forked from mirrors/linux
346e91ee09
The mmiowb() macro is horribly difficult to use and drivers will continue to work most of the time if they omit a call when it is required. Rather than rely on driver authors getting this right, push mmiowb() into arch_spin_unlock() for mips. If this is deemed to be a performance issue, a subsequent optimisation could make use of ARCH_HAS_MMIOWB to elide the barrier in cases where no I/O writes were performed inside the critical section. Acked-by: Paul Burton <paul.burton@mips.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
31 lines
822 B
C
31 lines
822 B
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1999, 2000, 06 Ralf Baechle (ralf@linux-mips.org)
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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*/
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#ifndef _ASM_SPINLOCK_H
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#define _ASM_SPINLOCK_H
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#include <asm/processor.h>
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#include <asm/qrwlock.h>
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#include <asm-generic/qspinlock_types.h>
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#define queued_spin_unlock queued_spin_unlock
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/**
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* queued_spin_unlock - release a queued spinlock
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* @lock : Pointer to queued spinlock structure
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*/
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static inline void queued_spin_unlock(struct qspinlock *lock)
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{
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/* This could be optimised with ARCH_HAS_MMIOWB */
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mmiowb();
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smp_store_release(&lock->locked, 0);
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}
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#include <asm/qspinlock.h>
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#endif /* _ASM_SPINLOCK_H */
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