diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index bc428b5f126c18b48d5b52e502d39eaf6241ac84..a4787197d8fe3ea39b28c646ecfed383263ea0f1 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -16,6 +16,7 @@ config OPENRISC
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IOMAP
 	select GENERIC_CPU_DEVICES
+	select GENERIC_ATOMIC64
 
 config MMU
 	def_bool y
diff --git a/arch/openrisc/include/asm/page.h b/arch/openrisc/include/asm/page.h
index b041b344b229e6329396b46dce1e13f02599b899..108906f991d6766c7ec9d9dd94e3ab3da1aec07c 100644
--- a/arch/openrisc/include/asm/page.h
+++ b/arch/openrisc/include/asm/page.h
@@ -71,9 +71,6 @@ typedef struct page *pgtable_t;
 #define __pgd(x)	((pgd_t) { (x) })
 #define __pgprot(x)	((pgprot_t) { (x) })
 
-extern unsigned long memory_start;
-extern unsigned long memory_end;
-
 #endif /* !__ASSEMBLY__ */
 
 
@@ -94,8 +91,7 @@ extern unsigned long memory_end;
 
 #define pfn_valid(pfn)          ((pfn) < max_mapnr)
 
-#define virt_addr_valid(kaddr)  (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
-				((void *)(kaddr) < (void *)memory_end))
+#define virt_addr_valid(kaddr)	(pfn_valid(virt_to_pfn(kaddr)))
 
 #endif /* __ASSEMBLY__ */
 
diff --git a/arch/openrisc/include/asm/processor.h b/arch/openrisc/include/asm/processor.h
index bb54c97b9783cd0feed94534e3f493c27c8b70fe..f7516fa78b58a2e2311433f63a1a401d7de9d044 100644
--- a/arch/openrisc/include/asm/processor.h
+++ b/arch/openrisc/include/asm/processor.h
@@ -81,8 +81,8 @@ extern inline void prepare_to_copy(struct task_struct *tsk)
 #define INIT_THREAD  { }
 
 
-#define KSTK_EIP(tsk)   (task_pt_regs(tsk)->pc);
-#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp);
+#define KSTK_EIP(tsk)   (task_pt_regs(tsk)->pc)
+#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
 
 
 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
diff --git a/arch/openrisc/include/asm/ptrace.h b/arch/openrisc/include/asm/ptrace.h
index e612ce4512c73db468d6597673d87fa729b24226..4651a737591d5a12f4ca04b260da8bbf78783e28 100644
--- a/arch/openrisc/include/asm/ptrace.h
+++ b/arch/openrisc/include/asm/ptrace.h
@@ -73,9 +73,13 @@ struct pt_regs {
 		};
 	};
 	long  pc;
+	/* For restarting system calls:
+	 * Set to syscall number for syscall exceptions,
+	 * -1 for all other exceptions.
+	 */
 	long  orig_gpr11;	/* For restarting system calls */
-	long  syscallno;	/* Syscall number (used by strace) */
 	long dummy;		/* Cheap alignment fix */
+	long dummy2;		/* Cheap alignment fix */
 };
 
 /* TODO: Rename this to REDZONE because that's what it is */
diff --git a/arch/openrisc/include/asm/syscall.h b/arch/openrisc/include/asm/syscall.h
index 9f0337055d26f4b407f29c2ab2f34ed3930fb6e9..b752bb67891db2da9358abc3af1bc1f8b95c57cc 100644
--- a/arch/openrisc/include/asm/syscall.h
+++ b/arch/openrisc/include/asm/syscall.h
@@ -25,7 +25,7 @@
 static inline int
 syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
 {
-	return regs->syscallno ? regs->syscallno : -1;
+	return regs->orig_gpr11;
 }
 
 static inline void
@@ -50,10 +50,7 @@ static inline void
 syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
 			 int error, long val)
 {
-	if (error)
-		regs->gpr[11] = -error;
-	else
-		regs->gpr[11] = val;
+	regs->gpr[11] = (long) error ?: val;
 }
 
