https://github.com/torvalds/linux
Tip revision: b9bbe6ed63b2b9f2c9ee5cbd0f2c946a2723f4ce authored by Linus Torvalds on 17 May 2020, 23:48:37 UTC
Linux 5.7-rc6
Linux 5.7-rc6
Tip revision: b9bbe6e
property.c
// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt XDomain property support
*
* Copyright (C) 2017, Intel Corporation
* Authors: Michael Jamet <michael.jamet@intel.com>
* Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uuid.h>
#include <linux/thunderbolt.h>
struct tb_property_entry {
u32 key_hi;
u32 key_lo;
u16 length;
u8 reserved;
u8 type;
u32 value;
};
struct tb_property_rootdir_entry {
u32 magic;
u32 length;
struct tb_property_entry entries[];
};
struct tb_property_dir_entry {
u32 uuid[4];
struct tb_property_entry entries[];
};
#define TB_PROPERTY_ROOTDIR_MAGIC 0x55584401
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)
{
be32_to_cpu_array(dst, src, dwords);
}
static inline void format_dwdata(void *dst, const void *src, size_t dwords)
{
cpu_to_be32_array(dst, src, dwords);
}
static bool tb_property_entry_valid(const struct tb_property_entry *entry,
size_t block_len)
{
switch (entry->type) {
case TB_PROPERTY_TYPE_DIRECTORY:
case TB_PROPERTY_TYPE_DATA:
case TB_PROPERTY_TYPE_TEXT:
if (entry->length > block_len)
return false;
if (entry->value + entry->length > block_len)
return false;
break;
case TB_PROPERTY_TYPE_VALUE:
if (entry->length != 1)
return false;
break;
}
return true;
}
static bool tb_property_key_valid(const char *key)
{
return key && strlen(key) <= TB_PROPERTY_KEY_SIZE;
}
static struct tb_property *
tb_property_alloc(const char *key, enum tb_property_type type)
{
struct tb_property *property;
property = kzalloc(sizeof(*property), GFP_KERNEL);
if (!property)
return NULL;
strcpy(property->key, key);
property->type = type;
INIT_LIST_HEAD(&property->list);
return property;
}
static struct tb_property *tb_property_parse(const u32 *block, size_t block_len,
const struct tb_property_entry *entry)
{
char key[TB_PROPERTY_KEY_SIZE + 1];
struct tb_property *property;
struct tb_property_dir *dir;
if (!tb_property_entry_valid(entry, block_len))
return NULL;
parse_dwdata(key, entry, 2);
key[TB_PROPERTY_KEY_SIZE] = '\0';
property = tb_property_alloc(key, entry->type);
if (!property)
return NULL;
property->length = entry->length;
switch (property->type) {
case TB_PROPERTY_TYPE_DIRECTORY:
dir = __tb_property_parse_dir(block, block_len, entry->value,
entry->length, false);
if (!dir) {
kfree(property);
return NULL;
}
property->value.dir = dir;
break;
case TB_PROPERTY_TYPE_DATA:
property->value.data = kcalloc(property->length, sizeof(u32),
GFP_KERNEL);
if (!property->value.data) {
kfree(property);
return NULL;
}
parse_dwdata(property->value.data, block + entry->value,
entry->length);
break;
case TB_PROPERTY_TYPE_TEXT:
property->value.text = kcalloc(property->length, sizeof(u32),
GFP_KERNEL);
if (!property->value.text) {
kfree(property);
return NULL;
}
parse_dwdata(property->value.text, block + entry->value,
entry->length);
/* Force null termination */
property->value.text[property->length * 4 - 1] = '\0';
break;
case TB_PROPERTY_TYPE_VALUE:
property->value.immediate = entry->value;
break;
default:
property->type = TB_PROPERTY_TYPE_UNKNOWN;
break;
}
return property;
}
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)
{
const struct tb_property_entry *entries;
size_t i, content_len, nentries;
unsigned int content_offset;
struct tb_property_dir *dir;
dir = kzalloc(sizeof(*dir), GFP_KERNEL);
if (!dir)
return NULL;
if (is_root) {
content_offset = dir_offset + 2;
content_len = dir_len;
} else {
dir->uuid = kmemdup(&block[dir_offset], sizeof(*dir->uuid),
GFP_KERNEL);
if (!dir->uuid) {
tb_property_free_dir(dir);
return NULL;
}
content_offset = dir_offset + 4;
content_len = dir_len - 4; /* Length includes UUID */
}
entries = (const struct tb_property_entry *)&block[content_offset];
