diff -urN linux-2.6.22-rc6/arch/mips/philips/pnx8550/common/setup.c linux-2.6.22-rc6-new/arch/mips/philips/pnx8550/common/setup.c
--- linux-2.6.22-rc6/arch/mips/philips/pnx8550/common/setup.c	2007-06-25 11:12:54.000000000 +0100
+++ linux-2.6.22-rc6-new/arch/mips/philips/pnx8550/common/setup.c	2007-06-27 15:07:29.000000000 +0100
@@ -75,6 +75,20 @@
 	},
 };
 
+/* Define the CMEM regions for the processor. */
+#define CMEM_VALID       (1 << PR4450_CMEMB_VALID)
+#define MMIO_CMEM_REGION (0x1be00000 & PR4450_CMEMF_BBA)
+#define MMIO_CMEM_SIZE   (PR4450_CMEM_SIZE_2MB << PR4450_CMEMB_SIZE)
+#define MMIO_CMEM_ENABLE (MMIO_CMEM_REGION | MMIO_CMEM_SIZE | CMEM_VALID)
+
+#define XIO_CMEM_REGION  (0x10000000 & PR4450_CMEMF_BBA)
+#define XIO_CMEM_SIZE    (PR4450_CMEM_SIZE_128MB << PR4450_CMEMB_SIZE)
+#define XIO_CMEM_ENABLE  (XIO_CMEM_REGION | XIO_CMEM_SIZE | CMEM_VALID)
+
+#define PCI_CMEM_REGION  (0x20000000 & PR4450_CMEMF_BBA)
+#define PCI_CMEM_SIZE    (PR4450_CMEM_SIZE_128MB << PR4450_CMEMB_SIZE)
+#define PCI_CMEM_ENABLE  (PCI_CMEM_REGION | PCI_CMEM_SIZE | CMEM_VALID)
+
 #define STANDARD_IO_RESOURCES (sizeof(standard_io_resources)/sizeof(struct resource))
 
 extern struct resource pci_io_resource;
@@ -106,6 +120,19 @@
 
 	board_time_init = pnx8550_time_init;
 
+	/* Setup CMEM Registers */
+	/* CMEM0 = MMIO */
+	write_c0_diag4(MMIO_CMEM_ENABLE);
+
+	/* CMEM1 = XIO */
+	write_c0_diag5(XIO_CMEM_ENABLE);
+
+	/* CMEM2 = PCI */
+	write_c0_diag6(PCI_CMEM_ENABLE);
+
+	/* CMEM3 = Not used */
+	write_c0_diag7(0);
+
 	/* Clear the Global 2 Register, PCI Inta Output Enable Registers
 	   Bit 1:Enable DAC Powerdown
 	  -> 0:DACs are enabled and are working normally
diff -urN linux-2.6.22-rc6/include/asm-mips/mipsregs.h linux-2.6.22-rc6-new/include/asm-mips/mipsregs.h
--- linux-2.6.22-rc6/include/asm-mips/mipsregs.h	2007-06-25 11:12:54.000000000 +0100
+++ linux-2.6.22-rc6-new/include/asm-mips/mipsregs.h	2007-06-27 15:07:29.000000000 +0100
@@ -498,6 +498,25 @@
 #define MIPS_CONF_AT		(_ULCAST_(3) << 13)
 #define MIPS_CONF_M		(_ULCAST_(1) << 31)
 
+/* Bits specific to the PR4450 CMEM Registers */
+#define PR4450_CMEMF_BBA     (_ULCAST_(2047) << 20)
+#define PR4450_CMEMB_BBA     20
+#define PR4450_CMEMF_SIZE    (_ULCAST_(15) << 1)
+#define PR4450_CMEMB_SIZE    1
+#define PR4450_CMEM_SIZE_1MB    0
+#define PR4450_CMEM_SIZE_2MB    1
+#define PR4450_CMEM_SIZE_4MB    2
+#define PR4450_CMEM_SIZE_8MB    3
+#define PR4450_CMEM_SIZE_16MB   4
+#define PR4450_CMEM_SIZE_32MB   5
+#define PR4450_CMEM_SIZE_64MB   6
+#define PR4450_CMEM_SIZE_128MB  7
+#define PR4450_CMEM_SIZE_256MB  8
+#define PR4450_CMEM_SIZE_512MB  9
+#define PR4450_CMEM_SIZE_1GB   10
+#define PR4450_CMEMF_VALID   (_ULCAST_(1) << 0)
+#define PR4450_CMEMB_VALID   0
+
 /*
  * Bits in the MIPS32/64 PRA coprocessor 0 config registers 1 and above.
  */
@@ -919,6 +938,14 @@
 #define read_c0_diag5()		__read_32bit_c0_register($22, 5)
 #define write_c0_diag5(val)	__write_32bit_c0_register($22, 5, val)
 
+#ifdef CONFIG_SOC_PNX8550
+#define read_c0_diag6()		__read_32bit_c0_register($22, 6)
+#define write_c0_diag6(val)	__write_32bit_c0_register($22, 6, val)
+
+#define read_c0_diag7()		__read_32bit_c0_register($22, 7)
+#define write_c0_diag7(val)	__write_32bit_c0_register($22, 7, val)
+#endif
+
 #define read_c0_debug()		__read_32bit_c0_register($23, 0)
 #define write_c0_debug(val)	__write_32bit_c0_register($23, 0, val)