1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */ 2 /************************************************************************** 3 * 4 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA 5 * All Rights Reserved. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a 8 * copy of this software and associated documentation files (the 9 * "Software"), to deal in the Software without restriction, including 10 * without limitation the rights to use, copy, modify, merge, publish, 11 * distribute, sub license, and/or sell copies of the Software, and to 12 * permit persons to whom the Software is furnished to do so, subject to 13 * the following conditions: 14 * 15 * The above copyright notice and this permission notice (including the 16 * next paragraph) shall be included in all copies or substantial portions 17 * of the Software. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 25 * USE OR OTHER DEALINGS IN THE SOFTWARE. 26 * 27 **************************************************************************/ 28 /* 29 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> 30 */ 31 32 #define pr_fmt(fmt) "[TTM] " fmt 33 34 #include <drm/ttm/ttm_bo.h> 35 #include <drm/ttm/ttm_placement.h> 36 #include <drm/ttm/ttm_tt.h> 37 38 #include <drm/drm_drv.h> 39 #include <drm/drm_managed.h> 40 41 #ifdef __linux__ 42 43 static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, 44 struct vm_fault *vmf) 45 { 46 long err = 0; 47 48 /* 49 * Quick non-stalling check for idle. 50 */ 51 if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_KERNEL)) 52 return 0; 53 54 /* 55 * If possible, avoid waiting for GPU with mmap_lock 56 * held. We only do this if the fault allows retry and this 57 * is the first attempt. 58 */ 59 if (fault_flag_allow_retry_first(vmf->flags)) { 60 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT) 61 return VM_FAULT_RETRY; 62 63 ttm_bo_get(bo); 64 mmap_read_unlock(vmf->vma->vm_mm); 65 (void)dma_resv_wait_timeout(bo->base.resv, 66 DMA_RESV_USAGE_KERNEL, true, 67 MAX_SCHEDULE_TIMEOUT); 68 dma_resv_unlock(bo->base.resv); 69 ttm_bo_put(bo); 70 return VM_FAULT_RETRY; 71 } 72 73 /* 74 * Ordinary wait. 75 */ 76 err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_KERNEL, true, 77 MAX_SCHEDULE_TIMEOUT); 78 if (unlikely(err < 0)) { 79 return (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS : 80 VM_FAULT_NOPAGE; 81 } 82 83 return 0; 84 } 85 86 static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, 87 unsigned long page_offset) 88 { 89 struct ttm_device *bdev = bo->bdev; 90 91 if (bdev->funcs->io_mem_pfn) 92 return bdev->funcs->io_mem_pfn(bo, page_offset); 93 94 return (bo->resource->bus.offset >> PAGE_SHIFT) + page_offset; 95 } 96 97 /** 98 * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback 99 * @bo: The buffer object 100 * @vmf: The fault structure handed to the callback 101 * 102 * vm callbacks like fault() and *_mkwrite() allow for the mmap_lock to be dropped 103 * during long waits, and after the wait the callback will be restarted. This 104 * is to allow other threads using the same virtual memory space concurrent 105 * access to map(), unmap() completely unrelated buffer objects. TTM buffer 106 * object reservations sometimes wait for GPU and should therefore be 107 * considered long waits. This function reserves the buffer object interruptibly 108 * taking this into account. Starvation is avoided by the vm system not 109 * allowing too many repeated restarts. 