Real mutexes for sparc64. Some comments from henric@ and claudio@.

Tested by fkr@, claudio@, nick@.

4 files changed, 82 insertions, 82 deletions

diff --git a/sys/arch/sparc64/conf/files.sparc64 b/sys/arch/sparc64/conf/files.sparc64
index ce8966276ec..b4a2764d28b 100644
--- a/sys/arch/sparc64/conf/files.sparc64
+++ b/sys/arch/sparc64/conf/files.sparc64
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.sparc64,v 1.87 2007/08/21 21:45:29 kettenis Exp $
+#	$OpenBSD: files.sparc64,v 1.88 2007/08/25 18:36:47 kettenis Exp $
 #	$NetBSD: files.sparc64,v 1.50 2001/08/10 20:53:50 eeh Exp $
 
 # maxpartitions must be first item in files.${ARCH}
@@ -245,7 +245,7 @@ file	arch/sparc64/sparc64/kgdb_machdep.c	kgdb
 file	arch/sparc64/sparc64/locore2.c
 file	arch/sparc64/sparc64/machdep.c
 file	arch/sparc64/sparc64/mem.c
-file	arch/sparc64/sparc64/mutex.c
+file	arch/sparc64/sparc64/mutex.S
 file	arch/sparc64/sparc64/openprom.c
 file	arch/sparc64/sparc64/openfirm.c
 file	arch/sparc64/sparc64/ofw_machdep.c
diff --git a/sys/arch/sparc64/include/mutex.h b/sys/arch/sparc64/include/mutex.h
index 158c43c56bd..8b8654ee554 100644
--- a/sys/arch/sparc64/include/mutex.h
+++ b/sys/arch/sparc64/include/mutex.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mutex.h,v 1.1 2007/02/03 20:08:50 miod Exp $	*/
+/*	$OpenBSD: mutex.h,v 1.2 2007/08/25 18:36:47 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
@@ -28,27 +28,22 @@
 #ifndef _MACHINE_MUTEX_H_
 #define _MACHINE_MUTEX_H_
 
-/*
- * Simple non-mp implementation.
- */
 struct mutex {
-	int mtx_lock;
+	__volatile void *mtx_owner; /* mutex.S relies upon this being first */
 	int mtx_wantipl;
 	int mtx_oldipl;
 };
 
-void mtx_init(struct mutex *, int);
-
-#define MUTEX_INITIALIZER(ipl) { 0, ipl, 0 }
+#define MUTEX_INITIALIZER(ipl) { NULL, ipl, 0 }
 
 #ifdef DIAGNOSTIC
 #define MUTEX_ASSERT_LOCKED(mtx) do {					\
-	if ((mtx)->mtx_lock == 0)					\
+	if ((mtx)->mtx_owner != curcpu())				\
 		panic("mutex %p not held in %s", (mtx), __func__);	\
 } while (0)
 
 #define MUTEX_ASSERT_UNLOCKED(mtx) do {					\
-	if ((mtx)->mtx_lock != 0)					\
+	if ((mtx)->mtx_owner == curcpu())				\
 		panic("mutex %p held in %s", (mtx), __func__);		\
 } while (0)
 #else
diff --git a/sys/arch/sparc64/sparc64/mutex.S b/sys/arch/sparc64/sparc64/mutex.S
new file mode 100644
index 00000000000..70f7e146041
--- /dev/null
+++ b/sys/arch/sparc64/sparc64/mutex.S
@@ -0,0 +1,75 @@
+/*	$OpenBSD: mutex.S,v 1.1 2007/08/25 18:36:47 kettenis Exp $	*/
+
+/*
+ * 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.
+ */
+
+/*
+ * Mutex implementation based on Example 9 from Appendix J of
+ * SPARC-V9/R1.4.5, The SPARC Architecture Manual.
+ */
+
+#include "assym.h"
+#include <machine/asm.h>
+#include <machine/param.h>
+
+ENTRY(mtx_init)
+	stx	%g0, [%o0 + MTX_OWNER]
+	stw	%o1, [%o0 + MTX_WANTIPL]
+	retl
+	 stw	%g0, [%o0 + MTX_OLDIPL]
+
+ENTRY(mtx_enter)
+#ifdef MULTIPROCESSOR
+	sethi	%hi(CPUINFO_VA+CI_SELF), %g1
+	ldx	[%g1 + %lo(CPUINFO_VA+CI_SELF)], %g1
+#else
+	set	CPUINFO_VA, %g1
+#endif
+	rdpr	%pil, %g4
+1:
+	ld	[%o0 + MTX_WANTIPL], %g5
+	cmp	%g4, %g5
+	bge	2f
+	 nop
+	wrpr	%g5, %pil
+2:
+	mov	%g1, %g5
+/*
+ * The assembler doesn't like the next line, even if MTX_OWNER is 0.
+ */
+!	casx	[%o0 + MTX_OWNER], %g0, %g5
+	casx	[%o0], %g0, %g5
+	tst	%g5
+	be	4f
+	 nop
+	wrpr	%g4, %pil
+3:
+	ldx	[%o0 + MTX_OWNER], %g5
+	tst	%g5
+	bne	3b
+	 nop
+	ba,a	1b
+4:
+	stw	%g4, [%o0 + MTX_OLDIPL]
+	retl
+	 membar	#LoadLoad | #LoadStore
+
+ENTRY(mtx_leave)
+	ld	[%o0 + MTX_OLDIPL], %g1
+	membar	#StoreStore | #LoadStore
+	stx	%g0, [%o0 + MTX_OWNER]
+	retl
+	 wrpr	%g1, %pil
diff --git a/sys/arch/sparc64/sparc64/mutex.c b/sys/arch/sparc64/sparc64/mutex.c
deleted file mode 100644
index 79ce415f06b..00000000000
--- a/sys/arch/sparc64/sparc64/mutex.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/*	$OpenBSD: mutex.c,v 1.1 2007/02/03 20:08:50 miod 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 <machine/psl.h>
-#include <machine/intr.h>
-
-#ifdef MULTIPROCESSOR
-#error This code needs more work
-#endif
-
-/*
- * Single processor systems don't need any mutexes, but they need the spl
- * raising semantics of the mutexes.
- */
-void
-mtx_init(struct mutex *mtx, int wantipl)
-{
-	mtx->mtx_oldipl = 0;
-	mtx->mtx_wantipl = wantipl;
-	mtx->mtx_lock = 0;
-}
-
-void
-mtx_enter(struct mutex *mtx)
-{
-	if (mtx->mtx_wantipl != IPL_NONE) {
-		mtx->mtx_oldipl = sparc_rdpr(pil);
-		if (mtx->mtx_oldipl < mtx->mtx_wantipl)
-			sparc_wrpr(pil, mtx->mtx_wantipl, 0);
-	}
-
-	MUTEX_ASSERT_UNLOCKED(mtx);
-	mtx->mtx_lock = 1;
-}
-
-void
-mtx_leave(struct mutex *mtx)
-{
-	MUTEX_ASSERT_LOCKED(mtx);
-	mtx->mtx_lock = 0;
-	if (mtx->mtx_wantipl != IPL_NONE)
-		splx(mtx->mtx_oldipl);
-}