diff --git a/arch/sparc/include/asm/spitfire.h b/arch/sparc/include/asm/spitfire.h
index 1d8321c827a8821bb4e9f4989eb883cd761370db..1b1286d0506910c0f9a92ab6af14e272dd008d61 100644
--- a/arch/sparc/include/asm/spitfire.h
+++ b/arch/sparc/include/asm/spitfire.h
@@ -47,10 +47,26 @@
 #define SUN4V_CHIP_NIAGARA5	0x05
 #define SUN4V_CHIP_SPARC_M6	0x06
 #define SUN4V_CHIP_SPARC_M7	0x07
+#define SUN4V_CHIP_SPARC_M8	0x08
 #define SUN4V_CHIP_SPARC64X	0x8a
 #define SUN4V_CHIP_SPARC_SN	0x8b
 #define SUN4V_CHIP_UNKNOWN	0xff
 
+/*
+ * The following CPU_ID_xxx constants are used
+ * to identify the CPU type in the setup phase
+ * (see head_64.S)
+ */
+#define CPU_ID_NIAGARA1		('1')
+#define CPU_ID_NIAGARA2		('2')
+#define CPU_ID_NIAGARA3		('3')
+#define CPU_ID_NIAGARA4		('4')
+#define CPU_ID_NIAGARA5		('5')
+#define CPU_ID_M6		('6')
+#define CPU_ID_M7		('7')
+#define CPU_ID_M8		('8')
+#define CPU_ID_SONOMA1		('N')
+
 #ifndef __ASSEMBLY__
 
 enum ultra_tlb_layout {
diff --git a/arch/sparc/kernel/cpu.c b/arch/sparc/kernel/cpu.c
index 493e023a468a919c61d77451e43e0a4a2e414bbe..ef4f18f7a67402ed8baceb2ea05ee7f6368cc404 100644
--- a/arch/sparc/kernel/cpu.c
+++ b/arch/sparc/kernel/cpu.c
@@ -506,6 +506,12 @@ static void __init sun4v_cpu_probe(void)
 		sparc_pmu_type = "sparc-m7";
 		break;
 
+	case SUN4V_CHIP_SPARC_M8:
+		sparc_cpu_type = "SPARC-M8";
+		sparc_fpu_type = "SPARC-M8 integrated FPU";
+		sparc_pmu_type = "sparc-m8";
+		break;
+
 	case SUN4V_CHIP_SPARC_SN:
 		sparc_cpu_type = "SPARC-SN";
 		sparc_fpu_type = "SPARC-SN integrated FPU";
diff --git a/arch/sparc/kernel/cpumap.c b/arch/sparc/kernel/cpumap.c
index 45c820e1cba5d949ff936f15392ca3c0c8578a34..90d550bbfeefe484f1560940f111235f26332d7a 100644
--- a/arch/sparc/kernel/cpumap.c
+++ b/arch/sparc/kernel/cpumap.c
@@ -328,6 +328,7 @@ static int iterate_cpu(struct cpuinfo_tree *t, unsigned int root_index)
 	case SUN4V_CHIP_NIAGARA5:
 	case SUN4V_CHIP_SPARC_M6:
 	case SUN4V_CHIP_SPARC_M7:
+	case SUN4V_CHIP_SPARC_M8:
 	case SUN4V_CHIP_SPARC_SN:
 	case SUN4V_CHIP_SPARC64X:
 		rover_inc_table = niagara_iterate_method;
diff --git a/arch/sparc/kernel/head_64.S b/arch/sparc/kernel/head_64.S
index 41a4073286671eff51f275bfca4ae6d9d01db74d..78e0211753d28f14f955af865704248b1e5daf24 100644
--- a/arch/sparc/kernel/head_64.S
+++ b/arch/sparc/kernel/head_64.S
@@ -424,22 +424,25 @@ EXPORT_SYMBOL(sun4v_chip_type)
 	 nop
 