 static inline void
diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
index c310e45b538ed21e3973373b97a1352503d9d298..f5abaa0ffc38c407799b17e97595204277ff4fa4 100644
--- a/arch/openrisc/include/asm/uaccess.h
+++ b/arch/openrisc/include/asm/uaccess.h
@@ -26,7 +26,6 @@
 #include <linux/thread_info.h>
 #include <linux/prefetch.h>
 #include <linux/string.h>
-#include <linux/thread_info.h>
 #include <asm/page.h>
 
 #define VERIFY_READ	0
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index d5f9c35a583ff21568dfee733199a8d93475e47e..6e61af8682b8dc010e78da67a38bd40e8af4e5fa 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -95,7 +95,6 @@ handler:							;\
 	/* r1, EPCR, ESR a already saved */			;\
 	l.sw	PT_GPR2(r1),r2					;\
 	l.sw    PT_GPR3(r1),r3					;\
-	l.sw    PT_ORIG_GPR11(r1),r11				;\
 	/* r4 already save */					;\
 	l.sw    PT_GPR5(r1),r5					;\
 	l.sw    PT_GPR6(r1),r6					;\
@@ -125,7 +124,9 @@ handler:							;\
 	/* r30 already save */					;\
 /*        l.sw    PT_GPR30(r1),r30*/					;\
 	l.sw    PT_GPR31(r1),r31					;\
-	l.sw    PT_SYSCALLNO(r1),r0
+	/* Store -1 in orig_gpr11 for non-syscall exceptions */	;\
+	l.addi	r30,r0,-1					;\
+	l.sw	PT_ORIG_GPR11(r1),r30
 
 #define UNHANDLED_EXCEPTION(handler,vector)			\
 	.global	handler						;\
@@ -133,7 +134,6 @@ handler:							;\
 	/* r1, EPCR, ESR already saved */			;\
 	l.sw    PT_GPR2(r1),r2					;\
 	l.sw    PT_GPR3(r1),r3					;\
-	l.sw    PT_ORIG_GPR11(r1),r11				;\
 	l.sw    PT_GPR5(r1),r5					;\
 	l.sw    PT_GPR6(r1),r6					;\
 	l.sw    PT_GPR7(r1),r7					;\
@@ -162,7 +162,9 @@ handler:							;\
 	/* r31 already saved */					;\
 	l.sw    PT_GPR30(r1),r30					;\
 /*        l.sw    PT_GPR31(r1),r31	*/				;\
-	l.sw    PT_SYSCALLNO(r1),r0				;\
+	/* Store -1 in orig_gpr11 for non-syscall exceptions */	;\
+	l.addi	r30,r0,-1					;\
+	l.sw	PT_ORIG_GPR11(r1),r30				;\
 	l.addi	r3,r1,0						;\
 	/* r4 is exception EA */				;\
 	l.addi	r5,r0,vector					;\
@@ -554,6 +556,7 @@ ENTRY(_sys_call_handler)
 	l.sw    PT_GPR9(r1),r9
 	/* r10 already saved */
 	l.sw    PT_GPR11(r1),r11
+	/* orig_gpr11 must be set for syscalls */
 	l.sw    PT_ORIG_GPR11(r1),r11
 	/* r12,r13 already saved */
 
@@ -567,9 +570,6 @@ ENTRY(_sys_call_handler)
 	/* r30 is the only register we clobber in the fast path */
 	/* r30 already saved */
 /*	l.sw    PT_GPR30(r1),r30 */
-	/* This is used by do_signal to determine whether to check for
-	 * syscall restart or not */
-	l.sw    PT_SYSCALLNO(r1),r11
 
