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 _CPU_FRAME_H_ 73 #include <machine/frame.h> 74 #endif 75 #else 76 struct intrframe; 77 #endif 78 79 /* 80 * Tokens are used to serialize access to information. They are 'soft' 81 * serialization entities that only stay in effect while a thread is 82 * running. If the thread blocks, other threads can run holding the same 83 * token(s). The tokens are reacquired when the original thread resumes. 84 * 85 * A thread can depend on its serialization remaining intact through a 86 * preemption. An interrupt which attempts to use the same token as the 87 * thread being preempted will reschedule itself for non-preemptive 88 * operation, so the new token code is capable of interlocking against 89 * interrupts as well as other cpus. This means that your token can only 90 * be (temporarily) lost if you *explicitly* block. 91 * 92 * Tokens are managed through a helper reference structure, lwkt_tokref. Each 93 * thread has a stack of tokref's to keep track of acquired tokens. Multiple 94 * tokref's may reference the same token. 95 * 96 * Tokens can be held shared or exclusive. An exclusive holder is able 97 * to set the TOK_EXCLUSIVE bit in t_count as long as no bit in the count 98 * mask is set. If unable to accomplish this TOK_EXCLREQ can be set instead 99 * which prevents any new shared acquisitions while the exclusive requestor 100 * spins in the scheduler. A shared holder can bump t_count by the increment 101 * value as long as neither TOK_EXCLUSIVE or TOK_EXCLREQ is set, else spin 102 * in the scheduler. 103 * 104 * Multiple exclusive tokens are handled by treating the additional tokens 105 * as a special case of the shared token, incrementing the count value. This 106 * reduces the complexity of the token release code. 107 */ 108 109 typedef struct lwkt_token { 110 long t_count; /* Shared/exclreq/exclusive access */ 111 struct lwkt_tokref *t_ref; /* Exclusive ref */ 112 long t_collisions; /* Collision counter */ 113 const char *t_desc; /* Descriptive name */ 114 } lwkt_token; 115 116 #define TOK_EXCLUSIVE 0x00000001 /* Exclusive lock held */ 117 #define TOK_EXCLREQ 0x00000002 /* Exclusive request pending */ 118 #define TOK_INCR 4 /* Shared count increment */ 119 #define TOK_COUNTMASK (~(long)(TOK_EXCLUSIVE|TOK_EXCLREQ)) 120 121 /* 122 * Static initialization for a lwkt_token. 123 */ 124 #define LWKT_TOKEN_INITIALIZER(name) \ 125 { \ 126 .t_count = 0, \ 127 .t_ref = NULL, \ 128 .t_collisions = 0, \ 129 .t_desc = #name \ 130 } 131 132 /* 133 * Assert that a particular token is held 134 */ 135 #define LWKT_TOKEN_HELD_ANY(tok) _lwkt_token_held_any(tok, curthread) 136 #define LWKT_TOKEN_HELD_EXCL(tok) _lwkt_token_held_excl(tok, curthread) 137 138 #define ASSERT_LWKT_TOKEN_HELD(tok) \ 139 KKASSERT(LWKT_TOKEN_HELD_ANY(tok)) 140 141 #define ASSERT_LWKT_TOKEN_HELD_EXCL(tok) \ 142 KKASSERT(LWKT_TOKEN_HELD_EXCL(tok)) 143 144 #define ASSERT_NO_TOKENS_HELD(td) \ 145 KKASSERT((td)->td_toks_stop == &td->td_toks_array[0]) 146 147 struct lwkt_tokref { 148 lwkt_token_t tr_tok; /* token in question */ 149 long tr_count; /* TOK_EXCLUSIVE|TOK_EXCLREQ or 0 */ 150 struct thread *tr_owner; /* me */ 151 }; 152 153 #define MAXCPUFIFO 32 /* power of 2 */ 154 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1) 155 #define LWKT_MAXTOKENS 32 /* max tokens beneficially held by thread */ 156 157 /* 158 * Always cast to ipifunc_t when registering an ipi. The actual ipi function 159 * is called with both the data and an interrupt frame, but the ipi function 160 * that is registered might only declare a data argument. 