drm_framebuffer.h

  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/bits.h>
 27#include <linux/ctype.h>
 28#include <linux/list.h>
 29#include <linux/sched.h>
 30
 31#include <drm/drm_fourcc.h>
 32#include <drm/drm_mode_object.h>
 33
 34struct drm_clip_rect;
 35struct drm_device;
 36struct drm_file;
 37struct drm_framebuffer;
 38struct drm_gem_object;
 39
 40/**
 41 * struct drm_framebuffer_funcs - framebuffer hooks
 42 */
 43struct drm_framebuffer_funcs {
 44	/**
 45	 * @destroy:
 46	 *
 47	 * Clean up framebuffer resources, specifically also unreference the
 48	 * backing storage. The core guarantees to call this function for every
 49	 * framebuffer successfully created by calling
 50	 * &drm_mode_config_funcs.fb_create. Drivers must also call
 51	 * drm_framebuffer_cleanup() to release DRM core resources for this
 52	 * framebuffer.
 53	 */
 54	void (*destroy)(struct drm_framebuffer *framebuffer);
 55
 56	/**
 57	 * @create_handle:
 58	 *
 59	 * Create a buffer handle in the driver-specific buffer manager (either
 60	 * GEM or TTM) valid for the passed-in &struct drm_file. This is used by
 61	 * the core to implement the GETFB IOCTL, which returns (for
 62	 * sufficiently priviledged user) also a native buffer handle. This can
 63	 * be used for seamless transitions between modesetting clients by
 64	 * copying the current screen contents to a private buffer and blending
 65	 * between that and the new contents.
 66	 *
 67	 * GEM based drivers should call drm_gem_handle_create() to create the
 68	 * handle.
 69	 *
 70	 * RETURNS:
 71	 *
 72	 * 0 on success or a negative error code on failure.
 73	 */
 74	int (*create_handle)(struct drm_framebuffer *fb,
 75			     struct drm_file *file_priv,
 76			     unsigned int *handle);
 77	/**
 78	 * @dirty:
 79	 *
 80	 * Optional callback for the dirty fb IOCTL.
 81	 *
 82	 * Userspace can notify the driver via this callback that an area of the
 83	 * framebuffer has changed and should be flushed to the display
 84	 * hardware. This can also be used internally, e.g. by the fbdev
 85	 * emulation, though that's not the case currently.
 86	 *
 87	 * See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd
 88	 * for more information as all the semantics and arguments have a one to
 89	 * one mapping on this function.
 90	 *
 91	 * Atomic drivers should use drm_atomic_helper_dirtyfb() to implement
 92	 * this hook.
 93	 *
 94	 * RETURNS:
 95	 *
 96	 * 0 on success or a negative error code on failure.
 97	 */
 98	int (*dirty)(struct drm_framebuffer *framebuffer,
 99		     struct drm_file *file_priv, unsigned flags,
100		     unsigned color, struct drm_clip_rect *clips,
101		     unsigned num_clips);
102};
103
104#define DRM_FRAMEBUFFER_HAS_HANDLE_REF(_i)	BIT(0u + (_i))
105
106/**
107 * struct drm_framebuffer - frame buffer object
108 *
109 * Note that the fb is refcounted for the benefit of driver internals,
110 * for example some hw, disabling a CRTC/plane is asynchronous, and
111 * scanout does not actually complete until the next vblank.  So some
112 * cleanup (like releasing the reference(s) on the backing GEM bo(s))
113 * should be deferred.  In cases like this, the driver would like to
114 * hold a ref to the fb even though it has already been removed from
115 * userspace perspective. See drm_framebuffer_get() and
116 * drm_framebuffer_put().
117 *
118 * The refcount is stored inside the mode object @base.
119 */
120struct drm_framebuffer {
121	/**
122	 * @dev: DRM device this framebuffer belongs to
123	 */
124	struct drm_device *dev;
125	/**
126	 * @head: Place on the &drm_mode_config.fb_list, access protected by
127	 * &drm_mode_config.fb_lock.
128	 */
129	struct list_head head;
130
131	/**
132	 * @base: base modeset object structure, contains the reference count.
133	 */
134	struct drm_mode_object base;
135
136	/**
137	 * @comm: Name of the process allocating the fb, used for fb dumping.
138	 */
139	char comm[TASK_COMM_LEN];
140
141	/**
142	 * @format: framebuffer format information
143	 */
144	const struct drm_format_info *format;
145	/**
146	 * @funcs: framebuffer vfunc table
147	 */
148	const struct drm_framebuffer_funcs *funcs;
149	/**
150	 * @pitches: Line stride per buffer. For userspace created object this
151	 * is copied from drm_mode_fb_cmd2.
152	 */
153	unsigned int pitches[DRM_FORMAT_MAX_PLANES];
154	/**
155	 * @offsets: Offset from buffer start to the actual pixel data in bytes,
156	 * per buffer. For userspace created object this is copied from
157	 * drm_mode_fb_cmd2.
158	 *
159	 * Note that this is a linear offset and does not take into account
160	 * tiling or buffer layout per @modifier. It is meant to be used when
161	 * the actual pixel data for this framebuffer plane starts at an offset,
162	 * e.g. when multiple planes are allocated within the same backing
163	 * storage buffer object. For tiled layouts this generally means its
164	 * @offsets must at least be tile-size aligned, but hardware often has
165	 * stricter requirements.
