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Use spllock() rather than splhigh().

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This commit is contained in:
thorpej 2000-08-22 19:47:26 +00:00
parent 58e7a6954b
commit 7508bd7231
1 changed files with 40 additions and 11 deletions
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51
sys/kern/kern_lock.c
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@ -1,4 +1,4 @@
/* $NetBSD: kern_lock.c,v 1.43 2000/08/22 17:31:32 thorpej Exp $ */
/* $NetBSD: kern_lock.c,v 1.44 2000/08/22 19:47:26 thorpej Exp $ */
/*-
* Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
@ -241,7 +241,7 @@ TAILQ_HEAD(, lock) spinlock_list =
#define HAVEIT(lkp) \
do { \
if ((lkp)->lk_flags & LK_SPIN) { \
int s = splhigh(); \
int s = spllock(); \
SPINLOCK_LIST_LOCK(); \
/* XXX Cast away volatile. */ \
TAILQ_INSERT_TAIL(&spinlock_list, (struct lock *)(lkp), \
@ -254,7 +254,7 @@ do { \
#define DONTHAVEIT(lkp) \
do { \
if ((lkp)->lk_flags & LK_SPIN) { \
int s = splhigh(); \
int s = spllock(); \
SPINLOCK_LIST_LOCK(); \
/* XXX Cast away volatile. */ \
TAILQ_REMOVE(&spinlock_list, (struct lock *)(lkp), \
@ -336,7 +336,7 @@ spinlock_switchcheck(void)
u_long cnt;
int s;
s = splhigh();
s = spllock();
#if defined(MULTIPROCESSOR)
cnt = curcpu()->ci_spin_locks;
#else
@ -350,6 +350,35 @@ spinlock_switchcheck(void)
}
#endif /* LOCKDEBUG || DIAGNOSTIC */
/*
* Locks and IPLs (interrupt priority levels):
*
* Locks which may be taken from interrupt context must be handled
* very carefully; you must spl to the highest IPL where the lock
* is needed before acquiring the lock.
*
* It is also important to avoid deadlock, since certain (very high
* priority) interrupts are often needed to keep the system as a whole
* from deadlocking, and must not be blocked while you are spinning
* waiting for a lower-priority lock.
*
* In addition, the lock-debugging hooks themselves need to use locks!
*
* A raw __cpu_simple_lock may be used from interrupts are long as it
* is acquired and held at a single IPL.
*
* A simple_lock (which is a __cpu_simple_lock wrapped with some
* debugging hooks) may be used at or below spllock(), which is
* typically at or just below splhigh() (i.e. blocks everything
* but certain machine-dependent extremely high priority interrupts).
*
* spinlockmgr spinlocks should be used at or below splsched().
*
* Some platforms may have interrupts of higher priority than splsched(),
* including hard serial interrupts, inter-processor interrupts, and
* kernel debugger traps.
*/
/*
* XXX XXX kludge around another kludge..
*
@ -811,7 +840,7 @@ _simple_lock(__volatile struct simplelock *alp, const char *id, int l)
cpuid_t cpu_id = cpu_number();
int s;
s = splhigh();
s = spllock();
/*
* MULTIPROCESSOR case: This is `safe' since if it's not us, we
@ -860,7 +889,7 @@ _simple_lock_held(__volatile struct simplelock *alp)
cpuid_t cpu_id = cpu_number();
int s, locked = 0;
s = splhigh();
s = spllock();
#if defined(MULTIPROCESSOR)
if (__cpu_simple_lock_try(&alp->lock_data) == 0)
@ -885,7 +914,7 @@ _simple_lock_try(__volatile struct simplelock *alp, const char *id, int l)
cpuid_t cpu_id = cpu_number();
int s, rv = 0;
s = splhigh();
s = spllock();
/*
* MULTIPROCESSOR case: This is `safe' since if it's not us, we
@ -933,7 +962,7 @@ _simple_unlock(__volatile struct simplelock *alp, const char *id, int l)
{
int s;
s = splhigh();
s = spllock();
/*
* MULTIPROCESSOR case: This is `safe' because we think we hold
@ -977,7 +1006,7 @@ simple_lock_dump(void)
struct simplelock *alp;
int s;
s = splhigh();
s = spllock();
SLOCK_LIST_LOCK();
lock_printf("all simple locks:\n");
for (alp = TAILQ_FIRST(&simplelock_list); alp != NULL;
@ -995,7 +1024,7 @@ simple_lock_freecheck(void *start, void *end)
struct simplelock *alp;
int s;
s = splhigh();
s = spllock();
SLOCK_LIST_LOCK();
for (alp = TAILQ_FIRST(&simplelock_list); alp != NULL;
alp = TAILQ_NEXT(alp, list)) {
@ -1023,7 +1052,7 @@ simple_lock_switchcheck(void)
SCHED_ASSERT_LOCKED();
s = splhigh(); /* XXX spllock */
s = spllock();
SLOCK_LIST_LOCK();
for (alp = TAILQ_FIRST(&simplelock_list); alp != NULL;
alp = TAILQ_NEXT(alp, list)) {