replace the asm mutexes with a c implementation.

there's no real functional advantage to this, except that it will
make it easier to add deadlock detection to the code.

this is modelled on the c mutex implementation thats on alpha,
mips64, and hppa.

ok mpi@ kettenis@

7 files changed, 162 insertions, 199 deletions

diff --git a/sys/arch/macppc/macppc/genassym.cf b/sys/arch/macppc/macppc/genassym.cf
index ba2372e3749..8d95e9b4704 100644
--- a/sys/arch/macppc/macppc/genassym.cf
+++ b/sys/arch/macppc/macppc/genassym.cf
@@ -1,4 +1,4 @@
-#	$OpenBSD: genassym.cf,v 1.24 2014/09/06 10:45:29 mpi Exp $
+#	$OpenBSD: genassym.cf,v 1.25 2015/08/14 06:14:19 dlg Exp $
 #
 # Copyright (c) 1982, 1990 The Regents of the University of California.
 # All rights reserved.
@@ -97,8 +97,3 @@ member	ci_disisave
 ifdef DIAGNOSTIC
 member	ci_mutex_level
 endif
-
-struct	mutex
-member	mtx_wantipl
-member	mtx_oldcpl
-member	mtx_owner
diff --git a/sys/arch/powerpc/conf/files.powerpc b/sys/arch/powerpc/conf/files.powerpc
index 1394b63f07d..58212d1e670 100644
--- a/sys/arch/powerpc/conf/files.powerpc
+++ b/sys/arch/powerpc/conf/files.powerpc
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.powerpc,v 1.52 2015/07/17 22:52:29 tedu Exp $
+#	$OpenBSD: files.powerpc,v 1.53 2015/08/14 06:14:19 dlg Exp $
 #
 
 file	arch/powerpc/powerpc/setjmp.S			ddb
@@ -13,8 +13,8 @@ file	arch/powerpc/powerpc/process_machdep.c
 file	arch/powerpc/powerpc/sys_machdep.c
 file	arch/powerpc/powerpc/trap.c
 file	arch/powerpc/powerpc/vm_machdep.c
+file	arch/powerpc/powerpc/mutex.c
 file	arch/powerpc/powerpc/lock_machdep.c		multiprocessor
-file	arch/powerpc/powerpc/mutex.S
 file	arch/powerpc/powerpc/intr.c
 file	arch/powerpc/powerpc/softintr.c
 
diff --git a/sys/arch/powerpc/include/lock.h b/sys/arch/powerpc/include/lock.h
index 2d979d1d4fb..a533cbae429 100644
--- a/sys/arch/powerpc/include/lock.h
+++ b/sys/arch/powerpc/include/lock.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lock.h,v 1.6 2015/06/26 12:46:13 dlg Exp $	*/
+/*	$OpenBSD: lock.h,v 1.7 2015/08/14 06:14:19 dlg Exp $	*/
 /*	$NetBSD: lock.h,v 1.8 2005/12/28 19:09:29 perry Exp $	*/
 
 /*-
@@ -37,4 +37,6 @@
 #ifndef _POWERPC_LOCK_H_
 #define _POWERPC_LOCK_H_
 
+#define SPINLOCK_SPIN_HOOK do { } while (0)
+
 #endif /* _POWERPC_LOCK_H_ */
diff --git a/sys/arch/powerpc/include/mutex.h b/sys/arch/powerpc/include/mutex.h
index 6dec10b9b6b..8f6f2f1d57b 100644
--- a/sys/arch/powerpc/include/mutex.h
+++ b/sys/arch/powerpc/include/mutex.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mutex.h,v 1.4 2014/03/29 18:09:30 guenther Exp $	*/
+/*	$OpenBSD: mutex.h,v 1.5 2015/08/14 06:14:19 dlg Exp $	*/
 
 /*
  * Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
@@ -28,9 +28,9 @@
 #define _POWERPC_MUTEX_H_
 
 struct mutex {
-	int mtx_wantipl;
-	int mtx_oldcpl;
 	volatile void *mtx_owner;
+	int mtx_wantipl;
+	int mtx_oldipl;
 };
 
