xnu-4903.270.47.tar.gz

[apple/xnu.git] / bsd / sys / ulock.h

/*
 * Copyright (c) 2015 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
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 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#ifndef _SYS_ULOCK_H
#define _SYS_ULOCK_H

__BEGIN_DECLS

#if PRIVATE

#ifdef XNU_KERNEL_PRIVATE
extern mach_port_name_t ipc_entry_name_mask(mach_port_name_t name);

static __inline mach_port_name_t
ulock_owner_value_to_port_name(uint32_t uval)
{
	/*
	 * userland uses the least significant bits for flags as these are
	 * never used in the mach port name, and are generally always set by
	 * the ipc_entry code in the kernel. Here we reconstruct a mach port
	 * name that we can use in the kernel.
	 */
	return ipc_entry_name_mask((mach_port_name_t)uval);
}
#else
static __inline mach_port_name_t
ulock_owner_value_to_port_name(uint32_t uval)
{
	return uval | 0x3;
}
#endif

#ifndef KERNEL

extern int __ulock_wait(uint32_t operation, void *addr, uint64_t value,
    uint32_t timeout);             /* timeout is specified in microseconds */
extern int __ulock_wake(uint32_t operation, void *addr, uint64_t wake_value);

#endif /* !KERNEL */

/*
 * operation bits [7, 0] contain the operation code
 */
#define UL_COMPARE_AND_WAIT                             1
#define UL_UNFAIR_LOCK                                  2
/* obsolete names */
#define UL_OSSPINLOCK                                   UL_COMPARE_AND_WAIT
#define UL_HANDOFFLOCK                                  UL_UNFAIR_LOCK
/* These operation code are only implemented in (DEVELOPMENT || DEBUG) kernels */
#define UL_DEBUG_SIMULATE_COPYIN_FAULT  253
#define UL_DEBUG_HASH_DUMP_ALL                  254
#define UL_DEBUG_HASH_DUMP_PID                  255

/*
 * operation bits [15, 8] contain the flags for __ulock_wake
 */
#define ULF_WAKE_ALL                                    0x00000100
#define ULF_WAKE_THREAD                                 0x00000200

/*
 * operation bits [23, 16] contain the flags for __ulock_wait
 *
 * @const ULF_WAIT_WORKQ_DATA_CONTENTION
 * The waiter is contending on this lock for synchronization around global data.
 * This causes the workqueue subsystem to not create new threads to offset for
 * waiters on this lock.
 *
 * @const ULF_WAIT_CANCEL_POINT
 * This wait is a cancelation point
 */
#define ULF_WAIT_WORKQ_DATA_CONTENTION  0x00010000
#define ULF_WAIT_CANCEL_POINT           0x00020000

/*
 * operation bits [31, 24] contain the generic flags
 */
#define ULF_NO_ERRNO                                    0x01000000

/*
 * masks
 */
#define UL_OPCODE_MASK          0x000000FF
#define UL_FLAGS_MASK           0xFFFFFF00
#define ULF_GENERIC_MASK        0xFFFF0000

#define ULF_WAIT_MASK           (ULF_NO_ERRNO | \
	                                                 ULF_WAIT_WORKQ_DATA_CONTENTION | \
	                                                 ULF_WAIT_CANCEL_POINT)

#define ULF_WAKE_MASK           (ULF_WAKE_ALL | \
	                                                 ULF_WAKE_THREAD | \
	                                                 ULF_NO_ERRNO)

#endif /* PRIVATE */

__END_DECLS

#endif