1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright © 2014-2016 Intel Corporation 5 */ 6 7 #include <drm/drm_cache.h> 8 9 #include "i915_drv.h" 10 #include "i915_gem_object.h" 11 #include "i915_scatterlist.h" 12 #include "i915_gem_lmem.h" 13 #include "i915_gem_mman.h" 14 15 #include "gt/intel_gt.h" 16 17 void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, 18 struct sg_table *pages, 19 unsigned int sg_page_sizes) 20 { 21 struct drm_i915_private *i915 = to_i915(obj->base.dev); 22 unsigned long supported = INTEL_INFO(i915)->page_sizes; 23 bool shrinkable; 24 int i; 25 26 assert_object_held_shared(obj); 27 28 if (i915_gem_object_is_volatile(obj)) 29 obj->mm.madv = I915_MADV_DONTNEED; 30 31 /* Make the pages coherent with the GPU (flushing any swapin). */ 32 if (obj->cache_dirty) { 33 WARN_ON_ONCE(IS_DGFX(i915)); 34 obj->write_domain = 0; 35 if (i915_gem_object_has_struct_page(obj)) 36 drm_clflush_sg(pages); 37 obj->cache_dirty = false; 38 } 39 40 obj->mm.get_page.sg_pos = pages->sgl; 41 obj->mm.get_page.sg_idx = 0; 42 obj->mm.get_dma_page.sg_pos = pages->sgl; 43 obj->mm.get_dma_page.sg_idx = 0; 44 45 obj->mm.pages = pages; 46 47 GEM_BUG_ON(!sg_page_sizes); 48 obj->mm.page_sizes.phys = sg_page_sizes; 49 50 /* 51 * Calculate the supported page-sizes which fit into the given 52 * sg_page_sizes. This will give us the page-sizes which we may be able 53 * to use opportunistically when later inserting into the GTT. For 54 * example if phys=2G, then in theory we should be able to use 1G, 2M, 55 * 64K or 4K pages, although in practice this will depend on a number of 56 * other factors. 57 */ 58 obj->mm.page_sizes.sg = 0; 59 for_each_set_bit(i, &supported, ilog2(I915_GTT_MAX_PAGE_SIZE) + 1) { 60 if (obj->mm.page_sizes.phys & ~0u << i) 61 obj->mm.page_sizes.sg |= BIT(i); 62 } 63 GEM_BUG_ON(!HAS_PAGE_SIZES(i915, obj->mm.page_sizes.sg)); 64 65 shrinkable = i915_gem_object_is_shrinkable(obj); 66 67 if (i915_gem_object_is_tiled(obj) && 68 i915->quirks & QUIRK_PIN_SWIZZLED_PAGES) { 69 GEM_BUG_ON(i915_gem_object_has_tiling_quirk(obj)); 70 i915_gem_object_set_tiling_quirk(obj); 71 GEM_BUG_ON(!list_empty(&obj->mm.link)); 72 atomic_inc(&obj->mm.shrink_pin); 73 shrinkable = false; 74 } 75 76 if (shrinkable && !i915_gem_object_has_self_managed_shrink_list(obj)) { 77 struct list_head *list; 78 unsigned long flags; 79 80 assert_object_held(obj); 81 spin_lock_irqsave(&i915->mm.obj_lock, flags); 82 83 i915->mm.shrink_count++; 84 i915->mm.shrink_memory += obj->base.size; 85 86 if (obj->mm.madv != I915_MADV_WILLNEED) 87 list = &i915->mm.purge_list; 88 else 89 list = &i915->mm.shrink_list; 90 list_add_tail(&obj->mm.link, list); 91 92 atomic_set(&obj->mm.shrink_pin, 0); 93 spin_unlock_irqrestore(&i915->mm.obj_lock, flags); 94 } 95 } 96 97 int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj) 98 { 99 struct drm_i915_private *i915 = to_i915(obj->base.dev); 100 int err; 101 102 assert_object_held_shared(obj); 103 104 if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) { 105 drm_dbg(&i915->drm, 106 "Attempting to obtain a purgeable object\n"); 107 return -EFAULT; 108 } 109 110 err = obj->ops->get_pages(obj); 111 GEM_BUG_ON(!err && !i915_gem_object_has_pages(obj)); 112 113 return err; 114 } 115 116 /* Ensure that the associated pages are gathered from the backing storage 117 * and pinned into our object. i915_gem_object_pin_pages() may be called 118 * multiple times before they are released by a single call to 119 * i915_gem_object_unpin_pages() - once the pages are no longer referenced 120 * either as a result of memory pressure (reaping pages under the shrinker) 121 * or as the object is itself released. 