atomics/treewide: Make test ops optional
Some of the atomics return the result of a test applied after the atomic
operation, and almost all architectures implement these as trivial
wrappers around the underlying atomic. Specifically:
* <atomic>_inc_and_test(v) is (<atomic>_inc_return(v) == 0)
* <atomic>_dec_and_test(v) is (<atomic>_dec_return(v) == 0)
* <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0)
* <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v) < 0)
Rather than have these definitions duplicated in all architectures, with
minor inconsistencies in formatting and documentation, let's make these
operations optional, with default fallbacks as above. Implementations
must now provide a preprocessor symbol.
The instrumented atomics are updated accordingly.
Both x86 and m68k have custom implementations, which are left as-is,
given preprocessor symbols to avoid being overridden.
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: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-16-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index 2b487f2..6b64c20 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -225,29 +225,41 @@ static __always_inline s64 atomic64_dec_if_positive(atomic64_t *v)
return arch_atomic64_dec_if_positive(v);
}
+#ifdef arch_atomic_dec_and_test
+#define atomic_dec_and_test atomic_dec_and_test
static __always_inline bool atomic_dec_and_test(atomic_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic_dec_and_test(v);
}
+#endif
+#ifdef arch_atomic64_dec_and_test
+#define atomic64_dec_and_test atomic64_dec_and_test
static __always_inline bool atomic64_dec_and_test(atomic64_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_dec_and_test(v);
}
+#endif
+#ifdef arch_atomic_inc_and_test
+#define atomic_inc_and_test atomic_inc_and_test
static __always_inline bool atomic_inc_and_test(atomic_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic_inc_and_test(v);
}
+#endif
+#ifdef arch_atomic64_inc_and_test
+#define atomic64_inc_and_test atomic64_inc_and_test
static __always_inline bool atomic64_inc_and_test(atomic64_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_inc_and_test(v);
}
+#endif
static __always_inline int atomic_add_return(int i, atomic_t *v)
{
@@ -333,29 +345,41 @@ static __always_inline s64 atomic64_fetch_xor(s64 i, atomic64_t *v)
return arch_atomic64_fetch_xor(i, v);
}
+#ifdef arch_atomic_sub_and_test
+#define atomic_sub_and_test atomic_sub_and_test
static __always_inline bool atomic_sub_and_test(int i, atomic_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic_sub_and_test(i, v);
}
+#endif
+#ifdef arch_atomic64_sub_and_test
+#define atomic64_sub_and_test atomic64_sub_and_test
static __always_inline bool atomic64_sub_and_test(s64 i, atomic64_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_sub_and_test(i, v);
}
+#endif
+#ifdef arch_atomic_add_negative
+#define atomic_add_negative atomic_add_negative
static __always_inline bool atomic_add_negative(int i, atomic_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic_add_negative(i, v);
}
+#endif
+#ifdef arch_atomic64_add_negative
+#define atomic64_add_negative atomic64_add_negative
static __always_inline bool atomic64_add_negative(s64 i, atomic64_t *v)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_add_negative(i, v);
}
+#endif
static __always_inline unsigned long
cmpxchg_size(volatile void *ptr, unsigned long old, unsigned long new, int size)
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index 757e458..40cab85 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -186,11 +186,6 @@ ATOMIC_OP(xor, ^)
#include <linux/irqflags.h>
-static inline int atomic_add_negative(int i, atomic_t *v)
-{
- return atomic_add_return(i, v) < 0;
-}
-
static inline void atomic_add(int i, atomic_t *v)
{
atomic_add_return(i, v);
@@ -214,10 +209,6 @@ static inline void atomic_dec(atomic_t *v)
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
-#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
-#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
-#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
-
#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h
index 4946010..d3827ab 100644
--- a/include/asm-generic/atomic64.h
+++ b/include/asm-generic/atomic64.h
@@ -56,13 +56,9 @@ extern long long atomic64_xchg(atomic64_t *v, long long new);
extern long long atomic64_fetch_add_unless(atomic64_t *v, long long a, long long u);
#define atomic64_fetch_add_unless atomic64_fetch_add_unless
-#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
#define atomic64_inc(v) atomic64_add(1LL, (v))
#define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
-#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
-#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
#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)
#endif /* _ASM_GENERIC_ATOMIC64_H */
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 530562a..3ee8da9 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -569,6 +569,68 @@ static inline bool atomic_add_unless(atomic_t *v, int a, int u)
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#endif
+/**
+ * atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic_inc_and_test
+static inline bool atomic_inc_and_test(atomic_t *v)
+{
+ return atomic_inc_return(v) == 0;
+}
+#endif
+
+/**
+ * atomic_dec_and_test - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#ifndef atomic_dec_and_test
+static inline bool atomic_dec_and_test(atomic_t *v)
+{
+ return atomic_dec_return(v) == 0;
+}
+#endif
+
+/**
+ * atomic_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic_sub_and_test
+static inline bool atomic_sub_and_test(int i, atomic_t *v)
+{
+ return atomic_sub_return(i, v) == 0;
+}
+#endif
+
+/**
+ * atomic_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#ifndef atomic_add_negative
+static inline bool atomic_add_negative(int i, atomic_t *v)
+{
+ return atomic_add_return(i, v) < 0;
+}
+#endif
+
#ifndef atomic_andnot
static inline void atomic_andnot(int i, atomic_t *v)
{
@@ -1091,6 +1153,68 @@ static inline bool atomic64_add_unless(atomic64_t *v, long long a, long long u)
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
#endif
+/**
+ * atomic64_inc_and_test - increment and test
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic64_inc_and_test
+static inline bool atomic64_inc_and_test(atomic64_t *v)
+{
+ return atomic64_inc_return(v) == 0;
+}
+#endif
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#ifndef atomic64_dec_and_test
+static inline bool atomic64_dec_and_test(atomic64_t *v)
+{
+ return atomic64_dec_return(v) == 0;
+}
+#endif
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#ifndef atomic64_sub_and_test
+static inline bool atomic64_sub_and_test(long long i, atomic64_t *v)
+{
+ return atomic64_sub_return(i, v) == 0;
+}
+#endif
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#ifndef atomic64_add_negative
+static inline bool atomic64_add_negative(long long i, atomic64_t *v)
+{
+ return atomic64_add_return(i, v) < 0;
+}
+#endif
+
#ifndef atomic64_andnot
static inline void atomic64_andnot(long long i, atomic64_t *v)
{