110 * This function is intended to be used in customized fault() and _mkwrite() 111 * handlers. 112 * 113 * Return: 114 * 0 on success and the bo was reserved. 115 * VM_FAULT_RETRY if blocking wait. 116 * VM_FAULT_NOPAGE if blocking wait and retrying was not allowed. 117 */ 118 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, 119 struct vm_fault *vmf) 120 { 121 /* 122 * Work around locking order reversal in fault / nopfn 123 * between mmap_lock and bo_reserve: Perform a trylock operation 124 * for reserve, and if it fails, retry the fault after waiting 125 * for the buffer to become unreserved. 126 */ 127 if (unlikely(!dma_resv_trylock(bo->base.resv))) { 128 /* 129 * If the fault allows retry and this is the first 130 * fault attempt, we try to release the mmap_lock 131 * before waiting 132 */ 133 if (fault_flag_allow_retry_first(vmf->flags)) { 134 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { 135 ttm_bo_get(bo); 136 mmap_read_unlock(vmf->vma->vm_mm); 137 if (!dma_resv_lock_interruptible(bo->base.resv, 138 NULL)) 139 dma_resv_unlock(bo->base.resv); 140 ttm_bo_put(bo); 141 } 142 143 return VM_FAULT_RETRY; 144 } 145 146 if (dma_resv_lock_interruptible(bo->base.resv, NULL)) 147 return VM_FAULT_NOPAGE; 148 } 149 150 /* 151 * Refuse to fault imported pages. This should be handled 152 * (if at all) by redirecting mmap to the exporter. 153 */ 154 if (bo->ttm && (bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) { 155 if (!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)) { 156 dma_resv_unlock(bo->base.resv); 157 return VM_FAULT_SIGBUS; 158 } 159 } 160 161 return 0; 162 } 163 EXPORT_SYMBOL(ttm_bo_vm_reserve); 164 165 /** 166 * ttm_bo_vm_fault_reserved - TTM fault helper 167 * @vmf: The struct vm_fault given as argument to the fault callback 168 * @prot: The page protection to be used for this memory area. 169 * @num_prefault: Maximum number of prefault pages. The caller may want to 170 * specify this based on madvice settings and the size of the GPU object 171 * backed by the memory. 172 * 173 * This function inserts one or more page table entries pointing to the 174 * memory backing the buffer object, and then returns a return code 175 * instructing the caller to retry the page access. 176 * 177 * Return: 178 * VM_FAULT_NOPAGE on success or pending signal 179 * VM_FAULT_SIGBUS on unspecified error 180 * VM_FAULT_OOM on out-of-memory 181 * VM_FAULT_RETRY if retryable wait 182 */ 183 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, 184 pgprot_t prot, 185 pgoff_t num_prefault) 186 { 187 struct vm_area_struct *vma = vmf->vma; 188 struct ttm_buffer_object *bo = vma->vm_private_data; 189 struct ttm_device *bdev = bo->bdev; 190 unsigned long page_offset; 191 unsigned long page_last; 192 unsigned long pfn; 193 struct ttm_tt *ttm = NULL; 194 struct vm_page *page; 195 int err; 196 pgoff_t i; 197 vm_fault_t ret = VM_FAULT_NOPAGE; 198 unsigned long address = vmf->address; 199 200 /* 201 * Wait for buffer data in transit, due to a pipelined 202 * move. 203 */ 204 ret = ttm_bo_vm_fault_idle(bo, vmf); 205 if (unlikely(ret != 0)) 206 return ret; 207 208 err = ttm_mem_io_reserve(bdev, bo->resource); 209 if (unlikely(err != 0)) 210 return VM_FAULT_SIGBUS; 211 212 page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) + 213 vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node); 214 page_last = vma_pages(vma) + vma->vm_pgoff - 215 drm_vma_node_start(&bo->base.vma_node); 216 217 if (unlikely(page_offset >= PFN_UP(bo->base.size))) 218 return VM_FAULT_SIGBUS; 219 220 prot = ttm_io_prot(bo, bo->resource, prot); 221 if (!bo->resource->bus.is_iomem) { 222 struct ttm_operation_ctx ctx = { 223 .interruptible = true, 224 .no_wait_gpu = false, 225 .force_alloc = true 226 }; 227 228 ttm = bo->ttm; 229 err = ttm_tt_populate(bdev, bo->ttm, &ctx); 230 if (err) { 231 if (err == -EINTR || err == -ERESTARTSYS || 232 err == -EAGAIN) 233 return VM_FAULT_NOPAGE; 234 235 pr_debug("TTM fault hit %pe.\n", ERR_PTR(err)); 236 return VM_FAULT_SIGBUS; 237 } 238 } else { 239 /* Iomem should not be marked encrypted */ 240 prot = pgprot_decrypted(prot); 241 } 242 243 /* 244 * Speculatively prefault a number of pages. Only error on 245 * first page. 246 */ 247 for (i = 0; i < num_prefault; ++i) { 248 if (bo->resource->bus.is_iomem) { 249 pfn = ttm_bo_io_mem_pfn(bo, page_offset); 250 } else { 251 page = ttm->pages[page_offset]; 252 if (unlikely(!page && i == 0)) { 253 return VM_FAULT_OOM; 254 } else if (unlikely(!page)) { 255 break; 256 } 257 pfn = page_to_pfn(page); 258 } 259 260 /* 261 * Note that the value of @prot at this point may differ from 262 * the value of @vma->vm_page_prot in the caching- and 263 * encryption bits. This is because the exact location of the 264 * data may not be known at mmap() time and may also change 265 * at arbitrary times while the data is mmap'ed. 266 * See vmf_insert_pfn_prot() for a discussion. 267 */ 268 ret = vmf_insert_pfn_prot(vma, address, pfn, prot); 269 270 /* Never error on prefaulted PTEs */ 271 if (unlikely((ret & VM_FAULT_ERROR))) { 272 if (i == 0) 273 return VM_FAULT_NOPAGE; 274 else 275 break; 276 } 277 278 address += PAGE_SIZE; 279 if (unlikely(++page_offset >= page_last)) 280 break; 281 } 282 return ret; 283 } 284 EXPORT_SYMBOL(ttm_bo_vm_fault_reserved); 285 286 static void ttm_bo_release_dummy_page(struct drm_device *dev, void *res) 287 { 288 struct page *dummy_page = (struct page *)res; 289 290 __free_page(dummy_page); 291 } 292 293 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot) 294 { 295 struct vm_area_struct *vma = vmf->vma; 296 struct ttm_buffer_object *bo = vma->vm_private_data; 297 struct drm_device *ddev = bo->base.dev; 298 vm_fault_t ret = VM_FAULT_NOPAGE; 299 unsigned long address; 300 unsigned long pfn; 301 struct page *page; 302 303 /* Allocate new dummy page to map all the VA range in this VMA to it*/ 304 page = alloc_page(GFP_KERNEL | __GFP_ZERO); 305 if (!page) 306 return VM_FAULT_OOM; 307 308 /* Set the page to be freed using drmm release action */ 309 if (drmm_add_action_or_reset(ddev, ttm_bo_release_dummy_page, page)) 310 return VM_FAULT_OOM; 311 312 pfn = page_to_pfn(page); 313 314 /* Prefault the entire VMA range right away to avoid further faults */ 315 for (address = vma->vm_start; address < vma->vm_end; 316 address += PAGE_SIZE) 317 ret = vmf_insert_pfn_prot(vma, address, pfn, prot); 318 319 return ret; 320 } 321 EXPORT_SYMBOL(ttm_bo_vm_dummy_page); 322 323 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) 