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 void ib_umem_notifier_invalidate_page(struct mmu_notifier *mn, 170 struct mm_struct *mm, 171 unsigned long address) 172 { 173 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 174 175 if (!context->invalidate_range) 176 return; 177 178 ib_ucontext_notifier_start_account(context); 179 down_read(&context->umem_rwsem); 180 rbt_ib_umem_for_each_in_range(&context->umem_tree, address, 181 address + PAGE_SIZE, 182 invalidate_page_trampoline, NULL); 183 up_read(&context->umem_rwsem); 184 ib_ucontext_notifier_end_account(context); 185 } 186 187 static int invalidate_range_start_trampoline(struct ib_umem *item, u64 start, 188 u64 end, void *cookie) 189 { 190 ib_umem_notifier_start_account(item); 191 item->context->invalidate_range(item, start, end); 192 return 0; 193 } 194 195 static void ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, 196 struct mm_struct *mm, 197 unsigned long start, 198 unsigned long end) 199 { 200 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 201 202 if (!context->invalidate_range) 203 return; 204 205 ib_ucontext_notifier_start_account(context); 206 down_read(&context->umem_rwsem); 207 rbt_ib_umem_for_each_in_range(&context->umem_tree, start, 208 end, 209 invalidate_range_start_trampoline, NULL); 210 up_read(&context->umem_rwsem); 211 } 212 213 static int invalidate_range_end_trampoline(struct ib_umem *item, u64 start, 214 u64 end, void *cookie) 215 { 216 ib_umem_notifier_end_account(item); 217 return 0; 218 } 219 220 static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, 221 struct mm_struct *mm, 222 unsigned long start, 223 unsigned long end) 224 { 225 struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn); 226 227 if (!context->invalidate_range) 228 return; 229 230 down_read(&context->umem_rwsem); 231 rbt_ib_umem_for_each_in_range(&context->umem_tree, start, 232 end, 233 invalidate_range_end_trampoline, NULL); 234 up_read(&context->umem_rwsem); 235 ib_ucontext_notifier_end_account(context); 236 } 237 238 static const struct mmu_notifier_ops ib_umem_notifiers = { 239 .release = ib_umem_notifier_release, 240 .invalidate_page = ib_umem_notifier_invalidate_page, 241 .invalidate_range_start = ib_umem_notifier_invalidate_range_start, 242 .invalidate_range_end = ib_umem_notifier_invalidate_range_end, 243 }; 244 245 struct ib_umem *ib_alloc_odp_umem(struct ib_ucontext *context, 246 unsigned long addr, 247 size_t size) 248 { 249 struct ib_umem *umem; 250 struct ib_umem_odp *odp_data; 251 int pages = size >> PAGE_SHIFT; 252 int ret; 253 254 umem = kzalloc(sizeof(*umem), GFP_KERNEL); 255 if (!umem) 256 return ERR_PTR(-ENOMEM); 257 258 umem->context = context; 259 umem->length = size; 260 umem->address = addr; 261 umem->page_shift = PAGE_SHIFT; 262 umem->writable = 1; 263 264 odp_data = kzalloc(sizeof(*odp_data), GFP_KERNEL); 265 if (!odp_data) { 266 ret = -ENOMEM; 267 goto out_umem; 268 } 269 odp_data->umem = umem; 270 271 mutex_init(&odp_data->umem_mutex); 272 init_completion(&odp_data->notifier_completion); 273 274 odp_data->page_list = vzalloc(pages * sizeof(*odp_data->page_list)); 275 if (!odp_data->page_list) { 276 ret = -ENOMEM; 277 goto out_odp_data; 278 } 279 280 odp_data->dma_list = vzalloc(pages * sizeof(*odp_data->dma_list)); 281 if (!odp_data->dma_list) { 282 ret = -ENOMEM; 283 goto out_page_list; 284 } 285 286 down_write(&context->umem_rwsem); 287 context->odp_mrs_count++; 288 rbt_ib_umem_insert(&odp_data->interval_tree, &context->umem_tree); 289 if (likely(!atomic_read(&context->notifier_count))) 290 odp_data->mn_counters_active = true; 291 else 292 list_add(&odp_data->no_private_counters, 293 &context->no_private_counters); 294 up_write(&context->umem_rwsem); 295 296 umem->odp_data = odp_data; 297 298 return umem; 299 300 out_page_list: 301 vfree(odp_data->page_list); 302 out_odp_data: 303 kfree(odp_data); 304 out_umem: 305 kfree(umem); 306 return ERR_PTR(ret); 307 } 308 EXPORT_SYMBOL(ib_alloc_odp_umem); 309 310 int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem, 311 int access) 312 { 313 int ret_val; 314 struct pid *our_pid; 315 struct mm_struct *mm = get_task_mm(current); 316 317 if (!mm) 318 return -EINVAL; 319 320 if (access & IB_ACCESS_HUGETLB) { 321 struct vm_area_struct *vma; 322 struct hstate *h; 323 324 down_read(&mm->mmap_sem); 325 vma = find_vma(mm, ib_umem_start(umem)); 326 if (!vma || !is_vm_hugetlb_page(vma)) { 327 up_read(&mm->mmap_sem); 328 return -EINVAL; 329 } 330 h = hstate_vma(vma); 331 umem->page_shift = huge_page_shift(h); 332 up_read(&mm->mmap_sem); 333 umem->hugetlb = 1; 334 } else { 335 umem->hugetlb = 0; 336 } 337 338 /* Prevent creating ODP MRs in child processes */ 339 rcu_read_lock(); 340 our_pid = get_task_pid(current->group_leader, PIDTYPE_PID); 341 rcu_read_unlock(); 342 put_pid(our_pid); 343 if (context->tgid != our_pid) { 344 ret_val = -EINVAL; 345 goto out_mm; 346 } 347 348 umem->odp_data = kzalloc(sizeof(*umem->odp_data), GFP_KERNEL); 349 if (!umem->odp_data) { 350 ret_val = -ENOMEM; 351 goto out_mm; 352 } 353 umem->odp_data->umem = umem; 354 355 mutex_init(&umem->odp_data->umem_mutex); 356 357 init_completion(&umem->odp_data->notifier_completion); 358 359 if (ib_umem_num_pages(umem)) { 360 umem->odp_data->page_list = vzalloc(ib_umem_num_pages(umem) * 361 sizeof(*umem->odp_data->page_list)); 362 if (!umem->odp_data->page_list) { 363 ret_val = -ENOMEM; 364 goto out_odp_data; 365 } 366 367 umem->odp_data->dma_list = vzalloc(ib_umem_num_pages(umem) * 368 sizeof(*umem->odp_data->dma_list)); 369 if (!umem->odp_data->dma_list) { 370 ret_val = -ENOMEM; 371 goto out_page_list; 372 } 373 } 374 375 /* 376 * When using MMU notifiers, we will get a 377 * notification before the "current" task (and MM) is 378 * destroyed. We use the umem_rwsem semaphore to synchronize. 379 */ 380 down_write(&context->umem_rwsem); 381 context->odp_mrs_count++; 382 if (likely(ib_umem_start(umem) != ib_umem_end(umem))) 383 rbt_ib_umem_insert(&umem->odp_data->interval_tree, 384 &context->umem_tree); 385 if (likely(!atomic_read(&context->notifier_count)) || 386 context->odp_mrs_count == 1) 387 umem->odp_data->mn_counters_active = true; 388 else 389 list_add(&umem->odp_data->no_private_counters, 390 &context->no_private_counters); 391 downgrade_write(&context->umem_rwsem); 392 393 if (context->odp_mrs_count == 1) { 394 /* 395 * Note that at this point, no MMU notifier is running 396 * for this context! 397 */ 398 atomic_set(&context->notifier_count, 0); 399 INIT_HLIST_NODE(&context->mn.hlist); 400 context->mn.ops = &ib_umem_notifiers; 401 /* 402 * Lock-dep detects a false positive for mmap_sem vs. 403 * umem_rwsem, due to not grasping downgrade_write correctly. 404 */ 405 lockdep_off(); 406 ret_val = mmu_notifier_register(&context->mn, mm); 407 lockdep_on(); 408 if (ret_val) { 409 pr_err("Failed to register mmu_notifier %d\n", ret_val); 410 ret_val = -EBUSY; 411 goto out_mutex; 412 } 413 } 414 415 up_read(&context->umem_rwsem); 416 417 /* 418 * Note that doing an mmput can cause a notifier for the relevant mm. 419 * If the notifier is called while we hold the umem_rwsem, this will 420 * cause a deadlock. Therefore, we release the reference only after we 421 * released the semaphore. 