xref: /linux/include/drm/drm_gem.h (revision 8a79db5e83a5d52c74e6f3c40d6f312cf899213e)
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 #include <linux/dma-resv.h>
39 
40 #include <drm/drm_vma_manager.h>
41 
42 struct drm_gem_object;
43 
44 /**
45  * struct drm_gem_object_funcs - GEM object functions
46  */
47 struct drm_gem_object_funcs {
48 	/**
49 	 * @free:
50 	 *
51 	 * Deconstructor for drm_gem_objects.
52 	 *
53 	 * This callback is mandatory.
54 	 */
55 	void (*free)(struct drm_gem_object *obj);
56 
57 	/**
58 	 * @open:
59 	 *
60 	 * Called upon GEM handle creation.
61 	 *
62 	 * This callback is optional.
63 	 */
64 	int (*open)(struct drm_gem_object *obj, struct drm_file *file);
65 
66 	/**
67 	 * @close:
68 	 *
69 	 * Called upon GEM handle release.
70 	 *
71 	 * This callback is optional.
72 	 */
73 	void (*close)(struct drm_gem_object *obj, struct drm_file *file);
74 
75 	/**
76 	 * @print_info:
77 	 *
78 	 * If driver subclasses struct &drm_gem_object, it can implement this
79 	 * optional hook for printing additional driver specific info.
80 	 *
81 	 * drm_printf_indent() should be used in the callback passing it the
82 	 * indent argument.
83 	 *
84 	 * This callback is called from drm_gem_print_info().
85 	 *
86 	 * This callback is optional.
87 	 */
88 	void (*print_info)(struct drm_printer *p, unsigned int indent,
89 			   const struct drm_gem_object *obj);
90 
91 	/**
92 	 * @export:
93 	 *
94 	 * Export backing buffer as a &dma_buf.
95 	 * If this is not set drm_gem_prime_export() is used.
96 	 *
97 	 * This callback is optional.
98 	 */
99 	struct dma_buf *(*export)(struct drm_gem_object *obj, int flags);
100 
101 	/**
102 	 * @pin:
103 	 *
104 	 * Pin backing buffer in memory. Used by the drm_gem_map_attach() helper.
105 	 *
106 	 * This callback is optional.
107 	 */
108 	int (*pin)(struct drm_gem_object *obj);
109 
110 	/**
111 	 * @unpin:
112 	 *
113 	 * Unpin backing buffer. Used by the drm_gem_map_detach() helper.
114 	 *
115 	 * This callback is optional.
116 	 */
117 	void (*unpin)(struct drm_gem_object *obj);
118 
119 	/**
120 	 * @get_sg_table:
121 	 *
122 	 * Returns a Scatter-Gather table representation of the buffer.
123 	 * Used when exporting a buffer by the drm_gem_map_dma_buf() helper.
124 	 * Releasing is done by calling dma_unmap_sg_attrs() and sg_free_table()
125 	 * in drm_gem_unmap_buf(), therefore these helpers and this callback
126 	 * here cannot be used for sg tables pointing at driver private memory
127 	 * ranges.
128 	 *
129 	 * See also drm_prime_pages_to_sg().
130 	 */
131 	struct sg_table *(*get_sg_table)(struct drm_gem_object *obj);
132 
133 	/**
134 	 * @vmap:
135 	 *
136 	 * Returns a virtual address for the buffer. Used by the
137 	 * drm_gem_dmabuf_vmap() helper.
138 	 *
139 	 * This callback is optional.
140 	 */
141 	void *(*vmap)(struct drm_gem_object *obj);
142 
143 	/**
144 	 * @vunmap:
145 	 *
146 	 * Releases the the address previously returned by @vmap. Used by the
147 	 * drm_gem_dmabuf_vunmap() helper.
148 	 *
149 	 * This callback is optional.
150 	 */
151 	void (*vunmap)(struct drm_gem_object *obj, void *vaddr);
152 
153 	/**
154 	 * @mmap:
155 	 *
156 	 * Handle mmap() of the gem object, setup vma accordingly.
157 	 *
158 	 * This callback is optional.
159 	 *
160 	 * The callback is used by by both drm_gem_mmap_obj() and
161 	 * drm_gem_prime_mmap().  When @mmap is present @vm_ops is not
162 	 * used, the @mmap callback must set vma->vm_ops instead. The @mmap
163 	 * callback is always called with a 0 offset. The caller will remove
164 	 * the fake offset as necessary.
165 	 */
166 	int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);
167 
168 	/**
169 	 * @vm_ops:
170 	 *
171 	 * Virtual memory operations used with mmap.