324 { 325 struct vm_area_struct *vma = vmf->vma; 326 pgprot_t prot; 327 struct ttm_buffer_object *bo = vma->vm_private_data; 328 struct drm_device *ddev = bo->base.dev; 329 vm_fault_t ret; 330 int idx; 331 332 ret = ttm_bo_vm_reserve(bo, vmf); 333 if (ret) 334 return ret; 335 336 prot = vma->vm_page_prot; 337 if (drm_dev_enter(ddev, &idx)) { 338 ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); 339 drm_dev_exit(idx); 340 } else { 341 ret = ttm_bo_vm_dummy_page(vmf, prot); 342 } 343 if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) 344 return ret; 345 346 dma_resv_unlock(bo->base.resv); 347 348 return ret; 349 } 350 EXPORT_SYMBOL(ttm_bo_vm_fault); 351 352 #else /* !__linux__ */ 353 354 static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, 355 struct uvm_faultinfo *ufi) 356 { 357 long err = 0; 358 359 /* 360 * Quick non-stalling check for idle. 361 */ 362 if (dma_resv_test_signaled(bo->base.resv, DMA_RESV_USAGE_KERNEL)) 363 return 0; 364 365 #ifdef __linux__ 366 /* 367 * If possible, avoid waiting for GPU with mmap_lock 368 * held. We only do this if the fault allows retry and this 369 * is the first attempt. 370 */ 371 if (fault_flag_allow_retry_first(vmf->flags)) { 372 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT) 373 return VM_FAULT_RETRY; 374 375 ttm_bo_get(bo); 376 mmap_read_unlock(vmf->vma->vm_mm); 377 (void) dma_fence_wait(bo->moving, true); 378 (void)dma_resv_wait_timeout(bo->base.resv, 379 DMA_RESV_USAGE_KERNEL, true, 380 MAX_SCHEDULE_TIMEOUT); 381 dma_resv_unlock(bo->base.resv); 382 ttm_bo_put(bo); 383 return VM_FAULT_RETRY; 384 } 385 #endif 386 387 /* 388 * Ordinary wait. 389 */ 390 err = dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_KERNEL, true, 391 MAX_SCHEDULE_TIMEOUT); 392 if (unlikely(err < 0)) { 393 return (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS : 394 VM_FAULT_NOPAGE; 395 } 396 397 return 0; 398 } 399 400 static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, 401 unsigned long page_offset) 402 { 403 struct ttm_device *bdev = bo->bdev; 404 405 if (bdev->funcs->io_mem_pfn) 406 return bdev->funcs->io_mem_pfn(bo, page_offset); 407 408 return (bo->resource->bus.offset >> PAGE_SHIFT) + page_offset; 409 } 410 411 /** 412 * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback 413 * @bo: The buffer object 414 * @vmf: The fault structure handed to the callback 415 * 416 * vm callbacks like fault() and *_mkwrite() allow for the mmap_lock to be dropped 417 * during long waits, and after the wait the callback will be restarted. This 418 * is to allow other threads using the same virtual memory space concurrent 419 * access to map(), unmap() completely unrelated buffer objects. TTM buffer 420 * object reservations sometimes wait for GPU and should therefore be 421 * considered long waits. This function reserves the buffer object interruptibly 422 * taking this into account. Starvation is avoided by the vm system not 423 * allowing too many repeated restarts. 424 * This function is intended to be used in customized fault() and _mkwrite() 425 * handlers. 426 * 427 * Return: 428 * 0 on success and the bo was reserved. 429 * VM_FAULT_RETRY if blocking wait. 430 * VM_FAULT_NOPAGE if blocking wait and retrying was not allowed. 