From e7a00e4210e4cc980e3ba67ec7301af54061d14b Mon Sep 17 00:00:00 2001
From: Sebastian Reichel
Date: Sun, 6 Apr 2014 12:52:11 +0200
Subject: of: introduce of_property_read_s32

Introduce signed 32bit integer of_property_read method.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 include/linux/of.h | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'include/linux/of.h')

diff --git a/include/linux/of.h b/include/linux/of.h
index 29f0adc5f3e4..30912939a610 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -760,6 +760,13 @@ static inline int of_property_read_u32(const struct device_node *np,
 	return of_property_read_u32_array(np, propname, out_value, 1);
 }
 
+static inline int of_property_read_s32(const struct device_node *np,
+				       const char *propname,
+				       s32 *out_value)
+{
+	return of_property_read_u32(np, propname, (u32*) out_value);
+}
+
 #define of_property_for_each_u32(np, propname, prop, p, u)	\
 	for (prop = of_find_property(np, propname, NULL),	\
 		p = of_prop_next_u32(prop, NULL, &u);		\
-- 
cgit v1.2.3-55-g7522


From 5063e25a302e6a83f6590d9a06bd5f6400b17430 Mon Sep 17 00:00:00 2001
From: Grant Likely
Date: Fri, 3 Oct 2014 16:28:27 +0100
Subject: of: Eliminate of_allnodes list

The device tree structure is composed of two lists; the 'allnodes' list
which is a singly linked list containing every node in the tree, and the
child->parent structure where each parent node has a singly linked list
of children. All of the data in the allnodes list can be easily
reproduced with the parent-child lists, so of_allnodes is actually
unnecessary. Remove it entirely which saves a bit of memory and
simplifies the data structure quite a lot.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Gaurav Minocha <gaurav.minocha.os@gmail.com>
Cc: Pantelis Antoniou <pantelis@pantelis.antoniou@konsulko.com>
---
 Documentation/devicetree/of_selftest.txt | 20 ++-------
 Documentation/devicetree/todo.txt        |  1 -
 drivers/mfd/vexpress-sysreg.c            |  2 +-
 drivers/of/base.c                        | 53 ++++++++++++++----------
 drivers/of/dynamic.c                     | 13 ------
 drivers/of/fdt.c                         | 30 +++++++-------
 drivers/of/pdt.c                         | 27 ++++--------
 drivers/of/selftest.c                    | 71 +++++++++++++++-----------------
 include/linux/of.h                       | 11 ++---
 include/linux/of_pdt.h                   |  3 +-
 10 files changed, 98 insertions(+), 133 deletions(-)

(limited to 'include/linux/of.h')

diff --git a/Documentation/devicetree/of_selftest.txt b/Documentation/devicetree/of_selftest.txt
index 1e3d5c92b5e3..57a808b588bf 100644
--- a/Documentation/devicetree/of_selftest.txt
+++ b/Documentation/devicetree/of_selftest.txt
@@ -63,7 +63,6 @@ struct device_node {
     struct  device_node *parent;
     struct  device_node *child;
     struct  device_node *sibling;
-    struct  device_node *allnext;   /* next in list of all nodes */
     ...
  };
 
@@ -99,12 +98,6 @@ child11 -> sibling12 -> sibling13 -> sibling14 -> null
 Figure 1: Generic structure of un-flattened device tree
 
 
-*allnext: it is used to link all the nodes of DT into a list. So, for the
- above tree the list would be as follows:
-
-root->child1->child11->sibling12->sibling13->child131->sibling14->sibling2->
-child21->sibling22->sibling23->sibling3->child31->sibling32->sibling4->null
-
 Before executing OF selftest, it is required to attach the test data to
 machine's device tree (if present). So, when selftest_data_add() is called,
 at first it reads the flattened device tree data linked into the kernel image
@@ -131,11 +124,6 @@ root ('/')
  test-child01      null             null             null
 
 
-allnext list:
-
-root->testcase-data->test-child0->test-child01->test-sibling1->test-sibling2
-->test-sibling3->null
-
 Figure 2: Example test data tree to be attached to live tree.
 
 According to the scenario above, the live tree is already present so it isn't
@@ -204,8 +192,6 @@ detached and then moving up the parent nodes are removed, and eventually the
 whole tree). selftest_data_remove() calls detach_node_and_children() that uses
 of_detach_node() to detach the nodes from the live device tree.
 
-To detach a node, of_detach_node() first updates all_next linked list, by
-attaching the previous node's allnext to current node's allnext pointer. And
-then, it either updates the child pointer of given node's parent to its
-sibling or attaches the previous sibling to the given node's sibling, as
-appropriate. That is it :)
+To detach a node, of_detach_node() either updates the child pointer of given
+node's parent to its sibling or attaches the previous sibling to the given
+node's sibling, as appropriate. That is it :)
diff --git a/Documentation/devicetree/todo.txt b/Documentation/devicetree/todo.txt
index c3cf0659bd19..b5139d1de811 100644
--- a/Documentation/devicetree/todo.txt
+++ b/Documentation/devicetree/todo.txt
@@ -2,7 +2,6 @@ Todo list for devicetree:
 
 === General structure ===
 - Switch from custom lists to (h)list_head for nodes and properties structure
-- Remove of_allnodes list and iterate using list of child nodes alone
 
 === CONFIG_OF_DYNAMIC ===
 - Switch to RCU for tree updates and get rid of global spinlock
diff --git a/drivers/mfd/vexpress-sysreg.c b/drivers/mfd/vexpress-sysreg.c
index 9e21e4fc9599..8f43ab8fd2d6 100644
--- a/drivers/mfd/vexpress-sysreg.c
+++ b/drivers/mfd/vexpress-sysreg.c
@@ -223,7 +223,7 @@ static int vexpress_sysreg_probe(struct platform_device *pdev)
 	vexpress_config_set_master(vexpress_sysreg_get_master());
 
 	/* Confirm board type against DT property, if available */
-	if (of_property_read_u32(of_allnodes, "arm,hbi", &dt_hbi) == 0) {
+	if (of_property_read_u32(of_root, "arm,hbi", &dt_hbi) == 0) {
 		u32 id = vexpress_get_procid(VEXPRESS_SITE_MASTER);
 		u32 hbi = (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
 
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 3823edf2d012..1f61a908a767 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -32,8 +32,8 @@
 
 LIST_HEAD(aliases_lookup);
 
-struct device_node *of_allnodes;
-EXPORT_SYMBOL(of_allnodes);
+struct device_node *of_root;
+EXPORT_SYMBOL(of_root);
 struct device_node *of_chosen;
 struct device_node *of_aliases;
 struct device_node *of_stdout;
@@ -48,7 +48,7 @@ struct kset *of_kset;
  */
 DEFINE_MUTEX(of_mutex);
 
-/* use when traversing tree through the allnext, child, sibling,
+/* use when traversing tree through the child, sibling,
  * or parent members of struct device_node.
  */
 DEFINE_RAW_SPINLOCK(devtree_lock);
@@ -204,7 +204,7 @@ static int __init of_init(void)
 	mutex_unlock(&of_mutex);
 
 	/* Symlink in /proc as required by userspace ABI */
-	if (of_allnodes)
+	if (of_root)
 		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
 
 	return 0;
@@ -245,6 +245,23 @@ struct property *of_find_property(const struct device_node *np,
 }
 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
@@ -259,10 +276,8 @@ struct device_node *of_find_all_nodes(struct device_node *prev)
 	unsigned long flags;
 
 	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;
+	np = __of_find_all_nodes(prev);
+	of_node_get(np);
 	of_node_put(prev);
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
@@ -736,7 +751,7 @@ struct device_node *of_find_node_by_path(const char *path)
 	unsigned long flags;
 
 	if (strcmp(path, "/") == 0)
-		return of_node_get(of_allnodes);
+		return of_node_get(of_root);
 
 	/* The path could begin with an alias */
 	if (*path != '/') {
@@ -761,7 +776,7 @@ struct device_node *of_find_node_by_path(const char *path)
 	/* Step down the tree matching path components */
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	if (!np)
-		np = of_node_get(of_allnodes);
+		np = of_node_get(of_root);
 	while (np && *path == '/') {
 		path++; /* Increment past '/' delimiter */
 		np = __of_find_node_by_path(np, path);
@@ -790,8 +805,7 @@ struct device_node *of_find_node_by_name(struct device_node *from,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	np = from ? from->allnext : of_allnodes;
-	for (; np; np = np->allnext)
+	for_each_of_allnodes_from(from, np)
 		if (np->name && (of_node_cmp(np->name, name) == 0)
 		    && of_node_get(np))
 			break;
@@ -820,8 +834,7 @@ struct device_node *of_find_node_by_type(struct device_node *from,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	np = from ? from->allnext : of_allnodes;
-	for (; np; np = np->allnext)
+	for_each_of_allnodes_from(from, np)
 		if (np->type && (of_node_cmp(np->type, type) == 0)
 		    && of_node_get(np))
 			break;
@@ -852,12 +865,10 @@ struct device_node *of_find_compatible_node(struct device_node *from,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	np = from ? from->allnext : of_allnodes;
-	for (; np; np = np->allnext) {
+	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;
@@ -884,8 +895,7 @@ struct device_node *of_find_node_with_property(struct device_node *from,
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	np = from ? from->allnext : of_allnodes;
-	for (; np; np = np->allnext) {
+	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);
@@ -967,8 +977,7 @@ struct device_node *of_find_matching_node_and_match(struct device_node *from,
 		*match = NULL;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	np = from ? from->allnext : of_allnodes;
-	for (; np; np = np->allnext) {
+	for_each_of_allnodes_from(from, np) {
 		m = __of_match_node(matches, np);
 		if (m && of_node_get(np)) {
 			if (match)
@@ -1025,7 +1034,7 @@ struct device_node *of_find_node_by_phandle(phandle handle)
 		return NULL;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
-	for (np = of_allnodes; np; np = np->allnext)
+	for_each_of_allnodes(np)
 		if (np->phandle == handle)
 			break;
 	of_node_get(np);
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index f297891d8529..da2509d639c8 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -117,8 +117,6 @@ void __of_attach_node(struct device_node *np)
 
 	np->child = NULL;
 	np->sibling = np->parent->child;
-	np->allnext = np->parent->allnext;
-	np->parent->allnext = np;
 	np->parent->child = np;
 	of_node_clear_flag(np, OF_DETACHED);
 }
@@ -154,17 +152,6 @@ void __of_detach_node(struct device_node *np)
 	if (WARN_ON(!parent))
 		return;
 