172 	 *
173 	 * This is optional but necessary for mmap support.
174 	 */
175 	const struct vm_operations_struct *vm_ops;
176 };
177 
178 /**
179  * struct drm_gem_object - GEM buffer object
180  *
181  * This structure defines the generic parts for GEM buffer objects, which are
182  * mostly around handling mmap and userspace handles.
183  *
184  * Buffer objects are often abbreviated to BO.
185  */
186 struct drm_gem_object {
187 	/**
188 	 * @refcount:
189 	 *
190 	 * Reference count of this object
191 	 *
192 	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put()
193 	 * or drm_gem_object_put_unlocked() to release a reference to a GEM
194 	 * buffer object.
195 	 */
196 	struct kref refcount;
197 
198 	/**
199 	 * @handle_count:
200 	 *
201 	 * This is the GEM file_priv handle count of this object.
202 	 *
203 	 * Each handle also holds a reference. Note that when the handle_count
204 	 * drops to 0 any global names (e.g. the id in the flink namespace) will
205 	 * be cleared.
206 	 *
207 	 * Protected by &drm_device.object_name_lock.
208 	 */
209 	unsigned handle_count;
210 
211 	/**
212 	 * @dev: DRM dev this object belongs to.
213 	 */
214 	struct drm_device *dev;
215 
216 	/**
217 	 * @filp:
218 	 *
219 	 * SHMEM file node used as backing storage for swappable buffer objects.
220 	 * GEM also supports driver private objects with driver-specific backing
221 	 * storage (contiguous CMA memory, special reserved blocks). In this
222 	 * case @filp is NULL.
223 	 */
224 	struct file *filp;
225 
226 	/**
227 	 * @vma_node:
228 	 *
229 	 * Mapping info for this object to support mmap. Drivers are supposed to
230 	 * allocate the mmap offset using drm_gem_create_mmap_offset(). The
231 	 * offset itself can be retrieved using drm_vma_node_offset_addr().
232 	 *
233 	 * Memory mapping itself is handled by drm_gem_mmap(), which also checks
234 	 * that userspace is allowed to access the object.
235 	 */
236 	struct drm_vma_offset_node vma_node;
237 
238 	/**
239 	 * @size:
240 	 *
241 	 * Size of the object, in bytes.  Immutable over the object's
242 	 * lifetime.
243 	 */
244 	size_t size;
245 
246 	/**
247 	 * @name:
248 	 *
249 	 * Global name for this object, starts at 1. 0 means unnamed.
250 	 * Access is covered by &drm_device.object_name_lock. This is used by
251 	 * the GEM_FLINK and GEM_OPEN ioctls.
252 	 */
253 	int name;
254 
255 	/**
256 	 * @dma_buf:
257 	 *
258 	 * dma-buf associated with this GEM object.
259 	 *
260 	 * Pointer to the dma-buf associated with this gem object (either
261 	 * through importing or exporting). We break the resulting reference
262 	 * loop when the last gem handle for this object is released.
263 	 *
264 	 * Protected by &drm_device.object_name_lock.
265 	 */
266 	struct dma_buf *dma_buf;
267 
268 	/**
269 	 * @import_attach:
270 	 *
271 	 * dma-buf attachment backing this object.
272 	 *
273 	 * Any foreign dma_buf imported as a gem object has this set to the
274 	 * attachment point for the device. This is invariant over the lifetime
275 	 * of a gem object.
276 	 *
277 	 * The &drm_driver.gem_free_object callback is responsible for cleaning
278 	 * up the dma_buf attachment and references acquired at import time.
279 	 *
280 	 * Note that the drm gem/prime core does not depend upon drivers setting
281 	 * this field any more. So for drivers where this doesn't make sense
282 	 * (e.g. virtual devices or a displaylink behind an usb bus) they can
283 	 * simply leave it as NULL.
284 	 */
285 	struct dma_buf_attachment *import_attach;
286 
287 	/**
288 	 * @resv:
289 	 *
290 	 * Pointer to reservation object associated with the this GEM object.
291 	 *
292 	 * Normally (@resv == &@_resv) except for imported GEM objects.
293 	 */
294 	struct dma_resv *resv;
295 
296 	/**
297 	 * @_resv:
298 	 *
299 	 * A reservation object for this GEM object.
300 	 *
301 	 * This is unused for imported GEM objects.
302 	 */
303 	struct dma_resv _resv;
304 
305 	/**
306 	 * @funcs:
307 	 *
308 	 * Optional GEM object functions. If this is set, it will be used instead of the
309 	 * corresponding &drm_driver GEM callbacks.
