diff --git a/include/asm-mips/dec/ioasic_addrs.h b/include/asm-mips/dec/ioasic_addrs.h
index 5e18a75..4cbc1f8 100644
--- a/include/asm-mips/dec/ioasic_addrs.h
+++ b/include/asm-mips/dec/ioasic_addrs.h
@@ -45,7 +45,8 @@
 
 
 /*
- * Offsets for I/O ASIC registers (relative to (system_base + IOASIC_IOCTL)).
+ * Offsets for I/O ASIC registers
+ * (relative to (dec_kn_slot_base + IOASIC_IOCTL)).
  */
 					/* all systems */
 #define IO_REG_SCSI_DMA_P	0x00	/* SCSI DMA Pointer */
diff --git a/include/asm-mips/dec/kn01.h b/include/asm-mips/dec/kn01.h
index 607a385..eb522aa 100644
--- a/include/asm-mips/dec/kn01.h
+++ b/include/asm-mips/dec/kn01.h
@@ -13,9 +13,7 @@
 #ifndef __ASM_MIPS_DEC_KN01_H
 #define __ASM_MIPS_DEC_KN01_H
 
-#include <asm/addrspace.h>
-
-#define KN01_SLOT_BASE	CKSEG1ADDR(0x10000000)
+#define KN01_SLOT_BASE	0x10000000
 #define KN01_SLOT_SIZE	0x01000000
 
 /*
@@ -41,17 +39,9 @@
 
 
 /*
- * Some port addresses...
- */
-#define KN01_LANCE_BASE (KN01_SLOT_BASE + KN01_LANCE)	/* 0xB8000000 */
-#define KN01_DZ11_BASE	(KN01_SLOT_BASE + KN01_DZ11)	/* 0xBC000000 */
-#define KN01_RTC_BASE	(KN01_SLOT_BASE + KN01_RTC)	/* 0xBD000000 */
-
-
-/*
  * Frame buffer memory address.
  */
-#define KN01_VFB_MEM	CKSEG1ADDR(0x0fc00000)
+#define KN01_VFB_MEM	0x0fc00000
 
 /*
  * CPU interrupt bits.
diff --git a/include/asm-mips/dec/kn02.h b/include/asm-mips/dec/kn02.h
index 83a042e..8319ad7 100644
--- a/include/asm-mips/dec/kn02.h
+++ b/include/asm-mips/dec/kn02.h
@@ -13,11 +13,7 @@
 #ifndef __ASM_MIPS_DEC_KN02_H
 #define __ASM_MIPS_DEC_KN02_H
 
-#include <asm/addrspace.h>
-#include <asm/dec/ecc.h>
-
-
-#define KN02_SLOT_BASE	CKSEG1ADDR(0x1fc00000)
+#define KN02_SLOT_BASE	0x1fc00000
 #define KN02_SLOT_SIZE	0x00080000
 
 /*
@@ -34,14 +30,6 @@
 
 
 /*
- * Some port addresses...
- */
-#define KN02_DZ11_BASE	(KN02_SLOT_BASE + KN02_DZ11)	/* DZ11 */
-#define KN02_RTC_BASE	(KN02_SLOT_BASE + KN02_RTC)	/* RTC */
-#define KN02_CSR_BASE	(KN02_SLOT_BASE + KN02_CSR)	/* CSR */
-
-
-/*
  * System Control & Status Register bits.
  */
 #define KN02_CSR_RES_28		(0xf<<28)	/* unused */
diff --git a/include/asm-mips/dec/kn02xa.h b/include/asm-mips/dec/kn02xa.h
index 3c25a33..a25f3d7 100644
--- a/include/asm-mips/dec/kn02xa.h
+++ b/include/asm-mips/dec/kn02xa.h
@@ -17,31 +17,23 @@
 #ifndef __ASM_MIPS_DEC_KN02XA_H
 #define __ASM_MIPS_DEC_KN02XA_H
 