 70:	ldub	[%g1 + 7], %g2
-	cmp	%g2, '3'
+	cmp	%g2, CPU_ID_NIAGARA3
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_NIAGARA3, %g4
-	cmp	%g2, '4'
+	cmp	%g2, CPU_ID_NIAGARA4
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_NIAGARA4, %g4
-	cmp	%g2, '5'
+	cmp	%g2, CPU_ID_NIAGARA5
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_NIAGARA5, %g4
-	cmp	%g2, '6'
+	cmp	%g2, CPU_ID_M6
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_SPARC_M6, %g4
-	cmp	%g2, '7'
+	cmp	%g2, CPU_ID_M7
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_SPARC_M7, %g4
-	cmp	%g2, 'N'
+	cmp	%g2, CPU_ID_M8
+	be,pt	%xcc, 5f
+	 mov	SUN4V_CHIP_SPARC_M8, %g4
+	cmp	%g2, CPU_ID_SONOMA1
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_SPARC_SN, %g4
 	ba,pt	%xcc, 49f
@@ -448,10 +451,10 @@ EXPORT_SYMBOL(sun4v_chip_type)
 91:	sethi	%hi(prom_cpu_compatible), %g1
 	or	%g1, %lo(prom_cpu_compatible), %g1
 	ldub	[%g1 + 17], %g2
-	cmp	%g2, '1'
+	cmp	%g2, CPU_ID_NIAGARA1
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_NIAGARA1, %g4
-	cmp	%g2, '2'
+	cmp	%g2, CPU_ID_NIAGARA2
 	be,pt	%xcc, 5f
 	 mov	SUN4V_CHIP_NIAGARA2, %g4
 	
@@ -600,6 +603,9 @@ niagara_tlb_fixup:
 	be,pt	%xcc, niagara4_patch
 	 nop
 	cmp	%g1, SUN4V_CHIP_SPARC_M7
+	be,pt	%xcc, niagara4_patch
+	 nop
+	cmp	%g1, SUN4V_CHIP_SPARC_M8
 	be,pt	%xcc, niagara4_patch
 	 nop
 	cmp	%g1, SUN4V_CHIP_SPARC_SN
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index 4d9c3e13c15056b5d60e7ccd266b36cfe29d2c00..150ee7d4b059a69e174dff7c7d16ff906f73e1ed 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -288,10 +288,17 @@ static void __init sun4v_patch(void)
 
 	sun4v_patch_2insn_range(&__sun4v_2insn_patch,
 				&__sun4v_2insn_patch_end);
-	if (sun4v_chip_type == SUN4V_CHIP_SPARC_M7 ||
-	    sun4v_chip_type == SUN4V_CHIP_SPARC_SN)
+
+	switch (sun4v_chip_type) {
+	case SUN4V_CHIP_SPARC_M7:
+	case SUN4V_CHIP_SPARC_M8:
+	case SUN4V_CHIP_SPARC_SN:
 		sun_m7_patch_2insn_range(&__sun_m7_2insn_patch,
 					 &__sun_m7_2insn_patch_end);
+		break;
+	default:
+		break;
+	}
 
 	sun4v_hvapi_init();
 }
@@ -529,6 +536,7 @@ static void __init init_sparc64_elf_hwcap(void)
 		    sun4v_chip_type == SUN4V_CHIP_NIAGARA5 ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC_M6 ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC_M7 ||
+		    sun4v_chip_type == SUN4V_CHIP_SPARC_M8 ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC_SN ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC64X)
 			cap |= HWCAP_SPARC_BLKINIT;
@@ -538,6 +546,7 @@ static void __init init_sparc64_elf_hwcap(void)
 		    sun4v_chip_type == SUN4V_CHIP_NIAGARA5 ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC_M6 ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC_M7 ||
+		    sun4v_chip_type == SUN4V_CHIP_SPARC_M8 ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC_SN ||
 		    sun4v_chip_type == SUN4V_CHIP_SPARC64X)
 			cap |= HWCAP_SPARC_N2;
@@ -568,6 +577,7 @@ static void __init init_sparc64_elf_hwcap(void)
 			    sun4v_chip_type == SUN4V_CHIP_NIAGARA5 ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC_M6 ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC_M7 ||
+			    sun4v_chip_type == SUN4V_CHIP_SPARC_M8 ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC_SN ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC64X)
 				cap |= (AV_SPARC_VIS | AV_SPARC_VIS2 |
@@ -578,6 +588,7 @@ static void __init init_sparc64_elf_hwcap(void)
 			    sun4v_chip_type == SUN4V_CHIP_NIAGARA5 ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC_M6 ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC_M7 ||
+			    sun4v_chip_type == SUN4V_CHIP_SPARC_M8 ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC_SN ||
 			    sun4v_chip_type == SUN4V_CHIP_SPARC64X)
 				cap |= (AV_SPARC_VIS3 | AV_SPARC_HPC |
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index fed73f14aa49befee59b93b0fcab02f65f7e10d2..afa0099f374852e0cf093088d942512008a45a68 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -1944,12 +1944,22 @@ static void __init setup_page_offset(void)
 			break;
 		case SUN4V_CHIP_SPARC_M7:
 		case SUN4V_CHIP_SPARC_SN:
-		default:
 			/* M7 and later support 52-bit virtual addresses.  */
 			sparc64_va_hole_top =    0xfff8000000000000UL;
 			sparc64_va_hole_bottom = 0x0008000000000000UL;
 			max_phys_bits = 49;
 			break;
+		case SUN4V_CHIP_SPARC_M8:
+		default:
+			/* M8 and later support 54-bit virtual addresses.
+			 * However, restricting M8 and above VA bits to 53
+			 * as 4-level page table cannot support more than
+			 * 53 VA bits.
+			 */
+			sparc64_va_hole_top =    0xfff0000000000000UL;
+			sparc64_va_hole_bottom = 0x0010000000000000UL;
+			max_phys_bits = 51;
+			break;
 		}
 	}
 
