diff --git a/Documentation/devicetree/bindings/open-pic.txt b/Documentation/devicetree/bindings/open-pic.txt
new file mode 100644
index 0000000..909a902
--- /dev/null
+++ b/Documentation/devicetree/bindings/open-pic.txt
@@ -0,0 +1,98 @@
+* Open PIC Binding
+
+This binding specifies what properties must be available in the device tree
+representation of an Open PIC compliant interrupt controller.  This binding is
+based on the binding defined for Open PIC in [1] and is a superset of that
+binding.
+
+Required properties:
+
+  NOTE: Many of these descriptions were paraphrased here from [1] to aid
+        readability.
+
+    - compatible: Specifies the compatibility list for the PIC.  The type
+      shall be <string> and the value shall include "open-pic".
+
+    - reg: Specifies the base physical address(s) and size(s) of this
+      PIC's addressable register space.  The type shall be <prop-encoded-array>.
+
+    - interrupt-controller: The presence of this property identifies the node
+      as an Open PIC.  No property value shall be defined.
+
+    - #interrupt-cells: Specifies the number of cells needed to encode an
+      interrupt source.  The type shall be a <u32> and the value shall be 2.
+
+    - #address-cells: Specifies the number of cells needed to encode an
+      address.  The type shall be <u32> and the value shall be 0.  As such,
+      'interrupt-map' nodes do not have to specify a parent unit address.
+
+Optional properties:
+
+    - pic-no-reset: The presence of this property indicates that the PIC
+      shall not be reset during runtime initialization.  No property value shall
+      be defined.  The presence of this property also mandates that any
+      initialization related to interrupt sources shall be limited to sources
+      explicitly referenced in the device tree.
+
+* Interrupt Specifier Definition
+
+  Interrupt specifiers consists of 2 cells encoded as
+  follows:
+
+    - <1st-cell>: The interrupt-number that identifies the interrupt source.
+
+    - <2nd-cell>: The level-sense information, encoded as follows:
+                    0 = low-to-high edge triggered
+                    1 = active low level-sensitive
+                    2 = active high level-sensitive
+                    3 = high-to-low edge triggered
+
+* Examples
+
+Example 1:
+
+	/*
+	 * An Open PIC interrupt controller
+	 */
+	mpic: pic@40000 {
+		// This is an interrupt controller node.
+		interrupt-controller;
+
+		// No address cells so that 'interrupt-map' nodes which reference
+		// this Open PIC node do not need a parent address specifier.
+		#address-cells = <0>;
+
+		// Two cells to encode interrupt sources.
+		#interrupt-cells = <2>;
+
+		// Offset address of 0x40000 and size of 0x40000.
+		reg = <0x40000 0x40000>;
+
+		// Compatible with Open PIC.
+		compatible = "open-pic";
+
+		// The PIC shall not be reset.
+		pic-no-reset;
+	};
+
+Example 2:
+
+	/*
+	 * An interrupt generating device that is wired to an Open PIC.
+	 */
+	serial0: serial@4500 {
+		// Interrupt source '42' that is active high level-sensitive.
+		// Note that there are only two cells as specified in the interrupt
+		// parent's '#interrupt-cells' property.
+		interrupts = <42 2>;
+
+		// The interrupt controller that this device is wired to.
+		interrupt-parent = <&mpic>;
+	};
+
+* References
+
+[1] Power.org (TM) Standard for Embedded Power Architecture (TM) Platform
+    Requirements (ePAPR), Version 1.0, July 2008.
+    (http://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.0.pdf)
+
diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h
index 946ec49..7005ee0 100644
--- a/arch/powerpc/include/asm/mpic.h
+++ b/arch/powerpc/include/asm/mpic.h
@@ -367,6 +367,10 @@
 #define MPIC_SINGLE_DEST_CPU		0x00001000
 /* Enable CoreInt delivery of interrupts */
 #define MPIC_ENABLE_COREINT		0x00002000
+/* Disable resetting of the MPIC.
+ * NOTE: This flag trumps MPIC_WANTS_RESET.
+ */
+#define MPIC_NO_RESET			0x00004000
 
