1 files changed, 1293 insertions, 275 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index af3b22ac762..b9864806e9b 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -18,43 +18,37 @@
  *      2 of the License, or (at your option) any later version.
  */
 #include <linux/ctype.h>
+#include <linux/cpu.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/proc_fs.h>
 
-/**
- * struct alias_prop - Alias property in 'aliases' node
- * @link:	List node to link the structure in aliases_lookup list
- * @alias:	Alias property name
- * @np:		Pointer to device_node that the alias stands for
- * @id:		Index value from end of alias name
- * @stem:	Alias string without the index
- *
- * The structure represents one alias property of 'aliases' node as
- * an entry in aliases_lookup list.
- */
-struct alias_prop {
-	struct list_head link;
-	const char *alias;
-	struct device_node *np;
-	int id;
-	char stem[0];
-};
+#include "of_private.h"
 
-static LIST_HEAD(aliases_lookup);
+LIST_HEAD(aliases_lookup);
 
-struct device_node *allnodes;
+struct device_node *of_allnodes;
+EXPORT_SYMBOL(of_allnodes);
 struct device_node *of_chosen;
 struct device_node *of_aliases;
+static struct device_node *of_stdout;
 
-static DEFINE_MUTEX(of_aliases_mutex);
+static struct kset *of_kset;
+
+/*
+ * Used to protect the of_aliases; but also overloaded to hold off addition of
+ * nodes to sysfs
+ */
+DEFINE_MUTEX(of_aliases_mutex);
 
 /* use when traversing tree through the allnext, child, sibling,
  * or parent members of struct device_node.
  */
-DEFINE_RWLOCK(devtree_lock);
+DEFINE_RAW_SPINLOCK(devtree_lock);
 
 int of_n_addr_cells(struct device_node *np)
 {
@@ -88,6 +82,13 @@ int of_n_size_cells(struct device_node *np)
 }
 EXPORT_SYMBOL(of_n_size_cells);
 
+#ifdef CONFIG_NUMA
+int __weak of_node_to_nid(struct device_node *np)
+{
+	return numa_node_id();
+}
+#endif
+
 #if defined(CONFIG_OF_DYNAMIC)
 /**
  *	of_node_get - Increment refcount of a node
@@ -99,14 +100,14 @@ EXPORT_SYMBOL(of_n_size_cells);
 struct device_node *of_node_get(struct device_node *node)
 {
 	if (node)
-		kref_get(&node->kref);
+		kobject_get(&node->kobj);
 	return node;
 }
 EXPORT_SYMBOL(of_node_get);
 
-static inline struct device_node *kref_to_device_node(struct kref *kref)
+static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
 {
-	return container_of(kref, struct device_node, kref);
+	return container_of(kobj, struct device_node, kobj);
 }
 
 /**
@@ -116,16 +117,15 @@ static inline struct device_node *kref_to_device_node(struct kref *kref)
  *	In of_node_put() this function is passed to kref_put()
  *	as the destructor.
  */
-static void of_node_release(struct kref *kref)
+static void of_node_release(struct kobject *kobj)
 {
-	struct device_node *node = kref_to_device_node(kref);
+	struct device_node *node = kobj_to_device_node(kobj);
 	struct property *prop = node->properties;
 
 	/* We should never be releasing nodes that haven't been detached. */
 	if (!of_node_check_flag(node, OF_DETACHED)) {
 		pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
 		dump_stack();
-		kref_init(&node->kref);
 		return;
 	}
 
@@ -158,21 +158,163 @@ static void of_node_release(struct kref *kref)
 void of_node_put(struct device_node *node)
 {
 	if (node)
-		kref_put(&node->kref, of_node_release);
+		kobject_put(&node->kobj);
 }
 EXPORT_SYMBOL(of_node_put);
+#else
+static void of_node_release(struct kobject *kobj)
+{
+	/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
+}
 #endif /* CONFIG_OF_DYNAMIC */
 
-struct property *of_find_property(const struct device_node *np,
-				  const char *name,
-				  int *lenp)
+struct kobj_type of_node_ktype = {
+	.release = of_node_release,
+};
+
+static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr, char *buf,
+				loff_t offset, size_t count)
+{
+	struct property *pp = container_of(bin_attr, struct property, attr);
+	return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
+}
+
+static const char *safe_name(struct kobject *kobj, const char *orig_name)
+{
+	const char *name = orig_name;
+	struct kernfs_node *kn;
+	int i = 0;
+
+	/* don't be a hero. After 16 tries give up */
+	while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
+		sysfs_put(kn);
+		if (name != orig_name)
+			kfree(name);
+		name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
+	}
+
+	if (name != orig_name)
+		pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
+			kobject_name(kobj), name);
+	return name;
+}
+
+static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+	int rc;
+
+	/* Important: Don't leak passwords */
+	bool secure = strncmp(pp->name, "security-", 9) == 0;
+
+	sysfs_bin_attr_init(&pp->attr);
+	pp->attr.attr.name = safe_name(&np->kobj, pp->name);
+	pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
+	pp->attr.size = secure ? 0 : pp->length;
+	pp->attr.read = of_node_property_read;
+
+	rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
+	WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
+	return rc;
+}
+
+static int __of_node_add(struct device_node *np)
+{
+	const char *name;
+	struct property *pp;
+	int rc;
+
+	np->kobj.kset = of_kset;
+	if (!np->parent) {
+		/* Nodes without parents are new top level trees */
+		rc = kobject_add(&np->kobj, NULL, "%s",
+				 safe_name(&of_kset->kobj, "base"));
+	} else {
+		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+		if (!name || !name[0])
+			return -EINVAL;
+
+		rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+	}
+	if (rc)
+		return rc;
+
+	for_each_property_of_node(np, pp)
+		__of_add_property_sysfs(np, pp);
+
+	return 0;
+}
+
+int of_node_add(struct device_node *np)
+{
+	int rc = 0;
+
+	BUG_ON(!of_node_is_initialized(np));
+
+	/*
+	 * Grab the mutex here so that in a race condition between of_init() and
+	 * of_node_add(), node addition will still be consistent.
+	 */
+	mutex_lock(&of_aliases_mutex);
+	if (of_kset)
+		rc = __of_node_add(np);
+	else
+		/* This scenario may be perfectly valid, but report it anyway */
+		pr_info("of_node_add(%s) before of_init()\n", np->full_name);
+	mutex_unlock(&of_aliases_mutex);
+	return rc;
+}
+
+#if defined(CONFIG_OF_DYNAMIC)
+static void of_node_remove(struct device_node *np)
+{
+	struct property *pp;
+
+	BUG_ON(!of_node_is_initialized(np));
+
+	/* only remove properties if on sysfs */
+	if (of_node_is_attached(np)) {
+		for_each_property_of_node(np, pp)
+			sysfs_remove_bin_file(&np->kobj, &pp->attr);
+		kobject_del(&np->kobj);
+	}
+
+	/* finally remove the kobj_init ref */
+	of_node_put(np);
+}
+#endif
+
+static int __init of_init(void)
+{
+	struct device_node *np;
+
+	/* Create the kset, and register existing nodes */
+	mutex_lock(&of_aliases_mutex);
+	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
+	if (!of_kset) {
+		mutex_unlock(&of_aliases_mutex);
+		return -ENOMEM;
+	}
+	for_each_of_allnodes(np)
+		__of_node_add(np);
+	mutex_unlock(&of_aliases_mutex);
+
+	/* Symlink in /proc as required by userspace ABI */
+	if (of_allnodes)
+		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
+
+	return 0;
+}
+core_initcall(of_init);
+
+static struct property *__of_find_property(const struct device_node *np,
+					   const char *name, int *lenp)
 {
 	struct property *pp;
 
