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)
390 ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
395 ++gbo->vmap_use_count;
401 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
402 struct dma_buf_map *map)
404 struct drm_device *dev = gbo->bo.base.dev;
406 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
409 if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
410 return; /* BUG: map not mapped from this BO */
412 if (--gbo->vmap_use_count > 0)
416 * Permanently mapping and unmapping buffers adds overhead from
417 * updating the page tables and creates debugging output. Therefore,
418 * we delay the actual unmap operation until the BO gets evicted
419 * from memory. See drm_gem_vram_bo_driver_move_notify().
424 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
426 * @gbo: The GEM VRAM object to map
427 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
430 * The vmap function pins a GEM VRAM object to its current location, either
431 * system or video memory, and maps its buffer into kernel address space.
432 * As pinned object cannot be relocated, you should avoid pinning objects
433 * permanently. Call drm_gem_vram_vunmap() with the returned address to
434 * unmap and unpin the GEM VRAM object.
437 * 0 on success, or a negative error code otherwise.
439 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
443 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
447 ret = drm_gem_vram_pin_locked(gbo, 0);
449 goto err_ttm_bo_unreserve;
450 ret = drm_gem_vram_kmap_locked(gbo, map);
452 goto err_drm_gem_vram_unpin_locked;
454 ttm_bo_unreserve(&gbo->bo);
458 err_drm_gem_vram_unpin_locked:
459 drm_gem_vram_unpin_locked(gbo);
460 err_ttm_bo_unreserve:
461 ttm_bo_unreserve(&gbo->bo);
464 EXPORT_SYMBOL(drm_gem_vram_vmap);
467 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
468 * @gbo: The GEM VRAM object to unmap
469 * @map: Kernel virtual address where the VRAM GEM object was mapped
471 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
472 * the documentation for drm_gem_vram_vmap() for more information.
474 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
478 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
479 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
482 drm_gem_vram_kunmap_locked(gbo, map);
483 drm_gem_vram_unpin_locked(gbo);
485 ttm_bo_unreserve(&gbo->bo);
487 EXPORT_SYMBOL(drm_gem_vram_vunmap);
490 * drm_gem_vram_fill_create_dumb() - \
491 Helper for implementing &struct drm_driver.dumb_create
492 * @file: the DRM file
493 * @dev: the DRM device
494 * @pg_align: the buffer's alignment in multiples of the page size
495 * @pitch_align: the scanline's alignment in powers of 2
496 * @args: the arguments as provided to \
497 &struct drm_driver.dumb_create
499 * This helper function fills &struct drm_mode_create_dumb, which is used
500 * by &struct drm_driver.dumb_create. Implementations of this interface
501 * should forwards their arguments to this helper, plus the driver-specific
506 * a negative error code otherwise.
508 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
509 struct drm_device *dev,
510 unsigned long pg_align,
511 unsigned long pitch_align,
512 struct drm_mode_create_dumb *args)
515 struct drm_gem_vram_object *gbo;
519 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
521 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
523 pitch = ALIGN(pitch, pitch_align);
525 size = pitch * args->height;
527 size = roundup(size, PAGE_SIZE);
531 gbo = drm_gem_vram_create(dev, size, pg_align);
535 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
537 goto err_drm_gem_object_put;
539 drm_gem_object_put(&gbo->bo.base);
543 args->handle = handle;
547 err_drm_gem_object_put:
548 drm_gem_object_put(&gbo->bo.base);
551 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
554 * Helpers for struct ttm_bo_driver
557 static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
559 return (bo->destroy == ttm_buffer_object_destroy);
562 static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
563 struct ttm_placement *pl)
565 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
566 *pl = gbo->placement;
569 static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo,
571 struct ttm_resource *new_mem)
573 struct ttm_buffer_object *bo = &gbo->bo;
574 struct drm_device *dev = bo->base.dev;
576 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
579 ttm_bo_vunmap(bo, &gbo->map);
582 static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
584 struct ttm_operation_ctx *ctx,
585 struct ttm_resource *new_mem)
589 drm_gem_vram_bo_driver_move_notify(gbo, evict, new_mem);
590 ret = ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem);
592 swap(*new_mem, gbo->bo.mem);
593 drm_gem_vram_bo_driver_move_notify(gbo, false, new_mem);
594 swap(*new_mem, gbo->bo.mem);
600 * Helpers for struct drm_gem_object_funcs
604 * drm_gem_vram_object_free() - \
605 Implements &struct drm_gem_object_funcs.free
606 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
608 static void drm_gem_vram_object_free(struct drm_gem_object *gem)
610 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
612 drm_gem_vram_put(gbo);
616 * Helpers for dump buffers
620 * drm_gem_vram_driver_dumb_create() - \
621 Implements &struct drm_driver.dumb_create
622 * @file: the DRM file
623 * @dev: the DRM device
624 * @args: the arguments as provided to \
625 &struct drm_driver.dumb_create
627 * This function requires the driver to use @drm_device.vram_mm for its
628 * instance of VRAM MM.
