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,
117 		       struct iosys_map *map);
118 void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
119 			  struct iosys_map *map);
120 int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct *vma);
121 
122 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
123 
124 static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
125 {
126 	return (shmem->madv > 0) &&
127 		!shmem->vmap_use_count && shmem->sgt &&
128 		!shmem->base.dma_buf && !shmem->base.import_attach;
129 }
130 
131 void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem);
132 bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
133 
134 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem);
135 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem);
136 
137 void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
138 			      struct drm_printer *p, unsigned int indent);
139 
140 /*
141  * GEM object functions
142  */
143 
144 /**
145  * drm_gem_shmem_object_free - GEM object function for drm_gem_shmem_free()
146  * @obj: GEM object to free
147  *
148  * This function wraps drm_gem_shmem_free(). Drivers that employ the shmem helpers
149  * should use it as their &drm_gem_object_funcs.free handler.
150  */
151 static inline void drm_gem_shmem_object_free(struct drm_gem_object *obj)
152 {
153 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
154 
155 	drm_gem_shmem_free(shmem);
156 }
157 
158 /**
159  * drm_gem_shmem_object_print_info() - Print &drm_gem_shmem_object info for debugfs
160  * @p: DRM printer
161  * @indent: Tab indentation level
162  * @obj: GEM object
163  *
164  * This function wraps drm_gem_shmem_print_info(). Drivers that employ the shmem helpers should
165  * use this function as their &drm_gem_object_funcs.print_info handler.
166  */
167 static inline void drm_gem_shmem_object_print_info(struct drm_printer *p, unsigned int indent,
168 						   const struct drm_gem_object *obj)
169 {
170 	const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
171 
172 	drm_gem_shmem_print_info(shmem, p, indent);
173 }
174 
175 /**
176  * drm_gem_shmem_object_pin - GEM object function for drm_gem_shmem_pin()
177  * @obj: GEM object
178  *
179  * This function wraps drm_gem_shmem_pin(). Drivers that employ the shmem helpers should
180  * use it as their &drm_gem_object_funcs.pin handler.
181  */
182 static inline int drm_gem_shmem_object_pin(struct drm_gem_object *obj)
183 {
184 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
185 
186 	return drm_gem_shmem_pin(shmem);
187 }
188 
189 /**
190  * drm_gem_shmem_object_unpin - GEM object function for drm_gem_shmem_unpin()
191  * @obj: GEM object
192  *
193  * This function wraps drm_gem_shmem_unpin(). Drivers that employ the shmem helpers should
194  * use it as their &drm_gem_object_funcs.unpin handler.
195  */
196 static inline void drm_gem_shmem_object_unpin(struct drm_gem_object *obj)
197 {
198 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
199 
200 	drm_gem_shmem_unpin(shmem);
201 }
202 
203 /**
204  * drm_gem_shmem_object_get_sg_table - GEM object function for drm_gem_shmem_get_sg_table()
205  * @obj: GEM object
206  *
207  * This function wraps drm_gem_shmem_get_sg_table(). Drivers that employ the shmem helpers should
208  * use it as their &drm_gem_object_funcs.get_sg_table handler.
209  *
210  * Returns:
211  * A pointer to the scatter/gather table of pinned pages or NULL on failure.
212  */
213 static inline struct sg_table *drm_gem_shmem_object_get_sg_table(struct drm_gem_object *obj)
214 {
215 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
216 
217 	return drm_gem_shmem_get_sg_table(shmem);
218 }
219 
220 /*
221  * drm_gem_shmem_object_vmap - GEM object function for drm_gem_shmem_vmap()
222  * @obj: GEM object
223  * @map: Returns the kernel virtual address of the SHMEM GEM object's backing store.
224  *
225  * This function wraps drm_gem_shmem_vmap(). Drivers that employ the shmem helpers should
226  * use it as their &drm_gem_object_funcs.vmap handler.
227  *
228  * Returns:
229  * 0 on success or a negative error code on failure.
230  */
231 static inline int drm_gem_shmem_object_vmap(struct drm_gem_object *obj,
232 					    struct iosys_map *map)
233 {
234 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
235 
236 	return drm_gem_shmem_vmap(shmem, map);
237 }
238 
239 /*
240  * drm_gem_shmem_object_vunmap - GEM object function for drm_gem_shmem_vunmap()
241  * @obj: GEM object
242  * @map: Kernel virtual address where the SHMEM GEM object was mapped
243  *
244  * This function wraps drm_gem_shmem_vunmap(). Drivers that employ the shmem helpers should
245  * use it as their &drm_gem_object_funcs.vunmap handler.
246  */
247 static inline void drm_gem_shmem_object_vunmap(struct drm_gem_object *obj,
248 					       struct iosys_map *map)
249 {
250 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
251 
252 	drm_gem_shmem_vunmap(shmem, map);
253 }
254 
255 /**
256  * drm_gem_shmem_object_mmap - GEM object function for drm_gem_shmem_mmap()
257  * @obj: GEM object
258  * @vma: VMA for the area to be mapped
259  *
260  * This function wraps drm_gem_shmem_mmap(). Drivers that employ the shmem helpers should
261  * use it as their &drm_gem_object_funcs.mmap handler.
262  *
263  * Returns:
264  * 0 on success or a negative error code on failure.
265  */
266 static inline int drm_gem_shmem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
267 {
268 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
269 
270 	return drm_gem_shmem_mmap(shmem, vma);
271 }
272 
273 /*
274  * Driver ops
275  */
276 
277 struct drm_gem_object *
278 drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
279 				    struct dma_buf_attachment *attach,
280 				    struct sg_table *sgt);
281 int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
282 			      struct drm_mode_create_dumb *args);
283 
284 /**
285  * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations
286  *
287  * This macro provides a shortcut for setting the shmem GEM operations in
288  * the &drm_driver structure.
289  */
290 #define DRM_GEM_SHMEM_DRIVER_OPS \
291 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd, \
292 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle, \
293 	.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \
294 	.gem_prime_mmap		= drm_gem_prime_mmap, \
295 	.dumb_create		= drm_gem_shmem_dumb_create
296 
297 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */
298