@@ -2161,6 +2171,7 @@ static void __init sun4v_linear_pte_xor_finalize(void)
 	 */
 	switch (sun4v_chip_type) {
 	case SUN4V_CHIP_SPARC_M7:
+	case SUN4V_CHIP_SPARC_M8:
 	case SUN4V_CHIP_SPARC_SN:
 		pagecv_flag = 0x00;
 		break;
@@ -2313,6 +2324,7 @@ void __init paging_init(void)
 	 */
 	switch (sun4v_chip_type) {
 	case SUN4V_CHIP_SPARC_M7:
+	case SUN4V_CHIP_SPARC_M8:
 	case SUN4V_CHIP_SPARC_SN:
 		page_cache4v_flag = _PAGE_CP_4V;
 		break;
diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 6b16ead1da5871abcef5b2233733f281158596a8..ad9749463d4fa9a382afa7f24587bbbe3a2efcc9 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -875,6 +875,56 @@ static void print_version(void)
 		printk(KERN_INFO "%s", version);
 }
 
+struct vdc_check_port_data {
+	int	dev_no;
+	char	*type;
+};
+
+static int vdc_device_probed(struct device *dev, void *arg)
+{
+	struct vio_dev *vdev = to_vio_dev(dev);
+	struct vdc_check_port_data *port_data;
+
+	port_data = (struct vdc_check_port_data *)arg;
+
+	if ((vdev->dev_no == port_data->dev_no) &&
+	    (!(strcmp((char *)&vdev->type, port_data->type))) &&
+		dev_get_drvdata(dev)) {
+		/* This device has already been configured
+		 * by vdc_port_probe()
+		 */
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+/* Determine whether the VIO device is part of an mpgroup
+ * by locating all the virtual-device-port nodes associated
+ * with the parent virtual-device node for the VIO device
+ * and checking whether any of these nodes are vdc-ports
+ * which have already been configured.
+ *
+ * Returns true if this device is part of an mpgroup and has
+ * already been probed.
+ */
+static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
+{
+	struct vdc_check_port_data port_data;
+	struct device *dev;
+
+	port_data.dev_no = vdev->dev_no;
+	port_data.type = (char *)&vdev->type;
+
+	dev = device_find_child(vdev->dev.parent, &port_data,
+				vdc_device_probed);
+
+	if (dev)
+		return true;
+
+	return false;
+}
+
 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 {
 	struct mdesc_handle *hp;
@@ -893,6 +943,14 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 		goto err_out_release_mdesc;
 	}
 
+	/* Check if this device is part of an mpgroup */
+	if (vdc_port_mpgroup_check(vdev)) {
+		printk(KERN_WARNING
+			"VIO: Ignoring extra vdisk port %s",
+			dev_name(&vdev->dev));
+		goto err_out_release_mdesc;
+	}
+
 	port = kzalloc(sizeof(*port), GFP_KERNEL);
 	err = -ENOMEM;
 	if (!port) {
@@ -943,6 +1001,9 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 	if (err)
 		goto err_out_free_tx_ring;
 
+	/* Note that the device driver_data is used to determine
+	 * whether the port has been probed.
+	 */
 	dev_set_drvdata(&vdev->dev, port);
 
 	mdesc_release(hp);