NetBSD/sys/arch/sun3/include/psl.h
thorpej eb20bbc780 Change the semantics of splsoftclock() to be like other spl*() functions,
that is priority is rasied.  Add a new spllowersoftclock() to provide the
atomic drop-to-softclock semantics that the old splsoftclock() provided,
and update calls accordingly.

This fixes a problem with using the "rnd" pseudo-device from within
interrupt context to extract random data (e.g. from within the softnet
interrupt) where doing so would incorrectly unblock interrupts (causing
all sorts of lossage).

XXX 4 platforms do not have priority-raising capability: newsmips, sparc,
XXX sparc64, and VAX.  This platforms still have this bug until their
XXX spl*() functions are fixed.
1999-08-05 18:08:08 +00:00

112 lines
3.9 KiB
C

/* $NetBSD: psl.h,v 1.15 1999/08/05 18:08:14 thorpej Exp $ */
/*-
* Copyright (c) 1996 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Gordon W. Ross.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
#ifndef _SUN3_PSL_H_
#define _SUN3_PSL_H_
#include <m68k/psl.h>
/* Could define this in the common <m68k/psl.h> instead. */
#if defined(_KERNEL) && !defined(_LOCORE)
/*
* Define inline functions for PSL manipulation.
* These are as close to macros as one can get.
* When not optimizing gcc will call the locore.s
* functions by the same names, so breakpoints on
* these functions will work normally, etc.
* (See the GCC extensions info document.)
*/
static __inline int _getsr __P((void));
/* Get current sr value. */
static __inline int
_getsr(void)
{
register int rv;
__asm __volatile ("clrl %0; movew sr,%0" : "&=d" (rv));
return (rv);
}
/*
* The rest of this is sun3 specific, because other ports may
* need to do special things in spl0() (i.e. simulate SIR).
* Suns have a REAL interrupt register, so spl0() and splx(s)
* have no need to check for any simulated interrupts, etc.
*/
#define spl0() _spl0() /* we have real software interrupts */
#define splx(x) _spl(x)
/* IPL used by soft interrupts: netintr(), softclock() */
#define spllowersoftclock() spl1()
#define splsoftclock() splraise1()
#define splsoftnet() splraise1()
/* Highest block device (strategy) IPL. */
#define splbio() splraise2()
/* Highest network interface IPL. */
#define splnet() splraise3()
/* Highest tty device IPL. */
#define spltty() splraise4()
/*
* Requirement: imp >= (highest network, tty, or disk IPL)
* This is used mostly in the VM code. (Why not splvm?)
* Note that the VM code runs at spl7 during kernel
* initialization, and later at spl0, so we have to
* use splraise to avoid enabling interrupts early.
*/
#define splimp() _splraise(PSL_S|PSL_IPL4)
/* Intersil clock hardware interrupts (hard-wired at 5) */
#define splclock() splraise5()
#define splstatclock() splclock()
/* Block out all interrupts (except NMI of course). */
#define splhigh() spl7()
#define splsched() spl7()
#endif /* KERNEL && !_LOCORE */
#endif /* _SUN3_PSL_H_ */