/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1997 Berkeley Software Design, Inc. 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. Berkeley Software Design Inc's name may not be used to endorse or * promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``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 BERKELEY SOFTWARE DESIGN INC 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. * * from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $ * $FreeBSD$ */ #ifndef _SYS_MUTEX_H_ #define _SYS_MUTEX_H_ #include #include #include #ifdef _KERNEL #include #include #include #include #include /* * Mutex types and options passed to mtx_init(). MTX_QUIET and MTX_DUPOK * can also be passed in. */ #define MTX_DEF 0x00000000 /* DEFAULT (sleep) lock */ #define MTX_SPIN 0x00000001 /* Spin lock (disables interrupts) */ #define MTX_RECURSE 0x00000004 /* Option: lock allowed to recurse */ #define MTX_NOWITNESS 0x00000008 /* Don't do any witness checking. */ #define MTX_NOPROFILE 0x00000020 /* Don't profile this lock */ #define MTX_NEW 0x00000040 /* Don't check for double-init */ /* * Option flags passed to certain lock/unlock routines, through the use * of corresponding mtx_{lock,unlock}_flags() interface macros. */ #define MTX_QUIET LOP_QUIET /* Don't log a mutex event */ #define MTX_DUPOK LOP_DUPOK /* Don't log a duplicate acquire */ /* * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this, * with the exception of MTX_UNOWNED, applies to spin locks. */ #define MTX_UNOWNED 0x00000000 /* Cookie for free mutex */ #define MTX_RECURSED 0x00000001 /* lock recursed (for MTX_DEF only) */ #define MTX_CONTESTED 0x00000002 /* lock contested (for MTX_DEF only) */ #define MTX_DESTROYED 0x00000004 /* lock destroyed */ #define MTX_FLAGMASK (MTX_RECURSED | MTX_CONTESTED | MTX_DESTROYED) /* * Prototypes * * NOTE: Functions prepended with `_' (underscore) are exported to other parts * of the kernel via macros, thus allowing us to use the cpp LOCK_FILE * and LOCK_LINE or for hiding the lock cookie crunching to the * consumers. These functions should not be called directly by any * code using the API. Their macros cover their functionality. * Functions with a `_' suffix are the entrypoint for the common * KPI covering both compat shims and fast path case. These can be * used by consumers willing to pass options, file and line * informations, in an option-independent way. * * [See below for descriptions] * */ void _mtx_init(volatile uintptr_t *c, const char *name, const char *type, int opts); void _mtx_destroy(volatile uintptr_t *c); void mtx_sysinit(void *arg); int _mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF); int _mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, int line); void mutex_init(void); #if LOCK_DEBUG > 0 void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, const char *file, int line); void __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, const char *file, int line); #else void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v); void __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v); #endif void mtx_wait_unlocked(struct mtx *m); #ifdef SMP #if LOCK_DEBUG > 0 void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, int opts, const char *file, int line); #else void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v); #endif #endif void __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line); void __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, int line); void __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line); int __mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line); void __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line); void mtx_spin_wait_unlocked(struct mtx *m); #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) void __mtx_assert(const volatile uintptr_t *c, int what, const char *file, int line); #endif void thread_lock_flags_(struct thread *, int, const char *, int); #if LOCK_DEBUG > 0 void _thread_lock(struct thread *td, int opts, const char *file, int line); #else void _thread_lock(struct thread *); #endif #if defined(LOCK_PROFILING) || (defined(KLD_MODULE) && !defined(KLD_TIED)) #define thread_lock(tdp) \ thread_lock_flags_((tdp), 0, __FILE__, __LINE__) #elif