t, 640 (bcnt + BIT(page_shift) - 1) >> page_shift, 641 PAGE_SIZE / sizeof(struct page *)); 642 643 down_read(&owning_mm->mmap_sem); 644 /* 645 * Note: this might result in redundent page getting. We can 646 * avoid this by checking dma_list to be 0 before calling 647 * get_user_pages. However, this make the code much more 648 * complex (and doesn't gain us much performance in most use 649 * cases). 650 */ 651 npages = get_user_pages_remote(owning_process, owning_mm, 652 user_virt, gup_num_pages, 653 flags, local_page_list, NULL, NULL); 654 up_read(&owning_mm->mmap_sem); 655 656 if (npages < 0) 657 break; 658 659 bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt); 660 mutex_lock(&umem->odp_data->umem_mutex); 661 for (j = 0; j < npages; j++, user_virt += PAGE_SIZE) { 662 if (user_virt & ~page_mask) { 663 p += PAGE_SIZE; 664 if (page_to_phys(local_page_list[j]) != p) { 665 ret = -EFAULT; 666 break; 667 } 668 put_page(local_page_list[j]); 669 continue; 670 } 671 672 ret = ib_umem_odp_map_dma_single_page( 673 umem, k, local_page_list[j], 674 access_mask, current_seq); 675 if (ret < 0) 676 break; 677 678 p = page_to_phys(local_page_list[j]); 679 k++; 680 } 681 mutex_unlock(&umem->odp_data->umem_mutex); 682 683 if (ret < 0) { 684 /* Release left over pages when handling errors. */ 685 for (++j; j < npages; ++j) 686 put_page(local_page_list[j]); 687 break; 688 } 689 } 690 691 if (ret >= 0) { 692 if (npages < 0 && k == start_idx) 693 ret = npages; 694 else 695 ret = k - start_idx; 696 } 697 698 mmput(owning_mm); 699 out_put_task: 700 put_task_struct(owning_process); 701 out_no_task: 702 free_page((unsigned long)local_page_list); 703 return ret; 704 } 705 EXPORT_SYMBOL(ib_umem_odp_map_dma_pages); 706 707 void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt, 708 u64 bound) 709 { 710 int idx; 711 u64 addr; 712 struct ib_device *dev = umem->context->device; 713 714 virt = max_t(u64, virt, ib_umem_start(umem)); 715 bound = min_t(u64, bound, ib_umem_end(umem)); 716 /* Note that during the run of this function, the 717 * notifiers_count of the MR is > 0, preventing any racing 718 * faults from completion. We might be racing with other 719 * invalidations, so we must make sure we free each page only 720 * once. */ 721 mutex_lock(&umem->odp_data->umem_mutex); 722 for (addr = virt; addr < bound; addr += BIT(umem->page_shift)) { 723 idx = (addr - ib_umem_start(umem)) >> umem->page_shift; 724 if (umem->odp_data->page_list[idx]) { 725 struct page *page = umem->odp_data->page_list[idx]; 726 dma_addr_t dma = umem->odp_data->dma_list[idx]; 727 dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK; 728 729 WARN_ON(!dma_addr); 730 731 ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE, 732 DMA_BIDIRECTIONAL); 733 if (dma & ODP_WRITE_ALLOWED_BIT) { 734 struct page *head_page = compound_head(page); 735 /* 736 * set_page_dirty prefers being called with 737 * the page lock. However, MMU notifiers are 738 * called sometimes with and sometimes without 739 * the lock. We rely on the umem_mutex instead 740 * to prevent other mmu notifiers from 741 * continuing and allowing the page mapping to 742 * be removed. 743 */ 744 set_page_dirty(head_page); 745 } 746 /* on demand pinning support */ 747 if (!umem->context->invalidate_range) 748 put_page(page); 749 umem->odp_data->page_list[idx] = NULL; 750 umem->odp_data->dma_list[idx] = 0; 751 umem->npages--; 752 } 753 } 754 mutex_unlock(&umem->odp_data->umem_mutex); 755 } 756 EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages); 757