 /*
@@ -47,7 +47,7 @@ struct mutex {
 #define __MUTEX_IPL(ipl) (ipl)
 #endif
 
-#define MUTEX_INITIALIZER(ipl) { __MUTEX_IPL((ipl)), 0, NULL }
+#define MUTEX_INITIALIZER(ipl) { NULL, __MUTEX_IPL(ipl), IPL_NONE }
 
 void __mtx_init(struct mutex *, int);
 #define mtx_init(mtx, ipl) __mtx_init((mtx), __MUTEX_IPL((ipl)))
@@ -67,6 +67,6 @@ void __mtx_init(struct mutex *, int);
 #define MUTEX_ASSERT_UNLOCKED(mtx) do { } while (0)
 #endif
 
-#define MUTEX_OLDIPL(mtx)	(mtx)->mtx_oldcpl
+#define MUTEX_OLDIPL(mtx)	((mtx)->mtx_oldipl)
 
 #endif
diff --git a/sys/arch/powerpc/powerpc/lock_machdep.c b/sys/arch/powerpc/powerpc/lock_machdep.c
index 67d737d8a51..45d1df387ac 100644
--- a/sys/arch/powerpc/powerpc/lock_machdep.c
+++ b/sys/arch/powerpc/powerpc/lock_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lock_machdep.c,v 1.2 2015/06/26 12:46:13 dlg Exp $	*/
+/*	$OpenBSD: lock_machdep.c,v 1.3 2015/08/14 06:14:19 dlg Exp $	*/
 
 /*
  * Copyright (c) 2007 Artur Grabowski <art@openbsd.org>
@@ -42,8 +42,6 @@ __mp_lock_init(struct __mp_lock *lock)
 extern int __mp_lock_spinout;
 #endif
 
