File: [local] / sys / kern / kern_lock.c (download)
Revision 1.1.1.1 (vendor branch), Tue Mar 4 16:14:53 2008 UTC (16 years, 4 months ago) by nbrk
Branch: OPENBSD_4_2_BASE, MAIN
CVS Tags: jornada-partial-support-wip, HEAD Changes since 1.1: +0 -0 lines
Import of OpenBSD 4.2 release kernel tree with initial code to support
Jornada 720/728, StrongARM 1110-based handheld PC.
At this point kernel roots on NFS and boots into vfs_mountroot() and traps.
What is supported:
- glass console, Jornada framebuffer (jfb) works in 16bpp direct color mode
(needs some palette tweaks for non black/white/blue colors, i think)
- saic, SA11x0 interrupt controller (needs cleanup)
- sacom, SA11x0 UART (supported only as boot console for now)
- SA11x0 GPIO controller fully supported (but can't handle multiple interrupt
handlers on one gpio pin)
- sassp, SSP port on SA11x0 that attaches spibus
- Jornada microcontroller (jmcu) to control kbd, battery, etc throught
the SPI bus (wskbd attaches on jmcu, but not tested)
- tod functions seem work
- initial code for SA-1111 (chip companion) : this is TODO
Next important steps, i think:
- gpio and intc on sa1111
- pcmcia support for sa11x0 (and sa1111 help logic)
- REAL root on nfs when we have PCMCIA support (we may use any of supported pccard NICs)
- root on wd0! (using already supported PCMCIA-ATA)
|
/* $OpenBSD: kern_lock.c,v 1.30 2007/05/31 22:07:53 thib Exp $ */
/*
* Copyright (c) 1995
* The Regents of the University of California. All rights reserved.
*
* This code contains ideas from software contributed to Berkeley by
* Avadis Tevanian, Jr., Michael Wayne Young, and the Mach Operating
* System project at Carnegie-Mellon University.
*
* 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. 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.
*
* @(#)kern_lock.c 8.18 (Berkeley) 5/21/95
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/systm.h>
#include <sys/sched.h>
#include <machine/cpu.h>
#ifndef spllock
#define spllock() splhigh()
#endif
#ifdef MULTIPROCESSOR
#define CPU_NUMBER() cpu_number()
#else
#define CPU_NUMBER() 0
#endif
void record_stacktrace(int *, int);
void playback_stacktrace(int *, int);
/*
* Locking primitives implementation.
* Locks provide shared/exclusive synchronization.
*/
#ifdef DDB /* { */
#ifdef MULTIPROCESSOR
int simple_lock_debugger = 1; /* more serious on MP */
#else
int simple_lock_debugger = 0;
#endif
#define SLOCK_DEBUGGER() if (simple_lock_debugger) Debugger()
#define SLOCK_TRACE() \
db_stack_trace_print((db_expr_t)__builtin_frame_address(0), \
TRUE, 65535, "", lock_printf);
#else
#define SLOCK_DEBUGGER() /* nothing */
#define SLOCK_TRACE() /* nothing */
#endif /* } */
/*
* Acquire a resource.
