xref: /dragonfly/sys/sys/thread.h (revision d4ef6694)
1 /*
2  * SYS/THREAD.H
3  *
4  *	Implements the architecture independant portion of the LWKT
5  *	subsystem.
6  *
7  * Types which must already be defined when this header is included by
8  * userland:	struct md_thread
9  */
10 
11 #ifndef _SYS_THREAD_H_
12 #define _SYS_THREAD_H_
13 
14 #ifndef _SYS_STDINT_H_
15 #include <sys/stdint.h>		/* __int types */
16 #endif
17 #ifndef _SYS_PARAM_H_
18 #include <sys/param.h>		/* MAXCOMLEN */
19 #endif
20 #ifndef _SYS_QUEUE_H_
21 #include <sys/queue.h>		/* TAILQ_* macros */
22 #endif
23 #ifndef _SYS_MSGPORT_H_
24 #include <sys/msgport.h>	/* lwkt_port */
25 #endif
26 #ifndef _SYS_TIME_H_
27 #include <sys/time.h>   	/* struct timeval */
28 #endif
29 #ifndef _SYS_LOCK_H
30 #include <sys/lock.h>
31 #endif
32 #ifndef _SYS_SPINLOCK_H_
33 #include <sys/spinlock.h>
34 #endif
35 #ifndef _SYS_IOSCHED_H_
36 #include <sys/iosched.h>
37 #endif
38 #include <machine/thread.h>
39 
40 struct globaldata;
41 struct lwp;
42 struct proc;
43 struct thread;
44 struct lwkt_queue;
45 struct lwkt_token;
46 struct lwkt_tokref;
47 struct lwkt_ipiq;
48 struct lwkt_cpu_msg;
49 struct lwkt_cpu_port;
50 struct lwkt_cpusync;
51 union sysunion;
52 
53 typedef struct lwkt_queue	*lwkt_queue_t;
54 typedef struct lwkt_token	*lwkt_token_t;
55 typedef struct lwkt_tokref	*lwkt_tokref_t;
56 typedef struct lwkt_cpu_msg	*lwkt_cpu_msg_t;
57 typedef struct lwkt_cpu_port	*lwkt_cpu_port_t;
58 typedef struct lwkt_ipiq	*lwkt_ipiq_t;
59 typedef struct lwkt_cpusync	*lwkt_cpusync_t;
60 typedef struct thread 		*thread_t;
61 
62 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
63 
64 /*
65  * Differentiation between kernel threads and user threads.  Userland
66  * programs which want to access to kernel structures have to define
67  * _KERNEL_STRUCTURES.  This is a kinda safety valve to prevent badly
68  * written user programs from getting an LWKT thread that is neither the
69  * kernel nor the user version.
70  */
71 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
72 #ifndef _MACHINE_THREAD_H_
73 #include <machine/thread.h>		/* md_thread */
74 #endif
75 #ifndef _MACHINE_FRAME_H_
76 #include <machine/frame.h>
77 #endif
78 #else
79 struct intrframe;
80 #endif
81 
82 /*
83  * Tokens are used to serialize access to information.  They are 'soft'
84  * serialization entities that only stay in effect while a thread is
85  * running.  If the thread blocks, other threads can run holding the same
86  * token(s).  The tokens are reacquired when the original thread resumes.
87  *
88  * A thread can depend on its serialization remaining intact through a
89  * preemption.  An interrupt which attempts to use the same token as the
90  * thread being preempted will reschedule itself for non-preemptive
91  * operation, so the new token code is capable of interlocking against
92  * interrupts as well as other cpus.  This means that your token can only
93  * be (temporarily) lost if you *explicitly* block.
94  *
95  * Tokens are managed through a helper reference structure, lwkt_tokref.  Each
96  * thread has a stack of tokref's to keep track of acquired tokens.  Multiple
97  * tokref's may reference the same token.
98  *
99  * Tokens can be held shared or exclusive.   An exclusive holder is able
100  * to set the TOK_EXCLUSIVE bit in t_count as long as no bit in the count
101  * mask is set.  If unable to accomplish this TOK_EXCLREQ can be set instead
102  * which prevents any new shared acquisitions while the exclusive requestor
103  * spins in the scheduler.  A shared holder can bump t_count by the increment
104  * value as long as neither TOK_EXCLUSIVE or TOK_EXCLREQ is set, else spin
105  * in the scheduler.
