linux/drivers/thunderbolt/property.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Thunderbolt XDomain property support
 *
 * Copyright (C) 2017, Intel Corporation
 * Authors: Michael Jamet <[email protected]>
 *          Mika Westerberg <[email protected]>
 */

#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uuid.h>
#include <linux/thunderbolt.h>

struct tb_property_entry { … };

struct tb_property_rootdir_entry { … };

struct tb_property_dir_entry { … };

#define TB_PROPERTY_ROOTDIR_MAGIC …

static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
	size_t block_len, unsigned int dir_offset, size_t dir_len,
	bool is_root);

static inline void parse_dwdata(void *dst, const void *src, size_t dwords)
{ … }

static inline void format_dwdata(void *dst, const void *src, size_t dwords)
{ … }

static bool tb_property_entry_valid(const struct tb_property_entry *entry,
				  size_t block_len)
{ … }

static bool tb_property_key_valid(const char *key)
{ … }

static struct tb_property *
tb_property_alloc(const char *key, enum tb_property_type type)
{ … }

static struct tb_property *tb_property_parse(const u32 *block, size_t block_len,
					const struct tb_property_entry *entry)
{ … }

static struct tb_property_dir *__tb_property_parse_dir(const u32 *block,
	size_t block_len, unsigned int dir_offset, size_t dir_len, bool is_root)
{ … }

/**
 * tb_property_parse_dir() - Parses properties from given property block
 * @block: Property block to parse
 * @block_len: Number of dword elements in the property block
 *
 * This function parses the XDomain properties data block into format that
 * can be traversed using the helper functions provided by this module.
 * Upon success returns the parsed directory. In case of error returns
 * %NULL. The resulting &struct tb_property_dir needs to be released by
 * calling tb_property_free_dir() when not needed anymore.
 *
 * The @block is expected to be root directory.
 */
struct tb_property_dir *tb_property_parse_dir(const u32 *block,
					      size_t block_len)
{ … }

/**
 * tb_property_create_dir() - Creates new property directory
 * @uuid: UUID used to identify the particular directory
 *
 * Creates new, empty property directory. If @uuid is %NULL then the
 * directory is assumed to be root directory.
 */
struct tb_property_dir *tb_property_create_dir(const uuid_t *uuid)
{ … }
EXPORT_SYMBOL_GPL(…);

static void tb_property_free(struct tb_property *property)
{ … }

/**
 * tb_property_free_dir() - Release memory allocated for property directory
 * @dir: Directory to release
 *
 * This will release all the memory the directory occupies including all
 * descendants. It is OK to pass %NULL @dir, then the function does
 * nothing.
 */
void tb_property_free_dir(struct tb_property_dir *dir)
{ … }
EXPORT_SYMBOL_GPL(…);

static size_t tb_property_dir_length(const struct tb_property_dir *dir,
				     bool recurse, size_t *data_len)
{ … }

static ssize_t __tb_property_format_dir(const struct tb_property_dir *dir,
	u32 *block, unsigned int start_offset, size_t block_len)
{ … }

/**
 * tb_property_format_dir() - Formats directory to the packed XDomain format
 * @dir: Directory to format
 * @block: Property block where the packed data is placed
 * @block_len: Length of the property block
 *
 * This function formats the directory to the packed format that can be
 * then send over the thunderbolt fabric to receiving host. Returns %0 in
 * case of success and negative errno on faulure. Passing %NULL in @block
 * returns number of entries the block takes.
 */
ssize_t tb_property_format_dir(const struct tb_property_dir *dir, u32 *block,
			       size_t block_len)
{ … }

/**
 * tb_property_copy_dir() - Take a deep copy of directory
 * @dir: Directory to copy
 *
 * This function takes a deep copy of @dir and returns back the copy. In
 * case of error returns %NULL. The resulting directory needs to be
 * released by calling tb_property_free_dir().
 */
struct tb_property_dir *tb_property_copy_dir(const struct tb_property_dir *dir)
{ … }

/**
 * tb_property_add_immediate() - Add immediate property to directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @value: Immediate value to store with the property
 */
int tb_property_add_immediate(struct tb_property_dir *parent, const char *key,
			      u32 value)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tb_property_add_data() - Adds arbitrary data property to directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @buf: Data buffer to add
 * @buflen: Number of bytes in the data buffer
 *
 * Function takes a copy of @buf and adds it to the directory.
 */
int tb_property_add_data(struct tb_property_dir *parent, const char *key,
			 const void *buf, size_t buflen)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tb_property_add_text() - Adds string property to directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @text: String to add
 *
 * Function takes a copy of @text and adds it to the directory.
 */
int tb_property_add_text(struct tb_property_dir *parent, const char *key,
			 const char *text)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tb_property_add_dir() - Adds a directory to the parent directory
 * @parent: Directory to add the property
 * @key: Key for the property
 * @dir: Directory to add
 */
int tb_property_add_dir(struct tb_property_dir *parent, const char *key,
			struct tb_property_dir *dir)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tb_property_remove() - Removes property from a parent directory
 * @property: Property to remove
 *
 * Note memory for @property is released as well so it is not allowed to
 * touch the object after call to this function.
 */
void tb_property_remove(struct tb_property *property)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tb_property_find() - Find a property from a directory
 * @dir: Directory where the property is searched
 * @key: Key to look for
 * @type: Type of the property
 *
 * Finds and returns property from the given directory. Does not recurse
 * into sub-directories. Returns %NULL if the property was not found.
 */
struct tb_property *tb_property_find(struct tb_property_dir *dir,
	const char *key, enum tb_property_type type)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * tb_property_get_next() - Get next property from directory
 * @dir: Directory holding properties
 * @prev: Previous property in the directory (%NULL returns the first)
 */
struct tb_property *tb_property_get_next(struct tb_property_dir *dir,
					 struct tb_property *prev)
{ … }
EXPORT_SYMBOL_GPL(…);