*/
#define ACQUIRE(lkp, error, extflags, drain, wanted) \
do { \
for (error = 0; wanted; ) { \
if ((drain)) \
(lkp)->lk_flags |= LK_WAITDRAIN; \
else \
(lkp)->lk_waitcount++; \
/* XXX Cast away volatile. */ \
error = tsleep((drain) ? \
(void *)&(lkp)->lk_flags : (void *)(lkp), \
(lkp)->lk_prio, (lkp)->lk_wmesg, (lkp)->lk_timo); \
if ((drain) == 0) \
(lkp)->lk_waitcount--; \
if (error) \
break; \
if ((extflags) & LK_SLEEPFAIL) { \
error = ENOLCK; \
break; \
} \
} \
} while (0)
#define SETHOLDER(lkp, pid, cpu_id) \
(lkp)->lk_lockholder = (pid)
#define WEHOLDIT(lkp, pid, cpu_id) \
(lkp)->lk_lockholder == (pid)
#define WAKEUP_WAITER(lkp) \
do { \
if ((lkp)->lk_waitcount) { \
/* XXX Cast away volatile. */ \
wakeup((void *)(lkp)); \
} \
} while (/*CONSTCOND*/0)
#if defined(LOCKDEBUG) /* { */
#if defined(MULTIPROCESSOR) /* { */
struct simplelock spinlock_list_slock = SIMPLELOCK_INITIALIZER;
#define SPINLOCK_LIST_LOCK() \
__cpu_simple_lock(&spinlock_list_slock.lock_data)
#define SPINLOCK_LIST_UNLOCK() \
__cpu_simple_unlock(&spinlock_list_slock.lock_data)
#else
#define SPINLOCK_LIST_LOCK() /* nothing */
#define SPINLOCK_LIST_UNLOCK() /* nothing */
#endif /* MULTIPROCESSOR */ /* } */
TAILQ_HEAD(, lock) spinlock_list =
TAILQ_HEAD_INITIALIZER(spinlock_list);
#endif /* LOCKDEBUG */ /* } */
#define HAVEIT(lkp) \
do { \
} while (/*CONSTCOND*/0)
#define DONTHAVEIT(lkp) \
do { \
} while (/*CONSTCOND*/0)
#if defined(LOCKDEBUG)
/*
* Lock debug printing routine; can be configured to print to console
* or log to syslog.
*/
void
lock_printf(const char *fmt, ...)
{
char b[150];
va_list ap;
va_start(ap, fmt);
if (lock_debug_syslog)
vlog(LOG_DEBUG, fmt, ap);
else {
vsnprintf(b, sizeof(b), fmt, ap);
printf_nolog("%s", b);
}
va_end(ap);
}
#endif /* LOCKDEBUG */
/*
* Initialize a lock; required before use.
*/
void
lockinit(struct lock *lkp, int prio, char *wmesg, int timo, int flags)
{
bzero(lkp, sizeof(struct lock));
lkp->lk_flags = flags & LK_EXTFLG_MASK;
lkp->lk_lockholder = LK_NOPROC;
lkp->lk_prio = prio;
lkp->lk_timo = timo;
lkp->lk_wmesg = wmesg; /* just a name for spin locks */
#if defined(LOCKDEBUG)
lkp->lk_lock_file = NULL;
lkp->lk_unlock_file = NULL;
#endif
}
/*
* Determine the status of a lock.
*/
int
lockstatus(struct lock *lkp)
{
int lock_type = 0;
if (lkp->lk_exclusivecount != 0)
lock_type = LK_EXCLUSIVE;
else if (lkp->lk_sharecount != 0)
lock_type = LK_SHARED;
return (lock_type);
}
/*
* Set, change, or release a lock.
*
* Shared requests increment the shared count. Exclusive requests set the
* LK_WANT_EXCL flag (preventing further shared locks), and wait for already
* accepted shared locks and shared-to-exclusive upgrades to go away.
*/
int
lockmgr(__volatile struct lock *lkp, u_int flags, struct simplelock *interlkp)
{
int error;
pid_t pid;
int extflags;
cpuid_t cpu_id;
struct proc *p = curproc;
error = 0;
extflags = (flags | lkp->lk_flags) & LK_EXTFLG_MASK;
#ifdef DIAGNOSTIC
if (p == NULL)
panic("lockmgr: process context required");
#endif
/* Process context required. */
pid = p->p_pid;
cpu_id = CPU_NUMBER();
/*
* Once a lock has drained, the LK_DRAINING flag is set and an
* exclusive lock is returned. The only valid operation thereafter
* is a single release of that exclusive lock. This final release
* clears the LK_DRAINING flag and sets the LK_DRAINED flag. Any
* further requests of any sort will result in a panic. The bits
* selected for these two flags are chosen so that they will be set
* in memory that is freed (freed memory is filled with 0xdeadbeef).
*/
if (lkp->lk_flags & (LK_DRAINING|LK_DRAINED)) {
#ifdef DIAGNOSTIC
if (lkp->lk_flags & LK_DRAINED)
panic("lockmgr: using decommissioned lock");
if ((flags & LK_TYPE_MASK) != LK_RELEASE ||
WEHOLDIT(lkp, pid, cpu_id) == 0)
panic("lockmgr: non-release on draining lock: %d",
flags & LK_TYPE_MASK);
#endif /* DIAGNOSTIC */
lkp->lk_flags &= ~LK_DRAINING;
lkp->lk_flags |= LK_DRAINED;
}
/*
* Check if the caller is asking us to be schizophrenic.
