/*- * 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_ #ifndef LOCORE #include #include #include #ifdef _KERNEL #include #include #include #endif /* _KERNEL_ */ #endif /* !LOCORE */ #include #ifdef _KERNEL /* * Mutex types and options passed to mtx_init(). MTX_QUIET 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_DUPOK 0x00000020 /* Don't log a duplicate acquire */ /* * 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 */ /* * 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_RECURSED 0x00000001 /* lock recursed (for MTX_DEF only) */ #define MTX_CONTESTED 0x00000002 /* lock contested (for MTX_DEF only) */ #define MTX_UNOWNED 0x00000004 /* Cookie for free mutex */ #define MTX_FLAGMASK ~(MTX_RECURSED | MTX_CONTESTED) #endif /* _KERNEL */ #ifndef LOCORE /* * XXX: Friendly reminder to fix things in MP code that is presently being * XXX: worked on. */ #define mp_fixme(string) #ifdef _KERNEL /* * 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. These functions should not be called directly by any * code using the API. Their macros cover their functionality. * * [See below for descriptions] * */ void mtx_init(struct mtx *m, const char *name, const char *type, int opts); void mtx_destroy(struct mtx *m); void mtx_sysinit(void *arg); void mutex_init(void); void _mtx_lock_sleep(struct mtx *m, struct thread *td, int opts, const char *file, int line); void _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line); #ifdef SMP void _mtx_lock_spin(struct mtx *m, struct thread *td, int opts, const char *file, int line); #endif void _mtx_unlock_spin(struct mtx *m, int opts, const char *file, int line); int _mtx_trylock(struct mtx *m, int opts, const char *file, int line); void _mtx_lock_flags(struct mtx *m, int opts, const char *file, int line); void _mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line); void _mtx_lock_spin_flags(struct mtx *m, int opts, const char *file, int line); void _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file, int line); #ifdef INVARIANT_SUPPORT void _mtx_assert(struct mtx *m, int what, const char *file, int line); #endif /* * We define our machine-independent (unoptimized) mutex micro-operations * here, if they are not already defined in the machine-dependent mutex.h */ /* Actually obtain mtx_lock */ #ifndef _obtain_lock #define _obtain_lock(mp, tid) \ atomic_cmpset_acq_ptr(&(mp)->mtx_lock, (void *)MTX_UNOWNED, (tid)) #endif /* Actually release mtx_lock */ #ifndef _release_lock #define _release_lock(mp, tid) \ atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), (void *)MTX_UNOWNED) #endif /* Actually release mtx_lock quickly, assuming we own it. */ #ifndef _release_lock_quick #define _release_lock_quick(mp) \ atomic_store_rel_ptr(&(mp)->mtx_lock, (void *)MTX_UNOWNED) #endif /* * Obtain a sleep lock inline, or call the "hard" function if we can't get it * easy. */ #ifndef _get_sleep_lock #define _get_sleep_lock(mp, tid, opts, file, line) do { \ struct thread *_tid = (tid); \ \ if (!_obtain_lock((mp), _tid)) \ _mtx_lock_sleep((mp), _tid, (opts), (file), (line)); \ } while (0) #endif /* * Obtain a spin lock inline, or call the "hard" function if we can't get it * easy. 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. */ #ifndef _get_spin_lock #ifdef SMP #define _get_spin_lock(mp, tid, opts, file, line) do { \ struct thread *_tid = (tid); \ \ critical_enter(); \ if (!_obtain_lock((mp), _tid)) { \ if ((mp)->mtx_lock == (uintptr_t)_tid) \ (mp)->mtx_recurse++; \ else \ _mtx_lock_spin((mp), _tid, (opts), (file), (line)); \ } \ } while (0) #else /* SMP */ #define _get_spin_lock(mp, tid, opts, file, line) do { \ struct thread *_tid = (tid); \ \ critical_enter(); \ if ((mp)->mtx_lock == (uintptr_t)_tid) \ (mp)->mtx_recurse++; \ else { \ KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \ (mp)->mtx_lock = (uintptr_t)_tid; \ } \ } while (0) #endif /* SMP */ #endif /* * Release a sleep lock inline, or call the "hard" function if we can't do it * easy. */ #ifndef _rel_sleep_lock #define _rel_sleep_lock(mp, tid, opts, file, line) do { \ if (!