NetBSD/sys/kern/kern_cpu.c

509 lines
12 KiB
C

/* $NetBSD: kern_cpu.c,v 1.50 2011/08/07 21:38:32 rmind Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009, 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*-
* Copyright (c)2007 YAMAMOTO Takashi,
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_cpu.c,v 1.50 2011/08/07 21:38:32 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/idle.h>
#include <sys/sched.h>
#include <sys/intr.h>
#include <sys/conf.h>
#include <sys/cpu.h>
#include <sys/cpuio.h>
#include <sys/proc.h>
#include <sys/percpu.h>
#include <sys/kernel.h>
#include <sys/kauth.h>
#include <sys/xcall.h>
#include <sys/pool.h>
#include <sys/kmem.h>
#include <sys/select.h>
#include <sys/namei.h>
#include <sys/callout.h>
#include <uvm/uvm_extern.h>
/*
* If the port has state that cpu_data is the first thing in cpu_info,
* verify the claim is true. This will prevent the from getting out
* of sync.
*/
#ifdef __HAVE_CPU_DATA_FIRST
CTASSERT(offsetof(struct cpu_info, ci_data) == 0);
#else
CTASSERT(offsetof(struct cpu_info, ci_data) != 0);
#endif
void cpuctlattach(int);
static void cpu_xc_online(struct cpu_info *);
static void cpu_xc_offline(struct cpu_info *);
dev_type_ioctl(cpuctl_ioctl);
const struct cdevsw cpuctl_cdevsw = {
nullopen, nullclose, nullread, nullwrite, cpuctl_ioctl,
nullstop, notty, nopoll, nommap, nokqfilter,
D_OTHER | D_MPSAFE
};
kmutex_t cpu_lock __cacheline_aligned;
int ncpu __read_mostly;
int ncpuonline __read_mostly;
bool mp_online __read_mostly;
kcpuset_t * kcpuset_attached __read_mostly;
struct cpuqueue cpu_queue __cacheline_aligned
= CIRCLEQ_HEAD_INITIALIZER(cpu_queue);
static struct cpu_info **cpu_infos __read_mostly;
int
mi_cpu_attach(struct cpu_info *ci)
{
int error;
KASSERT(maxcpus > 0);
ci->ci_index = ncpu;
CIRCLEQ_INSERT_TAIL(&cpu_queue, ci, ci_data.cpu_qchain);
TAILQ_INIT(&ci->ci_data.cpu_ld_locks);
__cpu_simple_lock_init(&ci->ci_data.cpu_ld_lock);
/* This is useful for eg, per-cpu evcnt */
snprintf(ci->ci_data.cpu_name, sizeof(ci->ci_data.cpu_name), "cpu%d",
cpu_index(ci));
if (__predict_false(cpu_infos == NULL)) {
cpu_infos =
kmem_zalloc(sizeof(cpu_infos[0]) * maxcpus, KM_SLEEP);
kcpuset_create(&kcpuset_attached, true);
}
cpu_infos[cpu_index(ci)] = ci;
kcpuset_set(kcpuset_attached, ci->ci_index);
sched_cpuattach(ci);
error = create_idle_lwp(ci);
if (error != 0) {
/* XXX revert sched_cpuattach */
return error;
}
if (ci == curcpu())
ci->ci_data.cpu_onproc = curlwp;
else
ci->ci_data.cpu_onproc = ci->ci_data.cpu_idlelwp;
percpu_init_cpu(ci);
softint_init(ci);
callout_init_cpu(ci);
xc_init_cpu(ci);
pool_cache_cpu_init(ci);
selsysinit(ci);
cache_cpu_init(ci);
TAILQ_INIT(&ci->ci_data.cpu_biodone);
ncpu++;
ncpuonline++;
return 0;
}
void
cpuctlattach(int dummy)
{
KASSERT(cpu_infos != NULL);
}
int
cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l)
{
CPU_INFO_ITERATOR cii;
cpustate_t *cs;
struct cpu_info *ci;
int error, i;
u_int id;
error = 0;
mutex_enter(&cpu_lock);
switch (cmd) {
case IOC_CPU_SETSTATE:
if (error == 0)
cs = data;
error = kauth_authorize_system(l->l_cred,
KAUTH_SYSTEM_CPU, KAUTH_REQ_SYSTEM_CPU_SETSTATE, cs, NULL,
NULL);
if (error != 0)
break;
if (cs->cs_id >= maxcpus ||
(ci = cpu_lookup(cs->cs_id)) == NULL) {
error = ESRCH;
break;
}
error = cpu_setintr(ci, cs->cs_intr);
error = cpu_setstate(ci, cs->cs_online);
