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 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_device *bdev;
193 if (WARN_ONCE(!vmm, "VRAM MM not initialized"))
194 return ERR_PTR(-EINVAL);
196 if (dev->driver->gem_create_object) {
197 gem = dev->driver->gem_create_object(dev, size);
199 return ERR_PTR(-ENOMEM);
200 gbo = drm_gem_vram_of_gem(gem);
202 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL);
204 return ERR_PTR(-ENOMEM);
209 gem->funcs = &drm_gem_vram_object_funcs;
211 ret = drm_gem_object_init(dev, gem, size);
220 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
223 * A failing ttm_bo_init will call ttm_buffer_object_destroy
224 * to release gbo->bo.base and kfree gbo.
226 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device,
227 &gbo->placement, pg_align, false, NULL, NULL,
228 ttm_buffer_object_destroy);
234 EXPORT_SYMBOL(drm_gem_vram_create);
237 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object
238 * @gbo: the GEM VRAM object
240 * See ttm_bo_put() for more information.
242 void drm_gem_vram_put(struct drm_gem_vram_object *gbo)
244 ttm_bo_put(&gbo->bo);
246 EXPORT_SYMBOL(drm_gem_vram_put);
249 * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset
250 * @gbo: the GEM VRAM object
252 * See drm_vma_node_offset_addr() for more information.
255 * The buffer object's offset for userspace mappings on success, or
256 * 0 if no offset is allocated.
258 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo)
260 return drm_vma_node_offset_addr(&gbo->bo.base.vma_node);
262 EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
264 static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
266 /* Keep TTM behavior for now, remove when drivers are audited */
267 if (WARN_ON_ONCE(!gbo->bo.mem.mm_node))
270 return gbo->bo.mem.start;
274 * drm_gem_vram_offset() - \
275 Returns a GEM VRAM object's offset in video memory
276 * @gbo: the GEM VRAM object
278 * This function returns the buffer object's offset in the device's video
279 * memory. The buffer object has to be pinned to %TTM_PL_VRAM.
282 * The buffer object's offset in video memory on success, or
283 * a negative errno code otherwise.
285 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo)
287 if (WARN_ON_ONCE(!gbo->bo.pin_count))
289 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
291 EXPORT_SYMBOL(drm_gem_vram_offset);
293 static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo,
294 unsigned long pl_flag)
296 struct ttm_operation_ctx ctx = { false, false };
299 if (gbo->bo.pin_count)
303 drm_gem_vram_placement(gbo, pl_flag);
305 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx);
310 ttm_bo_pin(&gbo->bo);
316 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region.
317 * @gbo: the GEM VRAM object
318 * @pl_flag: a bitmask of possible memory regions
320 * Pinning a buffer object ensures that it is not evicted from
321 * a memory region. A pinned buffer object has to be unpinned before
322 * it can be pinned to another region. If the pl_flag argument is 0,
323 * the buffer is pinned at its current location (video RAM or system
326 * Small buffer objects, such as cursor images, can lead to memory
327 * fragmentation if they are pinned in the middle of video RAM. This
328 * is especially a problem on devices with only a small amount of
329 * video RAM. Fragmentation can prevent the primary framebuffer from
330 * fitting in, even though there's enough memory overall. The modifier
331 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned
332 * at the high end of the memory region to avoid fragmentation.
336 * a negative error code otherwise.
338 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag)
342 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
345 ret = drm_gem_vram_pin_locked(gbo, pl_flag);
346 ttm_bo_unreserve(&gbo->bo);
350 EXPORT_SYMBOL(drm_gem_vram_pin);
352 static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)
354 ttm_bo_unpin(&gbo->bo);
358 * drm_gem_vram_unpin() - Unpins a GEM VRAM object
359 * @gbo: the GEM VRAM object
363 * a negative error code otherwise.
365 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
369 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
373 drm_gem_vram_unpin_locked(gbo);
374 ttm_bo_unreserve(&gbo->bo);
378 EXPORT_SYMBOL(drm_gem_vram_unpin);
380 static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
381 struct dma_buf_map *map)
385 if (gbo->vmap_use_count > 0)
389 * VRAM helpers unmap the BO only on demand. So the previous
390 * page mapping might still be around. Only vmap if the there's
391 * no mapping present.
