1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef __DRM_GEM_SHMEM_HELPER_H__
4 #define __DRM_GEM_SHMEM_HELPER_H__
5 
6 #include <linux/fs.h>
7 #include <linux/mm.h>
8 #include <linux/mutex.h>
9 
10 #include <drm/drm_file.h>
11 #include <drm/drm_gem.h>
12 #include <drm/drm_ioctl.h>
13 #include <drm/drm_prime.h>
14 
15 struct dma_buf_attachment;
16 struct drm_mode_create_dumb;
17 struct drm_printer;
18 struct sg_table;
19 
20 /**
21  * struct drm_gem_shmem_object - GEM object backed by shmem
22  */
23 struct drm_gem_shmem_object {
24 	/**
25 	 * @base: Base GEM object
26 	 */
27 	struct drm_gem_object base;
28 
29 	/**
30 	 * @pages_lock: Protects the page table and use count
31 	 */
32 	struct mutex pages_lock;
33 
34 	/**
35 	 * @pages: Page table
36 	 */
37 	struct page **pages;
38 
39 	/**
40 	 * @pages_use_count:
41 	 *
42 	 * Reference count on the pages table.
43 	 * The pages are put when the count reaches zero.
44 	 */
45 	unsigned int pages_use_count;
46 
47 	/**
48 	 * @madv: State for madvise
49 	 *
50 	 * 0 is active/inuse.
51 	 * A negative value is the object is purged.
52 	 * Positive values are driver specific and not used by the helpers.
53 	 */
54 	int madv;
55 
56 	/**
57 	 * @madv_list: List entry for madvise tracking
58 	 *
59 	 * Typically used by drivers to track purgeable objects
60 	 */
61 	struct list_head madv_list;
62 
63 	/**
64 	 * @pages_mark_dirty_on_put:
65 	 *
66 	 * Mark pages as dirty when they are put.
67 	 */
68 	unsigned int pages_mark_dirty_on_put    : 1;
69 
70 	/**
71 	 * @pages_mark_accessed_on_put:
72 	 *
73 	 * Mark pages as accessed when they are put.
74 	 */
75 	unsigned int pages_mark_accessed_on_put : 1;
76 
77 	/**
78 	 * @sgt: Scatter/gather table for imported PRIME buffers
79 	 */
80 	struct sg_table *sgt;
81 
82 	/**
83 	 * @vmap_lock: Protects the vmap address and use count
84 	 */
85 	struct mutex vmap_lock;
86 
87 	/**
88 	 * @vaddr: Kernel virtual address of the backing memory
89 	 */
90 	void *vaddr;
91 
92 	/**
93 	 * @vmap_use_count:
94 	 *
95 	 * Reference count on the virtual address.
96 	 * The address are un-mapped when the count reaches zero.
97 	 */
98 	unsigned int vmap_use_count;
99 
100 	/**
101 	 * @map_wc: map object write-combined (instead of using shmem defaults).
102 	 */
103 	bool map_wc;
104 };
105 
106 #define to_drm_gem_shmem_obj(obj) \
107 	container_of(obj, struct drm_gem_shmem_object, base)
108 
109 struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
110 void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem);
111 
112 int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
113 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
114 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem);
115 void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem);
116 int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map);
117 void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map);
118 int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct *vma);
119 
120 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
121 
122 static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
123 {
124 	return (shmem->madv > 0) &&
125 		!shmem->vmap_use_count && shmem->sgt &&
126 		!shmem->base.dma_buf && !shmem->base.import_attach;
127 }
128 
129 void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem);
130 bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
131 
132 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem);
133 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem);
134 
135 void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
136 			      struct drm_printer *p, unsigned int indent);
137 
138 /*
139  * GEM object functions
140  */
141 
142 /**
143  * drm_gem_shmem_object_free - GEM object function for drm_gem_shmem_free()
144  * @obj: GEM object to free
145  *
146  * This function wraps drm_gem_shmem_free(). Drivers that employ the shmem helpers
147  * should use it as their &drm_gem_object_funcs.free handler.
148  */
149 static inline void drm_gem_shmem_object_free(struct drm_gem_object *obj)
150 {
151 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
152 
153 	drm_gem_shmem_free(shmem);
154 }
155 
156 /**
157  * drm_gem_shmem_object_print_info() - Print &drm_gem_shmem_object info for debugfs
158  * @p: DRM printer
159  * @indent: Tab indentation level
160  * @obj: GEM object
161  *
162  * This function wraps drm_gem_shmem_print_info(). Drivers that employ the shmem helpers should
163  * use this function as their &drm_gem_object_funcs.print_info handler.
