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/list.h>
 27#include <linux/ctype.h>
 28#include <drm/drm_mode_object.h>
 29
 30struct drm_framebuffer;
 31struct drm_file;
 32struct drm_device;
 33
 34/**
 35 * struct drm_framebuffer_funcs - framebuffer hooks
 36 */
 37struct drm_framebuffer_funcs {
 38	/**
 39	 * @destroy:
 40	 *
 41	 * Clean up framebuffer resources, specifically also unreference the
 42	 * backing storage. The core guarantees to call this function for every
 43	 * framebuffer successfully created by calling
 44	 * &drm_mode_config_funcs.fb_create. Drivers must also call
 45	 * drm_framebuffer_cleanup() to release DRM core resources for this
 46	 * framebuffer.
 47	 */
 48	void (*destroy)(struct drm_framebuffer *framebuffer);
 49
 50	/**
 51	 * @create_handle:
 52	 *
 53	 * Create a buffer handle in the driver-specific buffer manager (either
 54	 * GEM or TTM) valid for the passed-in &struct drm_file. This is used by
 55	 * the core to implement the GETFB IOCTL, which returns (for
 56	 * sufficiently priviledged user) also a native buffer handle. This can
 57	 * be used for seamless transitions between modesetting clients by
 58	 * copying the current screen contents to a private buffer and blending
 59	 * between that and the new contents.
 60	 *
 61	 * GEM based drivers should call drm_gem_handle_create() to create the
 62	 * handle.
 63	 *
 64	 * RETURNS:
 65	 *
 66	 * 0 on success or a negative error code on failure.
 67	 */
 68	int (*create_handle)(struct drm_framebuffer *fb,
 69			     struct drm_file *file_priv,
 70			     unsigned int *handle);
 71	/**
 72	 * @dirty:
 73	 *
 74	 * Optional callback for the dirty fb IOCTL.
 75	 *
 76	 * Userspace can notify the driver via this callback that an area of the
 77	 * framebuffer has changed and should be flushed to the display
 78	 * hardware. This can also be used internally, e.g. by the fbdev
 79	 * emulation, though that's not the case currently.
 80	 *
 81	 * See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd
 82	 * for more information as all the semantics and arguments have a one to
 83	 * one mapping on this function.
 84	 *
 85	 * RETURNS:
 86	 *
 87	 * 0 on success or a negative error code on failure.
 88	 */
 89	int (*dirty)(struct drm_framebuffer *framebuffer,
 90		     struct drm_file *file_priv, unsigned flags,
 91		     unsigned color, struct drm_clip_rect *clips,
 92		     unsigned num_clips);
 93};
 94
 95/**
 96 * struct drm_framebuffer - frame buffer object
 97 *
 98 * Note that the fb is refcounted for the benefit of driver internals,
 99 * for example some hw, disabling a CRTC/plane is asynchronous, and
100 * scanout does not actually complete until the next vblank.  So some
101 * cleanup (like releasing the reference(s) on the backing GEM bo(s))
102 * should be deferred.  In cases like this, the driver would like to
103 * hold a ref to the fb even though it has already been removed from
104 * userspace perspective. See drm_framebuffer_get() and
105 * drm_framebuffer_put().
106 *
107 * The refcount is stored inside the mode object @base.
108 */
109struct drm_framebuffer {
110	/**
111	 * @dev: DRM device this framebuffer belongs to
112	 */
113	struct drm_device *dev;
114	/**
115	 * @head: Place on the &drm_mode_config.fb_list, access protected by
116	 * &drm_mode_config.fb_lock.
117	 */
118	struct list_head head;
119
120	/**
121	 * @base: base modeset object structure, contains the reference count.
122	 */
123	struct drm_mode_object base;
124
125	/**
126	 * @comm: Name of the process allocating the fb, used for fb dumping.
127	 */
128	char comm[TASK_COMM_LEN];
129
130	/**
131	 * @format: framebuffer format information
132	 */
133	const struct drm_format_info *format;
134	/**
135	 * @funcs: framebuffer vfunc table
136	 */
137	const struct drm_framebuffer_funcs *funcs;
138	/**
139	 * @pitches: Line stride per buffer. For userspace created object this
140	 * is copied from drm_mode_fb_cmd2.
141	 */
142	unsigned int pitches[4];
143	/**
144	 * @offsets: Offset from buffer start to the actual pixel data in bytes,
145	 * per buffer. For userspace created object this is copied from
146	 * drm_mode_fb_cmd2.
147	 *
148	 * Note that this is a linear offset and does not take into account
149	 * tiling or buffer laytou per @modifier. It meant to be used when the
150	 * actual pixel data for this framebuffer plane starts at an offset,
151	 * e.g.  when multiple planes are allocated within the same backing
152	 * storage buffer object. For tiled layouts this generally means it
153	 * @offsets must at least be tile-size aligned, but hardware often has
154	 * stricter requirements.
