/* $NetBSD: mutex.h,v 1.15.26.1 2023/08/09 17:42:02 martin Exp $ */ /*- * Copyright (c) 2002, 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe and Andrew Doran. * * 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. */ #ifndef _HPPA_MUTEX_H_ #define _HPPA_MUTEX_H_ /* * The HPPA mutex implementation is troublesome, because HPPA lacks * a compare-and-set operation, yet there are many SMP HPPA machines * in circulation. SMP for spin mutexes is easy - we don't need to * know who owns the lock. For adaptive mutexes, we need an owner * field and additional interlock */ #ifndef __ASSEMBLER__ #include #ifdef __MUTEX_PRIVATE #include #include #endif struct kmutex { union { /* * Only the 16 bytes aligned word of __cpu_simple_lock_t will * be used. It's 16 bytes to simplify the allocation. * See hppa/lock.h */ #ifdef __MUTEX_PRIVATE struct { __cpu_simple_lock_t mtxu_lock; /* 0-15 */ volatile uint32_t mtxs_owner; /* 16-19 */ ipl_cookie_t mtxs_ipl; /* 20-23 */ volatile uint8_t mtxs_waiters; /* 24 */ /* For LOCKDEBUG */ uint8_t mtxs_dodebug; /* 25 */ } s; #endif uint8_t mtxu_pad[32]; /* 0 - 32 */ } u; } __aligned (16); #endif #ifdef __MUTEX_PRIVATE #define __HAVE_MUTEX_STUBS 1 #define mtx_lock u.s.mtxu_lock #define mtx_owner u.s.mtxs_owner #define mtx_ipl u.s.mtxs_ipl #define mtx_waiters u.s.mtxs_waiters #define mtx_dodebug u.s.mtxs_dodebug /* Magic constants for mtx_owner */ #define MUTEX_ADAPTIVE_UNOWNED 0xffffff00 #define MUTEX_SPIN_FLAG 0xffffff10 #define MUTEX_UNOWNED_OR_SPIN(x) (((x) & 0xffffffef) == 0xffffff00) #if !defined(__ASSEMBLER__) && defined(_KERNEL) static inline uintptr_t MUTEX_OWNER(uintptr_t owner) { return owner; } static inline int MUTEX_OWNED(uintptr_t owner) { return owner != MUTEX_ADAPTIVE_UNOWNED; } static inline int MUTEX_SET_WAITERS(struct kmutex *mtx, uintptr_t owner) { __sync(); /* formerly mb_read */ mtx->mtx_waiters = 1; __sync(); /* formerly mb_memory */ return mtx->mtx_owner != MUTEX_ADAPTIVE_UNOWNED; } static inline int MUTEX_HAS_WAITERS(const volatile struct kmutex *mtx) { return mtx->mtx_waiters != 0; } static inline void MUTEX_INITIALIZE_SPIN(struct kmutex *mtx, bool dodebug, int ipl) { mtx->mtx_ipl = makeiplcookie(ipl); mtx->mtx_dodebug = dodebug; mtx->mtx_owner = MUTEX_SPIN_FLAG; __cpu_simple_lock_init(&mtx->mtx_lock); } static inline void MUTEX_INITIALIZE_ADAPTIVE(struct kmutex *mtx, bool dodebug) { mtx->mtx_dodebug = dodebug; mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; __cpu_simple_lock_init(&mtx->mtx_lock); } static inline void MUTEX_DESTROY(struct kmutex *mtx) { mtx->mtx_owner = 0xffffffff; } static inline bool MUTEX_DEBUG_P(const volatile struct kmutex *mtx) { return mtx->mtx_dodebug != 0; } static inline int MUTEX_SPIN_P(const uintptr_t owner) { return owner == MUTEX_SPIN_FLAG; } static inline int MUTEX_ADAPTIVE_P(const uintptr_t owner) { return owner != MUTEX_SPIN_FLAG; } /* Acquire an adaptive mutex */ static inline int MUTEX_ACQUIRE(struct kmutex *mtx, uintptr_t curthread) { if (!__cpu_simple_lock_try(&mtx->mtx_lock)) return 0; mtx->mtx_owner = curthread; return 1; } /* Release an adaptive mutex */ static inline void MUTEX_RELEASE(struct kmutex *mtx) { mtx->mtx_owner = MUTEX_ADAPTIVE_UNOWNED; __cpu_simple_unlock(&mtx->mtx_lock); mtx->mtx_waiters = 0; } static inline void MUTEX_CLEAR_WAITERS(struct kmutex *mtx) { mtx->mtx_waiters = 0; } #endif /* !__ASSEMBLER__ && _KERNEL */ #endif /* __MUTEX_PRIVATE */ #endif /* _HPPA_MUTEX_H_ */