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_atomic_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 #include <drm/ttm/ttm_range_manager.h>
22 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
27 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM
28 * buffer object that is backed by video RAM (VRAM). It can be used for
29 * framebuffer devices with dedicated memory.
31 * The data structure &struct drm_vram_mm and its helpers implement a memory
32 * manager for simple framebuffer devices with dedicated video memory. GEM
33 * VRAM buffer objects are either placed in the video memory or remain evicted
36 * With the GEM interface userspace applications create, manage and destroy
37 * graphics buffers, such as an on-screen framebuffer. GEM does not provide
38 * an implementation of these interfaces. It's up to the DRM driver to
39 * provide an implementation that suits the hardware. If the hardware device
40 * contains dedicated video memory, the DRM driver can use the VRAM helper
41 * library. Each active buffer object is stored in video RAM. Active
42 * buffer are used for drawing the current frame, typically something like
43 * the frame's scanout buffer or the cursor image. If there's no more space
44 * left in VRAM, inactive GEM objects can be moved to system memory.
46 * To initialize the VRAM helper library call drmm_vram_helper_alloc_mm().
47 * The function allocates and initializes an instance of &struct drm_vram_mm
48 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize
49 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize
50 * &struct file_operations; as illustrated below.
54 * struct file_operations fops ={
55 * .owner = THIS_MODULE,
56 * DRM_VRAM_MM_FILE_OPERATION
58 * struct drm_driver drv = {
59 * .driver_feature = DRM_ ... ,
64 * int init_drm_driver()
66 * struct drm_device *dev;
68 * unsigned long vram_size;
71 * // setup device, vram base and size
74 * ret = drmm_vram_helper_alloc_mm(dev, vram_base, vram_size);
80 * This creates an instance of &struct drm_vram_mm, exports DRM userspace
81 * interfaces for GEM buffer management and initializes file operations to
82 * allow for accessing created GEM buffers. With this setup, the DRM driver
83 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects
86 * You don't have to clean up the instance of VRAM MM.
87 * drmm_vram_helper_alloc_mm() is a managed interface that installs a
88 * clean-up handler to run during the DRM device's release.
90 * For drawing or scanout operations, rsp. buffer objects have to be pinned
91 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or
92 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system
93 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards.
95 * A buffer object that is pinned in video RAM has a fixed address within that
96 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically
97 * it's used to program the hardware's scanout engine for framebuffers, set
98 * the cursor overlay's image for a mouse cursor, or use it as input to the
99 * hardware's draing engine.
101 * To access a buffer object's memory from the DRM driver, call
102 * drm_gem_vram_vmap(). It maps the buffer into kernel address
103 * space and returns the memory address. Use drm_gem_vram_vunmap() to
104 * release the mapping.
108 * Buffer-objects helpers
111 static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo)
113 /* We got here via ttm_bo_put(), which means that the
114 * TTM buffer object in 'bo' has already been cleaned
115 * up; only release the GEM object.
118 WARN_ON(gbo->vmap_use_count);
119 WARN_ON(dma_buf_map_is_set(&gbo->map));
121 drm_gem_object_release(&gbo->bo.base);
124 static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo)
126 drm_gem_vram_cleanup(gbo);
130 static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo)
132 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo);
134 drm_gem_vram_destroy(gbo);
137 static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo,
138 unsigned long pl_flag)
140 u32 invariant_flags = 0;
144 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_TOPDOWN)
145 invariant_flags = TTM_PL_FLAG_TOPDOWN;
147 gbo->placement.placement = gbo->placements;
148 gbo->placement.busy_placement = gbo->placements;
150 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_VRAM) {
151 gbo->placements[c].mem_type = TTM_PL_VRAM;
152 gbo->placements[c++].flags = invariant_flags;
155 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_SYSTEM || !c) {
156 gbo->placements[c].mem_type = TTM_PL_SYSTEM;
157 gbo->placements[c++].flags = invariant_flags;
160 gbo->placement.num_placement = c;
161 gbo->placement.num_busy_placement = c;
163 for (i = 0; i < c; ++i) {
164 gbo->placements[i].fpfn = 0;
165 gbo->placements[i].lpfn = 0;
170 * drm_gem_vram_create() - Creates a VRAM-backed GEM object
171 * @dev: the DRM device
172 * @size: the buffer size in bytes
173 * @pg_align: the buffer's alignment in multiples of the page size
175 * GEM objects are allocated by calling struct drm_driver.gem_create_object,
176 * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM
177 * object functions in struct drm_driver.gem_create_object. If no functions
178 * are set, the new GEM object will use the default functions from GEM VRAM
182 * A new instance of &struct drm_gem_vram_object on success, or
183 * an ERR_PTR()-encoded error code otherwise.
