freebsd-dev/sys/i386/include/cpu.h
Jason Evans 0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00

151 lines
5.4 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* 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.
*
* from: @(#)cpu.h 5.4 (Berkeley) 5/9/91
* $FreeBSD$
*/
#ifndef _MACHINE_CPU_H_
#define _MACHINE_CPU_H_
/*
* Definitions unique to i386 cpu support.
*/
#include <machine/psl.h>
#include <machine/frame.h>
#include <machine/segments.h>
#include <machine/globals.h>
/*
* definitions of cpu-dependent requirements
* referenced in generic code
*/
#undef COPY_SIGCODE /* don't copy sigcode above user stack in exec */
#define cpu_exec(p) /* nothing */
#define cpu_swapin(p) /* nothing */
#define cpu_setstack(p, ap) ((p)->p_md.md_regs[SP] = (ap))
#define CLKF_USERMODE(framep) \
((ISPL((framep)->cf_cs) == SEL_UPL) || (framep->cf_eflags & PSL_VM))
#define CLKF_INTR(framep) (intr_nesting_level >= 2)
#if 0
/*
* XXX splsoftclock() is very broken and barely worth fixing. It doesn't
* turn off the clock bit in imen or in the icu. (This is not a serious
* problem at 100 Hz but it is serious at 16000 Hz for pcaudio. softclock()
* can take more than 62.5 usec so clock interrupts are lost.) It doesn't
* check for pending interrupts being unmasked. clkintr() and Xintr0()
* assume that the ipl is high when hardclock() returns. Our SWI_CLOCK
* handling is efficient enough that little is gained by calling
* softclock() directly.
*/
#define CLKF_BASEPRI(framep) ((framep)->cf_ppl == 0)
#else
#define CLKF_BASEPRI(framep) (0)
#endif
#define CLKF_PC(framep) ((framep)->cf_eip)
/*
* Preempt the current process if in interrupt from user mode,
* or after the current trap/syscall if in system mode.
*
* XXX: if astpending is later changed to an |= here due to more flags being
* added, we will have an atomicy problem. The type of atomicy we need is
* a non-locked orl.
*/
#define need_resched() do { \
PCPU_SET(astpending, AST_RESCHED|AST_PENDING); \
} while (0)
#define resched_wanted() (astpending & AST_RESCHED)
/*
* Arrange to handle pending profiling ticks before returning to user mode.
*
* XXX this is now poorly named and implemented. It used to handle only a
* single tick and the P_OWEUPC flag served as a counter. Now there is a
* counter in the proc table and flag isn't really necessary.
*/
#define need_proftick(p) \
do { (p)->p_flag |= P_OWEUPC; aston(); } while (0)
/*
* Notify the current process (p) that it has a signal pending,
* process as soon as possible.
*
* XXX: aston() really needs to be an atomic (not locked, but an orl),
* in case need_resched() is set by an interrupt. But with astpending a
* per-cpu variable this is not trivial to do efficiently. For now we blow
* it off (asynchronous need_resched() conflicts are not critical).
*/
#define signotify(p) aston()
#define aston() do { \
PCPU_SET(astpending, astpending | AST_PENDING); \
} while (0)
#define astoff()
/*
* CTL_MACHDEP definitions.
*/
#define CPU_CONSDEV 1 /* dev_t: console terminal device */
#define CPU_ADJKERNTZ 2 /* int: timezone offset (seconds) */
#define CPU_DISRTCSET 3 /* int: disable resettodr() call */
#define CPU_BOOTINFO 4 /* struct: bootinfo */
#define CPU_WALLCLOCK 5 /* int: indicates wall CMOS clock */
#define CPU_MAXID 6 /* number of valid machdep ids */
#define CTL_MACHDEP_NAMES { \
{ 0, 0 }, \
{ "console_device", CTLTYPE_STRUCT }, \
{ "adjkerntz", CTLTYPE_INT }, \
{ "disable_rtc_set", CTLTYPE_INT }, \
{ "bootinfo", CTLTYPE_STRUCT }, \
{ "wall_cmos_clock", CTLTYPE_INT }, \
}
#ifdef _KERNEL
extern char btext[];
extern char etext[];
#ifndef intr_nesting_level
extern u_char intr_nesting_level;
#endif
void fork_trampoline __P((void));
void fork_return __P((struct proc *, struct trapframe));
#endif
#endif /* !_MACHINE_CPU_H_ */