freebsd-nq/sys/i386/include/spl.h
Bruce Evans d81fba0cda Add variable `idelayed' and macros setdelayed() and schedsofttty()
to access it.  setdelayed() actually ORs the bits in `idelayed' into
`ipending' and clears `idelayed'.

Call setdelayed() every (normal) clock tick to convert delayed
interrupts into pending ones.

Drivers can set bits in `idelayed' at any time to schedule an interrupt
at the next clock tick.  This is more efficient than calling timeout().
Currently only software interrupts can be scheduled.
1995-05-11 07:44:40 +00:00

144 lines
5.1 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 1.7 1995/05/11 00:13:01 wollman 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.
*/
#define SWI_TTY_MASK (SWI_TTY_PENDING | SWI_CLOCK_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
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() */
/*
* ipending has to be volatile so that it is read every time it is accessed
* in splx() and spl0(), but we don't want it to be read nonatomically when
* it is changed. Pretending that ipending is a plain int happens to give
* suitable atomic code for "ipending |= constant;".
*/
#define setdelayed() (*(unsigned *)&ipending |= loadandclear(&idelayed))
#define setsoftast() (*(unsigned *)&ipending |= SWI_AST_PENDING)
#define setsoftclock() (*(unsigned *)&ipending |= SWI_CLOCK_PENDING)
#define setsoftnet() (*(unsigned *)&ipending |= SWI_NET_PENDING)
#define setsofttty() (*(unsigned *)&ipending |= SWI_TTY_PENDING)
#define schedsofttty() (*(unsigned *)&idelayed |= SWI_TTY_PENDING)
void unpend_V __P((void));
#ifdef __GNUC__
void splz __P((void));
#define GENSPL(name, set_cpl) \
static __inline int name(void) \
{ \
unsigned x; \
\
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)
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_ */