diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 96316c8..0e564d3 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -160,9 +160,11 @@
 
 config 40x
 	bool "AMCC 40x"
+	select PPC_DCR_NATIVE
 
 config 44x
 	bool "AMCC 44x"
+	select PPC_DCR_NATIVE
 
 config 8xx
 	bool "Freescale 8xx"
@@ -208,6 +210,19 @@
 	bool
 	default y if PPC64
 
+config PPC_DCR_NATIVE
+	bool
+	default n
+
+config PPC_DCR_MMIO
+	bool
+	default n
+
+config PPC_DCR
+	bool
+	depends on PPC_DCR_NATIVE || PPC_DCR_MMIO
+	default y
+
 config BOOKE
 	bool
 	depends on E200 || E500
@@ -453,6 +468,7 @@
 config PPC_CELL_NATIVE
 	bool
 	select PPC_CELL
+	select PPC_DCR_MMIO
 	default n
 
 config PPC_IBM_CELL_BLADE
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d8240ce..f34d158 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -58,6 +58,7 @@
 obj-$(CONFIG_SMP)		+= smp.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_PPC_UDBG_16550)	+= legacy_serial.o udbg_16550.o
+
 module-$(CONFIG_PPC64)		+= module_64.o
 obj-$(CONFIG_MODULES)		+= $(module-y)
 
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 5b87f7b..8ba11ab 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -5,8 +5,7 @@
 obj-$(CONFIG_MPIC)		+= mpic.o
 obj-$(CONFIG_PPC_INDIRECT_PCI)	+= indirect_pci.o
 obj-$(CONFIG_PPC_MPC106)	+= grackle.o
-obj-$(CONFIG_BOOKE)		+= dcr.o
-obj-$(CONFIG_40x)		+= dcr.o
+obj-$(CONFIG_PPC_DCR)		+= dcr.o dcr-low.o
 obj-$(CONFIG_U3_DART)		+= dart_iommu.o
 obj-$(CONFIG_MMIO_NVRAM)	+= mmio_nvram.o
 obj-$(CONFIG_FSL_SOC)		+= fsl_soc.o
diff --git a/arch/powerpc/sysdev/dcr-low.S b/arch/powerpc/sysdev/dcr-low.S
new file mode 100644
index 0000000..2078f39
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr-low.S
@@ -0,0 +1,39 @@
+/*
+ * "Indirect" DCR access
+ *
+ * Copyright (c) 2004 Eugene Surovegin <ebs@ebshome.net>
+ *
+ * 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.
+ */
+
+#include <asm/ppc_asm.h>
+#include <asm/processor.h>
+
+#define DCR_ACCESS_PROLOG(table) \
+	rlwinm  r3,r3,4,18,27;   \
+	lis     r5,table@h;      \
+	ori     r5,r5,table@l;   \
+	add     r3,r3,r5;        \
+	mtctr   r3;              \
+	bctr
+
+_GLOBAL(__mfdcr)
+	DCR_ACCESS_PROLOG(__mfdcr_table)
+
+_GLOBAL(__mtdcr)
+	DCR_ACCESS_PROLOG(__mtdcr_table)
+
+__mfdcr_table:
+	mfdcr  r3,0; blr
+__mtdcr_table:
+	mtdcr  0,r4; blr
+
+dcr     = 1
+        .rept   1023
+	mfdcr   r3,dcr; blr
+	mtdcr   dcr,r4; blr
+	dcr     = dcr + 1
+	.endr
diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
new file mode 100644
index 0000000..dffeeae
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr.c
@@ -0,0 +1,137 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ *   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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <asm/prom.h>
+#include <asm/dcr.h>
+
+unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
+{
+	unsigned int ds;
+	const u32 *dr = get_property(np, "dcr-reg", &ds);
+
+	if (dr == NULL || ds & 1 || index >= (ds / 8))
+		return 0;
+
+	return dr[index * 2];
+}
+
+unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
+{
+	unsigned int ds;
+	const u32 *dr = get_property(np, "dcr-reg", &ds);
+
+	if (dr == NULL || ds & 1 || index >= (ds / 8))
+		return 0;
+
+	return dr[index * 2 + 1];
+}
+
+#ifndef CONFIG_PPC_DCR_NATIVE
+
+static struct device_node * find_dcr_parent(struct device_node * node)
+{
+	struct device_node *par, *tmp;
+	const u32 *p;
+
+	for (par = of_node_get(node); par;) {
+		if (get_property(par, "dcr-controller", NULL))
+			break;
+		p = get_property(par, "dcr-parent", NULL);
+		tmp = par;
+		if (p == NULL)
+			par = of_get_parent(par);
+		else
+			par = of_find_node_by_phandle(*p);
+		of_node_put(tmp);
+	}
+	return par;
+}
+
+u64 of_translate_dcr_address(struct device_node *dev,
+			     unsigned int dcr_n,
+			     unsigned int *out_stride)
+{
+	struct device_node *dp;
+	const u32 *p;
+	unsigned int stride;
+	u64 ret;
+
+	dp = find_dcr_parent(dev);
+	if (dp == NULL)
+		return OF_BAD_ADDR;
+
+	/* Stride is not properly defined yet, default to 0x10 for Axon */
+	p = get_property(dp, "dcr-mmio-stride", NULL);
+	stride = (p == NULL) ? 0x10 : *p;
+
+	/* XXX FIXME: Which property name is to use of the 2 following ? */
+	p = get_property(dp, "dcr-mmio-range", NULL);
+	if (p == NULL)
+		p = get_property(dp, "dcr-mmio-space", NULL);
+	if (p == NULL)
+		return OF_BAD_ADDR;
+
+	/* Maybe could do some better range checking here */
+	ret = of_translate_address(dp, p);
+	if (ret != OF_BAD_ADDR)
+		ret += (u64)(stride) * (u64)dcr_n;
+	if (out_stride)
+		*out_stride = stride;
+	return ret;
+}
+
+dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
+		   unsigned int dcr_c)
+{
+	dcr_host_t ret = { .token = NULL, .stride = 0 };
+	u64 addr;
+
+	pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
+		 dev->full_name, dcr_n, dcr_c);
+
+	addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
+	pr_debug("translates to addr: 0x%lx, stride: 0x%x\n",
+		 addr, ret.stride);
+	if (addr == OF_BAD_ADDR)
+		return ret;
+	pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
+	ret.token = ioremap(addr, dcr_c * ret.stride);
+	if (ret.token == NULL)
+		return ret;
+	pr_debug("mapped at 0x%p -> base is 0x%p\n",
+		 ret.token, ret.token - dcr_n * ret.stride);
+	ret.token -= dcr_n * ret.stride;
+	return ret;
+}
+
+void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c)
+{
+	dcr_host_t h = host;
+
+	if (h.token == NULL)
+		return;
+	h.token -= dcr_n * h.stride;
+	iounmap(h.token);
+	h.token = NULL;
+}
+
+#endif /* !defined(CONFIG_PPC_DCR_NATIVE) */
diff --git a/arch/ppc/Kconfig b/arch/ppc/Kconfig
index ef018e2..edf71a4 100644
--- a/arch/ppc/Kconfig
+++ b/arch/ppc/Kconfig
@@ -77,9 +77,11 @@
 
