/* 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>
*/
#include <linux/kernel.h>
#include <linux/types.h>
#define BOOTCONFIG_MAGIC "#BOOTCONFIG\n"
#define BOOTCONFIG_MAGIC_LEN 12
/* XBC tree node */
struct xbc_node {
u16 next;
u16 child;
u16 parent;
u16 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 1024
#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->next != 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.
*/
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_child(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 value node is stored in *@vnode.
* Note that this can return 0-length string and store NULL in *@vnode for
* key-only (non-value) entry.
*/
static inline const char * __init
xbc_find_value(const char *key, struct xbc_node **vnode)
{
return xbc_node_find_value(NULL, key, vnode);
}
/**
* xbc_find_node() - Find a node which matches the key
* @key: Search key
*
* Search a (key) node whose key matches @key from whole of XBC tree and
* return the node if found. If not found, returns NULL.
*/
static inline struct xbc_node * __init xbc_find_node(const char *key)
{
return xbc_node_find_child(NULL, key);
}
/**
* xbc_array_for_each_value() - Iterate value nodes on an array
* @anode: An XBC arraied value node
* @value: A value
*
* Iterate array value nodes and values starts from @anode. This is expected to
* be used with xbc_find_value() and xbc_node_find_value(), so that user can
* process each array entry node.
*/
#define xbc_array_for_each_value(anode, value) \
for (value = xbc_node_get_data(anode); anode != NULL ; \
anode = xbc_node_get_next(anode), \
value = anode ? xbc_node_get_data(anode) : NULL)
/**
* xbc_node_for_each_child() - Iterate child nodes
* @parent: An XBC node.
* @child: Iterated XBC node.
*
* Iterate child nodes of @parent. Each child nodes are stored to @child.
*/
#define xbc_node_for_each_child(parent, child) \
for (child = xbc_node_get_child(parent); child != NULL ; \
child = xbc_node_get_next(child))
/**
* xbc_node_for_each_array_value() - Iterate array entries of geven key
* @node: An XBC node.
* @key: A key string searched under @node
* @anode: Iterated XBC node of array entry.
* @value: Iterated value of array entry.
*
* Iterate array entries of given @key under @node. Each array entry node
* is stroed to @anode and @value. If the @node doesn't have @key node,
* it does nothing.
* Note that even if the found key node has only one value (not array)
* this executes block once. Hoever, if the found key node has no value
* (key-only node), this does nothing. So don't use this for testing the
* key-value pair existence.
*/
#define xbc_node_for_each_array_value(node, key, anode, value) \
for (value = xbc_node_find_value(node, key, &anode); value != NULL; \
anode = xbc_node_get_next(anode), \
value = anode ? xbc_node_get_data(anode) : NULL)
/**
* xbc_node_for_each_key_value() - Iterate key-value pairs under a node
* @node: An XBC node.
* @knode: Iterated key node
* @value: Iterated value string
*
* Iterate key-value pairs under @node. Each key node and value string are
* stored in @knode and @value respectively.
*/
#define xbc_node_for_each_key_value(node, knode, value) \
for (knode = NULL, value = xbc_node_find_next_key_value(node, &knode);\
knode != NULL; value = xbc_node_find_next_key_value(node, &knode))
/**
* xbc_for_each_key_value() - Iterate key-value pairs
* @knode: Iterated key node
* @value: Iterated value string
*
* Iterate key-value pairs in whole XBC tree. Each key node and value string
* are stored in @knode and @value respectively.
*/
#define xbc_for_each_key_value(knode, value) \
xbc_node_for_each_key_value(NULL, knode, value)
/* Compose partial key */
int __init xbc_node_compose_key_after(struct xbc_node *root,
struct xbc_node *node, char *buf, size_t size);
/**
* xbc_node_compose_key() - Compose full key string of the XBC node
* @node: An XBC node.
* @buf: A buffer to store the key.
* @size: The size of the @buf.
*
* Compose the full-length key of the @node into @buf. Returns the total
* length of the key stored in @buf. Or returns -EINVAL if @node is NULL,
* and -ERANGE if the key depth is deeper than max depth.
*/
static inline int __init xbc_node_compose_key(struct xbc_node *node,
char *buf, size_t size)
{
return xbc_node_compose_key_after(NULL, node, buf, size);
}
/* XBC node initializer */
int __init xbc_init(char *buf, const char **emsg, int *epos);
/* XBC cleanup data structures */
void __init xbc_destroy_all(void);
/* Debug dump functions */
void __init xbc_debug_dump(void);
#endif
