560cb12a40
Rewrite generic atomic support to only require cmpxchg(), generate all other primitives from that. Furthermore reduce the endless repetition for all these primitives to a few CPP macros. This way we get more for less lines. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140508135852.940119622@infradead.org Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Howells <dhowells@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
55 lines
1.9 KiB
C
55 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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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_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_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(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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#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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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 int atomic64_add_unless(atomic64_t *v, long long a, long long u);
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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_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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#endif /* _ASM_GENERIC_ATOMIC64_H */
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