1 files changed, 93 insertions, 0 deletions
diff --git a/include/asm-mips/delay.h b/include/asm-mips/delay.h
new file mode 100644
index 000000000000..d0f68447e5a7
--- /dev/null
+++ b/include/asm-mips/delay.h
@@ -0,0 +1,93 @@
+/*
+ * 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 - 2000, 01, 03 by Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_DELAY_H
+#define _ASM_DELAY_H
+
+#include <linux/config.h>
+#include <linux/param.h>
+
+#include <asm/compiler.h>
+
+extern unsigned long loops_per_jiffy;
+
+static inline void __delay(unsigned long loops)
+{
+	if (sizeof(long) == 4)
+		__asm__ __volatile__ (
+		".set\tnoreorder\n"
+		"1:\tbnez\t%0,1b\n\t"
+		"subu\t%0,1\n\t"
+		".set\treorder"
+		: "=r" (loops)
+		: "0" (loops));
+	else if (sizeof(long) == 8)
+		__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)
+ */
+
+static inline void __udelay(unsigned long usecs, unsigned long lpj)
+{
+	unsigned long lo;
+
+	/*
+	 * The common rates of 1000 and 128 are rounded wrongly by the
+	 * catchall case for 64-bit.  Excessive precission?  Probably ...
+	 */
+#if defined(CONFIG_MIPS64) && (HZ == 128)
+	usecs *= 0x0008637bd05af6c7UL;		/* 2**64 / (1000000 / HZ) */
+#elif defined(CONFIG_MIPS64) && (HZ == 1000)
+	usecs *= 0x004189374BC6A7f0UL;		/* 2**64 / (1000000 / HZ) */
+#elif defined(CONFIG_MIPS64)
+	usecs *= (0x8000000000000000UL / (500000 / HZ));
+#else /* 32-bit junk follows here */
+	usecs *= (unsigned long) (((0x8000000000000000ULL / (500000 / HZ)) +
+	                           0x80000000ULL) >> 32);
+#endif
+
+	if (sizeof(long) == 4)
+		__asm__("multu\t%2, %3"
+		: "=h" (usecs), "=l" (lo)
+		: "r" (usecs), "r" (lpj)
+		: GCC_REG_ACCUM);
+	else if (sizeof(long) == 8)
+		__asm__("dmultu\t%2, %3"
+		: "=h" (usecs), "=l" (lo)
+		: "r" (usecs), "r" (lpj)
+		: GCC_REG_ACCUM);
+
+	__delay(usecs);
+}
+
+#ifdef CONFIG_SMP
+#define __udelay_val cpu_data[smp_processor_id()].udelay_val
+#else
+#define __udelay_val loops_per_jiffy
+#endif
+
+#define udelay(usecs) __udelay((usecs),__udelay_val)
+
+#endif /* _ASM_DELAY_H */