diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
index f081c60..eb39bc9 100644
--- a/arch/ia64/kernel/mca_drv.c
+++ b/arch/ia64/kernel/mca_drv.c
@@ -88,7 +88,7 @@
 	if (!ia64_phys_addr_valid(paddr))
 		return ISOLATE_NONE;
 
-	if (!pfn_valid(paddr))
+	if (!pfn_valid(paddr >> PAGE_SHIFT))
 		return ISOLATE_NONE;
 
 	/* convert physical address to physical page number */
@@ -108,6 +108,7 @@
 		return ISOLATE_NG;
 
 	/* add attribute 'Reserved' and register the page */
+	get_page(p);
 	SetPageReserved(p);
 	page_isolate[num_page_isolate++] = p;
 
diff --git a/arch/ia64/sn/pci/pcibr/pcibr_provider.c b/arch/ia64/sn/pci/pcibr/pcibr_provider.c
index 7b03b80..1f500c8 100644
--- a/arch/ia64/sn/pci/pcibr/pcibr_provider.c
+++ b/arch/ia64/sn/pci/pcibr/pcibr_provider.c
@@ -212,13 +212,13 @@
 		    pdi_pcibus_info;
 
 		/* Disable the device's IRQ   */
-		pcireg_intr_enable_bit_clr(pcibus_info, bit);
+		pcireg_intr_enable_bit_clr(pcibus_info, (1 << bit));
 
 		/* Change the device's IRQ    */
 		pcireg_intr_addr_addr_set(pcibus_info, bit, xtalk_addr);
 
 		/* Re-enable the device's IRQ */
-		pcireg_intr_enable_bit_set(pcibus_info, bit);
+		pcireg_intr_enable_bit_set(pcibus_info, (1 << bit));
 
 		pcibr_force_interrupt(sn_irq_info);
 	}
diff --git a/arch/ia64/sn/pci/pcibr/pcibr_reg.c b/arch/ia64/sn/pci/pcibr/pcibr_reg.c
index 4f718c3..5d53409 100644
--- a/arch/ia64/sn/pci/pcibr/pcibr_reg.c
+++ b/arch/ia64/sn/pci/pcibr/pcibr_reg.c
@@ -131,7 +131,7 @@
 			__sn_clrq_relaxed(&ptr->tio.cp_int_enable, bits);
 			break;
 		case PCIBR_BRIDGETYPE_PIC:
-			__sn_clrq_relaxed(&ptr->pic.p_int_enable, ~bits);
+			__sn_clrq_relaxed(&ptr->pic.p_int_enable, bits);
 			break;
 		default:
 			panic