 _syscall_check_trace_enter:
 	/* If TIF_SYSCALL_TRACE is set, then we want to do syscall tracing */
@@ -731,7 +731,7 @@ _syscall_trace_enter:
 	 * so that we can do the syscall for real and return to the syscall
 	 * hot path.
 	 */
-	l.lwz	r11,PT_SYSCALLNO(r1)
+	l.lwz	r11,PT_GPR11(r1)
 	l.lwz	r3,PT_GPR3(r1)
 	l.lwz	r4,PT_GPR4(r1)
 	l.lwz	r5,PT_GPR5(r1)
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
index c75018d2264429f7428e40d8dfd2510f36cef3aa..1088b5fca3bdd44abed7ec4432dc135e918856f8 100644
--- a/arch/openrisc/kernel/head.S
+++ b/arch/openrisc/kernel/head.S
@@ -26,6 +26,7 @@
 #include <asm/cache.h>
 #include <asm/spr_defs.h>
 #include <asm/asm-offsets.h>
+#include <linux/of_fdt.h>
 
 #define tophys(rd,rs)				\
 	l.movhi	rd,hi(-KERNELBASE)		;\
@@ -440,6 +441,9 @@ _dispatch_do_ipage_fault:
 	__HEAD
 	.global _start
 _start:
+	/* save kernel parameters */
+	l.or	r25,r0,r3	/* pointer to fdt */
+
 	/*
 	 * ensure a deterministic start
 	 */
@@ -471,7 +475,6 @@ _start:
 	CLEAR_GPR(r22)
 	CLEAR_GPR(r23)
 	CLEAR_GPR(r24)
-	CLEAR_GPR(r25)
 	CLEAR_GPR(r26)
 	CLEAR_GPR(r27)
 	CLEAR_GPR(r28)
@@ -565,6 +568,18 @@ enable_mmu:
 	// reset the simulation counters
 	l.nop 5
 
+	/* check fdt header magic word */
+	l.lwz	r3,0(r25)	/* load magic from fdt into r3 */
+	l.movhi	r4,hi(OF_DT_HEADER)
+	l.ori	r4,r4,lo(OF_DT_HEADER)
+	l.sfeq	r3,r4
+	l.bf	_fdt_found
+	 l.nop
+	/* magic number mismatch, set fdt pointer to null */
+	l.or	r25,r0,r0
+_fdt_found:
+	/* pass fdt pointer to or32_early_setup in r3 */
+	l.or	r3,r0,r25
 	LOAD_SYMBOL_2_GPR(r24, or32_early_setup)
 	l.jalr r24
 	 l.nop
diff --git a/arch/openrisc/kernel/ptrace.c b/arch/openrisc/kernel/ptrace.c
index 7259047d5f9dbd21cc8529119dfc21f61cd2b840..6deacb6b95a454b5496f0d4e37c6d8b4fac74c45 100644
--- a/arch/openrisc/kernel/ptrace.c
+++ b/arch/openrisc/kernel/ptrace.c
@@ -188,11 +188,11 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 		 */
 		ret = -1L;
 
-	audit_syscall_entry(audit_arch(), regs->syscallno,
+	audit_syscall_entry(audit_arch(), regs->gpr[11],
 			    regs->gpr[3], regs->gpr[4],
 			    regs->gpr[5], regs->gpr[6]);
 
-	return ret ? : regs->syscallno;
+	return ret ? : regs->gpr[11];
 }
 
 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
diff --git a/arch/openrisc/kernel/setup.c b/arch/openrisc/kernel/setup.c
index 1422f747f52bed163ea2aab449c919656228a813..bf5eba22ce9e1b6503c01c311362fe9e3fd0756b 100644
--- a/arch/openrisc/kernel/setup.c
+++ b/arch/openrisc/kernel/setup.c
@@ -207,18 +207,18 @@ void __init setup_cpuinfo(void)
  * Handles the pointer to the device tree that this kernel is to use
  * for establishing the available platform devices.
  *
- * For now, this is limited to using the built-in device tree.  In the future,
- * it is intended that this function will take a pointer to the device tree
- * that is potentially built-in, but potentially also passed in by the
- * bootloader, or discovered by some equally clever means...
+ * Falls back on built-in device tree in case null pointer is passed.
  */
 
