xref: /openbmc/linux/include/drm/drm_gem.h (revision 6d99a79c)
1 #ifndef __DRM_GEM_H__
2 #define __DRM_GEM_H__
3 
4 /*
5  * GEM Graphics Execution Manager Driver Interfaces
6  *
7  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
8  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
9  * Copyright (c) 2009-2010, Code Aurora Forum.
10  * All rights reserved.
11  * Copyright © 2014 Intel Corporation
12  *   Daniel Vetter <daniel.vetter@ffwll.ch>
13  *
14  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
15  * Author: Gareth Hughes <gareth@valinux.com>
16  *
17  * Permission is hereby granted, free of charge, to any person obtaining a
18  * copy of this software and associated documentation files (the "Software"),
19  * to deal in the Software without restriction, including without limitation
20  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
21  * and/or sell copies of the Software, and to permit persons to whom the
22  * Software is furnished to do so, subject to the following conditions:
23  *
24  * The above copyright notice and this permission notice (including the next
25  * paragraph) shall be included in all copies or substantial portions of the
26  * Software.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
29  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
30  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
31  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
32  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
33  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
34  * OTHER DEALINGS IN THE SOFTWARE.
35  */
36 
37 #include <linux/kref.h>
38 
39 #include <drm/drm_vma_manager.h>
40 
41 /**
42  * struct drm_gem_object - GEM buffer object
43  *
44  * This structure defines the generic parts for GEM buffer objects, which are
45  * mostly around handling mmap and userspace handles.
46  *
47  * Buffer objects are often abbreviated to BO.
48  */
49 struct drm_gem_object {
50 	/**
51 	 * @refcount:
52 	 *
53 	 * Reference count of this object
54 	 *
55 	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put()
56 	 * or drm_gem_object_put_unlocked() to release a reference to a GEM
57 	 * buffer object.
58 	 */
59 	struct kref refcount;
60 
61 	/**
62 	 * @handle_count:
63 	 *
64 	 * This is the GEM file_priv handle count of this object.
65 	 *
66 	 * Each handle also holds a reference. Note that when the handle_count
67 	 * drops to 0 any global names (e.g. the id in the flink namespace) will
68 	 * be cleared.
69 	 *
70 	 * Protected by &drm_device.object_name_lock.
71 	 */
72 	unsigned handle_count;
73 
74 	/**
75 	 * @dev: DRM dev this object belongs to.
76 	 */
77 	struct drm_device *dev;
78 
79 	/**
80 	 * @filp:
81 	 *
82 	 * SHMEM file node used as backing storage for swappable buffer objects.
83 	 * GEM also supports driver private objects with driver-specific backing
84 	 * storage (contiguous CMA memory, special reserved blocks). In this
85 	 * case @filp is NULL.
86 	 */
87 	struct file *filp;
88 
89 	/**
90 	 * @vma_node:
91 	 *
92 	 * Mapping info for this object to support mmap. Drivers are supposed to
93 	 * allocate the mmap offset using drm_gem_create_mmap_offset(). The
94 	 * offset itself can be retrieved using drm_vma_node_offset_addr().
95 	 *
96 	 * Memory mapping itself is handled by drm_gem_mmap(), which also checks
97 	 * that userspace is allowed to access the object.
98 	 */
99 	struct drm_vma_offset_node vma_node;
100 
101 	/**
102 	 * @size:
103 	 *
104 	 * Size of the object, in bytes.  Immutable over the object's
105 	 * lifetime.
106 	 */
107 	size_t size;
108 
109 	/**
110 	 * @name:
111 	 *
112 	 * Global name for this object, starts at 1. 0 means unnamed.
113 	 * Access is covered by &drm_device.object_name_lock. This is used by
114 	 * the GEM_FLINK and GEM_OPEN ioctls.
115 	 */
116 	int name;
117 
118 	/**
119 	 * @dma_buf:
120 	 *
121 	 * dma-buf associated with this GEM object.
122 	 *
123 	 * Pointer to the dma-buf associated with this gem object (either
124 	 * through importing or exporting). We break the resulting reference
125 	 * loop when the last gem handle for this object is released.
126 	 *
127 	 * Protected by &drm_device.object_name_lock.
128 	 */
129 	struct dma_buf *dma_buf;
130 
131 	/**
132 	 * @import_attach:
133 	 *
134 	 * dma-buf attachment backing this object.
135 	 *
136 	 * Any foreign dma_buf imported as a gem object has this set to the
137 	 * attachment point for the device. This is invariant over the lifetime
138 	 * of a gem object.
139 	 *
140 	 * The &drm_driver.gem_free_object callback is responsible for cleaning
141 	 * up the dma_buf attachment and references acquired at import time.
142 	 *
143 	 * Note that the drm gem/prime core does not depend upon drivers setting
144 	 * this field any more. So for drivers where this doesn't make sense
145 	 * (e.g. virtual devices or a displaylink behind an usb bus) they can
146 	 * simply leave it as NULL.
147 	 */
148 	struct dma_buf_attachment *import_attach;
149 };
150 
151 /**
152  * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
153  * @name: name for the generated structure
154  *
155  * This macro autogenerates a suitable &struct file_operations for GEM based
156  * drivers, which can be assigned to &drm_driver.fops. Note that this structure
157  * cannot be shared between drivers, because it contains a reference to the
158  * current module using THIS_MODULE.
