/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2014 The ChromiumOS Authors.  All rights reserved.
 *
 * 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; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc.
 */

#include <cbfs.h>
#include <cbmem.h>
#include <console/console.h>
#include <reset.h>
#include <string.h>
#include <vb2_api.h>
#include "../chromeos.h"
#include "../symbols.h"
#include "../vboot_handoff.h"
#include "misc.h"

/*
 * this is placed at the start of the vboot work buffer. selected_region is used
 * for the verstage to return the location of the selected slot. buffer is used
 * by the vboot2 core. Keep the struct cpu architecture agnostic as it crosses
 * stage boundaries.
 */
struct vb2_working_data {
	uint32_t selected_region_offset;
	uint32_t selected_region_size;
	/* offset of the buffer from the start of this struct */
	uint32_t buffer_offset;
	uint32_t buffer_size;
};

static const size_t vb_work_buf_size = 16 * KiB;

static struct vb2_working_data * const vboot_get_working_data(void)
{
	if (IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER))
		/* cbmem_add() does a cbmem_find() first. */
		return cbmem_add(CBMEM_ID_VBOOT_WORKBUF, vb_work_buf_size);
	else
		return (struct vb2_working_data *)_vboot2_work;
}

static size_t vb2_working_data_size(void)
{
	if (IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER))
		return vb_work_buf_size;
	else
		return _vboot2_work_size;
}

void vb2_init_work_context(struct vb2_context *ctx)
{
	struct vb2_working_data *wd;
	size_t work_size;

	/* First initialize the working data region. */
	work_size = vb2_working_data_size();
	wd = vboot_get_working_data();
	memset(wd, 0, work_size);

	/*
	 * vboot prefers 16-byte alignment. This takes away 16 bytes
	 * from the VBOOT2_WORK region, but the vboot devs said that's okay.
	 */
	wd->buffer_offset = ALIGN_UP(sizeof(*wd), 16);
	wd->buffer_size = work_size - wd->buffer_offset;

	/* Initialize the vb2_context. */
	memset(ctx, 0, sizeof(*ctx));
	ctx->workbuf = (void *)vb2_get_shared_data();
	ctx->workbuf_size = wd->buffer_size;

}

struct vb2_shared_data *vb2_get_shared_data(void)
{
	struct vb2_working_data *wd = vboot_get_working_data();
	return (void *)((uintptr_t)wd + wd->buffer_offset);
}

int vb2_get_selected_region(struct region_device *rdev)
{
	const struct vb2_working_data *wd = vboot_get_working_data();
	struct region reg = {
		.offset = wd->selected_region_offset,
		.size = wd->selected_region_size,
	};
	return vboot_region_device(&reg, rdev);
}

void vb2_set_selected_region(struct region_device *rdev)
{
	struct vb2_working_data *wd = vboot_get_working_data();
	wd->selected_region_offset = region_device_offset(rdev);
	wd->selected_region_size = region_device_sz(rdev);
}

int vboot_is_slot_selected(void)
{
	const struct vb2_working_data *wd = vboot_get_working_data();
	return wd->selected_region_size > 0;
}

int vboot_is_readonly_path(void)
{
	return !vboot_is_slot_selected();
}