xref: /linux/include/drm/drm_gem_vram_helper.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 
3 #ifndef DRM_GEM_VRAM_HELPER_H
4 #define DRM_GEM_VRAM_HELPER_H
5 
6 #include <drm/drm_file.h>
7 #include <drm/drm_gem.h>
8 #include <drm/drm_gem_ttm_helper.h>
9 #include <drm/drm_ioctl.h>
10 #include <drm/drm_modes.h>
11 #include <drm/ttm/ttm_bo.h>
12 #include <drm/ttm/ttm_placement.h>
13 
14 #include <linux/container_of.h>
15 #include <linux/iosys-map.h>
16 
17 struct drm_mode_create_dumb;
18 struct drm_plane;
19 struct drm_plane_state;
20 struct filp;
21 struct vm_area_struct;
22 
23 #define DRM_GEM_VRAM_PL_FLAG_SYSTEM	(1 << 0)
24 #define DRM_GEM_VRAM_PL_FLAG_VRAM	(1 << 1)
25 #define DRM_GEM_VRAM_PL_FLAG_TOPDOWN	(1 << 2)
26 
27 /*
28  * Buffer-object helpers
29  */
30 
31 /**
32  * struct drm_gem_vram_object - GEM object backed by VRAM
33  * @bo:		TTM buffer object
34  * @map:	Mapping information for @bo
35  * @placement:	TTM placement information. Supported placements are %TTM_PL_VRAM
36  *		and %TTM_PL_SYSTEM
37  * @placements:	TTM placement information.
38  *
39  * The type struct drm_gem_vram_object represents a GEM object that is
40  * backed by VRAM. It can be used for simple framebuffer devices with
41  * dedicated memory. The buffer object can be evicted to system memory if
42  * video memory becomes scarce.
43  *
44  * GEM VRAM objects perform reference counting for pin and mapping
45  * operations. So a buffer object that has been pinned N times with
46  * drm_gem_vram_pin() must be unpinned N times with
47  * drm_gem_vram_unpin(). The same applies to pairs of
48  * drm_gem_vram_kmap() and drm_gem_vram_kunmap(), as well as pairs of
49  * drm_gem_vram_vmap() and drm_gem_vram_vunmap().
50  */
51 struct drm_gem_vram_object {
52 	struct ttm_buffer_object bo;
53 	struct iosys_map map;
54 
55 	/**
56 	 * @vmap_use_count:
57 	 *
58 	 * Reference count on the virtual address.
59 	 * The address are un-mapped when the count reaches zero.
60 	 */
61 	unsigned int vmap_use_count;
62 
63 	/* Supported placements are %TTM_PL_VRAM and %TTM_PL_SYSTEM */
64 	struct ttm_placement placement;
65 	struct ttm_place placements[2];
66 };
67 
68 /**
69  * drm_gem_vram_of_bo - Returns the container of type
70  * &struct drm_gem_vram_object for field bo.
71  * @bo:		the VRAM buffer object
72  * Returns:	The containing GEM VRAM object
73  */
74 static inline struct drm_gem_vram_object *drm_gem_vram_of_bo(
75 	struct ttm_buffer_object *bo)
76 {
77 	return container_of(bo, struct drm_gem_vram_object, bo);
78 }
79 
80 /**
81  * drm_gem_vram_of_gem - Returns the container of type
82  * &struct drm_gem_vram_object for field gem.
83  * @gem:	the GEM object
84  * Returns:	The containing GEM VRAM object
85  */
86 static inline struct drm_gem_vram_object *drm_gem_vram_of_gem(
87 	struct drm_gem_object *gem)
88 {
89 	return container_of(gem, struct drm_gem_vram_object, bo.base);
90 }
91 
92 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
93 						size_t size,
94 						unsigned long pg_align);
95 void drm_gem_vram_put(struct drm_gem_vram_object *gbo);
96 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
97 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
98 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
99 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map);
100 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo,
101 			 struct iosys_map *map);
102 
103 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
104 				  struct drm_device *dev,
105 				  unsigned long pg_align,
106 				  unsigned long pitch_align,
107 				  struct drm_mode_create_dumb *args);
108 
109 /*
110  * Helpers for struct drm_driver
111  */
112 
113 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
114 				    struct drm_device *dev,
115 				    struct drm_mode_create_dumb *args);
116 
117 /*
118  * Helpers for struct drm_plane_helper_funcs
119  */
120 int
121 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
122 				     struct drm_plane_state *new_state);
123 void
124 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
125 				     struct drm_plane_state *old_state);
126 
127 /**
128  * DRM_GEM_VRAM_PLANE_HELPER_FUNCS - Initializes struct drm_plane_helper_funcs
129  *				     for VRAM handling
130  *
131  * Drivers may use GEM BOs as VRAM helpers for the framebuffer memory. This
132  * macro initializes struct drm_plane_helper_funcs to use the respective helper
133  * functions.
134  */
135 #define DRM_GEM_VRAM_PLANE_HELPER_FUNCS \
136 	.prepare_fb = drm_gem_vram_plane_helper_prepare_fb, \
137 	.cleanup_fb = drm_gem_vram_plane_helper_cleanup_fb
138 
139 /**
140  * define DRM_GEM_VRAM_DRIVER - default callback functions for
141  *				&struct drm_driver
142  *
143  * Drivers that use VRAM MM and GEM VRAM can use this macro to initialize
144  * &struct drm_driver with default functions.
145  */
146 #define DRM_GEM_VRAM_DRIVER \
147 	.debugfs_init	 = drm_vram_mm_debugfs_init, \
148 	.dumb_create	 = drm_gem_vram_driver_dumb_create, \
149 	.dumb_map_offset = drm_gem_ttm_dumb_map_offset
150 
151 /*
152  *  VRAM memory manager
153  */
154 
155 /**
156  * struct drm_vram_mm - An instance of VRAM MM
157  * @vram_base:	Base address of the managed video memory
158  * @vram_size:	Size of the managed video memory in bytes
159  * @bdev:	The TTM BO device.
160  *
161  * The fields &struct drm_vram_mm.vram_base and
162  * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are
163  * available for public read access. Use the field
164  * &struct drm_vram_mm.bdev to access the TTM BO device.
165  */
166 struct drm_vram_mm {
167 	uint64_t vram_base;
168 	size_t vram_size;
169 
170 	struct ttm_device bdev;
171 };
172 
173 /**
174  * drm_vram_mm_of_bdev() - Returns the container of type &struct ttm_device for
175  *			   field bdev.
176  * @bdev:	the TTM BO device
177  *
178  * Returns:
179  * The containing instance of &struct drm_vram_mm
180  */
181 static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
182 	struct ttm_device *bdev)
183 {
184 	return container_of(bdev, struct drm_vram_mm, bdev);
185 }
186 
187 void drm_vram_mm_debugfs_init(struct drm_minor *minor);
188 
189 /*
190  * Helpers for integration with struct drm_device
191  */
192 
193 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
194 			  size_t vram_size);
195 
196 /*
197  * Mode-config helpers
198  */
199 
200 enum drm_mode_status
201 drm_vram_helper_mode_valid(struct drm_device *dev,
202 			   const struct drm_display_mode *mode);
203 
204 #endif
205