powerpc/mpic: Search for open-pic device-tree node if NULL

Almost all PowerPC platforms use a standard "open-pic" device node so
the mpic_alloc() function now accepts NULL for the device-node.  This
will cause it to perform a default search with of_find_matching_node().

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 30 insertions, 4 deletions

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index ef721c30f479..bb72a6266480 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1143,8 +1143,24 @@ struct mpic * __init mpic_alloc(struct device_node *node,
         const char *vers;
         const u32 *psrc;
 
-        /* This code assumes that a non-NULL device node is passed in */
-        BUG_ON(!node);
+        /* Default MPIC search parameters */
+        static const struct of_device_id __initconst mpic_device_id[] = {
+                { .type       = "open-pic", },
+                { .compatible = "open-pic", },
+                {},
+        };
+
+        /*
+         * If we were not passed a device-tree node, then perform the default
+         * search for standardized a standardized OpenPIC.
+         */
+        if (node) {
+                node = of_node_get(node);
+        } else {
+                node = of_find_matching_node(NULL, mpic_device_id);
+                if (!node)
+                        return NULL;
+        }
 
         /* Pick the physical address from the device tree if unspecified */
         if (!phys_addr) {
@@ -1154,14 +1170,14 @@ struct mpic * __init mpic_alloc(struct device_node *node,
                 } else {
                         struct resource r;
                         if (of_address_to_resource(node, 0, &r))
-                                return NULL;
+                                goto err_of_node_put;
                         phys_addr = r.start;
                 }
         }
 
         mpic = kzalloc(sizeof(struct mpic), GFP_KERNEL);
         if (mpic == NULL)
-                return NULL;
+                goto err_of_node_put;
 
         mpic->name = name;
         mpic->paddr = phys_addr;
@@ -1325,6 +1341,11 @@ struct mpic * __init mpic_alloc(struct device_node *node,
                                        isu_size ? isu_size : mpic->num_sources,
                                        &mpic_host_ops,
                                        flags & MPIC_LARGE_VECTORS ? 2048 : 256);
+
+        /*
+         * FIXME: The code leaks the MPIC object and mappings here; this
+         * is very unlikely to fail but it ought to be fixed anyways.
+         */
         if (mpic->irqhost == NULL)
                 return NULL;
 
@@ -1359,7 +1380,12 @@ struct mpic * __init mpic_alloc(struct device_node *node,
                 irq_set_default_host(mpic->irqhost);
         }
 
+        of_node_put(node);
         return mpic;
+
+err_of_node_put:
+        of_node_put(node);
+        return NULL;
 }
 
 void __init mpic_assign_isu(struct mpic *mpic, unsigned int isu_num,