um: clean up delay functions

[pandora-kernel.git] / arch / um / sys-i386 / delay.c

diff --git a/arch/um/sys-i386/delay.c b/arch/um/sys-i386/delay.c
index d623e07..f3fe1a6 100644 (file)
--- a/arch/um/sys-i386/delay.c
+++ b/arch/um/sys-i386/delay.c
@@ -1,29 +1,60 @@
+/*
+ * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
+ * Mostly copied from arch/x86/lib/delay.c
+ *
+ * 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/param.h>
 
-void __delay(unsigned long time)
+void __delay(unsigned long loops)
 {
-       /* Stolen from the i386 __loop_delay */
-       int d0;
-       __asm__ __volatile__(
-               "\tjmp 1f\n"
+       asm volatile(
+               "test %0,%0\n"
+               "jz 3f\n"
+               "jmp 1f\n"
+
                ".align 16\n"
-               "1:\tjmp 2f\n"
+               "1: jmp 2f\n"
+
                ".align 16\n"
-               "2:\tdecl %0\n\tjns 2b"
-               :"=&a" (d0)
-               :"0" (time));
+               "2: dec %0\n"
+               " jnz 2b\n"
+               "3: dec %0\n"
+
+               : /* we don't need output */
+               : "a" (loops)
+       );
 }
+EXPORT_SYMBOL(__delay);
 
-void __udelay(unsigned long usecs)
+inline void __const_udelay(unsigned long xloops)
 {
-       int i, n;
+       int d0;
 
-       n = (loops_per_jiffy * HZ * usecs) / MILLION;
-        for(i=0;i<n;i++)
-                cpu_relax();
+       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)
+{
+       __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);