*/
if ((lkp->lk_flags & (LK_CANRECURSE|LK_RECURSEFAIL)) ==
(LK_CANRECURSE|LK_RECURSEFAIL))
panic("lockmgr: make up your mind");
switch (flags & LK_TYPE_MASK) {
case LK_SHARED:
if (WEHOLDIT(lkp, pid, cpu_id) == 0) {
/*
* If just polling, check to see if we will block.
*/
if ((extflags & LK_NOWAIT) && (lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL))) {
error = EBUSY;
break;
}
/*
* Wait for exclusive locks and upgrades to clear.
*/
ACQUIRE(lkp, error, extflags, 0, lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL));
if (error)
break;
lkp->lk_sharecount++;
break;
}
/*
* We hold an exclusive lock, so downgrade it to shared.
* An alternative would be to fail with EDEADLK.
*/
lkp->lk_sharecount++;
if (WEHOLDIT(lkp, pid, cpu_id) == 0 ||
lkp->lk_exclusivecount == 0)
panic("lockmgr: not holding exclusive lock");
lkp->lk_sharecount += lkp->lk_exclusivecount;
lkp->lk_exclusivecount = 0;
lkp->lk_flags &= ~LK_HAVE_EXCL;
SETHOLDER(lkp, LK_NOPROC, LK_NOCPU);
#if defined(LOCKDEBUG)
lkp->lk_unlock_file = file;
lkp->lk_unlock_line = line;
#endif
DONTHAVEIT(lkp);
WAKEUP_WAITER(lkp);
break;
case LK_EXCLUSIVE:
if (WEHOLDIT(lkp, pid, cpu_id)) {
/*
* Recursive lock.
*/
if ((extflags & LK_CANRECURSE) == 0) {
if (extflags & LK_RECURSEFAIL) {
error = EDEADLK;
break;
} else
panic("lockmgr: locking against myself");
}
lkp->lk_exclusivecount++;
break;
}
/*
* If we are just polling, check to see if we will sleep.
*/
if ((extflags & LK_NOWAIT) && ((lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL)) ||
lkp->lk_sharecount != 0)) {
error = EBUSY;
break;
}
/*
* Try to acquire the want_exclusive flag.
*/
ACQUIRE(lkp, error, extflags, 0, lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL));
if (error)
break;
lkp->lk_flags |= LK_WANT_EXCL;
/*
* Wait for shared locks and upgrades to finish.
*/
ACQUIRE(lkp, error, extflags, 0, lkp->lk_sharecount != 0);
lkp->lk_flags &= ~LK_WANT_EXCL;
if (error)
break;
lkp->lk_flags |= LK_HAVE_EXCL;
SETHOLDER(lkp, pid, cpu_id);
#if defined(LOCKDEBUG)
lkp->lk_lock_file = file;
lkp->lk_lock_line = line;
#endif
HAVEIT(lkp);
if (lkp->lk_exclusivecount != 0)
panic("lockmgr: non-zero exclusive count");
lkp->lk_exclusivecount = 1;
break;
case LK_RELEASE:
if (lkp->lk_exclusivecount != 0) {
if (WEHOLDIT(lkp, pid, cpu_id) == 0) {
panic("lockmgr: pid %d, not exclusive lock "
"holder %d unlocking",
pid, lkp->lk_lockholder);
}
lkp->lk_exclusivecount--;
if (lkp->lk_exclusivecount == 0) {
lkp->lk_flags &= ~LK_HAVE_EXCL;
SETHOLDER(lkp, LK_NOPROC, LK_NOCPU);
#if defined(LOCKDEBUG)
lkp->lk_unlock_file = file;
lkp->lk_unlock_line = line;
#endif
DONTHAVEIT(lkp);
}
} else if (lkp->lk_sharecount != 0) {
lkp->lk_sharecount--;
}
#ifdef DIAGNOSTIC
else
panic("lockmgr: release of unlocked lock!");
#endif
WAKEUP_WAITER(lkp);
break;
case LK_DRAIN:
/*
* Check that we do not already hold the lock, as it can
* never drain if we do. Unfortunately, we have no way to
* check for holding a shared lock, but at least we can
* check for an exclusive one.
