// SPDX-License-Identifier: GPL-2.0+
/*
* Procedures for creating, accessing and interpreting the device tree.
*
* Paul Mackerras August 1996.
* Copyright (C) 1996-2005 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
* {engebret|bergner}@us.ibm.com
*
* Adapted for sparc and sparc64 by David S. Miller [email protected]
*
* Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
* Grant Likely.
*/
#define pr_fmt(fmt) "OF: " fmt
#include <linux/cleanup.h>
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/proc_fs.h>
#include "of_private.h"
LIST_HEAD(aliases_lookup);
struct device_node *of_root;
EXPORT_SYMBOL(of_root);
struct device_node *of_chosen;
EXPORT_SYMBOL(of_chosen);
struct device_node *of_aliases;
struct device_node *of_stdout;
static const char *of_stdout_options;
struct kset *of_kset;
/*
* Used to protect the of_aliases, to hold off addition of nodes to sysfs.
* This mutex must be held whenever modifications are being made to the
* device tree. The of_{attach,detach}_node() and
* of_{add,remove,update}_property() helpers make sure this happens.
*/
DEFINE_MUTEX(of_mutex);
/* use when traversing tree through the child, sibling,
* or parent members of struct device_node.
*/
DEFINE_RAW_SPINLOCK(devtree_lock);
bool of_node_name_eq(const struct device_node *np, const char *name)
{
const char *node_name;
size_t len;
if (!np)
return false;
node_name = kbasename(np->full_name);
len = strchrnul(node_name, '@') - node_name;
return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
}
EXPORT_SYMBOL(of_node_name_eq);
bool of_node_name_prefix(const struct device_node *np, const char *prefix)
{
if (!np)
return false;
return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
}
EXPORT_SYMBOL(of_node_name_prefix);
static bool __of_node_is_type(const struct device_node *np, const char *type)
{
const char *match = __of_get_property(np, "device_type", NULL);
return np && match && type && !strcmp(match, type);
}
int of_bus_n_addr_cells(struct device_node *np)
{
u32 cells;
for (; np; np = np->parent)
if (!of_property_read_u32(np, "#address-cells", &cells))
return cells;
/* No #address-cells property for the root node */
return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
}
int of_n_addr_cells(struct device_node *np)
{
if (np->parent)
np = np->parent;
return of_bus_n_addr_cells(np);
}
EXPORT_SYMBOL(of_n_addr_cells);
int of_bus_n_size_cells(struct device_node *np)
{
u32 cells;
for (; np; np = np->parent)
if (!of_property_read_u32(np, "#size-cells", &cells))
return cells;
/* No #size-cells property for the root node */
return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
}
int of_n_size_cells(struct device_node *np)
{
if (np->parent)
np = np->parent;
return of_bus_n_size_cells(np);
}
EXPORT_SYMBOL(of_n_size_cells);
#ifdef CONFIG_NUMA
int __weak of_node_to_nid(struct device_node *np)
{
return NUMA_NO_NODE;
}
#endif
#define OF_PHANDLE_CACHE_BITS 7
#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
static u32 of_phandle_cache_hash(phandle handle)
{
return hash_32(handle, OF_PHANDLE_CACHE_BITS);
}
/*
* Caller must hold devtree_lock.
*/
void __of_phandle_cache_inv_entry(phandle handle)
{
u32 handle_hash;
struct device_node *np;
if (!handle)
return;
handle_hash = of_phandle_cache_hash(handle);
np = phandle_cache[handle_hash];
if (np && handle == np->phandle)
phandle_cache[handle_hash] = NULL;
}
void __init of_core_init(void)
{
struct device_node *np;
of_platform_register_reconfig_notifier();
/* Create the kset, and register existing nodes */
mutex_lock(&of_mutex);
of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
if (!of_kset) {
mutex_unlock(&of_mutex);
pr_err("failed to register existing nodes\n");
return;
}
for_each_of_allnodes(np) {
__of_attach_node_sysfs(np);
if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
}
mutex_unlock(&of_mutex);
/* Symlink in /proc as required by userspace ABI */
if (of_root)
proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
}
static struct property *__of_find_property(const struct device_node *np,
const char *name, int *lenp)
{
struct property *pp;
if (!np)
return NULL;
for (pp = np->properties; pp; pp = pp->next) {
if (of_prop_cmp(pp->name, name) == 0) {
if (lenp)
*lenp = pp->length;
break;
}
}
return pp;
}
struct property *of_find_property(const struct device_node *np,
const char *name,
int *lenp)
{
struct property *pp;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
pp = __of_find_property(np, name, lenp);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return pp;
}
EXPORT_SYMBOL(of_find_property);
struct device_node *__of_find_all_nodes(struct device_node *prev)
{
struct device_node *np;
if (!prev) {
np = of_root;
} else if (prev->child) {
np = prev->child;
} else {
/* Walk back up looking for a sibling, or the end of the structure */
np = prev;
while (np->parent && !np->sibling)
np = np->parent;
np = np->sibling; /* Might be null at the end of the tree */
}
return np;
}
/**
* of_find_all_nodes - Get next node in global list
* @prev: Previous node or NULL to start iteration
* of_node_put() will be called on it
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_all_nodes(struct device_node *prev)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
np = __of_find_all_nodes(prev);
of_node_get(np);
of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_all_nodes);
/*
* Find a property with a given name for a given node
* and return the value.
*/
const void *__of_get_property(const struct device_node *np,
const char *name, int *lenp)
{
struct property *pp = __of_find_property(np, name, lenp);
return pp ? pp->value : NULL;
}
/*
* Find a property with a given name for a given node
* and return the value.
