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Diffstat (limited to 'include/sys/bitops.h')
| -rw-r--r-- | include/sys/bitops.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/include/sys/bitops.h b/include/sys/bitops.h new file mode 100644 index 000000000000..56d52073bcc8 --- /dev/null +++ b/include/sys/bitops.h @@ -0,0 +1,90 @@ +/* + * 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 */ |