path: root/drivers/gpu/drm/drm_format_helper.c

// SPDX-License-Identifier: GPL-2.0 or MIT
/*
 * Copyright (C) 2016 Noralf Trønnes
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/io.h>
#include <linux/iosys-map.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <drm/drm_device.h>
#include <drm/drm_format_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_print.h>
#include <drm/drm_rect.h>

/**
 * drm_format_conv_state_init - Initialize format-conversion state
 * @state: The state to initialize
 *
 * Clears all fields in struct drm_format_conv_state. The state will
 * be empty with no preallocated resources.
 */
void drm_format_conv_state_init(struct drm_format_conv_state *state)
{
	state->tmp.mem = NULL;
	state->tmp.size = 0;
	state->tmp.preallocated = false;
}
EXPORT_SYMBOL(drm_format_conv_state_init);

/**
 * drm_format_conv_state_copy - Copy format-conversion state
 * @state: Destination state
 * @old_state: Source state
 *
 * Copies format-conversion state from @old_state to @state; except for
 * temporary storage.
 */
void drm_format_conv_state_copy(struct drm_format_conv_state *state,
				const struct drm_format_conv_state *old_state)
{
	/*
	 * So far, there's only temporary storage here, which we don't
	 * duplicate. Just clear the fields.
	 */
	state->tmp.mem = NULL;
	state->tmp.size = 0;
	state->tmp.preallocated = false;
}
EXPORT_SYMBOL(drm_format_conv_state_copy);

/**
 * drm_format_conv_state_reserve - Allocates storage for format conversion
 * @state: The format-conversion state
 * @new_size: The minimum allocation size
 * @flags: Flags for kmalloc()
 *
 * Allocates at least @new_size bytes and returns a pointer to the memory
 * range. After calling this function, previously returned memory blocks
 * are invalid. It's best to collect all memory requirements of a format
 * conversion and call this function once to allocate the range.
 *
 * Returns:
 * A pointer to the allocated memory range, or NULL otherwise.
 */
void *drm_format_conv_state_reserve(struct drm_format_conv_state *state,
				    size_t new_size, gfp_t flags)
{
	void *mem;

	if (new_size <= state->tmp.size)
		goto out;
	else if (state->tmp.preallocated)
		return NULL;

	mem = krealloc(state->tmp.mem, new_size, flags);
	if (!mem)
		return NULL;

	state->tmp.mem = mem;
	state->tmp.size = new_size;

out:
	return state->tmp.mem;
}
EXPORT_SYMBOL(drm_format_conv_state_reserve);

/**
 * drm_format_conv_state_release - Releases an format-conversion storage
 * @state: The format-conversion state
 *
 * Releases the memory range references by the format-conversion state.
 * After this call, all pointers to the memory are invalid. Prefer
 * drm_format_conv_state_init() for cleaning up and unloading a driver.
 */
void drm_format_conv_state_release(struct drm_format_conv_state *state)
{
	if (state->tmp.preallocated)
		return;

	kfree(state->tmp.mem);
	state->tmp.mem = NULL;
	state->tmp.size = 0;
}
EXPORT_SYMBOL(drm_format_conv_state_release);

static unsigned int clip_offset(const struct drm_rect *clip, unsigned int pitch, unsigned int cpp)
{
	return clip->y1 * pitch + clip->x1 * cpp;
}

/**
 * drm_fb_clip_offset - Returns the clipping rectangles byte-offset in a framebuffer
 * @pitch: Framebuffer line pitch in byte
 * @f