-	if (of_allnodes == np)
-		of_allnodes = np->allnext;
-	else {
-		struct device_node *prev;
-		for (prev = of_allnodes;
-		     prev->allnext != np;
-		     prev = prev->allnext)
-			;
-		prev->allnext = np->allnext;
-	}
-
 	if (parent->child == np)
 		parent->child = np->sibling;
 	else {
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index d1ffca8b34ea..1d30b9f96466 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -145,15 +145,15 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size,
  * @mem: Memory chunk to use for allocating device nodes and properties
  * @p: pointer to node in flat tree
  * @dad: Parent struct device_node
- * @allnextpp: pointer to ->allnext from last allocated device_node
  * @fpsize: Size of the node path up at the current depth.
  */
 static void * unflatten_dt_node(void *blob,
 				void *mem,
 				int *poffset,
 				struct device_node *dad,
-				struct device_node ***allnextpp,
-				unsigned long fpsize)
+				struct device_node **nodepp,
+				unsigned long fpsize,
+				bool dryrun)
 {
 	const __be32 *p;
 	struct device_node *np;
@@ -200,7 +200,7 @@ static void * unflatten_dt_node(void *blob,
 
 	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
 				__alignof__(struct device_node));
-	if (allnextpp) {
+	if (!dryrun) {
 		char *fn;
 		of_node_init(np);
 		np->full_name = fn = ((char *)np) + sizeof(*np);
@@ -222,8 +222,6 @@ static void * unflatten_dt_node(void *blob,
 		memcpy(fn, pathp, l);
 
 		prev_pp = &np->properties;
-		**allnextpp = np;
-		*allnextpp = &np->allnext;
 		if (dad != NULL) {
 			np->parent = dad;
 			/* we temporarily use the next field as `last_child'*/
@@ -254,7 +252,7 @@ static void * unflatten_dt_node(void *blob,
 			has_name = 1;
 		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 					__alignof__(struct property));
-		if (allnextpp) {
+		if (!dryrun) {
 			/* We accept flattened tree phandles either in
 			 * ePAPR-style "phandle" properties, or the
 			 * legacy "linux,phandle" properties.  If both
@@ -296,7 +294,7 @@ static void * unflatten_dt_node(void *blob,
 		sz = (pa - ps) + 1;
 		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 					__alignof__(struct property));
-		if (allnextpp) {
+		if (!dryrun) {
 			pp->name = "name";
 			pp->length = sz;
 			pp->value = pp + 1;
@@ -308,7 +306,7 @@ static void * unflatten_dt_node(void *blob,
 				(char *)pp->value);
 		}
 	}
-	if (allnextpp) {
+	if (!dryrun) {
 		*prev_pp = NULL;
 		np->name = of_get_property(np, "name", NULL);
 		np->type = of_get_property(np, "device_type", NULL);
@@ -324,11 +322,13 @@ static void * unflatten_dt_node(void *blob,
 	if (depth < 0)
 		depth = 0;
 	while (*poffset > 0 && depth > old_depth)
-		mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp,
-					fpsize);
+		mem = unflatten_dt_node(blob, mem, poffset, np, NULL,
+					fpsize, dryrun);
 
 	if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
 		pr_err("unflatten: error %d processing FDT\n", *poffset);
+	if (nodepp)
+		*nodepp = np;
 
 	return mem;
 }
@@ -352,7 +352,6 @@ static void __unflatten_device_tree(void *blob,
 	unsigned long size;
 	int start;
 	void *mem;
-	struct device_node **allnextp = mynodes;
 
 	pr_debug(" -> unflatten_device_tree()\n");
 
@@ -373,7 +372,7 @@ static void __unflatten_device_tree(void *blob,
 
 	/* First pass, scan for size */
 	start = 0;
-	size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0);
+	size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0, true);
 	size = ALIGN(size, 4);
 
 	pr_debug("  size is %lx, allocating...\n", size);
@@ -388,11 +387,10 @@ static void __unflatten_device_tree(void *blob,
 
 	/* Second pass, do actual unflattening */
 	start = 0;
-	unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
+	unflatten_dt_node(blob, mem, &start, NULL, mynodes, 0, false);
 	if (be32_to_cpup(mem + size) != 0xdeadbeef)
 		pr_warning("End of tree marker overwritten: %08x\n",
 			   be32_to_cpup(mem + size));
-	*allnextp = NULL;
 
 	pr_debug(" <- unflatten_device_tree()\n");
 }
@@ -1041,7 +1039,7 @@ bool __init early_init_dt_scan(void *params)
  */
 void __init unflatten_device_tree(void)
 {
-	__unflatten_device_tree(initial_boot_params, &of_allnodes,
+	__unflatten_device_tree(initial_boot_params, &of_root,
 				early_init_dt_alloc_memory_arch);
 
 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 36b4035881b0..d2acae825af9 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -25,8 +25,7 @@
 
 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
 
-void __initdata (*of_pdt_build_more)(struct device_node *dp,
-		struct device_node ***nextp);
+void __initdata (*of_pdt_build_more)(struct device_node *dp);
 
 #if defined(CONFIG_SPARC)
 unsigned int of_pdt_unique_id __initdata;
@@ -192,8 +191,7 @@ static struct device_node * __init of_pdt_create_node(phandle node,
 }
 
 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
-						   phandle node,
-						   struct device_node ***nextp)
+						   phandle node)
 {
 	struct device_node *ret = NULL, *prev_sibling = NULL;
 	struct device_node *dp;
@@ -210,16 +208,12 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
 			ret = dp;
 		prev_sibling = dp;
 
-		*(*nextp) = dp;
-		*nextp = &dp->allnext;
-
 		dp->full_name = of_pdt_build_full_name(dp);
 
-		dp->child = of_pdt_build_tree(dp,
-				of_pdt_prom_ops->getchild(node), nextp);
+		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
 
 		if (of_pdt_build_more)
-			of_pdt_build_more(dp, nextp);
+			of_pdt_build_more(dp);
 
 		node = of_pdt_prom_ops->getsibling(node);
 	}
@@ -234,20 +228,17 @@ static void * __init kernel_tree_alloc(u64 size, u64 align)
 
 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 {
-	struct device_node **nextp;
-
 	BUG_ON(!ops);
 	of_pdt_prom_ops = ops;
 
-	of_allnodes = of_pdt_create_node(root_node, NULL);
+	of_root = of_pdt_create_node(root_node, NULL);
 #if defined(CONFIG_SPARC)
-	of_allnodes->path_component_name = "";
+	of_root->path_component_name = "";
 #endif
-	of_allnodes->full_name = "/";
+	of_root->full_name = "/";
 
-	nextp = &of_allnodes->allnext;
-	of_allnodes->child = of_pdt_build_tree(of_allnodes,
-			of_pdt_prom_ops->getchild(of_allnodes->phandle), &nextp);
+	of_root->child = of_pdt_build_tree(of_root,
+				of_pdt_prom_ops->getchild(of_root->phandle));
 
 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 	of_alias_scan(kernel_tree_alloc);
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index 11b873c54a77..bf7d99317a94 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -148,7 +148,7 @@ static void __init of_selftest_dynamic(void)
 
 static int __init of_selftest_check_node_linkage(struct device_node *np)
 {
-	struct device_node *child, *allnext_index = np;
+	struct device_node *child;
 	int count = 0, rc;
 
 	for_each_child_of_node(np, child) {
@@ -158,14 +158,6 @@ static int __init of_selftest_check_node_linkage(struct device_node *np)
 			return -EINVAL;
 		}
 
-		while (allnext_index && allnext_index != child)
-			allnext_index = allnext_index->allnext;
-		if (allnext_index != child) {
-			pr_err("Node %s is ordered differently in sibling and allnode lists\n",
-				 child->name);
-			return -EINVAL;
-		}
-
 		rc = of_selftest_check_node_linkage(child);
 		if (rc < 0)
 			return rc;
@@ -180,12 +172,12 @@ static void __init of_selftest_check_tree_linkage(void)
 	struct device_node *np;
 	int allnode_count = 0, child_count;
 
-	if (!of_allnodes)
+	if (!of_root)
 		return;
 
 	for_each_of_allnodes(np)
 		allnode_count++;
-	child_count = of_selftest_check_node_linkage(of_allnodes);
+	child_count = of_selftest_check_node_linkage(of_root);
 
 	selftest(child_count > 0, "Device node data structure is corrupted\n");
 	selftest(child_count == allnode_count, "allnodes list size (%i) doesn't match"
@@ -775,33 +767,29 @@ static void update_node_properties(struct device_node *np,
  */
 static int attach_node_and_children(struct device_node *np)
 {
-	struct device_node *next, *root = np, *dup;
+	struct device_node *next, *dup, *child;
 
-	/* skip root node */
-	np = np->child;
-	/* storing a copy in temporary node */
-	dup = np;
+	dup = of_find_node_by_path(np->full_name);
+	if (dup) {
+		update_node_properties(np, dup);
+		return 0;
+	}
 
