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freebsd/sys/ofed/include/linux/bitops.h
Hans Petter Selasky 7c3892fc82 Add more functions to the Linux kernel compatibility layer. Add some 
missing includes which are needed when the header files are not
included in a particular order.

MFC after:	1 month
Sponsored by:	Mellanox Technologies
2015-01-19 20:39:48 +00:00

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