powerpc/pseries: extract of_helpers module

Extract a new module to share the code between other modules.

There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/pseries/Makefile

@@ -2,6 +2,7 @@ ccflags-$(CONFIG_PPC64)			:= $(NO_MINIMAL_TOC)
 ccflags-$(CONFIG_PPC_PSERIES_DEBUG)	+= -DDEBUG
 
 obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
+			   of_helpers.o \
 			   setup.o iommu.o event_sources.o ras.o \
 			   firmware.o power.o dlpar.o mobility.o rng.o
 obj-$(CONFIG_SMP)	+= smp.o

arch/powerpc/platforms/pseries/of_helpers.c

+#include <linux/string.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "of_helpers.h"
+
+/**
+ * pseries_of_derive_parent - basically like dirname(1)
+ * @path:  the full_name of a node to be added to the tree
+ *
+ * Returns the node which should be the parent of the node
+ * described by path.  E.g., for path = "/foo/bar", returns
+ * the node with full_name = "/foo".
+ */
+struct device_node *pseries_of_derive_parent(const char *path)
+{
+	struct device_node *parent = NULL;
+	char *parent_path = "/";
+	size_t parent_path_len = strrchr(path, '/') - path + 1;
+
+	/* reject if path is "/" */
+	if (!strcmp(path, "/"))
+		return ERR_PTR(-EINVAL);
+
+	if (strrchr(path, '/') != path) {
+		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
+		if (!parent_path)
+			return ERR_PTR(-ENOMEM);
+		strlcpy(parent_path, path, parent_path_len);
+	}
+	parent = of_find_node_by_path(parent_path);
+	if (!parent)
+		return ERR_PTR(-EINVAL);
+	if (strcmp(parent_path, "/"))
+		kfree(parent_path);
+	return parent;
+}

arch/powerpc/platforms/pseries/of_helpers.h

+#ifndef _PSERIES_OF_HELPERS_H
+#define _PSERIES_OF_HELPERS_H
+
+#include <linux/of.h>
+
+struct device_node *pseries_of_derive_parent(const char *path);
+
+#endif /* _PSERIES_OF_HELPERS_H */

arch/powerpc/platforms/pseries/reconfig.c

@@ -22,37 +22,7 @@
 #include <asm/uaccess.h>
 #include <asm/mmu.h>
 
-/**
- *	derive_parent - basically like dirname(1)
- *	@path:  the full_name of a node to be added to the tree
- *
- *	Returns the node which should be the parent of the node
- *	described by path.  E.g., for path = "/foo/bar", returns
- *	the node with full_name = "/foo".
- */
-static struct device_node *derive_parent(const char *path)
-{
-	struct device_node *parent = NULL;
-	char *parent_path = "/";
-	size_t parent_path_len = strrchr(path, '/') - path + 1;
-
-	/* reject if path is "/" */
-	if (!strcmp(path, "/"))
-		return ERR_PTR(-EINVAL);
-
-	if (strrchr(path, '/') != path) {
-		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
-		if (!parent_path)
-			return ERR_PTR(-ENOMEM);
-		strlcpy(parent_path, path, parent_path_len);
-	}
-	parent = of_find_node_by_path(parent_path);
-	if (!parent)
-		return ERR_PTR(-EINVAL);
-	if (strcmp(parent_path, "/"))
-		kfree(parent_path);
-	return parent;
-}
+#include "of_helpers.h"
 
 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 {
@@ -71,7 +41,7 @@ static int pSeries_reconfig_add_node(const char *path, struct property *proplist
 	of_node_set_flag(np, OF_DYNAMIC);
 	of_node_init(np);
 
-	np->parent = derive_parent(path);
+	np->parent = pseries_of_derive_parent(path);
 	if (IS_ERR(np->parent)) {
 		err = PTR_ERR(np->parent);
 		goto out_err;