7c3892fc82
missing includes which are needed when the header files are not included in a particular order. MFC after: 1 month Sponsored by: Mellanox Technologies
519 lines
13 KiB
C
519 lines
13 KiB
C
/*-
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* Copyright (c) 2010 Isilon Systems, Inc.
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* Copyright (c) 2010 iX Systems, Inc.
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* Copyright (c) 2010 Panasas, Inc.
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* Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _LINUX_BITOPS_H_
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#define _LINUX_BITOPS_H_
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#ifdef __LP64__
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#define BITS_PER_LONG 64
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#else
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#define BITS_PER_LONG 32
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#endif
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#define BIT_MASK(n) (~0UL >> (BITS_PER_LONG - (n)))
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#define BITS_TO_LONGS(n) howmany((n), BITS_PER_LONG)
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#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
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#define BITS_PER_BYTE 8
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static inline int
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__ffs(int mask)
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{
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return (ffs(mask) - 1);
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}
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static inline int
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__fls(int mask)
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{
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return (fls(mask) - 1);
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}
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static inline int
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__ffsl(long mask)
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{
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return (ffsl(mask) - 1);
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}
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static inline int
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__flsl(long mask)
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{
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return (flsl(mask) - 1);
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}
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#define ffz(mask) __ffs(~(mask))
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static inline int get_count_order(unsigned int count)
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{
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int order;
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order = fls(count) - 1;
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if (count & (count - 1))
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order++;
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return order;
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}
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static inline unsigned long
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find_first_bit(unsigned long *addr, unsigned long size)
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{
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long mask;
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int bit;
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for (bit = 0; size >= BITS_PER_LONG;
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size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
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if (*addr == 0)
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continue;
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return (bit + __ffsl(*addr));
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}
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if (size) {
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mask = (*addr) & BIT_MASK(size);
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if (mask)
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bit += __ffsl(mask);
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else
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bit += size;
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}
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return (bit);
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}
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static inline unsigned long
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find_first_zero_bit(unsigned long *addr, unsigned long size)
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{
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long mask;
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int bit;
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for (bit = 0; size >= BITS_PER_LONG;
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size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
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if (~(*addr) == 0)
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continue;
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return (bit + __ffsl(~(*addr)));
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}
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if (size) {
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mask = ~(*addr) & BIT_MASK(size);
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if (mask)
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bit += __ffsl(mask);
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else
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bit += size;
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}
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return (bit);
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}
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static inline unsigned long
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find_last_bit(unsigned long *addr, unsigned long size)
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{
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long mask;
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int offs;
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int bit;
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int pos;
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pos = size / BITS_PER_LONG;
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offs = size % BITS_PER_LONG;
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bit = BITS_PER_LONG * pos;
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addr += pos;
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if (offs) {
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mask = (*addr) & BIT_MASK(offs);
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if (mask)
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return (bit + __flsl(mask));
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}
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while (--pos) {
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addr--;
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bit -= BITS_PER_LONG;
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if (*addr)
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return (bit + __flsl(mask));
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}
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return (size);
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}
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static inline unsigned long
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find_next_bit(unsigned long *addr, unsigned long size, unsigned long offset)
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{
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long mask;
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int offs;
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int bit;
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int pos;
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if (offset >= size)
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return (size);
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pos = offset / BITS_PER_LONG;
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offs = offset % BITS_PER_LONG;
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bit = BITS_PER_LONG * pos;
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addr += pos;
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if (offs) {
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mask = (*addr) & ~BIT_MASK(offs);
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if (mask)
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return (bit + __ffsl(mask));
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bit += BITS_PER_LONG;
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addr++;
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}
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for (size -= bit; size >= BITS_PER_LONG;
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size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
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if (*addr == 0)
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continue;
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return (bit + __ffsl(*addr));
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}
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if (size) {
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mask = (*addr) & BIT_MASK(size);
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if (mask)
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bit += __ffsl(mask);
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else
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bit += size;
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}
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return (bit);
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}
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static inline unsigned long
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find_next_zero_bit(unsigned long *addr, unsigned long size,
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unsigned long offset)
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{
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long mask;
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int offs;
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int bit;
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int pos;
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if (offset >= size)