-#include <asm/addrspace.h>
 #include <asm/dec/ioasic_addrs.h>
 
-#define KN02XA_SLOT_BASE	CKSEG1ADDR(0x1c000000)
-
-/*
- * Some port addresses...
- */
-#define KN02XA_IOASIC_BASE    (KN02XA_SLOT_BASE + IOASIC_IOCTL)	/* I/O ASIC */
-#define KN02XA_RTC_BASE		(KN02XA_SLOT_BASE + IOASIC_TOY)	/* RTC */
-
+#define KN02XA_SLOT_BASE	0x1c000000
 
 /*
  * Memory control ASIC registers.
  */
-#define KN02XA_MER	CKSEG1ADDR(0x0c400000)	/* memory error register */
-#define KN02XA_MSR	CKSEG1ADDR(0x0c800000)	/* memory size register */
+#define KN02XA_MER		0x0c400000	/* memory error register */
+#define KN02XA_MSR		0x0c800000	/* memory size register */
 
 /*
  * CPU control ASIC registers.
  */
-#define KN02XA_MEM_CONF	CKSEG1ADDR(0x0e000000)	/* write timeout config */
-#define KN02XA_EAR	CKSEG1ADDR(0x0e000004)	/* error address register */
-#define KN02XA_BOOT0	CKSEG1ADDR(0x0e000008)	/* boot 0 register */
-#define KN02XA_MEM_INTR	CKSEG1ADDR(0x0e00000c)	/* write err IRQ stat & ack */
+#define KN02XA_MEM_CONF		0x0e000000	/* write timeout config */
+#define KN02XA_EAR		0x0e000004	/* error address register */
+#define KN02XA_BOOT0		0x0e000008	/* boot 0 register */
+#define KN02XA_MEM_INTR		0x0e00000c	/* write err IRQ stat & ack */
 
 /*
  * Memory Error Register bits, common definitions.
diff --git a/include/asm-mips/dec/kn03.h b/include/asm-mips/dec/kn03.h
index 9d787cc..edede92 100644
--- a/include/asm-mips/dec/kn03.h
+++ b/include/asm-mips/dec/kn03.h
@@ -10,24 +10,15 @@
  *
  * Copyright (C) 1995,1996 by Paul M. Antoine, some code and definitions
  * are by courtesy of Chris Fraser.
- * Copyright (C) 2000, 2002, 2003  Maciej W. Rozycki
+ * Copyright (C) 2000, 2002, 2003, 2005  Maciej W. Rozycki
  */
 #ifndef __ASM_MIPS_DEC_KN03_H
 #define __ASM_MIPS_DEC_KN03_H
 
-#include <asm/addrspace.h>
 #include <asm/dec/ecc.h>
 #include <asm/dec/ioasic_addrs.h>
 
-#define KN03_SLOT_BASE	CKSEG1ADDR(0x1f800000)
-
-/*
- * Some port addresses...
- */
-#define KN03_IOASIC_BASE	(KN03_SLOT_BASE + IOASIC_IOCTL)	/* I/O ASIC */
-#define KN03_RTC_BASE		(KN03_SLOT_BASE + IOASIC_TOY)	/* RTC */
-#define KN03_MCR_BASE		(KN03_SLOT_BASE + IOASIC_MCR)	/* MCR */
-
+#define KN03_SLOT_BASE		0x1f800000
 
 /*
  * CPU interrupt bits.
diff --git a/include/asm-mips/dec/kn05.h b/include/asm-mips/dec/kn05.h
index 61feac3..15fe8f8 100644
--- a/include/asm-mips/dec/kn05.h
+++ b/include/asm-mips/dec/kn05.h
@@ -21,7 +21,6 @@
 #ifndef __ASM_MIPS_DEC_KN05_H
 #define __ASM_MIPS_DEC_KN05_H
 