422 */ 423 mmput(mm); 424 return 0; 425 426 out_mutex: 427 up_read(&context->umem_rwsem); 428 vfree(umem->odp_data->dma_list); 429 out_page_list: 430 vfree(umem->odp_data->page_list); 431 out_odp_data: 432 kfree(umem->odp_data); 433 out_mm: 434 mmput(mm); 435 return ret_val; 436 } 437 438 void ib_umem_odp_release(struct ib_umem *umem) 439 { 440 struct ib_ucontext *context = umem->context; 441 442 /* 443 * Ensure that no more pages are mapped in the umem. 444 * 445 * It is the driver's responsibility to ensure, before calling us, 446 * that the hardware will not attempt to access the MR any more. 447 */ 448 ib_umem_odp_unmap_dma_pages(umem, ib_umem_start(umem), 449 ib_umem_end(umem)); 450 451 down_write(&context->umem_rwsem); 452 if (likely(ib_umem_start(umem) != ib_umem_end(umem))) 453 rbt_ib_umem_remove(&umem->odp_data->interval_tree, 454 &context->umem_tree); 455 context->odp_mrs_count--; 456 if (!umem->odp_data->mn_counters_active) { 457 list_del(&umem->odp_data->no_private_counters); 458 complete_all(&umem->odp_data->notifier_completion); 459 } 460 461 /* 462 * Downgrade the lock to a read lock. This ensures that the notifiers 463 * (who lock the mutex for reading) will be able to finish, and we 464 * will be able to enventually obtain the mmu notifiers SRCU. Note 465 * that since we are doing it atomically, no other user could register 466 * and unregister while we do the check. 467 */ 468 downgrade_write(&context->umem_rwsem); 469 if (!context->odp_mrs_count) { 470 struct task_struct *owning_process = NULL; 471 struct mm_struct *owning_mm = NULL; 472 473 owning_process = get_pid_task(context->tgid, 474 PIDTYPE_PID); 475 if (owning_process == NULL) 476 /* 477 * The process is already dead, notifier were removed 478 * already. 479 */ 480 goto out; 481 482 owning_mm = get_task_mm(owning_process); 483 if (owning_mm == NULL) 484 /* 485 * The process' mm is already dead, notifier were 486 * removed already. 487 */ 488 goto out_put_task; 489 mmu_notifier_unregister(&context->mn, owning_mm); 490 491 mmput(owning_mm); 492 493 out_put_task: 494 put_task_struct(owning_process); 495 } 496 out: 497 up_read(&context->umem_rwsem); 498 499 vfree(umem->odp_data->dma_list); 500 vfree(umem->odp_data->page_list); 501 kfree(umem->odp_data); 502 kfree(umem); 503 } 504 505 /* 506 * Map for DMA and insert a single page into the on-demand paging page tables. 507 * 508 * @umem: the umem to insert the page to. 509 * @page_index: index in the umem to add the page to. 510 * @page: the page struct to map and add. 511 * @access_mask: access permissions needed for this page. 512 * @current_seq: sequence number for synchronization with invalidations. 513 * the sequence number is taken from 514 * umem->odp_data->notifiers_seq. 515 * 516 * The function returns -EFAULT if the DMA mapping operation fails. It returns 517 * -EAGAIN if a concurrent invalidation prevents us from updating the page. 518 * 519 * The page is released via put_page even if the operation failed. For 520 * on-demand pinning, the page is released whenever it isn't stored in the 521 * umem. 522 */ 523 static int ib_umem_odp_map_dma_single_page( 524 struct ib_umem *umem, 525 int page_index, 526 struct page *page, 527 u64 access_mask, 528 unsigned long current_seq) 529 { 530 struct ib_device *dev = umem->context->device; 531 dma_addr_t dma_addr; 532 int stored_page = 0; 533 int remove_existing_mapping = 0; 534 int ret = 0; 535 536 /* 537 * Note: we avoid writing if seq is different from the initial seq, to 538 * handle case of a racing notifier. This check also allows us to bail 539 * early if we have a notifier running in parallel with us. 540 */ 541 if (ib_umem_mmu_notifier_retry(umem, current_seq)) { 542 ret = -EAGAIN; 543 goto out; 544 } 545 if (!