1  /*
2   * Copyright (c) 2016 Intel Corporation
3   *
4   * Permission to use, copy, modify, distribute, and sell this software and its
5   * documentation for any purpose is hereby granted without fee, provided that
6   * the above copyright notice appear in all copies and that both that copyright
7   * notice and this permission notice appear in supporting documentation, and
8   * that the name of the copyright holders not be used in advertising or
9   * publicity pertaining to distribution of the software without specific,
10   * written prior permission.  The copyright holders make no representations
11   * about the suitability of this software for any purpose.  It is provided "as
12   * is" without express or implied warranty.
13   *
14   * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15   * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16   * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17   * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18   * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19   * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20   * OF THIS SOFTWARE.
21   */
22  
23  #ifndef __DRM_FRAMEBUFFER_H__
24  #define __DRM_FRAMEBUFFER_H__
25  
26  #include <linux/ctype.h>
27  #include <linux/list.h>
28  #include <linux/sched.h>
29  
30  #include <drm/drm_fourcc.h>
31  #include <drm/drm_mode_object.h>
32  
33  struct drm_clip_rect;
34  struct drm_device;
35  struct drm_file;
36  struct drm_framebuffer;
37  struct drm_gem_object;
38  
39  /**
40   * struct drm_framebuffer_funcs - framebuffer hooks
41   */
42  struct drm_framebuffer_funcs {
43  	/**
44  	 * @destroy:
45  	 *
46  	 * Clean up framebuffer resources, specifically also unreference the
47  	 * backing storage. The core guarantees to call this function for every
48  	 * framebuffer successfully created by calling
49  	 * &drm_mode_config_funcs.fb_create. Drivers must also call
50  	 * drm_framebuffer_cleanup() to release DRM core resources for this
51  	 * framebuffer.
52  	 */
53  	void (*destroy)(struct drm_framebuffer *framebuffer);
54  
55  	/**
56  	 * @create_handle:
57  	 *
58  	 * Create a buffer handle in the driver-specific buffer manager (either
59  	 * GEM or TTM) valid for the passed-in &struct drm_file. This is used by
60  	 * the core to implement the GETFB IOCTL, which returns (for
61  	 * sufficiently priviledged user) also a native buffer handle. This can
62  	 * be used for seamless transitions between modesetting clients by
63  	 * copying the current screen contents to a private buffer and blending
64  	 * between that and the new contents.
65  	 *
66  	 * GEM based drivers should call drm_gem_handle_create() to create the
67  	 * handle.
68  	 *
69  	 * RETURNS:
70  	 *
71  	 * 0 on success or a negative error code on failure.
72  	 */
73  	int (*create_handle)(struct drm_framebuffer *fb,
74  			     struct drm_file *file_priv,
75  			     unsigned int *handle);
76  	/**
77  	 * @dirty:
78  	 *
79  	 * Optional callback for the dirty fb IOCTL.
80  	 *
81  	 * Userspace can notify the driver via this callback that an area of the
82  	 * framebuffer has changed and should be flushed to the display
83  	 * hardware. This can also be used internally, e.g. by the fbdev
84  	 * emulation, though that's not the case currently.
85  	 *
86  	 * See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd
87  	 * for more information as all the semantics and arguments have a one to
88  	 * one mapping on this function.
89  	 *
90  	 * Atomic drivers should use drm_atomic_helper_dirtyfb() to implement
91  	 * this hook.
92  	 *
93  	 * RETURNS:
94  	 *
95  	 * 0 on success or a negative error code on failure.
