1 // SPDX-License-Identifier: GPL-2.0-or-later
3 #include <linux/dma-buf-map.h>
4 #include <linux/module.h>
6 #include <drm/drm_debugfs.h>
7 #include <drm/drm_device.h>
8 #include <drm/drm_drv.h>
9 #include <drm/drm_file.h>
10 #include <drm/drm_framebuffer.h>
11 #include <drm/drm_gem_framebuffer_helper.h>
12 #include <drm/drm_gem_ttm_helper.h>
13 #include <drm/drm_gem_vram_helper.h>
14 #include <drm/drm_managed.h>
15 #include <drm/drm_mode.h>
16 #include <drm/drm_plane.h>
17 #include <drm/drm_prime.h>
18 #include <drm/drm_simple_kms_helper.h>
20 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
25 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM
26 * buffer object that is backed by video RAM (VRAM). It can be used for
27 * framebuffer devices with dedicated memory.
29 * The data structure &struct drm_vram_mm and its helpers implement a memory
30 * manager for simple framebuffer devices with dedicated video memory. GEM
31 * VRAM buffer objects are either placed in the video memory or remain evicted
34 * With the GEM interface userspace applications create, manage and destroy
35 * graphics buffers, such as an on-screen framebuffer. GEM does not provide
36 * an implementation of these interfaces. It's up to the DRM driver to
37 * provide an implementation that suits the hardware. If the hardware device
38 * contains dedicated video memory, the DRM driver can use the VRAM helper
39 * library. Each active buffer object is stored in video RAM. Active
40 * buffer are used for drawing the current frame, typically something like
41 * the frame's scanout buffer or the cursor image. If there's no more space
42 * left in VRAM, inactive GEM objects can be moved to system memory.
44 * To initialize the VRAM helper library call drmm_vram_helper_alloc_mm().
45 * The function allocates and initializes an instance of &struct drm_vram_mm
46 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize
47 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize
48 * &struct file_operations; as illustrated below.
52 * struct file_operations fops ={
53 * .owner = THIS_MODULE,
54 * DRM_VRAM_MM_FILE_OPERATION
56 * struct drm_driver drv = {
57 * .driver_feature = DRM_ ... ,
62 * int init_drm_driver()
64 * struct drm_device *dev;
66 * unsigned long vram_size;
69 * // setup device, vram base and size
72 * ret = drmm_vram_helper_alloc_mm(dev, vram_base, vram_size);
78 * This creates an instance of &struct drm_vram_mm, exports DRM userspace
79 * interfaces for GEM buffer management and initializes file operations to
80 * allow for accessing created GEM buffers. With this setup, the DRM driver
81 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects
84 * You don't have to clean up the instance of VRAM MM.
85 * drmm_vram_helper_alloc_mm() is a managed interface that installs a
86 * clean-up handler to run during the DRM device's release.
88 * For drawing or scanout operations, rsp. buffer objects have to be pinned
89 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or
90 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system
91 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards.
93 * A buffer object that is pinned in video RAM has a fixed address within that
94 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically
95 * it's used to program the hardware's scanout engine for framebuffers, set
96 * the cursor overlay's image for a mouse cursor, or use it as input to the
97 * hardware's draing engine.
99 * To access a buffer object's memory from the DRM driver, call
100 * drm_gem_vram_vmap(). It maps the buffer into kernel address
101 * space and returns the memory address. Use drm_gem_vram_vunmap() to
102 * release the mapping.
106 * Buffer-objects helpers
109 static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
111 /* We got here via ttm_bo_put(), which means that the
112 * TTM buffer object in 'bo' has already been cleaned
113 * up; only release the GEM object.
