[POWERPC] Define and use TLF_RESTORE_SIGMASK

Replace TIF_RESTORE_SIGMASK with TLF_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.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

5 files changed, 24 insertions, 15 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0c8614d9875c..3a05e9f93d42 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -668,7 +668,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
         /* Check current_thread_info()->flags */
         rlwinm  r9,r1,0,0,(31-THREAD_SHIFT)
         lwz     r9,TI_FLAGS(r9)
-        andi.   r0,r9,(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NEED_RESCHED)
+        andi.   r0,r9,_TIF_USER_WORK_MASK
         bne     do_work
 
 restore_user:
@@ -925,7 +925,7 @@ recheck:
         lwz     r9,TI_FLAGS(r9)
         andi.   r0,r9,_TIF_NEED_RESCHED
         bne-    do_resched
-        andi.   r0,r9,_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK
+        andi.   r0,r9,_TIF_USER_WORK_MASK
         beq     restore_user
 do_user_signal:                 /* r10 contains MSR_KERNEL here */
         ori     r10,r10,MSR_EE
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index a65a44fbe523..ad55488939c3 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -120,7 +120,7 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
         int ret;
         int is32 = is_32bit_task();
 
-        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+        if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
                 oldset = &current->saved_sigmask;
         else if (!oldset)
                 oldset = &current->blocked;
@@ -131,9 +131,10 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
         check_syscall_restart(regs, &ka, signr > 0);
 
         if (signr <= 0) {
+                struct thread_info *ti = current_thread_info();
                 /* No signal to deliver -- put the saved sigmask back */
-                if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
-                        clear_thread_flag(TIF_RESTORE_SIGMASK);
+                if (ti->local_flags & _TLF_RESTORE_SIGMASK) {
+                        ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
                         sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
                 }
                 return 0;               /* no signals delivered */
@@ -169,10 +170,9 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 
                 /*
                  * A signal was successfully delivered; the saved sigmask is in
-                 * its frame, and we can clear the TIF_RESTORE_SIGMASK flag.
+                 * its frame, and we can clear the TLF_RESTORE_SIGMASK flag.
                  */
-                if (test_thread_flag(TIF_RESTORE_SIGMASK))
-                        clear_thread_flag(TIF_RESTORE_SIGMASK);
+                current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
         }
 
         return ret;
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index ad6943468ee9..4ae16d179803 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -243,7 +243,7 @@ long sys_sigsuspend(old_sigset_t mask)
 
         current->state = TASK_INTERRUPTIBLE;
         schedule();
-        set_thread_flag(TIF_RESTORE_SIGMASK);
+        set_restore_sigmask();
         return -ERESTARTNOHAND;
 }
 
diff --git a/arch/ppc/kernel/entry.S b/arch/ppc/kernel/entry.S
index 5f3a5d068a5c..fcd830a292e2 100644
--- a/arch/ppc/kernel/entry.S
+++ b/arch/ppc/kernel/entry.S
@@ -647,7 +647,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
         /* Check current_thread_info()->flags */
         rlwinm  r9,r1,0,0,18
         lwz     r9,TI_FLAGS(r9)
-        andi.   r0,r9,(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NEED_RESCHED)
+        andi.   r0,r9,_TIF_USER_WORK_MASK
         bne     do_work
 
 restore_user:
@@ -898,7 +898,7 @@ recheck:
         lwz     r9,TI_FLAGS(r9)
         andi.   r0,r9,_TIF_NEED_RESCHED
         bne-    do_resched
-        andi.   r0,r9,_TIF_SIGPENDING
+        andi.   r0,r9,_TIF_USER_WORK_MASK
         beq     restore_user
 do_user_signal:                 /* r10 contains MSR_KERNEL here */
         ori     r10,r10,MSR_EE
diff --git a/include/asm-powerpc/thread_info.h b/include/asm-powerpc/thread_info.h
index d030f5ce39ad..e079e81051fd 100644
--- a/include/asm-powerpc/thread_info.h
+++ b/include/asm-powerpc/thread_info.h
@@ -116,7 +116,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SECCOMP             10      /* secure computing */
 #define TIF_RESTOREALL          11      /* Restore all regs (implies NOERROR) */
 #define TIF_NOERROR             12      /* Force successful syscall return */
-#define TIF_RESTORE_SIGMASK     13      /* Restore signal mask in do_signal */
 #define TIF_FREEZE              14      /* Freezing for suspend */
 #define TIF_RUNLATCH            15      /* Is the runlatch enabled? */
 #define TIF_ABI_PENDING         16      /* 32/64 bit switch needed */
@@ -134,21 +133,31 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SECCOMP            (1<<TIF_SECCOMP)
 #define _TIF_RESTOREALL         (1<<TIF_RESTOREALL)
 #define _TIF_NOERROR            (1<<TIF_NOERROR)
-#define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 #define _TIF_FREEZE             (1<<TIF_FREEZE)
 #define _TIF_RUNLATCH           (1<<TIF_RUNLATCH)
 #define _TIF_ABI_PENDING        (1<<TIF_ABI_PENDING)
 #define _TIF_SYSCALL_T_OR_A     (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
 
-#define _TIF_USER_WORK_MASK     ( _TIF_SIGPENDING | \
-                                 _TIF_NEED_RESCHED | _TIF_RESTORE_SIGMASK)
+#define _TIF_USER_WORK_MASK     (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
 #define _TIF_PERSYSCALL_MASK    (_TIF_RESTOREALL|_TIF_NOERROR)
 
 /* Bits in local_flags */
 /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
 #define TLF_NAPPING             0       /* idle thread enabled NAP mode */
+#define TLF_RESTORE_SIGMASK     1       /* Restore signal mask in do_signal */
 
 #define _TLF_NAPPING            (1 << TLF_NAPPING)
+#define _TLF_RESTORE_SIGMASK    (1 << TLF_RESTORE_SIGMASK)
+
+#ifndef __ASSEMBLY__
+#define HAVE_SET_RESTORE_SIGMASK        1
+static inline void set_restore_sigmask(void)
+{
+        struct thread_info *ti = current_thread_info();
+        ti->local_flags |= _TLF_RESTORE_SIGMASK;
+        set_bit(TIF_SIGPENDING, &ti->flags);
+}
+#endif  /* !__ASSEMBLY__ */
 
 #endif /* __KERNEL__ */