diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2ad3e29f0ebe..6bc60f964f96 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -125,7 +125,8 @@ config ARCH_HAS_ILOG2_U64
 
 config NO_IOPORT_MAP
 	def_bool !PCI
-	depends on !SH_SHMIN && !SH_HP6XX && !SH_SOLUTION_ENGINE
+	depends on !SH_SHMIN && !SH_HP6XX && !SH_SOLUTION_ENGINE && \
+		   !SH_DREAMCAST
 
 config IO_TRAPPED
 	bool
diff --git a/arch/sh/boards/mach-dreamcast/setup.c b/arch/sh/boards/mach-dreamcast/setup.c
index 2d966c1c2cc1..daa8455549fa 100644
--- a/arch/sh/boards/mach-dreamcast/setup.c
+++ b/arch/sh/boards/mach-dreamcast/setup.c
@@ -25,10 +25,13 @@
 #include <asm/irq.h>
 #include <asm/rtc.h>
 #include <asm/machvec.h>
+#include <cpu/addrspace.h>
 #include <mach/sysasic.h>
 
 static void __init dreamcast_setup(char **cmdline_p)
 {
+	/* GAPS PCI bridge assumes P2 area relative addresses. */
+	__set_io_port_base(P2SEG);
 }
 
 static struct sh_machine_vector mv_dreamcast __initmv = {