[POWERPC] Add an optional device_node pointer to the irq_host

The majority of irq_host implementations (3 out of 4) are associated
with a device_node, and need to stash it somewhere. Rather than having
it somewhere different for each host, add an optional device_node pointer
to the irq_host structure.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/sysdev/tsi108_pci.c b/arch/powerpc/sysdev/tsi108_pci.c
index cf0bfbd..b41492a 100644
--- a/arch/powerpc/sysdev/tsi108_pci.c
+++ b/arch/powerpc/sysdev/tsi108_pci.c
@@ -52,7 +52,6 @@
 u32 tsi108_pci_cfg_base;
 static u32 tsi108_pci_cfg_phys;
 u32 tsi108_csr_vir_base;
-static struct device_node *pci_irq_node;
 static struct irq_host *pci_irq_host;
 
 extern u32 get_vir_csrbase(void);
@@ -407,7 +406,7 @@
 
 static int pci_irq_host_match(struct irq_host *h, struct device_node *node)
 {
-	return pci_irq_node == node;
+	return h->of_node == node;
 }
 
 static struct irq_host_ops pci_irq_host_ops = {
@@ -433,10 +432,11 @@
 {
 	DBG("Tsi108_pci_int_init: initializing PCI interrupts\n");
 
-	pci_irq_node = of_node_get(node);
-	pci_irq_host = irq_alloc_host(IRQ_HOST_MAP_LEGACY, 0, &pci_irq_host_ops, 0);
+	pci_irq_host = irq_alloc_host(of_node_get(node), IRQ_HOST_MAP_LEGACY,
+				      0, &pci_irq_host_ops, 0);
 	if (pci_irq_host == NULL) {
 		printk(KERN_ERR "pci_irq_host: failed to allocate irq host !\n");
+		of_node_put(node);
 		return;
 	}