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 ->fb_create() in
 44	 * &drm_mode_config_funcs. 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_reference() and
105 * drm_framebuffer_unreference().
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 dev->mode_config.fb_list, access protected by
116	 * dev->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	 * @funcs: framebuffer vfunc table
126	 */
127	const struct drm_framebuffer_funcs *funcs;
128	/**
129	 * @pitches: Line stride per buffer. For userspace created object this
130	 * is copied from drm_mode_fb_cmd2.
131	 */
132	unsigned int pitches[4];
133	/**
134	 * @offsets: Offset from buffer start to the actual pixel data in bytes,
135	 * per buffer. For userspace created object this is copied from
136	 * drm_mode_fb_cmd2.
137	 *
138	 * Note that this is a linear offset and does not take into account
139	 * tiling or buffer laytou per @modifier. It meant to be used when the
140	 * actual pixel data for this framebuffer plane starts at an offset,
141	 * e.g.  when multiple planes are allocated within the same backing
142	 * storage buffer object. For tiled layouts this generally means it
143	 * @offsets must at least be tile-size aligned, but hardware often has
144	 * stricter requirements.
145	 *
146	 * This should not be used to specifiy x/y pixel offsets into the buffer
147	 * data (even for linear buffers). Specifying an x/y pixel offset is
148	 * instead done through the source rectangle in struct &drm_plane_state.
149	 */
150	unsigned int offsets[4];
151	/**
152	 * @modifier: Data layout modifier. This is used to describe
153	 * tiling, or also special layouts (like compression) of auxiliary
154	 * buffers. For userspace created object this is copied from
155	 * drm_mode_fb_cmd2.
156	 */
157	uint64_t modifier;
158	/**
159	 * @width: Logical width of the visible area of the framebuffer, in
160	 * pixels.
161	 */
162	unsigned int width;
163	/**
164	 * @height: Logical height of the visible area of the framebuffer, in
165	 * pixels.
166	 */
167	unsigned int height;
168	/**
169	 * @depth: Depth in bits per pixel for RGB formats. 0 for everything
170	 * else. Legacy information derived from @pixel_format, it's suggested to use
171	 * the DRM FOURCC codes and helper functions directly instead.
172	 */
173	unsigned int depth;
174	/**
175	 * @bits_per_pixel: Storage used bits per pixel for RGB formats. 0 for
176	 * everything else. Legacy information derived from @pixel_format, it's
177	 * suggested to use the DRM FOURCC codes and helper functions directly
178	 * instead.
179	 */
180	int bits_per_pixel;
181	/**
182	 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
183	 * DRM_MODE_FB_MODIFIERS.
184	 */
185	int flags;
186	/**
187	 * @pixel_format: DRM FOURCC code describing the pixel format.
188	 */
189	uint32_t pixel_format; /* fourcc format */
190	/**
191	 * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor
192	 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
193	 * universal plane.
194	 */
195	int hot_x;
196	/**
197	 * @hot_y: Y coordinate of the cursor hotspot. Used by the legacy cursor
198	 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
199	 * universal plane.
200	 */
201	int hot_y;
202	/**
203	 * @filp_head: Placed on struct &drm_file fbs list_head, protected by
204	 * fbs_lock in the same structure.
205	 */
206	struct list_head filp_head;
207};
208
209#define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
210
211int drm_framebuffer_init(struct drm_device *dev,
212			 struct drm_framebuffer *fb,
213			 const struct drm_framebuffer_funcs *funcs);
214struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
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_reference - incr the fb refcnt
222 * @fb: framebuffer
223 *
224 * This functions increments the fb's refcount.
225 */
226static inline void drm_framebuffer_reference(struct drm_framebuffer *fb)
227{
228	drm_mode_object_reference(&fb->base);
229}
230
231/**
232 * drm_framebuffer_unreference - unref a framebuffer
233 * @fb: framebuffer to unref
234 *
235 * This functions decrements the fb's refcount and frees it if it drops to zero.
236 */
237static inline void drm_framebuffer_unreference(struct drm_framebuffer *fb)
238{
239	drm_mode_object_unreference(&fb->base);
240}
241
242/**
243 * drm_framebuffer_read_refcount - read the framebuffer reference count.
244 * @fb: framebuffer
245 *
246 * This functions returns the framebuffer's reference count.
247 */
248static inline uint32_t drm_framebuffer_read_refcount(struct drm_framebuffer *fb)
249{
250	return atomic_read(&fb->base.refcount.refcount);
251}
252
253/**
254 * drm_framebuffer_assign - store a reference to the fb
255 * @p: location to store framebuffer
256 * @fb: new framebuffer (maybe NULL)
257 *
258 * This functions sets the location to store a reference to the framebuffer,
259 * unreferencing the framebuffer that was previously stored in that location.
260 */
261static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
262					  struct drm_framebuffer *fb)
263{
264	if (fb)
265		drm_framebuffer_reference(fb);
266	if (*p)
267		drm_framebuffer_unreference(*p);
268	*p = fb;
269}
270
271/*
272 * drm_for_each_fb - iterate over all framebuffers
273 * @fb: the loop cursor
274 * @dev: the DRM device
275 *
276 * Iterate over all framebuffers of @dev. User must hold the fb_lock from
277 * &drm_mode_config.
278 */
279#define drm_for_each_fb(fb, dev) \
280	for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),		\
281	     fb = list_first_entry(&(dev)->mode_config.fb_list,	\
282					  struct drm_framebuffer, head);	\
283	     &fb->head != (&(dev)->mode_config.fb_list);			\
284	     fb = list_next_entry(fb, head))
285#endif