116 WARN_ON(gbo->vmap_use_count);
117 WARN_ON(dma_buf_map_is_set(&gbo->map));
119 drm_gem_object_release(&gbo->bo.base);
122 static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
124 drm_gem_vram_cleanup(gbo);
128 static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
130 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
132 drm_gem_vram_destroy(gbo);
135 static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
136 unsigned long pl_flag)
138 u32 invariant_flags = 0;
142 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_TOPDOWN)
143 invariant_flags = TTM_PL_FLAG_TOPDOWN;
145 gbo->placement.placement = gbo->placements;
146 gbo->placement.busy_placement = gbo->placements;
148 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_VRAM) {
149 gbo->placements[c].mem_type = TTM_PL_VRAM;
150 gbo->placements[c++].flags = invariant_flags;
153 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_SYSTEM || !c) {
154 gbo->placements[c].mem_type = TTM_PL_SYSTEM;
155 gbo->placements[c++].flags = invariant_flags;
158 gbo->placement.num_placement = c;
159 gbo->placement.num_busy_placement = c;
161 for (i = 0; i < c; ++i) {
162 gbo->placements[i].fpfn = 0;
163 gbo->placements[i].lpfn = 0;
168 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
169 * @dev: the DRM device
170 * @size: the buffer size in bytes
171 * @pg_align: the buffer's alignment in multiples of the page size
173 * GEM objects are allocated by calling struct drm_driver.gem_create_object,
174 * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM
175 * object functions in struct drm_driver.gem_create_object. If no functions
176 * are set, the new GEM object will use the default functions from GEM VRAM
180 * A new instance of &struct drm_gem_vram_object on success, or
181 * an ERR_PTR()-encoded error code otherwise.
183 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
185 unsigned long pg_align)
187 struct drm_gem_vram_object *gbo;
188 struct drm_gem_object *gem;
189 struct drm_vram_mm *vmm = dev->vram_mm;
190 struct ttm_bo_device *bdev;
194 if (WARN_ONCE(!vmm, "VRAM MM not initialized"))
195 return ERR_PTR(-EINVAL);
197 if (dev->driver->gem_create_object) {
198 gem = dev->driver->gem_create_object(dev, size);
200 return ERR_PTR(-ENOMEM);
201 gbo = drm_gem_vram_of_gem(gem);
203 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
205 return ERR_PTR(-ENOMEM);
210 gem->funcs = &drm_gem_vram_object_funcs;
212 ret = drm_gem_object_init(dev, gem, size);
219 acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo));
222 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
225 * A failing ttm_bo_init will call ttm_buffer_object_destroy
226 * to release gbo->bo.base and kfree gbo.
228 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
229 &gbo->placement, pg_align, false, acc_size,
230 NULL, NULL, ttm_buffer_object_destroy);
236 EXPORT_SYMBOL(drm_gem_vram_create);
239 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
240 * @gbo: the GEM VRAM object
242 * See ttm_bo_put() for more information.
244 void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
246 ttm_bo_put(&gbo->bo);
248 EXPORT_SYMBOL(drm_gem_vram_put);
251 * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
252 * @gbo: the GEM VRAM object
254 * See drm_vma_node_offset_addr() for more information.
257 * The buffer object's offset for userspace mappings on success, or
258 * 0 if no offset is allocated.
260 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
262 return drm_vma_node_offset_addr(&gbo->bo.base.vma_node);
264 EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
266 static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
268 /* Keep TTM behavior for now, remove when drivers are audited */
269 if (WARN_ON_ONCE(!gbo->bo.mem.mm_node))
272 return gbo->bo.mem.start;
276 * drm_gem_vram_offset() - \
277 Returns a GEM VRAM object's offset in video memory
278 * @gbo: the GEM VRAM object
280 * This function returns the buffer object's offset in the device's video
281 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
284 * The buffer object's offset in video memory on success, or
285 * a negative errno code otherwise.
287 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
289 if (WARN_ON_ONCE(!gbo->bo.pin_count))
291 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
293 EXPORT_SYMBOL(drm_gem_vram_offset);
295 static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo,
296 unsigned long pl_flag)
298 struct ttm_operation_ctx ctx = { false, false };
301 if (gbo->bo.pin_count)
305 drm_gem_vram_placement(gbo, pl_flag);
307 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
312 ttm_bo_pin(&gbo->bo);
318 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
319 * @gbo: the GEM VRAM object
320 * @pl_flag: a bitmask of possible memory regions
322 * Pinning a buffer object ensures that it is not evicted from
323 * a memory region. A pinned buffer object has to be unpinned before
324 * it can be pinned to another region. If the pl_flag argument is 0,
325 * the buffer is pinned at its current location (video RAM or system
328 * Small buffer objects, such as cursor images, can lead to memory
329 * fragmentation if they are pinned in the middle of video RAM. This
330 * is especially a problem on devices with only a small amount of
331 * video RAM. Fragmentation can prevent the primary framebuffer from
332 * fitting in, even though there's enough memory overall. The modifier
333 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned
334 * at the high end of the memory region to avoid fragmentation.
338 * a negative error code otherwise.