185 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
187 unsigned long pg_align)
189 struct drm_gem_vram_object *gbo;
190 struct drm_gem_object *gem;
191 struct drm_vram_mm *vmm = dev->vram_mm;
192 struct ttm_device *bdev;
195 if (WARN_ONCE(!vmm, "VRAM MM not initialized"))
196 return ERR_PTR(-EINVAL);
198 if (dev->driver->gem_create_object) {
199 gem = dev->driver->gem_create_object(dev, size);
201 return ERR_PTR(-ENOMEM);
202 gbo = drm_gem_vram_of_gem(gem);
204 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
206 return ERR_PTR(-ENOMEM);
211 gem->funcs = &drm_gem_vram_object_funcs;
213 ret = drm_gem_object_init(dev, gem, size);
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, NULL, NULL,
230 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);
250 static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
252 /* Keep TTM behavior for now, remove when drivers are audited */
253 if (WARN_ON_ONCE(!gbo->bo.resource->mm_node))
256 return gbo->bo.resource->start;
260 * drm_gem_vram_offset() - \
261 Returns a GEM VRAM object's offset in video memory
262 * @gbo: the GEM VRAM object
264 * This function returns the buffer object's offset in the device's video
265 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
268 * The buffer object's offset in video memory on success, or
269 * a negative errno code otherwise.
271 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
273 if (WARN_ON_ONCE(!gbo->bo.pin_count))
275 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
277 EXPORT_SYMBOL(drm_gem_vram_offset);
279 static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo,
280 unsigned long pl_flag)
282 struct ttm_operation_ctx ctx = { false, false };
285 if (gbo->bo.pin_count)
289 drm_gem_vram_placement(gbo, pl_flag);
291 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
296 ttm_bo_pin(&gbo->bo);
302 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
303 * @gbo: the GEM VRAM object
304 * @pl_flag: a bitmask of possible memory regions
306 * Pinning a buffer object ensures that it is not evicted from
307 * a memory region. A pinned buffer object has to be unpinned before
308 * it can be pinned to another region. If the pl_flag argument is 0,
309 * the buffer is pinned at its current location (video RAM or system
312 * Small buffer objects, such as cursor images, can lead to memory
313 * fragmentation if they are pinned in the middle of video RAM. This
314 * is especially a problem on devices with only a small amount of
315 * video RAM. Fragmentation can prevent the primary framebuffer from
316 * fitting in, even though there's enough memory overall. The modifier
317 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned
318 * at the high end of the memory region to avoid fragmentation.
322 * a negative error code otherwise.
324 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
328 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
331 ret = drm_gem_vram_pin_locked(gbo, pl_flag);
332 ttm_bo_unreserve(&gbo->bo);
336 EXPORT_SYMBOL(drm_gem_vram_pin);
338 static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)
340 ttm_bo_unpin(&gbo->bo);
344 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
345 * @gbo: the GEM VRAM object
349 * a negative error code otherwise.
351 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
355 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
359 drm_gem_vram_unpin_locked(gbo);
360 ttm_bo_unreserve(&gbo->bo);
364 EXPORT_SYMBOL(drm_gem_vram_unpin);
366 static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
367 struct dma_buf_map *map)
371 if (gbo->vmap_use_count > 0)
375 * VRAM helpers unmap the BO only on demand. So the previous
376 * page mapping might still be around. Only vmap if the there's
377 * no mapping present.
