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 * $DragonFly: src/sys/sys/thread.h,v 1.97 2008/09/20 04:31:02 sephe Exp $ 11 */ 12 13 #ifndef _SYS_THREAD_H_ 14 #define _SYS_THREAD_H_ 15 16 #ifndef _SYS_STDINT_H_ 17 #include <sys/stdint.h> /* __int types */ 18 #endif 19 #ifndef _SYS_PARAM_H_ 20 #include <sys/param.h> /* MAXCOMLEN */ 21 #endif 22 #ifndef _SYS_QUEUE_H_ 23 #include <sys/queue.h> /* TAILQ_* macros */ 24 #endif 25 #ifndef _SYS_MSGPORT_H_ 26 #include <sys/msgport.h> /* lwkt_port */ 27 #endif 28 #ifndef _SYS_TIME_H_ 29 #include <sys/time.h> /* struct timeval */ 30 #endif 31 #ifndef _SYS_SPINLOCK_H_ 32 #include <sys/spinlock.h> 33 #endif 34 #ifndef _SYS_IOSCHED_H_ 35 #include <sys/iosched.h> 36 #endif 37 #ifndef _MACHINE_THREAD_H_ 38 #include <machine/thread.h> 39 #endif 40 41 struct globaldata; 42 struct lwp; 43 struct proc; 44 struct thread; 45 struct lwkt_queue; 46 struct lwkt_token; 47 struct lwkt_tokref; 48 struct lwkt_ipiq; 49 struct lwkt_cpu_msg; 50 struct lwkt_cpu_port; 51 struct lwkt_msg; 52 struct lwkt_port; 53 struct lwkt_cpusync; 54 union sysunion; 55 56 typedef struct lwkt_queue *lwkt_queue_t; 57 typedef struct lwkt_token *lwkt_token_t; 58 typedef struct lwkt_tokref *lwkt_tokref_t; 59 typedef struct lwkt_cpu_msg *lwkt_cpu_msg_t; 60 typedef struct lwkt_cpu_port *lwkt_cpu_port_t; 61 typedef struct lwkt_ipiq *lwkt_ipiq_t; 62 typedef struct lwkt_cpusync *lwkt_cpusync_t; 63 typedef struct thread *thread_t; 64 65 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue; 66 67 /* 68 * Differentiation between kernel threads and user threads. Userland 69 * programs which want to access to kernel structures have to define 70 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly 71 * written user programs from getting an LWKT thread that is neither the 72 * kernel nor the user version. 73 */ 74 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 75 #ifndef _MACHINE_THREAD_H_ 76 #include <machine/thread.h> /* md_thread */ 77 #endif 78 #ifndef _MACHINE_FRAME_H_ 79 #include <machine/frame.h> 80 #endif 81 #else 82 struct intrframe; 83 #endif 84 85 /* 86 * Tokens are used to serialize access to information. They are 'soft' 87 * serialization entities that only stay in effect while a thread is 88 * running. If the thread blocks, other threads can run holding the same 89 * token(s). The tokens are reacquired when the original thread resumes. 90 * 91 * A thread can depend on its serialization remaining intact through a 92 * preemption. An interrupt which attempts to use the same token as the 93 * thread being preempted will reschedule itself for non-preemptive 94 * operation, so the new token code is capable of interlocking against 95 * interrupts as well as other cpus. This means that your token can only 96 * be (temporarily) lost if you *explicitly* block. 97 * 98 * Tokens are managed through a helper reference structure, lwkt_tokref, 99 * which is typically declared on the caller's stack. Multiple tokref's 100 * may reference the same token. 101 * 102 * It is possible to detect that your token was temporarily lost via 103 * lwkt_token_is_stale(), which uses the t_lastowner field. This field 104 * does NOT necessarily represent the current owner and can become stale 105 * (not point to a valid structure). It is used solely to detect 106 * whether the token was temporarily lost to another thread. The lost 107 * state is cleared by the function. 108 */ 109 110 typedef struct lwkt_token { 111 #ifdef SMP 112 struct spinlock t_spinlock; /* Controls access */ 113 #else 114 struct spinlock t_unused01; 115 #endif 116 struct thread *t_owner; /* The current owner of the token */ 117 int t_count; /* Per-thread count */ 118 struct thread *t_lastowner; /* Last owner that acquired token */ 119 } lwkt_token; 120 121 #ifdef SMP 122 #define LWKT_TOKEN_INITIALIZER(head) \ 123 { \ 124 .t_spinlock = SPINLOCK_INITIALIZER(head.t_spinlock), \ 125 .t_owner = NULL, \ 126 .t_lastowner = NULL, \ 127 .t_count = 0 \ 128 } 129 #else 130 #define LWKT_TOKEN_INITIALIZER(head) \ 131 { \ 132 .t_owner = NULL, \ 133 .t_lastowner = NULL, \ 134 .t_count = 0 \ 135 } 136 #endif 137 138 #define ASSERT_LWKT_TOKEN_HELD(token) \ 139 KKASSERT((token)->t_owner == curthread) 