linux/drivers/gpu/drm/drm_gem_framebuffer_helper.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * drm gem framebuffer helper functions
 *
 * Copyright (C) 2017 Noralf Trønnes
 */

#include <linux/slab.h>
#include <linux/module.h>

#include <drm/drm_damage_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_modeset_helper.h>

#include "drm_internal.h"

MODULE_IMPORT_NS();

#define AFBC_HEADER_SIZE
#define AFBC_TH_LAYOUT_ALIGNMENT
#define AFBC_HDR_ALIGN
#define AFBC_SUPERBLOCK_PIXELS
#define AFBC_SUPERBLOCK_ALIGNMENT
#define AFBC_TH_BODY_START_ALIGNMENT

/**
 * DOC: overview
 *
 * This library provides helpers for drivers that don't subclass
 * &drm_framebuffer and use &drm_gem_object for their backing storage.
 *
 * Drivers without additional needs to validate framebuffers can simply use
 * drm_gem_fb_create() and everything is wired up automatically. Other drivers
 * can use all parts independently.
 */

/**
 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
 * @fb: Framebuffer
 * @plane: Plane index
 *
 * No additional reference is taken beyond the one that the &drm_frambuffer
 * already holds.
 *
 * Returns:
 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
 * if it does not exist.
 */
struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
					  unsigned int plane)
{}
EXPORT_SYMBOL_GPL();

static int
drm_gem_fb_init(struct drm_device *dev,
		 struct drm_framebuffer *fb,
		 const struct drm_mode_fb_cmd2 *mode_cmd,
		 struct drm_gem_object **obj, unsigned int num_planes,
		 const struct drm_framebuffer_funcs *funcs)
{}

/**
 * drm_gem_fb_destroy - Free GEM backed framebuffer
 * @fb: Framebuffer
 *
 * Frees a GEM backed framebuffer with its backing buffer(s) and the structure
 * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
 * callback.
 */
void drm_gem_fb_destroy(struct drm_framebuffer *fb)
{}
EXPORT_SYMBOL();

/**
 * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
 * @fb: Framebuffer
 * @file: DRM file to register the handle for
 * @handle: Pointer to return the created handle
 *
 * This function creates a handle for the GEM object backing the framebuffer.
 * Drivers can use this as their &drm_framebuffer_funcs->create_handle
 * callback. The GETFB IOCTL calls into this callback.
 *
 * Returns:
 * 0 on success or a negative error code on failure.
 */
int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
			     unsigned int *handle)
{}
EXPORT_SYMBOL();

/**
 * drm_gem_fb_init_with_funcs() - Helper function for implementing
 *				  &drm_mode_config_funcs.fb_create
 *				  callback in cases when the driver
 *				  allocates a subclass of
 *				  struct drm_framebuffer
 * @dev: DRM device
 * @fb: framebuffer object
 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
 * @mode_cmd: Metadata from the userspace framebuffer creation request
 * @funcs: vtable to be used for the new framebuffer object
 *
 * This function can be used to set &drm_framebuffer_funcs for drivers that need
 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
 * change &drm_framebuffer_funcs. The function does buffer size validation.
 * The buffer size validation is for a general case, though, so users should
 * pay attention to the checks being appropriate for them or, at least,
 * non-conflicting.
 *
 * Returns:
 * Zero or a negative error code.
 */
int drm_gem_fb_init_with_funcs(struct drm_device *dev,
			       struct drm_framebuffer *fb,
			       struct drm_file *file,
			       const struct drm_mode_fb_cmd2 *mode_cmd,
			       const struct drm_framebuffer_funcs *funcs)
{}
EXPORT_SYMBOL_GPL();

/**
 * drm_gem_fb_create_with_funcs() - Helper function for the
 *                                  &drm_mode_config_funcs.fb_create
 *                                  callback
 * @dev: DRM device
 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
 * @mode_cmd: Metadata from the userspace framebuffer creation request
 * @funcs: vtable to be used for the new framebuffer object
 *
 * This function can be used to set &drm_framebuffer_funcs for drivers that need
 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
 * change &drm_framebuffer_funcs. The function does buffer size validation.
 *
 * Returns:
 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
 */
struct drm_framebuffer *
drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
			     const struct drm_mode_fb_cmd2 *mode_cmd,
			     const struct drm_framebuffer_funcs *funcs)
{}
EXPORT_SYMBOL_GPL();

static const struct drm_framebuffer_funcs drm_gem_fb_funcs =;

/**
 * drm_gem_fb_create() - Helper function for the
 *                       &drm_mode_config_funcs.fb_create callback
 * @dev: DRM device
 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
 * @mode_cmd: Metadata from the userspace framebuffer creation request
 *
 * This function creates a new framebuffer object described by
 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
 * backing the framebuffer.
 *
 * If your hardware has special alignment or pitch requirements these should be
 * checked before calling this function. The function does buffer size
 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer
 * flushing.
 *
 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
 * The ADDFB2 IOCTL calls into this callback.
 *
 * Returns:
 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
 */
struct drm_framebuffer *
drm_gem_fb_create(struct drm_device *dev, struct drm_file *file,
		  const struct drm_mode_fb_cmd2 *mode_cmd)
{}
EXPORT_SYMBOL_GPL();

static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb =;

