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mirror of https://git.FreeBSD.org/src.git synced 2024-12-23 11:18:54 +00:00
freebsd/sys/kern/init_smp.c
Steve Passe 75877d5a93 removed the "#error ..." line preventing casual invokation of SMP_AUTOSTART.
autostart appears to be working now, at least on my dual P6.
I have no explanation why....
1997-05-06 07:10:06 +00:00

318 lines
7.8 KiB
C

/*
* Copyright (c) 1996, Peter Wemm <peter@freebsd.org>
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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: init_smp.c,v 1.5 1997/05/04 02:08:09 peter Exp $
*/
#include "opt_smp.h"
#include "opt_smp_autostart.h"
#include <sys/param.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/sysent.h>
#include <sys/reboot.h>
#include <sys/sysproto.h>
#include <sys/vmmeter.h>
#include <sys/lock.h>
#include <machine/cpu.h>
#include <machine/smp.h>
#include <machine/smptests.h> /** IGNORE_IDLEPROCS */
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <sys/user.h>
int smp_active = 0; /* are the APs allowed to run? */
static int
sysctl_smp_active SYSCTL_HANDLER_ARGS
{
int error = 0;
int new_val;
error = SYSCTL_OUT(req, &smp_active, sizeof(int));
if (error || !req->newptr)
return (error);
error = SYSCTL_IN(req, &new_val, sizeof(int));
if (error)
return (error);
if (new_val < 1)
return (EBUSY);
if (new_val > mp_ncpus)
return (EINVAL);
smp_active = new_val;
return (0);
}
SYSCTL_PROC(_kern, OID_AUTO, smp_active, CTLTYPE_INT|CTLFLAG_RW,
0, 0, &sysctl_smp_active, "I", "");
int smp_cpus = 0; /* how many cpu's running */
SYSCTL_INT(_kern, OID_AUTO, smp_cpus, CTLFLAG_RD, &smp_cpus, 0, "");
int idle_debug = 0;
SYSCTL_INT(_kern, OID_AUTO, idle_debug, CTLFLAG_RW, &idle_debug, 0, "");
int invltlb_ok = 0; /* throttle smp_invltlb() till safe */
#if defined(IGNORE_IDLEPROCS)
int ignore_idleprocs = 1;
#else
int ignore_idleprocs = 0;
#endif
SYSCTL_INT(_kern, OID_AUTO, ignore_idleprocs, CTLFLAG_RW, &ignore_idleprocs,
0, "");
static void smp_kickoff __P((void *dummy));
SYSINIT(smpkick, SI_SUB_SMP, SI_ORDER_FIRST, smp_kickoff, NULL)
static void smp_idleloop __P((void *));
void secondary_main __P((void));
static int idle_loops = 0;
void boot_unlock __P((void));
struct proc *SMPidleproc[NCPU];
static int cpu_starting = -1;
static void
smp_kickoff(dummy)
void *dummy;
{
int rval[2]; /* return from fork */
struct proc *p;
int i;
/*
* Create the appropriate number of cpu-idle-eaters
*/
for (i = 0; i < mp_ncpus; i++) {
/* kernel thread*/
if (fork(&proc0, NULL, rval))
panic("cannot fork idle process");
p = pfind(rval[0]);
cpu_set_fork_handler(p, smp_idleloop, NULL);
SMPidleproc[i] = p;
p->p_flag |= P_INMEM | P_SYSTEM | P_IDLEPROC;
sprintf(p->p_comm, "cpuidle%d", i);
/*
* PRIO_IDLE is the last scheduled of the three
* classes and we choose the lowest priority possible
* for there.
*/
p->p_rtprio.type = RTP_PRIO_IDLE;
p->p_rtprio.prio = RTP_PRIO_MAX;
}
}
#define MSG_CPU_MADEIT \
printf("SMP: TADA! CPU #%d made it into the scheduler!.\n", \
cpunumber())
#define MSG_NEXT_CPU \
printf("SMP: %d of %d CPU's online. Unlocking next CPU..\n", \
smp_cpus, mp_ncpus)
#define MSG_FINAL_CPU \
printf("SMP: All %d CPU's are online!\n", \
smp_cpus)
#define MSG_TOOMANY_CPU \
printf("SMP: Hey! Too many cpu's started, %d of %d running!\n", \
smp_cpus, mp_ncpus)
/*
* This is run by the secondary processor to kick things off.