310 	 *
311 	 * New drivers should use this.
312 	 *
313 	 */
314 	const struct drm_gem_object_funcs *funcs;
315 };
316 
317 /**
318  * DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
319  * @name: name for the generated structure
320  *
321  * This macro autogenerates a suitable &struct file_operations for GEM based
322  * drivers, which can be assigned to &drm_driver.fops. Note that this structure
323  * cannot be shared between drivers, because it contains a reference to the
324  * current module using THIS_MODULE.
325  *
326  * Note that the declaration is already marked as static - if you need a
327  * non-static version of this you're probably doing it wrong and will break the
328  * THIS_MODULE reference by accident.
329  */
330 #define DEFINE_DRM_GEM_FOPS(name) \
331 	static const struct file_operations name = {\
332 		.owner		= THIS_MODULE,\
333 		.open		= drm_open,\
334 		.release	= drm_release,\
335 		.unlocked_ioctl	= drm_ioctl,\
336 		.compat_ioctl	= drm_compat_ioctl,\
337 		.poll		= drm_poll,\
338 		.read		= drm_read,\
339 		.llseek		= noop_llseek,\
340 		.mmap		= drm_gem_mmap,\
341 	}
342 
343 void drm_gem_object_release(struct drm_gem_object *obj);
344 void drm_gem_object_free(struct kref *kref);
345 int drm_gem_object_init(struct drm_device *dev,
346 			struct drm_gem_object *obj, size_t size);
347 void drm_gem_private_object_init(struct drm_device *dev,
348 				 struct drm_gem_object *obj, size_t size);
349 void drm_gem_vm_open(struct vm_area_struct *vma);
350 void drm_gem_vm_close(struct vm_area_struct *vma);
351 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
352 		     struct vm_area_struct *vma);
353 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
354 
355 /**
356  * drm_gem_object_get - acquire a GEM buffer object reference
357  * @obj: GEM buffer object
358  *
359  * This function acquires an additional reference to @obj. It is illegal to
360  * call this without already holding a reference. No locks required.
361  */
362 static inline void drm_gem_object_get(struct drm_gem_object *obj)
363 {
364 	kref_get(&obj->refcount);
365 }
366 
367 /**
368  * __drm_gem_object_put - raw function to release a GEM buffer object reference
369  * @obj: GEM buffer object
370  *
371  * This function is meant to be used by drivers which are not encumbered with
372  * &drm_device.struct_mutex legacy locking and which are using the
373  * gem_free_object_unlocked callback. It avoids all the locking checks and
374  * locking overhead of drm_gem_object_put() and drm_gem_object_put_unlocked().
375  *
376  * Drivers should never call this directly in their code. Instead they should
377  * wrap it up into a ``driver_gem_object_put(struct driver_gem_object *obj)``
378  * wrapper function, and use that. Shared code should never call this, to
379  * avoid breaking drivers by accident which still depend upon
380  * &drm_device.struct_mutex locking.
381  */
382 static inline void
383 __drm_gem_object_put(struct drm_gem_object *obj)
384 {
385 	kref_put(&obj->refcount, drm_gem_object_free);
386 }
387 
388 void drm_gem_object_put_unlocked(struct drm_gem_object *obj);
389 void drm_gem_object_put(struct drm_gem_object *obj);
390 
391 int drm_gem_handle_create(struct drm_file *file_priv,
392 			  struct drm_gem_object *obj,
393 			  u32 *handlep);
394 int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
395 
396 
397 void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
398 int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
399 int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
400 
401 struct page **drm_gem_get_pages(struct drm_gem_object *obj);
402 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
403 		bool dirty, bool accessed);
404 
405 int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
406 			   int count, struct drm_gem_object ***objs_out);
407 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
408 long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
409 				    bool wait_all, unsigned long timeout);
410 int drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
411 			      struct ww_acquire_ctx *acquire_ctx);
412 void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
413 				 struct ww_acquire_ctx *acquire_ctx);
414 int drm_gem_fence_array_add(struct xarray *fence_array,
415 			    struct dma_fence *fence);
416 int drm_gem_fence_array_add_implicit(struct xarray *fence_array,
417 				     struct drm_gem_object *obj,
418 				     bool write);
419 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
420 			    u32 handle, u64 *offset);
421 int drm_gem_dumb_destroy(struct drm_file *file,
422 			 struct drm_device *dev,
423 			 uint32_t handle);
424 
425 #endif /* __DRM_GEM_H__ */
426