of: Improve prom_update_property() function

prom_update_property() currently fails if the property doesn't
actually exist yet which isn't what we want. Change to add-or-update
instead of update-only, then we can remove a lot duplicated lines.

Suggested-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/85xx/p1022_ds.c

@@ -348,13 +348,7 @@ void __init p1022_ds_pic_init(void)
  */
 static void __init disable_one_node(struct device_node *np, struct property *new)
 {
-	struct property *old;
-
-	old = of_find_property(np, new->name, NULL);
-	if (old)
-		prom_update_property(np, new, old);
-	else
-		prom_add_property(np, new);
+	prom_update_property(np, new);
 }
 
 /* TRUE if there is a "video=fslfb" command-line parameter. */

arch/powerpc/platforms/pseries/mobility.c

@@ -67,7 +67,6 @@ static int update_dt_property(struct device_node *dn, struct property **prop,
 			      const char *name, u32 vd, char *value)
 {
 	struct property *new_prop = *prop;
-	struct property *old_prop;
 	int more = 0;
 
 	/* A negative 'vd' value indicates that only part of the new property
@@ -117,12 +116,7 @@ static int update_dt_property(struct device_node *dn, struct property **prop,
 	}
 
 	if (!more) {
-		old_prop = of_find_property(dn, new_prop->name, NULL);
-		if (old_prop)
-			prom_update_property(dn, new_prop, old_prop);
-		else
-			prom_add_property(dn, new_prop);
-
+		prom_update_property(dn, new_prop);
 		new_prop = NULL;
 	}
 

arch/powerpc/platforms/pseries/reconfig.c

@@ -432,7 +432,7 @@ static int do_update_property(char *buf, size_t bufsize)
 	unsigned char *value;
 	char *name, *end, *next_prop;
 	int rc, length;
-	struct property *newprop, *oldprop;
+	struct property *newprop;
 	buf = parse_node(buf, bufsize, &np);
 	end = buf + bufsize;
 
@@ -443,25 +443,21 @@ static int do_update_property(char *buf, size_t bufsize)
 	if (!next_prop)
 		return -EINVAL;
 
+	if (!strlen(name))
+		return -ENODEV;
+
 	newprop = new_property(name, length, value, NULL);
 	if (!newprop)
 		return -ENOMEM;
 
 	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
 		slb_set_size(*(int *)value);
 
-	oldprop = of_find_property(np, name,NULL);
-	if (!oldprop) {
-		if (strlen(name))
-			return prom_add_property(np, newprop);
-		return -ENODEV;
-	}
-
 	upd_value.node = np;
 	upd_value.property = newprop;
 	pSeries_reconfig_notify(PSERIES_UPDATE_PROPERTY, &upd_value);
 
-	rc = prom_update_property(np, newprop, oldprop);
+	rc = prom_update_property(np, newprop);
 	if (rc)
 		return rc;
 
@@ -486,7 +482,7 @@ static int do_update_property(char *buf, size_t bufsize)
 
 		rc = pSeries_reconfig_notify(action, value);
 		if (rc) {
-			prom_update_property(np, oldprop, newprop);
+			prom_update_property(np, newprop);
 			return rc;
 		}
 	}

drivers/of/base.c

@@ -1073,21 +1073,28 @@ int prom_remove_property(struct device_node *np, struct property *prop)
 }
 
 /*
- * prom_update_property - Update a property in a node.
+ * prom_update_property - Update a property in a node, if the property does
+ * not exist, add it.
  *
  * Note that we don't actually remove it, since we have given out
  * who-knows-how-many pointers to the data using get-property.
  * Instead we just move the property to the "dead properties" list,
  * and add the new property to the property list
  */
 int prom_update_property(struct device_node *np,
-			 struct property *newprop,
-			 struct property *oldprop)
+			 struct property *newprop)
 {
-	struct property **next;
+	struct property **next, *oldprop;
 	unsigned long flags;
 	int found = 0;
 
+	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);
 	next = &np->properties;
 	while (*next) {

fs/proc/proc_devtree.c

@@ -101,6 +101,11 @@ void proc_device_tree_update_prop(struct proc_dir_entry *pde,
 {
 	struct proc_dir_entry *ent;
 
+	if (!oldprop) {
+		proc_device_tree_add_prop(pde, newprop);
+		return;
+	}
+
 	for (ent = pde->subdir; ent != NULL; ent = ent->next)
 		if (ent->data == oldprop)
 			break;

include/linux/of.h

@@ -260,8 +260,7 @@ extern int of_machine_is_compatible(const char *compat);
 extern int prom_add_property(struct device_node* np, struct property* prop);
 extern int prom_remove_property(struct device_node *np, struct property *prop);
 extern int prom_update_property(struct device_node *np,
-				struct property *newprop,
-				struct property *oldprop);
+				struct property *newprop);
 
 #if defined(CONFIG_OF_DYNAMIC)
 /* For updating the device tree at runtime */