96  	 */
97  	int (*dirty)(struct drm_framebuffer *framebuffer,
98  		     struct drm_file *file_priv, unsigned flags,
99  		     unsigned color, struct drm_clip_rect *clips,
100  		     unsigned num_clips);
101  };
102  
103  /**
104   * struct drm_framebuffer - frame buffer object
105   *
106   * Note that the fb is refcounted for the benefit of driver internals,
107   * for example some hw, disabling a CRTC/plane is asynchronous, and
108   * scanout does not actually complete until the next vblank.  So some
109   * cleanup (like releasing the reference(s) on the backing GEM bo(s))
110   * should be deferred.  In cases like this, the driver would like to
111   * hold a ref to the fb even though it has already been removed from
112   * userspace perspective. See drm_framebuffer_get() and
113   * drm_framebuffer_put().
114   *
115   * The refcount is stored inside the mode object @base.
116   */
117  struct drm_framebuffer {
118  	/**
119  	 * @dev: DRM device this framebuffer belongs to
120  	 */
121  	struct drm_device *dev;
122  	/**
123  	 * @head: Place on the &drm_mode_config.fb_list, access protected by
124  	 * &drm_mode_config.fb_lock.
125  	 */
126  	struct list_head head;
127  
128  	/**
129  	 * @base: base modeset object structure, contains the reference count.
130  	 */
131  	struct drm_mode_object base;
132  
133  	/**
134  	 * @comm: Name of the process allocating the fb, used for fb dumping.
135  	 */
136  	char comm[TASK_COMM_LEN];
137  
138  	/**
139  	 * @format: framebuffer format information
140  	 */
141  	const struct drm_format_info *format;
142  	/**
143  	 * @funcs: framebuffer vfunc table
144  	 */
145  	const struct drm_framebuffer_funcs *funcs;
146  	/**
147  	 * @pitches: Line stride per buffer. For userspace created object this
148  	 * is copied from drm_mode_fb_cmd2.
149  	 */
150  	unsigned int pitches[DRM_FORMAT_MAX_PLANES];
151  	/**
152  	 * @offsets: Offset from buffer start to the actual pixel data in bytes,
153  	 * per buffer. For userspace created object this is copied from
154  	 * drm_mode_fb_cmd2.
155  	 *
156  	 * Note that this is a linear offset and does not take into account
157  	 * tiling or buffer layout per @modifier. It is meant to be used when
158  	 * the actual pixel data for this framebuffer plane starts at an offset,
159  	 * e.g. when multiple planes are allocated within the same backing
160  	 * storage buffer object. For tiled layouts this generally means its
161  	 * @offsets must at least be tile-size aligned, but hardware often has
162  	 * stricter requirements.
163  	 *
164  	 * This should not be used to specifiy x/y pixel offsets into the buffer
165  	 * data (even for linear buffers). Specifying an x/y pixel offset is
166  	 * instead done through the source rectangle in &struct drm_plane_state.
167  	 */
168  	unsigned int offsets[DRM_FORMAT_MAX_PLANES];
169  	/**
170  	 * @modifier: Data layout modifier. This is used to describe
171  	 * tiling, or also special layouts (like compression) of auxiliary
172  	 * buffers. For userspace created object this is copied from
173  	 * drm_mode_fb_cmd2.
174  	 */
175  	uint64_t modifier;
176  	/**
177  	 * @width: Logical width of the visible area of the framebuffer, in
178  	 * pixels.
179  	 */
180  	unsigned int width;
181  	/**
182  	 * @height: Logical height of the visible area of the framebuffer, in
183  	 * pixels.
184  	 */
185  	unsigned int height;
186  	/**
187  	 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
188  	 * DRM_MODE_FB_MODIFIERS.
189  	 */
190  	int flags;
191  	/**
192  	 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.
193  	 */
194  	struct list_head filp_head;
195  	/**
196  	 * @obj: GEM objects backing the framebuffer, one per plane (optional).
197  	 *
198  	 * This is used by the GEM framebuffer helpers, see e.g.
199  	 * drm_gem_fb_create().