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return (size);
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pos = offset / BITS_PER_LONG;
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offs = offset % BITS_PER_LONG;
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bit = BITS_PER_LONG * pos;
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addr += pos;
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if (offs) {
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mask = ~(*addr) & ~BIT_MASK(offs);
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if (mask)
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return (bit + __ffsl(mask));
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bit += BITS_PER_LONG;
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addr++;
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}
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for (size -= bit; size >= BITS_PER_LONG;
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size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) {
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if (~(*addr) == 0)
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continue;
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return (bit + __ffsl(~(*addr)));
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}
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if (size) {
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mask = ~(*addr) & BIT_MASK(size);
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if (mask)
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bit += __ffsl(mask);
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else
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bit += size;
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}
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return (bit);
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}
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static inline void
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bitmap_zero(unsigned long *addr, int size)
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{
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int len;
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len = BITS_TO_LONGS(size) * sizeof(long);
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memset(addr, 0, len);
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}
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static inline void
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bitmap_fill(unsigned long *addr, int size)
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{
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int tail;
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int len;
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len = (size / BITS_PER_LONG) * sizeof(long);
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memset(addr, 0xff, len);
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tail = size & (BITS_PER_LONG - 1);
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if (tail)
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addr[size / BITS_PER_LONG] = BIT_MASK(tail);
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}
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static inline int
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bitmap_full(unsigned long *addr, int size)
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{
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long mask;
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int tail;
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int len;
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int i;
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len = size / BITS_PER_LONG;
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for (i = 0; i < len; i++)
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if (addr[i] != ~0UL)
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return (0);
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tail = size & (BITS_PER_LONG - 1);
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if (tail) {
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mask = BIT_MASK(tail);
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if ((addr[i] & mask) != mask)
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return (0);
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}
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return (1);
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}
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static inline int
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bitmap_empty(unsigned long *addr, int size)
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{
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long mask;
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int tail;
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int len;
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int i;
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len = size / BITS_PER_LONG;
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for (i = 0; i < len; i++)
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if (addr[i] != 0)
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return (0);
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tail = size & (BITS_PER_LONG - 1);
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if (tail) {
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mask = BIT_MASK(tail);
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if ((addr[i] & mask) != 0)
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return (0);
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}
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return (1);
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}
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#define NBLONG (NBBY * sizeof(long))
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#define __set_bit(i, a) \
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atomic_set_long(&((volatile long *)(a))[(i)/NBLONG], 1UL << ((i) % NBLONG))
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#define set_bit(i, a) \
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atomic_set_long(&((volatile long *)(a))[(i)/NBLONG], 1UL << ((i) % NBLONG))
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#define __clear_bit(i, a) \
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atomic_clear_long(&((volatile long *)(a))[(i)/NBLONG], 1UL << ((i) % NBLONG))
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#define clear_bit(i, a) \
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atomic_clear_long(&((volatile long *)(a))[(i)/NBLONG], 1UL << ((i) % NBLONG))
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#define test_bit(i, a) \
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!!(atomic_load_acq_long(&((volatile long *)(a))[(i)/NBLONG]) & \
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(1UL << ((i) % NBLONG)))
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static inline long
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test_and_clear_bit(long bit, long *var)
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{
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long val;
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var += bit / (sizeof(long) * NBBY);
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bit %= sizeof(long) * NBBY;
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bit = (1UL << bit);
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do {
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val = *(volatile long *)var;
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} while (atomic_cmpset_long(var, val, val & ~bit) == 0);
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return !!(val & bit);
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}
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static inline long
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test_and_set_bit(long bit, long *var)
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{
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long val;
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var += bit / (sizeof(long) * NBBY);
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bit %= sizeof(long) * NBBY;
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bit = (1UL << bit);
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do {
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val = *(volatile long *)var;
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} while (atomic_cmpset_long(var, val, val | bit) == 0);
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return !!(val & bit);
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}
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#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
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#define BITMAP_LAST_WORD_MASK(nbits) \
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( \
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((nbits) % BITS_PER_LONG) ? \
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(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \
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)
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static inline void
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bitmap_set(unsigned long *map, int start, int nr)
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{
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unsigned long *p = map + BIT_WORD(start);
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const int size = start + nr;
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int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
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unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
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while (nr - bits_to_set >= 0) {
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*p |= mask_to_set;
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nr -= bits_to_set;
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bits_to_set = BITS_PER_LONG;
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mask_to_set = ~0UL;
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p++;
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}
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if (nr) {
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mask_to_set &= BITMAP_LAST_WORD_MASK(size);
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*p |= mask_to_set;
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}
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}
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static inline void
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bitmap_clear(unsigned long *map, int start, int nr)
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{