431 */ 432 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo) 433 { 434 /* 435 * Work around locking order reversal in fault / nopfn 436 * between mmap_lock and bo_reserve: Perform a trylock operation 437 * for reserve, and if it fails, retry the fault after waiting 438 * for the buffer to become unreserved. 439 */ 440 if (unlikely(!dma_resv_trylock(bo->base.resv))) { 441 #ifdef __linux__ 442 /* 443 * If the fault allows retry and this is the first 444 * fault attempt, we try to release the mmap_lock 445 * before waiting 446 */ 447 if (fault_flag_allow_retry_first(vmf->flags)) { 448 if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { 449 ttm_bo_get(bo); 450 mmap_read_unlock(vmf->vma->vm_mm); 451 if (!dma_resv_lock_interruptible(bo->base.resv, 452 NULL)) 453 dma_resv_unlock(bo->base.resv); 454 ttm_bo_put(bo); 455 } 456 457 return VM_FAULT_RETRY; 458 } 459 #endif 460 461 if (dma_resv_lock_interruptible(bo->base.resv, NULL)) 462 return VM_FAULT_NOPAGE; 463 } 464 465 /* 466 * Refuse to fault imported pages. This should be handled 467 * (if at all) by redirecting mmap to the exporter. 468 */ 469 if (bo->ttm && (bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) { 470 if (!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)) { 471 dma_resv_unlock(bo->base.resv); 472 return VM_FAULT_SIGBUS; 473 } 474 } 475 476 return 0; 477 } 478 479 vm_fault_t ttm_bo_vm_fault_reserved(struct uvm_faultinfo *ufi, 480 vaddr_t vaddr, 481 pgoff_t num_prefault, 482 pgoff_t fault_page_size) 483 { 484 struct uvm_object *uobj = ufi->entry->object.uvm_obj; 485 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)uobj; 486 struct ttm_device *bdev = bo->bdev; 487 unsigned long page_offset; 488 unsigned long page_last; 489 unsigned long pfn; 490 struct ttm_tt *ttm = NULL; 491 struct vm_page *page; 492 bus_addr_t addr; 493 paddr_t paddr; 494 vm_prot_t prot; 495 int pmap_flags; 496 int err; 497 pgoff_t i; 498 vm_fault_t ret = VM_FAULT_NOPAGE; 499 unsigned long address = (unsigned long)vaddr; 500 501 /* 502 * Wait for buffer data in transit, due to a pipelined 503 * move. 504 */ 505 ret = ttm_bo_vm_fault_idle(bo, ufi); 506 if (unlikely(ret != 0)) 507 return ret; 508 ret = VM_FAULT_NOPAGE; 509 510 err = ttm_mem_io_reserve(bdev, bo->resource); 511 if (unlikely(err != 0)) 512 return VM_FAULT_SIGBUS; 513 514 page_offset = ((address - ufi->entry->start) >> PAGE_SHIFT) + 515 drm_vma_node_start(&bo->base.vma_node) - (ufi->entry->offset >> PAGE_SHIFT); 516 page_last = ((ufi->entry->end - ufi->entry->start) >> PAGE_SHIFT) + 517 drm_vma_node_start(&bo->base.vma_node) - (ufi->entry->offset >> PAGE_SHIFT); 518 519 if (unlikely(page_offset >= PFN_UP(bo->base.size))) 520 return VM_FAULT_SIGBUS; 521 522 prot = ufi->entry->protection; 523 pmap_flags = ttm_io_prot(bo, bo->resource, 0); 524 if (!bo->resource->bus.is_iomem) { 525 struct ttm_operation_ctx ctx = { 526 .interruptible = true, 527 .no_wait_gpu = false, 528 .force_alloc = true 529 }; 530 531 ttm = bo->ttm; 532 err = ttm_tt_populate(bdev, bo->ttm, &ctx); 533 if (err) { 534 if (err == -EINTR || err == -ERESTARTSYS || 535 err == -EAGAIN) 536 return VM_FAULT_NOPAGE; 537 538 pr_debug("TTM fault hit %pe.