379 if (dma_buf_map_is_null(&gbo->map)) {
380 ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
386 ++gbo->vmap_use_count;
392 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
393 struct dma_buf_map *map)
395 struct drm_device *dev = gbo->bo.base.dev;
397 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
400 if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
401 return; /* BUG: map not mapped from this BO */
403 if (--gbo->vmap_use_count > 0)
407 * Permanently mapping and unmapping buffers adds overhead from
408 * updating the page tables and creates debugging output. Therefore,
409 * we delay the actual unmap operation until the BO gets evicted
410 * from memory. See drm_gem_vram_bo_driver_move_notify().
415 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
417 * @gbo: The GEM VRAM object to map
418 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
421 * The vmap function pins a GEM VRAM object to its current location, either
422 * system or video memory, and maps its buffer into kernel address space.
423 * As pinned object cannot be relocated, you should avoid pinning objects
424 * permanently. Call drm_gem_vram_vunmap() with the returned address to
425 * unmap and unpin the GEM VRAM object.
428 * 0 on success, or a negative error code otherwise.
430 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
434 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
438 ret = drm_gem_vram_pin_locked(gbo, 0);
440 goto err_ttm_bo_unreserve;
441 ret = drm_gem_vram_kmap_locked(gbo, map);
443 goto err_drm_gem_vram_unpin_locked;
445 ttm_bo_unreserve(&gbo->bo);
449 err_drm_gem_vram_unpin_locked:
450 drm_gem_vram_unpin_locked(gbo);
451 err_ttm_bo_unreserve:
452 ttm_bo_unreserve(&gbo->bo);
455 EXPORT_SYMBOL(drm_gem_vram_vmap);
458 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
459 * @gbo: The GEM VRAM object to unmap
460 * @map: Kernel virtual address where the VRAM GEM object was mapped
462 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
463 * the documentation for drm_gem_vram_vmap() for more information.
465 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
469 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
470 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
473 drm_gem_vram_kunmap_locked(gbo, map);
474 drm_gem_vram_unpin_locked(gbo);
476 ttm_bo_unreserve(&gbo->bo);
478 EXPORT_SYMBOL(drm_gem_vram_vunmap);
481 * drm_gem_vram_fill_create_dumb() - \
482 Helper for implementing &struct drm_driver.dumb_create
483 * @file: the DRM file
484 * @dev: the DRM device
485 * @pg_align: the buffer's alignment in multiples of the page size
486 * @pitch_align: the scanline's alignment in powers of 2
487 * @args: the arguments as provided to \
488 &struct drm_driver.dumb_create
490 * This helper function fills &struct drm_mode_create_dumb, which is used
491 * by &struct drm_driver.dumb_create. Implementations of this interface
492 * should forwards their arguments to this helper, plus the driver-specific
497 * a negative error code otherwise.
499 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
500 struct drm_device *dev,
501 unsigned long pg_align,
502 unsigned long pitch_align,
503 struct drm_mode_create_dumb *args)
506 struct drm_gem_vram_object *gbo;
510 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
512 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
514 pitch = ALIGN(pitch, pitch_align);
516 size = pitch * args->height;
518 size = roundup(size, PAGE_SIZE);
522 gbo = drm_gem_vram_create(dev, size, pg_align);
526 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
528 goto err_drm_gem_object_put;
530 drm_gem_object_put(&gbo->bo.base);
534 args->handle = handle;
538 err_drm_gem_object_put:
539 drm_gem_object_put(&gbo->bo.base);
542 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
545 * Helpers for struct ttm_device_funcs
548 static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
550 return (bo->destroy == ttm_buffer_object_destroy);
553 static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
554 struct ttm_placement *pl)
556 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
557 *pl = gbo->placement;
560 static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo)
562 struct ttm_buffer_object *bo = &gbo->bo;
563 struct drm_device *dev = bo->base.dev;
565 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
568 ttm_bo_vunmap(bo, &gbo->map);
569 dma_buf_map_clear(&gbo->map); /* explicitly clear mapping for next vmap call */
572 static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
574 struct ttm_operation_ctx *ctx,
575 struct ttm_resource *new_mem)
577 drm_gem_vram_bo_driver_move_notify(gbo);
578 return ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem);
582 * Helpers for struct drm_gem_object_funcs
586 * drm_gem_vram_object_free() - \
587 Implements &struct drm_gem_object_funcs.free
588 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
590 static void drm_gem_vram_object_free(struct drm_gem_object *gem)
592 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
594 drm_gem_vram_put(gbo);
598 * Helpers for dump buffers
602 * drm_gem_vram_driver_dumb_create() - \
603 Implements &struct drm_driver.dumb_create
604 * @file: the DRM file
605 * @dev: the DRM device
606 * @args: the arguments as provided to \
607 &struct drm_driver.dumb_create
609 * This function requires the driver to use @drm_device.vram_mm for its
610 * instance of VRAM MM.
