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authorMark Rutland <mark.rutland@arm.com>2018-06-21 15:13:10 +0300
committerIngo Molnar <mingo@kernel.org>2018-06-21 15:22:34 +0300
commit0ae1d994020d75ac065fd42ac4cbf5ac6ce9b255 (patch)
treecf2d922b4d55a708fd50f77bd9c08bc4d002bd15 /include/linux/atomic.h
parenteccc2da8c03f316bba202e15af2be4615f461900 (diff)
downloadlinux-0ae1d994020d75ac065fd42ac4cbf5ac6ce9b255.tar.xz
atomics: Prepare for atomic64_fetch_add_unless()
Currently all architectures must implement atomic_fetch_add_unless(), with common code providing atomic_add_unless(). Architectures must also implement atomic64_add_unless() directly, with no corresponding atomic64_fetch_add_unless(). This divergence is unfortunate, and means that the APIs for atomic_t, atomic64_t, and atomic_long_t differ. In preparation for unifying things, with architectures providing atomic64_fetch_add_unless, this patch adds a generic atomic64_add_unless() which will use atomic64_fetch_add_unless(). The instrumented atomics are updated to take this case into account. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Albert Ou <albert@sifive.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Link: https://lore.kernel.org/lkml/20180621121321.4761-8-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/atomic.h')
-rw-r--r--include/linux/atomic.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index b89ba36cab94..3c03de648007 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -1043,6 +1043,22 @@ static inline int atomic_dec_if_positive(atomic_t *v)
#endif /* atomic64_try_cmpxchg */
/**
+ * atomic64_add_unless - add unless the number is already a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, if @v was not already @u.
+ * Returns true if the addition was done.
+ */
+#ifdef atomic64_fetch_add_unless
+static inline bool atomic64_add_unless(atomic64_t *v, long long a, long long u)
+{
+ return atomic64_fetch_add_unless(v, a, u) != u;
+}
+#endif
+
+/**
* atomic64_inc_not_zero - increment unless the number is zero
* @v: pointer of type atomic64_t
*