*/
if (WEHOLDIT(lkp, pid, cpu_id))
panic("lockmgr: draining against myself");
/*
* If we are just polling, check to see if we will sleep.
*/
if ((extflags & LK_NOWAIT) && ((lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL)) ||
lkp->lk_sharecount != 0 || lkp->lk_waitcount != 0)) {
error = EBUSY;
break;
}
ACQUIRE(lkp, error, extflags, 1,
((lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL)) ||
lkp->lk_sharecount != 0 ||
lkp->lk_waitcount != 0));
if (error)
break;
lkp->lk_flags |= LK_DRAINING | LK_HAVE_EXCL;
SETHOLDER(lkp, pid, cpu_id);
#if defined(LOCKDEBUG)
lkp->lk_lock_file = file;
lkp->lk_lock_line = line;
#endif
HAVEIT(lkp);
lkp->lk_exclusivecount = 1;
break;
default:
panic("lockmgr: unknown locktype request %d",
flags & LK_TYPE_MASK);
/* NOTREACHED */
}
if ((lkp->lk_flags & LK_WAITDRAIN) != 0 &&
((lkp->lk_flags &
(LK_HAVE_EXCL | LK_WANT_EXCL)) == 0 &&
lkp->lk_sharecount == 0 && lkp->lk_waitcount == 0)) {
lkp->lk_flags &= ~LK_WAITDRAIN;
wakeup((void *)&lkp->lk_flags);
}
return (error);
}
#ifdef DIAGNOSTIC
/*
* Print out information about state of a lock. Used by VOP_PRINT
* routines to display ststus about contained locks.
*/
void
lockmgr_printinfo(__volatile struct lock *lkp)
{
if (lkp->lk_sharecount)
printf(" lock type %s: SHARED (count %d)", lkp->lk_wmesg,
lkp->lk_sharecount);
else if (lkp->lk_flags & LK_HAVE_EXCL) {
printf(" lock type %s: EXCL (count %d) by ",
lkp->lk_wmesg, lkp->lk_exclusivecount);
printf("pid %d", lkp->lk_lockholder);
} else
printf(" not locked");
if (lkp->lk_waitcount > 0)
printf(" with %d pending", lkp->lk_waitcount);
}
#endif /* DIAGNOSTIC */
#if defined(LOCKDEBUG)
TAILQ_HEAD(, simplelock) simplelock_list =
TAILQ_HEAD_INITIALIZER(simplelock_list);
#if defined(MULTIPROCESSOR) /* { */
struct simplelock simplelock_list_slock = SIMPLELOCK_INITIALIZER;
#define SLOCK_LIST_LOCK() \
__cpu_simple_lock(&simplelock_list_slock.lock_data)
#define SLOCK_LIST_UNLOCK() \
__cpu_simple_unlock(&simplelock_list_slock.lock_data)
#define SLOCK_COUNT(x) \
curcpu()->ci_simple_locks += (x)
#else
u_long simple_locks;
#define SLOCK_LIST_LOCK() /* nothing */
#define SLOCK_LIST_UNLOCK() /* nothing */
#define SLOCK_COUNT(x) simple_locks += (x)
#endif /* MULTIPROCESSOR */ /* } */
#ifdef MULTIPROCESSOR
#define SLOCK_MP() lock_printf("on cpu %ld\n", \
(u_long) cpu_number())
#else
#define SLOCK_MP() /* nothing */
#endif
#define SLOCK_WHERE(str, alp, id, l) \
do { \
lock_printf("\n"); \
lock_printf(str); \
lock_printf("lock: %p, currently at: %s:%d\n", (alp), (id), (l)); \
SLOCK_MP(); \
if ((alp)->lock_file != NULL) \
lock_printf("last locked: %s:%d\n", (alp)->lock_file, \
(alp)->lock_line); \
if ((alp)->unlock_file != NULL) \
lock_printf("last unlocked: %s:%d\n", (alp)->unlock_file, \
(alp)->unlock_line); \
SLOCK_TRACE() \
SLOCK_DEBUGGER(); \
} while (/*CONSTCOND*/0)
/*
* Simple lock functions so that the debugger can see from whence
* they are being called.
