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authorPaul E. McKenney <paul.mckenney@linaro.org>2011-05-11 05:33:33 -0700
committerIngo Molnar <mingo@elte.hu>2011-05-28 17:41:46 +0200
commit55c2945aa9d4d907ec5ca4f6a4e30ae908d8d30d (patch)
treee9cb0d05634fe214788dc6c07e2decf69cde98e3 /include/linux
parent29f742f88a32c9ab8cf6d9ba69e1ea918be5aa58 (diff)
atomic: Add atomic_or()
An atomic_or() function is needed by TREE_RCU to avoid deadlock, so add a generic version. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/atomic.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 96c038e43d6..ee456c79b0e 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -34,4 +34,17 @@ static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint)
}
#endif
+#ifndef CONFIG_ARCH_HAS_ATOMIC_OR
+static inline void atomic_or(int i, atomic_t *v)
+{
+ int old;
+ int new;
+
+ do {
+ old = atomic_read(v);
+ new = old | i;
+ } while (atomic_cmpxchg(v, old, new) != old);
+}
+#endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */
+
#endif /* _LINUX_ATOMIC_H */