155	 *
156	 * This should not be used to specifiy x/y pixel offsets into the buffer
157	 * data (even for linear buffers). Specifying an x/y pixel offset is
158	 * instead done through the source rectangle in &struct drm_plane_state.
159	 */
160	unsigned int offsets[4];
161	/**
162	 * @modifier: Data layout modifier. This is used to describe
163	 * tiling, or also special layouts (like compression) of auxiliary
164	 * buffers. For userspace created object this is copied from
165	 * drm_mode_fb_cmd2.
166	 */
167	uint64_t modifier;
168	/**
169	 * @width: Logical width of the visible area of the framebuffer, in
170	 * pixels.
171	 */
172	unsigned int width;
173	/**
174	 * @height: Logical height of the visible area of the framebuffer, in
175	 * pixels.
176	 */
177	unsigned int height;
178	/**
179	 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
180	 * DRM_MODE_FB_MODIFIERS.
181	 */
182	int flags;
183	/**
184	 * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor
185	 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
186	 * universal plane.
187	 */
188	int hot_x;
189	/**
190	 * @hot_y: Y coordinate of the cursor hotspot. Used by the legacy cursor
191	 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
192	 * universal plane.
193	 */
194	int hot_y;
195	/**
196	 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.
197	 */
198	struct list_head filp_head;
199	/**
200	 * @obj: GEM objects backing the framebuffer, one per plane (optional).
201	 *
202	 * This is used by the GEM framebuffer helpers, see e.g.
203	 * drm_gem_fb_create().
204	 */
205	struct drm_gem_object *obj[4];
206};
207
208#define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
209
210int drm_framebuffer_init(struct drm_device *dev,
211			 struct drm_framebuffer *fb,
212			 const struct drm_framebuffer_funcs *funcs);
213struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
214					       struct drm_file *file_priv,
215					       uint32_t id);
216void drm_framebuffer_remove(struct drm_framebuffer *fb);
217void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
218void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
219
220/**
221 * drm_framebuffer_get - acquire a framebuffer reference
222 * @fb: DRM framebuffer
223 *
224 * This function increments the framebuffer's reference count.
225 */
226static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
227{
228	drm_mode_object_get(&fb->base);
229}
230
231/**
232 * drm_framebuffer_put - release a framebuffer reference
233 * @fb: DRM framebuffer
234 *
235 * This function decrements the framebuffer's reference count and frees the
236 * framebuffer if the reference count drops to zero.
237 */
238static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
239{
240	drm_mode_object_put(&fb->base);
241}
242
243/**
244 * drm_framebuffer_reference - acquire a framebuffer reference
245 * @fb: DRM framebuffer
246 *
247 * This is a compatibility alias for drm_framebuffer_get() and should not be
248 * used by new code.
249 */
250static inline void drm_framebuffer_reference(struct drm_framebuffer *fb)
251{
252	drm_framebuffer_get(fb);
253}
254
255/**
256 * drm_framebuffer_unreference - release a framebuffer reference
257 * @fb: DRM framebuffer
258 *
259 * This is a compatibility alias for drm_framebuffer_put() and should not be
260 * used by new code.
261 */
262static inline void drm_framebuffer_unreference(struct drm_framebuffer *fb)
263{
264	drm_framebuffer_put(fb);
265}
266
267/**
268 * drm_framebuffer_read_refcount - read the framebuffer reference count.
269 * @fb: framebuffer
270 *
271 * This functions returns the framebuffer's reference count.
272 */
273static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb)
274{
275	return kref_read(&fb->base.refcount);
276}
277
278/**
279 * drm_framebuffer_assign - store a reference to the fb
280 * @p: location to store framebuffer
281 * @fb: new framebuffer (maybe NULL)
282 *
283 * This functions sets the location to store a reference to the framebuffer,
284 * unreferencing the framebuffer that was previously stored in that location.
285 */
286static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
287					  struct drm_framebuffer *fb)
288{
289	if (fb)
290		drm_framebuffer_get(fb);
291	if (*p)
292		drm_framebuffer_put(*p);
293	*p = fb;
294}
295
296/*
297 * drm_for_each_fb - iterate over all framebuffers
298 * @fb: the loop cursor
299 * @dev: the DRM device
300 *
301 * Iterate over all framebuffers of @dev. User must hold
302 * &drm_mode_config.fb_lock.
303 */
304#define drm_for_each_fb(fb, dev) \
305	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),		\
306	     fb = list_first_entry(&(dev)->mode_config.fb_list,	\
307					  struct drm_framebuffer, head);	\
308	     &fb->head != (&(dev)->mode_config.fb_list);			\
309	     fb = list_next_entry(fb, head))
310
311int drm_framebuffer_plane_width(int width,
312				const struct drm_framebuffer *fb, int plane);
313int drm_framebuffer_plane_height(int height,
314				 const struct drm_framebuffer *fb, int plane);
315
316#endif