(umem->odp_data->dma_list[page_index])) { 546 dma_addr = ib_dma_map_page(dev, 547 page, 548 0, BIT(umem->page_shift), 549 DMA_BIDIRECTIONAL); 550 if (ib_dma_mapping_error(dev, dma_addr)) { 551 ret = -EFAULT; 552 goto out; 553 } 554 umem->odp_data->dma_list[page_index] = dma_addr | access_mask; 555 umem->odp_data->page_list[page_index] = page; 556 umem->npages++; 557 stored_page = 1; 558 } else if (umem->odp_data->page_list[page_index] == page) { 559 umem->odp_data->dma_list[page_index] |= access_mask; 560 } else { 561 pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n", 562 umem->odp_data->page_list[page_index], page); 563 /* Better remove the mapping now, to prevent any further 564 * damage. */ 565 remove_existing_mapping = 1; 566 } 567 568 out: 569 /* On Demand Paging - avoid pinning the page */ 570 if (umem->context->invalidate_range || !stored_page) 571 put_page(page); 572 573 if (remove_existing_mapping && umem->context->invalidate_range) { 574 invalidate_page_trampoline( 575 umem, 576 ib_umem_start(umem) + (page_index >> umem->page_shift), 577 ib_umem_start(umem) + ((page_index + 1) >> 578 umem->page_shift), 579 NULL); 580 ret = -EAGAIN; 581 } 582 583 return ret; 584 } 585 586 /** 587 * ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR. 588 * 589 * Pins the range of pages passed in the argument, and maps them to 590 * DMA addresses. The DMA addresses of the mapped pages is updated in 591 * umem->odp_data->dma_list. 592 * 593 * Returns the number of pages mapped in success, negative error code 594 * for failure. 595 * An -EAGAIN error code is returned when a concurrent mmu notifier prevents 596 * the function from completing its task. 597 * An -ENOENT error code indicates that userspace process is being terminated 598 * and mm was already destroyed. 599 * @umem: the umem to map and pin 600 * @user_virt: the address from which we need to map. 601 * @bcnt: the minimal number of bytes to pin and map. The mapping might be 602 * bigger due to alignment, and may also be smaller in case of an error 603 * pinning or mapping a page. The actual pages mapped is returned in 604 * the return value. 605 * @access_mask: bit mask of the requested access permissions for the given 606 * range. 607 * @current_seq: the MMU notifiers sequance value for synchronization with 608 * invalidations. the sequance number is read from 609 * umem->odp_data->notifiers_seq before calling this function 610 */ 611 int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt, 612 u64 access_mask, unsigned long current_seq) 613 { 614 struct task_struct *owning_process = NULL; 615 struct mm_struct *owning_mm = NULL; 616 struct page **local_page_list = NULL; 617 u64 page_mask, off; 618 int j, k, ret = 0, start_idx, npages = 0, page_shift; 619 unsigned int flags = 0; 620 phys_addr_t p = 0; 621 622 if (access_mask == 0) 623 return -EINVAL; 624 625 if (user_virt < ib_umem_start(umem) || 626 user_virt + bcnt > ib_umem_end(umem)) 627 return -EFAULT; 628 629 local_page_list = (struct page **)__get_free_page(GFP_KERNEL); 630 if (!local_page_list) 631 return -ENOMEM; 632 633 page_shift = umem->page_shift; 634 page_mask = ~(BIT(page_shift) - 1); 635 off = user_virt & (~page_mask); 636 user_virt = user_virt & page_mask; 637 bcnt += off; /* Charge for the first page offset as well. */ 638 639 owning_process = get_pid_task(umem->context->tgid, PIDTYPE_PID); 640 if (owning_process == NULL) { 641 ret = -EINVAL; 642 goto out_no_task; 643 } 644 645 owning_mm = get_task_mm(owning_process); 646 if (owning_mm == NULL) { 647 ret = -ENOENT; 648 goto out_put_task; 649 } 650 651 if (access_mask & ODP_WRITE_ALLOWED_BIT) 652 flags |= FOLL_WRITE; 653 654 start_idx = (user_virt - ib_umem_start(umem)) >> page_shift; 655 k = start_idx; 656 657 while (bcnt > 0) { 658 const size_t gup_num_pages = min_t(size_t, 659 (bcnt + BIT(page_shift) - 1) >> page_shift, 660 PAGE_SIZE / sizeof(struct page *)); 661 662 down_read(&owning_mm->mmap_sem); 663 /* 664 * Note: this might result in redundent page getting. We can 665 * avoid this by checking dma_list to be 0 before calling 666 * get_user_pages. However, this make the code much more 667 * complex (and doesn't gain us much performance in most use 668 * cases). 