-#define SPINLOCK_SPIN_HOOK	/**/
-
 static __inline void
 __mp_lock_spin(struct __mp_lock *mpl)
 {
diff --git a/sys/arch/powerpc/powerpc/mutex.S b/sys/arch/powerpc/powerpc/mutex.S
deleted file mode 100644
index d597d0218c4..00000000000
--- a/sys/arch/powerpc/powerpc/mutex.S
+++ /dev/null
@@ -1,182 +0,0 @@
-/*	$OpenBSD: mutex.S,v 1.16 2014/06/18 18:42:29 kettenis Exp $	*/
-
-/*
- * Copyright (c) 2007 Dale Rahn
- * Copyright (c) 2007 Mark Kettenis
- *
- * 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 "assym.h"
-
-#include <machine/asm.h>
-
-/* XXX */
-#define GET_CPUINFO(r)	mfsprg r,0
-
-ENTRY(__mtx_init)
-	li	%r5,0
-	stw	%r4,MTX_WANTIPL(%r3)
-	stw	%r5,MTX_OLDCPL(%r3)
-	stw	%r5,MTX_OWNER(%r3)
-	blr
-
-
-ENTRY(mtx_enter)
-	stwu	%r1,-16(%r1)			# reserve stack
-	mflr	%r0
-	stw	%r0,20(%r1)			# save return address
-.L_retry:
-	stw	%r3, 12(%r1)
-	lwz	%r3,MTX_WANTIPL(%r3)		# load new ipl
-	bl	_C_LABEL(splraise)
-	mr	%r7, %r3
-	GET_CPUINFO(%r4)
-	lwz	%r3,12(%r1)
-	li	%r5,MTX_OWNER			# load offset constant
-	lwarx	%r6,%r5,%r3			# load reserve owner
-	cmpwi	0,%r6,0				# test owner == 0
-	beq+	0,.L_mutex_free			# if owner == 0 branch free
-.L_mutex_locked:
-#ifdef DIAGNOSTIC
-	cmpl	0,%r4,%r6
-	beq-	.L_mutex_selflocked
-#endif
-	stw	%r3,12(%r1)			# save mtx during lcsplx
-	la	%r4,12(%r1)
-	stwcx.	%r3,0,%r4			# unreserve owner
-	mr	%r3,%r7				# move old cpl to arg0
-	bl	_C_LABEL(lcsplx)		# call splx on old cpl
-	lwz	%r3,12(%r1)
-	b	.L_retry
-
-.L_mutex_free:
-	stwcx.	%r4,%r5,%r3			# old owner was 0 cond store
-	bne-	.L_mutex_locked			# branch if reserve cancelled
-	isync					# memory barrier
-#ifdef DIAGNOSTIC
-	lwz	%r6,CI_MUTEX_LEVEL(%r4)
-	addi	%r6,%r6,1			# curpcu->ci_mutex_level++
-	stw	%r6,CI_MUTEX_LEVEL(%r4)
-#endif
-	stw	%r7,MTX_OLDCPL(%r3)		# save old ipl
-	lwz	%r0,20(%r1)			# load return address
-	mtlr	%r0
-	addi	%r1,%r1,16			# restore stack
-	blr
-
-#ifdef DIAGNOSTIC
-.L_mutex_selflocked:
-	mr	%r5, %r3
-	lis	%r3,.L_paniclocked@ha
-	la	%r3,.L_paniclocked@l(%r3)
-	bl 	panic
-.L_paniclocked:
-	.string "mtx_enter: recursed %x %x\n"
-#endif
-
-
-ENTRY(mtx_enter_try)
-	stwu	%r1,-16(%r1)			# reserve stack
-	mflr	%r0
-	stw	%r0,20(%r1)			# save return address
-	stw	%r3, 12(%r1)
-	lwz	%r3,MTX_WANTIPL(%r3)		# load new ipl
-	bl	_C_LABEL(splraise)
-	mr	%r7, %r3
-	GET_CPUINFO(%r4)
-	lwz	%r3,12(%r1)
-	li	%r5,MTX_OWNER			# load offset constant
-	lwarx	%r6,%r5,%r3			# load reserve owner
-	cmpwi	0,%r6,0				# test owner == 0
-	beq+	0,.L_mutex_try_free		# if owner == 0 branch free
-.L_mutex_try_locked:
-#ifdef DIAGNOSTIC
-	cmpl	0,%r4,%r6
-	beq-	.L_mutex_try_selflocked
-#endif
-	stw	%r3,12(%r1)			# save mtx during lcsplx
-	la	%r4,12(%r1)
-	stwcx.	%r3,0,%r4			# unreserve owner
-	mr	%r3,%r7				# move old cpl to arg0
-	bl	_C_LABEL(lcsplx)		# call splx on old cpl
-
-	lwz	%r0,20(%r1)			# load return address
-	mtlr	%r0
-	addi	%r1,%r1,16			# restore stack
-	li	%r3,0				# return zero
-	blr
-
-.L_mutex_try_free:
-	stwcx.	%r4,%r5,%r3			# old owner was 0 cond store
-	bne-	.L_mutex_try_locked		# branch if reserve cancelled
-	isync					# memory barrier
-#ifdef DIAGNOSTIC
-	lwz	%r6,CI_MUTEX_LEVEL(%r4)
-	addi	%r6,%r6,1			# curpcu->ci_mutex_level++
-	stw	%r6,CI_MUTEX_LEVEL(%r4)
-#endif
-	stw	%r7,MTX_OLDCPL(%r3)		# save old ipl
-	lwz	%r0,20(%r1)			# load return address
-	mtlr	%r0
-	addi	%r1,%r1,16			# restore stack
-	li	%r3,1				# return nonzero
-	blr
-
-#ifdef DIAGNOSTIC
-.L_mutex_try_selflocked:
-	mr	%r5, %r3