340 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
344 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
347 ret = drm_gem_vram_pin_locked(gbo, pl_flag);
348 ttm_bo_unreserve(&gbo->bo);
352 EXPORT_SYMBOL(drm_gem_vram_pin);
354 static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)
356 ttm_bo_unpin(&gbo->bo);
360 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
361 * @gbo: the GEM VRAM object
365 * a negative error code otherwise.
367 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
371 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
375 drm_gem_vram_unpin_locked(gbo);
376 ttm_bo_unreserve(&gbo->bo);
380 EXPORT_SYMBOL(drm_gem_vram_unpin);
382 static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
383 struct dma_buf_map *map)
387 if (gbo->vmap_use_count > 0)
391 * VRAM helpers unmap the BO only on demand. So the previous
392 * page mapping might still be around. Only vmap if the there's
393 * no mapping present.
395 if (dma_buf_map_is_null(&gbo->map)) {
396 ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
402 ++gbo->vmap_use_count;
408 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
409 struct dma_buf_map *map)
411 struct drm_device *dev = gbo->bo.base.dev;
413 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
416 if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
417 return; /* BUG: map not mapped from this BO */
419 if (--gbo->vmap_use_count > 0)
423 * Permanently mapping and unmapping buffers adds overhead from
424 * updating the page tables and creates debugging output. Therefore,
425 * we delay the actual unmap operation until the BO gets evicted
426 * from memory. See drm_gem_vram_bo_driver_move_notify().
431 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
433 * @gbo: The GEM VRAM object to map
434 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
437 * The vmap function pins a GEM VRAM object to its current location, either
438 * system or video memory, and maps its buffer into kernel address space.
439 * As pinned object cannot be relocated, you should avoid pinning objects
440 * permanently. Call drm_gem_vram_vunmap() with the returned address to
441 * unmap and unpin the GEM VRAM object.
444 * 0 on success, or a negative error code otherwise.
446 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
450 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
454 ret = drm_gem_vram_pin_locked(gbo, 0);
456 goto err_ttm_bo_unreserve;
457 ret = drm_gem_vram_kmap_locked(gbo, map);
459 goto err_drm_gem_vram_unpin_locked;
461 ttm_bo_unreserve(&gbo->bo);
465 err_drm_gem_vram_unpin_locked:
466 drm_gem_vram_unpin_locked(gbo);
467 err_ttm_bo_unreserve:
468 ttm_bo_unreserve(&gbo->bo);
471 EXPORT_SYMBOL(drm_gem_vram_vmap);
474 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
475 * @gbo: The GEM VRAM object to unmap
476 * @map: Kernel virtual address where the VRAM GEM object was mapped
478 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
479 * the documentation for drm_gem_vram_vmap() for more information.
481 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
485 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
486 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
489 drm_gem_vram_kunmap_locked(gbo, map);
490 drm_gem_vram_unpin_locked(gbo);
492 ttm_bo_unreserve(&gbo->bo);
494 EXPORT_SYMBOL(drm_gem_vram_vunmap);
497 * drm_gem_vram_fill_create_dumb() - \
498 Helper for implementing &struct drm_driver.dumb_create
499 * @file: the DRM file
500 * @dev: the DRM device
501 * @pg_align: the buffer's alignment in multiples of the page size
502 * @pitch_align: the scanline's alignment in powers of 2
503 * @args: the arguments as provided to \
504 &struct drm_driver.dumb_create
506 * This helper function fills &struct drm_mode_create_dumb, which is used
507 * by &struct drm_driver.dumb_create. Implementations of this interface
508 * should forwards their arguments to this helper, plus the driver-specific
513 * a negative error code otherwise.