-	while (dup) {
+	/* Children of the root need to be remembered for removal */
+	if (np->parent == of_root) {
 		if (WARN_ON(last_node_index >= NO_OF_NODES))
 			return -EINVAL;
-		nodes[last_node_index++] = dup;
-		dup = dup->sibling;
+		nodes[last_node_index++] = np;
 	}
-	dup = NULL;
 
-	while (np) {
-		next = np->allnext;
-		dup = of_find_node_by_path(np->full_name);
-		if (dup)
-			update_node_properties(np, dup);
-		else {
-			np->child = NULL;
-			if (np->parent == root)
-				np->parent = of_allnodes;
-			of_attach_node(np);
-		}
-		np = next;
+	child = np->child;
+	np->child = NULL;
+	np->sibling = NULL;
+	of_attach_node(np);
+	while (child) {
+		next = child->sibling;
+		attach_node_and_children(child);
+		child = next;
 	}
 
 	return 0;
@@ -846,10 +834,10 @@ static int __init selftest_data_add(void)
 		return -EINVAL;
 	}
 
-	if (!of_allnodes) {
+	if (!of_root) {
 		/* enabling flag for removing nodes */
 		selftest_live_tree = true;
-		of_allnodes = selftest_data_node;
+		of_root = selftest_data_node;
 
 		for_each_of_allnodes(np)
 			__of_attach_node_sysfs(np);
@@ -859,7 +847,14 @@ static int __init selftest_data_add(void)
 	}
 
 	/* attach the sub-tree to live tree */
-	return attach_node_and_children(selftest_data_node);
+	np = selftest_data_node->child;
+	while (np) {
+		struct device_node *next = np->sibling;
+		np->parent = of_root;
+		attach_node_and_children(np);
+		np = next;
+	}
+	return 0;
 }
 
 /**
@@ -889,10 +884,10 @@ static void selftest_data_remove(void)
 		of_node_put(of_chosen);
 		of_aliases = NULL;
 		of_chosen = NULL;
-		for_each_child_of_node(of_allnodes, np)
+		for_each_child_of_node(of_root, np)
 			detach_node_and_children(np);
-		__of_detach_node_sysfs(of_allnodes);
-		of_allnodes = NULL;
+		__of_detach_node_sysfs(of_root);
+		of_root = NULL;
 		return;
 	}
 
diff --git a/include/linux/of.h b/include/linux/of.h
index 30912939a610..f54da3b699a8 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -56,7 +56,6 @@ struct device_node {
 	struct	device_node *child;
 	struct	device_node *sibling;
 	struct	device_node *next;	/* next device of same type */
-	struct	device_node *allnext;	/* next in list of all nodes */
 	struct	kobject kobj;
 	unsigned long _flags;
 	void	*data;
@@ -108,7 +107,7 @@ static inline void of_node_put(struct device_node *node) { }
 #ifdef CONFIG_OF
 
 /* Pointer for first entry in chain of all nodes. */
-extern struct device_node *of_allnodes;
+extern struct device_node *of_root;
 extern struct device_node *of_chosen;
 extern struct device_node *of_aliases;
 extern struct device_node *of_stdout;
@@ -116,7 +115,7 @@ extern raw_spinlock_t devtree_lock;
 
 static inline bool of_have_populated_dt(void)
 {
-	return of_allnodes != NULL;
+	return of_root != NULL;
 }
 
 static inline bool of_node_is_root(const struct device_node *node)
@@ -160,6 +159,7 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag
 	clear_bit(flag, &p->_flags);
 }
 
+extern struct device_node *__of_find_all_nodes(struct device_node *prev);
 extern struct device_node *of_find_all_nodes(struct device_node *prev);
 
 /*
@@ -215,8 +215,9 @@ static inline const char *of_node_full_name(const struct device_node *np)
 	return np ? np->full_name : "<no-node>";
 }
 
-#define for_each_of_allnodes(dn) \
-	for (dn = of_allnodes; dn; dn = dn->allnext)
+#define for_each_of_allnodes_from(from, dn) \
+	for (dn = __of_find_all_nodes(from); dn; dn = __of_find_all_nodes(dn))
+#define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn)
 extern struct device_node *of_find_node_by_name(struct device_node *from,
 	const char *name);
 extern struct device_node *of_find_node_by_type(struct device_node *from,
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
index c65a18a0cfdf..7e09244bb679 100644
--- a/include/linux/of_pdt.h
+++ b/include/linux/of_pdt.h
@@ -39,7 +39,6 @@ extern void *prom_early_alloc(unsigned long size);
 /* for building the device tree */
 extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
 
-extern void (*of_pdt_build_more)(struct device_node *dp,
-		struct device_node ***nextp);
+extern void (*of_pdt_build_more)(struct device_node *dp);
 
 #endif /* _LINUX_OF_PDT_H */
-- 
cgit v1.2.3-55-g7522


From 5f563585ab0afa8c35b3627d65c07966f7a5080e Mon Sep 17 00:00:00 2001
From: Thierry Reding
Date: Thu, 2 Oct 2014 16:01:10 +0200
Subject: of: Fix padding in _OF_DECLARE macro definition

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 include/linux/of.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'include/linux/of.h')

diff --git a/include/linux/of.h b/include/linux/of.h
index f54da3b699a8..3c851a8f23eb 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -836,7 +836,7 @@ static inline int of_get_available_child_count(const struct device_node *np)
 		 = { .compatible = compat,				\
 		     .data = (fn == (fn_type)NULL) ? fn : fn  }
 #else
-#define _OF_DECLARE(table, name, compat, fn, fn_type)					\
+#define _OF_DECLARE(table, name, compat, fn, fn_type)			\
 	static const struct of_device_id __of_table_##name		\
 		__attribute__((unused))					\
 		 = { .compatible = compat,				\
-- 
cgit v1.2.3-55-g7522


From 53a4ab96c61a34d62717b1481f6043e0b4338d74 Mon Sep 17 00:00:00 2001
From: Kevin Cernekee
Date: Wed, 12 Nov 2014 12:54:01 -0800
Subject: of: Change of_device_is_available() to return bool

This function can only return true or false; using a bool makes it more
obvious to the reader.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 drivers/of/base.c  | 22 +++++++++++-----------
 include/linux/of.h |  6 +++---
 2 files changed, 14 insertions(+), 14 deletions(-)

(limited to 'include/linux/of.h')

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 4627e0acf4ad..2d5dfb8b2e65 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -522,27 +522,27 @@ EXPORT_SYMBOL(of_machine_is_compatible);
  *
  *  @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
+ *  Returns true if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
  */
-static int __of_device_is_available(const struct device_node *device)
+static bool __of_device_is_available(const struct device_node *device)
 {
 	const char *status;
 	int statlen;
 
 	if (!device)
-		return 0;
+		return false;
 
 	status = __of_get_property(device, "status", &statlen);
 	if (status == NULL)
-		return 1;
+		return true;
 
 	if (statlen > 0) {
 		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
-			return 1;
+			return true;
 	}
 
-	return 0;
+	return false;
 }
 
 /**
@@ -550,13 +550,13 @@ static int __of_device_is_available(const struct device_node *device)
  *
  *  @device: Node to check for availability
  *
- *  Returns 1 if the status property is absent or set to "okay" or "ok",
- *  0 otherwise
+ *  Returns true if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
  */
-int of_device_is_available(const struct device_node *device)
+bool of_device_is_available(const struct device_node *device)
 {
 	unsigned long flags;
-	int res;
+	bool res;
 
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	res = __of_device_is_available(device);
diff --git a/include/linux/of.h b/include/linux/of.h
index 3c851a8f23eb..27635c89d8c2 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -276,7 +276,7 @@ extern int of_property_read_string_helper(struct device_node *np,
 					      const char **out_strs, size_t sz, int index);
 extern int of_device_is_compatible(const struct device_node *device,
 				   const char *);
-extern int of_device_is_available(const struct device_node *device);
+extern bool of_device_is_available(const struct device_node *device);
 extern const void *of_get_property(const struct device_node *node,
 				const char *name,
 				int *lenp);
@@ -427,9 +427,9 @@ static inline int of_device_is_compatible(const struct device_node *device,
 	return 0;
 }
 
-static inline int of_device_is_available(const struct device_node *device)
+static inline bool of_device_is_available(const struct device_node *device)
 {
-	return 0;
+	return false;
 }
 
 static inline struct property *of_find_property(const struct device_node *np,
-- 
cgit v1.2.3-55-g7522


From b53a2340d0d30468b7315992ba77fe188c3bc5c8 Mon Sep 17 00:00:00 2001
From: Pantelis Antoniou
Date: Tue, 28 Oct 2014 22:33:53 +0200
Subject: of/reconfig: Add of_reconfig_get_state_change() of notifier helper.

