patch-2.4.22 linux-2.4.22/include/asm-mips64/semaphore.h

• Lines: 92
• Date: 2003-08-25 04:44:44.000000000 -0700
• Orig file: linux-2.4.21/include/asm-mips64/semaphore.h
• Orig date: 2002-11-28 15:53:15.000000000 -0800

diff -urN linux-2.4.21/include/asm-mips64/semaphore.h linux-2.4.22/include/asm-mips64/semaphore.h
@@ -1,14 +1,17 @@
 /*
+ * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
  * Copyright (C) 1996  Linus Torvalds
- * Copyright (C) 1998, 1999, 2000, 2001  Ralf Baechle
- * Copyright (C) 1999, 2000, 2001  Silicon Graphics, Inc.
+ * Copyright (C) 1998, 99, 2000, 01  Ralf Baechle
+ * Copyright (C) 1999, 2000, 01  Silicon Graphics, Inc.
+ * Copyright (C) 2000, 01 MIPS Technologies, Inc.
  */
 #ifndef _ASM_SEMAPHORE_H
 #define _ASM_SEMAPHORE_H
 
+#include <linux/config.h>
 #include <asm/system.h>
 #include <asm/atomic.h>
 #include <linux/spinlock.h>
@@ -27,7 +30,7 @@
 #if WAITQUEUE_DEBUG
 	long __magic;
 #endif
-};
+} __attribute__((aligned(8)));
 
 #if WAITQUEUE_DEBUG
 # define __SEM_DEBUG_INIT(name) \
@@ -105,6 +108,22 @@
 	return ret;
 }
 
+#ifndef CONFIG_CPU_HAS_LLDSCD
+
+/*
+ * Non-blockingly attempt to down() a semaphore.
+ * Returns zero if we acquired it
+ */
+static inline int down_trylock(struct semaphore * sem)
+{
+	int ret = 0;
+	if (atomic_dec_return(&sem->count) < 0)
+		ret = __down_trylock(sem);
+	return ret;
+}
+
+#else
+
 /*
  * down_trylock returns 0 on success, 1 if we failed to get the lock.
  *
@@ -137,19 +156,19 @@
 	__asm__ __volatile__(
 	".set\tmips3\t\t\t# down_trylock\n"
 	"0:\tlld\t%1, %4\n\t"
-	"\tdli\t%3, 0x0000000100000000\n\t"
-	"\tdsubu\t%1, %3\n\t"
-	"\tli\t%0, 0\n\t"
-	"\tbgez\t%1, 2f\n\t"
-	"\tsll\t%2, %1, 0\n\t"
-	"\tblez\t%2, 1f\n\t"
-	"\tdaddiu\t%1, %1, -1\n\t"
-	"\tb\t2f\n"
+	"dli\t%3, 0x0000000100000000\n\t"
+	"dsubu\t%1, %3\n\t"
+	"li\t%0, 0\n\t"
+	"bgez\t%1, 2f\n\t"
+	"sll\t%2, %1, 0\n\t"
+	"blez\t%2, 1f\n\t"
+	"daddiu\t%1, %1, -1\n\t"
+	"b\t2f\n"
 	"1:\tdaddu\t%1, %1, %3\n\t"
-	"\tli\t%0, 1\n"
+	"li\t%0, 1\n"
 	"2:\tscd\t%1, %4\n\t"
-	"\tbeqz\t%1, 0b\n\t"
-	"\t.set\tmips0"
+	"beqz\t%1, 0b\n\t"
+	".set\tmips0"
 	: "=&r"(ret), "=&r"(tmp), "=&r"(tmp2), "=&r"(sub)
 	: "m"(*sem)
 	: "memory");
@@ -157,6 +176,8 @@
 	return ret;
 }
 
+#endif /* CONFIG_CPU_HAS_LLDSCD */
+
 /*
  * Note! This is subtle. We jump to wake people up only if
  * the semaphore was negative (== somebody was waiting on it).