-#include <asm/addrspace.h>
 #include <asm/dec/ioasic_addrs.h>
 
 /*
@@ -30,7 +29,7 @@
  * passed to the I/O ASIC's decoder like with the KN03 or KN02-BA/CA.
  * Others are handled locally.  "Low" slots are always passed.
  */
-#define KN4K_SLOT_BASE	KSEG1ADDR(0x1fc00000)
+#define KN4K_SLOT_BASE	0x1fc00000
 
 #define KN4K_MB_ROM	(0*IOASIC_SLOT_SIZE)	/* KN05/KN04 card ROM */
 #define KN4K_IOCTL	(1*IOASIC_SLOT_SIZE)	/* I/O ASIC */
diff --git a/include/asm-mips/dec/system.h b/include/asm-mips/dec/system.h
new file mode 100644
index 0000000..78af51f
--- /dev/null
+++ b/include/asm-mips/dec/system.h
@@ -0,0 +1,18 @@
+/*
+ *	include/asm-mips/dec/system.h
+ *
+ *	Generic DECstation/DECsystem bits.
+ *
+ *	Copyright (C) 2005  Maciej W. Rozycki
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+#ifndef __ASM_DEC_SYSTEM_H
+#define __ASM_DEC_SYSTEM_H
+
+extern unsigned long dec_kn_slot_base, dec_kn_slot_size;
+
+#endif /* __ASM_DEC_SYSTEM_H */
diff --git a/include/asm-mips/dec/tc.h b/include/asm-mips/dec/tc.h
index d7bba43..9cb51f2 100644
--- a/include/asm-mips/dec/tc.h
+++ b/include/asm-mips/dec/tc.h
@@ -7,10 +7,8 @@
  *
  * Copyright (c) 1998 Harald Koerfgen
  */
-#ifndef ASM_TC_H
-#define ASM_TC_H
-
-extern unsigned long system_base;
+#ifndef __ASM_DEC_TC_H
+#define __ASM_DEC_TC_H
 
 /*
  * Search for a TURBOchannel Option Module
@@ -36,8 +34,8 @@
  */
 extern unsigned long get_tc_irq_nr(int);
 /*
- * Return TURBOchannel clock frequency in hz
+ * Return TURBOchannel clock frequency in Hz
  */
 extern unsigned long get_tc_speed(void);
 
-#endif
+#endif /* __ASM_DEC_TC_H */
diff --git a/include/asm-mips/mach-dec/mc146818rtc.h b/include/asm-mips/mach-dec/mc146818rtc.h
index a326f45..6d37a56 100644
--- a/include/asm-mips/mach-dec/mc146818rtc.h
+++ b/include/asm-mips/mach-dec/mc146818rtc.h
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1998, 2001 by Ralf Baechle
  * Copyright (C) 1998 by Harald Koerfgen
- * Copyright (C) 2002  Maciej W. Rozycki
+ * Copyright (C) 2002, 2005  Maciej W. Rozycki
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -14,23 +14,18 @@
 #define __ASM_MIPS_DEC_RTC_DEC_H
 
 #include <linux/types.h>
-
 #include <asm/addrspace.h>
+#include <asm/dec/system.h>
 
 extern volatile u8 *dec_rtc_base;
-extern unsigned long dec_kn_slot_size;
 
-#define RTC_PORT(x)	CPHYSADDR(dec_rtc_base)
+#define RTC_PORT(x)	CPHYSADDR((long)dec_rtc_base)
 #define RTC_IO_EXTENT	dec_kn_slot_size
 #define RTC_IOMAPPED	0
 #undef RTC_IRQ
 
 #define RTC_DEC_YEAR	0x3f	/* Where we store the real year on DECs.  */
 
-#include <linux/mc146818rtc.h>
-#include <linux/module.h>
-#include <linux/types.h>
-
 static inline unsigned char CMOS_READ(unsigned long addr)
 {
 	return dec_rtc_base[addr * 4];