xref: /openbmc/linux/include/drm/drm_gem.h (revision d0e22329)
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 struct drm_gem_object;
42 
43 /**
44  * struct drm_gem_object_funcs - GEM object functions
45  */
46 struct drm_gem_object_funcs {
47 	/**
48 	 * @free:
49 	 *
50 	 * Deconstructor for drm_gem_objects.
51 	 *
52 	 * This callback is mandatory.
53 	 */
54 	void (*free)(struct drm_gem_object *obj);
55 
56 	/**
57 	 * @open:
58 	 *
59 	 * Called upon GEM handle creation.
60 	 *
61 	 * This callback is optional.
62 	 */
63 	int (*open)(struct drm_gem_object *obj, struct drm_file *file);
64 
65 	/**
66 	 * @close:
67 	 *
68 	 * Called upon GEM handle release.
69 	 *
70 	 * This callback is optional.
71 	 */
72 	void (*close)(struct drm_gem_object *obj, struct drm_file *file);
73 
74 	/**
75 	 * @print_info:
76 	 *
77 	 * If driver subclasses struct &drm_gem_object, it can implement this
78 	 * optional hook for printing additional driver specific info.
79 	 *
80 	 * drm_printf_indent() should be used in the callback passing it the
81 	 * indent argument.
82 	 *
83 	 * This callback is called from drm_gem_print_info().
84 	 *
85 	 * This callback is optional.
86 	 */
87 	void (*print_info)(struct drm_printer *p, unsigned int indent,
88 			   const struct drm_gem_object *obj);
89 
90 	/**
91 	 * @export:
92 	 *
93 	 * Export backing buffer as a &dma_buf.
94 	 * If this is not set drm_gem_prime_export() is used.
95 	 *
96 	 * This callback is optional.
97 	 */
98 	struct dma_buf *(*export)(struct drm_gem_object *obj, int flags);
99 
100 	/**
101 	 * @pin:
102 	 *
103 	 * Pin backing buffer in memory.
104 	 *
105 	 * This callback is optional.
106 	 */
107 	int (*pin)(struct drm_gem_object *obj);
108 
109 	/**
110 	 * @unpin:
111 	 *
112 	 * Unpin backing buffer.
113 	 *
114 	 * This callback is optional.
115 	 */
116 	void (*unpin)(struct drm_gem_object *obj);
117 
118 	/**
119 	 * @get_sg_table:
120 	 *
121 	 * Returns a Scatter-Gather table representation of the buffer.
122 	 * Used when exporting a buffer.
123 	 *
124 	 * This callback is mandatory if buffer export is supported.
125 	 */
126 	struct sg_table *(*get_sg_table)(struct drm_gem_object *obj);
127 
128 	/**
129 	 * @vmap:
130 	 *
131 	 * Returns a virtual address for the buffer.
132 	 *
133 	 * This callback is optional.
134 	 */
135 	void *(*vmap)(struct drm_gem_object *obj);
136 
137 	/**
138 	 * @vunmap:
139 	 *
140 	 * Releases the the address previously returned by @vmap.
141 	 *
142 	 * This callback is optional.
143 	 */
144 	void (*vunmap)(struct drm_gem_object *obj, void *vaddr);
145 
146 	/**
147 	 * @vm_ops:
148 	 *
149 	 * Virtual memory operations used with mmap.
150 	 *
151 	 * This is optional but necessary for mmap support.
152 	 */
153 	const struct vm_operations_struct *vm_ops;
154 };
155 
156 /**
157  * struct drm_gem_object - GEM buffer object
158  *
159  * This structure defines the generic parts for GEM buffer objects, which are
160  * mostly around handling mmap and userspace handles.
161  *
162  * Buffer objects are often abbreviated to BO.
163  */
164 struct drm_gem_object {
165 	/**
166 	 * @refcount:
167 	 *
168 	 * Reference count of this object
169 	 *
170 	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put()
171 	 * or drm_gem_object_put_unlocked() to release a reference to a GEM
172 	 * buffer object.
173 	 */
174 	struct kref refcount;
175 
176 	/**
177 	 * @handle_count:
178 	 *
179 	 * This is the GEM file_priv handle count of this object.
180 	 *
181 	 * Each handle also holds a reference. Note that when the handle_count
182 	 * drops to 0 any global names (e.g. the id in the flink namespace) will
183 	 * be cleared.
184 	 *
185 	 * Protected by &drm_device.object_name_lock.
186 	 */
187 	unsigned handle_count;
188 
189 	/**
190 	 * @dev: DRM dev this object belongs to.
191 	 */
192 	struct drm_device *dev;
193 
194 	/**
195 	 * @filp:
196 	 *
197 	 * SHMEM file node used as backing storage for swappable buffer objects.
198 	 * GEM also supports driver private objects with driver-specific backing
199 	 * storage (contiguous CMA memory, special reserved blocks). In this
200 	 * case @filp is NULL.
201 	 */
202 	struct file *filp;
203 
204 	/**
205 	 * @vma_node:
206 	 *
207 	 * Mapping info for this object to support mmap. Drivers are supposed to
208 	 * allocate the mmap offset using drm_gem_create_mmap_offset(). The
209 	 * offset itself can be retrieved using drm_vma_node_offset_addr().
210 	 *
211 	 * Memory mapping itself is handled by drm_gem_mmap(), which also checks
212 	 * that userspace is allowed to access the object.
213 	 */
214 	struct drm_vma_offset_node vma_node;
215 
216 	/**
217 	 * @size:
218 	 *
219 	 * Size of the object, in bytes.  Immutable over the object's
220 	 * lifetime.
221 	 */
222 	size_t size;
223 
224 	/**
225 	 * @name:
226 	 *
227 	 * Global name for this object, starts at 1. 0 means unnamed.
