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 _MACHINE_THREAD_H_ 35 #include <machine/thread.h> 36 #endif 37 38 struct globaldata; 39 struct lwp; 40 struct proc; 41 struct thread; 42 struct lwkt_queue; 43 struct lwkt_token; 44 struct lwkt_tokref; 45 struct lwkt_ipiq; 46 struct lwkt_cpu_msg; 47 struct lwkt_cpu_port; 48 struct lwkt_msg; 49 struct lwkt_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, 96 * which is typically declared on the caller's stack. Multiple tokref's 97 * may reference the same token. 98 * 99 * It is possible to detect that your token was temporarily lost via 100 * lwkt_token_is_stale(), which uses the t_lastowner field. This field 101 * does NOT necessarily represent the current owner and can become stale 102 * (not point to a valid structure). It is used solely to detect 103 * whether the token was temporarily lost to another thread. The lost 104 * state is cleared by the function. 105 */ 106 107 typedef struct lwkt_token { 108 #ifdef SMP 109 struct spinlock t_spinlock; /* Controls access */ 110 #else 111 struct spinlock t_unused01; 112 #endif 113 struct thread *t_owner; /* The current owner of the token */ 114 int t_count; /* Per-thread count */ 115 struct thread *t_lastowner; /* Last owner that acquired token */ 116 } lwkt_token; 117 118 #ifdef SMP 119 #define LWKT_TOKEN_INITIALIZER(head) \ 120 { \ 121 .t_spinlock = SPINLOCK_INITIALIZER(head.t_spinlock), \ 122 .t_owner = NULL, \ 123 .t_lastowner = NULL, \ 124 .t_count = 0 \ 125 } 126 #else 127 #define LWKT_TOKEN_INITIALIZER(head) \ 128 { \ 129 .t_owner = NULL, \ 130 .t_lastowner = NULL, \ 131 .t_count = 0 \ 132 } 133 #endif 134 135 typedef struct lwkt_tokref { 136 lwkt_token_t tr_tok; /* token in question */ 137 lwkt_tokref_t tr_next; /* linked list */ 138 int tr_state; /* 0 = don't have, 1 = have */ 139 } lwkt_tokref; 140 141 #define LWKT_TOKREF_INIT(tok) \ 142 { tok, NULL, 0 } 143 #define LWKT_TOKREF_DECLARE(name, tok) \ 144 lwkt_tokref name = LWKT_TOKREF_INIT(tok) 145 146 #define MAXCPUFIFO 16 /* power of 2 */ 147 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1) 148 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */ 149 150 /* 151 * Always cast to ipifunc_t when registering an ipi. The actual ipi function 152 * is called with both the data and an interrupt frame, but the ipi function 153 * that is registered might only declare a data argument. 154 */ 155 typedef void (*ipifunc1_t)(void *arg); 156 typedef void (*ipifunc2_t)(void *arg, int arg2); 157 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame); 158 159 typedef struct lwkt_ipiq { 160 int ip_rindex; /* only written by target cpu */ 161 int ip_xindex; /* written by target, indicates completion */ 162 int ip_windex; /* only written by source cpu */ 163 ipifunc3_t ip_func[MAXCPUFIFO]; 164 void *ip_arg1[MAXCPUFIFO]; 165 int ip_arg2[MAXCPUFIFO]; 166 u_int ip_npoll; /* synchronization to avoid excess IPIs */ 167 } lwkt_ipiq; 168 169 /* 170 * CPU Synchronization structure. See lwkt_cpusync_start() and 171 * lwkt_cpusync_finish() for more information. 172 */ 173 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll); 174 typedef void (*cpusync_func2_t)(void *data); 175 176 struct lwkt_cpusync { 177 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */ 178 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */ 179 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */ 180 void *cs_data; 181 int cs_maxcount; 182 volatile int cs_count; 183 cpumask_t cs_mask; 184 }; 185 186 /* 187 * The standard message and queue structure used for communications between 188 * cpus. Messages are typically queued via a machine-specific non-linked 189 * FIFO matrix allowing any cpu to send a message to any other cpu without 190 * blocking. 191 */ 192 typedef struct lwkt_cpu_msg { 193 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */ 194 int cm_code; /* request code if applicable */ 195 int cm_cpu; /* reply to cpu */ 196 thread_t cm_originator; /* originating thread for wakeup */ 197 } lwkt_cpu_msg; 198 199 /* 200 * Thread structure. Note that ownership of a thread structure is special 201 * cased and there is no 'token'. A thread is always owned by the cpu 202 * represented by td_gd, any manipulation of the thread by some other cpu 203 * must be done through cpu_*msg() functions. e.g. you could request 204 * ownership of a thread that way, or hand a thread off to another cpu. 205 * 206 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section, 207 * but this does not effect how the thread is scheduled by LWKT. 208 */ 209 struct md_intr_info; 210 struct caps_kinfo; 211 212 struct thread { 213 TAILQ_ENTRY(thread) td_threadq; 214 TAILQ_ENTRY(thread) td_allq; 