*/
const void *of_get_property(const struct device_node *np, const char *name,
int *lenp)
{
struct property *pp = of_find_property(np, name, lenp);
return pp ? pp->value : NULL;
}
EXPORT_SYMBOL(of_get_property);
/**
* __of_device_is_compatible() - Check if the node matches given constraints
* @device: pointer to node
* @compat: required compatible string, NULL or "" for any match
* @type: required device_type value, NULL or "" for any match
* @name: required node name, NULL or "" for any match
*
* Checks if the given @compat, @type and @name strings match the
* properties of the given @device. A constraints can be skipped by
* passing NULL or an empty string as the constraint.
*
* Returns 0 for no match, and a positive integer on match. The return
* value is a relative score with larger values indicating better
* matches. The score is weighted for the most specific compatible value
* to get the highest score. Matching type is next, followed by matching
* name. Practically speaking, this results in the following priority
* order for matches:
*
* 1. specific compatible && type && name
* 2. specific compatible && type
* 3. specific compatible && name
* 4. specific compatible
* 5. general compatible && type && name
* 6. general compatible && type
* 7. general compatible && name
* 8. general compatible
* 9. type && name
* 10. type
* 11. name
*/
static int __of_device_is_compatible(const struct device_node *device,
const char *compat, const char *type, const char *name)
{
struct property *prop;
const char *cp;
int index = 0, score = 0;
/* Compatible match has highest priority */
if (compat && compat[0]) {
prop = __of_find_property(device, "compatible", NULL);
for (cp = of_prop_next_string(prop, NULL); cp;
cp = of_prop_next_string(prop, cp), index++) {
if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
score = INT_MAX/2 - (index << 2);
break;
}
}
if (!score)
return 0;
}
/* Matching type is better than matching name */
if (type && type[0]) {
if (!__of_node_is_type(device, type))
return 0;
score += 2;
}
/* Matching name is a bit better than not */
if (name && name[0]) {
if (!of_node_name_eq(device, name))
return 0;
score++;
}
return score;
}
/** Checks if the given "compat" string matches one of the strings in
* the device's "compatible" property
*/
int of_device_is_compatible(const struct device_node *device,
const char *compat)
{
unsigned long flags;
int res;
raw_spin_lock_irqsave(&devtree_lock, flags);
res = __of_device_is_compatible(device, compat, NULL, NULL);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return res;
}
EXPORT_SYMBOL(of_device_is_compatible);
/** Checks if the device is compatible with any of the entries in
* a NULL terminated array of strings. Returns the best match
* score or 0.
*/
int of_device_compatible_match(const struct device_node *device,
const char *const *compat)
{
unsigned int tmp, score = 0;
if (!compat)
return 0;
while (*compat) {
tmp = of_device_is_compatible(device, *compat);
if (tmp > score)
score = tmp;
compat++;
}
return score;
}
EXPORT_SYMBOL_GPL(of_device_compatible_match);
/**
* of_machine_compatible_match - Test root of device tree against a compatible array
* @compats: NULL terminated array of compatible strings to look for in root node's compatible property.
*
* Returns true if the root node has any of the given compatible values in its
* compatible property.
*/
bool of_machine_compatible_match(const char *const *compats)
{
struct device_node *root;
int rc = 0;
root = of_find_node_by_path("/");
if (root) {
rc = of_device_compatible_match(root, compats);
of_node_put(root);
}
return rc != 0;
}
EXPORT_SYMBOL(of_machine_compatible_match);
static bool __of_device_is_status(const struct device_node *device,
const char * const*strings)
{
const char *status;
int statlen;
if (!device)
return false;
status = __of_get_property(device, "status", &statlen);
if (status == NULL)
return false;
if (statlen > 0) {
while (*strings) {
unsigned int len = strlen(*strings);
if ((*strings)[len - 1] == '-') {
if (!strncmp(status, *strings, len))
return true;
} else {
if (!strcmp(status, *strings))
return true;
}
strings++;
}
}
return false;
}
/**
* __of_device_is_available - check if a device is available for use
*
* @device: Node to check for availability, with locks already held
*
* Return: True if the status property is absent or set to "okay" or "ok",
* false otherwise
*/
static bool __of_device_is_available(const struct device_node *device)
{
static const char * const ok[] = {"okay", "ok", NULL};
if (!device)
return false;
return !__of_get_property(device, "status", NULL) ||
__of_device_is_status(device, ok);
}
/**
* __of_device_is_reserved - check if a device is reserved
*
* @device: Node to check for availability, with locks already held
*
* Return: True if the status property is set to "reserved", false otherwise
*/
static bool __of_device_is_reserved(const struct device_node *device)
{
static const char * const reserved[] = {"reserved", NULL};
return __of_device_is_status(device, reserved);
}
/**
* of_device_is_available - check if a device is available for use
*
* @device: Node to check for availability
*
* Return: True if the status property is absent or set to "okay" or "ok",
* false otherwise
*/
bool of_device_is_available(const struct device_node *device)
{
unsigned long flags;
bool res;
raw_spin_lock_irqsave(&devtree_lock, flags);
res = __of_device_is_available(device);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return res;
}
EXPORT_SYMBOL(of_device_is_available);
/**
* __of_device_is_fail - check if a device has status "fail" or "fail-..."
*
* @device: Node to check status for, with locks already held
*
* Return: True if the status property is set to "fail" or "fail-..." (for any
* error code suffix), false otherwise
*/
static bool __of_device_is_fail(const struct device_node *device)
{
static const char * const fail[] = {"fail", "fail-", NULL};
return __of_device_is_status(device, fail);
}
/**
* of_device_is_big_endian - check if a device has BE registers
*
* @device: Node to check for endianness
*
* Return: True if the device has a "big-endian" property, or if the kernel
* was compiled for BE *and* the device has a "native-endian" property.
