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freebsd/sys/i386/include/cpu.h
John Baldwin 688ebe120c - Close races with signals and other AST's being triggered while we are in
the process of exiting the kernel.  The ast() function now loops as long
  as the PS_ASTPENDING or PS_NEEDRESCHED flags are set.  It returns with
  preemption disabled so that any further AST's that arrive via an
  interrupt will be delayed until the low-level MD code returns to user
  mode.
- Use u_int's to store the tick counts for profiling purposes so that we
  do not need sched_lock just to read p_sticks.  This also closes a
  problem where the call to addupc_task() could screw up the arithmetic
  due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
  clear_resched(), and resched_wanted() in favor of direct bit operations
  on p_sflag.
- Fix up locking with sched_lock some.  In addupc_intr(), use sched_lock
  to ensure pr_addr and pr_ticks are updated atomically with setting
  PS_OWEUPC.  In ast() we clear pr_ticks atomically with clearing
  PS_OWEUPC.  We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.

Reviewed by:	bde (mostly)
2001-08-10 22:53:32 +00:00

117 lines
3.8 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_getstack(p) ((p)->p_frame->tf_esp)
#define cpu_setstack(p, ap) ((p)->p_frame->tf_esp = (ap))
#define TRAPF_USERMODE(framep) \
((ISPL((framep)->tf_cs) == SEL_UPL) || ((framep)->tf_eflags & PSL_VM))
#define TRAPF_PC(framep) ((framep)->tf_eip)
#define CLKF_USERMODE(framep) \
((ISPL((framep)->cf_cs) == SEL_UPL) || ((framep)->cf_eflags & PSL_VM))
#define CLKF_PC(framep) ((framep)->cf_eip)
/*
* 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[];
extern u_int tsc_present;
void fork_trampoline __P((void));
/*
* Return contents of in-cpu fast counter as a sort of "bogo-time"
* for non-critical timing.
*/
static __inline u_int64_t
get_cyclecount(void)
{
#if defined(I386_CPU) || defined(I486_CPU)
struct timespec tv;
if (!tsc_present) {
nanotime(&tv);
return (tv.tv_sec * (u_int64_t)1000000000 + tv.tv_nsec);
}
#endif
return (rdtsc());
}
#endif
#endif /* !_MACHINE_CPU_H_ */