614 * a negative error code otherwise.
616 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
617 struct drm_device *dev,
618 struct drm_mode_create_dumb *args)
620 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
623 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
625 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
628 * Helpers for struct drm_plane_helper_funcs
632 * drm_gem_vram_plane_helper_prepare_fb() - \
633 * Implements &struct drm_plane_helper_funcs.prepare_fb
634 * @plane: a DRM plane
635 * @new_state: the plane's new state
637 * During plane updates, this function sets the plane's fence and
638 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
639 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
643 * a negative errno code otherwise.
646 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
647 struct drm_plane_state *new_state)
650 struct drm_gem_vram_object *gbo;
656 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
657 if (!new_state->fb->obj[i])
659 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
660 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
662 goto err_drm_gem_vram_unpin;
665 ret = drm_gem_plane_helper_prepare_fb(plane, new_state);
667 goto err_drm_gem_vram_unpin;
671 err_drm_gem_vram_unpin:
674 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
675 drm_gem_vram_unpin(gbo);
679 EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
682 * drm_gem_vram_plane_helper_cleanup_fb() - \
683 * Implements &struct drm_plane_helper_funcs.cleanup_fb
684 * @plane: a DRM plane
685 * @old_state: the plane's old state
687 * During plane updates, this function unpins the GEM VRAM
688 * objects of the plane's old framebuffer from VRAM. Complements
689 * drm_gem_vram_plane_helper_prepare_fb().
692 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
693 struct drm_plane_state *old_state)
696 struct drm_gem_vram_object *gbo;
701 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
702 if (!old_state->fb->obj[i])
704 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
705 drm_gem_vram_unpin(gbo);
708 EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
711 * Helpers for struct drm_simple_display_pipe_funcs
715 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
716 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
717 * @pipe: a simple display pipe
718 * @new_state: the plane's new state
720 * During plane updates, this function pins the GEM VRAM
721 * objects of the plane's new framebuffer to VRAM. Call
722 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
726 * a negative errno code otherwise.
728 int drm_gem_vram_simple_display_pipe_prepare_fb(
729 struct drm_simple_display_pipe *pipe,
730 struct drm_plane_state *new_state)
732 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
734 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
737 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
738 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
739 * @pipe: a simple display pipe
740 * @old_state: the plane's old state
742 * During plane updates, this function unpins the GEM VRAM
743 * objects of the plane's old framebuffer from VRAM. Complements
744 * drm_gem_vram_simple_display_pipe_prepare_fb().
746 void drm_gem_vram_simple_display_pipe_cleanup_fb(
747 struct drm_simple_display_pipe *pipe,
748 struct drm_plane_state *old_state)
750 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
752 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
759 * drm_gem_vram_object_pin() - \
760 Implements &struct drm_gem_object_funcs.pin
761 * @gem: The GEM object to pin
765 * a negative errno code otherwise.