* Returns false otherwise.
*
* Callers would nominally use ioread32be/iowrite32be if
* of_device_is_big_endian() == true, or readl/writel otherwise.
*/
bool of_device_is_big_endian(const struct device_node *device)
{
if (of_property_read_bool(device, "big-endian"))
return true;
if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
of_property_read_bool(device, "native-endian"))
return true;
return false;
}
EXPORT_SYMBOL(of_device_is_big_endian);
/**
* of_get_parent - Get a node's parent if any
* @node: Node to get parent
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_get_parent(const struct device_node *node)
{
struct device_node *np;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
np = of_node_get(node->parent);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_get_parent);
/**
* of_get_next_parent - Iterate to a node's parent
* @node: Node to get parent of
*
* This is like of_get_parent() except that it drops the
* refcount on the passed node, making it suitable for iterating
* through a node's parents.
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_get_next_parent(struct device_node *node)
{
struct device_node *parent;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
parent = of_node_get(node->parent);
of_node_put(node);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return parent;
}
EXPORT_SYMBOL(of_get_next_parent);
static struct device_node *__of_get_next_child(const struct device_node *node,
struct device_node *prev)
{
struct device_node *next;
if (!node)
return NULL;
next = prev ? prev->sibling : node->child;
of_node_get(next);
of_node_put(prev);
return next;
}
#define __for_each_child_of_node(parent, child) \
for (child = __of_get_next_child(parent, NULL); child != NULL; \
child = __of_get_next_child(parent, child))
/**
* of_get_next_child - Iterate a node childs
* @node: parent node
* @prev: previous child of the parent node, or NULL to get first
*
* Return: A node pointer with refcount incremented, use of_node_put() on
* it when done. Returns NULL when prev is the last child. Decrements the
* refcount of prev.
*/
struct device_node *of_get_next_child(const struct device_node *node,
struct device_node *prev)
{
struct device_node *next;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
next = __of_get_next_child(node, prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
EXPORT_SYMBOL(of_get_next_child);
static struct device_node *of_get_next_status_child(const struct device_node *node,
struct device_node *prev,
bool (*checker)(const struct device_node *))
{
struct device_node *next;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
next = prev ? prev->sibling : node->child;
for (; next; next = next->sibling) {
if (!checker(next))
continue;
if (of_node_get(next))
break;
}
of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
/**
* of_get_next_available_child - Find the next available child node
* @node: parent node
* @prev: previous child of the parent node, or NULL to get first
*
* This function is like of_get_next_child(), except that it
* automatically skips any disabled nodes (i.e. status = "disabled").
*/
struct device_node *of_get_next_available_child(const struct device_node *node,
struct device_node *prev)
{
return of_get_next_status_child(node, prev, __of_device_is_available);
}
EXPORT_SYMBOL(of_get_next_available_child);
/**
* of_get_next_reserved_child - Find the next reserved child node
* @node: parent node
* @prev: previous child of the parent node, or NULL to get first
*
* This function is like of_get_next_child(), except that it
* automatically skips any disabled nodes (i.e. status = "disabled").
*/
struct device_node *of_get_next_reserved_child(const struct device_node *node,
struct device_node *prev)
{
return of_get_next_status_child(node, prev, __of_device_is_reserved);
}
EXPORT_SYMBOL(of_get_next_reserved_child);
/**
* of_get_next_cpu_node - Iterate on cpu nodes
* @prev: previous child of the /cpus node, or NULL to get first
*
* Unusable CPUs (those with the status property set to "fail" or "fail-...")
* will be skipped.
*
* Return: A cpu node pointer with refcount incremented, use of_node_put()
* on it when done. Returns NULL when prev is the last child. Decrements
* the refcount of prev.
*/
struct device_node *of_get_next_cpu_node(struct device_node *prev)
{
struct device_node *next = NULL;
unsigned long flags;
struct device_node *node;
if (!prev)
node = of_find_node_by_path("/cpus");
raw_spin_lock_irqsave(&devtree_lock, flags);
if (prev)
next = prev->sibling;
else if (node) {
next = node->child;
of_node_put(node);
}
for (; next; next = next->sibling) {
if (__of_device_is_fail(next))
continue;
if (!(of_node_name_eq(next, "cpu") ||
__of_node_is_type(next, "cpu")))
continue;
if (of_node_get(next))
break;
}
of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
EXPORT_SYMBOL(of_get_next_cpu_node);
/**
* of_get_compatible_child - Find compatible child node
* @parent: parent node
* @compatible: compatible string
*
* Lookup child node whose compatible property contains the given compatible
* string.
*
* Return: a node pointer with refcount incremented, use of_node_put() on it
* when done; or NULL if not found.
*/
struct device_node *of_get_compatible_child(const struct device_node *parent,
const char *compatible)
{
struct device_node *child;
for_each_child_of_node(parent, child) {
if (of_device_is_compatible(child, compatible))
break;
}
return child;
}
EXPORT_SYMBOL(of_get_compatible_child);
/**
* of_get_child_by_name - Find the child node by name for a given parent
* @node: parent node
* @name: child name to look for.
*
* This function looks for child node for given matching name
*
* Return: A node pointer if found, with refcount incremented, use
* of_node_put() on it when done.
* Returns NULL if node is not found.