/**
 * drm_gem_fb_create_with_dirty() - Helper function for the
 *                       &drm_mode_config_funcs.fb_create callback
 * @dev: DRM device
 * @file: DRM file that holds the GEM handle(s) backing the framebuffer
 * @mode_cmd: Metadata from the userspace framebuffer creation request
 *
 * This function creates a new framebuffer object described by
 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty
 * callback giving framebuffer flushing through the atomic machinery. Use
 * drm_gem_fb_create() if you don't need the dirty callback.
 * The function does buffer size validation.
 *
 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes
 * to enable userspace to use damage clips also with the ATOMIC IOCTL.
 *
 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
 * The ADDFB2 IOCTL calls into this callback.
 *
 * Returns:
 * Pointer to a &drm_framebuffer on success or an error pointer on failure.
 */
struct drm_framebuffer *
drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
			     const struct drm_mode_fb_cmd2 *mode_cmd)
{}
EXPORT_SYMBOL_GPL();

/**
 * drm_gem_fb_vmap - maps all framebuffer BOs into kernel address space
 * @fb: the framebuffer
 * @map: returns the mapping's address for each BO
 * @data: returns the data address for each BO, can be NULL
 *
 * This function maps all buffer objects of the given framebuffer into
 * kernel address space and stores them in struct iosys_map. If the
 * mapping operation fails for one of the BOs, the function unmaps the
 * already established mappings automatically.
 *
 * Callers that want to access a BO's stored data should pass @data.
 * The argument returns the addresses of the data stored in each BO. This
 * is different from @map if the framebuffer's offsets field is non-zero.
 *
 * Both, @map and @data, must each refer to arrays with at least
 * fb->format->num_planes elements.
 *
 * See drm_gem_fb_vunmap() for unmapping.
 *
 * Returns:
 * 0 on success, or a negative errno code otherwise.
 */
int drm_gem_fb_vmap(struct drm_framebuffer *fb, struct iosys_map *map,
		    struct iosys_map *data)
{}
EXPORT_SYMBOL();

/**
 * drm_gem_fb_vunmap - unmaps framebuffer BOs from kernel address space
 * @fb: the framebuffer
 * @map: mapping addresses as returned by drm_gem_fb_vmap()
 *
 * This function unmaps all buffer objects of the given framebuffer.
 *
 * See drm_gem_fb_vmap() for more information.
 */
void drm_gem_fb_vunmap(struct drm_framebuffer *fb, struct iosys_map *map)
{}
EXPORT_SYMBOL();

static void __drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir,
					unsigned int num_planes)
{}

/**
 * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access
 * @fb: the framebuffer
 * @dir: access mode
 *
 * Prepares a framebuffer's GEM buffer objects for CPU access. This function
 * must be called before accessing the BO data within the kernel. For imported
 * BOs, the function calls dma_buf_begin_cpu_access().
 *
 * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access.
 *
 * Returns:
 * 0 on success, or a negative errno code otherwise.
 */
int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
{}
EXPORT_SYMBOL();

/**
 * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects
 * @fb: the framebuffer
 * @dir: access mode
 *
 * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This
 * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access().
 * For imported BOs, the function calls dma_buf_end_cpu_access().
 *
 * See also drm_gem_fb_begin_cpu_access().
 */
void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir)
{}
EXPORT_SYMBOL();

// TODO Drop this function and replace by drm_format_info_bpp() once all
// DRM_FORMAT_* provide proper block info in drivers/gpu/drm/drm_fourcc.c
static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
				  const struct drm_mode_fb_cmd2 *mode_cmd)
{}

static int drm_gem_afbc_min_size(struct drm_device *dev,
				 const struct drm_mode_fb_cmd2 *mode_cmd,
				 struct drm_afbc_framebuffer *afbc_fb)
{}

/**
 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to
 *			    fill and validate all the afbc-specific
 *			    struct drm_afbc_framebuffer members
 *
 * @dev: DRM device
 * @afbc_fb: afbc-specific framebuffer
 * @mode_cmd: Metadata from the userspace framebuffer creation request
 * @afbc_fb: afbc framebuffer
 *
 * This function can be used by drivers which support afbc to complete
 * the preparation of struct drm_afbc_framebuffer. It must be called after
 * allocating the said struct and calling drm_gem_fb_init_with_funcs().
 * It is caller's responsibility to put afbc_fb->base.obj objects in case
 * the call is unsuccessful.
 *
 * Returns:
 * Zero on success or a negative error value on failure.
 */
int drm_gem_fb_afbc_init(struct drm_device *dev,
			 const struct drm_mode_fb_cmd2 *mode_cmd,
			 struct drm_afbc_framebuffer *afbc_fb)
{}
EXPORT_SYMBOL_GPL();