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x86: simplify set_bitmap in ioport_32.c 

Simplify set_bitmap(). This is not in a hotpath and we really can use the
straight forward loop through those bits. A similar implementation is used
in the 64 bit code as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner 2008-01-30 13:30:23 +01:00 committed by Ingo Molnar
parent 3ebc51d7c9
commit f2f58178f4
1 changed files with 6 additions and 26 deletions
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32
arch/x86/kernel/ioport_32.c
View File

@ -16,36 +16,16 @@
#include <linux/syscalls.h>
/* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
static void set_bitmap(unsigned long *bitmap, unsigned int base, unsigned int extent, int new_value)
static void set_bitmap(unsigned long *bitmap, unsigned int base,
unsigned int extent, int new_value)
{
unsigned long mask;
unsigned long *bitmap_base = bitmap + (base / BITS_PER_LONG);
unsigned int low_index = base & (BITS_PER_LONG-1);
int length = low_index + extent;
unsigned int i;
if (low_index != 0) {
mask = (~0UL << low_index);
if (length < BITS_PER_LONG)
mask &= ~(~0UL << length);
for (i = base; i < base + extent; i++) {
if (new_value)
*bitmap_base++ |= mask;
__set_bit(i, bitmap);
else
*bitmap_base++ &= ~mask;
length -= BITS_PER_LONG;
}
mask = (new_value ? ~0UL : 0UL);
while (length >= BITS_PER_LONG) {
*bitmap_base++ = mask;
length -= BITS_PER_LONG;
}
if (length > 0) {
mask = ~(~0UL << length);
if (new_value)
*bitmap_base++ |= mask;
else
*bitmap_base++ &= ~mask;
__clear_bit(i, bitmap);
}
}