linux/arch/mips/include/asm/spinlock.h
Waiman Long d8d0da4eee locking/arch: Move qrwlock.h include after qspinlock.h
include/asm-generic/qrwlock.h was trying to get arch_spin_is_locked via
asm-generic/qspinlock.h.  However, this does not work because architectures
might be using queued rwlocks but not queued spinlocks (csky), or because they
might be defining their own queued_* macros before including asm/qspinlock.h.

To fix this, ensure that asm/spinlock.h always includes qrwlock.h after
defining arch_spin_is_locked (either directly for csky, or via
asm/qspinlock.h for other architectures).  The only inclusion elsewhere
is in kernel/locking/qrwlock.c.  That one is really unnecessary because
the file is only compiled in SMP configurations (config QUEUED_RWLOCKS
depends on SMP) and in that case linux/spinlock.h already includes
asm/qrwlock.h if needed, via asm/spinlock.h.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Waiman Long <longman@redhat.com>
Fixes: 26128cb6c7e6 ("locking/rwlocks: Add contention detection for rwlocks")
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Ben Gardon <bgardon@google.com>
[Add arch/sparc and kernel/locking parts per discussion with Waiman. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-11 07:59:54 -05:00

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C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999, 2000, 06 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_SPINLOCK_H
#define _ASM_SPINLOCK_H
#include <asm/processor.h>
#include <asm-generic/qspinlock_types.h>
#define queued_spin_unlock queued_spin_unlock
/**
* queued_spin_unlock - release a queued spinlock
* @lock : Pointer to queued spinlock structure
*/
static inline void queued_spin_unlock(struct qspinlock *lock)
{
/* This could be optimised with ARCH_HAS_MMIOWB */
mmiowb();
smp_store_release(&lock->locked, 0);
}
#include <asm/qspinlock.h>
#include <asm/qrwlock.h>
#endif /* _ASM_SPINLOCK_H */