200  	 */
201  	struct drm_gem_object *obj[DRM_FORMAT_MAX_PLANES];
202  };
203  
204  #define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
205  
206  int drm_framebuffer_init(struct drm_device *dev,
207  			 struct drm_framebuffer *fb,
208  			 const struct drm_framebuffer_funcs *funcs);
209  struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
210  					       struct drm_file *file_priv,
211  					       uint32_t id);
212  void drm_framebuffer_remove(struct drm_framebuffer *fb);
213  void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
214  void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
215  
216  /**
217   * drm_framebuffer_get - acquire a framebuffer reference
218   * @fb: DRM framebuffer
219   *
220   * This function increments the framebuffer's reference count.
221   */
drm_framebuffer_get(struct drm_framebuffer * fb)222  static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
223  {
224  	drm_mode_object_get(&fb->base);
225  }
226  
227  /**
228   * drm_framebuffer_put - release a framebuffer reference
229   * @fb: DRM framebuffer
230   *
231   * This function decrements the framebuffer's reference count and frees the
232   * framebuffer if the reference count drops to zero.
233   */
drm_framebuffer_put(struct drm_framebuffer * fb)234  static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
235  {
236  	drm_mode_object_put(&fb->base);
237  }
238  
239  /**
240   * drm_framebuffer_read_refcount - read the framebuffer reference count.
241   * @fb: framebuffer
242   *
243   * This functions returns the framebuffer's reference count.
244   */
drm_framebuffer_read_refcount(const struct drm_framebuffer * fb)245  static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb)
246  {
247  	return kref_read(&fb->base.refcount);
248  }
249  
250  /**
251   * drm_framebuffer_assign - store a reference to the fb
252   * @p: location to store framebuffer
253   * @fb: new framebuffer (maybe NULL)
254   *
255   * This functions sets the location to store a reference to the framebuffer,
256   * unreferencing the framebuffer that was previously stored in that location.
257   */
drm_framebuffer_assign(struct drm_framebuffer ** p,struct drm_framebuffer * fb)258  static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
259  					  struct drm_framebuffer *fb)
260  {
261  	if (fb)
262  		drm_framebuffer_get(fb);
263  	if (*p)
264  		drm_framebuffer_put(*p);
265  	*p = fb;
266  }
267  
268  /*
269   * drm_for_each_fb - iterate over all framebuffers
270   * @fb: the loop cursor
271   * @dev: the DRM device
272   *
273   * Iterate over all framebuffers of @dev. User must hold
274   * &drm_mode_config.fb_lock.
275   */
276  #define drm_for_each_fb(fb, dev) \
277  	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),		\
278  	     fb = list_first_entry(&(dev)->mode_config.fb_list,	\
279  					  struct drm_framebuffer, head);	\
280  	     &fb->head != (&(dev)->mode_config.fb_list);			\
281  	     fb = list_next_entry(fb, head))
282  
283  /**
284   * struct drm_afbc_framebuffer - a special afbc frame buffer object
285   *
286   * A derived class of struct drm_framebuffer, dedicated for afbc use cases.
287   */
288  struct drm_afbc_framebuffer {
289  	/**
290  	 * @base: base framebuffer structure.
291  	 */
292  	struct drm_framebuffer base;
293  	/**
294  	 * @block_width: width of a single afbc block
295  	 */
296  	u32 block_width;
297  	/**
298  	 * @block_height: height of a single afbc block
299  	 */
300  	u32 block_height;
301  	/**
302  	 * @aligned_width: aligned frame buffer width
303  	 */
304  	u32 aligned_width;
305  	/**
306  	 * @aligned_height: aligned frame buffer height
307  	 */
308  	u32 aligned_height;
309  	/**
310  	 * @offset: offset of the first afbc header
311  	 */
312  	u32 offset;
313  	/**
314  	 * @afbc_size: minimum size of afbc buffer
315  	 */
316  	u32 afbc_size;
317  };
318  
319  #define fb_to_afbc_fb(x) container_of(x, struct drm_afbc_framebuffer, base)
320  
321  #endif
322