632 * a negative error code otherwise.
634 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
635 struct drm_device *dev,
636 struct drm_mode_create_dumb *args)
638 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
641 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
643 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
646 * drm_gem_vram_driver_dumb_mmap_offset() - \
647 Implements &struct drm_driver.dumb_mmap_offset
648 * @file: DRM file pointer.
650 * @handle: GEM handle
651 * @offset: Returns the mapping's memory offset on success
655 * a negative errno code otherwise.
657 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
658 struct drm_device *dev,
659 uint32_t handle, uint64_t *offset)
661 struct drm_gem_object *gem;
662 struct drm_gem_vram_object *gbo;
664 gem = drm_gem_object_lookup(file, handle);
668 gbo = drm_gem_vram_of_gem(gem);
669 *offset = drm_gem_vram_mmap_offset(gbo);
671 drm_gem_object_put(gem);
675 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
678 * Helpers for struct drm_plane_helper_funcs
682 * drm_gem_vram_plane_helper_prepare_fb() - \
683 * Implements &struct drm_plane_helper_funcs.prepare_fb
684 * @plane: a DRM plane
685 * @new_state: the plane's new state
687 * During plane updates, this function sets the plane's fence and
688 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
689 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
693 * a negative errno code otherwise.
696 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
697 struct drm_plane_state *new_state)
700 struct drm_gem_vram_object *gbo;
706 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
707 if (!new_state->fb->obj[i])
709 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
710 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
712 goto err_drm_gem_vram_unpin;
715 ret = drm_gem_fb_prepare_fb(plane, new_state);
717 goto err_drm_gem_vram_unpin;
721 err_drm_gem_vram_unpin:
724 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
725 drm_gem_vram_unpin(gbo);
729 EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
732 * drm_gem_vram_plane_helper_cleanup_fb() - \
733 * Implements &struct drm_plane_helper_funcs.cleanup_fb
734 * @plane: a DRM plane
735 * @old_state: the plane's old state
737 * During plane updates, this function unpins the GEM VRAM
738 * objects of the plane's old framebuffer from VRAM. Complements
739 * drm_gem_vram_plane_helper_prepare_fb().
742 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
743 struct drm_plane_state *old_state)
746 struct drm_gem_vram_object *gbo;
751 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
752 if (!old_state->fb->obj[i])
754 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
755 drm_gem_vram_unpin(gbo);
758 EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
761 * Helpers for struct drm_simple_display_pipe_funcs
765 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
766 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
767 * @pipe: a simple display pipe
768 * @new_state: the plane's new state
770 * During plane updates, this function pins the GEM VRAM
771 * objects of the plane's new framebuffer to VRAM. Call
772 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
776 * a negative errno code otherwise.
778 int drm_gem_vram_simple_display_pipe_prepare_fb(
779 struct drm_simple_display_pipe *pipe,
780 struct drm_plane_state *new_state)
782 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
784 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
787 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
788 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
789 * @pipe: a simple display pipe
790 * @old_state: the plane's old state
792 * During plane updates, this function unpins the GEM VRAM
793 * objects of the plane's old framebuffer from VRAM. Complements
794 * drm_gem_vram_simple_display_pipe_prepare_fb().
796 void drm_gem_vram_simple_display_pipe_cleanup_fb(
797 struct drm_simple_display_pipe *pipe,
798 struct drm_plane_state *old_state)
800 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
802 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
809 * drm_gem_vram_object_pin() - \
810 Implements &struct drm_gem_object_funcs.pin
811 * @gem: The GEM object to pin
815 * a negative errno code otherwise.
