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/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                                                uint32_t id);
 209 void drm_framebuffer_remove(struct drm_framebuffer *fb);
 210 void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
 211 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
 212
 213 /**
 214  * drm_framebuffer_get - acquire a framebuffer reference
 215  * @fb: DRM framebuffer
 216  *
 217  * This function increments the framebuffer's reference count.
 218  */
 219 static inline void drm_framebuffer_get(struct drm_framebuffer *fb)
 220 {
 221         drm_mode_object_get(&fb->base);
 222 }
 223
 224 /**
 225  * drm_framebuffer_put - release a framebuffer reference
 226  * @fb: DRM framebuffer
 227  *
 228  * This function decrements the framebuffer's reference count and frees the
 229  * framebuffer if the reference count drops to zero.
 230  */
 231 static inline void drm_framebuffer_put(struct drm_framebuffer *fb)
 232 {
 233         drm_mode_object_put(&fb->base);
 234 }
 235
 236 /**
 237  * drm_framebuffer_reference - acquire a framebuffer reference
 238  * @fb: DRM framebuffer
 239  *
 240  * This is a compatibility alias for drm_framebuffer_get() and should not be
 241  * used by new code.
 242  */
 243 static inline void drm_framebuffer_reference(struct drm_framebuffer *fb)
 244 {
 245         drm_framebuffer_get(fb);
 246 }
 247
 248 /**
 249  * drm_framebuffer_unreference - release a framebuffer reference
 250  * @fb: DRM framebuffer
 251  *
 252  * This is a compatibility alias for drm_framebuffer_put() and should not be
 253  * used by new code.
 254  */
 255 static inline void drm_framebuffer_unreference(struct drm_framebuffer *fb)
 256 {
 257         drm_framebuffer_put(fb);
 258 }
 259
 260 /**
 261  * drm_framebuffer_read_refcount - read the framebuffer reference count.
 262  * @fb: framebuffer
 263  *
 264  * This functions returns the framebuffer's reference count.
 265  */
 266 static inline uint32_t drm_framebuffer_read_refcount(struct drm_framebuffer *fb)
 267 {
 268         return kref_read(&fb->base.refcount);
 269 }
 270
 271 /**
 272  * drm_framebuffer_assign - store a reference to the fb
 273  * @p: location to store framebuffer
 274  * @fb: new framebuffer (maybe NULL)
 275  *
 276  * This functions sets the location to store a reference to the framebuffer,
 277  * unreferencing the framebuffer that was previously stored in that location.
 278  */
 279 static inline void drm_framebuffer_assign(struct drm_framebuffer **p,
 280                                           struct drm_framebuffer *fb)
 281 {
 282         if (fb)
 283                 drm_framebuffer_get(fb);
 284         if (*p)
 285                 drm_framebuffer_put(*p);
 286         *p = fb;
 287 }
 288
 289 /*
 290  * drm_for_each_fb - iterate over all framebuffers
 291  * @fb: the loop cursor
 292  * @dev: the DRM device
 293  *
 294  * Iterate over all framebuffers of @dev. User must hold
 295  * &drm_mode_config.fb_lock.
 296  */
 297 #define drm_for_each_fb(fb, dev) \
 298         for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),            \
 299              fb = list_first_entry(&(dev)->mode_config.fb_list, \
 300                                           struct drm_framebuffer, head);        \
 301              &fb->head != (&(dev)->mode_config.fb_list);                        \
 302              fb = list_next_entry(fb, head))
 303
 304 int drm_framebuffer_plane_width(int width,
 305                                 const struct drm_framebuffer *fb, int plane);
 306 int drm_framebuffer_plane_height(int height,
 307                                  const struct drm_framebuffer *fb, int plane);
 308
 309 #endif