\n", ERR_PTR(err)); 539 return VM_FAULT_SIGBUS; 540 } 541 } 542 543 #ifdef __linux__ 544 /* We don't prefault on huge faults. Yet. */ 545 if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && fault_page_size != 1) 546 return ttm_bo_vm_insert_huge(vmf, bo, page_offset, 547 fault_page_size, prot); 548 #endif 549 550 /* 551 * Speculatively prefault a number of pages. Only error on 552 * first page. 553 */ 554 for (i = 0; i < num_prefault; ++i) { 555 if (bo->resource->bus.is_iomem) { 556 pfn = ttm_bo_io_mem_pfn(bo, page_offset); 557 addr = pfn << PAGE_SHIFT; 558 paddr = bus_space_mmap(bdev->memt, addr, 0, prot, 0); 559 } else { 560 page = ttm->pages[page_offset]; 561 if (unlikely(!page && i == 0)) { 562 return VM_FAULT_OOM; 563 } else if (unlikely(!page)) { 564 break; 565 } 566 paddr = VM_PAGE_TO_PHYS(page); 567 } 568 569 err = pmap_enter(ufi->orig_map->pmap, address, 570 paddr | pmap_flags, prot, PMAP_CANFAIL | prot); 571 572 /* Never error on prefaulted PTEs */ 573 if (unlikely(err)) { 574 ret = VM_FAULT_OOM; 575 if (i == 0) 576 return VM_FAULT_NOPAGE; 577 else 578 break; 579 } 580 581 address += PAGE_SIZE; 582 if (unlikely(++page_offset >= page_last)) 583 break; 584 } 585 pmap_update(ufi->orig_map->pmap); 586 return ret; 587 } 588 EXPORT_SYMBOL(ttm_bo_vm_fault_reserved); 589 590 int 591 ttm_bo_vm_fault(struct uvm_faultinfo *ufi, vaddr_t vaddr, vm_page_t *pps, 592 int npages, int centeridx, vm_fault_t fault_type, 593 vm_prot_t access_type, int flags) 594 { 595 struct uvm_object *uobj = ufi->entry->object.uvm_obj; 596 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)uobj; 597 vm_fault_t ret; 598 599 ret = ttm_bo_vm_reserve(bo); 600 if (ret) { 601 goto out; 602 } 603 604 ret = ttm_bo_vm_fault_reserved(ufi, vaddr, TTM_BO_VM_NUM_PREFAULT, 1); 605 dma_resv_unlock(bo->base.resv); 606 out: 607 switch (ret) { 608 case VM_FAULT_NOPAGE: 609 ret = 0; 610 break; 611 case VM_FAULT_RETRY: 612 ret = ERESTART; 613 break; 614 default: 615 ret = EACCES; 616 break; 617 } 618 uvmfault_unlockall(ufi, NULL, uobj); 619 return ret; 620 } 621 EXPORT_SYMBOL(ttm_bo_vm_fault); 622 623 #endif /* !__linux__ */ 624 625 #ifdef notyet 626 void ttm_bo_vm_open(struct vm_area_struct *vma) 627 { 628 struct ttm_buffer_object *bo = vma->vm_private_data; 629 630 WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping); 631 632 ttm_bo_get(bo); 633 } 634 EXPORT_SYMBOL(ttm_bo_vm_open); 635 636 void ttm_bo_vm_close(struct vm_area_struct *vma) 637 { 638 struct ttm_buffer_object *bo = vma->vm_private_data; 639 640 ttm_bo_put(bo); 641 vma->vm_private_data = NULL; 642 } 643 EXPORT_SYMBOL(ttm_bo_vm_close); 644 645 static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, 646 unsigned long offset, 647 uint8_t *buf, int len, int write) 648 { 649 unsigned long page = offset >> PAGE_SHIFT; 650 unsigned long bytes_left = len; 651 int ret; 652 653 /* Copy a page at a time, that way no extra virtual address 654 * mapping is needed 655 */ 656 offset -= page << PAGE_SHIFT; 657 do { 658 unsigned long bytes = min(bytes_left, PAGE_SIZE - offset); 659 struct ttm_bo_kmap_obj map; 660 void *ptr; 661 bool is_iomem; 662 663 ret = ttm_bo_kmap(bo, page, 1, &map); 664 if (ret) 665 return ret; 666 667 ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset; 668 WARN_ON_ONCE(is_iomem); 669 if (write) 670 memcpy(ptr, buf, bytes); 671 else 672 memcpy(buf, ptr, bytes); 673 ttm_bo_kunmap(&map); 674 675 page++; 676 buf += bytes; 677 bytes_left -= bytes; 678 offset = 0; 679 } while (bytes_left); 680 681 return len; 