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linux
arm64: atomics: tidy up common atomic{,64}_* macros
The common (i.e. identical for ll/sc and lse) atomic macros in atomic.h
are needlessley different for atomic_t and atomic64_t.
This patch tidies up the definitions to make them consistent across the
two atomic types and factors out common code such as the add_unless
implementation based on cmpxchg.
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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arch/arm64/include/asm/atomic.h
+38
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arch/arm64/include/asm/atomic.h
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#include <asm/barrier.h>
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#include <asm/lse.h>
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#define ATOMIC_INIT(i) { (i) }
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-
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#ifdef __KERNEL__
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#define __ARM64_IN_ATOMIC_IMPL
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#include <asm/cmpxchg.h>
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/*
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* On ARM, ordinary assignment (str instruction) doesn't clear the local
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* strex/ldrex monitor on some implementations. The reason we can use it for
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* atomic_set() is the clrex or dummy strex done on every exception return.
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*/
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#define atomic_read(v) ACCESS_ONCE((v)->counter)
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#define atomic_set(v,i) (((v)->counter) = (i))
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#define ___atomic_add_unless(v, a, u, sfx) \
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({ \
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typeof((v)->counter) c, old; \
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\
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c = atomic##sfx##_read(v); \
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while (c != (u) && \
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(old = atomic##sfx##_cmpxchg((v), c, c + (a))) != c) \
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c = old; \
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c; \
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})
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#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
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#define ATOMIC_INIT(i) { (i) }
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static inline int __atomic_add_unless(atomic_t *v, int a, int u)
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{
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int c, old;
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#define atomic_read(v) READ_ONCE((v)->counter)
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#define atomic_set(v, i) (((v)->counter) = (i))
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#define atomic_xchg(v, new) xchg(&((v)->counter), (new))
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c = atomic_read(v);
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while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c)
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c = old;
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return c;
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}
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#define atomic_inc(v) atomic_add(1, v)
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#define atomic_dec(v) atomic_sub(1, v)
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#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
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#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
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#define atomic_inc_return(v) (atomic_add_return(1, v))
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#define atomic_dec_return(v) (atomic_sub_return(1, v))
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#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
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#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
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#define atomic_andnot atomic_andnot
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#define atomic_inc(v) atomic_add(1, (v))
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#define atomic_dec(v) atomic_sub(1, (v))
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#define atomic_inc_return(v) atomic_add_return(1, (v))
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#define atomic_dec_return(v) atomic_sub_return(1, (v))
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#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
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#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
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#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
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#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
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#define __atomic_add_unless(v, a, u) ___atomic_add_unless(v, a, u,)
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#define atomic_andnot atomic_andnot
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/*
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* 64-bit atomic operations.
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*/
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#define ATOMIC64_INIT(i) { (i) }
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#define ATOMIC64_INIT ATOMIC_INIT
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#define atomic64_read atomic_read
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#define atomic64_set atomic_set
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#define atomic64_xchg atomic_xchg
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#define atomic64_read(v) ACCESS_ONCE((v)->counter)
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#define atomic64_set(v,i) (((v)->counter) = (i))
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#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
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static inline int atomic64_add_unless(atomic64_t *v, long a, long u)
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{
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long c, old;
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c = atomic64_read(v);
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while (c != u && (old = atomic64_cmpxchg((v), c, c + a)) != c)
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c = old;
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return c != u;
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}
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#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
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#define atomic64_inc(v) atomic64_add(1LL, (v))
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#define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
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#define atomic64_inc(v) atomic64_add(1, (v))
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#define atomic64_dec(v) atomic64_sub(1, (v))
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#define atomic64_inc_return(v) atomic64_add_return(1, (v))
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#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
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#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
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#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
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#define atomic64_dec(v) atomic64_sub(1LL, (v))
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#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
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#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
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#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
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#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
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#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
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#define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0)
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#define atomic64_add_unless(v, a, u) (___atomic_add_unless(v, a, u, 64) != u)
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#define atomic64_andnot atomic64_andnot
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#define atomic64_andnot atomic64_andnot
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#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
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#endif
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#endif