215 lwkt_port td_msgport; /* built-in message port for replies */ 216 struct lwp *td_lwp; /* (optional) associated lwp */ 217 struct proc *td_proc; /* (optional) associated process */ 218 struct pcb *td_pcb; /* points to pcb and top of kstack */ 219 struct globaldata *td_gd; /* associated with this cpu */ 220 const char *td_wmesg; /* string name for blockage */ 221 void *td_wchan; /* waiting on channel */ 222 int td_pri; /* 0-31, 31=highest priority (note 1) */ 223 int td_flags; /* TDF flags */ 224 int td_wdomain; /* domain for wchan address (typ 0) */ 225 void (*td_preemptable)(struct thread *td, int critpri); 226 void (*td_release)(struct thread *td); 227 char *td_kstack; /* kernel stack */ 228 int td_kstack_size; /* size of kernel stack */ 229 char *td_sp; /* kernel stack pointer for LWKT restore */ 230 void (*td_switch)(struct thread *ntd); 231 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */ 232 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */ 233 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */ 234 int td_locks; /* lockmgr lock debugging */ 235 int td_unused01; 236 int td_refs; /* hold position in gd_tdallq / hold free */ 237 int td_nest_count; /* prevent splz nesting */ 238 #ifdef SMP 239 int td_mpcount; /* MP lock held (count) */ 240 int td_cscount; /* cpu synchronization master */ 241 #else 242 int td_mpcount_unused; /* filler so size matches */ 243 int td_cscount_unused; 244 #endif 245 struct timeval td_start; /* start time for a thread/process */ 246 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */ 247 struct thread *td_preempted; /* we preempted this thread */ 248 struct caps_kinfo *td_caps; /* list of client and server registrations */ 249 lwkt_tokref_t td_toks; /* tokens beneficially held */ 250 #ifdef DEBUG_CRIT_SECTIONS 251 #define CRIT_DEBUG_ARRAY_SIZE 32 252 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1) 253 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE]; 254 int td_crit_debug_index; 255 int td_in_crit_report; 256 #endif 257 struct md_thread td_mach; 258 }; 259 260 /* 261 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after 262 * we switch to the new one, which is necessary because LWKTs don't need 263 * to hold the BGL. This flag is used by the exit code and the managed 264 * thread migration code. Note in addition that preemption will cause 265 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING 266 * must also check TDF_PREEMPT_LOCK. 267 * 268 * LWKT threads stay on their (per-cpu) run queue while running, not to 269 * be confused with user processes which are removed from the user scheduling 270 * run queue while actually running. 271 * 272 * td_threadq can represent the thread on one of three queues... the LWKT 273 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem 274 * does not allow a thread to be scheduled if it already resides on some 275 * queue. 276 */ 277 #define TDF_RUNNING 0x0001 /* thread still active */ 278 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */ 279 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */ 280 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */ 281 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */ 282 #define TDF_MIGRATING 0x0020 /* thread is being migrated */ 283 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */ 284 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */ 285 286 #define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */ 287 #define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */ 288 #define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */ 289 #define TDF_VERBOSE 0x0800 /* verbose on exit */ 290 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */ 291 #define TDF_STOPREQ 0x2000 /* suspend_kproc */ 292 #define TDF_WAKEREQ 0x4000 /* resume_kproc */ 293 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */ 294 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */ 295 #define TDF_UNUSED20000 0x00020000 296 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */ 297 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */ 298 #define TDF_BLOCKQ 0x00100000 /* on block queue */ 299 #define TDF_MPSAFE 0x00200000 /* (thread creation) */ 300 #define TDF_EXITING 0x00400000 /* thread exiting */ 301 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */ 302 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */ 303 #define TDF_NETWORK 0x02000000 /* network proto thread */ 304 305 /* 306 * Thread priorities. Typically only one thread from any given 307 * user process scheduling queue is on the LWKT run queue at a time. 308 * Remember that there is one LWKT run queue per cpu. 309 * 310 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which 311 * causes interrupts to be masked as they occur. When this occurs a 312 * rollup flag will be set in mycpu->gd_reqflags. 