Commit-ID: 0ae1d994020d75ac065fd42ac4cbf5ac6ce9b255
Gitweb: https://git.kernel.org/tip/0ae1d994020d75ac065fd42ac4cbf5ac6ce9b255
Author: Mark Rutland <mark.rutland@xxxxxxx>
AuthorDate: Thu, 21 Jun 2018 13:13:10 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 21 Jun 2018 14:22:34 +0200
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@xxxxxxx>
Reviewed-by: Will Deacon <will.deacon@xxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Albert Ou <albert@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/20180621121321.4761-8-mark.rutland@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/asm-generic/atomic-instrumented.h | 9 +++++++++
include/linux/atomic.h | 16 ++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index 1f9b2a767d3c..444bf2f9d54d 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -93,11 +93,20 @@ static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
}
#endif
+#ifdef arch_atomic64_fetch_add_unless
+#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
+{
+ kasan_check_write(v, sizeof(*v));
+ return arch_atomic64_fetch_add_unless(v, a, u);
+}
+#else
static __always_inline bool atomic64_add_unless(atomic64_t *v, s64 a, s64 u)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_add_unless(v, a, u);
}
+#endif
static __always_inline void atomic_inc(atomic_t *v)
{
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
@@ -1042,6 +1042,22 @@ static inline int atomic_dec_if_positive(atomic_t *v)
#define atomic64_try_cmpxchg_release atomic64_try_cmpxchg
#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
--
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