106  *
107  * Multiple exclusive tokens are handled by treating the additional tokens
108  * as a special case of the shared token, incrementing the count value.  This
109  * reduces the complexity of the token release code.
110  */
111 
112 typedef struct lwkt_token {
113     long		t_count;	/* Shared/exclreq/exclusive access */
114     struct lwkt_tokref	*t_ref;		/* Exclusive ref */
115     long		t_collisions;	/* Collision counter */
116     const char		*t_desc;	/* Descriptive name */
117 } lwkt_token;
118 
119 #define TOK_EXCLUSIVE	0x00000001	/* Exclusive lock held */
120 #define TOK_EXCLREQ	0x00000002	/* Exclusive request pending */
121 #define TOK_INCR	4		/* Shared count increment */
122 #define TOK_COUNTMASK	(~(long)(TOK_EXCLUSIVE|TOK_EXCLREQ))
123 
124 /*
125  * Static initialization for a lwkt_token.
126  */
127 #define LWKT_TOKEN_INITIALIZER(name)	\
128 {					\
129 	.t_count = 0,			\
130 	.t_ref = NULL,			\
131 	.t_collisions = 0,		\
132 	.t_desc = #name			\
133 }
134 
135 /*
136  * Assert that a particular token is held
137  */
138 #define LWKT_TOKEN_HELD_ANY(tok)	_lwkt_token_held_any(tok, curthread)
139 #define LWKT_TOKEN_HELD_EXCL(tok)	_lwkt_token_held_excl(tok, curthread)
140 
141 #define ASSERT_LWKT_TOKEN_HELD(tok)		\
142 	KKASSERT(LWKT_TOKEN_HELD_ANY(tok))
143 
144 #define ASSERT_LWKT_TOKEN_HELD_EXCL(tok)	\
145 	KKASSERT(LWKT_TOKEN_HELD_EXCL(tok))
146 
147 #define ASSERT_NO_TOKENS_HELD(td)	\
148 	KKASSERT((td)->td_toks_stop == &td->td_toks_array[0])
149 
150 /*
151  * Assert that a particular token is held and we are in a hard
152  * code execution section (interrupt, ipi, or hard code section).
153  * Hard code sections are not allowed to block or potentially block.
154  * e.g. lwkt_gettoken() would only be ok if the token were already
155  * held.
156  */
157 #define ASSERT_LWKT_TOKEN_HARD(tok)					\
158 	do {								\
159 		globaldata_t zgd __debugvar = mycpu;			\
160 		KKASSERT((tok)->t_ref &&				\
161 			 (tok)->t_ref->tr_owner == zgd->gd_curthread &&	\
162 			 zgd->gd_intr_nesting_level > 0);		\
163 	} while(0)
164 
165 /*
166  * Assert that a particular token is held and we are in a normal
167  * critical section.  Critical sections will not be preempted but
168  * can explicitly block (tsleep, lwkt_gettoken, etc).
169  */
170 #define ASSERT_LWKT_TOKEN_CRIT(tok)					\
171 	do {								\
172 		globaldata_t zgd __debugvar = mycpu;			\
173 		KKASSERT((tok)->t_ref &&				\
174 			 (tok)->t_ref->tr_owner == zgd->gd_curthread &&	\
175 			 zgd->gd_curthread->td_critcount > 0);		\
176 	} while(0)
177 
178 struct lwkt_tokref {
179     lwkt_token_t	tr_tok;		/* token in question */
180     long		tr_count;	/* TOK_EXCLUSIVE|TOK_EXCLREQ or 0 */
181     struct thread	*tr_owner;	/* me */
182 };
183 
184 #define MAXCPUFIFO      32	/* power of 2 */
185 #define MAXCPUFIFO_MASK	(MAXCPUFIFO - 1)
186 #define LWKT_MAXTOKENS	32	/* max tokens beneficially held by thread */
187 
188 /*
189  * Always cast to ipifunc_t when registering an ipi.  The actual ipi function
190  * is called with both the data and an interrupt frame, but the ipi function
191  * that is registered might only declare a data argument.