LOCK_DEBUG > 0 #define thread_lock(tdp) \ _thread_lock((tdp), 0, __FILE__, __LINE__) #else #define thread_lock(tdp) \ _thread_lock((tdp)) #endif #if LOCK_DEBUG > 0 #define thread_lock_flags(tdp, opt) \ thread_lock_flags_((tdp), (opt), __FILE__, __LINE__) #else #define thread_lock_flags(tdp, opt) \ _thread_lock(tdp) #endif #define thread_unlock(tdp) \ mtx_unlock_spin((tdp)->td_lock) /* * Top-level macros to provide lock cookie once the actual mtx is passed. * They will also prevent passing a malformed object to the mtx KPI by * failing compilation as the mtx_lock reserved member will not be found. */ #define mtx_init(m, n, t, o) \ _mtx_init(&(m)->mtx_lock, n, t, o) #define mtx_destroy(m) \ _mtx_destroy(&(m)->mtx_lock) #define mtx_trylock_flags_(m, o, f, l) \ _mtx_trylock_flags_(&(m)->mtx_lock, o, f, l) #if LOCK_DEBUG > 0 #define _mtx_lock_sleep(m, v, o, f, l) \ __mtx_lock_sleep(&(m)->mtx_lock, v, o, f, l) #define _mtx_unlock_sleep(m, v, o, f, l) \ __mtx_unlock_sleep(&(m)->mtx_lock, v, o, f, l) #else #define _mtx_lock_sleep(m, v, o, f, l) \ __mtx_lock_sleep(&(m)->mtx_lock, v) #define _mtx_unlock_sleep(m, v, o, f, l) \ __mtx_unlock_sleep(&(m)->mtx_lock, v) #endif #ifdef SMP #if LOCK_DEBUG > 0 #define _mtx_lock_spin(m, v, o, f, l) \ _mtx_lock_spin_cookie(&(m)->mtx_lock, v, o, f, l) #else #define _mtx_lock_spin(m, v, o, f, l) \ _mtx_lock_spin_cookie(&(m)->mtx_lock, v) #endif #endif #define _mtx_lock_flags(m, o, f, l) \ __mtx_lock_flags(&(m)->mtx_lock, o, f, l) #define _mtx_unlock_flags(m, o, f, l) \ __mtx_unlock_flags(&(m)->mtx_lock, o, f, l) #define _mtx_lock_spin_flags(m, o, f, l) \ __mtx_lock_spin_flags(&(m)->mtx_lock, o, f, l) #define _mtx_trylock_spin_flags(m, o, f, l) \ __mtx_trylock_spin_flags(&(m)->mtx_lock, o, f, l) #define _mtx_unlock_spin_flags(m, o, f, l) \ __mtx_unlock_spin_flags(&(m)->mtx_lock, o, f, l) #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) #define _mtx_assert(m, w, f, l) \ __mtx_assert(&(m)->mtx_lock, w, f, l) #endif #define mtx_recurse lock_object.lo_data /* Very simple operations on mtx_lock. */ /* Try to obtain mtx_lock once. */ #define _mtx_obtain_lock(mp, tid) \ atomic_cmpset_acq_ptr(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) #define _mtx_obtain_lock_fetch(mp, vp, tid) \ atomic_fcmpset_acq_ptr(&(mp)->mtx_lock, vp, (tid)) /* Try to release mtx_lock if it is unrecursed and uncontested. */ #define _mtx_release_lock(mp, tid) \ atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), MTX_UNOWNED) /* Release mtx_lock quickly, assuming we own it. */ #define _mtx_release_lock_quick(mp) \ atomic_store_rel_ptr(&(mp)->mtx_lock, MTX_UNOWNED) #define _mtx_release_lock_fetch(mp, vp) \ atomic_fcmpset_rel_ptr(&(mp)->mtx_lock, (vp), MTX_UNOWNED) /* * Full lock operations that are suitable to be inlined in non-debug * kernels. If the lock cannot be acquired or released trivially then * the work is deferred to another function. */ /* Lock a normal mutex. */ #define __mtx_lock(mp, tid, opts, file, line) do { \ uintptr_t _tid = (uintptr_t)(tid); \ uintptr_t _v = MTX_UNOWNED; \ \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__acquire) ||\ !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \ _mtx_lock_sleep((mp), _v, (opts), (file), (line)); \ } while (0) /* * Lock a spin mutex. For spinlocks, we handle recursion inline (it * turns out that function calls can be significantly expensive on * some architectures). Since spin locks are not _too_ common, * inlining this code is not too big a deal. */ #ifdef SMP #define __mtx_lock_spin(mp, tid, opts, file, line) do { \ uintptr_t _tid = (uintptr_t)(tid); \ uintptr_t _v = MTX_UNOWNED; \ \ spinlock_enter(); \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire) || \ !_mtx_obtain_lock_fetch((mp), &_v, _tid))) \ _mtx_lock_spin((mp), _v, (opts), (file), (line)); \ } while (0) #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ int _ret; \ \ spinlock_enter(); \ if (((mp)->mtx_lock != MTX_UNOWNED || !