122 */ 123 int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj) 124 { 125 int err; 126 127 assert_object_held(obj); 128 129 assert_object_held_shared(obj); 130 131 if (unlikely(!i915_gem_object_has_pages(obj))) { 132 GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj)); 133 134 err = ____i915_gem_object_get_pages(obj); 135 if (err) 136 return err; 137 138 smp_mb__before_atomic(); 139 } 140 atomic_inc(&obj->mm.pages_pin_count); 141 142 return 0; 143 } 144 145 int i915_gem_object_pin_pages_unlocked(struct drm_i915_gem_object *obj) 146 { 147 struct i915_gem_ww_ctx ww; 148 int err; 149 150 i915_gem_ww_ctx_init(&ww, true); 151 retry: 152 err = i915_gem_object_lock(obj, &ww); 153 if (!err) 154 err = i915_gem_object_pin_pages(obj); 155 156 if (err == -EDEADLK) { 157 err = i915_gem_ww_ctx_backoff(&ww); 158 if (!err) 159 goto retry; 160 } 161 i915_gem_ww_ctx_fini(&ww); 162 return err; 163 } 164 165 /* Immediately discard the backing storage */ 166 int i915_gem_object_truncate(struct drm_i915_gem_object *obj) 167 { 168 if (obj->ops->truncate) 169 return obj->ops->truncate(obj); 170 171 return 0; 172 } 173 174 static void __i915_gem_object_reset_page_iter(struct drm_i915_gem_object *obj) 175 { 176 struct radix_tree_iter iter; 177 void __rcu **slot; 178 179 rcu_read_lock(); 180 radix_tree_for_each_slot(slot, &obj->mm.get_page.radix, &iter, 0) 181 radix_tree_delete(&obj->mm.get_page.radix, iter.index); 182 radix_tree_for_each_slot(slot, &obj->mm.get_dma_page.radix, &iter, 0) 183 radix_tree_delete(&obj->mm.get_dma_page.radix, iter.index); 184 rcu_read_unlock(); 185 } 186 187 static void unmap_object(struct drm_i915_gem_object *obj, void *ptr) 188 { 189 if (is_vmalloc_addr(ptr)) 190 vunmap(ptr); 191 } 192 193 struct sg_table * 194 __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj) 195 { 196 struct sg_table *pages; 197 198 assert_object_held_shared(obj); 199 200 pages = fetch_and_zero(&obj->mm.pages); 201 if (IS_ERR_OR_NULL(pages)) 202 return pages; 203 204 if (i915_gem_object_is_volatile(obj)) 205 obj->mm.madv = I915_MADV_WILLNEED; 206 207 if (!i915_gem_object_has_self_managed_shrink_list(obj)) 208 i915_gem_object_make_unshrinkable(obj); 209 210 if (obj->mm.mapping) { 211 unmap_object(obj, page_mask_bits(obj->mm.mapping)); 212 obj->mm.mapping = NULL; 213 } 214 215 __i915_gem_object_reset_page_iter(obj); 216 obj->mm.page_sizes.phys = obj->mm.page_sizes.sg = 0; 217 218 if (test_and_clear_bit(I915_BO_WAS_BOUND_BIT, &obj->flags)) { 219 struct drm_i915_private *i915 = to_i915(obj->base.dev); 220 intel_wakeref_t wakeref; 221 222 with_intel_runtime_pm_if_active(&i915->runtime_pm, wakeref) 223 intel_gt_invalidate_tlbs(to_gt(i915)); 224 } 225 226 return pages; 227 } 228 229 int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj) 230 { 231 struct sg_table *pages; 232 233 if (i915_gem_object_has_pinned_pages(obj)) 234 return -EBUSY; 235 236 /* May be called by shrinker from within get_pages() (on another bo) */ 237 assert_object_held_shared(obj); 238 239 i915_gem_object_release_mmap_offset(obj); 240 241 /* 242 * ->put_pages might need to allocate memory for the bit17 swizzle 243 * array, hence protect them from being reaped by removing them from gtt 244 * lists early. 245 */ 246 pages = __i915_gem_object_unset_pages(obj); 247 248 /* 249 * XXX Temporary hijinx to avoid updating all backends to handle 250 * NULL pages. In the future, when we have more asynchronous 251 * get_pages backends we should be better able to handle the 252 * cancellation of the async task in a more uniform manner. 253 */ 254 if (!IS_ERR_OR_NULL(pages)) 255 obj->ops->put_pages(obj, pages); 256 257 return 0; 258 } 259 260 /* The 'mapping' part of i915_gem_object_pin_map() below */ 261 static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj, 262 enum i915_map_type type) 263 { 264 unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i; 265 struct page *stack[32], **pages = stack, *page; 266 struct sgt_iter iter; 267 pgprot_t pgprot; 268 void *vaddr; 269 270 switch (type) { 271 default: 272 MISSING_CASE(type); 273 fallthrough; /* to use PAGE_KERNEL anyway */ 274 case I915_MAP_WB: 275 /* 276 * On 32b, highmem using a finite set of indirect PTE (i.e. 277 * vmap) to provide virtual mappings of the high pages. 