 /* MPIC HW modification ID */
 #define MPIC_REGSET_MASK		0xf0000000
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 0175a67..48223f9 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -125,8 +125,10 @@
 #endif /* ! __powerpc64__ */
 #define TRAP(regs)		((regs)->trap & ~0xF)
 #ifdef __powerpc64__
+#define NV_REG_POISON		0xdeadbeefdeadbeefUL
 #define CHECK_FULL_REGS(regs)	BUG_ON(regs->trap & 1)
 #else
+#define NV_REG_POISON		0xdeadbeef
 #define CHECK_FULL_REGS(regs)						      \
 do {									      \
 	if ((regs)->trap & 1)						      \
diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index 2985268..d225d99 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -176,11 +176,14 @@
  */
 struct device_node *fetch_dev_dn(struct pci_dev *dev)
 {
-	struct device_node *orig_dn = dev->dev.of_node;
+	struct pci_controller *phb = dev->sysdata;
 	struct device_node *dn;
 	unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
 
-	dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
+	if (WARN_ON(!phb))
+		return NULL;
+
+	dn = traverse_pci_devices(phb->dn, is_devfn_node, (void *)searchval);
 	if (dn)
 		dev->dev.of_node = dn;
 	return dn;
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 9065369..895b082 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -229,12 +229,16 @@
 		   unsigned int pos, unsigned int count,
 		   void *kbuf, void __user *ubuf)
 {
-	int ret;
+	int i, ret;
 
 	if (target->thread.regs == NULL)
 		return -EIO;
 
-	CHECK_FULL_REGS(target->thread.regs);
+	if (!FULL_REGS(target->thread.regs)) {
+		/* We have a partial register set.  Fill 14-31 with bogus values */
+		for (i = 14; i < 32; i++)
+			target->thread.regs->gpr[i] = NV_REG_POISON;
+	}
 
 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 				  target->thread.regs,
@@ -641,11 +645,16 @@
 	compat_ulong_t *k = kbuf;
 	compat_ulong_t __user *u = ubuf;
 	compat_ulong_t reg;
+	int i;
 
 	if (target->thread.regs == NULL)
 		return -EIO;
 
-	CHECK_FULL_REGS(target->thread.regs);
+	if (!FULL_REGS(target->thread.regs)) {
+		/* We have a partial register set.  Fill 14-31 with bogus values */
+		for (i = 14; i < 32; i++)
+			target->thread.regs->gpr[i] = NV_REG_POISON; 
+	}
 
 	pos /= sizeof(reg);
 	count /= sizeof(reg);
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index eb70218..0f7c671 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -147,6 +147,16 @@
 
 #endif /* CONFIG_MPIC_WEIRD */
 
+static inline unsigned int mpic_processor_id(struct mpic *mpic)
+{
+	unsigned int cpu = 0;
+
+	if (mpic->flags & MPIC_PRIMARY)
+		cpu = hard_smp_processor_id();
+
+	return cpu;
+}
+
 /*
  * Register accessor functions
  */
@@ -210,19 +220,14 @@
 
 static inline u32 _mpic_cpu_read(struct mpic *mpic, unsigned int reg)
 {
-	unsigned int cpu = 0;
+	unsigned int cpu = mpic_processor_id(mpic);
 
-	if (mpic->flags & MPIC_PRIMARY)
-		cpu = hard_smp_processor_id();
 	return _mpic_read(mpic->reg_type, &mpic->cpuregs[cpu], reg);
 }
 
 static inline void _mpic_cpu_write(struct mpic *mpic, unsigned int reg, u32 value)
 {
-	unsigned int cpu = 0;
-
-	if (mpic->flags & MPIC_PRIMARY)
-		cpu = hard_smp_processor_id();
+	unsigned int cpu = mpic_processor_id(mpic);
 
 	_mpic_write(mpic->reg_type, &mpic->cpuregs[cpu], reg, value);
 }
@@ -913,6 +918,20 @@
 	mpic_irq_write(src, MPIC_INFO(IRQ_VECTOR_PRI), vecpri);
 }
 