_mtx_obtain_lock((mp), _tid))) {\ spinlock_exit(); \ _ret = 0; \ } else { \ LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, \ mp, 0, 0, file, line); \ _ret = 1; \ } \ _ret; \ }) #else /* SMP */ #define __mtx_lock_spin(mp, tid, opts, file, line) do { \ uintptr_t _tid = (uintptr_t)(tid); \ \ spinlock_enter(); \ if ((mp)->mtx_lock == _tid) \ (mp)->mtx_recurse++; \ else { \ KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \ (mp)->mtx_lock = _tid; \ } \ } while (0) #define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__ ({ \ uintptr_t _tid = (uintptr_t)(tid); \ int _ret; \ \ spinlock_enter(); \ if ((mp)->mtx_lock != MTX_UNOWNED) { \ spinlock_exit(); \ _ret = 0; \ } else { \ (mp)->mtx_lock = _tid; \ _ret = 1; \ } \ _ret; \ }) #endif /* SMP */ /* Unlock a normal mutex. */ #define __mtx_unlock(mp, tid, opts, file, line) do { \ uintptr_t _v = (uintptr_t)(tid); \ \ if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__release) ||\ !_mtx_release_lock_fetch((mp), &_v))) \ _mtx_unlock_sleep((mp), _v, (opts), (file), (line)); \ } while (0) /* * Unlock a spin mutex. For spinlocks, we can handle everything * inline, as it's pretty simple and a function call would be too * expensive (at least on some architectures). Since spin locks are * not _too_ common, inlining this code is not too big a deal. * * Since we always perform a spinlock_enter() when attempting to acquire a * spin lock, we need to always perform a matching spinlock_exit() when * releasing a spin lock. This includes the recursion cases. */ #ifdef SMP #define __mtx_unlock_spin(mp) do { \ if (mtx_recursed((mp))) \ (mp)->mtx_recurse--; \ else { \ LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp); \ _mtx_release_lock_quick((mp)); \ } \ spinlock_exit(); \ } while (0) #else /* SMP */ #define __mtx_unlock_spin(mp) do { \ if (mtx_recursed((mp))) \ (mp)->mtx_recurse--; \ else { \ LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp); \ (mp)->mtx_lock = MTX_UNOWNED; \ } \ spinlock_exit(); \ } while (0) #endif /* SMP */ /* * Exported lock manipulation interface. * * mtx_lock(m) locks MTX_DEF mutex `m' * * mtx_lock_spin(m) locks MTX_SPIN mutex `m' * * mtx_unlock(m) unlocks MTX_DEF mutex `m' * * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m' * * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m' * and passes option flags `opts' to the "hard" function, if required. * With these routines, it is possible to pass flags such as MTX_QUIET * to the appropriate lock manipulation routines. * * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if * it cannot. Rather, it returns 0 on failure and non-zero on success. * It does NOT handle recursion as we assume that if a caller is properly * using this part of the interface, he will know that the lock in question * is _not_ recursed. * * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts * relevant option flags `opts.' * * mtx_trylock_spin(m) attempts to acquire MTX_SPIN mutex `m' but doesn't * spin if it cannot. Rather, it returns 0 on failure and non-zero on * success. It always returns failure for recursed lock attempts. * * mtx_initialized(m) returns non-zero if the lock `m' has been initialized. * * mtx_owned(m) returns non-zero if the current thread owns the lock `m' * * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed. */ #define mtx_lock(m) mtx_lock_flags((m), 0) #define mtx_lock_spin(m) mtx_lock_spin_flags((m), 0) #define mtx_trylock(m) mtx_trylock_flags((m), 0) #define mtx_trylock_spin(m) mtx_trylock_spin_flags((m), 0) #define mtx_unlock(m) mtx_unlock_flags((m), 0) #define mtx_unlock_spin(m) mtx_unlock_spin_flags((m), 0) struct mtx_pool; struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts); void mtx_pool_destroy(struct mtx_pool **poolp); struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr); struct mtx *mtx_pool_alloc(struct mtx_pool *pool); #define mtx_pool_lock(pool, ptr) \ mtx_lock(mtx_pool_find((pool), (ptr))) #define mtx_pool_lock_spin(pool, ptr) \ mtx_lock_spin(mtx_pool_find((pool), (ptr))) #define mtx_pool_unlock(pool, ptr) \ mtx_unlock(mtx_pool_find((pool), (ptr))) #define mtx_pool_unlock_spin(pool, ptr) \ mtx_unlock_spin(mtx_pool_find((pool), (ptr))) /* * mtxpool_sleep is a general purpose pool of sleep mutexes. */ extern struct mtx_pool *mtxpool_sleep; #ifndef LOCK_DEBUG #error LOCK_DEBUG not defined, include before #endif #if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE) #define mtx_lock_flags_(m, opts, file, line) \ _mtx_lock_flags((m), (opts), (file), (line)) #define mtx_unlock_flags_(m, opts, file, line) \ _mtx_unlock_flags((m), (opts), (file), (line)) #define mtx_lock_spin_flags_(m, opts, file, line) \ _mtx_lock_spin_flags((m), (opts), (file), (line)) #define mtx_trylock_spin_flags_(m, opts, file, line) \ _mtx_trylock_spin_flags((m), (opts), (file), (line)) #define mtx_unlock_spin_flags_(m, opts, file, line) \ _mtx_unlock_spin_flags((m), (opts), (file), (line)) #else /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */ #define mtx_lock_flags_(m, opts, file, line) \ __mtx_lock((m), curthread, (opts), (file), (line)) #define mtx_unlock_flags_(m, opts, file, line) \ __mtx_unlock((m), curthread, (opts), (file), (line)) #define mtx_lock_spin_flags_(m, opts, file, line) \ __mtx_lock_spin((m), curthread, (opts), (file), (line)) #define mtx_trylock_spin_flags_(m, opts, file, line) \ __mtx_trylock_spin((m), curthread, (opts), (file), (line)) #define mtx_unlock_spin_flags_(m, opts, file, line) \ __mtx_unlock_spin((m)) #endif /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */ #ifdef INVARIANTS #define mtx_assert_(m, what, file, line) \ _mtx_assert((m), (what), (file), (line)) #define GIANT_REQUIRED mtx_assert_(&Giant, MA_OWNED, __FILE__, __LINE__) #else /* INVARIANTS */ #define mtx_assert_(m, what, file, line) (void)0 #define GIANT_REQUIRED #endif /* INVARIANTS */ #define mtx_lock_flags(m, opts) \ mtx_lock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_unlock_flags(m, opts) \ mtx_unlock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_lock_spin_flags(m, opts) \ mtx_lock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_unlock_spin_flags(m, opts) \ mtx_unlock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_trylock_flags(m, opts) \ mtx_trylock_flags_((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_trylock_spin_flags(m, opts) \ mtx_trylock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_assert(m, what) \ mtx_assert_((m), (what), __FILE__, __LINE__) #define mtx_sleep(chan, mtx, pri, wmesg, timo) \ _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), \ tick_sbt * (timo), 0, C_HARDCLOCK) #define MTX_READ_VALUE(m) ((m)->mtx_lock) #define mtx_initialized(m) lock_initialized(&(m)->lock_object) #define lv_mtx_owner(v) ((struct thread *)((v) & ~MTX_FLAGMASK)) #define mtx_owner(m) lv_mtx_owner(MTX_READ_VALUE(m)) #define mtx_owned(m) (mtx_owner(m) == curthread) #define mtx_recursed(m) ((m)->mtx_recurse != 0) #define mtx_name(m) ((m)->lock_object.lo_name) /* * Global locks. */ extern struct mtx Giant; extern struct mtx blocked_lock; /* * Giant lock manipulation and clean exit macros. * Used to replace return with an exit Giant and return. * * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT() * The #ifndef is to allow lint-like tools to redefine DROP_GIANT. */ #ifndef DROP_GIANT #define DROP_GIANT() \ do { \ int _giantcnt = 0; \ WITNESS_SAVE_DECL(Giant); \ \ if (__predict_false(mtx_owned(&Giant))) { \ WITNESS_SAVE(&Giant.lock_object, Giant); \ for (_giantcnt = 0; mtx_owned(&Giant) && \ !SCHEDULER_STOPPED(); _giantcnt++) \ mtx_unlock(&Giant); \ } #define PICKUP_GIANT() \ PARTIAL_PICKUP_GIANT(); \ } while (0) #define PARTIAL_PICKUP_GIANT() \ mtx_assert(&Giant, MA_NOTOWNED); \ if (__predict_false(_giantcnt > 0)) { \ while (_giantcnt--) \ mtx_lock(&Giant); \ WITNESS_RESTORE(&Giant.lock_object, Giant); \ } #endif struct mtx_args { void *ma_mtx; const char *ma_desc; int ma_opts; }; #define MTX_SYSINIT(name, mtx, desc, opts) \ static struct mtx_args name##_args = { \ (mtx), \ (desc), \ (opts) \ }; \ SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ mtx_sysinit, &name##_args); \ SYSUNINIT(name##_mtx_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE, \ _mtx_destroy, __DEVOLATILE(void *, &(mtx)->mtx_lock)) /* * The INVARIANTS-enabled mtx_assert() functionality. * * The constants need to be defined for INVARIANT_SUPPORT infrastructure * support as _mtx_assert() itself uses them and the latter implies that * _mtx_assert() must build. */ #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT) #define MA_OWNED LA_XLOCKED #define MA_NOTOWNED LA_UNLOCKED #define MA_RECURSED LA_RECURSED #define MA_NOTRECURSED LA_NOTRECURSED #endif /* * Common lock type names. */ #define MTX_NETWORK_LOCK "network driver" #endif /* _KERNEL */ #endif /* _SYS_MUTEX_H_ */