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Diffstat (limited to 'include/linux/bootconfig.h')
-rw-r--r-- | include/linux/bootconfig.h | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h new file mode 100644 index 000000000..ca73940e2 --- /dev/null +++ b/include/linux/bootconfig.h @@ -0,0 +1,302 @@ +/* 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 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_subkey(NULL, key); +} + +/** + * xbc_node_get_subkey() - Return the first subkey node if exists + * @node: Parent node + * + * Return the first subkey node of the @node. If the @node has no child + * or only value node, this will return NULL. + */ +static inline struct xbc_node * __init xbc_node_get_subkey(struct xbc_node *node) +{ + struct xbc_node *child = xbc_node_get_child(node); + + if (child && xbc_node_is_value(child)) + return xbc_node_get_next(child); + else + return child; +} + +/** + * 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_child(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. + * The @child can be mixture of a value node and subkey nodes. + */ +#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_subkey() - Iterate child subkey nodes + * @parent: An XBC node. + * @child: Iterated XBC node. + * + * Iterate subkey nodes of @parent. Each child nodes are stored to @child. + * The @child is only the subkey node. + */ +#define xbc_node_for_each_subkey(parent, child) \ + for (child = xbc_node_get_subkey(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 stored 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. However, 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_child(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(const char *buf, size_t size, const char **emsg, int *epos); + +/* XBC node and size information */ +int __init xbc_get_info(int *node_size, size_t *data_size); + +/* XBC cleanup data structures */ +void __init xbc_exit(void); + +/* XBC embedded bootconfig data in kernel */ +#ifdef CONFIG_BOOT_CONFIG_EMBED +const char * __init xbc_get_embedded_bootconfig(size_t *size); +#else +static inline const char *xbc_get_embedded_bootconfig(size_t *size) +{ + return NULL; +} +#endif + +#endif |