-void __init or32_early_setup(void)
+void __init or32_early_setup(unsigned int fdt)
 {
-
-	early_init_devtree(__dtb_start);
-
-	printk(KERN_INFO "Compiled-in FDT at 0x%p\n", __dtb_start);
+	if (fdt) {
+		early_init_devtree((void*) fdt);
+		printk(KERN_INFO "FDT at 0x%08x\n", fdt);
+	} else {
+		early_init_devtree(__dtb_start);
+		printk(KERN_INFO "Compiled-in FDT at %p\n", __dtb_start);
+	}
 }
 
 static int __init openrisc_device_probe(void)
diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c
index 95207ab0c99ed536016e88b8be1a2b077ec3bae5..e970743251ae3c922fb4ff4f9722f4dc596f1f6f 100644
--- a/arch/openrisc/kernel/signal.c
+++ b/arch/openrisc/kernel/signal.c
@@ -102,10 +102,7 @@ asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
 		goto badframe;
 
 	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(&set);
 
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
 		goto badframe;
@@ -189,8 +186,8 @@ static inline void __user *get_sigframe(struct k_sigaction *ka,
  * trampoline which performs the syscall sigreturn, or a provided
  * user-mode trampoline.
  */
-static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
-			   sigset_t *set, struct pt_regs *regs)
+static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+			  sigset_t *set, struct pt_regs *regs)
 {
 	struct rt_sigframe *frame;
 	unsigned long return_ip;
@@ -247,31 +244,27 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	/* actually move the usp to reflect the stacked frame */
 	regs->sp = (unsigned long)frame;
 
-	return;
+	return 0;
 
 give_sigsegv:
-	if (sig == SIGSEGV)
-		ka->sa.sa_handler = SIG_DFL;
-	force_sig(SIGSEGV, current);
+	force_sigsegv(sig, current);
+	return -EFAULT;
 }
 
-static inline void
+static inline int
 handle_signal(unsigned long sig,
 	      siginfo_t *info, struct k_sigaction *ka,
 	      sigset_t *oldset, struct pt_regs *regs)
 {
-	setup_rt_frame(sig, ka, info, oldset, regs);
+	int ret;
 
-	if (ka->sa.sa_flags & SA_ONESHOT)
-		ka->sa.sa_handler = SIG_DFL;
+	ret = setup_rt_frame(sig, ka, info, oldset, regs);
+	if (ret)
+		return ret;
 
-	spin_lock_irq(&current->sighand->siglock);
-	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
-	if (!(ka->sa.sa_flags & SA_NODEFER))
-		sigaddset(&current->blocked, sig);
-	recalc_sigpending();
+	block_sigmask(ka, sig);
 
-	spin_unlock_irq(&current->sighand->siglock);
+	return 0;
 }
 
 /*
@@ -312,7 +305,7 @@ void do_signal(struct pt_regs *regs)
 	 * below mean that the syscall executed to completion and no
 	 * restart is necessary.
 	 */
-	if (regs->syscallno) {
+	if (regs->orig_gpr11) {
 		int restart = 0;
 
 		switch (regs->gpr[11]) {
@@ -360,13 +353,13 @@ void do_signal(struct pt_regs *regs)
 			oldset = &current->blocked;
 
