x86/asm/entry/64: Merge the field offset into the THREAD_INFO() macro

Before:

   TI_sysenter_return+THREAD_INFO(%rsp,3*8),%r10d

After:

   movl    THREAD_INFO(TI_sysenter_return, %rsp, 3*8), %r10d

to turn it into a clear thread_info accessor.

No code changed:

 md5:
   fb4cb2b3ce05d89940ca304efc8ff183  ia32entry.o.before.asm
   fb4cb2b3ce05d89940ca304efc8ff183  ia32entry.o.after.asm

   e39f2958a5d1300158e276e4f7663263  entry_64.o.before.asm
   e39f2958a5d1300158e276e4f7663263  entry_64.o.after.asm

Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/20150324184411.GB14760@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/thread_info.h

@@ -222,7 +222,7 @@ static inline unsigned long current_stack_pointer(void)
  * currently at exactly SIZEOF_PTREGS bytes away from the top of the
  * stack:
  *
- *      mov TI_flags+THREAD_INFO(%rsp, SIZEOF_PTREGS), %eax
+ *      mov THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS), %eax
  *
  * will translate to:
  *
@@ -230,7 +230,7 @@ static inline unsigned long current_stack_pointer(void)
  *
  * which is below the current RSP by almost 16K.
  */
-#define THREAD_INFO(reg, off) ((off)-THREAD_SIZE)(reg)
+#define THREAD_INFO(field, reg, off) ((field)+(off)-THREAD_SIZE)(reg)
 
 #endif