278 * As these are finite, map_new_virtual() must wait for some 279 * other kmap() to finish when it runs out. If we map a large 280 * number of objects, there is no method for it to tell us 281 * to release the mappings, and we deadlock. 282 * 283 * However, if we make an explicit vmap of the page, that 284 * uses a larger vmalloc arena, and also has the ability 285 * to tell us to release unwanted mappings. Most importantly, 286 * it will fail and propagate an error instead of waiting 287 * forever. 288 * 289 * So if the page is beyond the 32b boundary, make an explicit 290 * vmap. 291 */ 292 if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl))) 293 return page_address(sg_page(obj->mm.pages->sgl)); 294 pgprot = PAGE_KERNEL; 295 break; 296 case I915_MAP_WC: 297 pgprot = pgprot_writecombine(PAGE_KERNEL_IO); 298 break; 299 } 300 301 if (n_pages > ARRAY_SIZE(stack)) { 302 /* Too big for stack -- allocate temporary array instead */ 303 pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL); 304 if (!pages) 305 return ERR_PTR(-ENOMEM); 306 } 307 308 i = 0; 309 for_each_sgt_page(page, iter, obj->mm.pages) 310 pages[i++] = page; 311 vaddr = vmap(pages, n_pages, 0, pgprot); 312 if (pages != stack) 313 kvfree(pages); 314 315 return vaddr ?: ERR_PTR(-ENOMEM); 316 } 317 318 static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj, 319 enum i915_map_type type) 320 { 321 resource_size_t iomap = obj->mm.region->iomap.base - 322 obj->mm.region->region.start; 323 unsigned long n_pfn = obj->base.size >> PAGE_SHIFT; 324 unsigned long stack[32], *pfns = stack, i; 325 struct sgt_iter iter; 326 dma_addr_t addr; 327 void *vaddr; 328 329 GEM_BUG_ON(type != I915_MAP_WC); 330 331 if (n_pfn > ARRAY_SIZE(stack)) { 332 /* Too big for stack -- allocate temporary array instead */ 333 pfns = kvmalloc_array(n_pfn, sizeof(*pfns), GFP_KERNEL); 334 if (!pfns) 335 return ERR_PTR(-ENOMEM); 336 } 337 338 i = 0; 339 for_each_sgt_daddr(addr, iter, obj->mm.pages) 340 pfns[i++] = (iomap + addr) >> PAGE_SHIFT; 341 vaddr = vmap_pfn(pfns, n_pfn, pgprot_writecombine(PAGE_KERNEL_IO)); 342 if (pfns != stack) 343 kvfree(pfns); 344 345 return vaddr ?: ERR_PTR(-ENOMEM); 346 } 347 348 /* get, pin, and map the pages of the object into kernel space */ 349 void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, 350 enum i915_map_type type) 351 { 352 enum i915_map_type has_type; 353 bool pinned; 354 void *ptr; 355 int err; 356 357 if (!i915_gem_object_has_struct_page(obj) && 358 !i915_gem_object_has_iomem(obj)) 359 return ERR_PTR(-ENXIO); 360 361 if (WARN_ON_ONCE(obj->flags & I915_BO_ALLOC_GPU_ONLY)) 362 return ERR_PTR(-EINVAL); 363 364 assert_object_held(obj); 365 366 pinned = !(type & I915_MAP_OVERRIDE); 367 type &= ~I915_MAP_OVERRIDE; 368 369 if (!atomic_inc_not_zero(&obj->mm.pages_pin_count)) { 370 if (unlikely(!i915_gem_object_has_pages(obj))) { 371 GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj)); 372 373 err = ____i915_gem_object_get_pages(obj); 374 if (err) 375 return ERR_PTR(err); 376 377 smp_mb__before_atomic(); 378 } 379 atomic_inc(&obj->mm.pages_pin_count); 380 pinned = false; 381 } 382 GEM_BUG_ON(!i915_gem_object_has_pages(obj)); 383 384 /* 385 * For discrete our CPU mappings needs to be consistent in order to 386 * function correctly on !x86. When mapping things through TTM, we use 387 * the same rules to determine the caching type. 388 * 389 * The caching rules, starting from DG1: 390 * 391 * - If the object can be placed in device local-memory, then the 392 * pages should be allocated and mapped as write-combined only. 393 * 394 * - Everything else is always allocated and mapped as write-back, 395 * with the guarantee that everything is also coherent with the 396 * GPU. 397 * 398 * Internal users of lmem are already expected to get this right, so no 399 * fudging needed there. 