 		/* Whee!  Actually deliver the signal.  */
-		handle_signal(signr, &info, &ka, oldset, regs);
-		/* a signal was successfully delivered; the saved
-		 * sigmask will have been stored in the signal frame,
-		 * and will be restored by sigreturn, so we can simply
-		 * clear the TIF_RESTORE_SIGMASK flag */
-		if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		if (!handle_signal(signr, &info, &ka, oldset, regs)) {
+			/* a signal was successfully delivered; the saved
+			 * sigmask will have been stored in the signal frame,
+			 * and will be restored by sigreturn, so we can simply
+			 * clear the TIF_RESTORE_SIGMASK flag */
 			clear_thread_flag(TIF_RESTORE_SIGMASK);
+		}
 
 		tracehook_signal_handler(signr, &info, &ka, regs,
 					 test_thread_flag(TIF_SINGLESTEP));
diff --git a/arch/openrisc/kernel/time.c b/arch/openrisc/kernel/time.c
index bd946ef1623d6fdb10c5d1d0588085ce7f1cdae5..7c52e9494a8de02f589f88586187bafa0d1688d1 100644
--- a/arch/openrisc/kernel/time.c
+++ b/arch/openrisc/kernel/time.c
@@ -125,16 +125,13 @@ irqreturn_t __irq_entry timer_interrupt(struct pt_regs *regs)
 
 static __init void openrisc_clockevent_init(void)
 {
-	clockevents_calc_mult_shift(&clockevent_openrisc_timer,
-				    cpuinfo.clock_frequency, 4);
+	clockevent_openrisc_timer.cpumask = cpumask_of(0);
 
 	/* We only have 28 bits */
-	clockevent_openrisc_timer.max_delta_ns =
-	    clockevent_delta2ns((u32) 0x0fffffff, &clockevent_openrisc_timer);
-	clockevent_openrisc_timer.min_delta_ns =
-	    clockevent_delta2ns(1, &clockevent_openrisc_timer);
-	clockevent_openrisc_timer.cpumask = cpumask_of(0);
-	clockevents_register_device(&clockevent_openrisc_timer);
+	clockevents_config_and_register(&clockevent_openrisc_timer,
+					cpuinfo.clock_frequency,
+					100, 0x0fffffff);
+
 }
 
 /**
diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c
index a4ec44a052b23403fdb716d9f1f6a682c12b46df..a2ee12948f4056d9f6d50a4e03b42818569f949c 100644
--- a/arch/openrisc/kernel/traps.c
+++ b/arch/openrisc/kernel/traps.c
@@ -115,6 +115,7 @@ void dump_stack(void)
 
 	show_stack(current, &stack);
 }
+EXPORT_SYMBOL(dump_stack);
 
 void show_registers(struct pt_regs *regs)
 {
@@ -145,8 +146,8 @@ void show_registers(struct pt_regs *regs)
 	       regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
 	printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
 	       regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
-	printk("  RES: %08lx oGPR11: %08lx syscallno: %08lx\n",
-	       regs->gpr[11], regs->orig_gpr11, regs->syscallno);
+	printk("  RES: %08lx oGPR11: %08lx\n",
+	       regs->gpr[11], regs->orig_gpr11);
 
 	printk("Process %s (pid: %d, stackpage=%08lx)\n",
 	       current->comm, current->pid, (unsigned long)current);
@@ -207,8 +208,8 @@ void nommu_dump_state(struct pt_regs *regs,
 	       regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
 	printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
 	       regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
-	printk("  RES: %08lx oGPR11: %08lx syscallno: %08lx\n",
-	       regs->gpr[11], regs->orig_gpr11, regs->syscallno);
+	printk("  RES: %08lx oGPR11: %08lx\n",
+	       regs->gpr[11], regs->orig_gpr11);
 
 	printk("Process %s (pid: %d, stackpage=%08lx)\n",
 	       ((struct task_struct *)(__pa(current)))->comm,
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index 359dcb20fe85770b00f920b81eb047eaff1c243f..736f6b2f30af3ffa528131c64ebdcda521b7405e 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -222,8 +222,7 @@ void __init mem_init(void)
 {
 	int codesize, reservedpages, datasize, initsize;
 
-	if (!mem_map)
-		BUG();
+	BUG_ON(!mem_map);
 
 	set_max_mapnr_init();