[RFC][PATCH 21/24] atomic: Provide atomic_{or,xor,and}

From: Peter Zijlstra
Date: Thu Jul 09 2015 - 13:56:14 EST


Implement atomic logic ops -- atomic_{or,xor,and}.

These will replace the atomic_{set,clear}_mask functions that are
available on some archs.


Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/x86/include/asm/atomic.h | 2 --
include/asm-generic/atomic.h | 21 ++++++++++++++++-----
include/asm-generic/atomic64.h | 3 +++
include/linux/atomic.h | 13 -------------
lib/atomic64.c | 3 +++
5 files changed, 22 insertions(+), 20 deletions(-)

--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -195,8 +195,6 @@ ATOMIC_OP(and)
ATOMIC_OP(or)
ATOMIC_OP(xor)

-#define CONFIG_ARCH_HAS_ATOMIC_OR
-
#undef ATOMIC_OP

/**
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -98,20 +98,31 @@ ATOMIC_OP_RETURN(add, +)
ATOMIC_OP_RETURN(sub, -)
#endif

-#ifndef atomic_clear_mask
+#ifndef atomic_and
ATOMIC_OP(and, &)
-#define atomic_clear_mask(i, v) atomic_and(~(i), (v))
#endif

-#ifndef atomic_set_mask
-#define CONFIG_ARCH_HAS_ATOMIC_OR
+#ifndef atomic_or
ATOMIC_OP(or, |)
-#define atomic_set_mask(i, v) atomic_or((i), (v))
+#endif
+
+#ifndef atomic_xor
+ATOMIC_OP(xor, ^)
#endif

#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

+static inline __deprecated void atomic_clear_mask(unsigned int mask, atomic_t *v)
+{
+ atomic_and(~mask, v);
+}
+
+static inline __deprecated void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+ atomic_or(mask, v);
+}
+
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
--- a/include/asm-generic/atomic64.h
+++ b/include/asm-generic/atomic64.h
@@ -31,6 +31,9 @@ extern long long atomic64_##op##_return(

ATOMIC64_OPS(add)
ATOMIC64_OPS(sub)
+ATOMIC64_OP(and)
+ATOMIC64_OP(or)
+ATOMIC64_OP(xor)

#undef ATOMIC64_OPS
#undef ATOMIC64_OP_RETURN
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -111,19 +111,6 @@ static inline int atomic_dec_if_positive
}
#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 */
-
#include <asm-generic/atomic-long.h>
#ifdef CONFIG_GENERIC_ATOMIC64
#include <asm-generic/atomic64.h>
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -102,6 +102,9 @@ EXPORT_SYMBOL(atomic64_##op##_return);

ATOMIC64_OPS(add, +=)
ATOMIC64_OPS(sub, -=)
+ATOMIC64_OP(and, &=)
+ATOMIC64_OP(or, |=)
+ATOMIC64_OP(xor, ^=)

#undef ATOMIC64_OPS
#undef ATOMIC64_OP_RETURN


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