192  */
193 typedef void (*ipifunc1_t)(void *arg);
194 typedef void (*ipifunc2_t)(void *arg, int arg2);
195 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame);
196 
197 struct lwkt_ipiq {
198     int		ip_rindex;      /* only written by target cpu */
199     int		ip_xindex;      /* written by target, indicates completion */
200     int		ip_windex;      /* only written by source cpu */
201     struct {
202 	ipifunc3_t	func;
203 	void		*arg1;
204 	int		arg2;
205 	char		filler[32 - sizeof(int) - sizeof(void *) * 2];
206     } ip_info[MAXCPUFIFO];
207 };
208 
209 /*
210  * CPU Synchronization structure.  See lwkt_cpusync_start() and
211  * lwkt_cpusync_finish() for more information.
212  */
213 typedef void (*cpusync_func_t)(void *arg);
214 
215 struct lwkt_cpusync {
216     cpumask_t	cs_mask;		/* cpus running the sync */
217     cpumask_t	cs_mack;		/* mask acknowledge */
218     cpusync_func_t cs_func;		/* function to execute */
219     void	*cs_data;		/* function data */
220 };
221 
222 /*
223  * The standard message and queue structure used for communications between
224  * cpus.  Messages are typically queued via a machine-specific non-linked
225  * FIFO matrix allowing any cpu to send a message to any other cpu without
226  * blocking.
227  */
228 typedef struct lwkt_cpu_msg {
229     void	(*cm_func)(lwkt_cpu_msg_t msg);	/* primary dispatch function */
230     int		cm_code;		/* request code if applicable */
231     int		cm_cpu;			/* reply to cpu */
232     thread_t	cm_originator;		/* originating thread for wakeup */
233 } lwkt_cpu_msg;
234 
235 /*
236  * Thread structure.  Note that ownership of a thread structure is special
237  * cased and there is no 'token'.  A thread is always owned by the cpu
238  * represented by td_gd, any manipulation of the thread by some other cpu
239  * must be done through cpu_*msg() functions.  e.g. you could request
240  * ownership of a thread that way, or hand a thread off to another cpu.
241  *
242  * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall,
243  *	 trap, and AST/signal transitions to provide a stable ucred for
244  *	 (primarily) system calls.  This field will be NULL for pure kernel
245  *	 threads.
246  */
247 struct md_intr_info;
248 
249 struct thread {
250     TAILQ_ENTRY(thread) td_threadq;
251     TAILQ_ENTRY(thread) td_allq;
252     TAILQ_ENTRY(thread) td_sleepq;
253     lwkt_port	td_msgport;	/* built-in message port for replies */
254     struct lwp	*td_lwp;	/* (optional) associated lwp */
255     struct proc	*td_proc;	/* (optional) associated process */
256     struct pcb	*td_pcb;	/* points to pcb and top of kstack */
257     struct globaldata *td_gd;	/* associated with this cpu */
258     const char	*td_wmesg;	/* string name for blockage */
259     const volatile void	*td_wchan;	/* waiting on channel */
260     int		td_pri;		/* 0-31, 31=highest priority (note 1) */
261     int		td_critcount;	/* critical section priority */
262     u_int	td_flags;	/* TDF flags */
263     int		td_wdomain;	/* domain for wchan address (typ 0) */
264     void	(*td_preemptable)(struct thread *td, int critcount);
265     void	(*td_release)(struct thread *td);
266     char	*td_kstack;	/* kernel stack */
267     int		td_kstack_size;	/* size of kernel stack */
268     char	*td_sp;		/* kernel stack pointer for LWKT restore */
269     thread_t	(*td_switch)(struct thread *ntd);
270     __uint64_t	td_uticks;	/* Statclock hits in user mode (uS) */
271     __uint64_t	td_sticks;      /* Statclock hits in system mode (uS) */