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unsigned long *p = map + BIT_WORD(start);
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const int size = start + nr;
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int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
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unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
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while (nr - bits_to_clear >= 0) {
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*p &= ~mask_to_clear;
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nr -= bits_to_clear;
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bits_to_clear = BITS_PER_LONG;
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mask_to_clear = ~0UL;
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p++;
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}
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if (nr) {
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mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
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*p &= ~mask_to_clear;
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}
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}
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enum {
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REG_OP_ISFREE, /* true if region is all zero bits */
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REG_OP_ALLOC, /* set all bits in region */
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REG_OP_RELEASE, /* clear all bits in region */
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};
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static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
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{
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int nbits_reg; /* number of bits in region */
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int index; /* index first long of region in bitmap */
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int offset; /* bit offset region in bitmap[index] */
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int nlongs_reg; /* num longs spanned by region in bitmap */
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int nbitsinlong; /* num bits of region in each spanned long */
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unsigned long mask; /* bitmask for one long of region */
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int i; /* scans bitmap by longs */
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int ret = 0; /* return value */
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/*
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* Either nlongs_reg == 1 (for small orders that fit in one long)
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* or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
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*/
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nbits_reg = 1 << order;
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index = pos / BITS_PER_LONG;
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offset = pos - (index * BITS_PER_LONG);
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nlongs_reg = BITS_TO_LONGS(nbits_reg);
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nbitsinlong = min(nbits_reg, BITS_PER_LONG);
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/*
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* Can't do "mask = (1UL << nbitsinlong) - 1", as that
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* overflows if nbitsinlong == BITS_PER_LONG.
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*/
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mask = (1UL << (nbitsinlong - 1));
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mask += mask - 1;
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mask <<= offset;
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switch (reg_op) {
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case REG_OP_ISFREE:
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for (i = 0; i < nlongs_reg; i++) {
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if (bitmap[index + i] & mask)
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goto done;
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}
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ret = 1; /* all bits in region free (zero) */
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break;
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case REG_OP_ALLOC:
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for (i = 0; i < nlongs_reg; i++)
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bitmap[index + i] |= mask;
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break;
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case REG_OP_RELEASE:
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for (i = 0; i < nlongs_reg; i++)
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bitmap[index + i] &= ~mask;
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break;
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}
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done:
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return ret;
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}
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/**
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* bitmap_find_free_region - find a contiguous aligned mem region
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* @bitmap: array of unsigned longs corresponding to the bitmap
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* @bits: number of bits in the bitmap
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* @order: region size (log base 2 of number of bits) to find
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*
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* Find a region of free (zero) bits in a @bitmap of @bits bits and
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* allocate them (set them to one). Only consider regions of length
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* a power (@order) of two, aligned to that power of two, which
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* makes the search algorithm much faster.
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*
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* Return the bit offset in bitmap of the allocated region,
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* or -errno on failure.
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*/
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static inline int
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bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
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{
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int pos, end; /* scans bitmap by regions of size order */
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for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
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if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
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continue;
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__reg_op(bitmap, pos, order, REG_OP_ALLOC);
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return pos;
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}
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return -ENOMEM;
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}
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/**
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* bitmap_allocate_region - allocate bitmap region
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* @bitmap: array of unsigned longs corresponding to the bitmap
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* @pos: beginning of bit region to allocate
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* @order: region size (log base 2 of number of bits) to allocate
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*
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* Allocate (set bits in) a specified region of a bitmap.
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*
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* Return 0 on success, or %-EBUSY if specified region wasn't
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* free (not all bits were zero).
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*/
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static inline int
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bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
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{
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if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
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return -EBUSY;
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__reg_op(bitmap, pos, order, REG_OP_ALLOC);
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return 0;
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}
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/**
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* bitmap_release_region - release allocated bitmap region
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* @bitmap: array of unsigned longs corresponding to the bitmap
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* @pos: beginning of bit region to release
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* @order: region size (log base 2 of number of bits) to release
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*
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* This is the complement to __bitmap_find_free_region() and releases
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* the found region (by clearing it in the bitmap).
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*
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* No return value.
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*/
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static inline void
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bitmap_release_region(unsigned long *bitmap, int pos, int order)
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{
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__reg_op(bitmap, pos, order, REG_OP_RELEASE);
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}
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#define for_each_set_bit(bit, addr, size) \
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for ((bit) = find_first_bit((addr), (size)); \
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(bit) < (size); \
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(bit) = find_next_bit((addr), (size), (bit) + 1))
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#endif /* _LINUX_BITOPS_H_ */
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