 	if (!np)
 		return NULL;
 
-	read_lock(&devtree_lock);
 	for (pp = np->properties; pp; pp = pp->next) {
 		if (of_prop_cmp(pp->name, name) == 0) {
 			if (lenp)
@@ -180,7 +322,20 @@ struct property *of_find_property(const struct device_node *np,
 			break;
 		}
 	}
-	read_unlock(&devtree_lock);
+
+	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;
 }
@@ -197,14 +352,15 @@ EXPORT_SYMBOL(of_find_property);
 struct device_node *of_find_all_nodes(struct device_node *prev)
 {
 	struct device_node *np;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	np = prev ? prev->allnext : allnodes;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = prev ? prev->allnext : of_allnodes;
 	for (; np != NULL; np = np->allnext)
 		if (of_node_get(np))
 			break;
 	of_node_put(prev);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_find_all_nodes);
@@ -213,8 +369,20 @@ EXPORT_SYMBOL(of_find_all_nodes);
  * Find a property with a given name for a given node
  * and return the value.
  */
+static 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)
+			    int *lenp)
 {
 	struct property *pp = of_find_property(np, name, lenp);
 
@@ -222,27 +390,190 @@ const void *of_get_property(const struct device_node *np, const char *name,
 }
 EXPORT_SYMBOL(of_get_property);
 
+/*
+ * arch_match_cpu_phys_id - Match the given logical CPU and physical id
+ *
+ * @cpu: logical cpu index of a core/thread
+ * @phys_id: physical identifier of a core/thread
+ *
+ * CPU logical to physical index mapping is architecture specific.
+ * However this __weak function provides a default match of physical
+ * id to logical cpu index. phys_id provided here is usually values read
+ * from the device tree which must match the hardware internal registers.
+ *
+ * Returns true if the physical identifier and the logical cpu index
+ * correspond to the same core/thread, false otherwise.
+ */
+bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return (u32)phys_id == cpu;
+}
+
+/**
+ * Checks if the given "prop_name" property holds the physical id of the
+ * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
+ * NULL, local thread number within the core is returned in it.
+ */
+static bool __of_find_n_match_cpu_property(struct device_node *cpun,
+			const char *prop_name, int cpu, unsigned int *thread)
+{
+	const __be32 *cell;
+	int ac, prop_len, tid;
+	u64 hwid;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, prop_name, &prop_len);
+	if (!cell || !ac)
+		return false;
+	prop_len /= sizeof(*cell) * ac;
+	for (tid = 0; tid < prop_len; tid++) {
+		hwid = of_read_number(cell, ac);
+		if (arch_match_cpu_phys_id(cpu, hwid)) {
+			if (thread)
+				*thread = tid;
+			return true;
+		}
+		cell += ac;
+	}
+	return false;
+}
+
+/*
+ * arch_find_n_match_cpu_physical_id - See if the given device node is
+ * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
+ * else false.  If 'thread' is non-NULL, the local thread number within the
+ * core is returned in it.
+ */
+bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+					      int cpu, unsigned int *thread)
+{
+	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
+	 * for thread ids on PowerPC. If it doesn't exist fallback to
+	 * standard "reg" property.
+	 */
+	if (IS_ENABLED(CONFIG_PPC) &&
+	    __of_find_n_match_cpu_property(cpun,
+					   "ibm,ppc-interrupt-server#s",
+					   cpu, thread))
+		return true;
+
+	if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
+		return true;
+
+	return false;
+}
+
+/**
+ * of_get_cpu_node - Get device node associated with the given logical CPU
+ *
+ * @cpu: CPU number(logical index) for which device node is required
+ * @thread: if not NULL, local thread number within the physical core is
+ *          returned
+ *
+ * The main purpose of this function is to retrieve the device node for the
+ * given logical CPU index. It should be used to initialize the of_node in
+ * cpu device. Once of_node in cpu device is populated, all the further
+ * references can use that instead.
+ *
+ * CPU logical to physical index mapping is architecture specific and is built
+ * before booting secondary cores. This function uses arch_match_cpu_phys_id
+ * which can be overridden by architecture specific implementation.
+ *
+ * Returns a node pointer for the logical cpu if found, else NULL.
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+	struct device_node *cpun;
+
+	for_each_node_by_type(cpun, "cpu") {
+		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
+			return cpun;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_cpu_node);
+
+/**
+ * __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 (!device->type || of_node_cmp(type, device->type))
+			return 0;
+		score += 2;
+	}
+
+	/* Matching name is a bit better than not */
+	if (name && name[0]) {
+		if (!device->name || of_node_cmp(name, 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)
 {
-	const char* cp;
-	int cplen, l;
-
-	cp = of_get_property(device, "compatible", &cplen);
-	if (cp == NULL)
-		return 0;
-	while (cplen > 0) {
-		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
-			return 1;
-		l = strlen(cp) + 1;
-		cp += l;
-		cplen -= l;
-	}
+	unsigned long flags;
+	int res;
 
