1 // SPDX-License-Identifier: GPL-2.0-or-later
3 #include <drm/drm_gem_vram_helper.h>
4 #include <drm/drm_device.h>
5 #include <drm/drm_mode.h>
6 #include <drm/drm_prime.h>
7 #include <drm/drm_vram_mm_helper.h>
8 #include <drm/ttm/ttm_page_alloc.h>
13 * This library provides a GEM buffer object that is backed by video RAM
14 * (VRAM). It can be used for framebuffer devices with dedicated memory.
18 * Buffer-objects helpers
21 static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
23 /* We got here via ttm_bo_put(), which means that the
24 * TTM buffer object in 'bo' has already been cleaned
25 * up; only release the GEM object.
27 drm_gem_object_release(&gbo->gem);
30 static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
32 drm_gem_vram_cleanup(gbo);
36 static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
38 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
40 drm_gem_vram_destroy(gbo);
43 static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
44 unsigned long pl_flag)
49 gbo->placement.placement = gbo->placements;
50 gbo->placement.busy_placement = gbo->placements;
52 if (pl_flag & TTM_PL_FLAG_VRAM)
53 gbo->placements[c++].flags = TTM_PL_FLAG_WC |
54 TTM_PL_FLAG_UNCACHED |
57 if (pl_flag & TTM_PL_FLAG_SYSTEM)
58 gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
62 gbo->placements[c++].flags = TTM_PL_MASK_CACHING |
65 gbo->placement.num_placement = c;
66 gbo->placement.num_busy_placement = c;
68 for (i = 0; i < c; ++i) {
69 gbo->placements[i].fpfn = 0;
70 gbo->placements[i].lpfn = 0;
74 static int drm_gem_vram_init(struct drm_device *dev,
75 struct ttm_bo_device *bdev,
76 struct drm_gem_vram_object *gbo,
77 size_t size, unsigned long pg_align,
83 ret = drm_gem_object_init(dev, &gbo->gem, size);
87 acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo));
90 drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
92 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
93 &gbo->placement, pg_align, interruptible, acc_size,
94 NULL, NULL, ttm_buffer_object_destroy);
96 goto err_drm_gem_object_release;
100 err_drm_gem_object_release:
101 drm_gem_object_release(&gbo->gem);
106 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
107 * @dev: the DRM device
108 * @bdev: the TTM BO device backing the object
109 * @size: the buffer size in bytes
110 * @pg_align: the buffer's alignment in multiples of the page size
111 * @interruptible: sleep interruptible if waiting for memory
114 * A new instance of &struct drm_gem_vram_object on success, or
115 * an ERR_PTR()-encoded error code otherwise.
117 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
118 struct ttm_bo_device *bdev,
120 unsigned long pg_align,
123 struct drm_gem_vram_object *gbo;
126 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
128 return ERR_PTR(-ENOMEM);
130 ret = drm_gem_vram_init(dev, bdev, gbo, size, pg_align, interruptible);
140 EXPORT_SYMBOL(drm_gem_vram_create);
143 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
144 * @gbo: the GEM VRAM object
146 * See ttm_bo_put() for more information.
148 void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
150 ttm_bo_put(&gbo->bo);
152 EXPORT_SYMBOL(drm_gem_vram_put);
155 * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
156 * @gbo: the GEM VRAM object
158 * See drm_vma_node_offset_addr() for more information.
161 * The buffer object's offset for userspace mappings on success, or
162 * 0 if no offset is allocated.
164 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
166 return drm_vma_node_offset_addr(&gbo->bo.vma_node);
168 EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
171 * drm_gem_vram_offset() - \
172 Returns a GEM VRAM object's offset in video memory
173 * @gbo: the GEM VRAM object
175 * This function returns the buffer object's offset in the device's video
176 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
179 * The buffer object's offset in video memory on success, or
180 * a negative errno code otherwise.
182 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
184 if (WARN_ON_ONCE(!gbo->pin_count))
186 return gbo->bo.offset;
188 EXPORT_SYMBOL(drm_gem_vram_offset);
191 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
192 * @gbo: the GEM VRAM object
193 * @pl_flag: a bitmask of possible memory regions
195 * Pinning a buffer object ensures that it is not evicted from
196 * a memory region. A pinned buffer object has to be unpinned before
197 * it can be pinned to another region. If the pl_flag argument is 0,
198 * the buffer is pinned at its current location (video RAM or system
203 * a negative error code otherwise.
205 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
208 struct ttm_operation_ctx ctx = { false, false };
210 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
218 drm_gem_vram_placement(gbo, pl_flag);
220 for (i = 0; i < gbo->placement.num_placement; ++i)
221 gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT;
223 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
225 goto err_ttm_bo_unreserve;
229 ttm_bo_unreserve(&gbo->bo);
233 err_ttm_bo_unreserve:
234 ttm_bo_unreserve(&gbo->bo);
237 EXPORT_SYMBOL(drm_gem_vram_pin);
240 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
241 * @gbo: the GEM VRAM object
245 * a negative error code otherwise.
