powerpc/mpic: Assume a device-node was passed in mpic_alloc()

All of the existing callers of mpic_alloc() pass in a non-NULL
device-node pointer, so the checks for a NULL device-node may be
removed.
Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/sysdev/mpic.c

@@ -1137,19 +1137,17 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 				unsigned int irq_count,
 				const char *name)
 {
+	int i, psize, intvec_top;
 	struct mpic *mpic;
 	u32 greg_feature;
 	const char *vers;
-	int		i;
-	int		intvec_top;
+	const u32 *psrc;
 
-	/*
-	 * If no phyiscal address was specified then all of the phyiscal
-	 * addressing parameters must come from the device-tree.
-	 */
-	if (!phys_addr) {
+	/* This code assumes that a non-NULL device node is passed in */
 	BUG_ON(!node);
 
+	/* Pick the physical address from the device tree if unspecified */
+	if (!phys_addr) {
 		/* Check if it is DCR-based */
 		if (of_get_property(node, "dcr-reg", NULL)) {
 			flags |= MPIC_USES_DCR;
@@ -1211,30 +1209,24 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 	mpic->spurious_vec  = intvec_top;
 
 	/* Check for "big-endian" in device-tree */
-	if (node && of_get_property(node, "big-endian", NULL) != NULL)
+	if (of_get_property(node, "big-endian", NULL) != NULL)
 		mpic->flags |= MPIC_BIG_ENDIAN;
-	if (node && of_device_is_compatible(node, "fsl,mpic"))
+	if (of_device_is_compatible(node, "fsl,mpic"))
 		mpic->flags |= MPIC_FSL;
 
 	/* Look for protected sources */
-	if (node) {
-		int psize;
-		unsigned int bits, mapsize;
-		const u32 *psrc =
-			of_get_property(node, "protected-sources", &psize);
+	psrc = of_get_property(node, "protected-sources", &psize);
 	if (psrc) {
-			psize /= 4;
-			bits = intvec_top + 1;
-			mapsize = BITS_TO_LONGS(bits) * sizeof(unsigned long);
-			mpic->protected = kzalloc(mapsize, GFP_KERNEL);
+		/* Allocate a bitmap with one bit per interrupt */
+		unsigned int mapsize = BITS_TO_LONGS(intvec_top + 1);
+		mpic->protected = kzalloc(mapsize*sizeof(long), GFP_KERNEL);
 		BUG_ON(mpic->protected == NULL);
-			for (i = 0; i < psize; i++) {
+		for (i = 0; i < psize/sizeof(u32); i++) {
 			if (psrc[i] > intvec_top)
 				continue;
 			__set_bit(psrc[i], mpic->protected);
 		}
 	}
-	}
 
 #ifdef CONFIG_MPIC_WEIRD
 	mpic->hw_set = mpic_infos[MPIC_GET_REGSET(flags)];