Introduce of_reconfig_get_state_change() which allows an of notifier
to query about device state changes.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 drivers/of/dynamic.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h   |  7 ++++
 2 files changed, 103 insertions(+)

(limited to 'include/linux/of.h')

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 661ad2f5c00c..6659c39ab3aa 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -85,6 +85,102 @@ int of_reconfig_notify(unsigned long action, void *p)
 	return notifier_to_errno(rc);
 }
 
+/*
+ * of_reconfig_get_state_change()	- Returns new state of device
+ * @action	- action of the of notifier
+ * @arg		- argument of the of notifier
+ *
+ * Returns the new state of a device based on the notifier used.
+ * Returns 0 on device going from enabled to disabled, 1 on device
+ * going from disabled to enabled and -1 on no change.
+ */
+int of_reconfig_get_state_change(unsigned long action, void *arg)
+{
+	struct device_node *dn;
+	struct property *prop, *old_prop;
+	struct of_prop_reconfig *pr;
+	int is_status, status_state, old_status_state, prev_state, new_state;
+
+	/* figure out if a device should be created or destroyed */
+	dn = NULL;
+	prop = old_prop = NULL;
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		dn = arg;
+		prop = of_find_property(dn, "status", NULL);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		pr = arg;
+		dn = pr->dn;
+		prop = pr->prop;
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		pr = arg;
+		dn = pr->dn;
+		prop = pr->prop;
+		old_prop = pr->old_prop;
+		break;
+	default:
+		return OF_RECONFIG_NO_CHANGE;
+	}
+
+	is_status = 0;
+	status_state = -1;
+	old_status_state = -1;
+	prev_state = -1;
+	new_state = -1;
+
+	if (prop && !strcmp(prop->name, "status")) {
+		is_status = 1;
+		status_state = !strcmp(prop->value, "okay") ||
+			       !strcmp(prop->value, "ok");
+		if (old_prop)
+			old_status_state = !strcmp(old_prop->value, "okay") ||
+					   !strcmp(old_prop->value, "ok");
+	}
+
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		prev_state = 0;
+		/* -1 & 0 status either missing or okay */
+		new_state = status_state != 0;
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		/* -1 & 0 status either missing or okay */
+		prev_state = status_state != 0;
+		new_state = 0;
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		if (is_status) {
+			/* no status property -> enabled (legacy) */
+			prev_state = 1;
+			new_state = status_state;
+		}
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		if (is_status) {
+			prev_state = status_state;
+			/* no status property -> enabled (legacy) */
+			new_state = 1;
+		}
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		if (is_status) {
+			prev_state = old_status_state != 0;
+			new_state = status_state != 0;
+		}
+		break;
+	}
+
+	if (prev_state == new_state)
+		return OF_RECONFIG_NO_CHANGE;
+
+	return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
+}
+EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
+
 int of_property_notify(int action, struct device_node *np,
 		       struct property *prop, struct property *oldprop)
 {
diff --git a/include/linux/of.h b/include/linux/of.h
index 27635c89d8c2..8e3a264c869c 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -327,6 +327,7 @@ struct of_prop_reconfig {
 extern int of_reconfig_notifier_register(struct notifier_block *);
 extern int of_reconfig_notifier_unregister(struct notifier_block *);
 extern int of_reconfig_notify(unsigned long, void *);
+extern int of_reconfig_get_state_change(unsigned long action, void *arg);
 
 extern int of_attach_node(struct device_node *);
 extern int of_detach_node(struct device_node *);
@@ -887,6 +888,12 @@ struct of_changeset {
 	struct list_head entries;
 };
 
+enum of_reconfig_change {
+	OF_RECONFIG_NO_CHANGE = 0,
+	OF_RECONFIG_CHANGE_ADD,
+	OF_RECONFIG_CHANGE_REMOVE,
+};
+
 #ifdef CONFIG_OF_DYNAMIC
 extern void of_changeset_init(struct of_changeset *ocs);
 extern void of_changeset_destroy(struct of_changeset *ocs);
-- 
cgit v1.2.3-55-g7522


From f6892d193fb9d694a1b50550649ba6e82f8abec1 Mon Sep 17 00:00:00 2001
From: Grant Likely
Date: Fri, 21 Nov 2014 15:14:58 +0000
Subject: of/reconfig: Add empty stubs for the of_reconfig methods

To simplify subsystem setup code, make empty stubs for the
of_reconfig_*() methods. This is particularly useful for registering and
unregistering the notifiers so that it doesn't impact the flow of the
subsystem setup code.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 include/linux/of.h | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

(limited to 'include/linux/of.h')

diff --git a/include/linux/of.h b/include/linux/of.h
index 8e3a264c869c..b59ee21933a4 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -324,11 +324,6 @@ struct of_prop_reconfig {
 	struct property		*old_prop;
 };
 
-extern int of_reconfig_notifier_register(struct notifier_block *);
-extern int of_reconfig_notifier_unregister(struct notifier_block *);
-extern int of_reconfig_notify(unsigned long, void *);
-extern int of_reconfig_get_state_change(unsigned long action, void *arg);
-
 extern int of_attach_node(struct device_node *);
 extern int of_detach_node(struct device_node *);
 
@@ -895,6 +890,11 @@ enum of_reconfig_change {
 };
 
 #ifdef CONFIG_OF_DYNAMIC
+extern int of_reconfig_notifier_register(struct notifier_block *);
+extern int of_reconfig_notifier_unregister(struct notifier_block *);
+extern int of_reconfig_notify(unsigned long, void *);
+extern int of_reconfig_get_state_change(unsigned long action, void *arg);
+
 extern void of_changeset_init(struct of_changeset *ocs);
 extern void of_changeset_destroy(struct of_changeset *ocs);
 extern int of_changeset_apply(struct of_changeset *ocs);
@@ -932,7 +932,24 @@ static inline int of_changeset_update_property(struct of_changeset *ocs,
 {
 	return of_changeset_action(ocs, OF_RECONFIG_UPDATE_PROPERTY, np, prop);
 }
-#endif
+#else /* CONFIG_OF_DYNAMIC */
+static inline int of_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return -EINVAL;
+}
+static inline int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return -EINVAL;
+}
+static inline int of_reconfig_notify(unsigned long action, void *arg)
+{
+	return -EINVAL;
+}
+static inline int of_reconfig_get_state_change(unsigned long action, void *arg)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_OF_DYNAMIC */
 
 /* CONFIG_OF_RESOLVE api */
 extern int of_resolve_phandles(struct device_node *tree);
-- 
cgit v1.2.3-55-g7522


From f5242e5a883bf1c1aba6bfd87b85e7dda0e62191 Mon Sep 17 00:00:00 2001
From: Grant Likely
Date: Mon, 24 Nov 2014 17:58:01 +0000
Subject: of/reconfig: Always use the same structure for notifiers

The OF_RECONFIG notifier callback uses a different structure depending
on whether it is a node change or a property change. This is silly, and
not very safe. Rework the code to use the same data structure regardless
of the type of notifier.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: <linuxppc-dev@lists.ozlabs.org>
---
 arch/powerpc/mm/numa.c                          |  3 +-
 arch/powerpc/platforms/pseries/hotplug-cpu.c    |  7 +++--
 arch/powerpc/platforms/pseries/hotplug-memory.c | 15 +++++----
 arch/powerpc/platforms/pseries/iommu.c          |  5 +--
 arch/powerpc/platforms/pseries/setup.c          |  5 +--
 drivers/crypto/nx/nx-842.c                      |  4 +--
 drivers/of/dynamic.c                            | 41 +++++++++++++------------
 include/linux/of.h                              | 23 ++++++++------
 8 files changed, 54 insertions(+), 49 deletions(-)

(limited to 'include/linux/of.h')

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index b9d1dfdbe5bb..9fe6002c1d5a 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1711,12 +1711,11 @@ static void stage_topology_update(int core_id)
 static int dt_update_callback(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
-	struct of_prop_reconfig *update;
+	struct of_reconfig_data *update = data;
 	int rc = NOTIFY_DONE;
 
 	switch (action) {
 	case OF_RECONFIG_UPDATE_PROPERTY:
-		update = (struct of_prop_reconfig *)data;
 		if (!of_prop_cmp(update->dn->type, "cpu") &&
 		    !of_prop_cmp(update->prop->name, "ibm,associativity")) {
 			u32 core_id;
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 5c375f93c669..f30cf4d136a4 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -340,16 +340,17 @@ static void pseries_remove_processor(struct device_node *np)
 }
 
 static int pseries_smp_notifier(struct notifier_block *nb,
-				unsigned long action, void *node)
+				unsigned long action, void *data)
 {
+	struct of_reconfig_data *rd = data;
 	int err = 0;
 
 	switch (action) {
 	case OF_RECONFIG_ATTACH_NODE:
-		err = pseries_add_processor(node);
+		err = pseries_add_processor(rd->dn);
 		break;
 	case OF_RECONFIG_DETACH_NODE:
-		pseries_remove_processor(node);
+		pseries_remove_processor(rd->dn);
 		break;
 	}
 	return notifier_from_errno(err);
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 3c4c0dcd90d3..1bbb78fab530 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -183,7 +183,7 @@ static int pseries_add_mem_node(struct device_node *np)
 	return (ret < 0) ? -EINVAL : 0;
 }
 
-static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
+static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 {
 	struct of_drconf_cell *new_drmem, *old_drmem;
 	unsigned long memblock_size;
@@ -232,22 +232,21 @@ static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
 }
 
 static int pseries_memory_notifier(struct notifier_block *nb,
-				   unsigned long action, void *node)
+				   unsigned long action, void *data)
 {
-	struct of_prop_reconfig *pr;
+	struct of_reconfig_data *rd = data;
 	int err = 0;
 
 	switch (action) {
 	case OF_RECONFIG_ATTACH_NODE:
-		err = pseries_add_mem_node(node);
+		err = pseries_add_mem_node(rd->dn);
 		break;
 	case OF_RECONFIG_DETACH_NODE:
-		err = pseries_remove_mem_node(node);
+		err = pseries_remove_mem_node(rd->dn);
 		break;
 	case OF_RECONFIG_UPDATE_PROPERTY:
-		pr = (struct of_prop_reconfig *)node;
-		if (!strcmp(pr->prop->name, "ibm,dynamic-memory"))
-			err = pseries_update_drconf_memory(pr);
+		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
+			err = pseries_update_drconf_memory(rd);
 		break;
 	}
 	return notifier_from_errno(err);
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index e32e00976a94..3e5bfdafee63 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1251,10 +1251,11 @@ static struct notifier_block iommu_mem_nb = {
 	.notifier_call = iommu_mem_notifier,
 };
 
-static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
+static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *data)
 {
 	int err = NOTIFY_OK;
-	struct device_node *np = node;
+	struct of_reconfig_data *rd = data;
+	struct device_node *np = rd->dn;
 	struct pci_dn *pci = PCI_DN(np);
 	struct direct_window *window;
 
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 125c589eeef5..ed8a90022a3d 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -251,9 +251,10 @@ static void __init pseries_discover_pic(void)
 	       " interrupt-controller\n");
 }
 