272     __uint64_t	td_iticks;	/* Statclock hits processing intr (uS) */
273     int		td_locks;	/* lockmgr lock debugging */
274     void	*td_dsched_priv1;	/* priv data for I/O schedulers */
275     int		td_refs;	/* hold position in gd_tdallq / hold free */
276     int		td_nest_count;	/* prevent splz nesting */
277     int		td_contended;	/* token contention count */
278     u_int	td_mpflags;	/* flags can be set by foreign cpus */
279     int		td_cscount;	/* cpu synchronization master */
280     int		td_wakefromcpu;	/* who woke me up? */
281     int		td_upri;	/* user priority (sub-priority under td_pri) */
282     int		td_type;	/* thread type, TD_TYPE_ */
283     int		td_unused02[1];	/* for future fields */
284     int		td_unused03[4];	/* for future fields */
285     struct iosched_data td_iosdata;	/* Dynamic I/O scheduling data */
286     struct timeval td_start;	/* start time for a thread/process */
287     char	td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
288     struct thread *td_preempted; /* we preempted this thread */
289     struct ucred *td_ucred;		/* synchronized from p_ucred */
290     void	 *td_vmm;	/* vmm private data */
291     lwkt_tokref_t td_toks_have;		/* tokens we own */
292     lwkt_tokref_t td_toks_stop;		/* tokens we want */
293     struct lwkt_tokref td_toks_array[LWKT_MAXTOKENS];
294     int		td_fairq_load;		/* fairq */
295     int		td_fairq_count;		/* fairq */
296     struct globaldata *td_migrate_gd;	/* target gd for thread migration */
297 #ifdef DEBUG_CRIT_SECTIONS
298 #define CRIT_DEBUG_ARRAY_SIZE   32
299 #define CRIT_DEBUG_ARRAY_MASK   (CRIT_DEBUG_ARRAY_SIZE - 1)
300     const char	*td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE];
301     int		td_crit_debug_index;
302     int		td_in_crit_report;
303 #endif
304     struct md_thread td_mach;
305 #ifdef DEBUG_LOCKS
306 #define SPINLOCK_DEBUG_ARRAY_SIZE	32
307    int 	td_spinlock_stack_id[SPINLOCK_DEBUG_ARRAY_SIZE];
308    struct spinlock *td_spinlock_stack[SPINLOCK_DEBUG_ARRAY_SIZE];
309    void 	*td_spinlock_caller_pc[SPINLOCK_DEBUG_ARRAY_SIZE];
310 
311     /*
312      * Track lockmgr locks held; lk->lk_filename:lk->lk_lineno is the holder
313      */
314 #define LOCKMGR_DEBUG_ARRAY_SIZE	8
315     int		td_lockmgr_stack_id[LOCKMGR_DEBUG_ARRAY_SIZE];
316     struct lock	*td_lockmgr_stack[LOCKMGR_DEBUG_ARRAY_SIZE];
317 #endif
318 };
319 
320 #define td_toks_base		td_toks_array[0]
321 #define td_toks_end		td_toks_array[LWKT_MAXTOKENS]
322 
323 #define TD_TOKS_HELD(td)	((td)->td_toks_stop != &(td)->td_toks_base)
324 #define TD_TOKS_NOT_HELD(td)	((td)->td_toks_stop == &(td)->td_toks_base)
325 
326 /*
327  * Thread flags.  Note that TDF_RUNNING is cleared on the old thread after
328  * we switch to the new one, which is necessary because LWKTs don't need
329  * to hold the BGL.  This flag is used by the exit code and the managed
330  * thread migration code.  Note in addition that preemption will cause
331  * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
332  * must also check TDF_PREEMPT_LOCK.
333  *
334  * LWKT threads stay on their (per-cpu) run queue while running, not to
335  * be confused with user processes which are removed from the user scheduling
336  * run queue while actually running.
337  *
338  * td_threadq can represent the thread on one of three queues... the LWKT
339  * run queue, a tsleep queue, or an lwkt blocking queue.  The LWKT subsystem
340  * does not allow a thread to be scheduled if it already resides on some
341  * queue.
