xref: /linux/include/drm/drm_gem.h (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
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 /**
38  * struct drm_gem_object - GEM buffer object
39  *
40  * This structure defines the generic parts for GEM buffer objects, which are
41  * mostly around handling mmap and userspace handles.
42  *
43  * Buffer objects are often abbreviated to BO.
44  */
45 struct drm_gem_object {
46 	/**
47 	 * @refcount:
48 	 *
49 	 * Reference count of this object
50 	 *
51 	 * Please use drm_gem_object_reference() to acquire and
52 	 * drm_gem_object_unreference() or drm_gem_object_unreference_unlocked()
53 	 * to release a reference to a GEM buffer object.
54 	 */
55 	struct kref refcount;
56 
57 	/**
58 	 * @handle_count:
59 	 *
60 	 * This is the GEM file_priv handle count of this object.
61 	 *
62 	 * Each handle also holds a reference. Note that when the handle_count
63 	 * drops to 0 any global names (e.g. the id in the flink namespace) will
64 	 * be cleared.
65 	 *
66 	 * Protected by dev->object_name_lock.
67 	 */
68 	unsigned handle_count;
69 
70 	/**
71 	 * @dev: DRM dev this object belongs to.
72 	 */
73 	struct drm_device *dev;
74 
75 	/**
76 	 * @filp:
77 	 *
78 	 * SHMEM file node used as backing storage for swappable buffer objects.
79 	 * GEM also supports driver private objects with driver-specific backing
80 	 * storage (contiguous CMA memory, special reserved blocks). In this
81 	 * case @filp is NULL.
82 	 */
83 	struct file *filp;
84 
85 	/**
86 	 * @vma_node:
87 	 *
88 	 * Mapping info for this object to support mmap. Drivers are supposed to
89 	 * allocate the mmap offset using drm_gem_create_mmap_offset(). The
90 	 * offset itself can be retrieved using drm_vma_node_offset_addr().
91 	 *
92 	 * Memory mapping itself is handled by drm_gem_mmap(), which also checks
93 	 * that userspace is allowed to access the object.
94 	 */
95 	struct drm_vma_offset_node vma_node;
96 
97 	/**
98 	 * @size:
99 	 *
100 	 * Size of the object, in bytes.  Immutable over the object's
101 	 * lifetime.
102 	 */
103 	size_t size;
104 
105 	/**
106 	 * @name:
107 	 *
108 	 * Global name for this object, starts at 1. 0 means unnamed.
109 	 * Access is covered by dev->object_name_lock. This is used by the GEM_FLINK
110 	 * and GEM_OPEN ioctls.
111 	 */
112 	int name;
113 
114 	/**
115 	 * @read_domains:
116 	 *
117 	 * Read memory domains. These monitor which caches contain read/write data
118 	 * related to the object. When transitioning from one set of domains
119 	 * to another, the driver is called to ensure that caches are suitably
120 	 * flushed and invalidated.
121 	 */
122 	uint32_t read_domains;
123 
124 	/**
125 	 * @write_domain: Corresponding unique write memory domain.
126 	 */
127 	uint32_t write_domain;
128 
129 	/**
130 	 * @pending_read_domains:
131 	 *
132 	 * While validating an exec operation, the
133 	 * new read/write domain values are computed here.
134 	 * They will be transferred to the above values
135 	 * at the point that any cache flushing occurs
136 	 */
137 	uint32_t pending_read_domains;
138 
139 	/**
140 	 * @pending_write_domain: Write domain similar to @pending_read_domains.
141 	 */
142 	uint32_t pending_write_domain;
143 
144 	/**
145 	 * @dma_buf:
146 	 *
147 	 * dma-buf associated with this GEM object.
148 	 *
149 	 * Pointer to the dma-buf associated with this gem object (either
150 	 * through importing or exporting). We break the resulting reference
151 	 * loop when the last gem handle for this object is released.
152 	 *
153 	 * Protected by obj->object_name_lock.
154 	 */
155 	struct dma_buf *dma_buf;
156 
157 	/**
158 	 * @import_attach:
159 	 *
160 	 * dma-buf attachment backing this object.
161 	 *
162 	 * Any foreign dma_buf imported as a gem object has this set to the
163 	 * attachment point for the device. This is invariant over the lifetime
164 	 * of a gem object.
165 	 *
166 	 * The driver's ->gem_free_object callback is responsible for cleaning
167 	 * up the dma_buf attachment and references acquired at import time.
168 	 *
169 	 * Note that the drm gem/prime core does not depend upon drivers setting
170 	 * this field any more. So for drivers where this doesn't make sense
171 	 * (e.g. virtual devices or a displaylink behind an usb bus) they can
172 	 * simply leave it as NULL.
173 	 */
174 	struct dma_buf_attachment *import_attach;
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_reference - acquire a GEM BO reference
191  * @obj: GEM buffer object
192  *
193  * This acquires additional reference to @obj. It is illegal to call this
194  * without already holding a reference. No locks required.
195  */
196 static inline void
197 drm_gem_object_reference(struct drm_gem_object *obj)
198 {
199 	kref_get(&obj->refcount);
200 }
201 
202 /**
203  * drm_gem_object_unreference - release a GEM BO reference
204  * @obj: GEM buffer object
205  *
206  * This releases a reference to @obj. Callers must hold the dev->struct_mutex
207  * lock when calling this function, even when the driver doesn't use
208  * dev->struct_mutex for anything.
209  *
210  * For drivers not encumbered with legacy locking use
211  * drm_gem_object_unreference_unlocked() instead.
212  */
213 static inline void
214 drm_gem_object_unreference(struct drm_gem_object *obj)
215 {
216 	if (obj != NULL) {
217 		WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
218 
219 		kref_put(&obj->refcount, drm_gem_object_free);
220 	}
221 }
222 
223 /**
224  * drm_gem_object_unreference_unlocked - release a GEM BO reference
225  * @obj: GEM buffer object
226  *
227  * This releases a reference to @obj. Callers must not hold the
228  * dev->struct_mutex lock when calling this function.
229  */
230 static inline void
231 drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
232 {
233 	struct drm_device *dev;
234 
235 	if (!obj)
236 		return;
237 
238 	dev = obj->dev;
239 	if (kref_put_mutex(&obj->refcount, drm_gem_object_free, &dev->struct_mutex))
240 		mutex_unlock(&dev->struct_mutex);
241 	else
242 		might_lock(&dev->struct_mutex);
243 }
244 
245 int drm_gem_handle_create(struct drm_file *file_priv,
246 			  struct drm_gem_object *obj,
247 			  u32 *handlep);
248 int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
249 
250 
251 void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
252 int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
253 int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
254 
255 struct page **drm_gem_get_pages(struct drm_gem_object *obj);
256 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
257 		bool dirty, bool accessed);
258 
259 struct drm_gem_object *drm_gem_object_lookup(struct drm_device *dev,
260 					     struct drm_file *filp,
261 					     u32 handle);
262 int drm_gem_dumb_destroy(struct drm_file *file,
263 			 struct drm_device *dev,
264 			 uint32_t handle);
265 
266 #endif /* __DRM_GEM_H__ */
267