166	 *
167	 * This should not be used to specifiy x/y pixel offsets into the buffer
168	 * data (even for linear buffers). Specifying an x/y pixel offset is
169	 * instead done through the source rectangle in &struct drm_plane_state.
170	 */
171	unsigned int offsets[DRM_FORMAT_MAX_PLANES];
172	/**
173	 * @modifier: Data layout modifier. This is used to describe
174	 * tiling, or also special layouts (like compression) of auxiliary
175	 * buffers. For userspace created object this is copied from
176	 * drm_mode_fb_cmd2.
177	 */
178	uint64_t modifier;
179	/**
180	 * @width: Logical width of the visible area of the framebuffer, in
181	 * pixels.
182	 */
183	unsigned int width;
184	/**
185	 * @height: Logical height of the visible area of the framebuffer, in
186	 * pixels.
187	 */
188	unsigned int height;
189	/**
190	 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
191	 * DRM_MODE_FB_MODIFIERS.
192	 */
193	int flags;
194	/**
195	 * @internal_flags: Framebuffer flags like DRM_FRAMEBUFFER_HAS_HANDLE_REF.
196	 */
197	unsigned int internal_flags;
198	/**
199	 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.
200	 */
201	struct list_head filp_head;
202	/**
203	 * @obj: GEM objects backing the framebuffer, one per plane (optional).
204	 *
205	 * This is used by the GEM framebuffer helpers, see e.g.
206	 * drm_gem_fb_create().
207	 */
208	struct drm_gem_object *obj[DRM_FORMAT_MAX_PLANES];
209};
210
211#define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
212
213int drm_framebuffer_init(struct drm_device *dev,
214			 struct drm_framebuffer *fb,
215			 const struct drm_framebuffer_funcs *funcs);
216struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
217					       struct drm_file *file_priv,
218					       uint32_t id);
219void drm_framebuffer_remove(struct drm_framebuffer *fb);
220void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
221void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
222
223/**
224 * drm_framebuffer_get - acquire a framebuffer reference
225 * @fb: DRM framebuffer
226 *
227 * This function increments the framebuffer's reference count.
228 */
229static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
230{
231	drm_mode_object_get(&fb->base);
232}
233
234/**
235 * drm_framebuffer_put - release a framebuffer reference
236 * @fb: DRM framebuffer
237 *
238 * This function decrements the framebuffer's reference count and frees the
239 * framebuffer if the reference count drops to zero.
240 */
241static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
242{
243	drm_mode_object_put(&fb->base);
244}
245
246/**
247 * drm_framebuffer_read_refcount - read the framebuffer reference count.
248 * @fb: framebuffer
249 *
250 * This functions returns the framebuffer's reference count.
251 */
252static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb)
253{
254	return kref_read(&fb->base.refcount);
255}
256
257/**
258 * drm_framebuffer_assign - store a reference to the fb
259 * @p: location to store framebuffer
260 * @fb: new framebuffer (maybe NULL)
261 *
262 * This functions sets the location to store a reference to the framebuffer,
263 * unreferencing the framebuffer that was previously stored in that location.
264 */
265static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
266					  struct drm_framebuffer *fb)
267{
268	if (fb)
269		drm_framebuffer_get(fb);
270	if (*p)
271		drm_framebuffer_put(*p);
272	*p = fb;
273}
274
275/*
276 * drm_for_each_fb - iterate over all framebuffers
277 * @fb: the loop cursor
278 * @dev: the DRM device
279 *
280 * Iterate over all framebuffers of @dev. User must hold
281 * &drm_mode_config.fb_lock.
282 */
283#define drm_for_each_fb(fb, dev) \
284	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),		\
285	     fb = list_first_entry(&(dev)->mode_config.fb_list,	\
286					  struct drm_framebuffer, head);	\
287	     &fb->head != (&(dev)->mode_config.fb_list);			\
288	     fb = list_next_entry(fb, head))
289
290/**
291 * struct drm_afbc_framebuffer - a special afbc frame buffer object
292 *
293 * A derived class of struct drm_framebuffer, dedicated for afbc use cases.
294 */
295struct drm_afbc_framebuffer {
296	/**
297	 * @base: base framebuffer structure.
298	 */
299	struct drm_framebuffer base;
300	/**
301	 * @block_width: width of a single afbc block
302	 */
303	u32 block_width;
304	/**
305	 * @block_height: height of a single afbc block
306	 */
307	u32 block_height;
308	/**
309	 * @aligned_width: aligned frame buffer width
310	 */
311	u32 aligned_width;
312	/**
313	 * @aligned_height: aligned frame buffer height
314	 */
315	u32 aligned_height;
316	/**
317	 * @offset: offset of the first afbc header
318	 */
319	u32 offset;
320	/**
321	 * @afbc_size: minimum size of afbc buffer
322	 */
323	u32 afbc_size;
324};
325
326#define fb_to_afbc_fb(x) container_of(x, struct drm_afbc_framebuffer, base)
327
328#endif