400 */ 401 if (i915_gem_object_placement_possible(obj, INTEL_MEMORY_LOCAL)) { 402 if (type != I915_MAP_WC && !obj->mm.n_placements) { 403 ptr = ERR_PTR(-ENODEV); 404 goto err_unpin; 405 } 406 407 type = I915_MAP_WC; 408 } else if (IS_DGFX(to_i915(obj->base.dev))) { 409 type = I915_MAP_WB; 410 } 411 412 ptr = page_unpack_bits(obj->mm.mapping, &has_type); 413 if (ptr && has_type != type) { 414 if (pinned) { 415 ptr = ERR_PTR(-EBUSY); 416 goto err_unpin; 417 } 418 419 unmap_object(obj, ptr); 420 421 ptr = obj->mm.mapping = NULL; 422 } 423 424 if (!ptr) { 425 err = i915_gem_object_wait_moving_fence(obj, true); 426 if (err) { 427 ptr = ERR_PTR(err); 428 goto err_unpin; 429 } 430 431 if (GEM_WARN_ON(type == I915_MAP_WC && !pat_enabled())) 432 ptr = ERR_PTR(-ENODEV); 433 else if (i915_gem_object_has_struct_page(obj)) 434 ptr = i915_gem_object_map_page(obj, type); 435 else 436 ptr = i915_gem_object_map_pfn(obj, type); 437 if (IS_ERR(ptr)) 438 goto err_unpin; 439 440 obj->mm.mapping = page_pack_bits(ptr, type); 441 } 442 443 return ptr; 444 445 err_unpin: 446 atomic_dec(&obj->mm.pages_pin_count); 447 return ptr; 448 } 449 450 void *i915_gem_object_pin_map_unlocked(struct drm_i915_gem_object *obj, 451 enum i915_map_type type) 452 { 453 void *ret; 454 455 i915_gem_object_lock(obj, NULL); 456 ret = i915_gem_object_pin_map(obj, type); 457 i915_gem_object_unlock(obj); 458 459 return ret; 460 } 461 462 void __i915_gem_object_flush_map(struct drm_i915_gem_object *obj, 463 unsigned long offset, 464 unsigned long size) 465 { 466 enum i915_map_type has_type; 467 void *ptr; 468 469 GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj)); 470 GEM_BUG_ON(range_overflows_t(typeof(obj->base.size), 471 offset, size, obj->base.size)); 472 473 wmb(); /* let all previous writes be visible to coherent partners */ 474 obj->mm.dirty = true; 475 476 if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE) 477 return; 478 479 ptr = page_unpack_bits(obj->mm.mapping, &has_type); 480 if (has_type == I915_MAP_WC) 481 return; 482 483 drm_clflush_virt_range(ptr + offset, size); 484 if (size == obj->base.size) { 485 obj->write_domain &= ~I915_GEM_DOMAIN_CPU; 486 obj->cache_dirty = false; 487 } 488 } 489 490 void __i915_gem_object_release_map(struct drm_i915_gem_object *obj) 491 { 492 GEM_BUG_ON(!obj->mm.mapping); 493 494 /* 495 * We allow removing the mapping from underneath pinned pages! 496 * 497 * Furthermore, since this is an unsafe operation reserved only 498 * for construction time manipulation, we ignore locking prudence. 499 */ 500 unmap_object(obj, page_mask_bits(fetch_and_zero(&obj->mm.mapping))); 501 502 i915_gem_object_unpin_map(obj); 503 } 504 505 struct scatterlist * 506 __i915_gem_object_get_sg(struct drm_i915_gem_object *obj, 507 struct i915_gem_object_page_iter *iter, 508 unsigned int n, 509 unsigned int *offset, 510 bool dma) 511 { 512 struct scatterlist *sg; 513 unsigned int idx, count; 514 515 might_sleep(); 516 GEM_BUG_ON(n >= obj->base.size >> PAGE_SHIFT); 517 if (!i915_gem_object_has_pinned_pages(obj)) 518 assert_object_held(obj); 519 520 /* As we iterate forward through the sg, we record each entry in a 521 * radixtree for quick repeated (backwards) lookups. If we have seen 522 * this index previously, we will have an entry for it. 523 * 524 * Initial lookup is O(N), but this is amortized to O(1) for 525 * sequential page access (where each new request is consecutive 526 * to the previous one). Repeated lookups are O(lg(obj->base.size)), 527 * i.e. O(1) with a large constant! 