Sparc64 updates for recent preemption fixes.

arch/sparc64/kernel/entry.S

@@ -1436,7 +1436,9 @@ ret_from_syscall:
 		 * %o7 for us.  Check performance counter stuff too.
 		 */
 		andn		%o7, _TIF_NEWCHILD, %l0
+#if CONFIG_SMP || CONFIG_PREEMPT
 		call		schedule_tail
+#endif
 		 stx		%l0, [%g6 + TI_FLAGS]
 		andcc		%l0, _TIF_PERFCTR, %g0
 		be,pt		%icc, 1f

arch/sparc64/kernel/process.c

@@ -107,10 +107,8 @@ void kpreempt_maybe(void)
 
 	if (local_irq_count(cpu) == 0 &&
 	    local_bh_count(cpu) == 0 &&
-	    test_thread_flag(TIF_NEED_RESCHED)) {
-		current->state = TASK_RUNNING;
+	    test_thread_flag(TIF_NEED_RESCHED))
 		schedule();
-	}
 }
 #endif
 

arch/sparc64/kernel/ptrace.c

@@ -620,11 +620,10 @@ asmlinkage void syscall_trace(void)
 	if (!(current->ptrace & PT_PTRACED))
 		return;
 	current->exit_code = SIGTRAP;
-	preempt_disable();
 	current->state = TASK_STOPPED;
 	notify_parent(current, SIGCHLD);
 	schedule();
-	preempt_enable();
+
 	/*
 	 * this isn't the same as continuing with a signal, but it will do
 	 * for normal use.  strace only continues with a signal if the

arch/sparc64/kernel/rtrap.S

@@ -274,12 +274,12 @@ to_kernel:
 #ifdef CONFIG_PREEMPT
 		ldsw			[%g6 + TI_PRE_COUNT], %l5
 		brnz			%l5, kern_fpucheck
-		 add			%l5, 1, %l6
+		 sethi			%hi(PREEMPT_ACTIVE), %l6
 		stw			%l6, [%g6 + TI_PRE_COUNT]
 		call			kpreempt_maybe
 		 nop
 		ba,pt			%xcc, rtrap
-		 stw			%l5, [%g6 + TI_PRE_COUNT]
+		 stw			%g0, [%g6 + TI_PRE_COUNT]
 #endif
 kern_fpucheck:	ldub			[%g6 + TI_FPDEPTH], %l5
 		brz,pt			%l5, rt_continue

arch/sparc64/kernel/signal.c

@@ -713,11 +713,9 @@ static int do_signal(sigset_t *oldset, struct pt_regs * regs,
 
 		if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
 			current->exit_code = signr;
-			preempt_disable();
 			current->state = TASK_STOPPED;
 			notify_parent(current, SIGCHLD);
 			schedule();
-			preempt_enable();
 			if (!(signr = current->exit_code))
 				continue;
 			current->exit_code = 0;
@@ -771,15 +769,13 @@ static int do_signal(sigset_t *oldset, struct pt_regs * regs,
 			case SIGSTOP: {
 				struct signal_struct *sig;
 
+				current->state = TASK_STOPPED;
 				current->exit_code = signr;
 				sig = current->parent->sig;
-				preempt_disable();
-				current->state = TASK_STOPPED;
 				if (sig && !(sig->action[SIGCHLD-1].sa.sa_flags &
 				      SA_NOCLDSTOP))
 					notify_parent(current, SIGCHLD);
 				schedule();
-				preempt_enable();
 				continue;
 			}
 

arch/sparc64/kernel/signal32.c

@@ -1387,11 +1387,9 @@ int do_signal32(sigset_t *oldset, struct pt_regs * regs,
 
 		if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
 			current->exit_code = signr;
-			preempt_disable();
 			current->state = TASK_STOPPED;
 			notify_parent(current, SIGCHLD);
 			schedule();
-			preempt_enable();
 			if (!(signr = current->exit_code))
 				continue;
 			current->exit_code = 0;
@@ -1445,15 +1443,13 @@ int do_signal32(sigset_t *oldset, struct pt_regs * regs,
 			case SIGSTOP: {
 				struct signal_struct *sig;
 
+				current->state = TASK_STOPPED;
 				current->exit_code = signr;
 				sig = current->parent->sig;
-				preempt_disable();
-				current->state = TASK_STOPPED;
 				if (sig && !(sig->action[SIGCHLD-1].sa.sa_flags &
 				      SA_NOCLDSTOP))
 					notify_parent(current, SIGCHLD);
 				schedule();
-				preempt_enable();
 				continue;
 			}
 			case SIGQUIT: case SIGILL: case SIGTRAP:

include/asm-sparc64/thread_info.h

@@ -109,6 +109,8 @@ struct thread_info {
 #define THREAD_SHIFT PAGE_SHIFT
 #endif /* PAGE_SHIFT == 13 */
 
+#define PREEMPT_ACTIVE		0x4000000
+
 /*
  * macros/functions for gaining access to the thread information structure
  */