342  */
343 #define TDF_RUNNING		0x00000001	/* thread still active */
344 #define TDF_RUNQ		0x00000002	/* on an LWKT run queue */
345 #define TDF_PREEMPT_LOCK	0x00000004	/* I have been preempted */
346 #define TDF_PREEMPT_DONE	0x00000008	/* ac preemption complete */
347 #define TDF_NOSTART		0x00000010	/* do not schedule on create */
348 #define TDF_MIGRATING		0x00000020	/* thread is being migrated */
349 #define TDF_SINTR		0x00000040	/* interruptability for 'ps' */
350 #define TDF_TSLEEPQ		0x00000080	/* on a tsleep wait queue */
351 
352 #define TDF_SYSTHREAD		0x00000100	/* reserve memory may be used */
353 #define TDF_ALLOCATED_THREAD	0x00000200	/* objcache allocated thread */
354 #define TDF_ALLOCATED_STACK	0x00000400	/* objcache allocated stack */
355 #define TDF_VERBOSE		0x00000800	/* verbose on exit */
356 #define TDF_DEADLKTREAT		0x00001000	/* special lockmgr treatment */
357 #define TDF_MARKER		0x00002000	/* tdallq list scan marker */
358 #define TDF_TIMEOUT_RUNNING	0x00004000	/* tsleep timeout race */
359 #define TDF_TIMEOUT		0x00008000	/* tsleep timeout */
360 #define TDF_INTTHREAD		0x00010000	/* interrupt thread */
361 #define TDF_TSLEEP_DESCHEDULED	0x00020000	/* tsleep core deschedule */
362 #define TDF_BLOCKED		0x00040000	/* Thread is blocked */
363 #define TDF_PANICWARN		0x00080000	/* panic warning in switch */
364 #define TDF_BLOCKQ		0x00100000	/* on block queue */
365 #define TDF_FORCE_SPINPORT	0x00200000
366 #define TDF_EXITING		0x00400000	/* thread exiting */
367 #define TDF_USINGFP		0x00800000	/* thread using fp coproc */
368 #define TDF_KERNELFP		0x01000000	/* kernel using fp coproc */
369 #define TDF_DELAYED_WAKEUP	0x02000000
370 #define TDF_FIXEDCPU		0x04000000	/* running cpu is fixed */
371 #define TDF_USERMODE		0x08000000	/* in or entering user mode */
372 #define TDF_NOFAULT		0x10000000	/* force onfault on fault */
373 
374 #define TDF_MP_STOPREQ		0x00000001	/* suspend_kproc */
375 #define TDF_MP_WAKEREQ		0x00000002	/* resume_kproc */
376 #define TDF_MP_EXITWAIT		0x00000004	/* reaper, see lwp_wait() */
377 #define TDF_MP_EXITSIG		0x00000008	/* reaper, see lwp_wait() */
378 #define TDF_MP_BATCH_DEMARC	0x00000010	/* batch mode handling */
379 #define TDF_MP_DIDYIELD		0x00000020	/* effects scheduling */
380 
381 #define TD_TYPE_GENERIC		0		/* generic thread */
382 #define TD_TYPE_CRYPTO		1		/* crypto thread */
383 #define TD_TYPE_NETISR		2		/* netisr thread */
384 
385 /*
386  * Thread priorities.  Typically only one thread from any given
387  * user process scheduling queue is on the LWKT run queue at a time.
388  * Remember that there is one LWKT run queue per cpu.
389  *
390  * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
391  * causes interrupts to be masked as they occur.  When this occurs a
392  * rollup flag will be set in mycpu->gd_reqflags.
393  */
394 #define TDPRI_IDLE_THREAD	0	/* the idle thread */
395 #define TDPRI_IDLE_WORK		1	/* idle work (page zero, etc) */
396 #define TDPRI_USER_SCHEDULER	2	/* user scheduler helper */
397 #define TDPRI_USER_IDLE		4	/* user scheduler idle */
398 #define TDPRI_USER_NORM		6	/* user scheduler normal */
399 #define TDPRI_USER_REAL		8	/* user scheduler real time */
400 #define TDPRI_KERN_LPSCHED	9	/* scheduler helper for userland sch */
401 #define TDPRI_KERN_USER		10	/* kernel / block in syscall */
402 #define TDPRI_KERN_DAEMON	12	/* kernel daemon (pageout, etc) */
403 #define TDPRI_SOFT_NORM		14	/* kernel / normal */
404 #define TDPRI_SOFT_TIMER	16	/* kernel / timer */
405 #define TDPRI_EXITING		19	/* exiting thread */
406 #define TDPRI_INT_SUPPORT	20	/* kernel / high priority support */
407 #define TDPRI_INT_LOW		27	/* low priority interrupt */
408 #define TDPRI_INT_MED		28	/* medium priority interrupt */
409 #define TDPRI_INT_HIGH		29	/* high priority interrupt */
410 #define TDPRI_MAX		31
411 
412 #define LWKT_THREAD_STACK	(UPAGES * PAGE_SIZE)
413 
414 #define IN_CRITICAL_SECT(td)	((td)->td_critcount)
415 
416 #ifdef _KERNEL
417 
418 /*
419  * Global tokens
420  */
421 extern struct lwkt_token mp_token;