393 if (dma_buf_map_is_null(&gbo->map)) {
394 ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
400 ++gbo->vmap_use_count;
406 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
407 struct dma_buf_map *map)
409 struct drm_device *dev = gbo->bo.base.dev;
411 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
414 if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
415 return; /* BUG: map not mapped from this BO */
417 if (--gbo->vmap_use_count > 0)
421 * Permanently mapping and unmapping buffers adds overhead from
422 * updating the page tables and creates debugging output. Therefore,
423 * we delay the actual unmap operation until the BO gets evicted
424 * from memory. See drm_gem_vram_bo_driver_move_notify().
429 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
431 * @gbo: The GEM VRAM object to map
432 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
435 * The vmap function pins a GEM VRAM object to its current location, either
436 * system or video memory, and maps its buffer into kernel address space.
437 * As pinned object cannot be relocated, you should avoid pinning objects
438 * permanently. Call drm_gem_vram_vunmap() with the returned address to
439 * unmap and unpin the GEM VRAM object.
442 * 0 on success, or a negative error code otherwise.
444 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
448 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
452 ret = drm_gem_vram_pin_locked(gbo, 0);
454 goto err_ttm_bo_unreserve;
455 ret = drm_gem_vram_kmap_locked(gbo, map);
457 goto err_drm_gem_vram_unpin_locked;
459 ttm_bo_unreserve(&gbo->bo);
463 err_drm_gem_vram_unpin_locked:
464 drm_gem_vram_unpin_locked(gbo);
465 err_ttm_bo_unreserve:
466 ttm_bo_unreserve(&gbo->bo);
469 EXPORT_SYMBOL(drm_gem_vram_vmap);
472 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
473 * @gbo: The GEM VRAM object to unmap
474 * @map: Kernel virtual address where the VRAM GEM object was mapped
476 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
477 * the documentation for drm_gem_vram_vmap() for more information.
479 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
483 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
484 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
487 drm_gem_vram_kunmap_locked(gbo, map);
488 drm_gem_vram_unpin_locked(gbo);
490 ttm_bo_unreserve(&gbo->bo);
492 EXPORT_SYMBOL(drm_gem_vram_vunmap);
495 * drm_gem_vram_fill_create_dumb() - \
496 Helper for implementing &struct drm_driver.dumb_create
497 * @file: the DRM file
498 * @dev: the DRM device
499 * @pg_align: the buffer's alignment in multiples of the page size
500 * @pitch_align: the scanline's alignment in powers of 2
501 * @args: the arguments as provided to \
502 &struct drm_driver.dumb_create
504 * This helper function fills &struct drm_mode_create_dumb, which is used
505 * by &struct drm_driver.dumb_create. Implementations of this interface
506 * should forwards their arguments to this helper, plus the driver-specific
511 * a negative error code otherwise.
513 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
514 struct drm_device *dev,
515 unsigned long pg_align,
516 unsigned long pitch_align,
517 struct drm_mode_create_dumb *args)
520 struct drm_gem_vram_object *gbo;
524 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
526 if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
528 pitch = ALIGN(pitch, pitch_align);
530 size = pitch * args->height;
532 size = roundup(size, PAGE_SIZE);
536 gbo = drm_gem_vram_create(dev, size, pg_align);
540 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle);
542 goto err_drm_gem_object_put;
544 drm_gem_object_put(&gbo->bo.base);
548 args->handle = handle;
552 err_drm_gem_object_put:
553 drm_gem_object_put(&gbo->bo.base);
556 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb);
559 * Helpers for struct ttm_device_funcs
562 static bool drm_is_gem_vram(struct ttm_buffer_object *bo)
564 return (bo->destroy == ttm_buffer_object_destroy);
567 static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo,
568 struct ttm_placement *pl)
570 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM);
571 *pl = gbo->placement;
574 static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo)
576 struct ttm_buffer_object *bo = &gbo->bo;
577 struct drm_device *dev = bo->base.dev;
579 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
582 ttm_bo_vunmap(bo, &gbo->map);
583 dma_buf_map_clear(&gbo->map); /* explicitly clear mapping for next vmap call */
586 static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
588 struct ttm_operation_ctx *ctx,
589 struct ttm_resource *new_mem)
591 drm_gem_vram_bo_driver_move_notify(gbo);
592 return ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem);
596 * Helpers for struct drm_gem_object_funcs
600 * drm_gem_vram_object_free() - \
601 Implements &struct drm_gem_object_funcs.free
602 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem
604 static void drm_gem_vram_object_free(struct drm_gem_object *gem)
606 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
608 drm_gem_vram_put(gbo);
612 * Helpers for dump buffers
616 * drm_gem_vram_driver_dumb_create() - \
617 Implements &struct drm_driver.dumb_create
618 * @file: the DRM file
619 * @dev: the DRM device
620 * @args: the arguments as provided to \
621 &struct drm_driver.dumb_create
623 * This function requires the driver to use @drm_device.vram_mm for its
624 * instance of VRAM MM.