161 */ 162 typedef void (*ipifunc1_t)(void *arg); 163 typedef void (*ipifunc2_t)(void *arg, int arg2); 164 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame); 165 166 struct lwkt_ipiq { 167 int ip_rindex; /* only written by target cpu */ 168 int ip_xindex; /* written by target, indicates completion */ 169 int ip_windex; /* only written by source cpu */ 170 int ip_drain; /* drain source limit */ 171 struct { 172 ipifunc3_t func; 173 void *arg1; 174 int arg2; 175 char filler[32 - sizeof(int) - sizeof(void *) * 2]; 176 } ip_info[MAXCPUFIFO]; 177 }; 178 179 /* 180 * CPU Synchronization structure. See lwkt_cpusync_start() and 181 * lwkt_cpusync_finish() for more information. 182 */ 183 typedef void (*cpusync_func_t)(void *arg); 184 185 struct lwkt_cpusync { 186 cpumask_t cs_mask; /* cpus running the sync */ 187 cpumask_t cs_mack; /* mask acknowledge */ 188 cpusync_func_t cs_func; /* function to execute */ 189 void *cs_data; /* function data */ 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_ucred is synchronized from the p_ucred on user->kernel syscall, 213 * trap, and AST/signal transitions to provide a stable ucred for 214 * (primarily) system calls. This field will be NULL for pure kernel 215 * threads. 216 */ 217 struct md_intr_info; 218 219 struct thread { 220 TAILQ_ENTRY(thread) td_threadq; 221 TAILQ_ENTRY(thread) td_allq; 222 TAILQ_ENTRY(thread) td_sleepq; 223 lwkt_port td_msgport; /* built-in message port for replies */ 224 struct lwp *td_lwp; /* (optional) associated lwp */ 225 struct proc *td_proc; /* (optional) associated process */ 226 struct pcb *td_pcb; /* points to pcb and top of kstack */ 227 struct globaldata *td_gd; /* associated with this cpu */ 228 const char *td_wmesg; /* string name for blockage */ 229 const volatile void *td_wchan; /* waiting on channel */ 230 int td_pri; /* 0-31, 31=highest priority (note 1) */ 231 int td_critcount; /* critical section priority */ 232 u_int td_flags; /* TDF flags */ 233 int td_wdomain; /* domain for wchan address (typ 0) */ 234 void (*td_preemptable)(struct thread *td, int critcount); 235 void (*td_release)(struct thread *td); 236 char *td_kstack; /* kernel stack */ 237 int td_kstack_size; /* size of kernel stack */ 238 char *td_sp; /* kernel stack pointer for LWKT restore */ 239 thread_t (*td_switch)(struct thread *ntd); 240 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */ 241 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */ 242 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */ 243 int td_locks; /* lockmgr lock debugging */ 244 void *td_unused01; /* (future I/O scheduler heuristic) */ 245 int td_refs; /* hold position in gd_tdallq / hold free */ 246 int td_nest_count; /* prevent splz nesting */ 247 u_int td_contended; /* token contention count */ 248 u_int td_mpflags; /* flags can be set by foreign cpus */ 249 int td_cscount; /* cpu synchronization master */ 250 int td_wakefromcpu; /* who woke me up? */ 251 int td_upri; /* user priority (sub-priority under td_pri) */ 252 int td_type; /* thread type, TD_TYPE_ */ 253 int td_tracker; /* for callers to debug lock counts */ 254 int td_unused03[4]; /* for future fields */ 255 struct iosched_data td_iosdata; /* Dynamic I/O scheduling data */ 256 struct timeval td_start; /* start time for a thread/process */ 257 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */ 258 struct thread *td_preempted; /* we preempted this thread */ 259 struct ucred *td_ucred; /* synchronized from p_ucred */ 260 void *td_vmm; /* vmm private data */ 261 lwkt_tokref_t td_toks_have; /* tokens we own */ 262 lwkt_tokref_t td_toks_stop; /* tokens we want */ 263 struct lwkt_tokref td_toks_array[LWKT_MAXTOKENS]; 264 int td_fairq_load; /* fairq */ 265 int td_fairq_count; /* fairq */ 266 struct globaldata *td_migrate_gd; /* target gd for thread migration */ 267 #ifdef DEBUG_CRIT_SECTIONS 268 #define CRIT_DEBUG_ARRAY_SIZE 32 269 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1) 270 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE]; 271 int td_crit_debug_index; 272 int td_in_crit_report; 273 #endif 274 struct md_thread td_mach; 275 #ifdef DEBUG_LOCKS 276 #define SPINLOCK_DEBUG_ARRAY_SIZE 