break;
case IOC_CPU_GETSTATE:
if (error == 0)
cs = data;
id = cs->cs_id;
memset(cs, 0, sizeof(*cs));
cs->cs_id = id;
if (cs->cs_id >= maxcpus ||
(ci = cpu_lookup(id)) == NULL) {
error = ESRCH;
break;
}
if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0)
cs->cs_online = false;
else
cs->cs_online = true;
if ((ci->ci_schedstate.spc_flags & SPCF_NOINTR) != 0)
cs->cs_intr = false;
else
cs->cs_intr = true;
cs->cs_lastmod = (int32_t)ci->ci_schedstate.spc_lastmod;
cs->cs_lastmodhi = (int32_t)
(ci->ci_schedstate.spc_lastmod >> 32);
cs->cs_intrcnt = cpu_intr_count(ci) + 1;
break;
case IOC_CPU_MAPID:
i = 0;
for (CPU_INFO_FOREACH(cii, ci)) {
if (i++ == *(int *)data)
break;
}
if (ci == NULL)
error = ESRCH;
else
*(int *)data = cpu_index(ci);
break;
case IOC_CPU_GETCOUNT:
*(int *)data = ncpu;
break;
default:
error = ENOTTY;
break;
}
mutex_exit(&cpu_lock);
return error;
}
struct cpu_info *
cpu_lookup(u_int idx)
{
struct cpu_info *ci;
KASSERT(idx < maxcpus);
if (__predict_false(cpu_infos == NULL)) {
KASSERT(idx == 0);
return curcpu();
}
ci = cpu_infos[idx];
KASSERT(ci == NULL || cpu_index(ci) == idx);
return ci;
}
static void
cpu_xc_offline(struct cpu_info *ci)
{
struct schedstate_percpu *spc, *mspc = NULL;
struct cpu_info *target_ci;
struct lwp *l;
CPU_INFO_ITERATOR cii;
int s;
/*
* Thread that made the cross call (separate context) holds
* cpu_lock on our behalf.
*/
spc = &ci->ci_schedstate;
s = splsched();
spc->spc_flags |= SPCF_OFFLINE;
splx(s);
/* Take the first available CPU for the migration. */
for (CPU_INFO_FOREACH(cii, target_ci)) {
mspc = &target_ci->ci_schedstate;
if ((mspc->spc_flags & SPCF_OFFLINE) == 0)
break;
}
KASSERT(target_ci != NULL);
/*
* Migrate all non-bound threads to the other CPU. Note that this
* runs from the xcall thread, thus handling of LSONPROC is not needed.
*/
mutex_enter(proc_lock);
LIST_FOREACH(l, &alllwp, l_list) {
struct cpu_info *mci;
lwp_lock(l);
if (l->l_cpu != ci || (l->l_pflag & (LP_BOUND | LP_INTR))) {
lwp_unlock(l);
continue;
}
/* Regular case - no affinity. */
if (l->l_affinity == NULL) {
lwp_migrate(l, target_ci);
continue;
}
/* Affinity is set, find an online CPU in the set. */
for (CPU_INFO_FOREACH(cii, mci)) {
mspc = &mci->ci_schedstate;
if ((mspc->spc_flags & SPCF_OFFLINE) == 0 &&
kcpuset_isset(l->l_affinity, cpu_index(mci)))
break;
}
if (mci == NULL) {
lwp_unlock(l);
mutex_exit(proc_lock);
goto fail;
}
lwp_migrate(l, mci);
}
mutex_exit(proc_lock);
#ifdef __HAVE_MD_CPU_OFFLINE
cpu_offline_md();
#endif
return;
fail:
/* Just unset the SPCF_OFFLINE flag, caller will check */
s = splsched();
spc->spc_flags &= ~SPCF_OFFLINE;
splx(s);
}
static void
cpu_xc_online(struct cpu_info *ci)
{
struct schedstate_percpu *spc;
int s;
spc = &ci->ci_schedstate;
s = splsched();
spc->spc_flags &= ~SPCF_OFFLINE;
splx(s);
}
int
cpu_setstate(struct cpu_info *ci, bool online)
{
struct schedstate_percpu *spc;
CPU_INFO_ITERATOR cii;
struct cpu_info *ci2;
uint64_t where;
xcfunc_t func;
int nonline;
spc = &ci->ci_schedstate;
KASSERT(mutex_owned(&cpu_lock));
if (online) {
if ((spc->spc_flags & SPCF_OFFLINE) == 0)
return 0;
func = (xcfunc_t)cpu_xc_online;
ncpuonline++;
} else {
if ((spc->spc_flags & SPCF_OFFLINE) != 0)
return 0;
nonline = 0;
/*
* Ensure that at least one CPU within the processor set
* stays online. Revisit this later.
