linux/include/drm/drm_framebuffer.h

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/*
* Copyright (c) 2016 Intel Corporation
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#ifndef __DRM_FRAMEBUFFER_H__
#define __DRM_FRAMEBUFFER_H__
#include <linux/list.h>
#include <linux/ctype.h>
#include <drm/drm_mode_object.h>
struct drm_framebuffer;
struct drm_file;
struct drm_device;
/**
* struct drm_framebuffer_funcs - framebuffer hooks
*/
struct drm_framebuffer_funcs {
/**
* @destroy:
*
* Clean up framebuffer resources, specifically also unreference the
* backing storage. The core guarantees to call this function for every
* framebuffer successfully created by ->fb_create() in
* &drm_mode_config_funcs. Drivers must also call
* drm_framebuffer_cleanup() to release DRM core resources for this
* framebuffer.
*/
void (*destroy)(struct drm_framebuffer *framebuffer);
/**
* @create_handle:
*
* Create a buffer handle in the driver-specific buffer manager (either
* GEM or TTM) valid for the passed-in struct &drm_file. This is used by
* the core to implement the GETFB IOCTL, which returns (for
* sufficiently priviledged user) also a native buffer handle. This can
* be used for seamless transitions between modesetting clients by
* copying the current screen contents to a private buffer and blending
* between that and the new contents.
*
* GEM based drivers should call drm_gem_handle_create() to create the
* handle.
*
* RETURNS:
*
* 0 on success or a negative error code on failure.
*/
int (*create_handle)(struct drm_framebuffer *fb,
struct drm_file *file_priv,
unsigned int *handle);
/**
* @dirty:
*
* Optional callback for the dirty fb IOCTL.
*
* Userspace can notify the driver via this callback that an area of the
* framebuffer has changed and should be flushed to the display
* hardware. This can also be used internally, e.g. by the fbdev
* emulation, though that's not the case currently.
*
* See documentation in drm_mode.h for the struct drm_mode_fb_dirty_cmd
* for more information as all the semantics and arguments have a one to
* one mapping on this function.
*
* RETURNS:
*
* 0 on success or a negative error code on failure.
*/
int (*dirty)(struct drm_framebuffer *framebuffer,
struct drm_file *file_priv, unsigned flags,
unsigned color, struct drm_clip_rect *clips,
unsigned num_clips);
};
/**
* struct drm_framebuffer - frame buffer object
*
* Note that the fb is refcounted for the benefit of driver internals,
* for example some hw, disabling a CRTC/plane is asynchronous, and
* scanout does not actually complete until the next vblank. So some
* cleanup (like releasing the reference(s) on the backing GEM bo(s))
* should be deferred. In cases like this, the driver would like to
* hold a ref to the fb even though it has already been removed from
* userspace perspective. See drm_framebuffer_reference() and
* drm_framebuffer_unreference().
*
* The refcount is stored inside the mode object @base.
*/
struct drm_framebuffer {
/**
* @dev: DRM device this framebuffer belongs to
*/
struct drm_device *dev;
/**
* @head: Place on the dev->mode_config.fb_list, access protected by
* dev->mode_config.fb_lock.
*/
struct list_head head;
/**
* @base: base modeset object structure, contains the reference count.
*/
struct drm_mode_object base;
/**
* @funcs: framebuffer vfunc table
*/
const struct drm_framebuffer_funcs *funcs;
/**
* @pitches: Line stride per buffer. For userspace created object this
* is copied from drm_mode_fb_cmd2.
*/
unsigned int pitches[4];
/**
* @offsets: Offset from buffer start to the actual pixel data in bytes,
* per buffer. For userspace created object this is copied from
* drm_mode_fb_cmd2.
*
* Note that this is a linear offset and does not take into account
* tiling or buffer laytou per @modifier. It meant to be used when the
* actual pixel data for this framebuffer plane starts at an offset,
* e.g. when multiple planes are allocated within the same backing
* storage buffer object. For tiled layouts this generally means it
* @offsets must at least be tile-size aligned, but hardware often has
* stricter requirements.
