Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 64af4e0d authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

tools lib: Sync tools/lib/find_bit.c with the kernel 

Need to move the bitmap.[ch] things from tools/perf/ to tools/lib, will
be done in the next patches.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: George Spelvin <linux@horizon.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yury Norov <yury.norov@gmail.com>
Link: http://lkml.kernel.org/n/tip-5fys65wkd7gu8j7a7xgukc5t@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 552eb975

tools/lib/find_bit.c

+49 −54
Original line number Diff line number Diff line 
/* find_next_bit.c: fallback find next bit implementation

/* bit search implementation

 *

 * Copied from lib/find_next_bit.c to tools/lib/find_bit.c

 * Copied from lib/find_bit.c to tools/lib/find_bit.c

 *

 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.

 * Written by David Howells (dhowells@redhat.com)

 *

 * Copyright (C) 2008 IBM Corporation

 * 'find_last_bit' is written by Rusty Russell <rusty@rustcorp.com.au>

 * (Inspired by David Howell's find_next_bit implementation)

 *

 * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease

 * size and improve performance, 2015.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version
@@ -12,52 +19,50 @@ 
 */



#include <linux/bitops.h>

#include <asm/types.h>

#include <asm/byteorder.h>

#include <linux/bitmap.h>

#include <linux/kernel.h>



#define BITOP_WORD(nr)		((nr) / BITS_PER_LONG)

#if !defined(find_next_bit)



#ifndef find_next_bit

/*

 * Find the next set bit in a memory region.

 * This is a common helper function for find_next_bit and

 * find_next_zero_bit.  The difference is the "invert" argument, which

 * is XORed with each fetched word before searching it for one bits.

 */

unsigned long find_next_bit(const unsigned long *addr, unsigned long size,

			    unsigned long offset)

static unsigned long _find_next_bit(const unsigned long *addr,

		unsigned long nbits, unsigned long start, unsigned long invert)

{

	const unsigned long *p = addr + BITOP_WORD(offset);

	unsigned long result = offset & ~(BITS_PER_LONG-1);

	unsigned long tmp;



	if (offset >= size)

		return size;

	size -= result;

	offset %= BITS_PER_LONG;

	if (offset) {

		tmp = *(p++);

		tmp &= (~0UL << offset);

		if (size < BITS_PER_LONG)

			goto found_first;

		if (tmp)

			goto found_middle;

		size -= BITS_PER_LONG;

		result += BITS_PER_LONG;

	if (!nbits || start >= nbits)

		return nbits;



	tmp = addr[start / BITS_PER_LONG] ^ invert;



	/* Handle 1st word. */

	tmp &= BITMAP_FIRST_WORD_MASK(start);

	start = round_down(start, BITS_PER_LONG);



	while (!tmp) {

		start += BITS_PER_LONG;

		if (start >= nbits)

			return nbits;



		tmp = addr[start / BITS_PER_LONG] ^ invert;

	}

	while (size & ~(BITS_PER_LONG-1)) {

		if ((tmp = *(p++)))

			goto found_middle;

		result += BITS_PER_LONG;

		size -= BITS_PER_LONG;



	return min(start + __ffs(tmp), nbits);

}

	if (!size)

		return result;

	tmp = *p;

#endif



found_first:

	tmp &= (~0UL >> (BITS_PER_LONG - size));

	if (tmp == 0UL)		/* Are any bits set? */

		return result + size;	/* Nope. */

found_middle:

	return result + __ffs(tmp);

#ifndef find_next_bit

/*

 * Find the next set bit in a memory region.

 */

unsigned long find_next_bit(const unsigned long *addr, unsigned long size,

			    unsigned long offset)

{

	return _find_next_bit(addr, size, offset, 0UL);

}

#endif
@@ -67,23 +72,13 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size, 
 */

unsigned long find_first_bit(const unsigned long *addr, unsigned long size)

{

	const unsigned long *p = addr;

	unsigned long result = 0;

	unsigned long tmp;

	unsigned long idx;



	while (size & ~(BITS_PER_LONG-1)) {

		if ((tmp = *(p++)))

			goto found;

		result += BITS_PER_LONG;

		size -= BITS_PER_LONG;

	for (idx = 0; idx * BITS_PER_LONG < size; idx++) {

		if (addr[idx])

			return min(idx * BITS_PER_LONG + __ffs(addr[idx]), size);

	}

	if (!size)

		return result;



	tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));

	if (tmp == 0UL)		/* Are any bits set? */

		return result + size;	/* Nope. */

found:

	return result + __ffs(tmp);

	return size;

}

#endif

tools/perf/util/include/linux/bitmap.h

+2 −0
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ int __bitmap_weight(const unsigned long *bitmap, int bits); 
void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,

		 const unsigned long *bitmap2, int bits);



#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))



#define BITMAP_LAST_WORD_MASK(nbits)					\

(									\

	((nbits) % BITS_PER_LONG) ?					\