* It basically drops into the switch routine to pick the first
* available process to run, which is probably an idle process.
*/
void
secondary_main()
{
get_mplock();
/*
* Record our ID so we know when we've released the mp_stk.
* We must remain single threaded through this.
*/
cpu_starting = cpunumber();
smp_cpus++;
printf("SMP: AP CPU #%d LAUNCHED!! Starting Scheduling...\n",
cpunumber());
curproc = NULL; /* ensure no context to save */
cpu_switch(curproc); /* start first process */
panic("switch returned!");
}
/*
* The main program loop for the idle process
*/
static void
smp_idleloop(dummy)
void *dummy;
{
int dcnt = 0;
/*
* This code is executed only on startup of the idleprocs
* The fact that this is executed is an indication that the
* idle procs are online and it's safe to kick off the first
* AP cpu.
*/
if ( ++idle_loops == mp_ncpus ) {
printf("SMP: All idle procs online.\n");
#if defined(SMP_AUTOSTART)
printf("SMP: *** AUTO *** starting 1st AP!\n");
smp_cpus = 1;
smp_active = mp_ncpus; /* XXX */
boot_unlock();
#else
printf("You can now activate SMP processing, use: sysctl -w kern.smp_active=%d\n", mp_ncpus);
#endif /* SMP_AUTOSTART */
}
spl0();
rel_mplock();
while (1) {
/*
* make the optimiser assume nothing about the
* which*qs variables
*/
__asm __volatile("" : : : "memory");
#if !defined(SMP_AUTOSTART)
/*
* Alternate code to enable a lockstep startup
* via sysctl instead of automatically.
*/
if (smp_cpus == 0 && smp_active != 0) {
get_mplock();
printf("SMP: Starting 1st AP!\n");
smp_cpus = 1;
smp_active = mp_ncpus; /* XXX */
boot_unlock();
rel_mplock();
}
#endif /* !SMP_AUTOSTART */
/*
* If smp_active is set to (say) 1, we want cpu id's
* 1,2,etc to freeze here.
*/
if (smp_active && smp_active <= cpunumber()) {
get_mplock();
printf("SMP: cpu#%d freezing\n", cpunumber());
wakeup((caddr_t)&smp_active);
rel_mplock();
while (smp_active <= cpunumber()) {
__asm __volatile("" : : : "memory");
}
get_mplock();
printf("SMP: cpu#%d waking up!\n", cpunumber());
rel_mplock();
}
if (whichqs || whichrtqs || (!ignore_idleprocs && whichidqs)) {
/* grab lock for kernel "entry" */
get_mplock();
/* We need to retest due to the spin lock */
__asm __volatile("" : : : "memory");
if (whichqs || whichrtqs ||
(!ignore_idleprocs && whichidqs)) {
splhigh();
if (curproc)
setrunqueue(curproc);
cnt.v_swtch++;
cpu_switch(curproc);
microtime(&runtime);
if (cpu_starting != -1 &&
cpu_starting == cpunumber()) {
/*
* TADA! we have arrived! unlock the
* next cpu now that we have released
* the single mp_stk.
*/
MSG_CPU_MADEIT;
cpu_starting = -1;
if (smp_cpus < mp_ncpus) {
MSG_NEXT_CPU;
boot_unlock();
} else if (smp_cpus > mp_ncpus) {
MSG_TOOMANY_CPU;
panic("too many cpus");
} else {
MSG_FINAL_CPU;
/*
* It's safe to send IPI's now
* that all CPUs are online.
*/
invltlb_ok = 1;
}
/* Init local apic for irq's */
apic_initialize(0);
}
(void)spl0();
}
rel_mplock();
} else {
dcnt++;
if (idle_debug && (dcnt % idle_debug) == 0) {
get_mplock();
printf("idleproc pid#%d on cpu#%d, lock %08x\n",
curproc->p_pid, cpunumber(), mp_lock);
rel_mplock();
}
}
}
}