PPC32: Make switch_to return the previous task in the `last' argument

arch/ppc/kernel/process.c

@@ -197,10 +197,12 @@ dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
 	return 1;
 }
 
-void __switch_to(struct task_struct *prev, struct task_struct *new)
+struct task_struct *__switch_to(struct task_struct *prev,
+	struct task_struct *new)
 {
 	struct thread_struct *new_thread, *old_thread;
 	unsigned long s;
+	struct task_struct *last;
 	
 	local_irq_save(s);
 #if CHECK_STACK
@@ -244,8 +246,9 @@ void __switch_to(struct task_struct *prev, struct task_struct *new)
 		new->thread.regs->msr |= MSR_VEC;
 	new_thread = &new->thread;
 	old_thread = &current->thread;
-	_switch(old_thread, new_thread);
+	last = _switch(old_thread, new_thread);
 	local_irq_restore(s);
+	return last;
 }
 
 void show_regs(struct pt_regs * regs)

include/asm-ppc/system.h

@@ -86,8 +86,9 @@ struct device_node;
 extern void note_scsi_host(struct device_node *, void *);
 
 struct task_struct;
-extern void __switch_to(struct task_struct *, struct task_struct *);
-#define switch_to(prev, next, last)	__switch_to((prev), (next))
+extern struct task_struct *__switch_to(struct task_struct *,
+	struct task_struct *);
+#define switch_to(prev, next, last)	((last) = __switch_to((prev), (next)))
 
 struct thread_struct;
 extern struct task_struct *_switch(struct thread_struct *prev,