682 } 683 684 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, 685 void *buf, int len, int write) 686 { 687 struct ttm_buffer_object *bo = vma->vm_private_data; 688 unsigned long offset = (addr) - vma->vm_start + 689 ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node)) 690 << PAGE_SHIFT); 691 int ret; 692 693 if (len < 1 || (offset + len) > bo->base.size) 694 return -EIO; 695 696 ret = ttm_bo_reserve(bo, true, false, NULL); 697 if (ret) 698 return ret; 699 700 switch (bo->resource->mem_type) { 701 case TTM_PL_SYSTEM: 702 fallthrough; 703 case TTM_PL_TT: 704 ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write); 705 break; 706 default: 707 if (bo->bdev->funcs->access_memory) 708 ret = bo->bdev->funcs->access_memory( 709 bo, offset, buf, len, write); 710 else 711 ret = -EIO; 712 } 713 714 ttm_bo_unreserve(bo); 715 716 return ret; 717 } 718 EXPORT_SYMBOL(ttm_bo_vm_access); 719 720 static const struct vm_operations_struct ttm_bo_vm_ops = { 721 .fault = ttm_bo_vm_fault, 722 .open = ttm_bo_vm_open, 723 .close = ttm_bo_vm_close, 724 .access = ttm_bo_vm_access, 725 }; 726 #endif 727 728 void 729 ttm_bo_vm_reference(struct uvm_object *uobj) 730 { 731 struct ttm_buffer_object *bo = 732 (struct ttm_buffer_object *)uobj; 733 734 ttm_bo_get(bo); 735 } 736 737 void 738 ttm_bo_vm_detach(struct uvm_object *uobj) 739 { 740 struct ttm_buffer_object *bo = (struct ttm_buffer_object *)uobj; 741 742 ttm_bo_put(bo); 743 } 744 745 const struct uvm_pagerops ttm_bo_vm_ops = { 746 .pgo_fault = ttm_bo_vm_fault, 747 .pgo_reference = ttm_bo_vm_reference, 748 .pgo_detach = ttm_bo_vm_detach 749 }; 750 751 #ifdef __linux__ 752 /** 753 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object. 754 * 755 * @vma: vma as input from the fbdev mmap method. 756 * @bo: The bo backing the address space. 757 * 758 * Maps a buffer object. 759 */ 760 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 761 { 762 /* Enforce no COW since would have really strange behavior with it. */ 763 if (is_cow_mapping(vma->vm_flags)) 764 return -EINVAL; 765 766 ttm_bo_get(bo); 767 768 /* 769 * Drivers may want to override the vm_ops field. Otherwise we 770 * use TTM's default callbacks. 771 */ 772 if (!vma->vm_ops) 773 vma->vm_ops = &ttm_bo_vm_ops; 774 775 /* 776 * Note: We're transferring the bo reference to 777 * vma->vm_private_data here. 778 */ 779 780 vma->vm_private_data = bo; 781 782 vm_flags_set(vma, VM_PFNMAP | VM_IO | VM_DONTEXPAND | VM_DONTDUMP); 783 return 0; 784 } 785 EXPORT_SYMBOL(ttm_bo_mmap_obj); 786 #else /* !__linux__ */ 787 int ttm_bo_mmap_obj(struct ttm_buffer_object *bo) 788 { 789 /* Enforce no COW since would have really strange behavior with it. */ 790 #ifdef notyet 791 if (UVM_ET_ISCOPYONWRITE(entry)) 792 return -EINVAL; 793 #endif 794 795 ttm_bo_get(bo); 796 797 /* 798 * Drivers may want to override the vm_ops field. Otherwise we 799 * use TTM's default callbacks. 800 */ 801 if (bo->base.uobj.pgops == NULL) 802 uvm_obj_init(&bo->base.uobj, &ttm_bo_vm_ops, 1); 803 804 /* 805 * Note: We're transferring the bo reference to 806 * vma->vm_private_data here. 807 */ 808 809 #ifdef notyet 810 vma->vm_private_data = bo; 811 812 vma->vm_flags |= VM_PFNMAP; 813 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; 814 #endif 815 return 0; 816 } 817 #endif /* !__linux__ */ 818