313 */ 314 #define TDPRI_IDLE_THREAD 0 /* the idle thread */ 315 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */ 316 #define TDPRI_USER_IDLE 4 /* user scheduler idle */ 317 #define TDPRI_USER_NORM 6 /* user scheduler normal */ 318 #define TDPRI_USER_REAL 8 /* user scheduler real time */ 319 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */ 320 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */ 321 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */ 322 #define TDPRI_SOFT_NORM 14 /* kernel / normal */ 323 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */ 324 #define TDPRI_EXITING 19 /* exiting thread */ 325 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */ 326 #define TDPRI_INT_LOW 27 /* low priority interrupt */ 327 #define TDPRI_INT_MED 28 /* medium priority interrupt */ 328 #define TDPRI_INT_HIGH 29 /* high priority interrupt */ 329 #define TDPRI_MAX 31 330 331 #define TDPRI_MASK 31 332 #define TDPRI_CRIT 32 /* high bits of td_pri used for crit */ 333 334 #ifdef _KERNEL 335 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE) 336 #endif 337 338 #define CACHE_NTHREADS 6 339 340 #define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT) 341 342 extern void lwkt_init(void); 343 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int); 344 extern void lwkt_init_thread(struct thread *, void *, int, int, 345 struct globaldata *); 346 extern void lwkt_set_comm(thread_t, const char *, ...); 347 extern void lwkt_wait_free(struct thread *); 348 extern void lwkt_free_thread(struct thread *); 349 extern void lwkt_gdinit(struct globaldata *); 350 extern void lwkt_switch(void); 351 extern void lwkt_preempt(thread_t, int); 352 extern void lwkt_schedule(thread_t); 353 extern void lwkt_schedule_noresched(thread_t); 354 extern void lwkt_schedule_self(thread_t); 355 extern void lwkt_deschedule(thread_t); 356 extern void lwkt_deschedule_self(thread_t); 357 extern void lwkt_yield(void); 358 extern void lwkt_yield_quick(void); 359 extern void lwkt_token_wait(void); 360 extern void lwkt_hold(thread_t); 361 extern void lwkt_rele(thread_t); 362 363 extern void lwkt_gettoken(lwkt_tokref_t, lwkt_token_t); 364 extern int lwkt_trytoken(lwkt_tokref_t, lwkt_token_t); 365 extern void lwkt_gettokref(lwkt_tokref_t); 366 extern int lwkt_trytokref(lwkt_tokref_t); 367 extern void lwkt_reltoken(lwkt_tokref_t); 368 extern int lwkt_getalltokens(thread_t); 369 extern void lwkt_relalltokens(thread_t); 370 extern void lwkt_drain_token_requests(void); 371 extern void lwkt_token_init(lwkt_token_t); 372 extern void lwkt_token_uninit(lwkt_token_t); 373 extern int lwkt_token_is_stale(lwkt_tokref_t); 374 375 extern void lwkt_token_pool_init(void); 376 extern lwkt_token_t lwkt_token_pool_get(void *); 377 378 extern void lwkt_setpri(thread_t, int); 379 extern void lwkt_setpri_self(int); 380 extern int lwkt_check_resched(thread_t); 381 extern void lwkt_setcpu_self(struct globaldata *); 382 extern void lwkt_migratecpu(int); 383 384 #ifdef SMP 385 386 extern void lwkt_giveaway(struct thread *); 387 extern void lwkt_acquire(struct thread *); 388 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int); 389 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t, 390 void *, int); 391 extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t, 392 void *, int); 393 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int); 394 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int); 395 extern void lwkt_wait_ipiq(struct globaldata *, int); 396 extern int lwkt_seq_ipiq(struct globaldata *); 397 extern void lwkt_process_ipiq(void); 398 #ifdef _KERNEL 399 extern void lwkt_process_ipiq_frame(struct intrframe *); 400 #endif 401 extern void lwkt_smp_stopped(void); 402 extern void lwkt_synchronize_ipiqs(const char *); 403 404 #endif /* SMP */ 405 406 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *); 407 extern void lwkt_cpusync_fastdata(cpumask_t, cpusync_func2_t, void *); 408 extern void lwkt_cpusync_start(cpumask_t, lwkt_cpusync_t); 409 extern void lwkt_cpusync_add(cpumask_t, lwkt_cpusync_t); 410 extern void lwkt_cpusync_finish(lwkt_cpusync_t); 411 412 extern void crit_panic(void); 413 extern struct lwp *lwkt_preempted_proc(void); 414 415 extern int lwkt_create (void (*func)(void *), void *, struct thread **, 416 struct thread *, int, int, const char *, ...); 417 extern void lwkt_exit (void) __dead2; 418 extern void lwkt_remove_tdallq (struct thread *); 419 extern void lwkt_mp_lock_contested(void); 420 extern void lwkt_mp_lock_uncontested(void); 421 422 #endif 423 424