*/
void
simple_lock_init(struct simplelock *lkp)
{
#if defined(MULTIPROCESSOR) /* { */
__cpu_simple_lock_init(&alp->lock_data);
#else
alp->lock_data = __SIMPLELOCK_UNLOCKED;
#endif /* } */
alp->lock_file = NULL;
alp->lock_line = 0;
alp->unlock_file = NULL;
alp->unlock_line = 0;
alp->lock_holder = LK_NOCPU;
}
void
_simple_lock(__volatile struct simplelock *lkp, const char *id, int l)
{
cpuid_t cpu_id = CPU_NUMBER();
int s;
s = spllock();
/*
* MULTIPROCESSOR case: This is `safe' since if it's not us, we
* don't take any action, and just fall into the normal spin case.
*/
if (alp->lock_data == __SIMPLELOCK_LOCKED) {
#if defined(MULTIPROCESSOR) /* { */
if (alp->lock_holder == cpu_id) {
SLOCK_WHERE("simple_lock: locking against myself\n",
alp, id, l);
goto out;
}
#else
SLOCK_WHERE("simple_lock: lock held\n", alp, id, l);
goto out;
#endif /* MULTIPROCESSOR */ /* } */
}
#if defined(MULTIPROCESSOR) /* { */
/* Acquire the lock before modifying any fields. */
splx(s);
__cpu_simple_lock(&alp->lock_data);
s = spllock();
#else
alp->lock_data = __SIMPLELOCK_LOCKED;
#endif /* } */
if (alp->lock_holder != LK_NOCPU) {
SLOCK_WHERE("simple_lock: uninitialized lock\n",
alp, id, l);
}
alp->lock_file = id;
alp->lock_line = l;
alp->lock_holder = cpu_id;
SLOCK_LIST_LOCK();
/* XXX Cast away volatile */
TAILQ_INSERT_TAIL(&simplelock_list, (struct simplelock *)alp, list);
SLOCK_LIST_UNLOCK();
SLOCK_COUNT(1);
out:
splx(s);
}
int
_simple_lock_held(__volatile struct simplelock *alp)
{
cpuid_t cpu_id = CPU_NUMBER();
int s, locked = 0;
s = spllock();
#if defined(MULTIPROCESSOR)
if (__cpu_simple_lock_try(&alp->lock_data) == 0)
locked = (alp->lock_holder == cpu_id);
else
__cpu_simple_unlock(&alp->lock_data);
#else
if (alp->lock_data == __SIMPLELOCK_LOCKED) {
locked = 1;
KASSERT(alp->lock_holder == cpu_id);
}
#endif
splx(s);
return (locked);
}
int
_simple_lock_try(__volatile struct simplelock *lkp, const char *id, int l)
{
cpuid_t cpu_id = CPU_NUMBER();
int s, rv = 0;
s = spllock();
/*
* MULTIPROCESSOR case: This is `safe' since if it's not us, we
* don't take any action.
*/
#if defined(MULTIPROCESSOR) /* { */
if ((rv = __cpu_simple_lock_try(&alp->lock_data)) == 0) {
if (alp->lock_holder == cpu_id)
SLOCK_WHERE("simple_lock_try: locking against myself\n",
alp, id, l);
goto out;
}
#else
if (alp->lock_data == __SIMPLELOCK_LOCKED) {
SLOCK_WHERE("simple_lock_try: lock held\n", alp, id, l);
goto out;
}
alp->lock_data = __SIMPLELOCK_LOCKED;
#endif /* MULTIPROCESSOR */ /* } */
/*
* At this point, we have acquired the lock.
*/
rv = 1;
alp->lock_file = id;
alp->lock_line = l;
alp->lock_holder = cpu_id;
SLOCK_LIST_LOCK();
/* XXX Cast away volatile. */
TAILQ_INSERT_TAIL(&simplelock_list, (struct simplelock *)alp, list);
SLOCK_LIST_UNLOCK();
SLOCK_COUNT(1);
out:
splx(s);
return (rv);
}
void
_simple_unlock(__volatile struct simplelock *lkp, const char *id, int l)
{
int s;
s = spllock();
/*
* MULTIPROCESSOR case: This is `safe' because we think we hold
* the lock, and if we don't, we don't take any action.
