um: clean up delay functions
Both sys-i386 and sys-x86_64 support now ndelay(). The delay functions
are based on arch/x86/lib/delay.c.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/sys-x86_64/delay.c b/arch/um/sys-x86_64/delay.c
index dee5be6..f3fe1a6 100644
--- a/arch/um/sys-x86_64/delay.c
+++ b/arch/um/sys-x86_64/delay.c
@@ -1,30 +1,60 @@
/*
- * Copyright 2003 PathScale, Inc.
- * Copied from arch/x86_64
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ * Mostly copied from arch/x86/lib/delay.c
*
- * Licensed under the GPL
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
*/
#include <linux/module.h>
+#include <linux/kernel.h>
#include <linux/delay.h>
-#include <asm/processor.h>
#include <asm/param.h>
void __delay(unsigned long loops)
{
- unsigned long i;
+ asm volatile(
+ "test %0,%0\n"
+ "jz 3f\n"
+ "jmp 1f\n"
- for(i = 0; i < loops; i++)
- cpu_relax();
+ ".align 16\n"
+ "1: jmp 2f\n"
+
+ ".align 16\n"
+ "2: dec %0\n"
+ " jnz 2b\n"
+ "3: dec %0\n"
+
+ : /* we don't need output */
+ : "a" (loops)
+ );
}
+EXPORT_SYMBOL(__delay);
+
+inline void __const_udelay(unsigned long xloops)
+{
+ int d0;
+
+ xloops *= 4;
+ asm("mull %%edx"
+ : "=d" (xloops), "=&a" (d0)
+ : "1" (xloops), "0"
+ (loops_per_jiffy * (HZ/4)));
+
+ __delay(++xloops);
+}
+EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
- unsigned long i, n;
-
- n = (loops_per_jiffy * HZ * usecs) / MILLION;
- for(i=0;i<n;i++)
- cpu_relax();
+ __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
}
-
EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+ __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);