3 files changed, 45 insertions, 7 deletions

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 6e595e5a3977..75b0d3cb7676 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -24,6 +24,11 @@
 #include <linux/of_irq.h>
 #include <linux/string.h>
 
+/* For archs that don't support NO_IRQ (such as x86), provide a dummy value */
+#ifndef NO_IRQ
+#define NO_IRQ 0
+#endif
+
 /**
  * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
  * @device: Device node of the device whose interrupt is to be mapped
@@ -347,3 +352,37 @@ int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
         return irq;
 }
 EXPORT_SYMBOL_GPL(of_irq_to_resource);
+
+/**
+ * of_irq_count - Count the number of IRQs a node uses
+ * @dev: pointer to device tree node
+ */
+int of_irq_count(struct device_node *dev)
+{
+        int nr = 0;
+
+        while (of_irq_to_resource(dev, nr, NULL) != NO_IRQ)
+                nr++;
+
+        return nr;
+}
+
+/**
+ * of_irq_to_resource_table - Fill in resource table with node's IRQ info
+ * @dev: pointer to device tree node
+ * @res: array of resources to fill in
+ * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
+ *
+ * Returns the size of the filled in table (up to @nr_irqs).
+ */
+int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
+                int nr_irqs)
+{
+        int i;
+
+        for (i = 0; i < nr_irqs; i++, res++)
+                if (of_irq_to_resource(dev, i, res) == NO_IRQ)
+                        break;
+
+        return i;
+}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index bb72223c22ae..30726c8b0693 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -584,14 +584,13 @@ struct platform_device *of_device_alloc(struct device_node *np,
                                   struct device *parent)
 {
         struct platform_device *dev;
-        int rc, i, num_reg = 0, num_irq = 0;
+        int rc, i, num_reg = 0, num_irq;
         struct resource *res, temp_res;
 
         /* First count how many resources are needed */
         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
                 num_reg++;
-        while (of_irq_to_resource(np, num_irq, &temp_res) != NO_IRQ)
-                num_irq++;
+        num_irq = of_irq_count(np);
 
         /* Allocate memory for both the struct device and the resource table */
         dev = kzalloc(sizeof(*dev) + (sizeof(*res) * (num_reg + num_irq)),
@@ -608,10 +607,7 @@ struct platform_device *of_device_alloc(struct device_node *np,
                         rc = of_address_to_resource(np, i, res);
                         WARN_ON(rc);
                 }
-                for (i = 0; i < num_irq; i++, res++) {
-                        rc = of_irq_to_resource(np, i, res);
-                        WARN_ON(rc == NO_IRQ);
-                }
+                WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
         }
 
         dev->dev.of_node = of_node_get(np);
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 5929781c104d..090cbaa4bd36 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -64,6 +64,9 @@ extern unsigned int irq_create_of_mapping(struct device_node *controller,
                                           unsigned int intsize);
 extern int of_irq_to_resource(struct device_node *dev, int index,
                               struct resource *r);
+extern int of_irq_count(struct device_node *dev);
+extern int of_irq_to_resource_table(struct device_node *dev,
+                struct resource *res, int nr_irqs);
 
 #endif /* CONFIG_OF_IRQ */
 #endif /* CONFIG_OF */