628 * a negative error code otherwise.
630 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
631 struct drm_device *dev,
632 struct drm_mode_create_dumb *args)
634 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
637 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args);
639 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
642 * drm_gem_vram_driver_dumb_mmap_offset() - \
643 Implements &struct drm_driver.dumb_mmap_offset
644 * @file: DRM file pointer.
646 * @handle: GEM handle
647 * @offset: Returns the mapping's memory offset on success
651 * a negative errno code otherwise.
653 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
654 struct drm_device *dev,
655 uint32_t handle, uint64_t *offset)
657 struct drm_gem_object *gem;
658 struct drm_gem_vram_object *gbo;
660 gem = drm_gem_object_lookup(file, handle);
664 gbo = drm_gem_vram_of_gem(gem);
665 *offset = drm_gem_vram_mmap_offset(gbo);
667 drm_gem_object_put(gem);
671 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
674 * Helpers for struct drm_plane_helper_funcs
678 * drm_gem_vram_plane_helper_prepare_fb() - \
679 * Implements &struct drm_plane_helper_funcs.prepare_fb
680 * @plane: a DRM plane
681 * @new_state: the plane's new state
683 * During plane updates, this function sets the plane's fence and
684 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM.
685 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
689 * a negative errno code otherwise.
692 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
693 struct drm_plane_state *new_state)
696 struct drm_gem_vram_object *gbo;
702 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
703 if (!new_state->fb->obj[i])
705 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
706 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
708 goto err_drm_gem_vram_unpin;
711 ret = drm_gem_plane_helper_prepare_fb(plane, new_state);
713 goto err_drm_gem_vram_unpin;
717 err_drm_gem_vram_unpin:
720 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
721 drm_gem_vram_unpin(gbo);
725 EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
728 * drm_gem_vram_plane_helper_cleanup_fb() - \
729 * Implements &struct drm_plane_helper_funcs.cleanup_fb
730 * @plane: a DRM plane
731 * @old_state: the plane's old state
733 * During plane updates, this function unpins the GEM VRAM
734 * objects of the plane's old framebuffer from VRAM. Complements
735 * drm_gem_vram_plane_helper_prepare_fb().
738 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
739 struct drm_plane_state *old_state)
742 struct drm_gem_vram_object *gbo;
747 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
748 if (!old_state->fb->obj[i])
750 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
751 drm_gem_vram_unpin(gbo);
754 EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
757 * Helpers for struct drm_simple_display_pipe_funcs
761 * drm_gem_vram_simple_display_pipe_prepare_fb() - \
762 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb
763 * @pipe: a simple display pipe
764 * @new_state: the plane's new state
766 * During plane updates, this function pins the GEM VRAM
767 * objects of the plane's new framebuffer to VRAM. Call
768 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
772 * a negative errno code otherwise.
774 int drm_gem_vram_simple_display_pipe_prepare_fb(
775 struct drm_simple_display_pipe *pipe,
776 struct drm_plane_state *new_state)
778 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
780 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
783 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
784 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
785 * @pipe: a simple display pipe
786 * @old_state: the plane's old state
788 * During plane updates, this function unpins the GEM VRAM
789 * objects of the plane's old framebuffer from VRAM. Complements
790 * drm_gem_vram_simple_display_pipe_prepare_fb().
792 void drm_gem_vram_simple_display_pipe_cleanup_fb(
793 struct drm_simple_display_pipe *pipe,
794 struct drm_plane_state *old_state)
796 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
798 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
805 * drm_gem_vram_object_pin() - \
806 Implements &struct drm_gem_object_funcs.pin
807 * @gem: The GEM object to pin
811 * a negative errno code otherwise.
813 static int drm_gem_vram_object_pin(struct drm_gem_object *gem)
815 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
817 /* Fbdev console emulation is the use case of these PRIME
818 * helpers. This may involve updating a hardware buffer from
819 * a shadow FB. We pin the buffer to it's current location
820 * (either video RAM or system memory) to prevent it from
821 * being relocated during the update operation. If you require
822 * the buffer to be pinned to VRAM, implement a callback that
823 * sets the flags accordingly.