767 static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
769 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
771 /* Fbdev console emulation is the use case of these PRIME
772 * helpers. This may involve updating a hardware buffer from
773 * a shadow FB. We pin the buffer to it's current location
774 * (either video RAM or system memory) to prevent it from
775 * being relocated during the update operation. If you require
776 * the buffer to be pinned to VRAM, implement a callback that
777 * sets the flags accordingly.
779 return drm_gem_vram_pin(gbo, 0);
783 * drm_gem_vram_object_unpin() - \
784 Implements &struct drm_gem_object_funcs.unpin
785 * @gem: The GEM object to unpin
787 static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
789 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
791 drm_gem_vram_unpin(gbo);
795 * drm_gem_vram_object_vmap() -
796 * Implements &struct drm_gem_object_funcs.vmap
797 * @gem: The GEM object to map
798 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
802 * 0 on success, or a negative error code otherwise.
804 static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct dma_buf_map *map)
806 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
808 return drm_gem_vram_vmap(gbo, map);
812 * drm_gem_vram_object_vunmap() -
813 * Implements &struct drm_gem_object_funcs.vunmap
814 * @gem: The GEM object to unmap
815 * @map: Kernel virtual address where the VRAM GEM object was mapped
817 static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_buf_map *map)
819 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
821 drm_gem_vram_vunmap(gbo, map);
828 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
829 .free = drm_gem_vram_object_free,
830 .pin = drm_gem_vram_object_pin,
831 .unpin = drm_gem_vram_object_unpin,
832 .vmap = drm_gem_vram_object_vmap,
833 .vunmap = drm_gem_vram_object_vunmap,
834 .mmap = drm_gem_ttm_mmap,
835 .print_info = drm_gem_ttm_print_info,
839 * VRAM memory manager
846 static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt)
848 ttm_tt_destroy_common(bdev, tt);
857 static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
863 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
867 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached);
869 goto err_ttm_tt_init;
878 static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
879 struct ttm_placement *placement)
881 struct drm_gem_vram_object *gbo;
883 /* TTM may pass BOs that are not GEM VRAM BOs. */
884 if (!drm_is_gem_vram(bo))
887 gbo = drm_gem_vram_of_bo(bo);
889 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
892 static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo)
894 struct drm_gem_vram_object *gbo;
896 /* TTM may pass BOs that are not GEM VRAM BOs. */
897 if (!drm_is_gem_vram(bo))
900 gbo = drm_gem_vram_of_bo(bo);
902 drm_gem_vram_bo_driver_move_notify(gbo);
905 static int bo_driver_move(struct ttm_buffer_object *bo,
907 struct ttm_operation_ctx *ctx,
908 struct ttm_resource *new_mem,
909 struct ttm_place *hop)
911 struct drm_gem_vram_object *gbo;
913 gbo = drm_gem_vram_of_bo(bo);
915 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);
918 static int bo_driver_io_mem_reserve(struct ttm_device *bdev,
919 struct ttm_resource *mem)
921 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
923 switch (mem->mem_type) {
924 case TTM_PL_SYSTEM: /* nothing to do */
927 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base;
928 mem->bus.is_iomem = true;
929 mem->bus.caching = ttm_write_combined;
938 static struct ttm_device_funcs bo_driver = {
939 .ttm_tt_create = bo_driver_ttm_tt_create,
940 .ttm_tt_destroy = bo_driver_ttm_tt_destroy,
941 .eviction_valuable = ttm_bo_eviction_valuable,
942 .evict_flags = bo_driver_evict_flags,
943 .move = bo_driver_move,
944 .delete_mem_notify = bo_driver_delete_mem_notify,
945 .io_mem_reserve = bo_driver_io_mem_reserve,
952 static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
954 struct drm_info_node *node = (struct drm_info_node *) m->private;
955 struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
956 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM);
957 struct drm_printer p = drm_seq_file_printer(m);
959 ttm_resource_manager_debug(man, &p);
963 static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
964 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
968 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
970 * @minor: drm minor device.