*
* This should not be used to specifiy x/y pixel offsets into the buffer
* data (even for linear buffers). Specifying an x/y pixel offset is
* instead done through the source rectangle in struct &drm_plane_state.
*/
unsigned int offsets[4];
/**
* @modifier: Data layout modifier, per buffer. This is used to describe
* tiling, or also special layouts (like compression) of auxiliary
* buffers. For userspace created object this is copied from
* drm_mode_fb_cmd2.
*/
uint64_t modifier[4];
/**
* @width: Logical width of the visible area of the framebuffer, in
* pixels.
*/
unsigned int width;
/**
* @height: Logical height of the visible area of the framebuffer, in
* pixels.
*/
unsigned int height;
/**
* @depth: Depth in bits per pixel for RGB formats. 0 for everything
* else. Legacy information derived from @pixel_format, it's suggested to use
* the DRM FOURCC codes and helper functions directly instead.
*/
unsigned int depth;
/**
* @bits_per_pixel: Storage used bits per pixel for RGB formats. 0 for
* everything else. Legacy information derived from @pixel_format, it's
* suggested to use the DRM FOURCC codes and helper functions directly
* instead.
*/
int bits_per_pixel;
/**
* @flags: Framebuffer flags like DRM_MODE_FB_INTERLACED or
* DRM_MODE_FB_MODIFIERS.
*/
int flags;
/**
* @pixel_format: DRM FOURCC code describing the pixel format.
*/
uint32_t pixel_format; /* fourcc format */
/**
* @hot_x: X coordinate of the cursor hotspot. Used by the legacy cursor
* IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
* universal plane.
*/
int hot_x;
/**
* @hot_y: Y coordinate of the cursor hotspot. Used by the legacy cursor
* IOCTL when the driver supports cursor through a DRM_PLANE_TYPE_CURSOR
* universal plane.
*/
int hot_y;
/**
* @filp_head: Placed on struct &drm_file fbs list_head, protected by
* fbs_lock in the same structure.
*/
struct list_head filp_head;
};
#define obj_to_fb(x) container_of(x, struct drm_framebuffer, base)
int drm_framebuffer_init(struct drm_device *dev,
struct drm_framebuffer *fb,
const struct drm_framebuffer_funcs *funcs);
struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
uint32_t id);
void drm_framebuffer_remove(struct drm_framebuffer *fb);
void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
/**
* drm_framebuffer_reference - incr the fb refcnt
* @fb: framebuffer
*
* This functions increments the fb's refcount.
*/
static inline void drm_framebuffer_reference(struct drm_framebuffer *fb)
{
drm_mode_object_reference(&fb->base);
}
/**
* drm_framebuffer_unreference - unref a framebuffer
* @fb: framebuffer to unref
*
* This functions decrements the fb's refcount and frees it if it drops to zero.
*/
static inline void drm_framebuffer_unreference(struct drm_framebuffer *fb)
{
drm_mode_object_unreference(&fb->base);
}
/**
* drm_framebuffer_read_refcount - read the framebuffer reference count.
* @fb: framebuffer
*
* This functions returns the framebuffer's reference count.
*/
static inline uint32_t drm_framebuffer_read_refcount(struct drm_framebuffer *fb)
{
return atomic_read(&fb->base.refcount.refcount);
}
/**
* drm_for_each_fb - iterate over all framebuffers
* @fb: the loop cursor
* @dev: the DRM device
*
* Iterate over all framebuffers of @dev. User must hold the fb_lock from
* &drm_mode_config.
*/
#define drm_for_each_fb(fb, dev) \
for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.fb_lock)), \
fb = list_first_entry(&(dev)->mode_config.fb_list, \
struct drm_framebuffer, head); \
&fb->head != (&(dev)->mode_config.fb_list); \
fb = list_next_entry(fb, head))
#endif