422 extern struct lwkt_token pmap_token;
423 extern struct lwkt_token dev_token;
424 extern struct lwkt_token vm_token;
425 extern struct lwkt_token vmspace_token;
426 extern struct lwkt_token kvm_token;
427 extern struct lwkt_token sigio_token;
428 extern struct lwkt_token tty_token;
429 extern struct lwkt_token vnode_token;
430 extern struct lwkt_token ifnet_token;
431 
432 /*
433  * Procedures
434  */
435 extern void lwkt_init(void);
436 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int);
437 extern void lwkt_init_thread(struct thread *, void *, int, int,
438 			     struct globaldata *);
439 extern void lwkt_set_interrupt_support_thread(void);
440 extern void lwkt_set_comm(thread_t, const char *, ...) __printflike(2, 3);
441 extern void lwkt_free_thread(struct thread *);
442 extern void lwkt_gdinit(struct globaldata *);
443 extern void lwkt_switch(void);
444 extern void lwkt_switch_return(struct thread *);
445 extern void lwkt_preempt(thread_t, int);
446 extern void lwkt_schedule(thread_t);
447 extern void lwkt_schedule_noresched(thread_t);
448 extern void lwkt_schedule_self(thread_t);
449 extern void lwkt_deschedule(thread_t);
450 extern void lwkt_deschedule_self(thread_t);
451 extern void lwkt_yield(void);
452 extern void lwkt_yield_quick(void);
453 extern void lwkt_user_yield(void);
454 extern void lwkt_hold(thread_t);
455 extern void lwkt_rele(thread_t);
456 extern void lwkt_passive_release(thread_t);
457 extern void lwkt_maybe_splz(thread_t);
458 
459 extern void lwkt_gettoken(lwkt_token_t);
460 extern void lwkt_gettoken_shared(lwkt_token_t);
461 extern void lwkt_gettoken_hard(lwkt_token_t);
462 extern int  lwkt_trytoken(lwkt_token_t);
463 extern void lwkt_reltoken(lwkt_token_t);
464 extern void lwkt_reltoken_hard(lwkt_token_t);
465 extern int  lwkt_cnttoken(lwkt_token_t, thread_t);
466 extern int  lwkt_getalltokens(thread_t, int);
467 extern void lwkt_relalltokens(thread_t);
468 extern void lwkt_token_init(lwkt_token_t, const char *);
469 extern void lwkt_token_uninit(lwkt_token_t);
470 
471 extern void lwkt_token_pool_init(void);
472 extern lwkt_token_t lwkt_token_pool_lookup(void *);
473 extern lwkt_token_t lwkt_getpooltoken(void *);
474 extern void lwkt_relpooltoken(void *);
475 
476 extern void lwkt_token_swap(void);
477 
478 extern void lwkt_setpri(thread_t, int);
479 extern void lwkt_setpri_initial(thread_t, int);
480 extern void lwkt_setpri_self(int);
481 extern void lwkt_schedulerclock(thread_t td);
482 extern void lwkt_setcpu_self(struct globaldata *);
483 extern void lwkt_migratecpu(int);
484 
485 extern void lwkt_giveaway(struct thread *);
486 extern void lwkt_acquire(struct thread *);
487 extern int  lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int);
488 extern int  lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t,
489 				    void *, int);
490 extern int  lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t,
491 				   void *, int);
492 extern int  lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int);
493 extern int  lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int);
494 extern void lwkt_wait_ipiq(struct globaldata *, int);
495 extern int  lwkt_seq_ipiq(struct globaldata *);
496 extern void lwkt_process_ipiq(void);
497 extern void lwkt_process_ipiq_frame(struct intrframe *);
498 extern void lwkt_smp_stopped(void);
499 extern void lwkt_synchronize_ipiqs(const char *);
500 
501 /* lwkt_cpusync_init() - inline function in sys/thread2.h */
502 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *);
503 extern void lwkt_cpusync_interlock(lwkt_cpusync_t);
504 extern void lwkt_cpusync_deinterlock(lwkt_cpusync_t);
505 extern void lwkt_cpusync_quick(lwkt_cpusync_t);
506 
507 extern void crit_panic(void) __dead2;
508 extern struct lwp *lwkt_preempted_proc(void);
509 
510 extern int  lwkt_create (void (*func)(void *), void *, struct thread **,
511 		struct thread *, int, int,
512 		const char *, ...) __printflike(7, 8);
513 extern void lwkt_exit (void) __dead2;
514 extern void lwkt_remove_tdallq (struct thread *);
515 
516 #endif
517 
518 #endif
519 
520