973 void drm_vram_mm_debugfs_init(struct drm_minor *minor)
975 drm_debugfs_create_files(drm_vram_mm_debugfs_list,
976 ARRAY_SIZE(drm_vram_mm_debugfs_list),
977 minor->debugfs_root, minor);
979 EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
981 static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
982 uint64_t vram_base, size_t vram_size)
986 vmm->vram_base = vram_base;
987 vmm->vram_size = vram_size;
989 ret = ttm_device_init(&vmm->bdev, &bo_driver, dev->dev,
990 dev->anon_inode->i_mapping,
991 dev->vma_offset_manager,
996 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM,
997 false, vram_size >> PAGE_SHIFT);
1004 static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1006 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM);
1007 ttm_device_fini(&vmm->bdev);
1011 * Helpers for integration with struct drm_device
1014 /* deprecated; use drmm_vram_mm_init() */
1015 struct drm_vram_mm *drm_vram_helper_alloc_mm(
1016 struct drm_device *dev, uint64_t vram_base, size_t vram_size)
1020 if (WARN_ON(dev->vram_mm))
1021 return dev->vram_mm;
1023 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1025 return ERR_PTR(-ENOMEM);
1027 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1031 return dev->vram_mm;
1034 kfree(dev->vram_mm);
1035 dev->vram_mm = NULL;
1036 return ERR_PTR(ret);
1038 EXPORT_SYMBOL(drm_vram_helper_alloc_mm);
1040 void drm_vram_helper_release_mm(struct drm_device *dev)
1045 drm_vram_mm_cleanup(dev->vram_mm);
1046 kfree(dev->vram_mm);
1047 dev->vram_mm = NULL;
1049 EXPORT_SYMBOL(drm_vram_helper_release_mm);
1051 static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1053 drm_vram_helper_release_mm(dev);
1057 * drmm_vram_helper_init - Initializes a device's instance of
1058 * &struct drm_vram_mm
1059 * @dev: the DRM device
1060 * @vram_base: the base address of the video memory
1061 * @vram_size: the size of the video memory in bytes
1063 * Creates a new instance of &struct drm_vram_mm and stores it in
1064 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1065 * up as part of device cleanup. Calling this function multiple times
1066 * will generate an error message.
1069 * 0 on success, or a negative errno code otherwise.
1071 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1074 struct drm_vram_mm *vram_mm;
1076 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1079 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1080 if (IS_ERR(vram_mm))
1081 return PTR_ERR(vram_mm);
1082 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1084 EXPORT_SYMBOL(drmm_vram_helper_init);
1087 * Mode-config helpers
1090 static enum drm_mode_status
1091 drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1092 const struct drm_display_mode *mode,
1093 unsigned long max_bpp)
1095 struct drm_vram_mm *vmm = dev->vram_mm;
1096 unsigned long fbsize, fbpages, max_fbpages;
1098 if (WARN_ON(!dev->vram_mm))
1101 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1103 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1104 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1106 if (fbpages > max_fbpages)
1113 * drm_vram_helper_mode_valid - Tests if a display mode's
1114 * framebuffer fits into the available video memory.
1115 * @dev: the DRM device
1116 * @mode: the mode to test
1118 * This function tests if enough video memory is available for using the
1119 * specified display mode. Atomic modesetting requires importing the
1120 * designated framebuffer into video memory before evicting the active
1121 * one. Hence, any framebuffer may consume at most half of the available
1122 * VRAM. Display modes that require a larger framebuffer can not be used,
1123 * even if the CRTC does support them. Each framebuffer is assumed to
1124 * have 32-bit color depth.
1127 * The function can only test if the display mode is supported in
1128 * general. If there are too many framebuffers pinned to video memory,
1129 * a display mode may still not be usable in practice. The color depth of
1130 * 32-bit fits all current use case. A more flexible test can be added
1134 * MODE_OK if the display mode is supported, or an error code of type
1135 * enum drm_mode_status otherwise.
1137 enum drm_mode_status
1138 drm_vram_helper_mode_valid(struct drm_device *dev,
1139 const struct drm_display_mode *mode)
1141 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1143 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1145 EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1147 MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1148 MODULE_LICENSE("GPL");