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>
diff --git a/include/asm-sparc64/ptrace.h b/include/asm-sparc64/ptrace.h
index b4b951d..714b819 100644
--- a/include/asm-sparc64/ptrace.h
+++ b/include/asm-sparc64/ptrace.h
@@ -1,4 +1,3 @@
-/* $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 @@
 	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;