nentries = content_len / (sizeof(*entries) / 4);
INIT_LIST_HEAD(&dir->properties);
for (i = 0; i < nentries; i++) {
struct tb_property *property;
property = tb_property_parse(block, block_len, &entries[i]);
if (!property) {
tb_property_free_dir(dir);
return NULL;
}
list_add_tail(&property->list, &dir->properties);
}
return dir;
}
/**
* 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)
{
const struct tb_property_rootdir_entry *rootdir =
(const struct tb_property_rootdir_entry *)block;
if (rootdir->magic != TB_PROPERTY_ROOTDIR_MAGIC)
return NULL;
if (rootdir->length > block_len)
return NULL;
return __tb_property_parse_dir(block, block_len, 0, rootdir->length,
true);
}
/**
* 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)
{
struct tb_property_dir *dir;
dir = kzalloc(sizeof(*dir), GFP_KERNEL);
if (!dir)
return NULL;
INIT_LIST_HEAD(&dir->properties);
if (uuid) {
dir->uuid = kmemdup(uuid, sizeof(*dir->uuid), GFP_KERNEL);
if (!dir->uuid) {
kfree(dir);
return NULL;
}
}
return dir;
}
EXPORT_SYMBOL_GPL(tb_property_create_dir);
static void tb_property_free(struct tb_property *property)
{
switch (property->type) {
case TB_PROPERTY_TYPE_DIRECTORY:
tb_property_free_dir(property->value.dir);
break;
case TB_PROPERTY_TYPE_DATA:
kfree(property->value.data);
break;
case TB_PROPERTY_TYPE_TEXT:
kfree(property->value.text);
break;
default:
break;
}
kfree(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)
{
struct tb_property *property, *tmp;
if (!dir)
return;
list_for_each_entry_safe(property, tmp, &dir->properties, list) {
list_del(&property->list);
tb_property_free(property);
}
kfree(dir->uuid);
kfree(dir);
}
EXPORT_SYMBOL_GPL(tb_property_free_dir);
static size_t tb_property_dir_length(const struct tb_property_dir *dir,
bool recurse, size_t *data_len)
{
const struct tb_property *property;
size_t len = 0;
if (dir->uuid)
len += sizeof(*dir->uuid) / 4;
else
len += sizeof(struct tb_property_rootdir_entry) / 4;
list_for_each_entry(property, &dir->properties, list) {
len += sizeof(struct tb_property_entry) / 4;
switch (property->type) {
case TB_PROPERTY_TYPE_DIRECTORY:
if (recurse) {
len += tb_property_dir_length(
property->value.dir, recurse, data_len);
}
/* Reserve dword padding after each directory */
if (data_len)
*data_len += 1;
break;
case TB_PROPERTY_TYPE_DATA:
case TB_PROPERTY_TYPE_TEXT:
if (data_len)
*data_len += property->length;
break;
default:
break;
}
}
return len;
}
static ssize_t __tb_property_format_dir(const struct tb_property_dir *dir,
u32 *block, unsigned int start_offset, size_t block_len)
{
unsigned int data_offset, dir_end;
const struct tb_property *property;
struct tb_property_entry *entry;
size_t dir_len, data_len = 0;
int ret;
/*
* The structure of property block looks like following. Leaf
* data/text is included right after the directory and each
* directory follows each other (even nested ones).
*
* +----------+ <-- start_offset
* | header | <-- root directory header
* +----------+ ---
* | entry 0 | -^--------------------.
* +----------+ | |
* | entry 1 | -|--------------------|--.
* +----------+ | | |
* | entry 2 | -|-----------------. | |
* +----------+ | | | |
* : : | dir_len | | |
* . . | | | |
* : : | | | |
* +----------+ | | | |
* | entry n | v | | |
* +----------+ <-- data_offset | | |
* | data 0 | <------------------|--' |
* +----------+ | |
* | data 1 | <------------------|-----'
* +----------+ |
* | 00000000 | padding |
* +----------+ <-- dir_end <------'
* | UUID | <-- directory UUID (child directory)
* +----------+
* | entry 0 |
* +----------+
* | entry 1 |
* +----------+
* : :
* . .
* : :
* +----------+
* | entry n |
* +----------+
* | data 0 |
* +----------+
*
* We use dir_end to hold pointer to the end of the directory. It
* will increase as we add directories and each directory should be
* added starting from previous dir_end.
