diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 2f3f30efffed67e266663337e165f3d3e111dfc6..bea11df0a79bce440bebda89229f69510d4ab214 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -50,6 +50,9 @@ static DEFINE_SPINLOCK(hose_spinlock);
 /* XXX kill that some day ... */
 static int global_phb_number;		/* Global phb counter */
 
+/* ISA Memory physical address */
+resource_size_t isa_mem_base;
+
 
 struct pci_controller *pcibios_alloc_controller(struct device_node *dev)
 {
diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 096c97e03aa655d1e723cc579da9252929e7cad6..a33c2820c20092756e1333817792ba202db5ab57 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -32,7 +32,6 @@
 #endif
 
 unsigned long isa_io_base     = 0;
-unsigned long isa_mem_base    = 0;
 unsigned long pci_dram_offset = 0;
 int pcibios_assign_bus_offset = 1;
 
diff --git a/include/asm-powerpc/io.h b/include/asm-powerpc/io.h
index e44cdfc8493a8f30a2b4a4644884c429f5b1f966..7be26f615755ad5a80c84aa3867facf781f3db03 100644
--- a/include/asm-powerpc/io.h
+++ b/include/asm-powerpc/io.h
@@ -50,15 +50,16 @@ extern int check_legacy_ioport(unsigned long base_port);
 #define PCI_DRAM_OFFSET	pci_dram_offset
 #else
 #define _IO_BASE	pci_io_base
-#define _ISA_MEM_BASE	0
+#define _ISA_MEM_BASE	isa_mem_base
 #define PCI_DRAM_OFFSET	0
 #endif
 
 extern unsigned long isa_io_base;
-extern unsigned long isa_mem_base;
 extern unsigned long pci_io_base;
 extern unsigned long pci_dram_offset;
 
+extern resource_size_t isa_mem_base;
+
 #if defined(CONFIG_PPC32) && defined(CONFIG_PPC_INDIRECT_IO)
 #error CONFIG_PPC_INDIRECT_IO is not yet supported on 32 bits
 #endif