-	return 0;
+	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);
 
@@ -268,19 +599,22 @@ int of_machine_is_compatible(const char *compat)
 EXPORT_SYMBOL(of_machine_is_compatible);
 
 /**
- *  of_device_is_available - check if a device is available for use
+ *  __of_device_is_available - check if a device is available for use
  *
- *  @device: Node to check for availability
+ *  @device: Node to check for availability, with locks already held
  *
  *  Returns 1 if the status property is absent or set to "okay" or "ok",
  *  0 otherwise
  */
-int of_device_is_available(const struct device_node *device)
+static int __of_device_is_available(const struct device_node *device)
 {
 	const char *status;
 	int statlen;
 
-	status = of_get_property(device, "status", &statlen);
+	if (!device)
+		return 0;
+
+	status = __of_get_property(device, "status", &statlen);
 	if (status == NULL)
 		return 1;
 
@@ -291,6 +625,26 @@ int of_device_is_available(const struct device_node *device)
 
 	return 0;
 }
+
+/**
+ *  of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability
+ *
+ *  Returns 1 if the status property is absent or set to "okay" or "ok",
+ *  0 otherwise
+ */
+int of_device_is_available(const struct device_node *device)
+{
+	unsigned long flags;
+	int 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);
 
 /**
@@ -303,13 +657,14 @@ EXPORT_SYMBOL(of_device_is_available);
 struct device_node *of_get_parent(const struct device_node *node)
 {
 	struct device_node *np;
+	unsigned long flags;
 
 	if (!node)
 		return NULL;
 
-	read_lock(&devtree_lock);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	np = of_node_get(node->parent);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_get_parent);
@@ -328,16 +683,37 @@ EXPORT_SYMBOL(of_get_parent);
 struct device_node *of_get_next_parent(struct device_node *node)
 {
 	struct device_node *parent;
+	unsigned long flags;
 
 	if (!node)
 		return NULL;
 
-	read_lock(&devtree_lock);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	parent = of_node_get(node->parent);
 	of_node_put(node);
-	read_unlock(&devtree_lock);
+	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;
+	for (; next; next = next->sibling)
+		if (of_node_get(next))
+			break;
+	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
@@ -351,14 +727,11 @@ struct device_node *of_get_next_child(const struct device_node *node,
 	struct device_node *prev)
 {
 	struct device_node *next;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	next = prev ? prev->sibling : node->child;
-	for (; next; next = next->sibling)
-		if (of_node_get(next))
-			break;
-	of_node_put(prev);
-	read_unlock(&devtree_lock);
+	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);
@@ -375,17 +748,21 @@ struct device_node *of_get_next_available_child(const struct device_node *node,
 	struct device_node *prev)
 {
 	struct device_node *next;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
 
-	read_lock(&devtree_lock);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	next = prev ? prev->sibling : node->child;
 	for (; next; next = next->sibling) {
-		if (!of_device_is_available(next))
+		if (!__of_device_is_available(next))
 			continue;
 		if (of_node_get(next))
 			break;
 	}
 	of_node_put(prev);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return next;
 }
 EXPORT_SYMBOL(of_get_next_available_child);
@@ -413,24 +790,80 @@ struct device_node *of_get_child_by_name(const struct device_node *node,
 }
 EXPORT_SYMBOL(of_get_child_by_name);
 