817 static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
819 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
821 /* Fbdev console emulation is the use case of these PRIME
822 * helpers. This may involve updating a hardware buffer from
823 * a shadow FB. We pin the buffer to it's current location
824 * (either video RAM or system memory) to prevent it from
825 * being relocated during the update operation. If you require
826 * the buffer to be pinned to VRAM, implement a callback that
827 * sets the flags accordingly.
829 return drm_gem_vram_pin(gbo, 0);
833 * drm_gem_vram_object_unpin() - \
834 Implements &struct drm_gem_object_funcs.unpin
835 * @gem: The GEM object to unpin
837 static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
839 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
841 drm_gem_vram_unpin(gbo);
845 * drm_gem_vram_object_vmap() -
846 * Implements &struct drm_gem_object_funcs.vmap
847 * @gem: The GEM object to map
848 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
852 * 0 on success, or a negative error code otherwise.
854 static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct dma_buf_map *map)
856 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
858 return drm_gem_vram_vmap(gbo, map);
862 * drm_gem_vram_object_vunmap() -
863 * Implements &struct drm_gem_object_funcs.vunmap
864 * @gem: The GEM object to unmap
865 * @map: Kernel virtual address where the VRAM GEM object was mapped
867 static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_buf_map *map)
869 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
871 drm_gem_vram_vunmap(gbo, map);
878 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
879 .free = drm_gem_vram_object_free,
880 .pin = drm_gem_vram_object_pin,
881 .unpin = drm_gem_vram_object_unpin,
882 .vmap = drm_gem_vram_object_vmap,
883 .vunmap = drm_gem_vram_object_vunmap,
884 .mmap = drm_gem_ttm_mmap,
885 .print_info = drm_gem_ttm_print_info,
889 * VRAM memory manager
896 static void bo_driver_ttm_tt_destroy(struct ttm_bo_device *bdev, struct ttm_tt *tt)
898 ttm_tt_destroy_common(bdev, tt);
907 static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
913 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
917 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached);
919 goto err_ttm_tt_init;
928 static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
929 struct ttm_placement *placement)
931 struct drm_gem_vram_object *gbo;
933 /* TTM may pass BOs that are not GEM VRAM BOs. */
934 if (!drm_is_gem_vram(bo))
937 gbo = drm_gem_vram_of_bo(bo);
939 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
942 static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo)
944 struct drm_gem_vram_object *gbo;
946 /* TTM may pass BOs that are not GEM VRAM BOs. */
947 if (!drm_is_gem_vram(bo))
950 gbo = drm_gem_vram_of_bo(bo);
952 drm_gem_vram_bo_driver_move_notify(gbo, false, NULL);
955 static int bo_driver_move(struct ttm_buffer_object *bo,
957 struct ttm_operation_ctx *ctx,
958 struct ttm_resource *new_mem,
959 struct ttm_place *hop)
961 struct drm_gem_vram_object *gbo;
963 gbo = drm_gem_vram_of_bo(bo);
965 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);
968 static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev,
969 struct ttm_resource *mem)
971 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
973 switch (mem->mem_type) {
974 case TTM_PL_SYSTEM: /* nothing to do */
977 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base;
978 mem->bus.is_iomem = true;
979 mem->bus.caching = ttm_write_combined;
988 static struct ttm_bo_driver bo_driver = {
989 .ttm_tt_create = bo_driver_ttm_tt_create,
990 .ttm_tt_destroy = bo_driver_ttm_tt_destroy,
991 .eviction_valuable = ttm_bo_eviction_valuable,
992 .evict_flags = bo_driver_evict_flags,
993 .move = bo_driver_move,
994 .delete_mem_notify = bo_driver_delete_mem_notify,
995 .io_mem_reserve = bo_driver_io_mem_reserve,
1002 static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
1004 struct drm_info_node *node = (struct drm_info_node *) m->private;
1005 struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
1006 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM);
1007 struct drm_printer p = drm_seq_file_printer(m);
1009 ttm_resource_manager_debug(man, &p);
1013 static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
1014 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
1018 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
1020 * @minor: drm minor device.
