diff --git a/sys/arch/sparc/include/types.h b/sys/arch/sparc/include/types.h
index 9a1146934ece..e280f2866bfc 100644
--- a/sys/arch/sparc/include/types.h
+++ b/sys/arch/sparc/include/types.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: types.h,v 1.61 2011/07/30 19:29:12 martin Exp $ */
+/*	$NetBSD: types.h,v 1.62 2012/11/02 00:01:19 chs Exp $ */
 
 /*
  * Copyright (c) 1992, 1993
@@ -122,15 +122,13 @@ typedef	volatile unsigned char		__cpu_simple_lock_t;
 #define	__GENERIC_SOFT_INTERRUPTS_ALL_LEVELS
 #define __HAVE_CPU_DATA_FIRST
 #define	__HAVE_CPU_VMSPACE_EXEC
+#define	__HAVE_RAS
 
 #ifdef SUN4U
 #define	__HAVE_DEVICE_REGISTER_POSTCONFIG
 #define	__HAVE_ATOMIC64_OPS
 #define	__HAVE_CPU_COUNTER	/* sparc v9 CPUs have %tick */
 #define	__HAVE_FAST_SOFTINTS
-#if defined(_KERNEL)
-#define	__HAVE_RAS
-#endif
 #else
 #define	__HAVE_MM_MD_READWRITE
 #endif
diff --git a/sys/arch/sparc/sparc/genassym.cf b/sys/arch/sparc/sparc/genassym.cf
index 0d727c15cf31..13fa2d77ff6e 100644
--- a/sys/arch/sparc/sparc/genassym.cf
+++ b/sys/arch/sparc/sparc/genassym.cf
@@ -1,4 +1,4 @@
-#	$NetBSD: genassym.cf,v 1.67 2011/08/15 02:19:44 mrg Exp $
+#	$NetBSD: genassym.cf,v 1.68 2012/11/02 00:01:19 chs Exp $
 
 #
 # Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -106,18 +106,23 @@ include <sparc/dev/fdvar.h>
 define	BSD		BSD
 define	USRSTACK	USRSTACK
 
-# proc fields and values
+# LWP fields and values
 define	L_PCB		offsetof(struct lwp, l_addr)
 define	L_PROC		offsetof(struct lwp, l_proc)
 define	L_STAT		offsetof(struct lwp, l_stat)
 define	L_WCHAN		offsetof(struct lwp, l_wchan)
 define	L_CPU		offsetof(struct lwp, l_cpu)
 define	L_PRIORITY	offsetof(struct lwp, l_priority)
-define	P_VMSPACE	offsetof(struct proc, p_vmspace)
-define	P_MD_SYSCALL	offsetof(struct proc, p_md.md_syscall)
+define	L_TF		offsetof(struct lwp, l_md.md_tf)
+
 define	LSRUN		LSRUN
 define	LSONPROC	LSONPROC
 
+# proc fields
+define	P_VMSPACE	offsetof(struct proc, p_vmspace)
+define	P_RASLIST	offsetof(struct proc, p_raslist)
+define	P_MD_SYSCALL	offsetof(struct proc, p_md.md_syscall)
+
 # VM structure fields
 define	VM_PMAP		offsetof(struct vmspace, vm_map.pmap)
 define	PMAP_CTX	offsetof(struct pmap, pm_ctx)
@@ -219,6 +224,10 @@ define	PCB_PC		offsetof(struct pcb, pcb_pc)
 define	PCB_UW		offsetof(struct pcb, pcb_uw)
 define	PCB_WIM		offsetof(struct pcb, pcb_wim)
 
+# trapframe fields
+define	TF_PC		offsetof(struct trapframe, tf_pc)
+define	TF_NPC		offsetof(struct trapframe, tf_npc)
+
 # interrupt enable register PTE
 define	IE_REG_PTE_PG	(PG_V | PG_W | PG_S | PG_NC | PG_OBIO)
 
diff --git a/sys/arch/sparc/sparc/locore.s b/sys/arch/sparc/sparc/locore.s
index f89092f235f6..9ba470b5934f 100644
--- a/sys/arch/sparc/sparc/locore.s
+++ b/sys/arch/sparc/sparc/locore.s
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.s,v 1.266 2012/02/19 21:06:28 rmind Exp $	*/
+/*	$NetBSD: locore.s,v 1.267 2012/11/02 00:01:19 chs Exp $	*/
 
 /*
  * Copyright (c) 1996 Paul Kranenburg
@@ -4949,8 +4949,27 @@ Lnosaveoldlwp:
 	st	%o0, [%o4 + PMAP_CPUSET]
 #endif
 
+	/*
+	 * Check for restartable atomic sequences (RAS)
+	 */
+	ld	[%g3 + L_PROC], %o0	! now %o0 points to p
+	ld	[%o0 + P_RASLIST], %o1	! any RAS in p?
+	cmp	%o1, 0
+	be	Lsw_noras		! no, skip RAS check
+	 mov	%g1, %i0		! restore oldlwp (for return value)
+	ld	[%g3 + L_TF], %l3	! pointer to trap frame
+	call	_C_LABEL(ras_lookup)
+	 ld	[%l3 + TF_PC], %o1
+	cmp	%o0, -1
+	be	Lsw_noras
+	 add	%o0, 4, %o1
+	st	%o0, [%l3 + TF_PC]	! store rewound %pc
+	st	%o1, [%l3 + TF_NPC]	! and %npc
+
+Lsw_noras:
+
 	ret
-	 restore %g0, %g1, %o0		! return (lastproc)
+	 restore			! return (oldlwp)
 
 /*
  * Call the idlespin() function if it exists, otherwise just return.
diff --git a/sys/arch/sparc/sparc/machdep.c b/sys/arch/sparc/sparc/machdep.c
index 300c852fdf90..72b25a8345f7 100644
--- a/sys/arch/sparc/sparc/machdep.c
+++ b/sys/arch/sparc/sparc/machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: machdep.c,v 1.324 2012/09/13 11:49:16 martin Exp $ */
+/*	$NetBSD: machdep.c,v 1.325 2012/11/02 00:01:20 chs Exp $ */
 
 /*-
  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
@@ -71,7 +71,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.324 2012/09/13 11:49:16 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.325 2012/11/02 00:01:20 chs Exp $");
 
 #include "opt_compat_netbsd.h"
 #include "opt_compat_sunos.h"
@@ -103,6 +103,7 @@ __KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.324 2012/09/13 11:49:16 martin Exp $")
 #include <sys/simplelock.h>
 #include <sys/module.h>
 #include <sys/mutex.h>
+#include <sys/ras.h>
 
 #include <dev/mm.h>
 
@@ -594,6 +595,7 @@ cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
 {
 	struct trapframe *tf = (struct trapframe *)l->l_md.md_tf;
 	__greg_t *r = mcp->__gregs;
+	__greg_t ras_pc;
 #ifdef FPU_CONTEXT
 	__fpregset_t *f = &mcp->__fpregs;
 	struct fpstate *fps = l->l_md.md_fpstate;
@@ -633,6 +635,12 @@ cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
 	r[_REG_O6] = tf->tf_out[6];
 	r[_REG_O7] = tf->tf_out[7];
 
+	if ((ras_pc = (__greg_t)ras_lookup(l->l_proc,
+	    (void *) r[_REG_PC])) != -1) {
+		r[_REG_PC] = ras_pc;
+		r[_REG_nPC] = ras_pc + 4;
+	}
+
 	*flags |= (_UC_CPU|_UC_TLSBASE);
 
 #ifdef FPU_CONTEXT