zfs-builds-mm/zfs-2.0.0-rc4/include/sys/bitops.h
2020-10-22 14:20:35 +02:00

90 lines
3.2 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011, 2019 by Delphix. All rights reserved.
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
* Copyright 2013 Saso Kiselkov. All rights reserved.
* Copyright (c) 2014 Integros [integros.com]
* Copyright 2017 Joyent, Inc.
* Copyright (c) 2017 Datto Inc.
*/
#ifndef _SYS_BITOPS_H
#define _SYS_BITOPS_H
#include <sys/zfs_context.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* General-purpose 32-bit and 64-bit bitfield encodings.
*/
#define BF32_DECODE(x, low, len) P2PHASE((x) >> (low), 1U << (len))
#define BF64_DECODE(x, low, len) P2PHASE((x) >> (low), 1ULL << (len))
#define BF32_ENCODE(x, low, len) (P2PHASE((x), 1U << (len)) << (low))
#define BF64_ENCODE(x, low, len) (P2PHASE((x), 1ULL << (len)) << (low))
#define BF32_GET(x, low, len) BF32_DECODE(x, low, len)
#define BF64_GET(x, low, len) BF64_DECODE(x, low, len)
#define BF32_SET(x, low, len, val) do { \
ASSERT3U(val, <, 1U << (len)); \
ASSERT3U(low + len, <=, 32); \
(x) ^= BF32_ENCODE((x >> low) ^ (val), low, len); \
_NOTE(CONSTCOND) } while (0)
#define BF64_SET(x, low, len, val) do { \
ASSERT3U(val, <, 1ULL << (len)); \
ASSERT3U(low + len, <=, 64); \
((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)); \
_NOTE(CONSTCOND) } while (0)
#define BF32_GET_SB(x, low, len, shift, bias) \
((BF32_GET(x, low, len) + (bias)) << (shift))
#define BF64_GET_SB(x, low, len, shift, bias) \
((BF64_GET(x, low, len) + (bias)) << (shift))
/*
* We use ASSERT3U instead of ASSERT in these macros to prevent a lint error in
* the case where val is a constant. We can't fix ASSERT because it's used as
* an expression in several places in the kernel; as a result, changing it to
* the do{} while() syntax to allow us to _NOTE the CONSTCOND is not an option.
*/
#define BF32_SET_SB(x, low, len, shift, bias, val) do { \
ASSERT3U(IS_P2ALIGNED(val, 1U << shift), !=, B_FALSE); \
ASSERT3S((val) >> (shift), >=, bias); \
BF32_SET(x, low, len, ((val) >> (shift)) - (bias)); \
_NOTE(CONSTCOND) } while (0)
#define BF64_SET_SB(x, low, len, shift, bias, val) do { \
ASSERT3U(IS_P2ALIGNED(val, 1ULL << shift), !=, B_FALSE); \
ASSERT3S((val) >> (shift), >=, bias); \
BF64_SET(x, low, len, ((val) >> (shift)) - (bias)); \
_NOTE(CONSTCOND) } while (0)
#ifdef __cplusplus
}
#endif
#endif /* _SYS_BITOPS_H */