*/
if (alp->lock_data == __SIMPLELOCK_UNLOCKED) {
SLOCK_WHERE("simple_unlock: lock not held\n",
alp, id, l);
goto out;
}
SLOCK_LIST_LOCK();
TAILQ_REMOVE(&simplelock_list, alp, list);
SLOCK_LIST_UNLOCK();
SLOCK_COUNT(-1);
alp->list.tqe_next = NULL; /* sanity */
alp->list.tqe_prev = NULL; /* sanity */
alp->unlock_file = id;
alp->unlock_line = l;
#if defined(MULTIPROCESSOR) /* { */
alp->lock_holder = LK_NOCPU;
/* Now that we've modified all fields, release the lock. */
__cpu_simple_unlock(&alp->lock_data);
#else
alp->lock_data = __SIMPLELOCK_UNLOCKED;
KASSERT(alp->lock_holder == CPU_NUMBER());
alp->lock_holder = LK_NOCPU;
#endif /* } */
out:
splx(s);
}
void
simple_lock_dump(void)
{
struct simplelock *alp;
int s;
s = spllock();
SLOCK_LIST_LOCK();
lock_printf("all simple locks:\n");
TAILQ_FOREACH(alp, &simplelock_list, list) {
lock_printf("%p CPU %lu %s:%d\n", alp, alp->lock_holder,
alp->lock_file, alp->lock_line);
}
SLOCK_LIST_UNLOCK();
splx(s);
}
void
simple_lock_freecheck(void *start, void *end)
{
struct simplelock *alp;
int s;
s = spllock();
SLOCK_LIST_LOCK();
TAILQ_FOREACH(alp, &simplelock_list, list) {
if ((void *)alp >= start && (void *)alp < end) {
lock_printf("freeing simple_lock %p CPU %lu %s:%d\n",
alp, alp->lock_holder, alp->lock_file,
alp->lock_line);
SLOCK_DEBUGGER();
}
}
SLOCK_LIST_UNLOCK();
splx(s);
}
/*
* We must be holding exactly one lock: the sched_lock.
*/
#ifdef notyet
void
simple_lock_switchcheck(void)
{
simple_lock_only_held(&sched_lock, "switching");
}
#endif
void
simple_lock_only_held(volatile struct simplelock *lp, const char *where)
{
struct simplelock *alp;
cpuid_t cpu_id = CPU_NUMBER();
int s;
if (lp) {
LOCK_ASSERT(simple_lock_held(lp));
}
s = spllock();
SLOCK_LIST_LOCK();
TAILQ_FOREACH(alp, &simplelock_list, list) {
if (alp == lp)
continue;
if (alp->lock_holder == cpu_id)
break;
}
SLOCK_LIST_UNLOCK();
splx(s);
if (alp != NULL) {
lock_printf("\n%s with held simple_lock %p "
"CPU %lu %s:%d\n",
where, alp, alp->lock_holder, alp->lock_file,
alp->lock_line);
SLOCK_TRACE();
SLOCK_DEBUGGER();
}
}
#endif /* LOCKDEBUG */
#if defined(MULTIPROCESSOR)
/*
* Functions for manipulating the kernel_lock. We put them here
* so that they show up in profiles.
*/
struct __mp_lock kernel_lock;
void
_kernel_lock_init(void)
{
__mp_lock_init(&kernel_lock);
}
/*
* Acquire/release the kernel lock. Intended for use in the scheduler
* and the lower half of the kernel.
*/
void
_kernel_lock(void)
{
SCHED_ASSERT_UNLOCKED();
__mp_lock(&kernel_lock);
}
void
_kernel_unlock(void)
{
__mp_unlock(&kernel_lock);
}
/*
* Acquire/release the kernel_lock on behalf of a process. Intended for
* use in the top half of the kernel.
*/
void
_kernel_proc_lock(struct proc *p)
{
SCHED_ASSERT_UNLOCKED();
__mp_lock(&kernel_lock);
atomic_setbits_int(&p->p_flag, P_BIGLOCK);
}
void
_kernel_proc_unlock(struct proc *p)
{
atomic_clearbits_int(&p->p_flag, P_BIGLOCK);
__mp_unlock(&kernel_lock);
}
#ifdef MP_LOCKDEBUG
/* CPU-dependent timing, needs this to be settable from ddb. */
int __mp_lock_spinout = 200000000;
#endif
#endif /* MULTIPROCESSOR */