*/
struct device_node *of_get_child_by_name(const struct device_node *node,
const char *name)
{
struct device_node *child;
for_each_child_of_node(node, child)
if (of_node_name_eq(child, name))
break;
return child;
}
EXPORT_SYMBOL(of_get_child_by_name);
struct device_node *__of_find_node_by_path(struct device_node *parent,
const char *path)
{
struct device_node *child;
int len;
len = strcspn(path, "/:");
if (!len)
return NULL;
__for_each_child_of_node(parent, child) {
const char *name = kbasename(child->full_name);
if (strncmp(path, name, len) == 0 && (strlen(name) == len))
return child;
}
return NULL;
}
struct device_node *__of_find_node_by_full_path(struct device_node *node,
const char *path)
{
const char *separator = strchr(path, ':');
while (node && *path == '/') {
struct device_node *tmp = node;
path++; /* Increment past '/' delimiter */
node = __of_find_node_by_path(node, path);
of_node_put(tmp);
path = strchrnul(path, '/');
if (separator && separator < path)
break;
}
return node;
}
/**
* of_find_node_opts_by_path - Find a node matching a full OF path
* @path: Either the full path to match, or if the path does not
* start with '/', the name of a property of the /aliases
* node (an alias). In the case of an alias, the node
* matching the alias' value will be returned.
* @opts: Address of a pointer into which to store the start of
* an options string appended to the end of the path with
* a ':' separator.
*
* Valid paths:
* * /foo/bar Full path
* * foo Valid alias
* * foo/bar Valid alias + relative path
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
{
struct device_node *np = NULL;
struct property *pp;
unsigned long flags;
const char *separator = strchr(path, ':');
if (opts)
*opts = separator ? separator + 1 : NULL;
if (strcmp(path, "/") == 0)
return of_node_get(of_root);
/* The path could begin with an alias */
if (*path != '/') {
int len;
const char *p = separator;
if (!p)
p = strchrnul(path, '/');
len = p - path;
/* of_aliases must not be NULL */
if (!of_aliases)
return NULL;
for_each_property_of_node(of_aliases, pp) {
if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
np = of_find_node_by_path(pp->value);
break;
}
}
if (!np)
return NULL;
path = p;
}
/* Step down the tree matching path components */
raw_spin_lock_irqsave(&devtree_lock, flags);
if (!np)
np = of_node_get(of_root);
np = __of_find_node_by_full_path(np, path);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_opts_by_path);
/**
* of_find_node_by_name - Find a node by its "name" property
* @from: The node to start searching from or NULL; the node
* you pass will not be searched, only the next one
* will. Typically, you pass what the previous call
* returned. of_node_put() will be called on @from.
* @name: The name string to match against
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_by_name(struct device_node *from,
const char *name)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np)
if (of_node_name_eq(np, name) && of_node_get(np))
break;
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_name);
/**
* of_find_node_by_type - Find a node by its "device_type" property
* @from: The node to start searching from, or NULL to start searching
* the entire device tree. The node you pass will not be
* searched, only the next one will; typically, you pass
* what the previous call returned. of_node_put() will be
* called on from for you.
* @type: The type string to match against
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_by_type(struct device_node *from,
const char *type)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np)
if (__of_node_is_type(np, type) && of_node_get(np))
break;
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_type);
/**
* of_find_compatible_node - Find a node based on type and one of the
* tokens in its "compatible" property
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @type: The type string to match "device_type" or NULL to ignore
* @compatible: The string to match to one of the tokens in the device
* "compatible" list.
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_compatible_node(struct device_node *from,
const char *type, const char *compatible)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np)
if (__of_device_is_compatible(np, compatible, type, NULL) &&
of_node_get(np))
break;
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_compatible_node);
/**
* of_find_node_with_property - Find a node which has a property with
* the given name.
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @prop_name: The name of the property to look for.
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_with_property(struct device_node *from,
const char *prop_name)
{
struct device_node *np;
struct property *pp;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np) {
for (pp = np->properties; pp; pp = pp->next) {
if (of_prop_cmp(pp->name, prop_name) == 0) {
of_node_get(np);
goto out;
}
}
}
out:
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_with_property);
static
const struct of_device_id *__of_match_node(const struct of_device_id *matches,
const struct device_node *node)
{
const struct of_device_id *best_match = NULL;
int score, best_score = 0;
if (!matches)
return NULL;
for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
score = __of_device_is_compatible(node, matches->compatible,
matches->type, matches->name);
if (score > best_score) {
best_match = matches;
best_score = score;
}
}
return best_match;
}
/**
* of_match_node - Tell if a device_node has a matching of_match structure
* @matches: array of of device match structures to search in
* @node: the of device structure to match against
*
* Low level utility function used by device matching.
*/
const struct of_device_id *of_match_node(const struct of_device_id *matches,
const struct device_node *node)
{
const struct of_device_id *match;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
match = __of_match_node(matches, node);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return match;
}
EXPORT_SYMBOL(of_match_node);
/**
* of_find_matching_node_and_match - Find a node based on an of_device_id
* match table.
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @matches: array of of device match structures to search in
* @match: Updated to point at the matches entry which matched
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_matching_node_and_match(struct device_node *from,
const struct of_device_id *matches,
const struct of_device_id **match)
{
struct device_node *np;
const struct of_device_id *m;
unsigned long flags;
if (match)
*match = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np) {
m = __of_match_node(matches, np);
if (m && of_node_get(np)) {
if (match)
*match = m;
break;
}
}
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_matching_node_and_match);
/**
* of_alias_from_compatible - Lookup appropriate alias for a device node
* depending on compatible
* @node: pointer to a device tree node
* @alias: Pointer to buffer that alias value will be copied into
* @len: Length of alias value
*
* Based on the value of the compatible property, this routine will attempt
* to choose an appropriate alias value for a particular device tree node.
* It does this by stripping the manufacturer prefix (as delimited by a ',')
* from the first entry in the compatible list property.
*
* Note: The matching on just the "product" side of the compatible is a relic
* from I2C and SPI. Please do not add any new user.
*
* Return: This routine returns 0 on success, <0 on failure.
