atomic: Export fetch_or()

Export fetch_or() that's implemented and used internally by the
scheduler. We are going to use it for NO_HZ so make it generally
available.

Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 301de78d65f75c194720cc5168359dbce6eab59f..6c502cb13c95aa2f93466687c16d23b950b231d6 100644 (file)
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -548,6 +548,27 @@ static inline int atomic_dec_if_positive(atomic_t *v)
 }
 #endif
 
+/**
+ * fetch_or - perform *ptr |= mask and return old value of *ptr
+ * @ptr: pointer to value
+ * @mask: mask to OR on the value
+ *
+ * cmpxchg based fetch_or, macro so it works for different integer types
+ */
+#ifndef fetch_or
+#define fetch_or(ptr, mask)                                            \
+({     typeof(*(ptr)) __old, __val = *(ptr);                           \
+       for (;;) {                                                      \
+               __old = cmpxchg((ptr), __val, __val | (mask));          \
+               if (__old == __val)                                     \
+                       break;                                          \
+               __val = __old;                                          \
+       }                                                               \
+       __old;                                                          \
+})
+#endif
+
+
 #ifdef CONFIG_GENERIC_ATOMIC64
 #include <asm-generic/atomic64.h>
 #endif

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9503d590e5ef5b81537947b9925ecfe689f72a91..7142feb4b92ddef23536173fb443ca433bfa3b79 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -453,20 +453,6 @@ static inline void init_hrtick(void)
 }
 #endif /* CONFIG_SCHED_HRTICK */
 
-/*
- * cmpxchg based fetch_or, macro so it works for different integer types
- */
-#define fetch_or(ptr, val)                                             \
-({     typeof(*(ptr)) __old, __val = *(ptr);                           \
-       for (;;) {                                                      \
-               __old = cmpxchg((ptr), __val, __val | (val));           \
-               if (__old == __val)                                     \
-                       break;                                          \
-               __val = __old;                                          \
-       }                                                               \
-       __old;                                                          \
-})
-
 #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
 /*
  * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,