_release_lock((mp), (tid))) \ _mtx_unlock_sleep((mp), (opts), (file), (line)); \ } while (0) #endif /* * 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 critical_enter() when attempting to acquire a * spin lock, we need to always perform a matching critical_exit() when * releasing a spin lock. This includes the recursion cases. */ #ifndef _rel_spin_lock #ifdef SMP #define _rel_spin_lock(mp) do { \ if (mtx_recursed((mp))) \ (mp)->mtx_recurse--; \ else \ _release_lock_quick((mp)); \ critical_exit(); \ } while (0) #else /* SMP */ #define _rel_spin_lock(mp) do { \ if (mtx_recursed((mp))) \ (mp)->mtx_recurse--; \ else \ (mp)->mtx_lock = MTX_UNOWNED; \ critical_exit(); \ } while (0) #endif /* SMP */ #endif /* * 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_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_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_lockbuilder is a pool of sleep locks that is not witness * checked and should only be used for building higher level locks. * * mtxpool_sleep is a general purpose pool of sleep mutexes. */ extern struct mtx_pool *mtxpool_lockbuilder; 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) \ _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) #else /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */ #define mtx_lock_flags(m, opts) \ _get_sleep_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE) #define mtx_unlock_flags(m, opts) \ _rel_sleep_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE) #define mtx_lock_spin_flags(m, opts) \ _get_spin_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE) #define mtx_unlock_spin_flags(m, opts) \ _rel_spin_lock((m)) #endif /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */ #define mtx_trylock_flags(m, opts) \ _mtx_trylock((m), (opts), LOCK_FILE, LOCK_LINE) #define mtx_initialized(m) ((m)->mtx_object.lo_flags & LO_INITIALIZED) #define mtx_owned(m) (((m)->mtx_lock & MTX_FLAGMASK) == (uintptr_t)curthread) #define mtx_recursed(m) ((m)->mtx_recurse != 0) #define mtx_name(m) ((m)->mtx_object.lo_name) /* * Global locks. */ extern struct mtx sched_lock; extern struct mtx Giant; /* * 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; \ WITNESS_SAVE_DECL(Giant); \ \ if (mtx_owned(&Giant)) \ WITNESS_SAVE(&Giant.mtx_object, Giant); \ for (_giantcnt = 0; mtx_owned(&Giant); _giantcnt++) \ mtx_unlock(&Giant) #define PICKUP_GIANT() \ mtx_assert(&Giant, MA_NOTOWNED); \ while (_giantcnt--) \ mtx_lock(&Giant); \ if (mtx_owned(&Giant)) \ WITNESS_RESTORE(&Giant.mtx_object, Giant); \ } while (0) #define PARTIAL_PICKUP_GIANT() \ mtx_assert(&Giant, MA_NOTOWNED); \ while (_giantcnt--) \ mtx_lock(&Giant); \ if (mtx_owned(&Giant)) \ WITNESS_RESTORE(&Giant.mtx_object, Giant) #endif /* * Network MPSAFE temporary workarounds. When debug_mpsafenet * is 1 the network is assumed to operate without Giant on the * input path and protocols that require Giant must collect it * on entry. When 0 Giant is grabbed in the network interface * ISR's and in the netisr path and there is no need to grab * the Giant lock. Note that, unlike GIANT_PICKUP() and * GIANT_DROP(), these macros directly wrap mutex operations * without special recursion handling. * * This mechanism is intended as temporary until everything of * importance is properly locked. Note: the semantics for * NET_{LOCK,UNLOCK}_GIANT() are not the same as DROP_GIANT() * and PICKUP_GIANT(), as they are plain mutex operations * without a recursion counter. */ extern int debug_mpsafenet; /* defined in net/netisr.c */ #define NET_LOCK_GIANT() do { \ if (!debug_mpsafenet) \ mtx_lock(&Giant); \ } while (0) #define NET_UNLOCK_GIANT() do { \ if (!debug_mpsafenet) \ mtx_unlock(&Giant); \ } while (0) #define NET_ASSERT_GIANT() do { \ if (!debug_mpsafenet) \ mtx_assert(&Giant, MA_OWNED); \ } while (0) #define UGAR(rval) do { \ int _val = (rval); \ mtx_unlock(&Giant); \ return (_val); \ } while (0) struct mtx_args { struct mtx *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) /* * 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. */ #ifdef INVARIANT_SUPPORT #define MA_OWNED 0x01 #define MA_NOTOWNED 0x02 #define MA_RECURSED 0x04 #define MA_NOTRECURSED 0x08 #endif /* INVARIANT_SUPPORT */ #ifdef INVARIANTS #define mtx_assert(m, what) \ _mtx_assert((m), (what), __FILE__, __LINE__) #define GIANT_REQUIRED mtx_assert(&Giant, MA_OWNED) #else /* INVARIANTS */ #define mtx_assert(m, what) #define GIANT_REQUIRED #endif /* INVARIANTS */ /* * Common lock type names. */ #define MTX_NETWORK_LOCK "network driver" #endif /* _KERNEL */ #endif /* !LOCORE */ #endif /* _SYS_MUTEX_H_ */