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 ->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  */
 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 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, per buffer. 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[4];
 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
 211 int drm_framebuffer_init(struct drm_device *dev,
 212                          struct drm_framebuffer *fb,
 213                          const struct drm_framebuffer_funcs *funcs);
 214 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
 215                                                uint32_t id);
 216 void drm_framebuffer_remove(struct drm_framebuffer *fb);
 217 void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
 218 void 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  */
 226 static 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  */
 237 static 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  */
 248 static 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_for_each_fb - iterate over all framebuffers
 255  * @fb: the loop cursor
 256  * @dev: the DRM device
 257  *
 258  * Iterate over all framebuffers of @dev. User must hold the fb_lock from
 259  * &drm_mode_config.
 260  */
 261 #define drm_for_each_fb(fb, dev) \
 262         for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)),            \
 263              fb = list_first_entry(&(dev)->mode_config.fb_list, \
 264                                           struct drm_framebuffer, head);        \
 265              &fb->head != (&(dev)->mode_config.fb_list);                        \
 266              fb = list_next_entry(fb, head))
 267 #endif