sh: TS_RESTORE_SIGMASK conversion.

Replace TIF_RESTORE_SIGMASK with TS_RESTORE_SIGMASK and define our own
set_restore_sigmask() function.  This saves the costly SMP-safe set_bit
operation, which we do not need for the sigmask flag since TIF_SIGPENDING
always has to be set too.

Based on the x86 and powerpc change.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 22 insertions, 4 deletions

diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index bdeb9d46d17d..23eeed89467a 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -19,6 +19,7 @@ struct thread_info {
         struct task_struct      *task;          /* main task structure */
         struct exec_domain      *exec_domain;   /* execution domain */
         unsigned long           flags;          /* low level flags */
+        __u32                   status;         /* thread synchronous flags */
         __u32                   cpu;
         int                     preempt_count; /* 0 => preemptable, <0 => BUG */
         mm_segment_t            addr_limit;     /* thread address space */
@@ -111,7 +112,6 @@ extern void free_thread_info(struct thread_info *ti);
 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 #define TIF_SIGPENDING          1       /* signal pending */
 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
-#define TIF_RESTORE_SIGMASK     3       /* restore signal mask in do_signal() */
 #define TIF_SINGLESTEP          4       /* singlestepping active */
 #define TIF_SYSCALL_AUDIT       5       /* syscall auditing active */
 #define TIF_SECCOMP             6       /* secure computing */
@@ -125,7 +125,6 @@ extern void free_thread_info(struct thread_info *ti);
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
-#define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
@@ -149,13 +148,32 @@ extern void free_thread_info(struct thread_info *ti);
 /* work to do on any return to u-space */
 #define _TIF_ALLWORK_MASK       (_TIF_SYSCALL_TRACE | _TIF_SIGPENDING      | \
                                  _TIF_NEED_RESCHED  | _TIF_SYSCALL_AUDIT   | \
-                                 _TIF_SINGLESTEP    | _TIF_RESTORE_SIGMASK | \
-                                 _TIF_NOTIFY_RESUME | _TIF_SYSCALL_TRACEPOINT)
+                                 _TIF_SINGLESTEP    | _TIF_NOTIFY_RESUME   | \
+                                 _TIF_SYSCALL_TRACEPOINT)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK          (_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \
                                  _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP))
 
+/*
+ * Thread-synchronous status.
+ *
+ * This is different from the flags in that nobody else
+ * ever touches our thread-synchronous status, so we don't
+ * have to worry about atomic accesses.
+ */
+#define TS_RESTORE_SIGMASK      0x0001  /* restore signal mask in do_signal() */
+
+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK        1
+static inline void set_restore_sigmask(void)
+{
+        struct thread_info *ti = current_thread_info();
+        ti->status |= TS_RESTORE_SIGMASK;
+        set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
+}
+#endif  /* !__ASSEMBLY__ */
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASM_SH_THREAD_INFO_H */