*/
int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
{
const char *compatible, *p;
int cplen;
compatible = of_get_property(node, "compatible", &cplen);
if (!compatible || strlen(compatible) > cplen)
return -ENODEV;
p = strchr(compatible, ',');
strscpy(alias, p ? p + 1 : compatible, len);
return 0;
}
EXPORT_SYMBOL_GPL(of_alias_from_compatible);
/**
* of_find_node_by_phandle - Find a node given a phandle
* @handle: phandle of the node to find
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_by_phandle(phandle handle)
{
struct device_node *np = NULL;
unsigned long flags;
u32 handle_hash;
if (!handle)
return NULL;
handle_hash = of_phandle_cache_hash(handle);
raw_spin_lock_irqsave(&devtree_lock, flags);
if (phandle_cache[handle_hash] &&
handle == phandle_cache[handle_hash]->phandle)
np = phandle_cache[handle_hash];
if (!np) {
for_each_of_allnodes(np)
if (np->phandle == handle &&
!of_node_check_flag(np, OF_DETACHED)) {
phandle_cache[handle_hash] = np;
break;
}
}
of_node_get(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_phandle);
void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
{
int i;
printk("%s %pOF", msg, args->np);
for (i = 0; i < args->args_count; i++) {
const char delim = i ? ',' : ':';
pr_cont("%c%08x", delim, args->args[i]);
}
pr_cont("\n");
}
int of_phandle_iterator_init(struct of_phandle_iterator *it,
const struct device_node *np,
const char *list_name,
const char *cells_name,
int cell_count)
{
const __be32 *list;
int size;
memset(it, 0, sizeof(*it));
/*
* one of cell_count or cells_name must be provided to determine the
* argument length.
*/
if (cell_count < 0 && !cells_name)
return -EINVAL;
list = of_get_property(np, list_name, &size);
if (!list)
return -ENOENT;
it->cells_name = cells_name;
it->cell_count = cell_count;
it->parent = np;
it->list_end = list + size / sizeof(*list);
it->phandle_end = list;
it->cur = list;
return 0;
}
EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
int of_phandle_iterator_next(struct of_phandle_iterator *it)
{
uint32_t count = 0;
if (it->node) {
of_node_put(it->node);
it->node = NULL;
}
if (!it->cur || it->phandle_end >= it->list_end)
return -ENOENT;
it->cur = it->phandle_end;
/* If phandle is 0, then it is an empty entry with no arguments. */
it->phandle = be32_to_cpup(it->cur++);
if (it->phandle) {
/*
* Find the provider node and parse the #*-cells property to
* determine the argument length.
*/
it->node = of_find_node_by_phandle(it->phandle);
if (it->cells_name) {
if (!it->node) {
pr_err("%pOF: could not find phandle %d\n",
it->parent, it->phandle);
goto err;
}
if (of_property_read_u32(it->node, it->cells_name,
&count)) {
/*
* If both cell_count and cells_name is given,
* fall back to cell_count in absence
* of the cells_name property
*/
if (it->cell_count >= 0) {
count = it->cell_count;
} else {
pr_err("%pOF: could not get %s for %pOF\n",
it->parent,
it->cells_name,
it->node);
goto err;
}
}
} else {
count = it->cell_count;
}
/*
* Make sure that the arguments actually fit in the remaining
* property data length
*/
if (it->cur + count > it->list_end) {
if (it->cells_name)
pr_err("%pOF: %s = %d found %td\n",
it->parent, it->cells_name,
count, it->list_end - it->cur);
else
pr_err("%pOF: phandle %s needs %d, found %td\n",
it->parent, of_node_full_name(it->node),
count, it->list_end - it->cur);
goto err;
}
}
it->phandle_end = it->cur + count;
it->cur_count = count;
return 0;
err:
if (it->node) {
of_node_put(it->node);
it->node = NULL;
}
return -EINVAL;
}
EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
int of_phandle_iterator_args(struct of_phandle_iterator *it,
uint32_t *args,
int size)
{
int i, count;
count = it->cur_count;
if (WARN_ON(size < count))
count = size;
for (i = 0; i < count; i++)
args[i] = be32_to_cpup(it->cur++);
return count;
}
int __of_parse_phandle_with_args(const struct device_node *np,
const char *list_name,
const char *cells_name,
int cell_count, int index,
struct of_phandle_args *out_args)
{
struct of_phandle_iterator it;
int rc, cur_index = 0;
if (index < 0)
return -EINVAL;
/* Loop over the phandles until all the requested entry is found */
of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
/*
* All of the error cases bail out of the loop, so at
* this point, the parsing is successful. If the requested
* index matches, then fill the out_args structure and return,
* or return -ENOENT for an empty entry.
*/
rc = -ENOENT;
if (cur_index == index) {
if (!it.phandle)
goto err;
if (out_args) {
int c;
c = of_phandle_iterator_args(&it,
out_args->args,
MAX_PHANDLE_ARGS);
out_args->np = it.node;
out_args->args_count = c;
} else {
of_node_put(it.node);
}
/* Found it! return success */
return 0;
}
cur_index++;
}
/*
* Unlock node before returning result; will be one of:
* -ENOENT : index is for empty phandle
* -EINVAL : parsing error on data
*/
err:
of_node_put(it.node);
return rc;
}
EXPORT_SYMBOL(__of_parse_phandle_with_args);
/**
* of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
* @np: pointer to a device tree node containing a list
* @list_name: property name that contains a list
* @stem_name: stem of property names that specify phandles' arguments count
* @index: index of a phandle to parse out
* @out_args: optional pointer to output arguments structure (will be filled)
*
* This function is useful to parse lists of phandles and their arguments.
* Returns 0 on success and fills out_args, on error returns appropriate errno
* value. The difference between this function and of_parse_phandle_with_args()
* is that this API remaps a phandle if the node the phandle points to has
* a <@stem_name>-map property.