164  */
165 static inline void drm_gem_shmem_object_print_info(struct drm_printer *p, unsigned int indent,
166 						   const struct drm_gem_object *obj)
167 {
168 	const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
169 
170 	drm_gem_shmem_print_info(shmem, p, indent);
171 }
172 
173 /**
174  * drm_gem_shmem_object_pin - GEM object function for drm_gem_shmem_pin()
175  * @obj: GEM object
176  *
177  * This function wraps drm_gem_shmem_pin(). Drivers that employ the shmem helpers should
178  * use it as their &drm_gem_object_funcs.pin handler.
179  */
180 static inline int drm_gem_shmem_object_pin(struct drm_gem_object *obj)
181 {
182 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
183 
184 	return drm_gem_shmem_pin(shmem);
185 }
186 
187 /**
188  * drm_gem_shmem_object_unpin - GEM object function for drm_gem_shmem_unpin()
189  * @obj: GEM object
190  *
191  * This function wraps drm_gem_shmem_unpin(). Drivers that employ the shmem helpers should
192  * use it as their &drm_gem_object_funcs.unpin handler.
193  */
194 static inline void drm_gem_shmem_object_unpin(struct drm_gem_object *obj)
195 {
196 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
197 
198 	drm_gem_shmem_unpin(shmem);
199 }
200 
201 /**
202  * drm_gem_shmem_object_get_sg_table - GEM object function for drm_gem_shmem_get_sg_table()
203  * @obj: GEM object
204  *
205  * This function wraps drm_gem_shmem_get_sg_table(). Drivers that employ the shmem helpers should
206  * use it as their &drm_gem_object_funcs.get_sg_table handler.
207  *
208  * Returns:
209  * A pointer to the scatter/gather table of pinned pages or NULL on failure.
210  */
211 static inline struct sg_table *drm_gem_shmem_object_get_sg_table(struct drm_gem_object *obj)
212 {
213 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
214 
215 	return drm_gem_shmem_get_sg_table(shmem);
216 }
217 
218 /*
219  * drm_gem_shmem_object_vmap - GEM object function for drm_gem_shmem_vmap()
220  * @obj: GEM object
221  * @map: Returns the kernel virtual address of the SHMEM GEM object's backing store.
222  *
223  * This function wraps drm_gem_shmem_vmap(). Drivers that employ the shmem helpers should
224  * use it as their &drm_gem_object_funcs.vmap handler.
225  *
226  * Returns:
227  * 0 on success or a negative error code on failure.
228  */
229 static inline int drm_gem_shmem_object_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
230 {
231 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
232 
233 	return drm_gem_shmem_vmap(shmem, map);
234 }
235 
236 /*
237  * drm_gem_shmem_object_vunmap - GEM object function for drm_gem_shmem_vunmap()
238  * @obj: GEM object
239  * @map: Kernel virtual address where the SHMEM GEM object was mapped
240  *
241  * This function wraps drm_gem_shmem_vunmap(). Drivers that employ the shmem helpers should
242  * use it as their &drm_gem_object_funcs.vunmap handler.
243  */
244 static inline void drm_gem_shmem_object_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
245 {
246 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
247 
248 	drm_gem_shmem_vunmap(shmem, map);
249 }
250 
251 /**
252  * drm_gem_shmem_object_mmap - GEM object function for drm_gem_shmem_mmap()
253  * @obj: GEM object
254  * @vma: VMA for the area to be mapped
255  *
256  * This function wraps drm_gem_shmem_mmap(). Drivers that employ the shmem helpers should
257  * use it as their &drm_gem_object_funcs.mmap handler.
258  *
259  * Returns:
260  * 0 on success or a negative error code on failure.
261  */
262 static inline int drm_gem_shmem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
263 {
264 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
265 
266 	return drm_gem_shmem_mmap(shmem, vma);
267 }
268 
269 /*
270  * Driver ops
271  */
272 
273 struct drm_gem_object *
274 drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
275 				    struct dma_buf_attachment *attach,
276 				    struct sg_table *sgt);
277 int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
278 			      struct drm_mode_create_dumb *args);
279 
280 /**
281  * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations
282  *
283  * This macro provides a shortcut for setting the shmem GEM operations in
284  * the &drm_driver structure.
285  */
286 #define DRM_GEM_SHMEM_DRIVER_OPS \
287 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd, \
288 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle, \
289 	.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \
290 	.gem_prime_mmap		= drm_gem_prime_mmap, \
291 	.dumb_create		= drm_gem_shmem_dumb_create
292 
293 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */
294