669 */ 670 npages = get_user_pages_remote(owning_process, owning_mm, 671 user_virt, gup_num_pages, 672 flags, local_page_list, NULL, NULL); 673 up_read(&owning_mm->mmap_sem); 674 675 if (npages < 0) 676 break; 677 678 bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt); 679 mutex_lock(&umem->odp_data->umem_mutex); 680 for (j = 0; j < npages; j++, user_virt += PAGE_SIZE) { 681 if (user_virt & ~page_mask) { 682 p += PAGE_SIZE; 683 if (page_to_phys(local_page_list[j]) != p) { 684 ret = -EFAULT; 685 break; 686 } 687 put_page(local_page_list[j]); 688 continue; 689 } 690 691 ret = ib_umem_odp_map_dma_single_page( 692 umem, k, local_page_list[j], 693 access_mask, current_seq); 694 if (ret < 0) 695 break; 696 697 p = page_to_phys(local_page_list[j]); 698 k++; 699 } 700 mutex_unlock(&umem->odp_data->umem_mutex); 701 702 if (ret < 0) { 703 /* Release left over pages when handling errors. */ 704 for (++j; j < npages; ++j) 705 put_page(local_page_list[j]); 706 break; 707 } 708 } 709 710 if (ret >= 0) { 711 if (npages < 0 && k == start_idx) 712 ret = npages; 713 else 714 ret = k - start_idx; 715 } 716 717 mmput(owning_mm); 718 out_put_task: 719 put_task_struct(owning_process); 720 out_no_task: 721 free_page((unsigned long)local_page_list); 722 return ret; 723 } 724 EXPORT_SYMBOL(ib_umem_odp_map_dma_pages); 725 726 void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt, 727 u64 bound) 728 { 729 int idx; 730 u64 addr; 731 struct ib_device *dev = umem->context->device; 732 733 virt = max_t(u64, virt, ib_umem_start(umem)); 734 bound = min_t(u64, bound, ib_umem_end(umem)); 735 /* Note that during the run of this function, the 736 * notifiers_count of the MR is > 0, preventing any racing 737 * faults from completion. We might be racing with other 738 * invalidations, so we must make sure we free each page only 739 * once. */ 740 mutex_lock(&umem->odp_data->umem_mutex); 741 for (addr = virt; addr < bound; addr += BIT(umem->page_shift)) { 742 idx = (addr - ib_umem_start(umem)) >> umem->page_shift; 743 if (umem->odp_data->page_list[idx]) { 744 struct page *page = umem->odp_data->page_list[idx]; 745 dma_addr_t dma = umem->odp_data->dma_list[idx]; 746 dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK; 747 748 WARN_ON(!dma_addr); 749 750 ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE, 751 DMA_BIDIRECTIONAL); 752 if (dma & ODP_WRITE_ALLOWED_BIT) { 753 struct page *head_page = compound_head(page); 754 /* 755 * set_page_dirty prefers being called with 756 * the page lock. However, MMU notifiers are 757 * called sometimes with and sometimes without 758 * the lock. We rely on the umem_mutex instead 759 * to prevent other mmu notifiers from 760 * continuing and allowing the page mapping to 761 * be removed. 762 */ 763 set_page_dirty(head_page); 764 } 765 /* on demand pinning support */ 766 if (!umem->context->invalidate_range) 767 put_page(page); 768 umem->odp_data->page_list[idx] = NULL; 769 umem->odp_data->dma_list[idx] = 0; 770 umem->npages--; 771 } 772 } 773 mutex_unlock(&umem->odp_data->umem_mutex); 774 } 775 EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages); 776