825 return drm_gem_vram_pin(gbo, 0);
829 * drm_gem_vram_object_unpin() - \
830 Implements &struct drm_gem_object_funcs.unpin
831 * @gem: The GEM object to unpin
833 static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)
835 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
837 drm_gem_vram_unpin(gbo);
841 * drm_gem_vram_object_vmap() -
842 * Implements &struct drm_gem_object_funcs.vmap
843 * @gem: The GEM object to map
844 * @map: Returns the kernel virtual address of the VRAM GEM object's backing
848 * 0 on success, or a negative error code otherwise.
850 static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct dma_buf_map *map)
852 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
854 return drm_gem_vram_vmap(gbo, map);
858 * drm_gem_vram_object_vunmap() -
859 * Implements &struct drm_gem_object_funcs.vunmap
860 * @gem: The GEM object to unmap
861 * @map: Kernel virtual address where the VRAM GEM object was mapped
863 static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_buf_map *map)
865 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
867 drm_gem_vram_vunmap(gbo, map);
874 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
875 .free = drm_gem_vram_object_free,
876 .pin = drm_gem_vram_object_pin,
877 .unpin = drm_gem_vram_object_unpin,
878 .vmap = drm_gem_vram_object_vmap,
879 .vunmap = drm_gem_vram_object_vunmap,
880 .mmap = drm_gem_ttm_mmap,
881 .print_info = drm_gem_ttm_print_info,
885 * VRAM memory manager
892 static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt)
894 ttm_tt_destroy_common(bdev, tt);
903 static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo,
909 tt = kzalloc(sizeof(*tt), GFP_KERNEL);
913 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached);
915 goto err_ttm_tt_init;
924 static void bo_driver_evict_flags(struct ttm_buffer_object *bo,
925 struct ttm_placement *placement)
927 struct drm_gem_vram_object *gbo;
929 /* TTM may pass BOs that are not GEM VRAM BOs. */
930 if (!drm_is_gem_vram(bo))
933 gbo = drm_gem_vram_of_bo(bo);
935 drm_gem_vram_bo_driver_evict_flags(gbo, placement);
938 static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo)
940 struct drm_gem_vram_object *gbo;
942 /* TTM may pass BOs that are not GEM VRAM BOs. */
943 if (!drm_is_gem_vram(bo))
946 gbo = drm_gem_vram_of_bo(bo);
948 drm_gem_vram_bo_driver_move_notify(gbo);
951 static int bo_driver_move(struct ttm_buffer_object *bo,
953 struct ttm_operation_ctx *ctx,
954 struct ttm_resource *new_mem,
955 struct ttm_place *hop)
957 struct drm_gem_vram_object *gbo;
959 gbo = drm_gem_vram_of_bo(bo);
961 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);
964 static int bo_driver_io_mem_reserve(struct ttm_device *bdev,
965 struct ttm_resource *mem)
967 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
969 switch (mem->mem_type) {
970 case TTM_PL_SYSTEM: /* nothing to do */
973 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base;
974 mem->bus.is_iomem = true;
975 mem->bus.caching = ttm_write_combined;
984 static struct ttm_device_funcs bo_driver = {
985 .ttm_tt_create = bo_driver_ttm_tt_create,
986 .ttm_tt_destroy = bo_driver_ttm_tt_destroy,
987 .eviction_valuable = ttm_bo_eviction_valuable,
988 .evict_flags = bo_driver_evict_flags,
989 .move = bo_driver_move,
990 .delete_mem_notify = bo_driver_delete_mem_notify,
991 .io_mem_reserve = bo_driver_io_mem_reserve,
998 static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
1000 struct drm_info_node *node = (struct drm_info_node *) m->private;
1001 struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
1002 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM);
1003 struct drm_printer p = drm_seq_file_printer(m);
1005 ttm_resource_manager_debug(man, &p);
1009 static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
1010 { "vram-mm", drm_vram_mm_debugfs, 0, NULL },
1014 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
1016 * @minor: drm minor device.