+static struct device_node *__of_find_node_by_path(struct device_node *parent,
+						const char *path)
+{
+	struct device_node *child;
+	int len = strchrnul(path, '/') - path;
+
+	if (!len)
+		return NULL;
+
+	__for_each_child_of_node(parent, child) {
+		const char *name = strrchr(child->full_name, '/');
+		if (WARN(!name, "malformed device_node %s\n", child->full_name))
+			continue;
+		name++;
+		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
+			return child;
+	}
+	return NULL;
+}
+
 /**
  *	of_find_node_by_path - Find a node matching a full OF path
- *	@path:	The full path to match
+ *	@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.
+ *
+ *	Valid paths:
+ *		/foo/bar	Full path
+ *		foo		Valid alias
+ *		foo/bar		Valid alias + relative path
  *
  *	Returns a node pointer with refcount incremented, use
  *	of_node_put() on it when done.
  */
 struct device_node *of_find_node_by_path(const char *path)
 {
-	struct device_node *np = allnodes;
+	struct device_node *np = NULL;
+	struct property *pp;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	for (; np; np = np->allnext) {
-		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
-		    && of_node_get(np))
-			break;
+	if (strcmp(path, "/") == 0)
+		return of_node_get(of_allnodes);
+
+	/* The path could begin with an alias */
+	if (*path != '/') {
+		char *p = strchrnul(path, '/');
+		int 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_allnodes);
+	while (np && *path == '/') {
+		path++; /* Increment past '/' delimiter */
+		np = __of_find_node_by_path(np, path);
+		path = strchrnul(path, '/');
 	}
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_find_node_by_path);
@@ -450,15 +883,16 @@ struct device_node *of_find_node_by_name(struct device_node *from,
 	const char *name)
 {
 	struct device_node *np;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	np = from ? from->allnext : allnodes;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : of_allnodes;
 	for (; np; np = np->allnext)
 		if (np->name && (of_node_cmp(np->name, name) == 0)
 		    && of_node_get(np))
 			break;
 	of_node_put(from);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_find_node_by_name);
@@ -479,15 +913,16 @@ struct device_node *of_find_node_by_type(struct device_node *from,
 	const char *type)
 {
 	struct device_node *np;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	np = from ? from->allnext : allnodes;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : of_allnodes;
 	for (; np; np = np->allnext)
 		if (np->type && (of_node_cmp(np->type, type) == 0)
 		    && of_node_get(np))
 			break;
 	of_node_put(from);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_find_node_by_type);
@@ -510,18 +945,17 @@ struct device_node *of_find_compatible_node(struct device_node *from,
 	const char *type, const char *compatible)
 {
 	struct device_node *np;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	np = from ? from->allnext : allnodes;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : of_allnodes;
 	for (; np; np = np->allnext) {
-		if (type
-		    && !(np->type && (of_node_cmp(np->type, type) == 0)))
-			continue;
-		if (of_device_is_compatible(np, compatible) && of_node_get(np))
+		if (__of_device_is_compatible(np, compatible, type, NULL) &&
+		    of_node_get(np))
 			break;
 	}
 	of_node_put(from);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_find_compatible_node);
@@ -543,9 +977,10 @@ struct device_node *of_find_node_with_property(struct device_node *from,
 {
 	struct device_node *np;
 	struct property *pp;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	np = from ? from->allnext : allnodes;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : of_allnodes;
 	for (; np; np = np->allnext) {
 		for (pp = np->properties; pp; pp = pp->next) {
 			if (of_prop_cmp(pp->name, prop_name) == 0) {
@@ -556,11 +991,33 @@ struct device_node *of_find_node_with_property(struct device_node *from,
 	}
 out:
 	of_node_put(from);
-	read_unlock(&devtree_lock);
+	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 an device_node has a matching of_match structure
  *	@matches:	array of of device match structures to search in
@@ -571,56 +1028,55 @@ EXPORT_SYMBOL(of_find_node_with_property);
 const struct of_device_id *of_match_node(const struct of_device_id *matches,
 					 const struct device_node *node)
 {
-	if (!matches)
-		return NULL;
+	const struct of_device_id *match;
+	unsigned long flags;
 
-	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
-		int match = 1;
-		if (matches->name[0])
-			match &= node->name
-				&& !strcmp(matches->name, node->name);
-		if (matches->type[0])
-			match &= node->type
-				&& !strcmp(matches->type, node->type);
-		if (matches->compatible[0])
-			match &= of_device_is_compatible(node,
-						matches->compatible);
-		if (match)
-			return matches;
-		matches++;
-	}
-	return NULL;
+	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 - Find a node based on an of_device_id match
- *				table.
+ *	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
  *
  *	Returns a node pointer with refcount incremented, use
  *	of_node_put() on it when done.
  */
-struct device_node *of_find_matching_node(struct device_node *from,
-					  const struct of_device_id *matches)
+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;
 
-	read_lock(&devtree_lock);
-	np = from ? from->allnext : allnodes;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : of_allnodes;
 	for (; np; np = np->allnext) {
-		if (of_match_node(matches, np) && of_node_get(np))
+		m = __of_match_node(matches, np);
+		if (m && of_node_get(np)) {
+			if (match)
+				*match = m;
 			break;
+		}
 	}
 	of_node_put(from);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
-EXPORT_SYMBOL(of_find_matching_node);
+EXPORT_SYMBOL(of_find_matching_node_and_match);
 
 /**
  * of_modalias_node - Lookup appropriate modalias for a device node
@@ -659,47 +1115,200 @@ EXPORT_SYMBOL_GPL(of_modalias_node);
 struct device_node *of_find_node_by_phandle(phandle handle)
 {
 	struct device_node *np;
+	unsigned long flags;
 
-	read_lock(&devtree_lock);
-	for (np = allnodes; np; np = np->allnext)
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for (np = of_allnodes; np; np = np->allnext)
 		if (np->phandle == handle)
 			break;
 	of_node_get(np);
-	read_unlock(&devtree_lock);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
 EXPORT_SYMBOL(of_find_node_by_phandle);
 
 /**
+ * of_property_count_elems_of_size - Count the number of elements in a property
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @elem_size:	size of the individual element
+ *
+ * Search for a property in a device node and count the number of elements of
+ * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
+ * property does not exist or its length does not match a multiple of elem_size
+ * and -ENODATA if the property does not have a value.
+ */
+int of_property_count_elems_of_size(const struct device_node *np,
+				const char *propname, int elem_size)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	if (prop->length % elem_size != 0) {
+		pr_err("size of %s in node %s is not a multiple of %d\n",
+		       propname, np->full_name, elem_size);
+		return -EINVAL;
+	}
+
+	return prop->length / elem_size;
+}
+EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
+
+/**
+ * of_find_property_value_of_size
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @len:	requested length of property value
+ *
+ * Search for a property in a device node and valid the requested size.
+ * Returns the property value on success, -EINVAL if the property does not
+ *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ */
+static void *of_find_property_value_of_size(const struct device_node *np,
+			const char *propname, u32 len)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return ERR_PTR(-EINVAL);
+	if (!prop->value)
+		return ERR_PTR(-ENODATA);
+	if (len > prop->length)
+		return ERR_PTR(-EOVERFLOW);
+
+	return prop->value;
+}
+
+/**
+ * of_property_read_u32_index - Find and read a u32 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u32 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 32-bit value from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_u32_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u32 *out_value)
+{
+	const u32 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be32_to_cpup(((__be32 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u32_index);
+
+/**
+ * of_property_read_u8_array - Find and read an array of u8 from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 8-bit value(s) from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * dts entry of array should be like:
+ *	property = /bits/ 8 <0x50 0x60 0x70>;
+ *
+ * The out_values is modified only if a valid u8 value can be decoded.
+ */
+int of_property_read_u8_array(const struct device_node *np,
+			const char *propname, u8 *out_values, size_t sz)
+{
+	const u8 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--)
+		*out_values++ = *val++;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u8_array);
+
+/**
+ * of_property_read_u16_array - Find and read an array of u16 from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
+ *
+ * Search for a property in a device node and read 16-bit value(s) from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * dts entry of array should be like:
+ *	property = /bits/ 16 <0x5000 0x6000 0x7000>;
+ *
+ * The out_values is modified only if a valid u16 value can be decoded.
+ */
+int of_property_read_u16_array(const struct device_node *np,
+			const char *propname, u16 *out_values, size_t sz)
+{
+	const __be16 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	while (sz--)
+		*out_values++ = be16_to_cpup(val++);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u16_array);
+
+/**
  * of_property_read_u32_array - Find and read an array of 32 bit integers
  * from a property.
  *
  * @np:		device node from which the property value is to be read.
  * @propname:	name of the property to be searched.
- * @out_value:	pointer to return value, modified only if return value is 0.
+ * @out_values:	pointer to return value, modified only if return value is 0.
+ * @sz:		number of array elements to read
  *
  * Search for a property in a device node and read 32-bit value(s) from
  * it. Returns 0 on success, -EINVAL if the property does not exist,
  * -ENODATA if property does not have a value, and -EOVERFLOW if the
  * property data isn't large enough.
  *
- * The out_value is modified only if a valid u32 value can be decoded.
+ * The out_values is modified only if a valid u32 value can be decoded.
  */
 int of_property_read_u32_array(const struct device_node *np,
 			       const char *propname, u32 *out_values,
 			       size_t sz)
 {
-	struct property *prop = of_find_property(np, propname, NULL);
-	const __be32 *val;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz * sizeof(*out_values)));
 
