powerpc/pseries: Make dlpar_configure_connector parent node aware

Currently the device nodes created in the device subtree returned by a call to
dlpar_configure_connector are all named in the root node. This is because the
the node name in the work area returned by ibm,configure-connector rtas call
only contains the node name and not the entire node path. Passing the parent
node where the new subtree will be created to dlpar_configure_connector allows
the correct node path to be prefixed in the full_name field.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Acked-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/pseries/dlpar.c

@@ -63,21 +63,24 @@ static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
 	return prop;
 }
 
-static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa)
+static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa,
+					       const char *path)
 {
 	struct device_node *dn;
 	char *name;
 
+	/* If parent node path is "/" advance path to NULL terminator to
+	 * prevent double leading slashs in full_name.
+	 */
+	if (!path[1])
+		path++;
+
 	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
 	if (!dn)
 		return NULL;
 
-	/* The configure connector reported name does not contain a
-	 * preceding '/', so we allocate a buffer large enough to
-	 * prepend this to the full_name.
-	 */
 	name = (char *)ccwa + ccwa->name_offset;
-	dn->full_name = kasprintf(GFP_KERNEL, "/%s", name);
+	dn->full_name = kasprintf(GFP_KERNEL, "%s/%s", path, name);
 	if (!dn->full_name) {
 		kfree(dn);
 		return NULL;
@@ -123,7 +126,8 @@ void dlpar_free_cc_nodes(struct device_node *dn)
 #define CALL_AGAIN	-2
 #define ERR_CFG_USE     -9003
 
-struct device_node *dlpar_configure_connector(u32 drc_index)
+struct device_node *dlpar_configure_connector(u32 drc_index,
+					      struct device_node *parent)
 {
 	struct device_node *dn;
 	struct device_node *first_dn = NULL;
@@ -132,6 +136,7 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 	struct property *last_property = NULL;
 	struct cc_workarea *ccwa;
 	char *data_buf;
+	const char *parent_path = parent->full_name;
 	int cc_token;
 	int rc = -1;
 
@@ -165,7 +170,7 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 			break;
 
 		case NEXT_SIBLING:
-			dn = dlpar_parse_cc_node(ccwa);
+			dn = dlpar_parse_cc_node(ccwa, parent_path);
 			if (!dn)
 				goto cc_error;
 
@@ -175,13 +180,17 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 			break;
 
 		case NEXT_CHILD:
-			dn = dlpar_parse_cc_node(ccwa);
+			if (first_dn)
+				parent_path = last_dn->full_name;
+
+			dn = dlpar_parse_cc_node(ccwa, parent_path);
 			if (!dn)
 				goto cc_error;
 
-			if (!first_dn)
+			if (!first_dn) {
+				dn->parent = parent;
 				first_dn = dn;
-			else {
+			} else {
 				dn->parent = last_dn;
 				if (last_dn)
 					last_dn->child = dn;
@@ -205,6 +214,7 @@ struct device_node *dlpar_configure_connector(u32 drc_index)
 
 		case PREV_PARENT:
 			last_dn = last_dn->parent;
+			parent_path = last_dn->parent->full_name;
 			break;
 
 		case CALL_AGAIN:
@@ -383,9 +393,8 @@ out:
 
 static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 {
-	struct device_node *dn;
+	struct device_node *dn, *parent;
 	unsigned long drc_index;
-	char *cpu_name;
 	int rc;
 
 	cpu_hotplug_driver_lock();
@@ -395,25 +404,19 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 		goto out;
 	}
 
-	dn = dlpar_configure_connector(drc_index);
-	if (!dn) {
-		rc = -EINVAL;
+	parent = of_find_node_by_path("/cpus");
+	if (!parent) {
+		rc = -ENODEV;
 		goto out;
 	}
 
-	/* configure-connector reports cpus as living in the base
-	 * directory of the device tree.  CPUs actually live in the
-	 * cpus directory so we need to fixup the full_name.
-	 */
-	cpu_name = kasprintf(GFP_KERNEL, "/cpus%s", dn->full_name);
-	if (!cpu_name) {
-		dlpar_free_cc_nodes(dn);
-		rc = -ENOMEM;
+	dn = dlpar_configure_connector(drc_index, parent);
+	if (!dn) {
+		rc = -EINVAL;
 		goto out;
 	}
 
-	kfree(dn->full_name);
-	dn->full_name = cpu_name;
+	of_node_put(parent);
 
 	rc = dlpar_acquire_drc(drc_index);
 	if (rc) {

arch/powerpc/platforms/pseries/mobility.c

@@ -216,17 +216,14 @@ static int add_dt_node(u32 parent_phandle, u32 drc_index)
 	struct device_node *parent_dn;
 	int rc;
 
-	dn = dlpar_configure_connector(drc_index);
-	if (!dn)
+	parent_dn = of_find_node_by_phandle(parent_phandle);
+	if (!parent_dn)
 		return -ENOENT;
 
-	parent_dn = of_find_node_by_phandle(parent_phandle);
-	if (!parent_dn) {
-		dlpar_free_cc_nodes(dn);
+	dn = dlpar_configure_connector(drc_index, parent_dn);
+	if (!dn)
 		return -ENOENT;
-	}
 
-	dn->parent = parent_dn;
 	rc = dlpar_attach_node(dn);
 	if (rc)
 		dlpar_free_cc_nodes(dn);

arch/powerpc/platforms/pseries/pseries.h

@@ -56,7 +56,7 @@ extern void hvc_vio_init_early(void);
 /* Dynamic logical Partitioning/Mobility */
 extern void dlpar_free_cc_nodes(struct device_node *);
 extern void dlpar_free_cc_property(struct property *);
-extern struct device_node *dlpar_configure_connector(u32);
+extern struct device_node *dlpar_configure_connector(u32, struct device_node *);
 extern int dlpar_attach_node(struct device_node *);
 extern int dlpar_detach_node(struct device_node *);