*/
for (CPU_INFO_FOREACH(cii, ci2)) {
if ((ci2->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0)
continue;
if (ci2->ci_schedstate.spc_psid != spc->spc_psid)
continue;
nonline++;
}
if (nonline == 1)
return EBUSY;
func = (xcfunc_t)cpu_xc_offline;
ncpuonline--;
}
where = xc_unicast(0, func, ci, NULL, ci);
xc_wait(where);
if (online) {
KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0);
} else if ((spc->spc_flags & SPCF_OFFLINE) == 0) {
/* If was not set offline, then it is busy */
return EBUSY;
}
spc->spc_lastmod = time_second;
return 0;
}
#ifdef __HAVE_INTR_CONTROL
static void
cpu_xc_intr(struct cpu_info *ci)
{
struct schedstate_percpu *spc;
int s;
spc = &ci->ci_schedstate;
s = splsched();
spc->spc_flags &= ~SPCF_NOINTR;
splx(s);
}
static void
cpu_xc_nointr(struct cpu_info *ci)
{
struct schedstate_percpu *spc;
int s;
spc = &ci->ci_schedstate;
s = splsched();
spc->spc_flags |= SPCF_NOINTR;
splx(s);
}
int
cpu_setintr(struct cpu_info *ci, bool intr)
{
struct schedstate_percpu *spc;
CPU_INFO_ITERATOR cii;
struct cpu_info *ci2;
uint64_t where;
xcfunc_t func;
int nintr;
spc = &ci->ci_schedstate;
KASSERT(mutex_owned(&cpu_lock));
if (intr) {
if ((spc->spc_flags & SPCF_NOINTR) == 0)
return 0;
func = (xcfunc_t)cpu_xc_intr;
} else {
if ((spc->spc_flags & SPCF_NOINTR) != 0)
return 0;
/*
* Ensure that at least one CPU within the system
* is handing device interrupts.
*/
nintr = 0;
for (CPU_INFO_FOREACH(cii, ci2)) {
if ((ci2->ci_schedstate.spc_flags & SPCF_NOINTR) != 0)
continue;
if (ci2 == ci)
continue;
nintr++;
}
if (nintr == 0)
return EBUSY;
func = (xcfunc_t)cpu_xc_nointr;
}
where = xc_unicast(0, func, ci, NULL, ci);
xc_wait(where);
if (intr) {
KASSERT((spc->spc_flags & SPCF_NOINTR) == 0);
} else if ((spc->spc_flags & SPCF_NOINTR) == 0) {
/* If was not set offline, then it is busy */
return EBUSY;
}
/* Direct interrupts away from the CPU and record the change. */
cpu_intr_redistribute();
spc->spc_lastmod = time_second;
return 0;
}
#else /* __HAVE_INTR_CONTROL */
int
cpu_setintr(struct cpu_info *ci, bool intr)
{
return EOPNOTSUPP;
}
u_int
cpu_intr_count(struct cpu_info *ci)
{
return 0; /* 0 == "don't know" */
}
#endif /* __HAVE_INTR_CONTROL */
bool
cpu_softintr_p(void)
{
return (curlwp->l_pflag & LP_INTR) != 0;
}