*
* Caller is responsible to call of_node_put() on the returned out_args->np
* pointer.
*
* Example::
*
* phandle1: node1 {
* #list-cells = <2>;
* };
*
* phandle2: node2 {
* #list-cells = <1>;
* };
*
* phandle3: node3 {
* #list-cells = <1>;
* list-map = <0 &phandle2 3>,
* <1 &phandle2 2>,
* <2 &phandle1 5 1>;
* list-map-mask = <0x3>;
* };
*
* node4 {
* list = <&phandle1 1 2 &phandle3 0>;
* };
*
* To get a device_node of the ``node2`` node you may call this:
* of_parse_phandle_with_args(node4, "list", "list", 1, &args);
*/
int of_parse_phandle_with_args_map(const struct device_node *np,
const char *list_name,
const char *stem_name,
int index, struct of_phandle_args *out_args)
{
char *cells_name __free(kfree) = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
char *map_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map", stem_name);
char *mask_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
char *pass_name __free(kfree) = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
struct device_node *cur, *new = NULL;
const __be32 *map, *mask, *pass;
static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(0) };
__be32 initial_match_array[MAX_PHANDLE_ARGS];
const __be32 *match_array = initial_match_array;
int i, ret, map_len, match;
u32 list_size, new_size;
if (index < 0)
return -EINVAL;
if (!cells_name || !map_name || !mask_name || !pass_name)
return -ENOMEM;
ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
out_args);
if (ret)
return ret;
/* Get the #<list>-cells property */
cur = out_args->np;
ret = of_property_read_u32(cur, cells_name, &list_size);
if (ret < 0)
goto put;
/* Precalculate the match array - this simplifies match loop */
for (i = 0; i < list_size; i++)
initial_match_array[i] = cpu_to_be32(out_args->args[i]);
ret = -EINVAL;
while (cur) {
/* Get the <list>-map property */
map = of_get_property(cur, map_name, &map_len);
if (!map) {
return 0;
}
map_len /= sizeof(u32);
/* Get the <list>-map-mask property (optional) */
mask = of_get_property(cur, mask_name, NULL);
if (!mask)
mask = dummy_mask;
/* Iterate through <list>-map property */
match = 0;
while (map_len > (list_size + 1) && !match) {
/* Compare specifiers */
match = 1;
for (i = 0; i < list_size; i++, map_len--)
match &= !((match_array[i] ^ *map++) & mask[i]);
of_node_put(new);
new = of_find_node_by_phandle(be32_to_cpup(map));
map++;
map_len--;
/* Check if not found */
if (!new)
goto put;
if (!of_device_is_available(new))
match = 0;
ret = of_property_read_u32(new, cells_name, &new_size);
if (ret)
goto put;
/* Check for malformed properties */
if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
goto put;
if (map_len < new_size)
goto put;
/* Move forward by new node's #<list>-cells amount */
map += new_size;
map_len -= new_size;
}
if (!match)
goto put;
/* Get the <list>-map-pass-thru property (optional) */
pass = of_get_property(cur, pass_name, NULL);
if (!pass)
pass = dummy_pass;
/*
* Successfully parsed a <list>-map translation; copy new
* specifier into the out_args structure, keeping the
* bits specified in <list>-map-pass-thru.
*/
match_array = map - new_size;
for (i = 0; i < new_size; i++) {
__be32 val = *(map - new_size + i);
if (i < list_size) {
val &= ~pass[i];
val |= cpu_to_be32(out_args->args[i]) & pass[i];
}
out_args->args[i] = be32_to_cpu(val);
}
out_args->args_count = list_size = new_size;
/* Iterate again with new provider */
out_args->np = new;
of_node_put(cur);
cur = new;
new = NULL;
}
put:
of_node_put(cur);
of_node_put(new);
return ret;
}
EXPORT_SYMBOL(of_parse_phandle_with_args_map);
/**
* of_count_phandle_with_args() - Find the number of phandles references in a property
* @np: pointer to a device tree node containing a list
* @list_name: property name that contains a list
* @cells_name: property name that specifies phandles' arguments count
*
* Return: The number of phandle + argument tuples within a property. It
* is a typical pattern to encode a list of phandle and variable
* arguments into a single property. The number of arguments is encoded
* by a property in the phandle-target node. For example, a gpios
* property would contain a list of GPIO specifies consisting of a
* phandle and 1 or more arguments. The number of arguments are
* determined by the #gpio-cells property in the node pointed to by the
* phandle.
*/
int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
const char *cells_name)
{
struct of_phandle_iterator it;
int rc, cur_index = 0;
/*
* If cells_name is NULL we assume a cell count of 0. This makes
* counting the phandles trivial as each 32bit word in the list is a
* phandle and no arguments are to consider. So we don't iterate through
* the list but just use the length to determine the phandle count.