-static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
+static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *data)
 {
-	struct device_node *np = node;
+	struct of_reconfig_data *rd = data;
+	struct device_node *np = rd->dn;
 	struct pci_dn *pci = NULL;
 	int err = NOTIFY_OK;
 
diff --git a/drivers/crypto/nx/nx-842.c b/drivers/crypto/nx/nx-842.c
index 061407d59520..887196e9b50c 100644
--- a/drivers/crypto/nx/nx-842.c
+++ b/drivers/crypto/nx/nx-842.c
@@ -1009,9 +1009,9 @@ error_out:
  *		notifier_to_errno() to decode this value
  */
 static int nx842_OF_notifier(struct notifier_block *np, unsigned long action,
-			     void *update)
+			     void *data)
 {
-	struct of_prop_reconfig *upd = update;
+	struct of_reconfig_data *upd = data;
 	struct nx842_devdata *local_devdata;
 	struct device_node *node = NULL;
 
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index cc106529dca8..3351ef408125 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -87,18 +87,17 @@ const char *action_names[] = {
 };
 #endif
 
-int of_reconfig_notify(unsigned long action, void *p)
+int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
 {
 	int rc;
 #ifdef DEBUG
-	struct device_node *dn = p;
-	struct of_prop_reconfig *pr = p;
+	struct of_reconfig_data *pr = p;
 
 	switch (action) {
 	case OF_RECONFIG_ATTACH_NODE:
 	case OF_RECONFIG_DETACH_NODE:
 		pr_debug("of/notify %-15s %s\n", action_names[action],
-			dn->full_name);
+			pr->dn->full_name);
 		break;
 	case OF_RECONFIG_ADD_PROPERTY:
 	case OF_RECONFIG_REMOVE_PROPERTY:
@@ -122,31 +121,22 @@ int of_reconfig_notify(unsigned long action, void *p)
  * Returns 0 on device going from enabled to disabled, 1 on device
  * going from disabled to enabled and -1 on no change.
  */
-int of_reconfig_get_state_change(unsigned long action, void *arg)
+int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
 {
-	struct device_node *dn;
-	struct property *prop, *old_prop;
-	struct of_prop_reconfig *pr;
+	struct property *prop, *old_prop = NULL;
 	int is_status, status_state, old_status_state, prev_state, new_state;
 
 	/* figure out if a device should be created or destroyed */
-	dn = NULL;
-	prop = old_prop = NULL;
 	switch (action) {
 	case OF_RECONFIG_ATTACH_NODE:
 	case OF_RECONFIG_DETACH_NODE:
-		dn = arg;
-		prop = of_find_property(dn, "status", NULL);
+		prop = of_find_property(pr->dn, "status", NULL);
 		break;
 	case OF_RECONFIG_ADD_PROPERTY:
 	case OF_RECONFIG_REMOVE_PROPERTY:
-		pr = arg;
-		dn = pr->dn;
 		prop = pr->prop;
 		break;
 	case OF_RECONFIG_UPDATE_PROPERTY:
-		pr = arg;
-		dn = pr->dn;
 		prop = pr->prop;
 		old_prop = pr->old_prop;
 		break;
@@ -212,7 +202,7 @@ EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
 int of_property_notify(int action, struct device_node *np,
 		       struct property *prop, struct property *oldprop)
 {
-	struct of_prop_reconfig pr;
+	struct of_reconfig_data pr;
 
 	/* only call notifiers if the node is attached */
 	if (!of_node_is_attached(np))
@@ -250,8 +240,12 @@ void __of_attach_node(struct device_node *np)
  */
 int of_attach_node(struct device_node *np)
 {
+	struct of_reconfig_data rd;
 	unsigned long flags;
 
+	memset(&rd, 0, sizeof(rd));
+	rd.dn = np;
+
 	mutex_lock(&of_mutex);
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	__of_attach_node(np);
@@ -260,7 +254,7 @@ int of_attach_node(struct device_node *np)
 	__of_attach_node_sysfs(np);
 	mutex_unlock(&of_mutex);
 
-	of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
+	of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
 
 	return 0;
 }
@@ -298,9 +292,13 @@ void __of_detach_node(struct device_node *np)
  */
 int of_detach_node(struct device_node *np)
 {
+	struct of_reconfig_data rd;
 	unsigned long flags;
 	int rc = 0;
 
+	memset(&rd, 0, sizeof(rd));
+	rd.dn = np;
+
 	mutex_lock(&of_mutex);
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	__of_detach_node(np);
@@ -309,7 +307,7 @@ int of_detach_node(struct device_node *np)
 	__of_detach_node_sysfs(np);
 	mutex_unlock(&of_mutex);
 
-	of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
+	of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
 
 	return rc;
 }
@@ -505,6 +503,7 @@ static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
 
 static void __of_changeset_entry_notify(struct of_changeset_entry *ce, bool revert)
 {
+	struct of_reconfig_data rd;
 	struct of_changeset_entry ce_inverted;
 	int ret;
 
@@ -516,7 +515,9 @@ static void __of_changeset_entry_notify(struct of_changeset_entry *ce, bool reve
 	switch (ce->action) {
 	case OF_RECONFIG_ATTACH_NODE:
 	case OF_RECONFIG_DETACH_NODE:
-		ret = of_reconfig_notify(ce->action, ce->np);
+		memset(&rd, 0, sizeof(rd));
+		rd.dn = ce->np;
+		ret = of_reconfig_notify(ce->action, &rd);
 		break;
 	case OF_RECONFIG_ADD_PROPERTY:
 	case OF_RECONFIG_REMOVE_PROPERTY:
diff --git a/include/linux/of.h b/include/linux/of.h
index b59ee21933a4..fe1dec87fd68 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -73,6 +73,12 @@ struct of_phandle_args {
 	uint32_t args[MAX_PHANDLE_ARGS];
 };
 
+struct of_reconfig_data {
+	struct device_node	*dn;
+	struct property		*prop;
+	struct property		*old_prop;
+};
+
 /* initialize a node */
 extern struct kobj_type of_node_ktype;
 static inline void of_node_init(struct device_node *node)
@@ -318,12 +324,6 @@ extern int of_update_property(struct device_node *np, struct property *newprop);
 #define OF_RECONFIG_REMOVE_PROPERTY	0x0004
 #define OF_RECONFIG_UPDATE_PROPERTY	0x0005
 
-struct of_prop_reconfig {
-	struct device_node	*dn;
-	struct property		*prop;
-	struct property		*old_prop;
-};
-
 extern int of_attach_node(struct device_node *);
 extern int of_detach_node(struct device_node *);
 
@@ -892,8 +892,9 @@ enum of_reconfig_change {
 #ifdef CONFIG_OF_DYNAMIC
 extern int of_reconfig_notifier_register(struct notifier_block *);
 extern int of_reconfig_notifier_unregister(struct notifier_block *);
-extern int of_reconfig_notify(unsigned long, void *);
-extern int of_reconfig_get_state_change(unsigned long action, void *arg);
+extern int of_reconfig_notify(unsigned long, struct of_reconfig_data *rd);
+extern int of_reconfig_get_state_change(unsigned long action,
+					struct of_reconfig_data *arg);
 
 extern void of_changeset_init(struct of_changeset *ocs);
 extern void of_changeset_destroy(struct of_changeset *ocs);
@@ -941,11 +942,13 @@ static inline int of_reconfig_notifier_unregister(struct notifier_block *nb)
 {
 	return -EINVAL;
 }
-static inline int of_reconfig_notify(unsigned long action, void *arg)
+static inline int of_reconfig_notify(unsigned long action,
+				     struct of_reconfig_data *arg)
 {
 	return -EINVAL;
 }
-static inline int of_reconfig_get_state_change(unsigned long action, void *arg)
+static inline int of_reconfig_get_state_change(unsigned long action,
+						struct of_reconfig_data *arg)
 {
 	return -EINVAL;
 }
-- 
cgit v1.2.3-55-g7522


From 7518b5890d8ac366faa2326ce2356ef6392ce63d Mon Sep 17 00:00:00 2001
From: Pantelis Antoniou
Date: Tue, 28 Oct 2014 22:35:58 +0200
Subject: of/overlay: Introduce DT overlay support

Overlays are a method to dynamically modify part of the kernel's
device tree with dynamically loaded data. Add the core functionality to
parse, apply and remove an overlay changeset. The core functionality
takes care of managing the overlay data format and performing the add
and remove. Drivers are expected to use the overlay functionality to
support custom expansion busses commonly found on consumer development
boards like the BeagleBone or Raspberry Pi.

The overlay code uses CONFIG_OF_DYNAMIC changesets to perform the low
level work of modifying the devicetree.

