include/drm/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/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