247 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
250 struct ttm_operation_ctx ctx = { false, false };
252 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
256 if (WARN_ON_ONCE(!gbo->pin_count))
263 for (i = 0; i < gbo->placement.num_placement ; ++i)
264 gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT;
266 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
268 goto err_ttm_bo_unreserve;
271 ttm_bo_unreserve(&gbo->bo);
275 err_ttm_bo_unreserve:
276 ttm_bo_unreserve(&gbo->bo);
279 EXPORT_SYMBOL(drm_gem_vram_unpin);
282 * drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space
283 * @gbo: the GEM VRAM object
284 * @map: establish a mapping if necessary
285 * @is_iomem: returns true if the mapped memory is I/O memory, or false \
286 otherwise; can be NULL
288 * This function maps the buffer object into the kernel's address space
289 * or returns the current mapping. If the parameter map is false, the
290 * function only queries the current mapping, but does not establish a
294 * The buffers virtual address if mapped, or
295 * NULL if not mapped, or
296 * an ERR_PTR()-encoded error code otherwise.
298 void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
302 struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
304 if (kmap->virtual || !map)
307 ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
313 return kmap->virtual;
314 if (!kmap->virtual) {
318 return ttm_kmap_obj_virtual(kmap, is_iomem);
320 EXPORT_SYMBOL(drm_gem_vram_kmap);
323 * drm_gem_vram_kunmap() - Unmaps a GEM VRAM object
324 * @gbo: the GEM VRAM object
326 void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo)
328 struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
334 kmap->virtual = NULL;
336 EXPORT_SYMBOL(drm_gem_vram_kunmap);
339 * drm_gem_vram_fill_create_dumb() - \
340 Helper for implementing &struct drm_driver.dumb_create
341 * @file: the DRM file
342 * @dev: the DRM device
343 * @bdev: the TTM BO device managing the buffer object
344 * @pg_align: the buffer's alignment in multiples of the page size
345 * @interruptible: sleep interruptible if waiting for memory
346 * @args: the arguments as provided to \
347 &struct drm_driver.dumb_create
349 * This helper function fills &struct drm_mode_create_dumb, which is used
350 * by &struct drm_driver.dumb_create. Implementations of this interface
351 * should forwards their arguments to this helper, plus the driver-specific
356 * a negative error code otherwise.
358 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
359 struct drm_device *dev,
360 struct ttm_bo_device *bdev,
361 unsigned long pg_align,
363 struct drm_mode_create_dumb *args)
366 struct drm_gem_vram_object *gbo;
370 pitch = args->width * ((args->bpp + 7) / 8);
371 size = pitch * args->height;
373 size = roundup(size, PAGE_SIZE);
377 gbo = drm_gem_vram_create(dev, bdev, size, pg_align, interruptible);
381 ret = drm_gem_handle_create(file, &gbo->gem, &handle);
383 goto err_drm_gem_object_put_unlocked;
385 drm_gem_object_put_unlocked(&gbo->gem);
389 args->handle = handle;
393 err_drm_gem_object_put_unlocked:
394 drm_gem_object_put_unlocked(&gbo->gem);
397 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
400 * Helpers for struct ttm_bo_driver
403 static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
405 return (bo->destroy == ttm_buffer_object_destroy);
409 * drm_gem_vram_bo_driver_evict_flags() - \
410 Implements &struct ttm_bo_driver.evict_flags
411 * @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo
412 * @pl: TTM placement information.
414 void drm_gem_vram_bo_driver_evict_flags(struct ttm_buffer_object *bo,
415 struct ttm_placement *pl)
417 struct drm_gem_vram_object *gbo;
419 /* TTM may pass BOs that are not GEM VRAM BOs. */
420 if (!drm_is_gem_vram(bo))
423 gbo = drm_gem_vram_of_bo(bo);
424 drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM);
425 *pl = gbo->placement;
427 EXPORT_SYMBOL(drm_gem_vram_bo_driver_evict_flags);
430 * drm_gem_vram_bo_driver_verify_access() - \
431 Implements &struct ttm_bo_driver.verify_access
432 * @bo: TTM buffer object. Refers to &struct drm_gem_vram_object.bo
433 * @filp: File pointer.
437 * a negative errno code otherwise.
439 int drm_gem_vram_bo_driver_verify_access(struct ttm_buffer_object *bo,
442 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
444 return drm_vma_node_verify_access(&gbo->gem.vma_node,
447 EXPORT_SYMBOL(drm_gem_vram_bo_driver_verify_access);
450 * drm_gem_vram_mm_funcs - Functions for &struct drm_vram_mm
452 * Most users of @struct drm_gem_vram_object will also use
453 * @struct drm_vram_mm. This instance of &struct drm_vram_mm_funcs
454 * can be used to connect both.
