of: Fix locking vs. interrupts

The OF code uses irqsafe locks everywhere except in a handful of functions
for no obvious reasons. Since the conversion from the old rwlocks, this
now triggers lockdep warnings when used at interrupt time. At least one
driver (ibmvscsi) seems to be doing that from softirq context.

This converts the few non-irqsafe locks into irqsafe ones, making them
consistent with the rest of the code.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index f53b992f060a..a6f584a7f4a1 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -192,14 +192,15 @@ EXPORT_SYMBOL(of_find_property);
 struct device_node *of_find_all_nodes(struct device_node *prev)
 {
         struct device_node *np;
+        unsigned long flags;
 
-        raw_spin_lock(&devtree_lock);
+        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;
         of_node_put(prev);
-        raw_spin_unlock(&devtree_lock);
+        raw_spin_unlock_irqrestore(&devtree_lock, flags);
         return np;
 }
 EXPORT_SYMBOL(of_find_all_nodes);
@@ -421,8 +422,9 @@ struct device_node *of_get_next_available_child(const struct device_node *node,
         struct device_node *prev)
 {
         struct device_node *next;
+        unsigned long flags;
 
-        raw_spin_lock(&devtree_lock);
+        raw_spin_lock_irqsave(&devtree_lock, flags);
         next = prev ? prev->sibling : node->child;
         for (; next; next = next->sibling) {
                 if (!__of_device_is_available(next))
@@ -431,7 +433,7 @@ struct device_node *of_get_next_available_child(const struct device_node *node,
                         break;
         }
         of_node_put(prev);
-        raw_spin_unlock(&devtree_lock);
+        raw_spin_unlock_irqrestore(&devtree_lock, flags);
         return next;
 }
 EXPORT_SYMBOL(of_get_next_available_child);
@@ -735,13 +737,14 @@ EXPORT_SYMBOL_GPL(of_modalias_node);
 struct device_node *of_find_node_by_phandle(phandle handle)
 {
         struct device_node *np;
+        unsigned long flags;
 
-        raw_spin_lock(&devtree_lock);
+        raw_spin_lock_irqsave(&devtree_lock, flags);
         for (np = of_allnodes; np; np = np->allnext)
                 if (np->phandle == handle)
                         break;
         of_node_get(np);
-        raw_spin_unlock(&devtree_lock);
+        raw_spin_unlock_irqrestore(&devtree_lock, flags);
         return np;
 }
 EXPORT_SYMBOL(of_find_node_by_phandle);