xref: /openbmc/linux/include/drm/drm_gem.h (revision dea54fba)
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 	 * @read_domains:
120 	 *
121 	 * Read memory domains. These monitor which caches contain read/write data
122 	 * related to the object. When transitioning from one set of domains
123 	 * to another, the driver is called to ensure that caches are suitably
124 	 * flushed and invalidated.
125 	 */
126 	uint32_t read_domains;
127 
128 	/**
129 	 * @write_domain: Corresponding unique write memory domain.
130 	 */
131 	uint32_t write_domain;
132 
133 	/**
134 	 * @pending_read_domains:
135 	 *
136 	 * While validating an exec operation, the
137 	 * new read/write domain values are computed here.
138 	 * They will be transferred to the above values
139 	 * at the point that any cache flushing occurs
140 	 */
141 	uint32_t pending_read_domains;
142 
143 	/**
144 	 * @pending_write_domain: Write domain similar to @pending_read_domains.
145 	 */
146 	uint32_t pending_write_domain;
147 
148 	/**
149 	 * @dma_buf:
150 	 *
151 	 * dma-buf associated with this GEM object.
152 	 *
153 	 * Pointer to the dma-buf associated with this gem object (either
154 	 * through importing or exporting). We break the resulting reference
155 	 * loop when the last gem handle for this object is released.
156 	 *
157 	 * Protected by &drm_device.object_name_lock.
158 	 */
159 	struct dma_buf *dma_buf;
160 
161 	/**
162 	 * @import_attach:
163 	 *
164 	 * dma-buf attachment backing this object.
165 	 *
166 	 * Any foreign dma_buf imported as a gem object has this set to the
167 	 * attachment point for the device. This is invariant over the lifetime
168 	 * of a gem object.
169 	 *
170 	 * The &drm_driver.gem_free_object callback is responsible for cleaning
171 	 * up the dma_buf attachment and references acquired at import time.
172 	 *
173 	 * Note that the drm gem/prime core does not depend upon drivers setting
174 	 * this field any more. So for drivers where this doesn't make sense
175 	 * (e.g. virtual devices or a displaylink behind an usb bus) they can
176 	 * simply leave it as NULL.
177 	 */
178 	struct dma_buf_attachment *import_attach;
179 };
180 
181 /**
182  * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
183  * @name: name for the generated structure
184  *
185  * This macro autogenerates a suitable &struct file_operations for GEM based
186  * drivers, which can be assigned to &drm_driver.fops. Note that this structure
187  * cannot be shared between drivers, because it contains a reference to the
188  * current module using THIS_MODULE.
189  *
190  * Note that the declaration is already marked as static - if you need a
191  * non-static version of this you're probably doing it wrong and will break the
192  * THIS_MODULE reference by accident.
193  */
194 #define DEFINE_DRM_GEM_FOPS(name) \
195 	static const struct file_operations name = {\
196 		.owner		= THIS_MODULE,\
197 		.open		= drm_open,\
198 		.release	= drm_release,\
199 		.unlocked_ioctl	= drm_ioctl,\
200 		.compat_ioctl	= drm_compat_ioctl,\
201 		.poll		= drm_poll,\
202 		.read		= drm_read,\
203 		.llseek		= noop_llseek,\
204 		.mmap		= drm_gem_mmap,\
205 	}
206 
207 void drm_gem_object_release(struct drm_gem_object *obj);
208 void drm_gem_object_free(struct kref *kref);
209 int drm_gem_object_init(struct drm_device *dev,
210 			struct drm_gem_object *obj, size_t size);
211 void drm_gem_private_object_init(struct drm_device *dev,
212 				 struct drm_gem_object *obj, size_t size);
213 void drm_gem_vm_open(struct vm_area_struct *vma);
214 void drm_gem_vm_close(struct vm_area_struct *vma);
215 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
216 		     struct vm_area_struct *vma);
217 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
218 
219 /**
220  * drm_gem_object_get - acquire a GEM buffer object reference
221  * @obj: GEM buffer object
222  *
223  * This function acquires an additional reference to @obj. It is illegal to
224  * call this without already holding a reference. No locks required.
225  */
226 static inline void drm_gem_object_get(struct drm_gem_object *obj)
227 {
228 	kref_get(&obj->refcount);
229 }
230 
231 /**
232  * __drm_gem_object_put - raw function to release a GEM buffer object reference
233  * @obj: GEM buffer object
234  *
235  * This function is meant to be used by drivers which are not encumbered with
236  * &drm_device.struct_mutex legacy locking and which are using the
237  * gem_free_object_unlocked callback. It avoids all the locking checks and
238  * locking overhead of drm_gem_object_put() and drm_gem_object_put_unlocked().
239  *
240  * Drivers should never call this directly in their code. Instead they should
241  * wrap it up into a ``driver_gem_object_put(struct driver_gem_object *obj)``
242  * wrapper function, and use that. Shared code should never call this, to
243  * avoid breaking drivers by accident which still depend upon
244  * &drm_device.struct_mutex locking.
245  */
246 static inline void
247 __drm_gem_object_put(struct drm_gem_object *obj)
248 {
249 	kref_put(&obj->refcount, drm_gem_object_free);
250 }
251 
252 void drm_gem_object_put_unlocked(struct drm_gem_object *obj);
253 void drm_gem_object_put(struct drm_gem_object *obj);
254 
255 /**
256  * drm_gem_object_reference - acquire a GEM buffer object reference
257  * @obj: GEM buffer object
258  *
259  * This is a compatibility alias for drm_gem_object_get() and should not be
260  * used by new code.
261  */
262 static inline void drm_gem_object_reference(struct drm_gem_object *obj)
263 {
264 	drm_gem_object_get(obj);
265 }
266 
267 /**
268  * __drm_gem_object_unreference - raw function to release a GEM buffer object
269  *                                reference
270  * @obj: GEM buffer object
271  *
272  * This is a compatibility alias for __drm_gem_object_put() and should not be
273  * used by new code.
274  */
275 static inline void __drm_gem_object_unreference(struct drm_gem_object *obj)
276 {
277 	__drm_gem_object_put(obj);
278 }
279 
280 /**
281  * drm_gem_object_unreference_unlocked - release a GEM buffer object reference
282  * @obj: GEM buffer object
283  *
284  * This is a compatibility alias for drm_gem_object_put_unlocked() and should
285  * not be used by new code.
286  */
287 static inline void
288 drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
289 {
290 	drm_gem_object_put_unlocked(obj);
291 }
292 
293 /**
294  * drm_gem_object_unreference - release a GEM buffer object reference
295  * @obj: GEM buffer object
296  *
297  * This is a compatibility alias for drm_gem_object_put() and should not be
298  * used by new code.
299  */
300 static inline void drm_gem_object_unreference(struct drm_gem_object *obj)
301 {
302 	drm_gem_object_put(obj);
303 }
304 
305 int drm_gem_handle_create(struct drm_file *file_priv,
306 			  struct drm_gem_object *obj,
307 			  u32 *handlep);
308 int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
309 
310 
311 void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
312 int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
313 int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
314 
315 struct page **drm_gem_get_pages(struct drm_gem_object *obj);
316 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
317 		bool dirty, bool accessed);
318 
319 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
320 int drm_gem_dumb_destroy(struct drm_file *file,
321 			 struct drm_device *dev,
322 			 uint32_t handle);
323 
324 #endif /* __DRM_GEM_H__ */
325