1023 void drm_vram_mm_debugfs_init(struct drm_minor *minor)
1025 drm_debugfs_create_files(drm_vram_mm_debugfs_list,
1026 ARRAY_SIZE(drm_vram_mm_debugfs_list),
1027 minor->debugfs_root, minor);
1029 EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
1031 static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
1032 uint64_t vram_base, size_t vram_size)
1036 vmm->vram_base = vram_base;
1037 vmm->vram_size = vram_size;
1039 ret = ttm_bo_device_init(&vmm->bdev, &bo_driver, dev->dev,
1040 dev->anon_inode->i_mapping,
1041 dev->vma_offset_manager,
1046 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM,
1047 false, vram_size >> PAGE_SHIFT);
1054 static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1056 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM);
1057 ttm_bo_device_release(&vmm->bdev);
1061 * Helpers for integration with struct drm_device
1064 /* deprecated; use drmm_vram_mm_init() */
1065 struct drm_vram_mm *drm_vram_helper_alloc_mm(
1066 struct drm_device *dev, uint64_t vram_base, size_t vram_size)
1070 if (WARN_ON(dev->vram_mm))
1071 return dev->vram_mm;
1073 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1075 return ERR_PTR(-ENOMEM);
1077 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1081 return dev->vram_mm;
1084 kfree(dev->vram_mm);
1085 dev->vram_mm = NULL;
1086 return ERR_PTR(ret);
1088 EXPORT_SYMBOL(drm_vram_helper_alloc_mm);
1090 void drm_vram_helper_release_mm(struct drm_device *dev)
1095 drm_vram_mm_cleanup(dev->vram_mm);
1096 kfree(dev->vram_mm);
1097 dev->vram_mm = NULL;
1099 EXPORT_SYMBOL(drm_vram_helper_release_mm);
1101 static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1103 drm_vram_helper_release_mm(dev);
1107 * drmm_vram_helper_init - Initializes a device's instance of
1108 * &struct drm_vram_mm
1109 * @dev: the DRM device
1110 * @vram_base: the base address of the video memory
1111 * @vram_size: the size of the video memory in bytes
1113 * Creates a new instance of &struct drm_vram_mm and stores it in
1114 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1115 * up as part of device cleanup. Calling this function multiple times
1116 * will generate an error message.
1119 * 0 on success, or a negative errno code otherwise.
1121 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1124 struct drm_vram_mm *vram_mm;
1126 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1129 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1130 if (IS_ERR(vram_mm))
1131 return PTR_ERR(vram_mm);
1132 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1134 EXPORT_SYMBOL(drmm_vram_helper_init);
1137 * Mode-config helpers
1140 static enum drm_mode_status
1141 drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1142 const struct drm_display_mode *mode,
1143 unsigned long max_bpp)
1145 struct drm_vram_mm *vmm = dev->vram_mm;
1146 unsigned long fbsize, fbpages, max_fbpages;
1148 if (WARN_ON(!dev->vram_mm))
1151 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1153 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1154 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1156 if (fbpages > max_fbpages)
1163 * drm_vram_helper_mode_valid - Tests if a display mode's
1164 * framebuffer fits into the available video memory.
1165 * @dev: the DRM device
1166 * @mode: the mode to test
1168 * This function tests if enough video memory is available for using the
1169 * specified display mode. Atomic modesetting requires importing the
1170 * designated framebuffer into video memory before evicting the active
1171 * one. Hence, any framebuffer may consume at most half of the available
1172 * VRAM. Display modes that require a larger framebuffer can not be used,
1173 * even if the CRTC does support them. Each framebuffer is assumed to
1174 * have 32-bit color depth.
1177 * The function can only test if the display mode is supported in
1178 * general. If there are too many framebuffers pinned to video memory,
1179 * a display mode may still not be usable in practice. The color depth of
1180 * 32-bit fits all current use case. A more flexible test can be added
1184 * MODE_OK if the display mode is supported, or an error code of type
1185 * enum drm_mode_status otherwise.
1187 enum drm_mode_status
1188 drm_vram_helper_mode_valid(struct drm_device *dev,
1189 const struct drm_display_mode *mode)
1191 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1193 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1195 EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1197 MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1198 MODULE_LICENSE("GPL");