-	if (!prop)
-		return -EINVAL;
-	if (!prop->value)
-		return -ENODATA;
-	if ((sz * sizeof(*out_values)) > prop->length)
-		return -EOVERFLOW;
+	if (IS_ERR(val))
+		return PTR_ERR(val);
 
-	val = prop->value;
 	while (sz--)
 		*out_values++ = be32_to_cpup(val++);
 	return 0;
@@ -722,15 +1331,13 @@ EXPORT_SYMBOL_GPL(of_property_read_u32_array);
 int of_property_read_u64(const struct device_node *np, const char *propname,
 			 u64 *out_value)
 {
-	struct property *prop = of_find_property(np, propname, NULL);
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						sizeof(*out_value));
 
-	if (!prop)
-		return -EINVAL;
-	if (!prop->value)
-		return -ENODATA;
-	if (sizeof(*out_value) > prop->length)
-		return -EOVERFLOW;
-	*out_value = of_read_number(prop->value, 2);
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = of_read_number(val, 2);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_property_read_u64);
@@ -883,68 +1490,23 @@ int of_property_count_strings(struct device_node *np, const char *propname)
 }
 EXPORT_SYMBOL_GPL(of_property_count_strings);
 
-/**
- * of_parse_phandle - Resolve a phandle property to a device_node pointer
- * @np: Pointer to device node holding phandle property
- * @phandle_name: Name of property holding a phandle value
- * @index: For properties holding a table of phandles, this is the index into
- *         the table
- *
- * Returns the device_node pointer with refcount incremented.  Use
- * of_node_put() on it when done.
- */
-struct device_node *
-of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
+void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
 {
-	const __be32 *phandle;
-	int size;
-
-	phandle = of_get_property(np, phandle_name, &size);
-	if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
-		return NULL;
-
-	return of_find_node_by_phandle(be32_to_cpup(phandle + index));
+	int i;
+	printk("%s %s", msg, of_node_full_name(args->np));
+	for (i = 0; i < args->args_count; i++)
+		printk(i ? ",%08x" : ":%08x", args->args[i]);
+	printk("\n");
 }
-EXPORT_SYMBOL(of_parse_phandle);
 
-/**
- * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
- * @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
- * @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.
- *
- * Caller is responsible to call of_node_put() on the returned out_args->node
- * pointer.
- *
- * Example:
- *
- * phandle1: node1 {
- * 	#list-cells = <2>;
- * }
- *
- * phandle2: node2 {
- * 	#list-cells = <1>;
- * }
- *
- * node3 {
- * 	list = <&phandle1 1 2 &phandle2 3>;
- * }
- *
- * To get a device_node of the `node2' node you may call this:
- * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
- */
-int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
-				const char *cells_name, int index,
-				struct of_phandle_args *out_args)
+static 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)
 {
 	const __be32 *list, *list_end;
-	int size, cur_index = 0;
+	int rc = 0, size, cur_index = 0;
 	uint32_t count = 0;
 	struct device_node *node = NULL;
 	phandle phandle;
@@ -957,6 +1519,7 @@ int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
 
 	/* Loop over the phandles until all the requested entry is found */
 	while (list < list_end) {
+		rc = -EINVAL;
 		count = 0;
 
 		/*
@@ -967,19 +1530,32 @@ int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
 		if (phandle) {
 			/*
 			 * Find the provider node and parse the #*-cells
-			 * property to determine the argument length
+			 * property to determine the argument length.
+			 *
+			 * This is not needed if the cell count is hard-coded
+			 * (i.e. cells_name not set, but cell_count is set),
+			 * except when we're going to return the found node
+			 * below.
 			 */
-			node = of_find_node_by_phandle(phandle);
-			if (!node) {
-				pr_err("%s: could not find phandle\n",
-					 np->full_name);
-				break;
+			if (cells_name || cur_index == index) {
+				node = of_find_node_by_phandle(phandle);
+				if (!node) {
+					pr_err("%s: could not find phandle\n",
+						np->full_name);
+					goto err;
+				}
 			}
-			if (of_property_read_u32(node, cells_name, &count)) {
-				pr_err("%s: could not get %s for %s\n",
-					 np->full_name, cells_name,
-					 node->full_name);
-				break;
+
+			if (cells_name) {
+				if (of_property_read_u32(node, cells_name,
+							 &count)) {
+					pr_err("%s: could not get %s for %s\n",
+						np->full_name, cells_name,
+						node->full_name);
+					goto err;
+				}
+			} else {
+				count = cell_count;
 			}
 