228 	 * Access is covered by &drm_device.object_name_lock. This is used by
229 	 * the GEM_FLINK and GEM_OPEN ioctls.
230 	 */
231 	int name;
232 
233 	/**
234 	 * @dma_buf:
235 	 *
236 	 * dma-buf associated with this GEM object.
237 	 *
238 	 * Pointer to the dma-buf associated with this gem object (either
239 	 * through importing or exporting). We break the resulting reference
240 	 * loop when the last gem handle for this object is released.
241 	 *
242 	 * Protected by &drm_device.object_name_lock.
243 	 */
244 	struct dma_buf *dma_buf;
245 
246 	/**
247 	 * @import_attach:
248 	 *
249 	 * dma-buf attachment backing this object.
250 	 *
251 	 * Any foreign dma_buf imported as a gem object has this set to the
252 	 * attachment point for the device. This is invariant over the lifetime
253 	 * of a gem object.
254 	 *
255 	 * The &drm_driver.gem_free_object callback is responsible for cleaning
256 	 * up the dma_buf attachment and references acquired at import time.
257 	 *
258 	 * Note that the drm gem/prime core does not depend upon drivers setting
259 	 * this field any more. So for drivers where this doesn't make sense
260 	 * (e.g. virtual devices or a displaylink behind an usb bus) they can
261 	 * simply leave it as NULL.
262 	 */
263 	struct dma_buf_attachment *import_attach;
264 
265 	/**
266 	 * @funcs:
267 	 *
268 	 * Optional GEM object functions. If this is set, it will be used instead of the
269 	 * corresponding &drm_driver GEM callbacks.
270 	 *
271 	 * New drivers should use this.
272 	 *
273 	 */
274 	const struct drm_gem_object_funcs *funcs;
275 };
276 
277 /**
278  * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
279  * @name: name for the generated structure
280  *
281  * This macro autogenerates a suitable &struct file_operations for GEM based
282  * drivers, which can be assigned to &drm_driver.fops. Note that this structure
283  * cannot be shared between drivers, because it contains a reference to the
284  * current module using THIS_MODULE.
285  *
286  * Note that the declaration is already marked as static - if you need a
287  * non-static version of this you're probably doing it wrong and will break the
288  * THIS_MODULE reference by accident.
289  */
290 #define DEFINE_DRM_GEM_FOPS(name) \
291 	static const struct file_operations name = {\
292 		.owner		= THIS_MODULE,\
293 		.open		= drm_open,\
294 		.release	= drm_release,\
295 		.unlocked_ioctl	= drm_ioctl,\
296 		.compat_ioctl	= drm_compat_ioctl,\
297 		.poll		= drm_poll,\
298 		.read		= drm_read,\
299 		.llseek		= noop_llseek,\
300 		.mmap		= drm_gem_mmap,\
301 	}
302 
303 void drm_gem_object_release(struct drm_gem_object *obj);
304 void drm_gem_object_free(struct kref *kref);
305 int drm_gem_object_init(struct drm_device *dev,
306 			struct drm_gem_object *obj, size_t size);
307 void drm_gem_private_object_init(struct drm_device *dev,
308 				 struct drm_gem_object *obj, size_t size);
309 void drm_gem_vm_open(struct vm_area_struct *vma);
310 void drm_gem_vm_close(struct vm_area_struct *vma);
311 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
312 		     struct vm_area_struct *vma);
313 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
314 
315 /**
316  * drm_gem_object_get - acquire a GEM buffer object reference
317  * @obj: GEM buffer object
318  *
319  * This function acquires an additional reference to @obj. It is illegal to
320  * call this without already holding a reference. No locks required.
321  */
322 static inline void drm_gem_object_get(struct drm_gem_object *obj)
323 {
324 	kref_get(&obj->refcount);
325 }
326 
327 /**
328  * __drm_gem_object_put - raw function to release a GEM buffer object reference
329  * @obj: GEM buffer object
330  *
331  * This function is meant to be used by drivers which are not encumbered with
332  * &drm_device.struct_mutex legacy locking and which are using the
333  * gem_free_object_unlocked callback. It avoids all the locking checks and
334  * locking overhead of drm_gem_object_put() and drm_gem_object_put_unlocked().
335  *
336  * Drivers should never call this directly in their code. Instead they should
337  * wrap it up into a ``driver_gem_object_put(struct driver_gem_object *obj)``
338  * wrapper function, and use that. Shared code should never call this, to
339  * avoid breaking drivers by accident which still depend upon
340  * &drm_device.struct_mutex locking.
341  */
342 static inline void
343 __drm_gem_object_put(struct drm_gem_object *obj)
344 {
345 	kref_put(&obj->refcount, drm_gem_object_free);
346 }
347 
348 void drm_gem_object_put_unlocked(struct drm_gem_object *obj);
349 void drm_gem_object_put(struct drm_gem_object *obj);
350 
351 int drm_gem_handle_create(struct drm_file *file_priv,
352 			  struct drm_gem_object *obj,
353 			  u32 *handlep);
354 int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
355 
356 
357 void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
358 int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
359 int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
360 
361 struct page **drm_gem_get_pages(struct drm_gem_object *obj);
362 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
363 		bool dirty, bool accessed);
364 
365 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
366 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
367 			    u32 handle, u64 *offset);
368 int drm_gem_dumb_destroy(struct drm_file *file,
369 			 struct drm_device *dev,
370 			 uint32_t handle);
371 
372 int drm_gem_pin(struct drm_gem_object *obj);
373 void drm_gem_unpin(struct drm_gem_object *obj);
374 void *drm_gem_vmap(struct drm_gem_object *obj);
375 void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr);
376 
377 #endif /* __DRM_GEM_H__ */
378