*/
if (!cells_name) {
const __be32 *list;
int size;
list = of_get_property(np, list_name, &size);
if (!list)
return -ENOENT;
return size / sizeof(*list);
}
rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
if (rc)
return rc;
while ((rc = of_phandle_iterator_next(&it)) == 0)
cur_index += 1;
if (rc != -ENOENT)
return rc;
return cur_index;
}
EXPORT_SYMBOL(of_count_phandle_with_args);
static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
{
struct property **next;
for (next = list; *next; next = &(*next)->next) {
if (*next == prop) {
*next = prop->next;
prop->next = NULL;
return prop;
}
}
return NULL;
}
/**
* __of_add_property - Add a property to a node without lock operations
* @np: Caller's Device Node
* @prop: Property to add
*/
int __of_add_property(struct device_node *np, struct property *prop)
{
int rc = 0;
unsigned long flags;
struct property **next;
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_remove_property_from_list(&np->deadprops, prop);
prop->next = NULL;
next = &np->properties;
while (*next) {
if (strcmp(prop->name, (*next)->name) == 0) {
/* duplicate ! don't insert it */
rc = -EEXIST;
goto out_unlock;
}
next = &(*next)->next;
}
*next = prop;
out_unlock:
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (rc)
return rc;
__of_add_property_sysfs(np, prop);
return 0;
}
/**
* of_add_property - Add a property to a node
* @np: Caller's Device Node
* @prop: Property to add
*/
int of_add_property(struct device_node *np, struct property *prop)
{
int rc;
mutex_lock(&of_mutex);
rc = __of_add_property(np, prop);
mutex_unlock(&of_mutex);
if (!rc)
of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
return rc;
}
EXPORT_SYMBOL_GPL(of_add_property);
int __of_remove_property(struct device_node *np, struct property *prop)
{
unsigned long flags;
int rc = -ENODEV;
raw_spin_lock_irqsave(&devtree_lock, flags);
if (__of_remove_property_from_list(&np->properties, prop)) {
/* Found the property, add it to deadprops list */
prop->next = np->deadprops;
np->deadprops = prop;
rc = 0;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (rc)
return rc;
__of_remove_property_sysfs(np, prop);
return 0;
}
/**
* of_remove_property - Remove a property from a node.
* @np: Caller's Device Node
* @prop: Property to remove
*
* Note that we don't actually remove it, since we have given out
* who-knows-how-many pointers to the data using get-property.
* Instead we just move the property to the "dead properties"
* list, so it won't be found any more.
*/
int of_remove_property(struct device_node *np, struct property *prop)
{
int rc;
if (!prop)
return -ENODEV;
mutex_lock(&of_mutex);
rc = __of_remove_property(np, prop);
mutex_unlock(&of_mutex);
if (!rc)
of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
return rc;
}
EXPORT_SYMBOL_GPL(of_remove_property);
int __of_update_property(struct device_node *np, struct property *newprop,
struct property **oldpropp)
{
struct property **next, *oldprop;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_remove_property_from_list(&np->deadprops, newprop);
for (next = &np->properties; *next; next = &(*next)->next) {
if (of_prop_cmp((*next)->name, newprop->name) == 0)
break;
}
*oldpropp = oldprop = *next;
if (oldprop) {
/* replace the node */
newprop->next = oldprop->next;
*next = newprop;
oldprop->next = np->deadprops;
np->deadprops = oldprop;
} else {
/* new node */
newprop->next = NULL;
*next = newprop;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
__of_update_property_sysfs(np, newprop, oldprop);
return 0;
}
/*
* of_update_property - Update a property in a node, if the property does
* not exist, add it.
*
* Note that we don't actually remove it, since we have given out
* who-knows-how-many pointers to the data using get-property.
* Instead we just move the property to the "dead properties" list,
* and add the new property to the property list
*/
int of_update_property(struct device_node *np, struct property *newprop)
{
struct property *oldprop;
int rc;
if (!newprop->name)
return -EINVAL;
mutex_lock(&of_mutex);
rc = __of_update_property(np, newprop, &oldprop);
mutex_unlock(&of_mutex);
if (!rc)
of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
return rc;
}
static void of_alias_add(struct alias_prop *ap, struct device_node *np,
int id, const char *stem, int stem_len)
{
ap->np = np;
ap->id = id;
strscpy(ap->stem, stem, stem_len + 1);
list_add_tail(&ap->link, &aliases_lookup);
pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
ap->alias, ap->stem, ap->id, np);
}
/**
* of_alias_scan - Scan all properties of the 'aliases' node
* @dt_alloc: An allocator that provides a virtual address to memory
* for storing the resulting tree
*
* The function scans all the properties of the 'aliases' node and populates
* the global lookup table with the properties. It returns the
* number of alias properties found, or an error code in case of failure.
*/
void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
{
struct property *pp;
of_aliases = of_find_node_by_path("/aliases");
of_chosen = of_find_node_by_path("/chosen");
if (of_chosen == NULL)
of_chosen = of_find_node_by_path("/chosen@0");
if (of_chosen) {
/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
const char *name = NULL;
if (of_property_read_string(of_chosen, "stdout-path", &name))
of_property_read_string(of_chosen, "linux,stdout-path",
&name);
if (IS_ENABLED(CONFIG_PPC) && !name)
of_property_read_string(of_aliases, "stdout", &name);
if (name)
of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
if (of_stdout)
of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
}
if (!of_aliases)
return;
for_each_property_of_node(of_aliases, pp) {
const char *start = pp->name;
const char *end = start + strlen(start);
struct device_node *np;
struct alias_prop *ap;
int id, len;
/* Skip those we do not want to proceed */
if (!strcmp(pp->name, "name") ||
!strcmp(pp->name, "phandle") ||
!strcmp(pp->name, "linux,phandle"))
continue;
np = of_find_node_by_path(pp->value);
if (!np)
continue;
/* walk the alias backwards to extract the id and work out
* the 'stem' string */
while (isdigit(*(end-1)) && end > start)
end--;
len = end - start;
if (kstrtoint(end, 10, &id) < 0)
continue;
/* Allocate an alias_prop with enough space for the stem */
ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
if (!ap)
continue;
memset(ap, 0, sizeof(*ap) + len + 1);
ap->alias = start;
of_alias_add(ap, np, id, start, len);
}
}
/**
* of_alias_get_id - Get alias id for the given device_node
* @np: Pointer to the given device_node
* @stem: Alias stem of the given device_node
*
* The function travels the lookup table to get the alias id for the given
* device_node and alias stem.
*
* Return: The alias id if found.
