patch-2.3.48 linux/include/asm-mips64/delay.h

• Lines: 55
• Date: Thu Feb 24 22:53:35 2000
• Orig file: v2.3.47/linux/include/asm-mips64/delay.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.47/linux/include/asm-mips64/delay.h linux/include/asm-mips64/delay.h
@@ -0,0 +1,54 @@
+/* $Id: delay.h,v 1.1 1999/08/18 23:37:50 ralf Exp $
+ *
+ * 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) 1994 by Waldorf Electronics
+ * Copyright (C) 1995 - 1999 by Ralf Baechle
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_DELAY_H
+#define _ASM_DELAY_H
+
+extern __inline__ void
+__delay(unsigned long loops)
+{
+	__asm__ __volatile__ (
+		".set\tnoreorder\n"
+		"1:\tbnez\t%0,1b\n\t"
+		"dsubu\t%0,1\n\t"
+		".set\treorder"
+		:"=r" (loops)
+		:"0" (loops));
+}
+
+/*
+ * Division by multiplication: you don't have to worry about
+ * loss of precision.
+ *
+ * Use only for very small delays ( < 1 msec).  Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays.  This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+extern __inline__ void __udelay(unsigned long usecs, unsigned long lps)
+{
+	usecs *= 0x000010c6f7a0b5edUL;		/* 2**64 / 1000000 */
+	__asm__("dmultu\t%0,%2\n\t"
+		"mfhi\t%0"
+		:"=r" (usecs)
+		:"0" (usecs),"r" (lps));
+	__delay(usecs);
+}
+
+#ifdef __SMP__
+#define __udelay_val cpu_data[smp_processor_id()].udelay_val
+#else
+#define __udelay_val loops_per_sec
+#endif
+
+#define udelay(usecs) __udelay((usecs),__udelay_val)
+
+#endif /* _ASM_DELAY_H */