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  • Committer: Package Import Robot
  • Author(s): Alessio Igor Bogani
  • Date: 2011-10-26 11:13:05 UTC
  • Revision ID: package-import@ubuntu.com-20111026111305-tz023xykf0i6eosh
Tags: upstream-3.2.0
Import upstream version 3.2.0

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lib/find_last_bit.c
 
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/* find_last_bit.c: fallback find next bit implementation
 
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 *
 
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 * Copyright (C) 2008 IBM Corporation
 
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 * Written by Rusty Russell <rusty@rustcorp.com.au>
 
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 * (Inspired by David Howell's find_next_bit implementation)
 
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 *
 
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 * This program is free software; you can redistribute it and/or
 
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 * modify it under the terms of the GNU General Public License
 
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 * as published by the Free Software Foundation; either version
 
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 * 2 of the License, or (at your option) any later version.
 
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 */
 
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#include <linux/bitops.h>
 
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#include <linux/module.h>
 
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#include <asm/types.h>
 
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#include <asm/byteorder.h>
 
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#ifndef find_last_bit
 
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unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
 
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{
 
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        unsigned long words;
 
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        unsigned long tmp;
 
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        /* Start at final word. */
 
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        words = size / BITS_PER_LONG;
 
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        /* Partial final word? */
 
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        if (size & (BITS_PER_LONG-1)) {
 
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                tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
 
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                                         - (size & (BITS_PER_LONG-1)))));
 
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                if (tmp)
 
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                        goto found;
 
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        }
 
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        while (words) {
 
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                tmp = addr[--words];
 
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                if (tmp) {
 
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found:
 
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                        return words * BITS_PER_LONG + __fls(tmp);
 
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                }
 
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        }
 
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        /* Not found */
 
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        return size;
 
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}
 
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EXPORT_SYMBOL(find_last_bit);
 
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#endif