*/
int of_alias_get_id(struct device_node *np, const char *stem)
{
struct alias_prop *app;
int id = -ENODEV;
mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (strcmp(app->stem, stem) != 0)
continue;
if (np == app->np) {
id = app->id;
break;
}
}
mutex_unlock(&of_mutex);
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_id);
/**
* of_alias_get_highest_id - Get highest alias id for the given stem
* @stem: Alias stem to be examined
*
* The function travels the lookup table to get the highest alias id for the
* given alias stem. It returns the alias id if found.
*/
int of_alias_get_highest_id(const char *stem)
{
struct alias_prop *app;
int id = -ENODEV;
mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (strcmp(app->stem, stem) != 0)
continue;
if (app->id > id)
id = app->id;
}
mutex_unlock(&of_mutex);
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
/**
* of_console_check() - Test and setup console for DT setup
* @dn: Pointer to device node
* @name: Name to use for preferred console without index. ex. "ttyS"
* @index: Index to use for preferred console.
*
* Check if the given device node matches the stdout-path property in the
* /chosen node. If it does then register it as the preferred console.
*
* Return: TRUE if console successfully setup. Otherwise return FALSE.
*/
bool of_console_check(struct device_node *dn, char *name, int index)
{
if (!dn || dn != of_stdout || console_set_on_cmdline)
return false;
/*
* XXX: cast `options' to char pointer to suppress complication
* warnings: printk, UART and console drivers expect char pointer.
*/
return !add_preferred_console(name, index, (char *)of_stdout_options);
}
EXPORT_SYMBOL_GPL(of_console_check);
/**
* of_find_next_cache_node - Find a node's subsidiary cache
* @np: node of type "cpu" or "cache"
*
* Return: A node pointer with refcount incremented, use
* of_node_put() on it when done. Caller should hold a reference
* to np.
*/
struct device_node *of_find_next_cache_node(const struct device_node *np)
{
struct device_node *child, *cache_node;
cache_node = of_parse_phandle(np, "l2-cache", 0);
if (!cache_node)
cache_node = of_parse_phandle(np, "next-level-cache", 0);
if (cache_node)
return cache_node;
/* OF on pmac has nodes instead of properties named "l2-cache"
* beneath CPU nodes.
*/
if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
for_each_child_of_node(np, child)
if (of_node_is_type(child, "cache"))
return child;
return NULL;
}
/**
* of_find_last_cache_level - Find the level at which the last cache is
* present for the given logical cpu
*
* @cpu: cpu number(logical index) for which the last cache level is needed
*
* Return: The level at which the last cache is present. It is exactly
* same as the total number of cache levels for the given logical cpu.
*/
int of_find_last_cache_level(unsigned int cpu)
{
u32 cache_level = 0;
struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
while (np) {
of_node_put(prev);
prev = np;
np = of_find_next_cache_node(np);
}
of_property_read_u32(prev, "cache-level", &cache_level);
of_node_put(prev);
return cache_level;
}
/**
* of_map_id - Translate an ID through a downstream mapping.
* @np: root complex device node.
* @id: device ID to map.
* @map_name: property name of the map to use.
* @map_mask_name: optional property name of the mask to use.
* @target: optional pointer to a target device node.
* @id_out: optional pointer to receive the translated ID.
*
* Given a device ID, look up the appropriate implementation-defined
* platform ID and/or the target device which receives transactions on that
* ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
* @id_out may be NULL if only the other is required. If @target points to
* a non-NULL device node pointer, only entries targeting that node will be
* matched; if it points to a NULL value, it will receive the device node of
* the first matching target phandle, with a reference held.
*
* Return: 0 on success or a standard error code on failure.
*/
int of_map_id(struct device_node *np, u32 id,
const char *map_name, const char *map_mask_name,
struct device_node **target, u32 *id_out)
{
u32 map_mask, masked_id;
int map_len;
const __be32 *map = NULL;
if (!np || !map_name || (!target && !id_out))
return -EINVAL;
map = of_get_property(np, map_name, &map_len);
if (!map) {
if (target)
return -ENODEV;
/* Otherwise, no map implies no translation */
*id_out = id;
return 0;
}
if (!map_len || map_len % (4 * sizeof(*map))) {
pr_err("%pOF: Error: Bad %s length: %d\n", np,
map_name, map_len);
return -EINVAL;
}
/* The default is to select all bits. */
map_mask = 0xffffffff;
/*
* Can be overridden by "{iommu,msi}-map-mask" property.
* If of_property_read_u32() fails, the default is used.
*/
if (map_mask_name)
of_property_read_u32(np, map_mask_name, &map_mask);
masked_id = map_mask & id;
for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
struct device_node *phandle_node;
u32 id_base = be32_to_cpup(map + 0);
u32 phandle = be32_to_cpup(map + 1);
u32 out_base = be32_to_cpup(map + 2);
u32 id_len = be32_to_cpup(map + 3);
if (id_base & ~map_mask) {
pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
np, map_name, map_name,
map_mask, id_base);
return -EFAULT;
}
if (masked_id < id_base || masked_id >= id_base + id_len)
continue;
phandle_node = of_find_node_by_phandle(phandle);
if (!phandle_node)
return -ENODEV;
if (target) {
if (*target)
of_node_put(phandle_node);
else
*target = phandle_node;
if (*target != phandle_node)
continue;
}
if (id_out)
*id_out = masked_id - id_base + out_base;
pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
np, map_name, map_mask, id_base, out_base,
id_len, id, masked_id - id_base + out_base);
return 0;
}
pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
id, target && *target ? *target : NULL);
/* Bypasses translation */
if (id_out)
*id_out = id;
return 0;
}
EXPORT_SYMBOL_GPL(of_map_id);
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