528 */ 529 if (n < READ_ONCE(iter->sg_idx)) 530 goto lookup; 531 532 mutex_lock(&iter->lock); 533 534 /* We prefer to reuse the last sg so that repeated lookup of this 535 * (or the subsequent) sg are fast - comparing against the last 536 * sg is faster than going through the radixtree. 537 */ 538 539 sg = iter->sg_pos; 540 idx = iter->sg_idx; 541 count = dma ? __sg_dma_page_count(sg) : __sg_page_count(sg); 542 543 while (idx + count <= n) { 544 void *entry; 545 unsigned long i; 546 int ret; 547 548 /* If we cannot allocate and insert this entry, or the 549 * individual pages from this range, cancel updating the 550 * sg_idx so that on this lookup we are forced to linearly 551 * scan onwards, but on future lookups we will try the 552 * insertion again (in which case we need to be careful of 553 * the error return reporting that we have already inserted 554 * this index). 555 */ 556 ret = radix_tree_insert(&iter->radix, idx, sg); 557 if (ret && ret != -EEXIST) 558 goto scan; 559 560 entry = xa_mk_value(idx); 561 for (i = 1; i < count; i++) { 562 ret = radix_tree_insert(&iter->radix, idx + i, entry); 563 if (ret && ret != -EEXIST) 564 goto scan; 565 } 566 567 idx += count; 568 sg = ____sg_next(sg); 569 count = dma ? __sg_dma_page_count(sg) : __sg_page_count(sg); 570 } 571 572 scan: 573 iter->sg_pos = sg; 574 iter->sg_idx = idx; 575 576 mutex_unlock(&iter->lock); 577 578 if (unlikely(n < idx)) /* insertion completed by another thread */ 579 goto lookup; 580 581 /* In case we failed to insert the entry into the radixtree, we need 582 * to look beyond the current sg. 583 */ 584 while (idx + count <= n) { 585 idx += count; 586 sg = ____sg_next(sg); 587 count = dma ? __sg_dma_page_count(sg) : __sg_page_count(sg); 588 } 589 590 *offset = n - idx; 591 return sg; 592 593 lookup: 594 rcu_read_lock(); 595 596 sg = radix_tree_lookup(&iter->radix, n); 597 GEM_BUG_ON(!sg); 598 599 /* If this index is in the middle of multi-page sg entry, 600 * the radix tree will contain a value entry that points 601 * to the start of that range. We will return the pointer to 602 * the base page and the offset of this page within the 603 * sg entry's range. 604 */ 605 *offset = 0; 606 if (unlikely(xa_is_value(sg))) { 607 unsigned long base = xa_to_value(sg); 608 609 sg = radix_tree_lookup(&iter->radix, base); 610 GEM_BUG_ON(!sg); 611 612 *offset = n - base; 613 } 614 615 rcu_read_unlock(); 616 617 return sg; 618 } 619 620 struct page * 621 i915_gem_object_get_page(struct drm_i915_gem_object *obj, unsigned int n) 622 { 623 struct scatterlist *sg; 624 unsigned int offset; 625 626 GEM_BUG_ON(!i915_gem_object_has_struct_page(obj)); 627 628 sg = i915_gem_object_get_sg(obj, n, &offset); 629 return nth_page(sg_page(sg), offset); 630 } 631 632 /* Like i915_gem_object_get_page(), but mark the returned page dirty */ 633 struct page * 634 i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, 635 unsigned int n) 636 { 637 struct page *page; 638 639 page = i915_gem_object_get_page(obj, n); 640 if (!obj->mm.dirty) 641 set_page_dirty(page); 642 643 return page; 644 } 645 646 dma_addr_t 647 i915_gem_object_get_dma_address_len(struct drm_i915_gem_object *obj, 648 unsigned long n, 649 unsigned int *len) 650 { 651 struct scatterlist *sg; 652 unsigned int offset; 653 654 sg = i915_gem_object_get_sg_dma(obj, n, &offset); 655 656 if (len) 657 *len = sg_dma_len(sg) - (offset << PAGE_SHIFT); 658 659 return sg_dma_address(sg) + (offset << PAGE_SHIFT); 660 } 661 662 dma_addr_t 663 i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj, 664 unsigned long n) 665 { 666 return i915_gem_object_get_dma_address_len(obj, n, NULL); 667 } 668