 			/*
@@ -989,7 +1565,7 @@ int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
 			if (list + count > list_end) {
 				pr_err("%s: arguments longer than property\n",
 					 np->full_name);
-				break;
+				goto err;
 			}
 		}
 
@@ -999,9 +1575,10 @@ int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
 		 * index matches, then fill the out_args structure and return,
 		 * or return -ENOENT for an empty entry.
 		 */
+		rc = -ENOENT;
 		if (cur_index == index) {
 			if (!phandle)
-				return -ENOENT;
+				goto err;
 
 			if (out_args) {
 				int i;
@@ -1011,7 +1588,11 @@ int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
 				out_args->args_count = count;
 				for (i = 0; i < count; i++)
 					out_args->args[i] = be32_to_cpup(list++);
+			} else {
+				of_node_put(node);
 			}
+
+			/* Found it! return success */
 			return 0;
 		}
 
@@ -1021,59 +1602,239 @@ int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
 		cur_index++;
 	}
 
-	/* Loop exited without finding a valid entry; return an error */
+	/*
+	 * Unlock node before returning result; will be one of:
+	 * -ENOENT : index is for empty phandle
+	 * -EINVAL : parsing error on data
+	 * [1..n]  : Number of phandle (count mode; when index = -1)
+	 */
+	rc = index < 0 ? cur_index : -ENOENT;
+ err:
 	if (node)
 		of_node_put(node);
-	return -EINVAL;
+	return rc;
+}
+
+/**
+ * of_parse_phandle - Resolve a phandle property to a device_node pointer
+ * @np: Pointer to device node holding phandle property
+ * @phandle_name: Name of property holding a phandle value
+ * @index: For properties holding a table of phandles, this is the index into
+ *         the table
+ *
+ * Returns the device_node pointer with refcount incremented.  Use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_parse_phandle(const struct device_node *np,
+				     const char *phandle_name, int index)
+{
+	struct of_phandle_args args;
+
+	if (index < 0)
+		return NULL;
+
+	if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
+					 index, &args))
+		return NULL;
+
+	return args.np;
+}
+EXPORT_SYMBOL(of_parse_phandle);
+
+/**
+ * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
+ * @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
+ * @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.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->node
+ * pointer.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * 	#list-cells = <2>;
+ * }
+ *
+ * phandle2: node2 {
+ * 	#list-cells = <1>;
+ * }
+ *
+ * node3 {
+ * 	list = <&phandle1 1 2 &phandle2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
+ */
+int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
+				const char *cells_name, int index,
+				struct of_phandle_args *out_args)
+{
+	if (index < 0)
+		return -EINVAL;
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+					    index, out_args);
 }
 EXPORT_SYMBOL(of_parse_phandle_with_args);
 
 /**
- * prom_add_property - Add a property to a node
+ * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cell_count: number of argument cells following the phandle
+ * @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.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->node
+ * pointer.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * }
+ *
+ * phandle2: node2 {
+ * }
+ *
+ * node3 {
+ * 	list = <&phandle1 0 2 &phandle2 2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
+ */
+int of_parse_phandle_with_fixed_args(const struct device_node *np,
+				const char *list_name, int cell_count,
+				int index, struct of_phandle_args *out_args)
+{
+	if (index < 0)
+		return -EINVAL;
+	return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
+					   index, out_args);
+}
+EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
+
+/**
+ * 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
+ *
+ * Returns 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)
+{
+	return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
+					    NULL);
+}
+EXPORT_SYMBOL(of_count_phandle_with_args);
+
+#if defined(CONFIG_OF_DYNAMIC)
+static int of_property_notify(int action, struct device_node *np,
+			      struct property *prop)
+{
+	struct of_prop_reconfig pr;
+
+	/* only call notifiers if the node is attached */
+	if (!of_node_is_attached(np))
+		return 0;
+
+	pr.dn = np;
+	pr.prop = prop;
+	return of_reconfig_notify(action, &pr);
+}
+#else
+static int of_property_notify(int action, struct device_node *np,
+			      struct property *prop)
+{
+	return 0;
+}
+#endif
+
+/**
+ * __of_add_property - Add a property to a node without lock operations
  */
-int prom_add_property(struct device_node *np, struct property *prop)
+static int __of_add_property(struct device_node *np, struct property *prop)
 {
 	struct property **next;
-	unsigned long flags;
 
 	prop->next = NULL;
-	write_lock_irqsave(&devtree_lock, flags);
 	next = &np->properties;
 	while (*next) {
-		if (strcmp(prop->name, (*next)->name) == 0) {
+		if (strcmp(prop->name, (*next)->name) == 0)
 			/* duplicate ! don't insert it */
-			write_unlock_irqrestore(&devtree_lock, flags);
-			return -1;
-		}
+			return -EEXIST;
+
 		next = &(*next)->next;
 	}
 	*next = prop;
-	write_unlock_irqrestore(&devtree_lock, flags);
-
-#ifdef CONFIG_PROC_DEVICETREE
-	/* try to add to proc as well if it was initialized */
-	if (np->pde)
-		proc_device_tree_add_prop(np->pde, prop);
-#endif /* CONFIG_PROC_DEVICETREE */
 
 	return 0;
 }
 
 /**
- * prom_remove_property - Remove a property from a node.
+ * of_add_property - Add a property to a node
+ */
+int of_add_property(struct device_node *np, struct property *prop)
+{
+	unsigned long flags;
+	int rc;
+
+	rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
+	if (rc)
+		return rc;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_add_property(np, prop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	if (rc)
+		return rc;
+
+	if (of_node_is_attached(np))
+		__of_add_property_sysfs(np, prop);
+
+	return rc;
+}
+
+/**
+ * of_remove_property - Remove a property from a node.
  *
  * 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 prom_remove_property(struct device_node *np, struct property *prop)
+int of_remove_property(struct device_node *np, struct property *prop)
 {
 	struct property **next;
 	unsigned long flags;
 	int found = 0;
+	int rc;
 
