eccc2da8c0
Several architectures these have a near-identical implementation based on atomic_read() and atomic_cmpxchg() which we can instead define in <linux/atomic.h>, so let's do so, using something close to the existing x86 implementation with try_cmpxchg(). Where an architecture provides its own atomic_fetch_add_unless(), it must define a preprocessor symbol for it. The instrumented atomics are updated accordingly. Note that arch/arc's existing atomic_fetch_add_unless() had redundant barriers, as these are already present in its atomic_cmpxchg() implementation. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@synopsys.com> Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
51 lines
1.3 KiB
C
51 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_SH_ATOMIC_H
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#define __ASM_SH_ATOMIC_H
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#if defined(CONFIG_CPU_J2)
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#include <asm-generic/atomic.h>
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#else
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/*
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* Atomic operations that C can't guarantee us. Useful for
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* resource counting etc..
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*
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*/
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <asm/cmpxchg.h>
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#include <asm/barrier.h>
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#define ATOMIC_INIT(i) { (i) }
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#define atomic_read(v) READ_ONCE((v)->counter)
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#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
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#if defined(CONFIG_GUSA_RB)
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#include <asm/atomic-grb.h>
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#elif defined(CONFIG_CPU_SH4A)
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#include <asm/atomic-llsc.h>
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#else
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#include <asm/atomic-irq.h>
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#endif
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#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
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#define atomic_dec_return(v) atomic_sub_return(1, (v))
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#define atomic_inc_return(v) atomic_add_return(1, (v))
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#define atomic_inc_and_test(v) (atomic_inc_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_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
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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_xchg(v, new) (xchg(&((v)->counter), new))
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#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
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#endif /* CONFIG_CPU_J2 */
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#endif /* __ASM_SH_ATOMIC_H */
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