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 drm_vram_mm_funcs;
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 						struct ttm_bo_device *bdev,
98 						size_t size,
99 						unsigned long pg_align,
100 						bool interruptible);
101 void drm_gem_vram_put(struct drm_gem_vram_object *gbo);
102 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
103 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
104 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
105 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
106 void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
107 			bool *is_iomem);
108 void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo);
109 void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo);
110 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr);
111 
112 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
113 				  struct drm_device *dev,
114 				  struct ttm_bo_device *bdev,
115 				  unsigned long pg_align,
116 				  bool interruptible,
117 				  struct drm_mode_create_dumb *args);
118 
119 /*
120  * Helpers for struct drm_driver
121  */
122 
123 int drm_gem_vram_driver_dumb_create(struct drm_file *file,
124 				    struct drm_device *dev,
125 				    struct drm_mode_create_dumb *args);
126 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
127 					 struct drm_device *dev,
128 					 uint32_t handle, uint64_t *offset);
129 
130 /*
131  * Helpers for struct drm_plane_helper_funcs
132  */
133 int
134 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
135 				     struct drm_plane_state *new_state);
136 void
137 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
138 				     struct drm_plane_state *old_state);
139 
140 /*
141  * Helpers for struct drm_simple_display_pipe_funcs
142  */
143 
144 int drm_gem_vram_simple_display_pipe_prepare_fb(
145 	struct drm_simple_display_pipe *pipe,
146 	struct drm_plane_state *new_state);
147 
148 void drm_gem_vram_simple_display_pipe_cleanup_fb(
149 	struct drm_simple_display_pipe *pipe,
150 	struct drm_plane_state *old_state);
151 
152 /**
153  * define DRM_GEM_VRAM_DRIVER - default callback functions for \
154 	&struct drm_driver
155  *
156  * Drivers that use VRAM MM and GEM VRAM can use this macro to initialize
157  * &struct drm_driver with default functions.
158  */
159 #define DRM_GEM_VRAM_DRIVER \
160 	.debugfs_init             = drm_vram_mm_debugfs_init, \
161 	.dumb_create		  = drm_gem_vram_driver_dumb_create, \
162 	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset, \
163 	.gem_prime_mmap		  = drm_gem_prime_mmap
164 
165 /*
166  *  VRAM memory manager
167  */
168 
169 /**
170  * struct drm_vram_mm - An instance of VRAM MM
171  * @vram_base:	Base address of the managed video memory
172  * @vram_size:	Size of the managed video memory in bytes
173  * @bdev:	The TTM BO device.
174  * @funcs:	TTM BO functions
175  *
176  * The fields &struct drm_vram_mm.vram_base and
177  * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are
178  * available for public read access. Use the field
179  * &struct drm_vram_mm.bdev to access the TTM BO device.
180  */
181 struct drm_vram_mm {
182 	uint64_t vram_base;
183 	size_t vram_size;
184 
185 	struct ttm_bo_device bdev;
186 };
187 
188 /**
189  * drm_vram_mm_of_bdev() - \
190 	Returns the container of type &struct ttm_bo_device for field bdev.
191  * @bdev:	the TTM BO device
192  *
193  * Returns:
194  * The containing instance of &struct drm_vram_mm
195  */
196 static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
197 	struct ttm_bo_device *bdev)
198 {
199 	return container_of(bdev, struct drm_vram_mm, bdev);
200 }
201 
202 int drm_vram_mm_debugfs_init(struct drm_minor *minor);
203 
204 /*
205  * Helpers for integration with struct drm_device
206  */
207 
208 struct drm_vram_mm *drm_vram_helper_alloc_mm(
209 	struct drm_device *dev, uint64_t vram_base, size_t vram_size);
210 void drm_vram_helper_release_mm(struct drm_device *dev);
211 
212 #endif
213