-	write_lock_irqsave(&devtree_lock, flags);
+	rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
+	if (rc)
+		return rc;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	next = &np->properties;
 	while (*next) {
 		if (*next == prop) {
@@ -1086,22 +1847,22 @@ int prom_remove_property(struct device_node *np, struct property *prop)
 		}
 		next = &(*next)->next;
 	}
-	write_unlock_irqrestore(&devtree_lock, flags);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
 	if (!found)
 		return -ENODEV;
 
-#ifdef CONFIG_PROC_DEVICETREE
-	/* try to remove the proc node as well */
-	if (np->pde)
-		proc_device_tree_remove_prop(np->pde, prop);
-#endif /* CONFIG_PROC_DEVICETREE */
+	/* at early boot, bail hear and defer setup to of_init() */
+	if (!of_kset)
+		return 0;
+
+	sysfs_remove_bin_file(&np->kobj, &prop->attr);
 
 	return 0;
 }
 
 /*
- * prom_update_property - Update a property in a node, if the property does
+ * 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
@@ -1109,44 +1870,48 @@ int prom_remove_property(struct device_node *np, struct property *prop)
  * Instead we just move the property to the "dead properties" list,
  * and add the new property to the property list
  */
-int prom_update_property(struct device_node *np,
-			 struct property *newprop)
+int of_update_property(struct device_node *np, struct property *newprop)
 {
 	struct property **next, *oldprop;
 	unsigned long flags;
-	int found = 0;
+	int rc;
+
+	rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
+	if (rc)
+		return rc;
 
 	if (!newprop->name)
 		return -EINVAL;
 
-	oldprop = of_find_property(np, newprop->name, NULL);
-	if (!oldprop)
-		return prom_add_property(np, newprop);
-
-	write_lock_irqsave(&devtree_lock, flags);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	next = &np->properties;
-	while (*next) {
+	oldprop = __of_find_property(np, newprop->name, NULL);
+	if (!oldprop) {
+		/* add the new node */
+		rc = __of_add_property(np, newprop);
+	} else while (*next) {
+		/* replace the node */
 		if (*next == oldprop) {
-			/* found the node */
 			newprop->next = oldprop->next;
 			*next = newprop;
 			oldprop->next = np->deadprops;
 			np->deadprops = oldprop;
-			found = 1;
 			break;
 		}
 		next = &(*next)->next;
 	}
-	write_unlock_irqrestore(&devtree_lock, flags);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	if (rc)
+		return rc;
 
-	if (!found)
-		return -ENODEV;
+	/* At early boot, bail out and defer setup to of_init() */
+	if (!of_kset)
+		return 0;
 
-#ifdef CONFIG_PROC_DEVICETREE
-	/* try to add to proc as well if it was initialized */
-	if (np->pde)
-		proc_device_tree_update_prop(np->pde, newprop, oldprop);
-#endif /* CONFIG_PROC_DEVICETREE */
+	/* Update the sysfs attribute */
+	if (oldprop)
+		sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+	__of_add_property_sysfs(np, newprop);
 
 	return 0;
 }
@@ -1160,19 +1925,50 @@ int prom_update_property(struct device_node *np,
  * device tree nodes.
  */
 
+static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
+
+int of_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
+
+int of_reconfig_notify(unsigned long action, void *p)
+{
+	int rc;
+
+	rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
+	return notifier_to_errno(rc);
+}
+
 /**
  * of_attach_node - Plug a device node into the tree and global list.
  */
-void of_attach_node(struct device_node *np)
+int of_attach_node(struct device_node *np)
 {
 	unsigned long flags;
+	int rc;
+
+	rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
+	if (rc)
+		return rc;
 
-	write_lock_irqsave(&devtree_lock, flags);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
 	np->sibling = np->parent->child;
-	np->allnext = allnodes;
+	np->allnext = np->parent->allnext;
+	np->parent->allnext = np;
 	np->parent->child = np;
-	allnodes = np;
-	write_unlock_irqrestore(&devtree_lock, flags);
+	of_node_clear_flag(np, OF_DETACHED);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	of_node_add(np);
+	return 0;
 }
 
 /**
@@ -1181,22 +1977,35 @@ void of_attach_node(struct device_node *np)
  * The caller must hold a reference to the node.  The memory associated with
  * the node is not freed until its refcount goes to zero.
  */
-void of_detach_node(struct device_node *np)
+int of_detach_node(struct device_node *np)
 {
 	struct device_node *parent;
 	unsigned long flags;
+	int rc = 0;
 
-	write_lock_irqsave(&devtree_lock, flags);
+	rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
+	if (rc)
+		return rc;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (of_node_check_flag(np, OF_DETACHED)) {
+		/* someone already detached it */
+		raw_spin_unlock_irqrestore(&devtree_lock, flags);
+		return rc;
+	}
 
 	parent = np->parent;
-	if (!parent)
-		goto out_unlock;
+	if (!parent) {
+		raw_spin_unlock_irqrestore(&devtree_lock, flags);
+		return rc;
+	}
 
-	if (allnodes == np)
-		allnodes = np->allnext;
+	if (of_allnodes == np)
+		of_allnodes = np->allnext;
 	else {
 		struct device_node *prev;
-		for (prev = allnodes;
+		for (prev = of_allnodes;
 		     prev->allnext != np;
 		     prev = prev->allnext)
 			;
@@ -1215,9 +2024,10 @@ void of_detach_node(struct device_node *np)
 	}
 
 	of_node_set_flag(np, OF_DETACHED);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-out_unlock:
-	write_unlock_irqrestore(&devtree_lock, flags);
+	of_node_remove(np);
+	return rc;
 }
 #endif /* defined(CONFIG_OF_DYNAMIC) */
 
