b3a2a05f91
The conditional inc/dec ops differ for atomic_t and atomic64_t: - atomic_inc_unless_positive() is optional for atomic_t, and doesn't exist for atomic64_t. - atomic_dec_unless_negative() is optional for atomic_t, and doesn't exist for atomic64_t. - atomic_dec_if_positive is optional for atomic_t, and is mandatory for atomic64_t. Let's make these consistently optional for both. At the same time, let's clean up the existing fallbacks to use atomic_try_cmpxchg(). The instrumented atomics are updated accordingly. 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: Peter Zijlstra (Intel) <peterz@infradead.org> 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/20180621121321.4761-18-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
61 lines
1.9 KiB
C
61 lines
1.9 KiB
C
/*
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* Generic implementation of 64-bit atomics using spinlocks,
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* useful on processors that don't have 64-bit atomic instructions.
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*
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* Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_GENERIC_ATOMIC64_H
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#define _ASM_GENERIC_ATOMIC64_H
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#include <linux/types.h>
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typedef struct {
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long long counter;
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} atomic64_t;
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#define ATOMIC64_INIT(i) { (i) }
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extern long long atomic64_read(const atomic64_t *v);
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extern void atomic64_set(atomic64_t *v, long long i);
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#define atomic64_set_release(v, i) atomic64_set((v), (i))
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#define ATOMIC64_OP(op) \
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extern void atomic64_##op(long long a, atomic64_t *v);
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#define ATOMIC64_OP_RETURN(op) \
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extern long long atomic64_##op##_return(long long a, atomic64_t *v);
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#define ATOMIC64_FETCH_OP(op) \
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extern long long atomic64_fetch_##op(long long a, atomic64_t *v);
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#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)
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ATOMIC64_OPS(add)
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ATOMIC64_OPS(sub)
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#undef ATOMIC64_OPS
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#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op)
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ATOMIC64_OPS(and)
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ATOMIC64_OPS(or)
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ATOMIC64_OPS(xor)
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#undef ATOMIC64_OPS
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#undef ATOMIC64_FETCH_OP
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#undef ATOMIC64_OP_RETURN
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#undef ATOMIC64_OP
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extern long long atomic64_dec_if_positive(atomic64_t *v);
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#define atomic64_dec_if_positive atomic64_dec_if_positive
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extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
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extern long long atomic64_xchg(atomic64_t *v, long long new);
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extern long long atomic64_fetch_add_unless(atomic64_t *v, long long a, long long u);
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#define atomic64_fetch_add_unless atomic64_fetch_add_unless
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#endif /* _ASM_GENERIC_ATOMIC64_H */
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