Documentation about internal and APIs is provided in
	Documentation/devicetree/overlay-notes.txt

v2:
- Switch from __of_node_alloc() to __of_node_dup()
- Documentation fixups
- Remove 2-pass processing of properties
- Remove separate ov_lock; just use the DT mutex.
v1:
- Drop delete capability using '-' prefix. The '-' prefixed names
are valid properties and nodes and there is no need for it just yet.
- Do not update special properties - name & phandle ones.
- Change order of node attachment, so that the special property update
works.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 Documentation/devicetree/overlay-notes.txt | 133 +++++++
 drivers/of/Kconfig                         |   7 +
 drivers/of/Makefile                        |   1 +
 drivers/of/overlay.c                       | 562 +++++++++++++++++++++++++++++
 include/linux/of.h                         |  31 ++
 5 files changed, 734 insertions(+)
 create mode 100644 Documentation/devicetree/overlay-notes.txt
 create mode 100644 drivers/of/overlay.c

(limited to 'include/linux/of.h')

diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt
new file mode 100644
index 000000000000..30ae758e3eef
--- /dev/null
+++ b/Documentation/devicetree/overlay-notes.txt
@@ -0,0 +1,133 @@
+Device Tree Overlay Notes
+-------------------------
+
+This document describes the implementation of the in-kernel
+device tree overlay functionality residing in drivers/of/overlay.c and is a
+companion document to Documentation/devicetree/dt-object-internal.txt[1] &
+Documentation/devicetree/dynamic-resolution-notes.txt[2]
+
+How overlays work
+-----------------
+
+A Device Tree's overlay purpose is to modify the kernel's live tree, and
+have the modification affecting the state of the the kernel in a way that
+is reflecting the changes.
+Since the kernel mainly deals with devices, any new device node that result
+in an active device should have it created while if the device node is either
+disabled or removed all together, the affected device should be deregistered.
+
+Lets take an example where we have a foo board with the following base tree
+which is taken from [1].
+
+---- foo.dts -----------------------------------------------------------------
+	/* FOO platform */
+	/ {
+		compatible = "corp,foo";
+
+		/* shared resources */
+		res: res {
+		};
+
+		/* On chip peripherals */
+		ocp: ocp {
+			/* peripherals that are always instantiated */
+			peripheral1 { ... };
+		}
+	};
+---- foo.dts -----------------------------------------------------------------
+
+The overlay bar.dts, when loaded (and resolved as described in [2]) should
+
+---- bar.dts -----------------------------------------------------------------
+/plugin/;	/* allow undefined label references and record them */
+/ {
+	....	/* various properties for loader use; i.e. part id etc. */
+	fragment@0 {
+		target = <&ocp>;
+		__overlay__ {
+			/* bar peripheral */
+			bar {
+				compatible = "corp,bar";
+				... /* various properties and child nodes */
+			}
+		};
+	};
+};
+---- bar.dts -----------------------------------------------------------------
+
+result in foo+bar.dts
+
+---- foo+bar.dts -------------------------------------------------------------
+	/* FOO platform + bar peripheral */
+	/ {
+		compatible = "corp,foo";
+
+		/* shared resources */
+		res: res {
+		};
+
+		/* On chip peripherals */
+		ocp: ocp {
+			/* peripherals that are always instantiated */
+			peripheral1 { ... };
+
+			/* bar peripheral */
+			bar {
+				compatible = "corp,bar";
+				... /* various properties and child nodes */
+			}
+		}
+	};
+---- foo+bar.dts -------------------------------------------------------------
+
+As a result of the the overlay, a new device node (bar) has been created
+so a bar platform device will be registered and if a matching device driver
+is loaded the device will be created as expected.
+
+Overlay in-kernel API
+--------------------------------
+
+The API is quite easy to use.
+
+1. Call of_overlay_create() to create and apply an overlay. The return value
+is a cookie identifying this overlay.
+
+2. Call of_overlay_destroy() to remove and cleanup the overlay previously
+created via the call to of_overlay_create(). Removal of an overlay that
+is stacked by another will not be permitted.
+
+Finally, if you need to remove all overlays in one-go, just call
+of_overlay_destroy_all() which will remove every single one in the correct
+order.
+
+Overlay DTS Format
+------------------
+
+The DTS of an overlay should have the following format:
+
+{
+	/* ignored properties by the overlay */
+
+	fragment@0 {	/* first child node */
+
+		target=<phandle>;	/* phandle target of the overlay */
+	or
+		target-path="/path";	/* target path of the overlay */
+
+		__overlay__ {
+			property-a;	/* add property-a to the target */
+			node-a {	/* add to an existing, or create a node-a */
+				...
+			};
+		};
+	}
+	fragment@1 {	/* second child node */
+		...
+	};
+	/* more fragments follow */
+}
+
+Using the non-phandle based target method allows one to use a base DT which does
+not contain a __symbols__ node, i.e. it was not compiled with the -@ option.
+The __symbols__ node is only required for the target=<phandle> method, since it
+contains the information required to map from a phandle to a tree location.
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index fbe8f8d418f7..18b2e2539f84 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -84,4 +84,11 @@ config OF_RESERVED_MEM
 config OF_RESOLVE
 	bool
 
+config OF_OVERLAY
+	bool
+	depends on OF
+	select OF_DYNAMIC
+	select OF_DEVICE
+	select OF_RESOLVE
+
 endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index d90553fcd37f..7563f36c71db 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_OF_PCI_IRQ)  += of_pci_irq.o
 obj-$(CONFIG_OF_MTD)	+= of_mtd.o
 obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
 obj-$(CONFIG_OF_RESOLVE)  += resolver.o
+obj-$(CONFIG_OF_OVERLAY) += overlay.o
 
