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 #include <drm/ttm/ttm_placement.h>
13 
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_VRAM	TTM_PL_FLAG_VRAM
24 #define DRM_GEM_VRAM_PL_FLAG_SYSTEM	TTM_PL_FLAG_SYSTEM
25 #define DRM_GEM_VRAM_PL_FLAG_TOPDOWN	TTM_PL_FLAG_TOPDOWN
26 
27 /*
28  * Buffer-object helpers
29  */
30 
31 /**
32  * struct drm_gem_vram_object - GEM object backed by VRAM
33  * @gem:	GEM object
34  * @bo:		TTM buffer object
35  * @kmap:	Mapping information for @bo
36  * @placement:	TTM placement information. Supported placements are \
37 	%TTM_PL_VRAM and %TTM_PL_SYSTEM
38  * @placements:	TTM placement information.
39  * @pin_count:	Pin counter
40  *
41  * The type struct drm_gem_vram_object represents a GEM object that is
42  * backed by VRAM. It can be used for simple framebuffer devices with
43  * dedicated memory. The buffer object can be evicted to system memory if
44  * video memory becomes scarce.
45  *
46  * GEM VRAM objects perform reference counting for pin and mapping
47  * operations. So a buffer object that has been pinned N times with
48  * drm_gem_vram_pin() must be unpinned N times with
49  * drm_gem_vram_unpin(). The same applies to pairs of
50  * drm_gem_vram_kmap() and drm_gem_vram_kunmap(), as well as pairs of
51  * drm_gem_vram_vmap() and drm_gem_vram_vunmap().
52  */
53 struct drm_gem_vram_object {
54 	struct ttm_buffer_object bo;
55 	struct ttm_bo_kmap_obj kmap;
56 
57 	/**
58 	 * @kmap_use_count:
59 	 *
60 	 * Reference count on the virtual address.
61 	 * The address are un-mapped when the count reaches zero.
62 	 */
63 	unsigned int kmap_use_count;
64 
65 	/* Supported placements are %TTM_PL_VRAM and %TTM_PL_SYSTEM */
66 	struct ttm_placement placement;
67 	struct ttm_place placements[2];
68 
69 	int pin_count;
70 };
71 
72 /**
73  * Returns the container of type &struct drm_gem_vram_object
74  * for field bo.
75  * @bo:		the VRAM buffer object
76  * Returns:	The containing GEM VRAM object
77  */
78 static inline struct drm_gem_vram_object *drm_gem_vram_of_bo(
79 	struct ttm_buffer_object *bo)
80 {
81 	return container_of(bo, struct drm_gem_vram_object, bo);
82 }
83 
84 /**
85  * Returns the container of type &struct drm_gem_vram_object
86  * for field gem.
87  * @gem:	the GEM object
88  * Returns:	The containing GEM VRAM object
89  */
90 static inline struct drm_gem_vram_object *drm_gem_vram_of_gem(
91 	struct drm_gem_object *gem)
92 {
93 	return container_of(gem, struct drm_gem_vram_object, bo.base);
94 }
95 
96 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
97 						size_t size,
98 						unsigned long pg_align);
99 void drm_gem_vram_put(struct drm_gem_vram_object *gbo);
100 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
101 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
102 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
103 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
104 void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
105 			bool *is_iomem);
106 void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo);
107 void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo);
108 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr);
109 
110 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
111 				  struct drm_device *dev,
112 				  unsigned long pg_align,
113 				  unsigned long pitch_align,
114 				  struct drm_mode_create_dumb *args);
115 
116 /*
117  * Helpers for struct drm_driver
118  */
119 
120 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
121 				    struct drm_device *dev,
122 				    struct drm_mode_create_dumb *args);
123 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
124 					 struct drm_device *dev,
125 					 uint32_t handle, uint64_t *offset);
126 
127 /*
128  * Helpers for struct drm_plane_helper_funcs
129  */
130 int
131 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
132 				     struct drm_plane_state *new_state);
133 void
134 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
135 				     struct drm_plane_state *old_state);
136 
137 /*
138  * Helpers for struct drm_simple_display_pipe_funcs
139  */
140 
141 int drm_gem_vram_simple_display_pipe_prepare_fb(
142 	struct drm_simple_display_pipe *pipe,
143 	struct drm_plane_state *new_state);
144 
145 void drm_gem_vram_simple_display_pipe_cleanup_fb(
146 	struct drm_simple_display_pipe *pipe,
147 	struct drm_plane_state *old_state);
148 
149 /**
150  * define DRM_GEM_VRAM_DRIVER - default callback functions for \
151 	&struct drm_driver
152  *
153  * Drivers that use VRAM MM and GEM VRAM can use this macro to initialize
154  * &struct drm_driver with default functions.
155  */
156 #define DRM_GEM_VRAM_DRIVER \
157 	.debugfs_init             = drm_vram_mm_debugfs_init, \
158 	.dumb_create		  = drm_gem_vram_driver_dumb_create, \
159 	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset, \
160 	.gem_prime_mmap		  = drm_gem_prime_mmap
161 
162 /*
163  *  VRAM memory manager
164  */
165 
166 /**
167  * struct drm_vram_mm - An instance of VRAM MM
168  * @vram_base:	Base address of the managed video memory
169  * @vram_size:	Size of the managed video memory in bytes
170  * @bdev:	The TTM BO device.
171  * @funcs:	TTM BO functions
172  *
173  * The fields &struct drm_vram_mm.vram_base and
174  * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are
175  * available for public read access. Use the field
176  * &struct drm_vram_mm.bdev to access the TTM BO device.
177  */
178 struct drm_vram_mm {
179 	uint64_t vram_base;
180 	size_t vram_size;
181 
182 	struct ttm_bo_device bdev;
183 };
184 
185 /**
186  * drm_vram_mm_of_bdev() - \
187 	Returns the container of type &struct ttm_bo_device for field bdev.
188  * @bdev:	the TTM BO device
189  *
190  * Returns:
191  * The containing instance of &struct drm_vram_mm
192  */
193 static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
194 	struct ttm_bo_device *bdev)
195 {
196 	return container_of(bdev, struct drm_vram_mm, bdev);
197 }
198 
199 void drm_vram_mm_debugfs_init(struct drm_minor *minor);
200 
201 /*
202  * Helpers for integration with struct drm_device
203  */
204 
205 struct drm_vram_mm *drm_vram_helper_alloc_mm(
206 	struct drm_device *dev, uint64_t vram_base, size_t vram_size);
207 void drm_vram_helper_release_mm(struct drm_device *dev);
208 
209 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base,
210 			  size_t vram_size);
211 
212 /*
213  * Mode-config helpers
214  */
215 
216 enum drm_mode_status
217 drm_vram_helper_mode_valid(struct drm_device *dev,
218 			   const struct drm_display_mode *mode);
219 
220 #endif
221