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/* $NetBSD: futex.h,v 1.5 2021/09/28 15:05:42 thorpej Exp $ */
/*-
* Copyright (c) 2018, 2019 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Taylor R. Campbell and Jason R. Thorpe.
*
* 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, 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
/*-
* Copyright (c) 2005 Emmanuel Dreyfus, 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, 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Emmanuel Dreyfus
* 4. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS
* 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 _SYS_FUTEX_H_
#define _SYS_FUTEX_H_
/*
* Definitions for the __futex(2) synchronization primitive.
*
* These definitions are intended to be ABI-compatible with the
* Linux futex(2) system call.
*/
#include <sys/timespec.h>
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
#define FUTEX_FD 2
#define FUTEX_REQUEUE 3
#define FUTEX_CMP_REQUEUE 4
#define FUTEX_WAKE_OP 5
#define FUTEX_LOCK_PI 6
#define FUTEX_UNLOCK_PI 7
#define FUTEX_TRYLOCK_PI 8
#define FUTEX_WAIT_BITSET 9
#define FUTEX_WAKE_BITSET 10
#define FUTEX_WAIT_REQUEUE_PI 11
#define FUTEX_CMP_REQUEUE_PI 12
#define FUTEX_PRIVATE_FLAG __BIT(7)
#define FUTEX_CLOCK_REALTIME __BIT(8)
#define FUTEX_CMD_MASK \
(~(FUTEX_PRIVATE_FLAG|FUTEX_CLOCK_REALTIME))
#define FUTEX_OP_OP_MASK __BITS(28,31)
#define FUTEX_OP_CMP_MASK __BITS(24,27)
#define FUTEX_OP_OPARG_MASK __BITS(12,23)
#define FUTEX_OP_CMPARG_MASK __BITS(0,11)
#define FUTEX_OP(op, oparg, cmp, cmparg) \
(__SHIFTIN(op, FUTEX_OP_OP_MASK) |\
__SHIFTIN(oparg, FUTEX_OP_OPARG_MASK) |\
__SHIFTIN(cmp, FUTEX_OP_CMP_MASK) |\
__SHIFTIN(cmparg, FUTEX_OP_CMPARG_MASK))
#define FUTEX_OP_SET 0
#define FUTEX_OP_ADD 1
#define FUTEX_OP_OR 2
#define FUTEX_OP_ANDN 3
#define FUTEX_OP_XOR 4
#define FUTEX_OP_OPARG_SHIFT 8
#define FUTEX_OP_CMP_EQ 0
#define FUTEX_OP_CMP_NE 1
#define FUTEX_OP_CMP_LT 2
#define FUTEX_OP_CMP_LE 3
#define FUTEX_OP_CMP_GT 4
#define FUTEX_OP_CMP_GE 5
/*
* FUTEX_SYNCOBJ_0 and FUTEX_SYNCOBJ_1 are extensions to the Linux
* futex API that are reserved for individual consumers of futexes
* to define information specific to that synchronzation object.
* Note that as a result there is a system-wide upper limit of
* 268,435,455 threads (as opposed to 1,073,741,823).
*/
#define FUTEX_WAITERS ((int)__BIT(31))
#define FUTEX_OWNER_DIED ((int)__BIT(30))
#define FUTEX_SYNCOBJ_1 ((int)__BIT(29))
#define FUTEX_SYNCOBJ_0 ((int)__BIT(28))
#define FUTEX_TID_MASK ((int)__BITS(0,27))
#define FUTEX_BITSET_MATCH_ANY ((int)__BITS(0,31))
/*
* The robust futex ABI consists of an array of 3 longwords, the address
* of which is registered with the kernel on a per-thread basis:
*
* 0: A pointer to a singly-linked list of "lock entries". If the
* list is empty, this points back to the list itself.
*
* 1: An offset from address of the "lock entry" to the 32-bit futex
* word associated with that lock entry (may be negative).
*
* 2: A "pending" pointer, for locks that are in the process of being
* acquired or released.
*
* PI futexes are handled slightly differently. User-space indicates
* an entry is for a PI futex by setting the last-significant bit.
*/
#define _FUTEX_ROBUST_HEAD_LIST 0
#define _FUTEX_ROBUST_HEAD_OFFSET 1
#define _FUTEX_ROBUST_HEAD_PENDING 2
#define _FUTEX_ROBUST_HEAD_NWORDS 3
#define _FUTEX_ROBUST_HEAD_SIZE (_FUTEX_ROBUST_HEAD_NWORDS * \
sizeof(u_long))
#define _FUTEX_ROBUST_HEAD_SIZE32 (_FUTEX_ROBUST_HEAD_NWORDS * \
sizeof(uint32_t))
#define _FUTEX_ROBUST_ENTRY_PI __BIT(0)
#ifdef __LIBC_FUTEX_PRIVATE
struct futex_robust_list {
struct futex_robust_list *next;
};
struct futex_robust_list_head {
struct futex_robust_list list;
long futex_offset;
struct futex_robust_list *pending_list;
};
#endif /* __LIBC_FUTEX_PRIVATE */
#ifdef _KERNEL
struct lwp;
int futex_robust_head_lookup(struct lwp *, lwpid_t, void **);
void futex_release_all_lwp(struct lwp *);
int do_futex(int *, int, int, const struct timespec *, int *, int,
int, register_t *);
void futex_sys_init(void);
void futex_sys_fini(void);
#endif /* _KERNEL */
#endif /* ! _SYS_FUTEX_H_ */
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