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
30 struct drm_framebuffer;
31 struct drm_file;
32 struct drm_device;
33
34 /**
35 * struct drm_framebuffer_funcs - framebuffer hooks
36 */
37 struct 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 */
109 struct 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 * @format: framebuffer format information
126 */
127 const struct drm_format_info *format;
128 /**
129 * @funcs: framebuffer vfunc table
130 */
131 const struct drm_framebuffer_funcs *funcs;
132 /**
133 * @pitches: Line stride per buffer. For userspace created object this
134 * is copied from drm_mode_fb_cmd2.
135 */
136 unsigned int pitches[4];
137 /**
138 * @offsets: Offset from buffer start to the actual pixel data in bytes,
139 * per buffer. For userspace created object this is copied from
140 * drm_mode_fb_cmd2.
141 *
142 * Note that this is a linear offset and does not take into account
143 * tiling or buffer laytou per @modifier. It meant to be used when the
144 * actual pixel data for this framebuffer plane starts at an offset,
145 * e.g. when multiple planes are allocated within the same backing
146 * storage buffer object. For tiled layouts this generally means it
147 * @offsets must at least be tile-size aligned, but hardware often has
148 * stricter requirements.
149 *
150 * This should not be used to specifiy x/y pixel offsets into the buffer
151 * data (even for linear buffers). Specifying an x/y pixel offset is
152 * instead done through the source rectangle in &struct drm_plane_state.
153 */
154 unsigned int offsets[4];
155 /**
156 * @modifier: Data layout modifier. This is used to describe
157 * tiling, or also special layouts (like compression) of auxiliary
158 * buffers. For userspace created object this is copied from
159 * drm_mode_fb_cmd2.
160 */
161 uint64_t modifier;
162 /**
163 * @width: Logical width of the visible area of the framebuffer, in
164 * pixels.
165 */
166 unsigned int width;
167 /**
168 * @height: Logical height of the visible area of the framebuffer, in
169 * pixels.
170 */
171 unsigned int height;
172 /**
173 * @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
174 * DRM_MODE_FB_MODIFIERS.
175 */
176 int flags;
177 /**
178 * @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor
179 * IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
180 * universal plane.
181 */
182 int hot_x;
183 /**
184 * @hot_y: Y 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_y;
189 /**
190 * @filp_head: Placed on &drm_file.fbs, protected by &drm_file.fbs_lock.
191 */
192 struct list_head filp_head;
193 /**
194 * @obj: GEM objects backing the framebuffer, one per plane (optional).
195 *
196 * This is used by the GEM framebuffer helpers, see e.g.
197 * drm_gem_fb_create().
198 */
199 struct drm_gem_object *obj[4];
200 };
201
202 #define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
203
204 int drm_framebuffer_init(struct drm_device *dev,
205 struct drm_framebuffer *fb,
206 const struct drm_framebuffer_funcs *funcs);
207 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
208 struct drm_file *file_priv,
209 uint32_t id);
210 void drm_framebuffer_remove(struct drm_framebuffer *fb);
211 void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
212 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
213
214 /**
215 * drm_framebuffer_get - acquire a framebuffer reference
216 * @fb: DRM framebuffer
217 *
218 * This function increments the framebuffer's reference count.
219 */
drm_framebuffer_get(struct drm_framebuffer * fb)220 static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
221 {
222 drm_mode_object_get(&fb->base);
223 }
224
225 /**
226 * drm_framebuffer_put - release a framebuffer reference
227 * @fb: DRM framebuffer
228 *
229 * This function decrements the framebuffer's reference count and frees the
230 * framebuffer if the reference count drops to zero.
231 */
drm_framebuffer_put(struct drm_framebuffer * fb)232 static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
233 {
234 drm_mode_object_put(&fb->base);
235 }
236
237 /**
238 * drm_framebuffer_reference - acquire a framebuffer reference
239 * @fb: DRM framebuffer
240 *
241 * This is a compatibility alias for drm_framebuffer_get() and should not be
242 * used by new code.
243 */
drm_framebuffer_reference(struct drm_framebuffer * fb)244 static inline void drm_framebuffer_reference(struct drm_framebuffer *fb)
245 {
246 drm_framebuffer_get(fb);
247 }
248
249 /**
250 * drm_framebuffer_unreference - release a framebuffer reference
251 * @fb: DRM framebuffer
252 *
253 * This is a compatibility alias for drm_framebuffer_put() and should not be
254 * used by new code.
255 */
drm_framebuffer_unreference(struct drm_framebuffer * fb)256 static inline void drm_framebuffer_unreference(struct drm_framebuffer *fb)
257 {
258 drm_framebuffer_put(fb);
259 }
260
261 /**
262 * drm_framebuffer_read_refcount - read the framebuffer reference count.
263 * @fb: framebuffer
264 *
265 * This functions returns the framebuffer's reference count.
266 */
drm_framebuffer_read_refcount(struct drm_framebuffer * fb)267 static inline uint32_t drm_framebuffer_read_refcount(struct drm_framebuffer *fb)
268 {
269 return kref_read(&fb->base.refcount);
270 }
271
272 /**
273 * drm_framebuffer_assign - store a reference to the fb
274 * @p: location to store framebuffer
275 * @fb: new framebuffer (maybe NULL)
276 *
277 * This functions sets the location to store a reference to the framebuffer,
278 * unreferencing the framebuffer that was previously stored in that location.
279 */
drm_framebuffer_assign(struct drm_framebuffer ** p,struct drm_framebuffer * fb)280 static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
281 struct drm_framebuffer *fb)
282 {
283 if (fb)
284 drm_framebuffer_get(fb);
285 if (*p)
286 drm_framebuffer_put(*p);
287 *p = fb;
288 }
289
290 /*
291 * drm_for_each_fb - iterate over all framebuffers
292 * @fb: the loop cursor
293 * @dev: the DRM device
294 *
295 * Iterate over all framebuffers of @dev. User must hold
296 * &drm_mode_config.fb_lock.
297 */
298 #define drm_for_each_fb(fb, dev) \
299 for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)), \
300 fb = list_first_entry(&(dev)->mode_config.fb_list, \
301 struct drm_framebuffer, head); \
302 &fb->head != (&(dev)->mode_config.fb_list); \
303 fb = list_next_entry(fb, head))
304
305 int drm_framebuffer_plane_width(int width,
306 const struct drm_framebuffer *fb, int plane);
307 int drm_framebuffer_plane_height(int height,
308 const struct drm_framebuffer *fb, int plane);
309
310 #endif
311