140 141 typedef struct lwkt_tokref { 142 lwkt_token_t tr_tok; /* token in question */ 143 lwkt_tokref_t tr_next; /* linked list */ 144 int tr_state; /* 0 = don't have, 1 = have */ 145 } lwkt_tokref; 146 147 #define LWKT_TOKREF_INIT(tok) \ 148 { tok, NULL, 0 } 149 #define LWKT_TOKREF_DECLARE(name, tok) \ 150 lwkt_tokref name = LWKT_TOKREF_INIT(tok) 151 152 #define MAXCPUFIFO 16 /* power of 2 */ 153 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1) 154 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */ 155 156 /* 157 * Always cast to ipifunc_t when registering an ipi. The actual ipi function 158 * is called with both the data and an interrupt frame, but the ipi function 159 * that is registered might only declare a data argument. 160 */ 161 typedef void (*ipifunc1_t)(void *arg); 162 typedef void (*ipifunc2_t)(void *arg, int arg2); 163 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame); 164 165 typedef struct lwkt_ipiq { 166 int ip_rindex; /* only written by target cpu */ 167 int ip_xindex; /* written by target, indicates completion */ 168 int ip_windex; /* only written by source cpu */ 169 ipifunc3_t ip_func[MAXCPUFIFO]; 170 void *ip_arg1[MAXCPUFIFO]; 171 int ip_arg2[MAXCPUFIFO]; 172 u_int ip_npoll; /* synchronization to avoid excess IPIs */ 173 } lwkt_ipiq; 174 175 /* 176 * CPU Synchronization structure. See lwkt_cpusync_start() and 177 * lwkt_cpusync_finish() for more information. 178 */ 179 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll); 180 typedef void (*cpusync_func2_t)(void *data); 181 182 struct lwkt_cpusync { 183 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */ 184 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */ 185 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */ 186 void *cs_data; 187 int cs_maxcount; 188 volatile int cs_count; 189 cpumask_t cs_mask; 190 }; 191 192 /* 193 * The standard message and queue structure used for communications between 194 * cpus. Messages are typically queued via a machine-specific non-linked 195 * FIFO matrix allowing any cpu to send a message to any other cpu without 196 * blocking. 197 */ 198 typedef struct lwkt_cpu_msg { 199 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */ 200 int cm_code; /* request code if applicable */ 201 int cm_cpu; /* reply to cpu */ 202 thread_t cm_originator; /* originating thread for wakeup */ 203 } lwkt_cpu_msg; 204 205 /* 206 * Thread structure. Note that ownership of a thread structure is special 207 * cased and there is no 'token'. A thread is always owned by the cpu 208 * represented by td_gd, any manipulation of the thread by some other cpu 209 * must be done through cpu_*msg() functions. e.g. you could request 210 * ownership of a thread that way, or hand a thread off to another cpu. 211 * 212 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section, 213 * but this does not effect how the thread is scheduled by LWKT. 214 */ 215 struct md_intr_info; 216 struct caps_kinfo; 217 218 struct thread { 219 TAILQ_ENTRY(thread) td_threadq; 220 TAILQ_ENTRY(thread) td_allq; 221 TAILQ_ENTRY(thread) td_sleepq; 222 lwkt_port td_msgport; /* built-in message port for replies */ 223 struct lwp *td_lwp; /* (optional) associated lwp */ 224 struct proc *td_proc; /* (optional) associated process */ 225 struct pcb *td_pcb; /* points to pcb and top of kstack */ 226 struct globaldata *td_gd; /* associated with this cpu */ 227 const char *td_wmesg; /* string name for blockage */ 228 void *td_wchan; /* waiting on channel */ 229 int td_pri; /* 0-31, 31=highest priority (note 1) */ 230 int td_flags; /* TDF flags */ 231 int td_wdomain; /* domain for wchan address (typ 0) */ 232 void (*td_preemptable)(struct thread *td, int critpri); 233 void (*td_release)(struct thread *td); 234 char *td_kstack; /* kernel stack */ 235 int td_kstack_size; /* size of kernel stack */ 236 char *td_sp; /* kernel stack pointer for LWKT restore */ 237 void (*td_switch)(struct thread *ntd); 238 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */ 239 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */ 240 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */ 241 int td_locks; /* lockmgr lock debugging */ 242 int td_unused01; 243 int td_refs; /* hold