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>

6 files changed, 25 insertions, 30 deletions

diff --git a/arch/powerpc/platforms/85xx/p1022_ds.c b/arch/powerpc/platforms/85xx/p1022_ds.c
index 74e310b4b460..31d18b964f94 100644
--- a/arch/powerpc/platforms/85xx/p1022_ds.c
+++ b/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. */
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 029a562af373..dd30b12edfe4 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/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;
         }
 
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 7b3bf76ef834..39f71fba9b38 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/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;
 
@@ -443,6 +443,9 @@ 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;
@@ -450,18 +453,11 @@ static int do_update_property(char *buf, size_t bufsize)
         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;
                 }
         }
diff --git a/drivers/of/base.c b/drivers/of/base.c
index eada3f4ef801..bc86ea2af668 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1073,7 +1073,8 @@ 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.
@@ -1081,13 +1082,19 @@ int prom_remove_property(struct device_node *np, struct property *prop)
  * 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) {
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
index 927cbd115e53..df7dd08d4391 100644
--- a/fs/proc/proc_devtree.c
+++ b/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;
diff --git a/include/linux/of.h b/include/linux/of.h
index 2ec1083af7ff..b27c87191df2 100644
--- a/include/linux/of.h
+++ b/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 */