Move the implementation of __mp_lock (biglock) into machine dependent

code. At this moment all architectures get the copy of the old code
except i386 which gets a new shiny implementation that doesn't spin
at splhigh (doh!) and doesn't try to grab the biglock when releasing
the biglock (double doh!).

Shaves 10% of system time during kernel compile and might solve a few
bugs as a bonus.

Other architectures coming shortly.

miod@ deraadt@ ok

1 files changed, 191 insertions, 0 deletions

diff --git a/sys/arch/macppc/include/mplock.h b/sys/arch/macppc/include/mplock.h
new file mode 100644
index 00000000000..8f87c895aae
--- /dev/null
+++ b/sys/arch/macppc/include/mplock.h
@@ -0,0 +1,191 @@
+/*	$OpenBSD: mplock.h,v 1.1 2007/11/26 17:15:29 art 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.
+ */
+
+#ifndef _MACHINE_MPLOCK_H_
+#define _MACHINE_MPLOCK_H_
+
+/*
+ * Really simple spinlock implementation with recursive capabilities.
+ * Correctness is paramount, no fancyness allowed.
+ */
+
+struct __mp_lock {
+	__cpu_simple_lock_t mpl_lock;
+	cpuid_t	mpl_cpu;
+	int	mpl_count;
+};
+
+static __inline void
+__mp_lock_init(struct __mp_lock *lock)
+{
+	__cpu_simple_lock_init(&lock->mpl_lock);
+	lock->mpl_cpu = LK_NOCPU;
+	lock->mpl_count = 0;
+}
+
+#if defined(MP_LOCKDEBUG)
+#ifndef DDB
+#error "MP_LOCKDEBUG requires DDB"
+#endif
+
+extern void Debugger(void);
+extern int db_printf(const char *, ...)
+    __attribute__((__format__(__kprintf__,1,2)));
+
+/* CPU-dependent timing, needs this to be settable from ddb. */
+extern int __mp_lock_spinout;
+#endif
+
+static __inline void
+__mp_lock(struct __mp_lock *lock)
+{
+	int s = spllock();
+
+	if (lock->mpl_cpu != cpu_number()) {
+#ifndef MP_LOCKDEBUG
+		__cpu_simple_lock(&lock->mpl_lock);
+#else
+		{
+			int got_it;
+			do {
+				int ticks = __mp_lock_spinout;
+
+				do {
+					got_it = __cpu_simple_lock_try(
+					    &lock->mpl_lock);
+				} while (!got_it && ticks-- > 0);
+				if (!got_it) {
+ 					db_printf(
+					    "__mp_lock(0x%x): lock spun out",
+					    lock);
+					Debugger();
+				}
+			} while (!got_it);
+		}
+#endif
+		lock->mpl_cpu = cpu_number();
+	}
+	lock->mpl_count++;
+	splx(s);
+}
+
+/*
+ * Try to acquire the lock, if another cpu has it, fill it in the
+ * call-by-reference cpu parameter.  Return true if acquired.
+ */
+static __inline int
+__mp_lock_try(struct __mp_lock *lock, cpuid_t *cpu)
+{
+	int s = spllock();
+
+	if (lock->mpl_cpu != cpu_number()) {
+		if (!__cpu_simple_lock_try(&lock->mpl_lock)) {
+			*cpu = lock->mpl_cpu;
+			splx(s);
+			return 0;
+		}
+		lock->mpl_cpu = cpu_number();
+	}
+	lock->mpl_count++;
+	splx(s);
+	return 1;
+}
+
+static __inline void
+__mp_unlock(struct __mp_lock *lock)
+{
+	int s = spllock();
+
+#ifdef MP_LOCKDEBUG
+	if (lock->mpl_count == 0 || lock->mpl_cpu == LK_NOCPU) {
+		db_printf("__mp_unlock(0x%x): releasing not locked lock\n",
+		    lock);
+		Debugger();
+	}
+#endif
+
+	if (--lock->mpl_count == 0) {
+		lock->mpl_cpu = LK_NOCPU;
+		__cpu_simple_unlock(&lock->mpl_lock);
+	}
+	splx(s);
+}
+
+static __inline int
+__mp_release_all(struct __mp_lock *lock) {
+	int s = spllock();
+	int rv = lock->mpl_count;
+
+#ifdef MP_LOCKDEBUG
+	if (lock->mpl_count == 0 || lock->mpl_cpu == LK_NOCPU) {
+		db_printf(
+		    "__mp_release_all(0x%x): releasing not locked lock\n",
+		    lock);
+		Debugger();
+	}
+#endif
+
+	lock->mpl_cpu = LK_NOCPU;
+	lock->mpl_count = 0;
+	__cpu_simple_unlock(&lock->mpl_lock);
+	splx(s);
+	return (rv);
+}
+
+static __inline int
+__mp_release_all_but_one(struct __mp_lock *lock) {
+	int s = spllock();
+	int rv = lock->mpl_count - 1;
+
+#ifdef MP_LOCKDEBUG
+	if (lock->mpl_count == 0 || lock->mpl_cpu == LK_NOCPU) {
+		db_printf(
+		    "__mp_release_all_but_one(0x%x): releasing not locked lock\n",
+		    lock);
+		Debugger();
+	}
+#endif
+
+	lock->mpl_count = 1;
+	splx(s);
+	return (rv);
+}
+
+static __inline void
+__mp_acquire_count(struct __mp_lock *lock, int count) {
+	int s = spllock();
+
+	while (count--)
+		__mp_lock(lock);
+	splx(s);
+}
+
+static __inline int
+__mp_lock_held(struct __mp_lock *lock) {
+	return lock->mpl_count && lock->mpl_cpu == cpu_number();
+}
+
+#endif /* !_MACHINE_MPLOCK_H */