@@ -1250,6 +2060,15 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
 	of_chosen = of_find_node_by_path("/chosen");
 	if (of_chosen == NULL)
 		of_chosen = of_find_node_by_path("/chosen@0");
+
+	if (of_chosen) {
+		const char *name = of_get_property(of_chosen, "stdout-path", NULL);
+		if (!name)
+			name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+		if (name)
+			of_stdout = of_find_node_by_path(name);
+	}
+
 	of_aliases = of_find_node_by_path("/aliases");
 	if (!of_aliases)
 		return;
@@ -1284,6 +2103,7 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
 		ap = dt_alloc(sizeof(*ap) + len + 1, 4);
 		if (!ap)
 			continue;
+		memset(ap, 0, sizeof(*ap) + len + 1);
 		ap->alias = start;
 		of_alias_add(ap, np, id, start, len);
 	}
@@ -1294,8 +2114,8 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
  * @np:		Pointer to the given device_node
  * @stem:	Alias stem of the given device_node
  *
- * The function travels the lookup table to get alias id for the given
- * device_node and alias stem.  It returns the alias id if find it.
+ * The function travels the lookup table to get the alias id for the given
+ * device_node and alias stem.  It returns the alias id if found.
  */
 int of_alias_get_id(struct device_node *np, const char *stem)
 {
@@ -1358,3 +2178,201 @@ const char *of_prop_next_string(struct property *prop, const char *cur)
 	return curv;
 }
 EXPORT_SYMBOL_GPL(of_prop_next_string);
+
+/**
+ * of_device_is_stdout_path - check if a device node matches the
+ *                            linux,stdout-path property
+ *
+ * Check if this device node matches the linux,stdout-path property
+ * in the chosen node. return true if yes, false otherwise.
+ */
+int of_device_is_stdout_path(struct device_node *dn)
+{
+	if (!of_stdout)
+		return false;
+
+	return of_stdout == dn;
+}
+EXPORT_SYMBOL_GPL(of_device_is_stdout_path);
+
+/**
+ *	of_find_next_cache_node - Find a node's subsidiary cache
+ *	@np:	node of type "cpu" or "cache"
+ *
+ *	Returns 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;
+	const phandle *handle;
+
+	handle = of_get_property(np, "l2-cache", NULL);
+	if (!handle)
+		handle = of_get_property(np, "next-level-cache", NULL);
+
+	if (handle)
+		return of_find_node_by_phandle(be32_to_cpup(handle));
+
+	/* OF on pmac has nodes instead of properties named "l2-cache"
+	 * beneath CPU nodes.
+	 */
+	if (!strcmp(np->type, "cpu"))
+		for_each_child_of_node(np, child)
+			if (!strcmp(child->type, "cache"))
+				return child;
+
+	return NULL;
+}
+
+/**
+ * of_graph_parse_endpoint() - parse common endpoint node properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to the OF endpoint data structure
+ *
+ * The caller should hold a reference to @node.
+ */
+int of_graph_parse_endpoint(const struct device_node *node,
+			    struct of_endpoint *endpoint)
+{
+	struct device_node *port_node = of_get_parent(node);
+
+	WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
+		  __func__, node->full_name);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_node = node;
+	/*
+	 * It doesn't matter whether the two calls below succeed.
+	 * If they don't then the default value 0 is used.
+	 */
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	of_node_put(port_node);
+
+	return 0;
+}
+EXPORT_SYMBOL(of_graph_parse_endpoint);
+
+/**
+ * of_graph_get_next_endpoint() - get next endpoint node
+ * @parent: pointer to the parent device node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is not decremented, the caller have to use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+					struct device_node *prev)
+{
+	struct device_node *endpoint;
+	struct device_node *port;
+
+	if (!parent)
+		return NULL;
+
+	/*
+	 * Start by locating the port node. If no previous endpoint is specified
+	 * search for the first port node, otherwise get the previous endpoint
+	 * parent port node.
+	 */
+	if (!prev) {
+		struct device_node *node;
+
+		node = of_get_child_by_name(parent, "ports");
+		if (node)
+			parent = node;
+
+		port = of_get_child_by_name(parent, "port");
+		of_node_put(node);
+
+		if (!port) {
+			pr_err("%s(): no port node found in %s\n",
+			       __func__, parent->full_name);
+			return NULL;
+		}
+	} else {
+		port = of_get_parent(prev);
+		if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
+			      __func__, prev->full_name))
+			return NULL;
+
+		/*
+		 * Avoid dropping prev node refcount to 0 when getting the next
+		 * child below.
+		 */
+		of_node_get(prev);
+	}
+
+	while (1) {
+		/*
+		 * Now that we have a port node, get the next endpoint by
+		 * getting the next child. If the previous endpoint is NULL this
+		 * will return the first child.
+		 */
+		endpoint = of_get_next_child(port, prev);
+		if (endpoint) {
+			of_node_put(port);
+			return endpoint;
+		}
+
+		/* No more endpoints under this port, try the next one. */
+		prev = NULL;
+
+		do {
+			port = of_get_next_child(parent, port);
+			if (!port)
+				return NULL;
+		} while (of_node_cmp(port->name, "port"));
+	}
+}
+EXPORT_SYMBOL(of_graph_get_next_endpoint);
+
+/**
+ * of_graph_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port_parent(
+			       const struct device_node *node)
+{
+	struct device_node *np;
+	unsigned int depth;
+
+	/* Get remote endpoint node. */
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+
+	/* Walk 3 levels up only if there is 'ports' node. */
+	for (depth = 3; depth && np; depth--) {
+		np = of_get_next_parent(np);
+		if (depth == 2 && of_node_cmp(np->name, "ports"))
+			break;
+	}
+	return np;
+}
+EXPORT_SYMBOL(of_graph_get_remote_port_parent);
+
+/**
+ * of_graph_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port(const struct device_node *node)
+{
+	struct device_node *np;
+
+	/* Get remote endpoint node. */
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+	if (!np)
+		return NULL;
+	return of_get_next_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port);