456 const struct drm_vram_mm_funcs drm_gem_vram_mm_funcs = {
457 .evict_flags = drm_gem_vram_bo_driver_evict_flags,
458 .verify_access = drm_gem_vram_bo_driver_verify_access
460 EXPORT_SYMBOL(drm_gem_vram_mm_funcs);
463 * Helpers for struct drm_driver
467 * drm_gem_vram_driver_gem_free_object_unlocked() - \
468 Implements &struct drm_driver.gem_free_object_unlocked
469 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
471 void drm_gem_vram_driver_gem_free_object_unlocked(struct drm_gem_object *gem)
473 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
475 drm_gem_vram_put(gbo);
477 EXPORT_SYMBOL(drm_gem_vram_driver_gem_free_object_unlocked);
480 * drm_gem_vram_driver_create_dumb() - \
481 Implements &struct drm_driver.dumb_create
482 * @file: the DRM file
483 * @dev: the DRM device
484 * @args: the arguments as provided to \
485 &struct drm_driver.dumb_create
487 * This function requires the driver to use @drm_device.vram_mm for its
488 * instance of VRAM MM.
492 * a negative error code otherwise.
494 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
495 struct drm_device *dev,
496 struct drm_mode_create_dumb *args)
498 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
501 return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev, 0,
504 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
507 * drm_gem_vram_driver_dumb_mmap_offset() - \
508 Implements &struct drm_driver.dumb_mmap_offset
509 * @file: DRM file pointer.
511 * @handle: GEM handle
512 * @offset: Returns the mapping's memory offset on success
516 * a negative errno code otherwise.
518 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
519 struct drm_device *dev,
520 uint32_t handle, uint64_t *offset)
522 struct drm_gem_object *gem;
523 struct drm_gem_vram_object *gbo;
525 gem = drm_gem_object_lookup(file, handle);
529 gbo = drm_gem_vram_of_gem(gem);
530 *offset = drm_gem_vram_mmap_offset(gbo);
532 drm_gem_object_put_unlocked(gem);
536 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
539 * PRIME helpers for struct drm_driver
543 * drm_gem_vram_driver_gem_prime_pin() - \
544 Implements &struct drm_driver.gem_prime_pin
545 * @gem: The GEM object to pin
549 * a negative errno code otherwise.
551 int drm_gem_vram_driver_gem_prime_pin(struct drm_gem_object *gem)
553 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
555 /* Fbdev console emulation is the use case of these PRIME
556 * helpers. This may involve updating a hardware buffer from
557 * a shadow FB. We pin the buffer to it's current location
558 * (either video RAM or system memory) to prevent it from
559 * being relocated during the update operation. If you require
560 * the buffer to be pinned to VRAM, implement a callback that
561 * sets the flags accordingly.
563 return drm_gem_vram_pin(gbo, 0);
565 EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_pin);
568 * drm_gem_vram_driver_gem_prime_unpin() - \
569 Implements &struct drm_driver.gem_prime_unpin
570 * @gem: The GEM object to unpin
572 void drm_gem_vram_driver_gem_prime_unpin(struct drm_gem_object *gem)
574 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
576 drm_gem_vram_unpin(gbo);
578 EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_unpin);
581 * drm_gem_vram_driver_gem_prime_vmap() - \
582 Implements &struct drm_driver.gem_prime_vmap
583 * @gem: The GEM object to map
586 * The buffers virtual address on success, or
589 void *drm_gem_vram_driver_gem_prime_vmap(struct drm_gem_object *gem)
591 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
595 ret = drm_gem_vram_pin(gbo, 0);
598 base = drm_gem_vram_kmap(gbo, true, NULL);
600 drm_gem_vram_unpin(gbo);
605 EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_vmap);
608 * drm_gem_vram_driver_gem_prime_vunmap() - \
609 Implements &struct drm_driver.gem_prime_vunmap
610 * @gem: The GEM object to unmap
611 * @vaddr: The mapping's base address
613 void drm_gem_vram_driver_gem_prime_vunmap(struct drm_gem_object *gem,
616 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
618 drm_gem_vram_kunmap(gbo);
619 drm_gem_vram_unpin(gbo);
621 EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_vunmap);
624 * drm_gem_vram_driver_gem_prime_mmap() - \
625 Implements &struct drm_driver.gem_prime_mmap
626 * @gem: The GEM object to map
627 * @vma: The VMA describing the mapping
631 * a negative errno code otherwise.
633 int drm_gem_vram_driver_gem_prime_mmap(struct drm_gem_object *gem,
634 struct vm_area_struct *vma)
636 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
638 gbo->gem.vma_node.vm_node.start = gbo->bo.vma_node.vm_node.start;
639 return drm_gem_prime_mmap(gem, vma);
641 EXPORT_SYMBOL(drm_gem_vram_driver_gem_prime_mmap);