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_mode_object.h>
31
32 struct drm_clip_rect;
33 struct drm_device;
34 struct drm_file;
35 struct drm_format_info;
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[4];
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 laytou per @modifier. It meant to be used when the
158 * 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 it
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[4];
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 * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor
193 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
194 * universal plane.
195 */
196 int hot_x;
197 /**
198 * @hot_y: Y coordinate of the cursor hotspot. Used by the legacy cursor
199 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
200 * universal plane.
201 */
202 int hot_y;
203 /**
204 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.
205 */
206 struct list_head filp_head;
207 /**
208 * @obj: GEM objects backing the framebuffer, one per plane (optional).
209 *
210 * This is used by the GEM framebuffer helpers, see e.g.
211 * drm_gem_fb_create().
212 */
213 struct drm_gem_object *obj[4];
214 };
215
216 #define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
217
218 int drm_framebuffer_init(struct drm_device *dev,
219 struct drm_framebuffer *fb,
220 const struct drm_framebuffer_funcs *funcs);
221 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
222 struct drm_file *file_priv,
223 uint32_t id);
224 void drm_framebuffer_remove(struct drm_framebuffer *fb);
225 void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
226 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
227
228 /**
229 * drm_framebuffer_get - acquire a framebuffer reference
230 * @fb: DRM framebuffer
231 *
232 * This function increments the framebuffer's reference count.
233 */
234 static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
235 {
236 drm_mode_object_get(&fb->base);
237 }
238
239 /**
240 * drm_framebuffer_put - release a framebuffer reference
241 * @fb: DRM framebuffer
242 *
243 * This function decrements the framebuffer's reference count and frees the
244 * framebuffer if the reference count drops to zero.
245 */
246 static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
247 {
248 drm_mode_object_put(&fb->base);
249 }
250
251 /**
252 * drm_framebuffer_read_refcount - read the framebuffer reference count.
253 * @fb: framebuffer
254 *
255 * This functions returns the framebuffer's reference count.
256 */
257 static inline uint32_t drm_framebuffer_read_refcount(const struct drm_framebuffer *fb)
258 {
259 return kref_read(&fb->base.refcount);
260 }
261
262 /**
263 * drm_framebuffer_assign - store a reference to the fb
264 * @p: location to store framebuffer
265 * @fb: new framebuffer (maybe NULL)
266 *
267 * This functions sets the location to store a reference to the framebuffer,
268 * unreferencing the framebuffer that was previously stored in that location.
269 */
270 static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
271 struct drm_framebuffer *fb)
272 {
273 if (fb)
274 drm_framebuffer_get(fb);
275 if (*p)
276 drm_framebuffer_put(*p);
277 *p = fb;
278 }
279
280 /*
281 * drm_for_each_fb - iterate over all framebuffers
282 * @fb: the loop cursor
283 * @dev: the DRM device
284 *
285 * Iterate over all framebuffers of @dev. User must hold
286 * &drm_mode_config.fb_lock.
287 */
288 #define drm_for_each_fb(fb, dev) \
289 for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)), \
290 fb = list_first_entry(&(dev)->mode_config.fb_list, \
291 struct drm_framebuffer, head); \
292 &fb->head != (&(dev)->mode_config.fb_list); \
293 fb = list_next_entry(fb, head))
294
295 int drm_framebuffer_plane_width(int width,
296 const struct drm_framebuffer *fb, int plane);
297 int drm_framebuffer_plane_height(int height,
298 const struct drm_framebuffer *fb, int plane);
299
300 #endif