position in gd_tdallq / hold free */ 244 int td_nest_count; /* prevent splz nesting */ 245 #ifdef SMP 246 int td_mpcount; /* MP lock held (count) */ 247 int td_cscount; /* cpu synchronization master */ 248 #else 249 int td_mpcount_unused; /* filler so size matches */ 250 int td_cscount_unused; 251 #endif 252 struct iosched_data td_iosdata; /* Dynamic I/O scheduling data */ 253 struct timeval td_start; /* start time for a thread/process */ 254 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */ 255 struct thread *td_preempted; /* we preempted this thread */ 256 struct caps_kinfo *td_caps; /* list of client and server registrations */ 257 lwkt_tokref_t td_toks; /* tokens beneficially held */ 258 #ifdef DEBUG_CRIT_SECTIONS 259 #define CRIT_DEBUG_ARRAY_SIZE 32 260 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1) 261 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE]; 262 int td_crit_debug_index; 263 int td_in_crit_report; 264 #endif 265 struct md_thread td_mach; 266 }; 267 268 /* 269 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after 270 * we switch to the new one, which is necessary because LWKTs don't need 271 * to hold the BGL. This flag is used by the exit code and the managed 272 * thread migration code. Note in addition that preemption will cause 273 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING 274 * must also check TDF_PREEMPT_LOCK. 275 * 276 * LWKT threads stay on their (per-cpu) run queue while running, not to 277 * be confused with user processes which are removed from the user scheduling 278 * run queue while actually running. 279 * 280 * td_threadq can represent the thread on one of three queues... the LWKT 281 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem 282 * does not allow a thread to be scheduled if it already resides on some 283 * queue. 284 */ 285 #define TDF_RUNNING 0x0001 /* thread still active */ 286 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */ 287 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */ 288 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */ 289 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */ 290 #define TDF_MIGRATING 0x0020 /* thread is being migrated */ 291 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */ 292 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */ 293 294 #define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */ 295 #define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */ 296 #define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */ 297 #define TDF_VERBOSE 0x0800 /* verbose on exit */ 298 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */ 299 #define TDF_STOPREQ 0x2000 /* suspend_kproc */ 300 #define TDF_WAKEREQ 0x4000 /* resume_kproc */ 301 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */ 302 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */ 303 #define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */ 304 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */ 305 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */ 306 #define TDF_BLOCKQ 0x00100000 /* on block queue */ 307 #define TDF_MPSAFE 0x00200000 /* (thread creation) */ 308 #define TDF_EXITING 0x00400000 /* thread exiting */ 309 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */ 310 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */ 311 #define TDF_NETWORK 0x02000000 /* network proto thread */ 312 313 /* 314 * Thread priorities. Typically only one thread from any given 315 * user process scheduling queue is on the LWKT run queue at a time. 316 * Remember that there is one LWKT run queue per cpu. 317 * 318 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which 319 * causes interrupts to be masked as they occur. When this occurs a 320 * rollup flag will be set in mycpu->gd_reqflags. 