[PATCHv2 03/16] atomics/treewide: make atomic64_inc_not_zero() optional

From: Mark Rutland
Date: Tue May 29 2018 - 11:48:13 EST

We define a trivial fallback for atomic_inc_not_zero(), but don't do
the same for atmic64_inc_not_zero(), leading most architectures to
define the same boilerplate.

Let's add a fallback in <linux/atomic.h>, and remove the redundant
implementations. Note that atomic64_add_unless() is always defined in
<linux/atomic.h>, and promotes its arguments to the requisite types, so
we need not do this explicitly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
---
arch/alpha/include/asm/atomic.h | 2 --
arch/arc/include/asm/atomic.h | 1 -
arch/arm/include/asm/atomic.h | 1 -
arch/arm64/include/asm/atomic.h | 2 --
arch/ia64/include/asm/atomic.h | 2 --
arch/mips/include/asm/atomic.h | 2 --
arch/parisc/include/asm/atomic.h | 2 --
arch/powerpc/include/asm/atomic.h | 1 +
arch/riscv/include/asm/atomic.h | 7 -------
arch/s390/include/asm/atomic.h | 1 -
arch/sparc/include/asm/atomic_64.h | 2 --
arch/x86/include/asm/atomic64_32.h | 2 +-
arch/x86/include/asm/atomic64_64.h | 2 --
include/asm-generic/atomic-instrumented.h | 3 +++
include/asm-generic/atomic64.h | 1 -
include/linux/atomic.h | 11 +++++++++++
16 files changed, 16 insertions(+), 26 deletions(-)

diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
index 392b15a4dd4f..eb0f25e4c5dd 100644
--- a/arch/alpha/include/asm/atomic.h
+++ b/arch/alpha/include/asm/atomic.h
@@ -296,8 +296,6 @@ static inline long atomic64_dec_if_positive(atomic64_t *v)
return old - 1;
}

-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)

diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index cecdf3403caf..1406825b5e7d 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -603,7 +603,6 @@ static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
#define atomic64_dec(v) atomic64_sub(1LL, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)

#endif /* !CONFIG_GENERIC_ATOMIC64 */

diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index 9d56d0727c9b..02f3894faa48 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -534,7 +534,6 @@ static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
#define atomic64_dec(v) atomic64_sub(1LL, (v))
#define atomic64_dec_return_relaxed(v) atomic64_sub_return_relaxed(1LL, (v))
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)

#endif /* !CONFIG_GENERIC_ATOMIC64 */
#endif
diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h
index 264d20339f74..ad50412889c5 100644
--- a/arch/arm64/include/asm/atomic.h
+++ b/arch/arm64/include/asm/atomic.h
@@ -204,7 +204,5 @@
#define atomic64_add_unless(v, a, u) (___atomic_add_unless(v, a, u, 64) != u)
#define atomic64_andnot atomic64_andnot

-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
#endif
#endif
diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h
index 9d2ddde5f9d5..93d48b823220 100644
--- a/arch/ia64/include/asm/atomic.h
+++ b/arch/ia64/include/asm/atomic.h
@@ -246,8 +246,6 @@ static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u)
return c != (u);
}

-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
{
long c, old, dec;
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index 02fc1553cf9b..502e691c6393 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -644,8 +644,6 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
return c != (u);
}

-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))

diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h
index 7748abced766..3fd0243bf405 100644
--- a/arch/parisc/include/asm/atomic.h
+++ b/arch/parisc/include/asm/atomic.h
@@ -305,8 +305,6 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
return c != (u);
}

-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
/*
* atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
diff --git a/arch/powerpc/include/asm/atomic.h b/arch/powerpc/include/asm/atomic.h
index 1483261080a1..e59620ee4f6b 100644
--- a/arch/powerpc/include/asm/atomic.h
+++ b/arch/powerpc/include/asm/atomic.h
@@ -582,6 +582,7 @@ static __inline__ int atomic64_inc_not_zero(atomic64_t *v)

return t1 != 0;
}
+#define atomic64_inc_not_zero(v) atomic64_inc_not_zero((v))

