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/ttm/ttm_bo_api.h>
10 #include <drm/ttm/ttm_bo_driver.h>
11 #include <drm/ttm/ttm_placement.h>
12 
13 #include <linux/kernel.h> /* for container_of() */
14 
15 struct drm_mode_create_dumb;
16 struct drm_plane;
17 struct drm_plane_state;
18 struct drm_simple_display_pipe;
19 struct filp;
20 struct vm_area_struct;
21 
22 #define DRM_GEM_VRAM_PL_FLAG_VRAM	TTM_PL_FLAG_VRAM
23 #define DRM_GEM_VRAM_PL_FLAG_SYSTEM	TTM_PL_FLAG_SYSTEM
24 #define DRM_GEM_VRAM_PL_FLAG_TOPDOWN	TTM_PL_FLAG_TOPDOWN
25 
26 /*
27  * Buffer-object helpers
28  */
29 
30 /**
31  * struct drm_gem_vram_object - GEM object backed by VRAM
32  * @gem:	GEM object
33  * @bo:		TTM buffer object
34  * @kmap:	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  * @pin_count:	Pin counter
39  *
40  * The type struct drm_gem_vram_object represents a GEM object that is
41  * backed by VRAM. It can be used for simple framebuffer devices with
42  * dedicated memory. The buffer object can be evicted to system memory if
43  * video memory becomes scarce.
44  *
45  * GEM VRAM objects perform reference counting for pin and mapping
46  * operations. So a buffer object that has been pinned N times with
47  * drm_gem_vram_pin() must be unpinned N times with
48  * drm_gem_vram_unpin(). The same applies to pairs of
49  * drm_gem_vram_kmap() and drm_gem_vram_kunmap(), as well as pairs of
50  * drm_gem_vram_vmap() and drm_gem_vram_vunmap().
51  */
52 struct drm_gem_vram_object {
53 	struct ttm_buffer_object bo;
54 	struct ttm_bo_kmap_obj kmap;
55 
56 	/**
57 	 * @kmap_use_count:
58 	 *
59 	 * Reference count on the virtual address.
60 	 * The address are un-mapped when the count reaches zero.
61 	 */
62 	unsigned int kmap_use_count;
63 
64 	/* Supported placements are %TTM_PL_VRAM and %TTM_PL_SYSTEM */
65 	struct ttm_placement placement;
66 	struct ttm_place placements[2];
67 
68 	int pin_count;
69 };
70 
71 /**
72  * Returns the container of type &struct drm_gem_vram_object
73  * for field bo.
74  * @bo:		the VRAM buffer object
75  * Returns:	The containing GEM VRAM object
76  */
77 static inline struct drm_gem_vram_object *drm_gem_vram_of_bo(
78 	struct ttm_buffer_object *bo)
79 {
80 	return container_of(bo, struct drm_gem_vram_object, bo);
81 }
82 
83 /**
84  * Returns the container of type &struct drm_gem_vram_object
85  * for field gem.
86  * @gem:	the GEM object
87  * Returns:	The containing GEM VRAM object
88  */
89 static inline struct drm_gem_vram_object *drm_gem_vram_of_gem(
90 	struct drm_gem_object *gem)
91 {
92 	return container_of(gem, struct drm_gem_vram_object, bo.base);
93 }
94 
95 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev,
96 						size_t size,
97 						unsigned long pg_align);
98 void drm_gem_vram_put(struct drm_gem_vram_object *gbo);
99 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
100 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
101 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
102 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
103 void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
104 			bool *is_iomem);
105 void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo);
106 void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo);
107 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr);
108 
109 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
110 				  struct drm_device *dev,
111 				  unsigned long pg_align,
112 				  unsigned long pitch_align,
113 				  struct drm_mode_create_dumb *args);
114 
115 /*
116  * Helpers for struct drm_driver
117  */
118 
119 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
120 				    struct drm_device *dev,
121 				    struct drm_mode_create_dumb *args);
122 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
123 					 struct drm_device *dev,
124 					 uint32_t handle, uint64_t *offset);
125 
126 /*
127  * Helpers for struct drm_plane_helper_funcs
128  */
129 int
130 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
131 				     struct drm_plane_state *new_state);
132 void
133 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
134 				     struct drm_plane_state *old_state);
135 
136 /*
137  * Helpers for struct drm_simple_display_pipe_funcs
138  */
139 
140 int drm_gem_vram_simple_display_pipe_prepare_fb(
141 	struct drm_simple_display_pipe *pipe,
142 	struct drm_plane_state *new_state);
143 
144 void drm_gem_vram_simple_display_pipe_cleanup_fb(
145 	struct drm_simple_display_pipe *pipe,
146 	struct drm_plane_state *old_state);
147 
148 /**
149  * define DRM_GEM_VRAM_DRIVER - default callback functions for \
150 	&struct drm_driver
151  *
152  * Drivers that use VRAM MM and GEM VRAM can use this macro to initialize
153  * &struct drm_driver with default functions.
154  */
155 #define DRM_GEM_VRAM_DRIVER \
156 	.debugfs_init             = drm_vram_mm_debugfs_init, \
157 	.dumb_create		  = drm_gem_vram_driver_dumb_create, \
158 	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset, \
159 	.gem_prime_mmap		  = drm_gem_prime_mmap
160 
161 /*
162  *  VRAM memory manager
163  */
164 
165 /**
166  * struct drm_vram_mm - An instance of VRAM MM
167  * @vram_base:	Base address of the managed video memory
168  * @vram_size:	Size of the managed video memory in bytes
169  * @bdev:	The TTM BO device.
170  * @funcs:	TTM BO functions
171  *
172  * The fields &struct drm_vram_mm.vram_base and
173  * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are
174  * available for public read access. Use the field
175  * &struct drm_vram_mm.bdev to access the TTM BO device.
176  */
177 struct drm_vram_mm {
178 	uint64_t vram_base;
179 	size_t vram_size;
180 
181 	struct ttm_bo_device bdev;
182 };
183 
184 /**
185  * drm_vram_mm_of_bdev() - \
186 	Returns the container of type &struct ttm_bo_device for field bdev.
187  * @bdev:	the TTM BO device
188  *
189  * Returns:
190  * The containing instance of &struct drm_vram_mm
191  */
192 static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
193 	struct ttm_bo_device *bdev)
194 {
195 	return container_of(bdev, struct drm_vram_mm, bdev);
196 }
197 
198 int drm_vram_mm_debugfs_init(struct drm_minor *minor);
199 
200 /*
201  * Helpers for integration with struct drm_device
202  */
203 
204 struct drm_vram_mm *drm_vram_helper_alloc_mm(
205 	struct drm_device *dev, uint64_t vram_base, size_t vram_size);
206 void drm_vram_helper_release_mm(struct drm_device *dev);
207 
208 #endif
209