-	lis	%r3,.L_panictrylocked@ha
-	la	%r3,.L_panictrylocked@l(%r3)
-	bl 	panic
-.L_panictrylocked:
-	.string "mtx_enter_try: recursed %x %x\n"
-#endif
-
-
-ENTRY(mtx_leave)
-#ifdef DIAGNOSTIC
-	lwz	%r6,MTX_OWNER(%r3)
-	cmpwi   0,%r6,0				# test owner == 0
-
-	beq-	.L_mutex_notlocked
-#endif
-	li	%r4,0
-	lwz	%r5,MTX_OLDCPL(%r3)
-	stw	%r4,MTX_OLDCPL(%r3)
-	sync					# memory barrier
-	stw	%r4,MTX_OWNER(%r3)
-	GET_CPUINFO(%r4)
-#ifdef DIAGNOSTIC
-	lwz	%r6,CI_MUTEX_LEVEL(%r4)
-	addi	%r6,%r6,-1			# curpcu->ci_mutex_level--
-	stw	%r6,CI_MUTEX_LEVEL(%r4)
-#endif
-	mr	%r3,%r5
-	lwz	%r5,CI_CPL(%r4)
-	cmpl	0,%r3,%r5
-	beq	1f
-	b	_C_LABEL(lcsplx)
-1:
-	blr
-
-#ifdef DIAGNOSTIC
-.L_mutex_notlocked:
-	GET_CPUINFO(%r4)
-	mr	%r5, %r3
-	lis	%r3,.L_panicnotlocked@ha
-	la	%r3,.L_panicnotlocked@l(%r3)
-	bl 	panic
-.L_panicnotlocked:
-	.string "mtx_leave: not locked %x %x\n"
-#endif
diff --git a/sys/arch/powerpc/powerpc/mutex.c b/sys/arch/powerpc/powerpc/mutex.c
new file mode 100644
index 00000000000..dd89ae0747f
--- /dev/null
+++ b/sys/arch/powerpc/powerpc/mutex.c
@@ -0,0 +1,150 @@
+/*	$OpenBSD: mutex.c,v 1.1 2015/08/14 06:14:19 dlg Exp $	*/
+
+/*
+ * Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED ``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. 
+ */
+
+#include <sys/param.h>
+#include <sys/mutex.h>
+#include <sys/systm.h>
+#include <sys/atomic.h>
+
+#include <machine/intr.h>
+#include <machine/lock.h>
+
+#include <ddb/db_output.h>
+
+void
+__mtx_init(struct mutex *mtx, int ipl)
+{
+	mtx->mtx_owner = NULL;
+	mtx->mtx_wantipl = ipl;
+	mtx->mtx_oldipl = IPL_NONE;
+}
+
+#ifdef MULTIPROCESSOR
+#if defined(MP_LOCKDEBUG)
+#ifndef DDB
+#error "MP_LOCKDEBUG requires DDB"
+#endif
+
+/* CPU-dependent timing, needs this to be settable from ddb. */
+extern int __mp_lock_spinout;
+#endif
+
+void
+mtx_enter(struct mutex *mtx)
+{
+#if defined(MP_LOCKDEBUG)
+	int ticks = __mp_lock_spinout;
+#endif
+
+	while (mtx_enter_try(mtx) == 0) {
+		SPINLOCK_SPIN_HOOK;
+
+#if defined(MP_LOCKDEBUG)
+		if (--ticks == 0) {
+			db_printf("%s: %p lock spun out", __func__, mtx);
+			Debugger();
+		}
+#endif
+	}
+}
+
+int
+mtx_enter_try(struct mutex *mtx)
+{
+	struct cpu_info *owner, *ci = curcpu();
+	int s;
+
+	if (mtx->mtx_wantipl != IPL_NONE)
+		s = splraise(mtx->mtx_wantipl);
+
+	owner = atomic_cas_ptr(&mtx->mtx_owner, NULL, ci);
+#ifdef DIAGNOSTIC
+	if (__predict_false(owner == ci))
+		panic("mtx %p: locking against myself", mtx);
+#endif
+	if (owner == NULL) {
+		if (mtx->mtx_wantipl != IPL_NONE)
+			mtx->mtx_oldipl = s;
+#ifdef DIAGNOSTIC
+		ci->ci_mutex_level++;
+#endif
+		membar_enter();
+		return (1);
+	}
+
+	if (mtx->mtx_wantipl != IPL_NONE)
+		splx(s);
+
+	return (0);
+}
+#else
+void
+mtx_enter(struct mutex *mtx)
+{
+	struct cpu_info *ci = curcpu();
+
+#ifdef DIAGNOSTIC
+	if (__predict_false(mtx->mtx_owner == ci))
+		panic("mtx %p: locking against myself", mtx);
+#endif
+	if (mtx->mtx_wantipl != IPL_NONE)
+		mtx->mtx_oldipl = splraise(mtx->mtx_wantipl);
+
+	mtx->mtx_owner = ci;
+
+#ifdef DIAGNOSTIC
+	ci->ci_mutex_level++;
+#endif
+}
+
+int
+mtx_enter_try(struct mutex *mtx)
+{
+	mtx_enter(mtx);
+	return (1);
+}
+#endif
+
+void
+mtx_leave(struct mutex *mtx)
+{
+	int s;
+
+	MUTEX_ASSERT_LOCKED(mtx);
+
+#ifdef MULTIPROCESSOR
+	membar_exit();
+#endif
+#ifdef DIAGNOSTIC
+	curcpu()->ci_mutex_level--;
+#endif
+
+	s = mtx->mtx_oldipl;
+	mtx->mtx_owner = NULL;
+	if (mtx->mtx_wantipl != IPL_NONE)
+		splx(s);
+}