*/
dir_len = tb_property_dir_length(dir, false, &data_len);
data_offset = start_offset + dir_len;
dir_end = start_offset + data_len + dir_len;
if (data_offset > dir_end)
return -EINVAL;
if (dir_end > block_len)
return -EINVAL;
/* Write headers first */
if (dir->uuid) {
struct tb_property_dir_entry *pe;
pe = (struct tb_property_dir_entry *)&block[start_offset];
memcpy(pe->uuid, dir->uuid, sizeof(pe->uuid));
entry = pe->entries;
} else {
struct tb_property_rootdir_entry *re;
re = (struct tb_property_rootdir_entry *)&block[start_offset];
re->magic = TB_PROPERTY_ROOTDIR_MAGIC;
re->length = dir_len - sizeof(*re) / 4;
entry = re->entries;
}
list_for_each_entry(property, &dir->properties, list) {
const struct tb_property_dir *child;
format_dwdata(entry, property->key, 2);
entry->type = property->type;
switch (property->type) {
case TB_PROPERTY_TYPE_DIRECTORY:
child = property->value.dir;
ret = __tb_property_format_dir(child, block, dir_end,
block_len);
if (ret < 0)
return ret;
entry->length = tb_property_dir_length(child, false,
NULL);
entry->value = dir_end;
dir_end = ret;
break;
case TB_PROPERTY_TYPE_DATA:
format_dwdata(&block[data_offset], property->value.data,
property->length);
entry->length = property->length;
entry->value = data_offset;
data_offset += entry->length;
break;
case TB_PROPERTY_TYPE_TEXT:
format_dwdata(&block[data_offset], property->value.text,
property->length);
entry->length = property->length;
entry->value = data_offset;
data_offset += entry->length;
break;
case TB_PROPERTY_TYPE_VALUE:
entry->length = property->length;
entry->value = property->value.immediate;
break;
default:
break;
}
entry++;
}
return dir_end;
}
/**
* 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)
{
ssize_t ret;
if (!block) {
size_t dir_len, data_len = 0;
dir_len = tb_property_dir_length(dir, true, &data_len);
return dir_len + data_len;
}
ret = __tb_property_format_dir(dir, block, 0, block_len);
return ret < 0 ? ret : 0;
}
/**
* 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)
{
struct tb_property *property;
if (!tb_property_key_valid(key))
return -EINVAL;
property = tb_property_alloc(key, TB_PROPERTY_TYPE_VALUE);
if (!property)
return -ENOMEM;
property->length = 1;
property->value.immediate = value;
list_add_tail(&property->list, &parent->properties);
return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_immediate);
/**
* 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)
{
/* Need to pad to dword boundary */
size_t size = round_up(buflen, 4);
struct tb_property *property;
if (!tb_property_key_valid(key))
return -EINVAL;
property = tb_property_alloc(key, TB_PROPERTY_TYPE_DATA);
if (!property)
return -ENOMEM;
property->length = size / 4;
property->value.data = kzalloc(size, GFP_KERNEL);
if (!property->value.data) {
kfree(property);
return -ENOMEM;
}
memcpy(property->value.data, buf, buflen);
list_add_tail(&property->list, &parent->properties);
return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_data);
/**
* 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)
{
/* Need to pad to dword boundary */
size_t size = round_up(strlen(text) + 1, 4);
struct tb_property *property;
if (!tb_property_key_valid(key))
return -EINVAL;
property = tb_property_alloc(key, TB_PROPERTY_TYPE_TEXT);
if (!property)
return -ENOMEM;
property->length = size / 4;
property->value.text = kzalloc(size, GFP_KERNEL);
if (!property->value.text) {
kfree(property);
return -ENOMEM;
}
strcpy(property->value.text, text);
list_add_tail(&property->list, &parent->properties);
return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_text);
/**
* 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)
{
struct tb_property *property;
if (!tb_property_key_valid(key))
return -EINVAL;
property = tb_property_alloc(key, TB_PROPERTY_TYPE_DIRECTORY);
if (!property)
return -ENOMEM;
property->value.dir = dir;
list_add_tail(&property->list, &parent->properties);
return 0;
}
EXPORT_SYMBOL_GPL(tb_property_add_dir);
/**
* 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)
{
list_del(&property->list);
kfree(property);
}
EXPORT_SYMBOL_GPL(tb_property_remove);
/**
* 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)
{
struct tb_property *property;
list_for_each_entry(property, &dir->properties, list) {
if (property->type == type && !strcmp(property->key, key))
return property;
}
return NULL;
}
EXPORT_SYMBOL_GPL(tb_property_find);
/**
* 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)
{
if (prev) {
if (list_is_last(&prev->list, &dir->properties))
return NULL;
return list_next_entry(prev, list);
}
return list_first_entry_or_null(&dir->properties, struct tb_property,
list);
}
EXPORT_SYMBOL_GPL(tb_property_get_next);