515 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
516 struct drm_device *dev,
517 unsigned long pg_align,
518 unsigned long pitch_align,
519 struct drm_mode_create_dumb *args)
522 struct drm_gem_vram_object *gbo;
526 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
528 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
530 pitch = ALIGN(pitch, pitch_align);
532 size = pitch * args->height;
534 size = roundup(size, PAGE_SIZE);
538 gbo = drm_gem_vram_create(dev, size, pg_align);
542 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
544 goto err_drm_gem_object_put;
546 drm_gem_object_put(&gbo->bo.base);
550 args->handle = handle;
554 err_drm_gem_object_put:
555 drm_gem_object_put(&gbo->bo.base);
558 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
561 * Helpers for struct ttm_bo_driver
564 static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
566 return (bo->destroy == ttm_buffer_object_destroy);
569 static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
570 struct ttm_placement *pl)
572 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
573 *pl = gbo->placement;
576 static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo,
578 struct ttm_resource *new_mem)
580 struct ttm_buffer_object *bo = &gbo->bo;
581 struct drm_device *dev = bo->base.dev;
583 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
586 ttm_bo_vunmap(bo, &gbo->map);
587 dma_buf_map_clear(&gbo->map); /* explicitly clear mapping for next vmap call */
590 static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
592 struct ttm_operation_ctx *ctx,
593 struct ttm_resource *new_mem)
597 drm_gem_vram_bo_driver_move_notify(gbo, evict, new_mem);
598 ret = ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem);
600 swap(*new_mem, gbo->bo.mem);
601 drm_gem_vram_bo_driver_move_notify(gbo, false, new_mem);
602 swap(*new_mem, gbo->bo.mem);
608 * Helpers for struct drm_gem_object_funcs
612 * drm_gem_vram_object_free() - \
613 Implements &struct drm_gem_object_funcs.free
614 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
616 static void drm_gem_vram_object_free(struct drm_gem_object *gem)
618 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
620 drm_gem_vram_put(gbo);
624 * Helpers for dump buffers
628 * drm_gem_vram_driver_dumb_create() - \
629 Implements &struct drm_driver.dumb_create
630 * @file: the DRM file
631 * @dev: the DRM device
632 * @args: the arguments as provided to \
633 &struct drm_driver.dumb_create
635 * This function requires the driver to use @drm_device.vram_mm for its
636 * instance of VRAM MM.
640 * a negative error code otherwise.
642 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
643 struct drm_device *dev,
644 struct drm_mode_create_dumb *args)
646 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
649 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
651 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
654 * drm_gem_vram_driver_dumb_mmap_offset() - \
655 Implements &struct drm_driver.dumb_mmap_offset
656 * @file: DRM file pointer.
658 * @handle: GEM handle
659 * @offset: Returns the mapping's memory offset on success
663 * a negative errno code otherwise.
665 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
666 struct drm_device *dev,
667 uint32_t handle, uint64_t *offset)
669 struct drm_gem_object *gem;
670 struct drm_gem_vram_object *gbo;
672 gem = drm_gem_object_lookup(file, handle);
676 gbo = drm_gem_vram_of_gem(gem);
677 *offset = drm_gem_vram_mmap_offset(gbo);
679 drm_gem_object_put(gem);
683 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
686 * Helpers for struct drm_plane_helper_funcs
690 * drm_gem_vram_plane_helper_prepare_fb() - \
691 * Implements &struct drm_plane_helper_funcs.prepare_fb
692 * @plane: a DRM plane
693 * @new_state: the plane's new state
695 * During plane updates, this function sets the plane's fence and
696 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
697 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
701 * a negative errno code otherwise.
704 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
705 struct drm_plane_state *new_state)
708 struct drm_gem_vram_object *gbo;
714 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
715 if (!new_state->fb->obj[i])
717 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
718 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
720 goto err_drm_gem_vram_unpin;
723 ret = drm_gem_fb_prepare_fb(plane, new_state);
725 goto err_drm_gem_vram_unpin;
729 err_drm_gem_vram_unpin:
732 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
733 drm_gem_vram_unpin(gbo);
737 EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
740 * drm_gem_vram_plane_helper_cleanup_fb() - \
741 * Implements &struct drm_plane_helper_funcs.cleanup_fb
742 * @plane: a DRM plane
743 * @old_state: the plane's old state
745 * During plane updates, this function unpins the GEM VRAM
746 * objects of the plane's old framebuffer from VRAM. Complements
747 * drm_gem_vram_plane_helper_prepare_fb().
750 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
751 struct drm_plane_state *old_state)
754 struct drm_gem_vram_object *gbo;
759 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
760 if (!old_state->fb->obj[i])
762 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
763 drm_gem_vram_unpin(gbo);
766 EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
769 * Helpers for struct drm_simple_display_pipe_funcs
773 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
774 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
775 * @pipe: a simple display pipe
776 * @new_state: the plane's new state
778 * During plane updates, this function pins the GEM VRAM
779 * objects of the plane's new framebuffer to VRAM. Call
780 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
784 * a negative errno code otherwise.
786 int drm_gem_vram_simple_display_pipe_prepare_fb(
787 struct drm_simple_display_pipe *pipe,
788 struct drm_plane_state *new_state)
790 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
792 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
795 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
796 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
797 * @pipe: a simple display pipe
798 * @old_state: the plane's old state
800 * During plane updates, this function unpins the GEM VRAM
801 * objects of the plane's old framebuffer from VRAM. Complements
802 * drm_gem_vram_simple_display_pipe_prepare_fb().