 CFLAGS_fdt.o = -I$(src)/../../scripts/dtc/libfdt
 CFLAGS_fdt_address.o = -I$(src)/../../scripts/dtc/libfdt
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
new file mode 100644
index 000000000000..ea63fbd228ed
--- /dev/null
+++ b/drivers/of/overlay.c
@@ -0,0 +1,562 @@
+/*
+ * Functions for working with device tree overlays
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+#undef DEBUG
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+
+#include "of_private.h"
+
+/**
+ * struct of_overlay_info - Holds a single overlay info
+ * @target:	target of the overlay operation
+ * @overlay:	pointer to the overlay contents node
+ *
+ * Holds a single overlay state, including all the overlay logs &
+ * records.
+ */
+struct of_overlay_info {
+	struct device_node *target;
+	struct device_node *overlay;
+};
+
+/**
+ * struct of_overlay - Holds a complete overlay transaction
+ * @node:	List on which we are located
+ * @count:	Count of ovinfo structures
+ * @ovinfo_tab:	Overlay info table (count sized)
+ * @cset:	Changeset to be used
+ *
+ * Holds a complete overlay transaction
+ */
+struct of_overlay {
+	int id;
+	struct list_head node;
+	int count;
+	struct of_overlay_info *ovinfo_tab;
+	struct of_changeset cset;
+};
+
+static int of_overlay_apply_one(struct of_overlay *ov,
+		struct device_node *target, const struct device_node *overlay);
+
+static int of_overlay_apply_single_property(struct of_overlay *ov,
+		struct device_node *target, struct property *prop)
+{
+	struct property *propn, *tprop;
+
+	/* NOTE: Multiple changes of single properties not supported */
+	tprop = of_find_property(target, prop->name, NULL);
+
+	/* special properties are not meant to be updated (silent NOP) */
+	if (of_prop_cmp(prop->name, "name") == 0 ||
+	    of_prop_cmp(prop->name, "phandle") == 0 ||
+	    of_prop_cmp(prop->name, "linux,phandle") == 0)
+		return 0;
+
+	propn = __of_prop_dup(prop, GFP_KERNEL);
+	if (propn == NULL)
+		return -ENOMEM;
+
+	/* not found? add */
+	if (tprop == NULL)
+		return of_changeset_add_property(&ov->cset, target, propn);
+
+	/* found? update */
+	return of_changeset_update_property(&ov->cset, target, propn);
+}
+
+static int of_overlay_apply_single_device_node(struct of_overlay *ov,
+		struct device_node *target, struct device_node *child)
+{
+	const char *cname;
+	struct device_node *tchild, *grandchild;
+	int ret = 0;
+
+	cname = kbasename(child->full_name);
+	if (cname == NULL)
+		return -ENOMEM;
+
+	/* NOTE: Multiple mods of created nodes not supported */
+	tchild = of_get_child_by_name(target, cname);
+	if (tchild != NULL) {
+		/* apply overlay recursively */
+		ret = of_overlay_apply_one(ov, tchild, child);
+		of_node_put(tchild);
+	} else {
+		/* create empty tree as a target */
+		tchild = __of_node_dup(child, "%s/%s", target->full_name, cname);
+		if (!tchild)
+			return -ENOMEM;
+
+		/* point to parent */
+		tchild->parent = target;
+
+		ret = of_changeset_attach_node(&ov->cset, tchild);
+		if (ret)
+			return ret;
+
+		ret = of_overlay_apply_one(ov, tchild, child);
+		if (ret)
+			return ret;
+
+		/* The properties are already copied, now do the child nodes */
+		for_each_child_of_node(child, grandchild) {
+			ret = of_overlay_apply_single_device_node(ov, tchild, grandchild);
+			if (ret) {
+				pr_err("%s: Failed to apply single node @%s/%s\n",
+					__func__, tchild->full_name,
+					grandchild->name);
+				return ret;
+			}
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Apply a single overlay node recursively.
+ *
+ * Note that the in case of an error the target node is left
+ * in a inconsistent state. Error recovery should be performed
+ * by using the changeset.
+ */
+static int of_overlay_apply_one(struct of_overlay *ov,
+		struct device_node *target, const struct device_node *overlay)
+{
+	struct device_node *child;
+	struct property *prop;
+	int ret;
+
+	for_each_property_of_node(overlay, prop) {
+		ret = of_overlay_apply_single_property(ov, target, prop);
+		if (ret) {
+			pr_err("%s: Failed to apply prop @%s/%s\n",
+				__func__, target->full_name, prop->name);
+			return ret;
+		}
+	}
+
+	for_each_child_of_node(overlay, child) {
+		ret = of_overlay_apply_single_device_node(ov, target, child);
+		if (ret != 0) {
+			pr_err("%s: Failed to apply single node @%s/%s\n",
+					__func__, target->full_name,
+					child->name);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * of_overlay_apply() - Apply @count overlays pointed at by @ovinfo_tab
+ * @ov:		Overlay to apply
+ *
+ * Applies the overlays given, while handling all error conditions
+ * appropriately. Either the operation succeeds, or if it fails the
+ * live tree is reverted to the state before the attempt.
+ * Returns 0, or an error if the overlay attempt failed.
+ */
+static int of_overlay_apply(struct of_overlay *ov)
+{
+	int i, err;
+
+	/* first we apply the overlays atomically */
+	for (i = 0; i < ov->count; i++) {
+		struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i];
+
+		err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay);
+		if (err != 0) {
+			pr_err("%s: overlay failed '%s'\n",
+				__func__, ovinfo->target->full_name);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Find the target node using a number of different strategies
+ * in order of preference
+ *
+ * "target" property containing the phandle of the target
+ * "target-path" property containing the path of the target
+ */
+static struct device_node *find_target_node(struct device_node *info_node)
+{
+	const char *path;
+	u32 val;
+	int ret;
+
+	/* first try to go by using the target as a phandle */
+	ret = of_property_read_u32(info_node, "target", &val);
+	if (ret == 0)
+		return of_find_node_by_phandle(val);
+
+	/* now try to locate by path */
+	ret = of_property_read_string(info_node, "target-path", &path);
+	if (ret == 0)
+		return of_find_node_by_path(path);
+
+	pr_err("%s: Failed to find target for node %p (%s)\n", __func__,
+		info_node, info_node->name);
+
+	return NULL;
+}
+
+/**
+ * of_fill_overlay_info() - Fill an overlay info structure
+ * @ov		Overlay to fill
+ * @info_node:	Device node containing the overlay
+ * @ovinfo:	Pointer to the overlay info structure to fill
+ *
+ * Fills an overlay info structure with the overlay information
+ * from a device node. This device node must have a target property
+ * which contains a phandle of the overlay target node, and an
+ * __overlay__ child node which has the overlay contents.
+ * Both ovinfo->target & ovinfo->overlay have their references taken.
+ *
+ * Returns 0 on success, or a negative error value.
+ */
+static int of_fill_overlay_info(struct of_overlay *ov,
+		struct device_node *info_node, struct of_overlay_info *ovinfo)
+{
+	ovinfo->overlay = of_get_child_by_name(info_node, "__overlay__");
+	if (ovinfo->overlay == NULL)
+		goto err_fail;
+
+	ovinfo->target = find_target_node(info_node);
+	if (ovinfo->target == NULL)
+		goto err_fail;
+
+	return 0;
+
+err_fail:
+	of_node_put(ovinfo->target);
+	of_node_put(ovinfo->overlay);
+
+	memset(ovinfo, 0, sizeof(*ovinfo));
+	return -EINVAL;
+}
+
+/**
+ * of_build_overlay_info() - Build an overlay info array
+ * @ov		Overlay to build
+ * @tree:	Device node containing all the overlays
+ *
+ * Helper function that given a tree containing overlay information,
+ * allocates and builds an overlay info array containing it, ready
+ * for use using of_overlay_apply.
+ *
+ * Returns 0 on success with the @cntp @ovinfop pointers valid,
+ * while on error a negative error value is returned.
+ */
+static int of_build_overlay_info(struct of_overlay *ov,
+		struct device_node *tree)
+{
+	struct device_node *node;
+	struct of_overlay_info *ovinfo;
+	int cnt, err;
+
+	/* worst case; every child is a node */
+	cnt = 0;
+	for_each_child_of_node(tree, node)
+		cnt++;
+
+	ovinfo = kcalloc(cnt, sizeof(*ovinfo), GFP_KERNEL);
+	if (ovinfo == NULL)
+		return -ENOMEM;
+
+	cnt = 0;
+	for_each_child_of_node(tree, node) {
+		memset(&ovinfo[cnt], 0, sizeof(*ovinfo));
+		err = of_fill_overlay_info(ov, node, &ovinfo[cnt]);
+		if (err == 0)
+			cnt++;
+	}
+
+	/* if nothing filled, return error */
+	if (cnt == 0) {
+		kfree(ovinfo);
+		return -ENODEV;
+	}
+
+	ov->count = cnt;
+	ov->ovinfo_tab = ovinfo;
+
+	return 0;
+}
+
+/**
+ * of_free_overlay_info() - Free an overlay info array
+ * @ov		Overlay to free the overlay info from
+ * @ovinfo_tab:	Array of overlay_info's to free
+ *
+ * Releases the memory of a previously allocated ovinfo array
+ * by of_build_overlay_info.
+ * Returns 0, or an error if the arguments are bogus.
+ */
+static int of_free_overlay_info(struct of_overlay *ov)
+{
+	struct of_overlay_info *ovinfo;
+	int i;
+
+	/* do it in reverse */
+	for (i = ov->count - 1; i >= 0; i--) {
+		ovinfo = &ov->ovinfo_tab[i];
+
+		of_node_put(ovinfo->target);
+		of_node_put(ovinfo->overlay);
+	}
+	kfree(ov->ovinfo_tab);
+
+	return 0;
+}
+
+static LIST_HEAD(ov_list);
+static DEFINE_IDR(ov_idr);
+
+/**
+ * of_overlay_create() - Create and apply an overlay
+ * @tree:	Device node containing all the overlays
+ *
+ * Creates and applies an overlay while also keeping track
+ * of the overlay in a list. This list can be used to prevent
+ * illegal overlay removals.
+ *
+ * Returns the id of the created overlay, or an negative error number
+ */
+int of_overlay_create(struct device_node *tree)
+{
+	struct of_overlay *ov;
+	int err, id;
+
+	/* allocate the overlay structure */
+	ov = kzalloc(sizeof(*ov), GFP_KERNEL);
+	if (ov == NULL)
+		return -ENOMEM;
+	ov->id = -1;
+
+	INIT_LIST_HEAD(&ov->node);
+
+	of_changeset_init(&ov->cset);
+
+	mutex_lock(&of_mutex);
+
+	id = idr_alloc(&ov_idr, ov, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		pr_err("%s: idr_alloc() failed for tree@%s\n",
+				__func__, tree->full_name);
+		err = id;
+		goto err_destroy_trans;
+	}
+	ov->id = id;
+
+	/* build the overlay info structures */
+	err = of_build_overlay_info(ov, tree);
+	if (err) {
+		pr_err("%s: of_build_overlay_info() failed for tree@%s\n",
+				__func__, tree->full_name);
+		goto err_free_idr;
+	}
+
+	/* apply the overlay */
+	err = of_overlay_apply(ov);
+	if (err) {
+		pr_err("%s: of_overlay_apply() failed for tree@%s\n",
+				__func__, tree->full_name);
+		goto err_abort_trans;
+	}
+
+	/* apply the changeset */
+	err = of_changeset_apply(&ov->cset);
+	if (err) {
+		pr_err("%s: of_changeset_apply() failed for tree@%s\n",
+				__func__, tree->full_name);
+		goto err_revert_overlay;
+	}
+
+	/* add to the tail of the overlay list */
+	list_add_tail(&ov->node, &ov_list);
+
+	mutex_unlock(&of_mutex);
+
+	return id;
+
+err_revert_overlay:
+err_abort_trans:
+	of_free_overlay_info(ov);
+err_free_idr:
+	idr_remove(&ov_idr, ov->id);
+err_destroy_trans:
+	of_changeset_destroy(&ov->cset);
+	kfree(ov);
+	mutex_unlock(&of_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(of_overlay_create);
+
+/* check whether the given node, lies under the given tree */
+static int overlay_subtree_check(struct device_node *tree,
+		struct device_node *dn)
+{
+	struct device_node *child;
+
+	/* match? */
+	if (tree == dn)
+		return 1;
+
+	for_each_child_of_node(tree, child) {
+		if (overlay_subtree_check(child, dn))
+			return 1;
+	}
+
+	return 0;
+}
+
+/* check whether this overlay is the topmost */
+static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn)
+{
+	struct of_overlay *ovt;
+	struct of_changeset_entry *ce;
+
+	list_for_each_entry_reverse(ovt, &ov_list, node) {
+		/* if we hit ourselves, we're done */
+		if (ovt == ov)
+			break;
+
+		/* check against each subtree affected by this overlay */
+		list_for_each_entry(ce, &ovt->cset.entries, node) {
+			if (overlay_subtree_check(ce->np, dn)) {
+				pr_err("%s: #%d clashes #%d @%s\n",
+					__func__, ov->id, ovt->id,
+					dn->full_name);
+				return 0;
+			}
+		}
+	}
+
+	/* overlay is topmost */
+	return 1;
+}
+
+/*
+ * We can safely remove the overlay only if it's the top-most one.
+ * Newly applied overlays are inserted at the tail of the overlay list,
+ * so a top most overlay is the one that is closest to the tail.
+ *
+ * The topmost check is done by exploiting this property. For each
+ * affected device node in the log list we check if this overlay is
+ * the one closest to the tail. If another overlay has affected this
+ * device node and is closest to the tail, then removal is not permited.
+ */
+static int overlay_removal_is_ok(struct of_overlay *ov)
+{
+	struct of_changeset_entry *ce;
+
+	list_for_each_entry(ce, &ov->cset.entries, node) {
+		if (!overlay_is_topmost(ov, ce->np)) {
+			pr_err("%s: overlay #%d is not topmost\n",
+					__func__, ov->id);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/**
+ * of_overlay_destroy() - Removes an overlay
+ * @id:	Overlay id number returned by a previous call to of_overlay_create
+ *
+ * Removes an overlay if it is permissible.
+ *
+ * Returns 0 on success, or an negative error number
+ */
+int of_overlay_destroy(int id)
+{
+	struct of_overlay *ov;
+	int err;
+
+	mutex_lock(&of_mutex);
+
+	ov = idr_find(&ov_idr, id);
+	if (ov == NULL) {
+		err = -ENODEV;
+		pr_err("%s: Could not find overlay #%d\n",
+				__func__, id);
+		goto out;
+	}
+
+	/* check whether the overlay is safe to remove */
+	if (!overlay_removal_is_ok(ov)) {
+		err = -EBUSY;
+		pr_err("%s: removal check failed for overlay #%d\n",
+				__func__, id);
+		goto out;
+	}
+
+
+	list_del(&ov->node);
+	of_changeset_revert(&ov->cset);
+	of_free_overlay_info(ov);
+	idr_remove(&ov_idr, id);
+	of_changeset_destroy(&ov->cset);
+	kfree(ov);
+
+	err = 0;
+
+out:
+	mutex_unlock(&of_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(of_overlay_destroy);
+
+/**
+ * of_overlay_destroy_all() - Removes all overlays from the system
+ *
+ * Removes all overlays from the system in the correct order.
+ *
+ * Returns 0 on success, or an negative error number
+ */
+int of_overlay_destroy_all(void)
+{
+	struct of_overlay *ov, *ovn;
+
+	mutex_lock(&of_mutex);
+
+	/* the tail of list is guaranteed to be safe to remove */
+	list_for_each_entry_safe_reverse(ov, ovn, &ov_list, node) {
+		list_del(&ov->node);
+		of_changeset_revert(&ov->cset);
+		of_free_overlay_info(ov);
+		idr_remove(&ov_idr, ov->id);
+		kfree(ov);
+	}
+
+	mutex_unlock(&of_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_overlay_destroy_all);
diff --git a/include/linux/of.h b/include/linux/of.h
index fe1dec87fd68..aa01cf5852f8 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -23,6 +23,7 @@
 #include <linux/spinlock.h>
 #include <linux/topology.h>
 #include <linux/notifier.h>
+#include <linux/list.h>
 
