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freebsd/sys/i386/include/critical.h
John Baldwin eb2a2211ff Revert the critical section implementation to disable interrupts via
cli/sti now that we support many more than 32 interrupt sources.
2003-11-03 21:06:54 +00:00

95 lines
3.0 KiB
C

/*-
* Copyright (c) 2002 Matthew Dillon. All Rights Reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This file contains prototypes and high-level inlines related to
* machine-level critical function support:
*
* cpu_critical_enter() - inlined
* cpu_critical_exit() - inlined
* cpu_critical_fork_exit() - prototyped
* related support functions residing
* in <arch>/<arch>/critical.c - prototyped
*
* $FreeBSD$
*/
#ifndef _MACHINE_CRITICAL_H_
#define _MACHINE_CRITICAL_H_
__BEGIN_DECLS
/*
* Prototypes - see <arch>/<arch>/critical.c
*/
void cpu_critical_fork_exit(void);
#ifdef __GNUC__
/*
* cpu_critical_enter:
*
* This routine is called from critical_enter() on the 0->1 transition
* of td_critnest, prior to it being incremented to 1.
*
* If new-style critical section handling we do not have to do anything.
* However, as a side effect any interrupts occuring while td_critnest
* is non-zero will be deferred.
*/
static __inline void
cpu_critical_enter(void)
{
curthread->td_md.md_savecrit = intr_disable();
}
/*
* cpu_critical_exit:
*
* This routine is called from critical_exit() on a 1->0 transition
* of td_critnest, after it has been decremented to 0. We are
* exiting the last critical section.
*
* Note that the td->critnest (1->0) transition interrupt race against
* our int_pending/unpend() check below is handled by the interrupt
* code for us, so we do not have to do anything fancy.
*/
static __inline void
cpu_critical_exit(void)
{
intr_restore(curthread->td_md.md_savecrit);
}
#else /* !__GNUC__ */
void cpu_critical_enter(void)
void cpu_critical_exit(void)
#endif /* __GNUC__ */
__END_DECLS
#endif /* !_MACHINE_CRITICAL_H_ */