804 void drm_gem_vram_simple_display_pipe_cleanup_fb(
805 struct drm_simple_display_pipe *pipe,
806 struct drm_plane_state *old_state)
808 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
810 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
817 * drm_gem_vram_object_pin() - \
818 Implements &struct drm_gem_object_funcs.pin
819 * @gem: The GEM object to pin
823 * a negative errno code otherwise.
825 static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
827 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
829 /* Fbdev console emulation is the use case of these PRIME
830 * helpers. This may involve updating a hardware buffer from
831 * a shadow FB. We pin the buffer to it's current location
832 * (either video RAM or system memory) to prevent it from
833 * being relocated during the update operation. If you require
834 * the buffer to be pinned to VRAM, implement a callback that
835 * sets the flags accordingly.
837 return drm_gem_vram_pin(gbo, 0);
841 * drm_gem_vram_object_unpin() - \
842 Implements &struct drm_gem_object_funcs.unpin
843 * @gem: The GEM object to unpin
845 static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
847 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
849 drm_gem_vram_unpin(gbo);
853 * drm_gem_vram_object_vmap() -
854 * Implements &struct drm_gem_object_funcs.vmap
855 * @gem: The GEM object to map
856 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
860 * 0 on success, or a negative error code otherwise.
862 static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct dma_buf_map *map)
864 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
866 return drm_gem_vram_vmap(gbo, map);
870 * drm_gem_vram_object_vunmap() -
871 * Implements &struct drm_gem_object_funcs.vunmap
872 * @gem: The GEM object to unmap
873 * @map: Kernel virtual address where the VRAM GEM object was mapped
875 static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_buf_map *map)
877 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
879 drm_gem_vram_vunmap(gbo, map);
886 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
887 .free = drm_gem_vram_object_free,
888 .pin = drm_gem_vram_object_pin,
889 .unpin = drm_gem_vram_object_unpin,
890 .vmap = drm_gem_vram_object_vmap,
891 .vunmap = drm_gem_vram_object_vunmap,
892 .mmap = drm_gem_ttm_mmap,
893 .print_info = drm_gem_ttm_print_info,
897 * VRAM memory manager
904 static void bo_driver_ttm_tt_destroy(struct ttm_bo_device *bdev, struct ttm_tt *tt)
906 ttm_tt_destroy_common(bdev, tt);
915 static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
921 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
925 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached);
927 goto err_ttm_tt_init;
936 static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
937 struct ttm_placement *placement)
939 struct drm_gem_vram_object *gbo;
941 /* TTM may pass BOs that are not GEM VRAM BOs. */
942 if (!drm_is_gem_vram(bo))
945 gbo = drm_gem_vram_of_bo(bo);
947 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
950 static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo)
952 struct drm_gem_vram_object *gbo;
954 /* TTM may pass BOs that are not GEM VRAM BOs. */
955 if (!drm_is_gem_vram(bo))
958 gbo = drm_gem_vram_of_bo(bo);
960 drm_gem_vram_bo_driver_move_notify(gbo, false, NULL);
963 static int bo_driver_move(struct ttm_buffer_object *bo,
965 struct ttm_operation_ctx *ctx,
966 struct ttm_resource *new_mem,
967 struct ttm_place *hop)
969 struct drm_gem_vram_object *gbo;
971 gbo = drm_gem_vram_of_bo(bo);
973 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);
976 static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev,
977 struct ttm_resource *mem)
979 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
981 switch (mem->mem_type) {
982 case TTM_PL_SYSTEM: /* nothing to do */
985 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base;
986 mem->bus.is_iomem = true;
987 mem->bus.caching = ttm_write_combined;
996 static struct ttm_bo_driver bo_driver = {
997 .ttm_tt_create = bo_driver_ttm_tt_create,
998 .ttm_tt_destroy = bo_driver_ttm_tt_destroy,
999 .eviction_valuable = ttm_bo_eviction_valuable,
1000 .evict_flags = bo_driver_evict_flags,
1001 .move = bo_driver_move,
1002 .delete_mem_notify = bo_driver_delete_mem_notify,
1003 .io_mem_reserve = bo_driver_io_mem_reserve,
1007 * struct drm_vram_mm
1010 static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
1012 struct drm_info_node *node = (struct drm_info_node *) m->private;
1013 struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
1014 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM);
1015 struct drm_printer p = drm_seq_file_printer(m);
1017 ttm_resource_manager_debug(man, &p);
1021 static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
1022 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
1026 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
1028 * @minor: drm minor device.