321 */ 322 #define TDPRI_IDLE_THREAD 0 /* the idle thread */ 323 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */ 324 #define TDPRI_USER_IDLE 4 /* user scheduler idle */ 325 #define TDPRI_USER_NORM 6 /* user scheduler normal */ 326 #define TDPRI_USER_REAL 8 /* user scheduler real time */ 327 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */ 328 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */ 329 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */ 330 #define TDPRI_SOFT_NORM 14 /* kernel / normal */ 331 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */ 332 #define TDPRI_EXITING 19 /* exiting thread */ 333 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */ 334 #define TDPRI_INT_LOW 27 /* low priority interrupt */ 335 #define TDPRI_INT_MED 28 /* medium priority interrupt */ 336 #define TDPRI_INT_HIGH 29 /* high priority interrupt */ 337 #define TDPRI_MAX 31 338 339 #define TDPRI_MASK 31 340 #define TDPRI_CRIT 32 /* high bits of td_pri used for crit */ 341 342 #ifdef _KERNEL 343 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE) 344 #endif 345 346 #define CACHE_NTHREADS 6 347 348 #define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT) 349 350 extern void lwkt_init(void); 351 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int); 352 extern void lwkt_init_thread(struct thread *, void *, int, int, 353 struct globaldata *); 354 extern void lwkt_set_comm(thread_t, const char *, ...); 355 extern void lwkt_wait_free(struct thread *); 356 extern void lwkt_free_thread(struct thread *); 357 extern void lwkt_gdinit(struct globaldata *); 358 extern void lwkt_switch(void); 359 extern void lwkt_preempt(thread_t, int); 360 extern void lwkt_schedule(thread_t); 361 extern void lwkt_schedule_noresched(thread_t); 362 extern void lwkt_schedule_self(thread_t); 363 extern void lwkt_deschedule(thread_t); 364 extern void lwkt_deschedule_self(thread_t); 365 extern void lwkt_yield(void); 366 extern void lwkt_user_yield(void); 367 extern void lwkt_token_wait(void); 368 extern void lwkt_hold(thread_t); 369 extern void lwkt_rele(thread_t); 370 extern void lwkt_passive_release(thread_t); 371 372 extern void lwkt_gettoken(lwkt_tokref_t, lwkt_token_t); 373 extern int lwkt_trytoken(lwkt_tokref_t, lwkt_token_t); 374 extern void lwkt_gettokref(lwkt_tokref_t); 375 extern int lwkt_trytokref(lwkt_tokref_t); 376 extern void lwkt_reltoken(lwkt_tokref_t); 377 extern int lwkt_getalltokens(thread_t); 378 extern void lwkt_relalltokens(thread_t); 379 extern void lwkt_drain_token_requests(void); 380 extern void lwkt_token_init(lwkt_token_t); 381 extern void lwkt_token_uninit(lwkt_token_t); 382 extern int lwkt_token_is_stale(lwkt_tokref_t); 383 384 extern void lwkt_token_pool_init(void); 385 extern lwkt_token_t lwkt_token_pool_get(void *); 386 387 extern void lwkt_setpri(thread_t, int); 388 extern void lwkt_setpri_initial(thread_t, int); 389 extern void lwkt_setpri_self(int); 390 extern int lwkt_check_resched(thread_t); 391 extern void lwkt_setcpu_self(struct globaldata *); 392 extern void lwkt_migratecpu(int); 393 394 #ifdef SMP 395 396 extern void lwkt_giveaway(struct thread *); 397 extern void lwkt_acquire(struct thread *); 398 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int); 399 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t, 400 void *, int); 401 extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t, 402 void *, int); 403 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int); 404 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int); 405 extern void lwkt_wait_ipiq(struct globaldata *, int); 406 extern int lwkt_seq_ipiq(struct globaldata *); 407 extern void lwkt_process_ipiq(void); 408 #ifdef _KERNEL 409 extern void lwkt_process_ipiq_frame(struct intrframe *); 410 #endif 411 extern void lwkt_smp_stopped(void); 412 extern void lwkt_synchronize_ipiqs(const char *); 413 414 #endif /* SMP */ 415 416 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *); 417 extern void lwkt_cpusync_fastdata(cpumask_t, cpusync_func2_t, void *); 418 extern void lwkt_cpusync_start(cpumask_t, lwkt_cpusync_t); 419 extern void lwkt_cpusync_add(cpumask_t, lwkt_cpusync_t); 420 extern void lwkt_cpusync_finish(lwkt_cpusync_t); 421 422 extern void crit_panic(void); 423 extern struct lwp *lwkt_preempted_proc(void); 424 425 extern int lwkt_create (void (*func)(void *), void *, struct thread **, 426 struct thread *, int, int, const char *, ...); 427 extern void lwkt_exit (void) __dead2; 428 extern void lwkt_remove_tdallq (struct thread *); 429 extern void lwkt_mp_lock_contested(void); 430 extern void lwkt_mp_lock_uncontested(void); 431 432 #endif 433 434