+void mpic_set_destination(unsigned int virq, unsigned int cpuid)
+{
+	struct mpic *mpic = mpic_from_irq(virq);
+	unsigned int src = mpic_irq_to_hw(virq);
+
+	DBG("mpic: set_destination(mpic:@%p,virq:%d,src:%d,cpuid:0x%x)\n",
+	    mpic, virq, src, cpuid);
+
+	if (src >= mpic->irq_count)
+		return;
+
+	mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION), 1 << cpuid);
+}
+
 static struct irq_chip mpic_irq_chip = {
 	.irq_mask	= mpic_mask_irq,
 	.irq_unmask	= mpic_unmask_irq,
@@ -993,6 +1012,16 @@
 	/* Set default irq type */
 	set_irq_type(virq, IRQ_TYPE_NONE);
 
+	/* If the MPIC was reset, then all vectors have already been
+	 * initialized.  Otherwise, a per source lazy initialization
+	 * is done here.
+	 */
+	if (!mpic_is_ipi(mpic, hw) && (mpic->flags & MPIC_NO_RESET)) {
+		mpic_set_vector(virq, hw);
+		mpic_set_destination(virq, mpic_processor_id(mpic));
+		mpic_irq_set_priority(virq, 8);
+	}
+
 	return 0;
 }
 
@@ -1040,6 +1069,11 @@
 	.xlate = mpic_host_xlate,
 };
 
+static int mpic_reset_prohibited(struct device_node *node)
+{
+	return node && of_get_property(node, "pic-no-reset", NULL);
+}
+
 /*
  * Exported functions
  */
@@ -1160,7 +1194,15 @@
 	mpic_map(mpic, node, paddr, &mpic->tmregs, MPIC_INFO(TIMER_BASE), 0x1000);
 
 	/* Reset */
-	if (flags & MPIC_WANTS_RESET) {
+
+	/* When using a device-node, reset requests are only honored if the MPIC
+	 * is allowed to reset.
+	 */
+	if (mpic_reset_prohibited(node))
+		mpic->flags |= MPIC_NO_RESET;
+
+	if ((flags & MPIC_WANTS_RESET) && !(mpic->flags & MPIC_NO_RESET)) {
+		printk(KERN_DEBUG "mpic: Resetting\n");
 		mpic_write(mpic->gregs, MPIC_INFO(GREG_GLOBAL_CONF_0),
 			   mpic_read(mpic->gregs, MPIC_INFO(GREG_GLOBAL_CONF_0))
 			   | MPIC_GREG_GCONF_RESET);
@@ -1320,22 +1362,21 @@
 
 	mpic_pasemi_msi_init(mpic);
 
-	if (mpic->flags & MPIC_PRIMARY)
-		cpu = hard_smp_processor_id();
-	else
-		cpu = 0;
+	cpu = mpic_processor_id(mpic);
 
-	for (i = 0; i < mpic->num_sources; i++) {
-		/* start with vector = source number, and masked */
-		u32 vecpri = MPIC_VECPRI_MASK | i |
-			(8 << MPIC_VECPRI_PRIORITY_SHIFT);
+	if (!(mpic->flags & MPIC_NO_RESET)) {
+		for (i = 0; i < mpic->num_sources; i++) {
+			/* start with vector = source number, and masked */
+			u32 vecpri = MPIC_VECPRI_MASK | i |
+				(8 << MPIC_VECPRI_PRIORITY_SHIFT);
 		
-		/* check if protected */
-		if (mpic->protected && test_bit(i, mpic->protected))
-			continue;
-		/* init hw */
-		mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI), vecpri);
-		mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION), 1 << cpu);
+			/* check if protected */
+			if (mpic->protected && test_bit(i, mpic->protected))
+				continue;
+			/* init hw */
+			mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI), vecpri);
+			mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION), 1 << cpu);
+		}
 	}
 	
 	/* Init spurious vector */