1031 void drm_vram_mm_debugfs_init(struct drm_minor *minor)
1033 drm_debugfs_create_files(drm_vram_mm_debugfs_list,
1034 ARRAY_SIZE(drm_vram_mm_debugfs_list),
1035 minor->debugfs_root, minor);
1037 EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
1039 static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
1040 uint64_t vram_base, size_t vram_size)
1044 vmm->vram_base = vram_base;
1045 vmm->vram_size = vram_size;
1047 ret = ttm_bo_device_init(&vmm->bdev, &bo_driver, dev->dev,
1048 dev->anon_inode->i_mapping,
1049 dev->vma_offset_manager,
1054 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM,
1055 false, vram_size >> PAGE_SHIFT);
1062 static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1064 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM);
1065 ttm_bo_device_release(&vmm->bdev);
1069 * Helpers for integration with struct drm_device
1072 /* deprecated; use drmm_vram_mm_init() */
1073 struct drm_vram_mm *drm_vram_helper_alloc_mm(
1074 struct drm_device *dev, uint64_t vram_base, size_t vram_size)
1078 if (WARN_ON(dev->vram_mm))
1079 return dev->vram_mm;
1081 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1083 return ERR_PTR(-ENOMEM);
1085 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1089 return dev->vram_mm;
1092 kfree(dev->vram_mm);
1093 dev->vram_mm = NULL;
1094 return ERR_PTR(ret);
1096 EXPORT_SYMBOL(drm_vram_helper_alloc_mm);
1098 void drm_vram_helper_release_mm(struct drm_device *dev)
1103 drm_vram_mm_cleanup(dev->vram_mm);
1104 kfree(dev->vram_mm);
1105 dev->vram_mm = NULL;
1107 EXPORT_SYMBOL(drm_vram_helper_release_mm);
1109 static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1111 drm_vram_helper_release_mm(dev);
1115 * drmm_vram_helper_init - Initializes a device's instance of
1116 * &struct drm_vram_mm
1117 * @dev: the DRM device
1118 * @vram_base: the base address of the video memory
1119 * @vram_size: the size of the video memory in bytes
1121 * Creates a new instance of &struct drm_vram_mm and stores it in
1122 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1123 * up as part of device cleanup. Calling this function multiple times
1124 * will generate an error message.
1127 * 0 on success, or a negative errno code otherwise.
1129 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1132 struct drm_vram_mm *vram_mm;
1134 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1137 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1138 if (IS_ERR(vram_mm))
1139 return PTR_ERR(vram_mm);
1140 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1142 EXPORT_SYMBOL(drmm_vram_helper_init);
1145 * Mode-config helpers
1148 static enum drm_mode_status
1149 drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1150 const struct drm_display_mode *mode,
1151 unsigned long max_bpp)
1153 struct drm_vram_mm *vmm = dev->vram_mm;
1154 unsigned long fbsize, fbpages, max_fbpages;
1156 if (WARN_ON(!dev->vram_mm))
1159 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1161 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1162 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1164 if (fbpages > max_fbpages)
1171 * drm_vram_helper_mode_valid - Tests if a display mode's
1172 * framebuffer fits into the available video memory.
1173 * @dev: the DRM device
1174 * @mode: the mode to test
1176 * This function tests if enough video memory is available for using the
1177 * specified display mode. Atomic modesetting requires importing the
1178 * designated framebuffer into video memory before evicting the active
1179 * one. Hence, any framebuffer may consume at most half of the available
1180 * VRAM. Display modes that require a larger framebuffer can not be used,
1181 * even if the CRTC does support them. Each framebuffer is assumed to
1182 * have 32-bit color depth.
1185 * The function can only test if the display mode is supported in
1186 * general. If there are too many framebuffers pinned to video memory,
1187 * a display mode may still not be usable in practice. The color depth of
1188 * 32-bit fits all current use case. A more flexible test can be added
1192 * MODE_OK if the display mode is supported, or an error code of type
1193 * enum drm_mode_status otherwise.
1195 enum drm_mode_status
1196 drm_vram_helper_mode_valid(struct drm_device *dev,
1197 const struct drm_display_mode *mode)
1199 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1201 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1203 EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1205 MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1206 MODULE_LICENSE("GPL");