159  *
160  * Note that the declaration is already marked as static - if you need a
161  * non-static version of this you're probably doing it wrong and will break the
162  * THIS_MODULE reference by accident.
163  */
164 #define DEFINE_DRM_GEM_FOPS(name) \
165 	static const struct file_operations name = {\
166 		.owner		= THIS_MODULE,\
167 		.open		= drm_open,\
168 		.release	= drm_release,\
169 		.unlocked_ioctl	= drm_ioctl,\
170 		.compat_ioctl	= drm_compat_ioctl,\
171 		.poll		= drm_poll,\
172 		.read		= drm_read,\
173 		.llseek		= noop_llseek,\
174 		.mmap		= drm_gem_mmap,\
175 	}
176 
177 void drm_gem_object_release(struct drm_gem_object *obj);
178 void drm_gem_object_free(struct kref *kref);
179 int drm_gem_object_init(struct drm_device *dev,
180 			struct drm_gem_object *obj, size_t size);
181 void drm_gem_private_object_init(struct drm_device *dev,
182 				 struct drm_gem_object *obj, size_t size);
183 void drm_gem_vm_open(struct vm_area_struct *vma);
184 void drm_gem_vm_close(struct vm_area_struct *vma);
185 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
186 		     struct vm_area_struct *vma);
187 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
188 
189 /**
190  * drm_gem_object_get - acquire a GEM buffer object reference
191  * @obj: GEM buffer object
192  *
193  * This function acquires an additional reference to @obj. It is illegal to
194  * call this without already holding a reference. No locks required.
195  */
196 static inline void drm_gem_object_get(struct drm_gem_object *obj)
197 {
198 	kref_get(&obj->refcount);
199 }
200 
201 /**
202  * __drm_gem_object_put - raw function to release a GEM buffer object reference
203  * @obj: GEM buffer object
204  *
205  * This function is meant to be used by drivers which are not encumbered with
206  * &drm_device.struct_mutex legacy locking and which are using the
207  * gem_free_object_unlocked callback. It avoids all the locking checks and
208  * locking overhead of drm_gem_object_put() and drm_gem_object_put_unlocked().
209  *
210  * Drivers should never call this directly in their code. Instead they should
211  * wrap it up into a ``driver_gem_object_put(struct driver_gem_object *obj)``
212  * wrapper function, and use that. Shared code should never call this, to
213  * avoid breaking drivers by accident which still depend upon
214  * &drm_device.struct_mutex locking.
215  */
216 static inline void
217 __drm_gem_object_put(struct drm_gem_object *obj)
218 {
219 	kref_put(&obj->refcount, drm_gem_object_free);
220 }
221 
222 void drm_gem_object_put_unlocked(struct drm_gem_object *obj);
223 void drm_gem_object_put(struct drm_gem_object *obj);
224 
225 /**
226  * drm_gem_object_reference - acquire a GEM buffer object reference
227  * @obj: GEM buffer object
228  *
229  * This is a compatibility alias for drm_gem_object_get() and should not be
230  * used by new code.
231  */
232 static inline void drm_gem_object_reference(struct drm_gem_object *obj)
233 {
234 	drm_gem_object_get(obj);
235 }
236 
237 /**
238  * __drm_gem_object_unreference - raw function to release a GEM buffer object
239  *                                reference
240  * @obj: GEM buffer object
241  *
242  * This is a compatibility alias for __drm_gem_object_put() and should not be
243  * used by new code.
244  */
245 static inline void __drm_gem_object_unreference(struct drm_gem_object *obj)
246 {
247 	__drm_gem_object_put(obj);
248 }
249 
250 /**
251  * drm_gem_object_unreference_unlocked - release a GEM buffer object reference
252  * @obj: GEM buffer object
253  *
254  * This is a compatibility alias for drm_gem_object_put_unlocked() and should
255  * not be used by new code.
256  */
257 static inline void
258 drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
259 {
260 	drm_gem_object_put_unlocked(obj);
261 }
262 
263 /**
264  * drm_gem_object_unreference - release a GEM buffer object reference
265  * @obj: GEM buffer object
266  *
267  * This is a compatibility alias for drm_gem_object_put() and should not be
268  * used by new code.
269  */
270 static inline void drm_gem_object_unreference(struct drm_gem_object *obj)
271 {
272 	drm_gem_object_put(obj);
273 }
274 
275 int drm_gem_handle_create(struct drm_file *file_priv,
276 			  struct drm_gem_object *obj,
277 			  u32 *handlep);
278 int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
279 
280 
281 void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
282 int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
283 int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
284 
285 struct page **drm_gem_get_pages(struct drm_gem_object *obj);
286 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
287 		bool dirty, bool accessed);
288 
289 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
290 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
291 			    u32 handle, u64 *offset);
292 int drm_gem_dumb_destroy(struct drm_file *file,
293 			 struct drm_device *dev,
294 			 uint32_t handle);
295 
296 #endif /* __DRM_GEM_H__ */
297