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Commit f2f58178 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
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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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 3ebc51d7

arch/x86/kernel/ioport_32.c

+6 −26
Original line number Diff line number Diff line
@@ -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;



	if (low_index != 0) {

		mask = (~0UL << low_index);

		if (length < BITS_PER_LONG)

			mask &= ~(~0UL << length);

		if (new_value)

			*bitmap_base++ |= mask;

		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;

	}

	unsigned int i;



	if (length > 0) {

		mask = ~(~0UL << length);

	for (i = base; i < base + extent; i++) {

		if (new_value)

			*bitmap_base++ |= mask;

			__set_bit(i, bitmap);

		else

			*bitmap_base++ &= ~mask;

			__clear_bit(i, bitmap);

	}

}