[RFC][PATCH 20/24] x86: Provide atomic_{or,xor,and}

From: Peter Zijlstra
Date: Thu Jul 09 2015 - 13:56:21 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 | 35 ++++++++++++++++++++++++++---------
arch/x86/include/asm/atomic64_32.h | 14 ++++++++++++++
arch/x86/include/asm/atomic64_64.h | 15 +++++++++++++++
3 files changed, 55 insertions(+), 9 deletions(-)

--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -182,6 +182,23 @@ static inline int atomic_xchg(atomic_t *
return xchg(&v->counter, new);
}

+#define ATOMIC_OP(op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ asm volatile(LOCK_PREFIX #op"l %1,%0" \
+ : "+m" (v->counter) \
+ : "ir" (i) \
+ : "memory"); \
+}
+
+ATOMIC_OP(and)
+ATOMIC_OP(or)
+ATOMIC_OP(xor)
+
+#define CONFIG_ARCH_HAS_ATOMIC_OR
+
+#undef ATOMIC_OP
+
/**
* __atomic_add_unless - add unless the number is already a given value
* @v: pointer of type atomic_t
@@ -219,15 +236,15 @@ static __always_inline short int atomic_
return *v;
}

-/* These are x86-specific, used by some header files */
-#define atomic_clear_mask(mask, addr) \
- asm volatile(LOCK_PREFIX "andl %0,%1" \
- : : "r" (~(mask)), "m" (*(addr)) : "memory")
-
-#define atomic_set_mask(mask, addr) \
- asm volatile(LOCK_PREFIX "orl %0,%1" \
- : : "r" ((unsigned)(mask)), "m" (*(addr)) \
- : "memory")
+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);
+}

#ifdef CONFIG_X86_32
# include <asm/atomic64_32.h>
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -313,4 +313,18 @@ static inline long long atomic64_dec_if_
#undef alternative_atomic64
#undef __alternative_atomic64

+#define ATOMIC64_OP(op, c_op) \
+static inline void atomic64_##op(long long i, atomic64_t *v) \
+{ \
+ long long old, c = 0; \
+ while ((old = atomic64_cmpxchg(v, c, c c_op i)) != c) \
+ c = old; \
+}
+
+ATOMIC64_OP(and, &)
+ATOMIC64_OP(or, |)
+ATOMIC64_OP(xor, ^)
+
+#undef ATOMIC64_OP
+
#endif /* _ASM_X86_ATOMIC64_32_H */
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -220,4 +220,19 @@ static inline long atomic64_dec_if_posit
return dec;
}

+#define ATOMIC64_OP(op) \
+static inline void atomic64_##op(long i, atomic64_t *v) \
+{ \
+ asm volatile(LOCK_PREFIX #op"q %1,%0" \
+ : "+m" (v->counter) \
+ : "ir" (i) \
+ : "memory"); \
+}
+
+ATOMIC64_OP(and)
+ATOMIC64_OP(or)
+ATOMIC64_OP(xor)
+
+#undef ATOMIC64_OP
+
#endif /* _ASM_X86_ATOMIC64_64_H */


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