 #include <asm/byteorder.h>
 #include <asm/errno.h>
@@ -957,4 +958,34 @@ static inline int of_reconfig_get_state_change(unsigned long action,
 /* CONFIG_OF_RESOLVE api */
 extern int of_resolve_phandles(struct device_node *tree);
 
+/**
+ * Overlay support
+ */
+
+#ifdef CONFIG_OF_OVERLAY
+
+/* ID based overlays; the API for external users */
+int of_overlay_create(struct device_node *tree);
+int of_overlay_destroy(int id);
+int of_overlay_destroy_all(void);
+
+#else
+
+static inline int of_overlay_create(struct device_node *tree)
+{
+	return -ENOTSUPP;
+}
+
+static inline int of_overlay_destroy(int id)
+{
+	return -ENOTSUPP;
+}
+
+static inline int of_overlay_destroy_all(void)
+{
+	return -ENOTSUPP;
+}
+
+#endif
+
 #endif /* _LINUX_OF_H */
-- 
cgit v1.2.3-55-g7522


From 75c28c09af99a0db0ccd8b4395469761aa736543 Mon Sep 17 00:00:00 2001
From: Leif Lindholm
Date: Fri, 28 Nov 2014 11:34:28 +0000
Subject: of: add optional options parameter to of_find_node_by_path()

Update of_find_node_by_path():
1) Rename function to of_find_node_opts_by_path(), adding an optional
   pointer argument. Provide a static inline wrapper version of
   of_find_node_by_path() which calls the new function with NULL as
   the optional argument.
2) Ignore any part of the path beyond and including the ':' separator.
3) Set the new provided pointer argument to the beginning of the string
   following the ':' separator.
4: Add tests.

Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
 drivers/of/base.c     | 20 ++++++++++++++++----
 drivers/of/unittest.c | 30 ++++++++++++++++++++++++++++++
 include/linux/of.h    | 14 +++++++++++++-
 3 files changed, 59 insertions(+), 5 deletions(-)

(limited to 'include/linux/of.h')

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 99bc95e83d09..bdf051d0a7e6 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -714,10 +714,15 @@ static struct device_node *__of_find_node_by_path(struct device_node *parent,
 {
 	struct device_node *child;
 	int len = strchrnul(path, '/') - path;
+	int term;
 
 	if (!len)
 		return NULL;
 
+	term = strchrnul(path, ':') - path;
+	if (term < len)
+		len = term;
+
 	__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))
@@ -730,11 +735,14 @@ static struct device_node *__of_find_node_by_path(struct device_node *parent,
 }
 
 /**
- *	of_find_node_by_path - Find a node matching a full OF path
+ *	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
@@ -744,11 +752,15 @@ static struct device_node *__of_find_node_by_path(struct device_node *parent,
  *	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 *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);
@@ -756,7 +768,7 @@ struct device_node *of_find_node_by_path(const char *path)
 	/* The path could begin with an alias */
 	if (*path != '/') {
 		char *p = strchrnul(path, '/');
-		int len = p - path;
+		int len = separator ? separator - path : p - path;
 
 		/* of_aliases must not be NULL */
 		if (!of_aliases)
@@ -785,7 +797,7 @@ struct device_node *of_find_node_by_path(const char *path)
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return np;
 }
-EXPORT_SYMBOL(of_find_node_by_path);
+EXPORT_SYMBOL(of_find_node_opts_by_path);
 
 /**
  *	of_find_node_by_name - Find a node by its "name" property
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 7a7ae07d592f..1807a0458648 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -47,6 +47,7 @@ static bool selftest_live_tree;
 static void __init of_selftest_find_node_by_name(void)
 {
 	struct device_node *np;
+	const char *options;
 
 	np = of_find_node_by_path("/testcase-data");
 	selftest(np && !strcmp("/testcase-data", np->full_name),
@@ -87,6 +88,35 @@ static void __init of_selftest_find_node_by_name(void)
 	np = of_find_node_by_path("testcase-alias/missing-path");
 	selftest(!np, "non-existent alias with relative path returned node %s\n", np->full_name);
 	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:testoption", &options);
+	selftest(np && !strcmp("testoption", options),
+		 "option path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:testoption", NULL);
+	selftest(np, "NULL option path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:testaliasoption",
+				       &options);
+	selftest(np && !strcmp("testaliasoption", options),
+		 "option alias path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:testaliasoption", NULL);
+	selftest(np, "NULL option alias path test failed\n");
+	of_node_put(np);
+
+	options = "testoption";
+	np = of_find_node_opts_by_path("testcase-alias", &options);
+	selftest(np && !options, "option clearing test failed\n");
+	of_node_put(np);
+
+	options = "testoption";
+	np = of_find_node_opts_by_path("/", &options);
+	selftest(np && !options, "option clearing root node test failed\n");
+	of_node_put(np);
 }
 
 static void __init of_selftest_dynamic(void)
diff --git a/include/linux/of.h b/include/linux/of.h
index aa01cf5852f8..8b021db3e16e 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -236,7 +236,13 @@ extern struct device_node *of_find_matching_node_and_match(
 	const struct of_device_id *matches,
 	const struct of_device_id **match);
 
-extern struct device_node *of_find_node_by_path(const char *path);
+extern struct device_node *of_find_node_opts_by_path(const char *path,
+	const char **opts);
+static inline struct device_node *of_find_node_by_path(const char *path)
+{
+	return of_find_node_opts_by_path(path, NULL);
+}
+
 extern struct device_node *of_find_node_by_phandle(phandle handle);
 extern struct device_node *of_get_parent(const struct device_node *node);
 extern struct device_node *of_get_next_parent(struct device_node *node);
@@ -383,6 +389,12 @@ static inline struct device_node *of_find_node_by_path(const char *path)
 	return NULL;
 }
 
+static inline struct device_node *of_find_node_opts_by_path(const char *path,
+	const char **opts)
+{
+	return NULL;
+}
+
 static inline struct device_node *of_get_parent(const struct device_node *node)
 {
 	return NULL;
-- 
cgit v1.2.3-55-g7522


From 70161ff336674ecfd20614a9c0c61cb17a6e9e83 Mon Sep 17 00:00:00 2001
From: Grant Likely
Date: Fri, 28 Nov 2014 16:03:33 +0000
Subject: of: Drop ->next pointer from struct device_node

The ->next pointer in struct device_node is a hanger-on from when it was
used to iterate over the whole tree by a particular device_type property
value. Those days are long over, but the fdt unflattening code still
uses it to put nodes in the unflattened tree into the same order as node
in the flat tree. By reworking the unflattening code to reverse the list
after unflattening all the children of a node, the pointer can be
dropped which gives a small amount of memory savings.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Frank Rowand <frank.rowand@sonymobile.com>
Cc: Gaurav Minocha <gaurav.minocha.os@gmail.com>
---
 drivers/of/fdt.c   | 24 ++++++++++++++++++------
 include/linux/of.h |  1 -
 2 files changed, 18 insertions(+), 7 deletions(-)

(limited to 'include/linux/of.h')

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 7f6ee31d5650..a41f9fdb1aa0 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -226,12 +226,8 @@ static void * unflatten_dt_node(void *blob,
 		prev_pp = &np->properties;
 		if (dad != NULL) {
 			np->parent = dad;
-			/* we temporarily use the next field as `last_child'*/
-			if (dad->next == NULL)
-				dad->child = np;
-			else
-				dad->next->sibling = np;
-			dad->next = np;
+			np->sibling = dad->child;
+			dad->child = np;
 		}
 	}
 	/* process properties */
@@ -329,6 +325,22 @@ static void * unflatten_dt_node(void *blob,
 
 	if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
 		pr_err("unflatten: error %d processing FDT\n", *poffset);
+
+	/*
+	 * Reverse the child list. Some drivers assumes node order matches .dts
+	 * node order
+	 */
+	if (!dryrun && np->child) {
+		struct device_node *child = np->child;
+		np->child = NULL;
+		while (child) {
+			struct device_node *next = child->sibling;
+			child->sibling = np->child;
+			np->child = child;
+			child = next;
+		}
+	}
+
 	if (nodepp)
 		*nodepp = np;
 
diff --git a/include/linux/of.h b/include/linux/of.h
index 8b021db3e16e..3f0f0ffbd5e5 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -56,7 +56,6 @@ struct device_node {
 	struct	device_node *parent;
 	struct	device_node *child;
 	struct	device_node *sibling;
-	struct	device_node *next;	/* next device of same type */
 	struct	kobject kobj;
 	unsigned long _flags;
 	void	*data;
-- 
cgit v1.2.3-55-g7522