+++ /dev/null
-/* $OpenBSD: lock_machdep.c,v 1.9 2024/07/03 01:36:50 jsg Exp $ */
-
-/*
- * Copyright (c) 2007 Artur Grabowski <art@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-
-#include <sys/param.h>
-#include <sys/systm.h>
-
-#include <machine/atomic.h>
-#include <machine/cpu.h>
-
-#if defined(MP_LOCKDEBUG)
-#ifndef DDB
-#error "MP_LOCKDEBUG requires DDB"
-#endif
-#include <ddb/db_output.h>
-
-/* CPU-dependent timing, needs this to be settable from ddb. */
-extern int __mp_lock_spinout;
-#endif
-
-static inline int
-__cpu_cas(volatile unsigned long *addr, unsigned long old, unsigned long new)
-{
- unsigned long t0, v0;
-
- __asm volatile(
- "1: ldq_l %1, 0(%2) \n" /* v0 = *addr */
- " cmpeq %1, %3, %0 \n" /* t0 = v0 == old */
- " beq %0, 2f \n"
- " mov %4, %0 \n" /* t0 = new */
- " stq_c %0, 0(%2) \n" /* *addr = new */
- " beq %0, 3f \n"
- " mb \n"
- "2: br 4f \n"
- "3: br 1b \n" /* update failed */
- "4: \n"
- : "=&r" (t0), "=&r" (v0)
- : "r" (addr), "r" (old), "r" (new)
- : "memory");
-
- return (v0 != old);
-}
-
-void
-__mp_lock_init(struct __mp_lock *lock)
-{
- lock->mpl_cpu = NULL;
- lock->mpl_count = 0;
-}
-
-static inline void
-__mp_lock_spin(struct __mp_lock *mpl)
-{
-#ifndef MP_LOCKDEBUG
- while (mpl->mpl_count != 0)
- CPU_BUSY_CYCLE();
-#else
- int nticks = __mp_lock_spinout;
- if (!CPU_IS_PRIMARY(curcpu()))
- nticks += nticks;
-
- while (mpl->mpl_count != 0 && --nticks > 0)
- CPU_BUSY_CYCLE();
-
- if (nticks == 0) {
- db_printf("__mp_lock(%p): lock spun out\n", mpl);
- db_enter();
- }
-#endif
-}
-
-void
-__mp_lock(struct __mp_lock *mpl)
-{
- int s;
- struct cpu_info *ci = curcpu();
-
- /*
- * Please notice that mpl_count gets incremented twice for the
- * first lock. This is on purpose. The way we release the lock
- * in mp_unlock is to decrement the mpl_count and then check if
- * the lock should be released. Since mpl_count is what we're
- * spinning on, decrementing it in mpl_unlock to 0 means that
- * we can't clear mpl_cpu, because we're no longer holding the
- * lock. In theory mpl_cpu doesn't need to be cleared, but it's
- * safer to clear it and besides, setting mpl_count to 2 on the
- * first lock makes most of this code much simpler.
- */
- while (1) {
- s = splhigh();
- if (__cpu_cas(&mpl->mpl_count, 0, 1) == 0) {
- alpha_mb();
- mpl->mpl_cpu = ci;
- }
-
- if (mpl->mpl_cpu == ci) {
- mpl->mpl_count++;
- splx(s);
- break;
- }
- splx(s);
-
- __mp_lock_spin(mpl);
- }
-}
-
-void
-__mp_unlock(struct __mp_lock *mpl)
-{
- int s;
-
-#ifdef MP_LOCKDEBUG
- if (mpl->mpl_cpu != curcpu()) {
- db_printf("__mp_unlock(%p): not held lock\n", mpl);
- db_enter();
- }
-#endif
-
- s = splhigh();
- if (--mpl->mpl_count == 1) {
- mpl->mpl_cpu = NULL;
- alpha_mb();
- mpl->mpl_count = 0;
- }
- splx(s);
-}
-
-int
-__mp_release_all(struct __mp_lock *mpl)
-{
- int rv = mpl->mpl_count - 1;
- int s;
-
-#ifdef MP_LOCKDEBUG
- if (mpl->mpl_cpu != curcpu()) {
- db_printf("__mp_release_all(%p): not held lock\n", mpl);
- db_enter();
- }
-#endif
-
- s = splhigh();
- mpl->mpl_cpu = NULL;
- alpha_mb();
- mpl->mpl_count = 0;
- splx(s);
-
- return (rv);
-}
-
-void
-__mp_acquire_count(struct __mp_lock *mpl, int count)
-{
- while (count--)
- __mp_lock(mpl);
-}
-
-int
-__mp_lock_held(struct __mp_lock *mpl, struct cpu_info *ci)
-{
- return (mpl->mpl_cpu == ci);
-}
-/* $OpenBSD: mplock.h,v 1.3 2024/07/03 01:36:50 jsg Exp $ */
+/* $OpenBSD: mplock.h,v 1.4 2024/08/23 18:45:28 miod Exp $ */
-/*
- * Copyright (c) 2004 Niklas Hallqvist. 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 ``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 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.
- */
+/* public domain */
#ifndef _MACHINE_MPLOCK_H_
#define _MACHINE_MPLOCK_H_
-/*
- * Really simple spinlock implementation with recursive capabilities.
- * Correctness is paramount, no fancyness allowed.
- */
-
-struct __mp_lock {
- volatile struct cpu_info *mpl_cpu;
- volatile long mpl_count;
-};
-
-#ifndef _LOCORE
-
-void __mp_lock_init(struct __mp_lock *);
-void __mp_lock(struct __mp_lock *);
-void __mp_unlock(struct __mp_lock *);
-int __mp_release_all(struct __mp_lock *);
-void __mp_acquire_count(struct __mp_lock *, int);
-int __mp_lock_held(struct __mp_lock *, struct cpu_info *);
-
-#endif
+#define __USE_MI_MPLOCK
#endif /* !_MACHINE_MPLOCK_H */
projects / openbsd / commitdiff