freebsd-src/sys/i386/include/spl.h
Bruce Evans 7baccf64d3 Fixed lots of warnings about unportable casts of pointers to volatile
variables: don't depend on the compiler generating atomic code to set
the variables - use inline asm to specify the atomic instruction(s)
explicitly.
1996-07-01 20:16:10 +00:00

154 lines
5.6 KiB
C

/*-
* Copyright (c) 1993 The Regents of the University of California.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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 REGENTS 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 REGENTS 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.
*
* $Id: spl.h,v 1.14 1996/05/18 03:36:42 dyson Exp $
*/
#ifndef _MACHINE_IPL_H_
#define _MACHINE_IPL_H_
#include <machine/ipl.h> /* XXX "machine" means cpu for i386 */
/*
* Software interrupt bit numbers in priority order. The priority only
* determines which swi will be dispatched next; a higher priority swi
* may be dispatched when a nested h/w interrupt handler returns.
*/
#define SWI_TTY (NHWI + 0)
#define SWI_NET (NHWI + 1)
#define SWI_CLOCK 30
#define SWI_AST 31
/*
* Corresponding interrupt-pending bits for ipending.
*/
#define SWI_TTY_PENDING (1 << SWI_TTY)
#define SWI_NET_PENDING (1 << SWI_NET)
#define SWI_CLOCK_PENDING (1 << SWI_CLOCK)
#define SWI_AST_PENDING (1 << SWI_AST)
/*
* Corresponding interrupt-disable masks for cpl. The ordering is now by
* inclusion (where each mask is considered as a set of bits). Everything
* except SWI_AST_MASK includes SWI_CLOCK_MASK so that softclock() doesn't
* run while other swi handlers are running and timeout routines can call
* swi handlers. Everything includes SWI_AST_MASK so that AST's are masked
* until just before return to user mode. SWI_TTY_MASK includes SWI_NET_MASK
* in case tty interrupts are processed at splsofttty() for a tty that is in
* SLIP or PPP line discipline (this is weaker than merging net_imask with
* tty_imask in isa.c - splimp() must mask hard and soft tty interrupts, but
* spltty() apparently only needs to mask soft net interrupts).
*/
#define SWI_TTY_MASK (SWI_TTY_PENDING | SWI_CLOCK_MASK | SWI_NET_MASK)
#define SWI_NET_MASK (SWI_NET_PENDING | SWI_CLOCK_MASK)
#define SWI_CLOCK_MASK (SWI_CLOCK_PENDING | SWI_AST_MASK)
#define SWI_AST_MASK SWI_AST_PENDING
#define SWI_MASK (~HWI_MASK)
#ifndef LOCORE
/*
* cpl is preserved by interrupt handlers so it is effectively nonvolatile.
* ipending and idelayed are changed by interrupt handlers so they are
* volatile.
*/
extern unsigned bio_imask; /* group of interrupts masked with splbio() */
extern unsigned cpl; /* current priority level mask */
extern volatile unsigned idelayed; /* interrupts to become pending */
extern volatile unsigned ipending; /* active interrupts masked by cpl */
extern unsigned net_imask; /* group of interrupts masked with splimp() */
extern unsigned stat_imask; /* interrupts masked with splstatclock() */
extern unsigned tty_imask; /* group of interrupts masked with spltty() */
/*
* The volatile bitmap variables must be set atomically. This normally
* involves using a machine-dependent bit-set or `or' instruction.
*/
#define setdelayed() setbits(&ipending, loadandclear(&idelayed))
#define setsoftast() setbits(&ipending, SWI_AST_PENDING)
#define setsoftclock() setbits(&ipending, SWI_CLOCK_PENDING)
#define setsoftnet() setbits(&ipending, SWI_NET_PENDING)
#define setsofttty() setbits(&ipending, SWI_TTY_PENDING)
#define schedsofttty() setbits(&idelayed, SWI_TTY_PENDING)
#define schedsoftnet() setbits(&idelayed, SWI_NET_PENDING)
#define softclockpending() (ipending & SWI_CLOCK_PENDING)
#ifdef __GNUC__
void splz __P((void));
#define GENSPL(name, set_cpl) \
static __inline int name(void) \
{ \
unsigned x; \
\
__asm __volatile("" : : : "memory"); \
x = cpl; \
set_cpl; \
return (x); \
}
GENSPL(splbio, cpl |= bio_imask)
GENSPL(splclock, cpl = HWI_MASK | SWI_MASK)
GENSPL(splhigh, cpl = HWI_MASK | SWI_MASK)
GENSPL(splimp, cpl |= net_imask)
GENSPL(splnet, cpl |= SWI_NET_MASK)
GENSPL(splsoftclock, cpl = SWI_CLOCK_MASK)
GENSPL(splsofttty, cpl |= SWI_TTY_MASK)
GENSPL(splstatclock, cpl |= stat_imask)
GENSPL(spltty, cpl |= tty_imask)
GENSPL(splvm, cpl |= net_imask | bio_imask)
static __inline void
spl0(void)
{
cpl = SWI_AST_MASK;
if (ipending & ~SWI_AST_MASK)
splz();
}
static __inline void
splx(int ipl)
{
cpl = ipl;
if (ipending & ~ipl)
splz();
}
#endif /* __GNUC__ */
#endif /* !LOCORE */
#endif /* !_MACHINE_IPL_H_ */