#endif /* __powerpc64__ */

diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
index 0e27e050ba14..18259e90f57e 100644
--- a/arch/riscv/include/asm/atomic.h
+++ b/arch/riscv/include/asm/atomic.h
@@ -375,13 +375,6 @@ static __always_inline int atomic64_add_unless(atomic64_t *v, long a, long u)
}
#endif

-#ifndef CONFIG_GENERIC_ATOMIC64
-static __always_inline long atomic64_inc_not_zero(atomic64_t *v)
-{
- return atomic64_add_unless(v, 1, 0);
-}
-#endif
-
/*
* atomic_{cmp,}xchg is required to have exactly the same ordering semantics as
* {cmp,}xchg and the operations that return, so they need a full barrier.
diff --git a/arch/s390/include/asm/atomic.h b/arch/s390/include/asm/atomic.h
index c2858cdd8c29..66dac30a4fe1 100644
--- a/arch/s390/include/asm/atomic.h
+++ b/arch/s390/include/asm/atomic.h
@@ -212,6 +212,5 @@ static inline long atomic64_dec_if_positive(atomic64_t *v)
#define atomic64_dec(_v) atomic64_sub(1, _v)
#define atomic64_dec_return(_v) atomic64_sub_return(1, _v)
#define atomic64_dec_and_test(_v) (atomic64_sub_return(1, _v) == 0)
-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)

#endif /* __ARCH_S390_ATOMIC__ */
diff --git a/arch/sparc/include/asm/atomic_64.h b/arch/sparc/include/asm/atomic_64.h
index f416fd3d2708..07830a316464 100644
--- a/arch/sparc/include/asm/atomic_64.h
+++ b/arch/sparc/include/asm/atomic_64.h
@@ -123,8 +123,6 @@ static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
return c != (u);
}

-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
long atomic64_dec_if_positive(atomic64_t *v);

#endif /* !(__ARCH_SPARC64_ATOMIC__) */
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index 92212bf0484f..2a33cc17801b 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -295,7 +295,7 @@ static inline int arch_atomic64_add_unless(atomic64_t *v, long long a,
return (int)a;
}

-
+#define arch_atomic64_inc_not_zero arch_atomic64_inc_not_zero
static inline int arch_atomic64_inc_not_zero(atomic64_t *v)
{
int r;
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 6106b59d3260..6f95023894b7 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -207,8 +207,6 @@ static inline bool arch_atomic64_add_unless(atomic64_t *v, long a, long u)
return true;
}

-#define arch_atomic64_inc_not_zero(v) arch_atomic64_add_unless((v), 1, 0)
-
/*
* arch_atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index b8b14cc2df6c..52b7dcb41769 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -205,11 +205,14 @@ static __always_inline s64 atomic64_dec_return(atomic64_t *v)
return arch_atomic64_dec_return(v);
}

+#ifdef arch_atomic64_inc_not_zero
+#define atomic64_inc_not_zero atomic64_inc_not_zero
static __always_inline s64 atomic64_inc_not_zero(atomic64_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_inc_not_zero(v);
}
+#endif

static __always_inline s64 atomic64_dec_if_positive(atomic64_t *v)
{
diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h
index 8d28eb010d0d..e9a94b7a4d0a 100644
--- a/include/asm-generic/atomic64.h
+++ b/include/asm-generic/atomic64.h
@@ -62,6 +62,5 @@ extern int atomic64_add_unless(atomic64_t *v, long long a, long long u);
#define atomic64_dec(v) atomic64_sub(1LL, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)

#endif /* _ASM_GENERIC_ATOMIC64_H */
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index ec36a1375c9d..e83f12ec7f2d 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -1048,6 +1048,17 @@ static inline int atomic_dec_if_positive(atomic_t *v)
#define atomic64_try_cmpxchg_release atomic64_try_cmpxchg
#endif /* atomic64_try_cmpxchg */

+/**
+ * atomic64_inc_not_zero - increment unless the number is zero
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically increments @v by 1, so long as @v is non-zero.
+ * Returns non-zero if @v was non-zero, and zero otherwise.
+ */
+#ifndef atomic64_inc_not_zero
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+#endif
+
#ifndef atomic64_andnot
static inline void atomic64_andnot(long long i, atomic64_t *v)
{
--
2.11.0