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/**
* \file drm_atomic.h
* Atomic operations used in the DRM which may or may not be provided by the OS.
*
* \author Eric Anholt <anholt@FreeBSD.org>
*/
/*-
* Copyright 2004 Eric Anholt
* Copyright 2013 Jung-uk Kim <jkim@FreeBSD.org>
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
typedef u_int atomic_t;
typedef uint64_t atomic64_t;
#define BITS_PER_LONG (sizeof(long) * NBBY)
#define BITS_TO_LONGS(x) howmany(x, BITS_PER_LONG)
#define atomic_read(p) (*(volatile u_int *)(p))
#define atomic_set(p, v) do { *(u_int *)(p) = (v); } while (0)
#define atomic_add(v, p) atomic_add_int(p, v)
#define atomic_sub(v, p) atomic_subtract_int(p, v)
#define atomic_inc(p) atomic_add(1, p)
#define atomic_dec(p) atomic_sub(1, p)
#define atomic_add_return(v, p) (atomic_fetchadd_int(p, v) + (v))
#define atomic_sub_return(v, p) (atomic_fetchadd_int(p, -(v)) - (v))
#define atomic_inc_return(p) atomic_add_return(1, p)
#define atomic_dec_return(p) atomic_sub_return(1, p)
#define atomic_add_and_test(v, p) (atomic_add_return(v, p) == 0)
#define atomic_sub_and_test(v, p) (atomic_sub_return(v, p) == 0)
#define atomic_inc_and_test(p) (atomic_inc_return(p) == 0)
#define atomic_dec_and_test(p) (atomic_dec_return(p) == 0)
#define atomic_xchg(p, v) atomic_swap_int(p, v)
#define atomic64_xchg(p, v) atomic_swap_64(p, v)
#define __bit_word(b) ((b) / BITS_PER_LONG)
#define __bit_mask(b) (1UL << (b) % BITS_PER_LONG)
#define __bit_addr(p, b) ((volatile u_long *)(p) + __bit_word(b))
#define clear_bit(b, p) \
atomic_clear_long(__bit_addr(p, b), __bit_mask(b))
#define set_bit(b, p) \
atomic_set_long(__bit_addr(p, b), __bit_mask(b))
#define test_bit(b, p) \
((*__bit_addr(p, b) & __bit_mask(b)) != 0)
static __inline u_long
find_first_zero_bit(const u_long *p, u_long max)
{
u_long i, n;
KASSERT(max % BITS_PER_LONG == 0, ("invalid bitmap size %lu", max));
for (i = 0; i < max / BITS_PER_LONG; i++) {
n = ~p[i];
if (n != 0)
return (i * BITS_PER_LONG + ffsl(n) - 1);
}
return (max);
}
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