 config 40x
 	bool "40x"
+	select PPC_DCR_NATIVE
 
 config 44x
 	bool "44x"
+	select PPC_DCR_NATIVE
 
 config 8xx
 	bool "8xx"
@@ -95,6 +97,15 @@
 config PPC_FPU
 	bool
 
+config PPC_DCR_NATIVE
+	bool
+	default n
+
+config PPC_DCR
+	bool
+	depends on PPC_DCR_NATIVE
+	default y
+
 config BOOKE
 	bool
 	depends on E200 || E500
diff --git a/include/asm-powerpc/dcr-mmio.h b/include/asm-powerpc/dcr-mmio.h
new file mode 100644
index 0000000..5dbfca8
--- /dev/null
+++ b/include/asm-powerpc/dcr-mmio.h
@@ -0,0 +1,51 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ *   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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_DCR_MMIO_H
+#define _ASM_POWERPC_DCR_MMIO_H
+#ifdef __KERNEL__
+
+#include <asm/io.h>
+
+typedef struct { void __iomem *token; unsigned int stride; } dcr_host_t;
+
+#define DCR_MAP_OK(host)	((host).token != NULL)
+
+extern dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
+			  unsigned int dcr_c);
+extern void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c);
+
+static inline u32 dcr_read(dcr_host_t host, unsigned int dcr_n)
+{
+	return in_be32(host.token + dcr_n * host.stride);
+}
+
+static inline void dcr_write(dcr_host_t host, unsigned int dcr_n, u32 value)
+{
+	out_be32(host.token + dcr_n * host.stride, value);
+}
+
+extern u64 of_translate_dcr_address(struct device_node *dev,
+				    unsigned int dcr_n,
+				    unsigned int *stride);
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_MMIO_H */
+
+
diff --git a/include/asm-powerpc/dcr-native.h b/include/asm-powerpc/dcr-native.h
new file mode 100644
index 0000000..fd4a5f5
--- /dev/null
+++ b/include/asm-powerpc/dcr-native.h
@@ -0,0 +1,39 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ *   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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_DCR_NATIVE_H
+#define _ASM_POWERPC_DCR_NATIVE_H
+#ifdef __KERNEL__
+
+#include <asm/reg.h>
+
+typedef struct {} dcr_host_t;
+
+#define DCR_MAP_OK(host)	(1)
+
+#define dcr_map(dev, dcr_n, dcr_c)	{}
+#define dcr_unmap(host, dcr_n, dcr_c)	{}
+#define dcr_read(host, dcr_n)		mfdcr(dcr_n)
+#define dcr_write(host, dcr_n, value)	mtdcr(dcr_n, value)
+
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_NATIVE_H */
+
+
diff --git a/include/asm-powerpc/dcr.h b/include/asm-powerpc/dcr.h
new file mode 100644
index 0000000..473f2c7
--- /dev/null
+++ b/include/asm-powerpc/dcr.h
@@ -0,0 +1,42 @@
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ *
+ *   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.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_DCR_H
+#define _ASM_POWERPC_DCR_H
+#ifdef __KERNEL__
+
+#ifdef CONFIG_PPC_DCR_NATIVE
+#include <asm/dcr-native.h>
+#else
+#include <asm/dcr-mmio.h>
+#endif
+
+/*
+ * On CONFIG_PPC_MERGE, we have additional helpers to read the DCR
+ * base from the device-tree
+ */
+#ifdef CONFIG_PPC_MERGE
+extern unsigned int dcr_resource_start(struct device_node *np,
+				       unsigned int index);
+extern unsigned int dcr_resource_len(struct device_node *np,
+				     unsigned int index);
+#endif /* CONFIG_PPC_MERGE */
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_H */