Move atomic_lock code from asm to C with inline asm;

Add m68k, mips and sparc. (needs more careful checking)
Add 'slow_atomic_lock' for crippled archs.

2 files changed, 33 insertions, 58 deletions

diff --git a/lib/libpthread/arch/alpha/_atomic_lock.S b/lib/libpthread/arch/alpha/_atomic_lock.S
deleted file mode 100644
index ba0022e4a4d..00000000000
--- a/lib/libpthread/arch/alpha/_atomic_lock.S
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>.
- * All rights reserved.
- * copyright Douglas Santry 1996
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the above copyright is retained
- * in the source form.
- *
- * THIS SOFTWARE IS PROVIDED BY Douglas Santry AND CONTRIBUTORS ``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 Douglas Santry OR CONTRIBUTORS 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.    
- *
- * $Id: _atomic_lock.S,v 1.1 1998/08/28 01:54:57 d Exp $
- * $OpenBSD: _atomic_lock.S,v 1.1 1998/08/28 01:54:57 d Exp $
- *
- */
-
-#include "SYS.h"
-
-/*
- * Atomicly lock a location with an identifier provided the location
- * is not currently locked.
- *
- * long _atomic_lock(long *);
- * v0 will contain the return value (zero if lock obtained).
- */
-LEAF(_atomic_lock,0)
-	LDGP(pv)
-
-	/* Get the existing lock value and lock memory: */
-	ldq_l	v0, 0(a0)
-
-	/* Branch if already locked: */
-	bne	v0, already_locked
-
-	/* Not locked, so store 1: */
-	mov	1, t0
-	stq_c	t0, 0(a0)
-
-	/* Obtained the lock: */
-	br	done
-
-already_locked:
-	/* Already locked so put the value back and unlock memory: */
-	stq_c	v0, 0(a0)
-	
-done:
-	RET
-END(_atomic_lock)
diff --git a/lib/libpthread/arch/alpha/_atomic_lock.c b/lib/libpthread/arch/alpha/_atomic_lock.c
new file mode 100644
index 00000000000..74575fc11d7
--- /dev/null
+++ b/lib/libpthread/arch/alpha/_atomic_lock.c
@@ -0,0 +1,33 @@
+/*	$OpenBSD: _atomic_lock.c,v 1.1 1998/11/20 11:15:35 d Exp $	*/
+/* Atomic lock for alpha */
+
+#include "spinlock.h"
+
+register_t
+_atomic_lock(volatile register_t * lock)
+{
+	register_t old;
+	register_t new;
+	int success;
+
+	do {
+		/* load the value of the thread-lock (lock mem on load) */
+		__asm__( "ldq_l %0, %1" : "=r"(old) : "m"(*lock) );
+		if (old) 
+			new = old;	/* in-use: put it back */
+		else
+			new = 1;	/* free: store a 1 in the lock */
+
+		success = 0;
+		/* store the new value of the thrd-lock (unlock mem on store) */
+		/*
+		 * XXX may need to add large branch forward for main line
+		 * branch prediction to be right :(
+		 */
+		__asm__( "stq_c %2, %0; beq %2, 1f; mov 1,%1; 1:"
+					: "=m"(*lock), "=r"(success)
+					: "r"(new) );
+	} while (!success);
+
+	return old;
+}