1019 void drm_vram_mm_debugfs_init(struct drm_minor *minor)
1021 drm_debugfs_create_files(drm_vram_mm_debugfs_list,
1022 ARRAY_SIZE(drm_vram_mm_debugfs_list),
1023 minor->debugfs_root, minor);
1025 EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
1027 static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
1028 uint64_t vram_base, size_t vram_size)
1032 vmm->vram_base = vram_base;
1033 vmm->vram_size = vram_size;
1035 ret = ttm_device_init(&vmm->bdev, &bo_driver, dev->dev,
1036 dev->anon_inode->i_mapping,
1037 dev->vma_offset_manager,
1042 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM,
1043 false, vram_size >> PAGE_SHIFT);
1050 static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm)
1052 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM);
1053 ttm_device_fini(&vmm->bdev);
1057 * Helpers for integration with struct drm_device
1060 /* deprecated; use drmm_vram_mm_init() */
1061 struct drm_vram_mm *drm_vram_helper_alloc_mm(
1062 struct drm_device *dev, uint64_t vram_base, size_t vram_size)
1066 if (WARN_ON(dev->vram_mm))
1067 return dev->vram_mm;
1069 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL);
1071 return ERR_PTR(-ENOMEM);
1073 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size);
1077 return dev->vram_mm;
1080 kfree(dev->vram_mm);
1081 dev->vram_mm = NULL;
1082 return ERR_PTR(ret);
1084 EXPORT_SYMBOL(drm_vram_helper_alloc_mm);
1086 void drm_vram_helper_release_mm(struct drm_device *dev)
1091 drm_vram_mm_cleanup(dev->vram_mm);
1092 kfree(dev->vram_mm);
1093 dev->vram_mm = NULL;
1095 EXPORT_SYMBOL(drm_vram_helper_release_mm);
1097 static void drm_vram_mm_release(struct drm_device *dev, void *ptr)
1099 drm_vram_helper_release_mm(dev);
1103 * drmm_vram_helper_init - Initializes a device's instance of
1104 * &struct drm_vram_mm
1105 * @dev: the DRM device
1106 * @vram_base: the base address of the video memory
1107 * @vram_size: the size of the video memory in bytes
1109 * Creates a new instance of &struct drm_vram_mm and stores it in
1110 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned
1111 * up as part of device cleanup. Calling this function multiple times
1112 * will generate an error message.
1115 * 0 on success, or a negative errno code otherwise.
1117 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
1120 struct drm_vram_mm *vram_mm;
1122 if (drm_WARN_ON_ONCE(dev, dev->vram_mm))
1125 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size);
1126 if (IS_ERR(vram_mm))
1127 return PTR_ERR(vram_mm);
1128 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL);
1130 EXPORT_SYMBOL(drmm_vram_helper_init);
1133 * Mode-config helpers
1136 static enum drm_mode_status
1137 drm_vram_helper_mode_valid_internal(struct drm_device *dev,
1138 const struct drm_display_mode *mode,
1139 unsigned long max_bpp)
1141 struct drm_vram_mm *vmm = dev->vram_mm;
1142 unsigned long fbsize, fbpages, max_fbpages;
1144 if (WARN_ON(!dev->vram_mm))
1147 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT;
1149 fbsize = mode->hdisplay * mode->vdisplay * max_bpp;
1150 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE);
1152 if (fbpages > max_fbpages)
1159 * drm_vram_helper_mode_valid - Tests if a display mode's
1160 * framebuffer fits into the available video memory.
1161 * @dev: the DRM device
1162 * @mode: the mode to test
1164 * This function tests if enough video memory is available for using the
1165 * specified display mode. Atomic modesetting requires importing the
1166 * designated framebuffer into video memory before evicting the active
1167 * one. Hence, any framebuffer may consume at most half of the available
1168 * VRAM. Display modes that require a larger framebuffer can not be used,
1169 * even if the CRTC does support them. Each framebuffer is assumed to
1170 * have 32-bit color depth.
1173 * The function can only test if the display mode is supported in
1174 * general. If there are too many framebuffers pinned to video memory,
1175 * a display mode may still not be usable in practice. The color depth of
1176 * 32-bit fits all current use case. A more flexible test can be added
1180 * MODE_OK if the display mode is supported, or an error code of type
1181 * enum drm_mode_status otherwise.
1183 enum drm_mode_status
1184 drm_vram_helper_mode_valid(struct drm_device *dev,
1185 const struct drm_display_mode *mode)
1187 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */
1189 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp);
1191 EXPORT_SYMBOL(drm_vram_helper_mode_valid);
1193 MODULE_DESCRIPTION("DRM VRAM memory-management helpers");
1194 MODULE_LICENSE("GPL");