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_ioctl.h>
9 #include <drm/drm_modes.h>
10 #include <drm/ttm/ttm_bo_api.h>
11 #include <drm/ttm/ttm_bo_driver.h>
12 
13 #include <linux/dma-buf-map.h>
14 #include <linux/kernel.h> /* for container_of() */
15 
16 struct drm_mode_create_dumb;
17 struct drm_plane;
18 struct drm_plane_state;
19 struct drm_simple_display_pipe;
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 \
36 	%TTM_PL_VRAM 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 dma_buf_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 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
97 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
98 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
99 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
100 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
101 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_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 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
117 					 struct drm_device *dev,
118 					 uint32_t handle, uint64_t *offset);
119 
120 /*
121  * Helpers for struct drm_plane_helper_funcs
122  */
123 int
124 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
125 				     struct drm_plane_state *new_state);
126 void
127 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
128 				     struct drm_plane_state *old_state);
129 
130 /*
131  * Helpers for struct drm_simple_display_pipe_funcs
132  */
133 
134 int drm_gem_vram_simple_display_pipe_prepare_fb(
135 	struct drm_simple_display_pipe *pipe,
136 	struct drm_plane_state *new_state);
137 
138 void drm_gem_vram_simple_display_pipe_cleanup_fb(
139 	struct drm_simple_display_pipe *pipe,
140 	struct drm_plane_state *old_state);
141 
142 /**
143  * define DRM_GEM_VRAM_DRIVER - default callback functions for \
144 	&struct drm_driver
145  *
146  * Drivers that use VRAM MM and GEM VRAM can use this macro to initialize
147  * &struct drm_driver with default functions.
148  */
149 #define DRM_GEM_VRAM_DRIVER \
150 	.debugfs_init             = drm_vram_mm_debugfs_init, \
151 	.dumb_create		  = drm_gem_vram_driver_dumb_create, \
152 	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset, \
153 	.gem_prime_mmap		  = drm_gem_prime_mmap
154 
155 /*
156  *  VRAM memory manager
157  */
158 
159 /**
160  * struct drm_vram_mm - An instance of VRAM MM
161  * @vram_base:	Base address of the managed video memory
162  * @vram_size:	Size of the managed video memory in bytes
163  * @bdev:	The TTM BO device.
164  * @funcs:	TTM BO functions
165  *
166  * The fields &struct drm_vram_mm.vram_base and
167  * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are
168  * available for public read access. Use the field
169  * &struct drm_vram_mm.bdev to access the TTM BO device.
170  */
171 struct drm_vram_mm {
172 	uint64_t vram_base;
173 	size_t vram_size;
174 
175 	struct ttm_device bdev;
176 };
177 
178 /**
179  * drm_vram_mm_of_bdev() - \
180 	Returns the container of type &struct ttm_device for field bdev.
181  * @bdev:	the TTM BO device
182  *
183  * Returns:
184  * The containing instance of &struct drm_vram_mm
185  */
186 static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
187 	struct ttm_device *bdev)
188 {
189 	return container_of(bdev, struct drm_vram_mm, bdev);
190 }
191 
192 void drm_vram_mm_debugfs_init(struct drm_minor *minor);
193 
194 /*
195  * Helpers for integration with struct drm_device
196  */
197 
198 struct drm_vram_mm *drm_vram_helper_alloc_mm(
199 	struct drm_device *dev, uint64_t vram_base, size_t vram_size);
200 void drm_vram_helper_release_mm(struct drm_device *dev);
201 
202 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
203 			  size_t vram_size);
204 
205 /*
206  * Mode-config helpers
207  */
208 
209 enum drm_mode_status
210 drm_vram_helper_mode_valid(struct drm_device *dev,
211 			   const struct drm_display_mode *mode);
212 
213 #endif
214