mirror of
https://github.com/torvalds/linux
synced 2024-09-06 09:51:23 +00:00
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: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
parent
552eb975b8
commit
64af4e0da4
|
@ -1,10 +1,17 @@
|
|||
/* 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
|
||||
|
@ -12,10 +19,41 @@
|
|||
*/
|
||||
|
||||
#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)
|
||||
|
||||
/*
|
||||
* 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.
|
||||
*/
|
||||
static unsigned long _find_next_bit(const unsigned long *addr,
|
||||
unsigned long nbits, unsigned long start, unsigned long invert)
|
||||
{
|
||||
unsigned long tmp;
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
return min(start + __ffs(tmp), nbits);
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifndef find_next_bit
|
||||
/*
|
||||
|
@ -24,40 +62,7 @@
|
|||
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
|
||||
unsigned long offset)
|
||||
{
|
||||
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;
|
||||
}
|
||||
while (size & ~(BITS_PER_LONG-1)) {
|
||||
if ((tmp = *(p++)))
|
||||
goto found_middle;
|
||||
result += BITS_PER_LONG;
|
||||
size -= BITS_PER_LONG;
|
||||
}
|
||||
if (!size)
|
||||
return result;
|
||||
tmp = *p;
|
||||
|
||||
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);
|
||||
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
|
||||
|
|
|
@ -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) ? \
|
||||
|
|
Loading…
Reference in a new issue