sparc64: Clean up handling of pt_regs trap type encoding.

If we use this from more than one place, it's better to
have helpers instead of twiddling magic constants all
over.

Add pt_regs_trap_type(), pt_regs_clear_trap_type(), and
pt_regs_is_syscall().

Use them in do_signal().
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/signal.c

@@ -513,11 +513,10 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 	struct k_sigaction ka;
 	sigset_t *oldset;
 	siginfo_t info;
-	int signr, tt;
+	int signr;
 	
-	tt = regs->magic & 0x1ff;
-	if (tt == 0x110 || tt == 0x111 || tt == 0x16d) {
-		regs->magic &= ~0x1ff;
+	if (pt_regs_is_syscall(regs)) {
+		pt_regs_clear_trap_type(regs);
 		cookie.restart_syscall = 1;
 	} else
 		cookie.restart_syscall = 0;

include/asm-sparc64/ptrace.h

-/* $Id: ptrace.h,v 1.14 2002/02/09 19:49:32 davem Exp $ */
 #ifndef _SPARC64_PTRACE_H
 #define _SPARC64_PTRACE_H
 
@@ -8,10 +7,15 @@
  * stack during a system call and basically all traps.
  */
 
+/* This magic value must have the low 9 bits clear,
+ * as that is where we encode the %tt value, see below.
+ */
 #define PT_REGS_MAGIC 0x57ac6c00
 
 #ifndef __ASSEMBLY__
 
+#include <linux/types.h>
+
 struct pt_regs {
 	unsigned long u_regs[16]; /* globals and ins */
 	unsigned long tstate;
@@ -33,6 +37,23 @@ struct pt_regs {
 	unsigned int magic;
 };
 
+static inline int pt_regs_trap_type(struct pt_regs *regs)
+{
+	return regs->magic & 0x1ff;
+}
+
+static inline int pt_regs_clear_trap_type(struct pt_regs *regs)
+{
+	return regs->magic &= ~0x1ff;
+}
+
+static inline bool pt_regs_is_syscall(struct pt_regs *regs)
+{
+	int tt = pt_regs_trap_type(regs);
+
+	return (tt == 0x110 || tt == 0x111 || tt == 0x16d);
+}
+
 struct pt_regs32 {
 	unsigned int psr;
 	unsigned int pc;