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  #   ˆl–Ü4ý( ©³( 	Å€fàB¦-ÿÃƒ}¦žÂÁÀ $è    /* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_XBC_H
#define _LINUX_XBC_H
/*
 * Extra Boot Config
 * Copyright (C) 2019 Linaro Ltd.
 * Author: Masami Hiramatsu <mhiramat@kernel.org>
 */

#ifdef __KERNEL__
#include <linux/kernel.h>
#include <linux/types.h>
#else /* !__KERNEL__ */
/*
 * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
 * run the parser sanity test.
 * This does NOT mean linux/bootconfig.h is available in the user space.
 * However, if you change this file, please make sure the tools/bootconfig
 * has no issue on building and running.
 */
#endif

#define BOOTCONFIG_MAGIC	"#BOOTCONFIG\n"
#define BOOTCONFIG_MAGIC_LEN	12
#define BOOTCONFIG_ALIGN_SHIFT	2
#define BOOTCONFIG_ALIGN	(1 << BOOTCONFIG_ALIGN_SHIFT)
#define BOOTCONFIG_ALIGN_MASK	(BOOTCONFIG_ALIGN - 1)

/**
 * xbc_calc_checksum() - Calculate checksum of bootconfig
 * @data: Bootconfig data.
 * @size: The size of the bootconfig data.
 *
 * Calculate the checksum value of the bootconfig data.
 * The checksum will be used with the BOOTCONFIG_MAGIC and the size for
 * embedding the bootconfig in the initrd image.
 */
static inline __init uint32_t xbc_calc_checksum(void *data, uint32_t size)
{
	unsigned char *p = data;
	uint32_t ret = 0;

	while (size--)
		ret += *p++;

	return ret;
}

/* XBC tree node */
struct xbc_node {
	uint16_t next;
	uint16_t child;
	uint16_t parent;
	uint16_t data;
} __attribute__ ((__packed__));

#define XBC_KEY		0
#define XBC_VALUE	(1 << 15)
/* Maximum size of boot config is 32KB - 1 */
#define XBC_DATA_MAX	(XBC_VALUE - 1)

#define XBC_NODE_MAX	8192
#define XBC_KEYLEN_MAX	256
#define XBC_DEPTH_MAX	16

/* Node tree access raw APIs */
struct xbc_node * __init xbc_root_node(void);
int __init xbc_node_index(struct xbc_node *node);
struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node);
struct xbc_node * __init xbc_node_get_child(struct xbc_node *node);
struct xbc_node * __init xbc_node_get_next(struct xbc_node *node);
const char * __init xbc_node_get_data(struct xbc_node *node);

/**
 * xbc_node_is_value() - Test the node is a value node
 * @node: An XBC node.
 *
 * Test the @node is a value node and return true if a value node, false if not.
 */
static inline __init bool xbc_node_is_value(struct xbc_node *node)
{
	return node->data & XBC_VALUE;
}

/**
 * xbc_node_is_key() - Test the node is a key node
 * @node: An XBC node.
 *
 * Test the @node is a key node and return true if a key node, false if not.
 */
static inline __init bool xbc_node_is_key(struct xbc_node *node)
{
	return !xbc_node_is_value(node);
}

/**
 * xbc_node_is_array() - Test the node is an arraied value node
 * @node: An XBC node.
 *
 * Test the @node is an arraied value node.
 */
static inline __init bool xbc_node_is_array(struct xbc_node *node)
{
	return xbc_node_is_value(node) && node->child != 0;
}

/**
 * xbc_node_is_leaf() - Test the node is a leaf key node
 * @node: An XBC node.
 *
 * Test the @node is a leaf key node which is a key node and has a value node
 * or no child. Returns true if it is a leaf node, or false if not.
 * Note that the leaf node can have subkey nodes in addition to the
 * value node.
 */
static inline __init bool xbc_node_is_leaf(struct xbc_node *node)
{
	return xbc_node_is_key(node) &&
		(!node->child || xbc_node_is_value(xbc_node_get_child(node)));
}

/* Tree-based key-value access APIs */
struct xbc_node * __init xbc_node_find_subkey(struct xbc_node *parent,
					     const char *key);

const char * __init xbc_node_find_value(struct xbc_node *parent,
					const char *key,
					struct xbc_node **vnode);

struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,
						 struct xbc_node *leaf);

const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
						 struct xbc_node **leaf);

/**
 * xbc_find_value() - Find a value which matches the key
 * @key: Search key
 * @vnode: A container pointer of XBC value node.
 *
 * Search a value whose key matches @key from whole of XBC tree and return
 * the value if found. Found