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authorRichard Weinberger <richard@nod.at>2011-07-25 17:12:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-25 20:57:12 -0700
commit22e9b917ab7ccd98046ad9428fb28967f0744605 (patch)
treefb21871390d662b0c9cccd05ee3180336afe8e4f /arch/um/sys-i386
parentc0ce5b673457123406f19e616bb8cf20a0c12cb5 (diff)
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>
Diffstat (limited to 'arch/um/sys-i386')
-rw-r--r--arch/um/sys-i386/delay.c59
1 files changed, 45 insertions, 14 deletions
diff --git a/arch/um/sys-i386/delay.c b/arch/um/sys-i386/delay.c
index d623e074f41d..f3fe1a688f7e 100644
--- 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);

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