32 277 int td_spinlock_stack_id[SPINLOCK_DEBUG_ARRAY_SIZE]; 278 struct spinlock *td_spinlock_stack[SPINLOCK_DEBUG_ARRAY_SIZE]; 279 void *td_spinlock_caller_pc[SPINLOCK_DEBUG_ARRAY_SIZE]; 280 281 /* 282 * Track lockmgr locks held; lk->lk_filename:lk->lk_lineno is the holder 283 */ 284 #define LOCKMGR_DEBUG_ARRAY_SIZE 8 285 int td_lockmgr_stack_id[LOCKMGR_DEBUG_ARRAY_SIZE]; 286 struct lock *td_lockmgr_stack[LOCKMGR_DEBUG_ARRAY_SIZE]; 287 #endif 288 }; 289 290 #define td_toks_base td_toks_array[0] 291 #define td_toks_end td_toks_array[LWKT_MAXTOKENS] 292 293 #define TD_TOKS_HELD(td) ((td)->td_toks_stop != &(td)->td_toks_base) 294 #define TD_TOKS_NOT_HELD(td) ((td)->td_toks_stop == &(td)->td_toks_base) 295 296 /* 297 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after 298 * we switch to the new one, which is necessary because LWKTs don't need 299 * to hold the BGL. This flag is used by the exit code and the managed 300 * thread migration code. Note in addition that preemption will cause 301 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING 302 * must also check TDF_PREEMPT_LOCK. 303 * 304 * LWKT threads stay on their (per-cpu) run queue while running, not to 305 * be confused with user processes which are removed from the user scheduling 306 * run queue while actually running. 307 * 308 * td_threadq can represent the thread on one of three queues... the LWKT 309 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem 310 * does not allow a thread to be scheduled if it already resides on some 311 * queue. 312 */ 313 #define TDF_RUNNING 0x00000001 /* thread still active */ 314 #define TDF_RUNQ 0x00000002 /* on an LWKT run queue */ 315 #define TDF_PREEMPT_LOCK 0x00000004 /* I have been preempted */ 316 #define TDF_PREEMPT_DONE 0x00000008 /* ac preemption complete */ 317 #define TDF_NOSTART 0x00000010 /* do not schedule on create */ 318 #define TDF_MIGRATING 0x00000020 /* thread is being migrated */ 319 #define TDF_SINTR 0x00000040 /* interruptability for 'ps' */ 320 #define TDF_TSLEEPQ 0x00000080 /* on a tsleep wait queue */ 321 322 #define TDF_SYSTHREAD 0x00000100 /* reserve memory may be used */ 323 #define TDF_ALLOCATED_THREAD 0x00000200 /* objcache allocated thread */ 324 #define TDF_ALLOCATED_STACK 0x00000400 /* objcache allocated stack */ 325 #define TDF_VERBOSE 0x00000800 /* verbose on exit */ 326 #define TDF_DEADLKTREAT 0x00001000 /* special lockmgr treatment */ 327 #define TDF_MARKER 0x00002000 /* tdallq list scan marker */ 328 #define TDF_TIMEOUT_RUNNING 0x00004000 /* tsleep timeout race */ 329 #define TDF_TIMEOUT 0x00008000 /* tsleep timeout */ 330 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */ 331 #define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */ 332 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */ 333 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */ 334 #define TDF_BLOCKQ 0x00100000 /* on block queue */ 335 #define TDF_FORCE_SPINPORT 0x00200000 336 #define TDF_EXITING 0x00400000 /* thread exiting */ 337 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */ 338 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */ 339 #define TDF_DELAYED_WAKEUP 0x02000000 340 #define TDF_FIXEDCPU 0x04000000 /* running cpu is fixed */ 341 #define TDF_USERMODE 0x08000000 /* in or entering user mode */ 342 #define TDF_NOFAULT 0x10000000 /* force onfault on fault */ 343 344 #define TDF_MP_STOPREQ 0x00000001 /* suspend_kproc */ 345 #define TDF_MP_WAKEREQ 0x00000002 /* resume_kproc */ 346 #define TDF_MP_EXITWAIT 0x00000004 /* reaper, see lwp_wait() */ 347 #define TDF_MP_EXITSIG 0x00000008 /* reaper, see lwp_wait() */ 348 #define TDF_MP_BATCH_DEMARC 0x00000010 /* batch mode handling */ 349 #define TDF_MP_DIDYIELD 0x00000020 /* effects scheduling */ 350 351 #define TD_TYPE_GENERIC 0 /* generic thread */ 352 #define TD_TYPE_CRYPTO 1 /* crypto thread */ 353 #define TD_TYPE_NETISR 2 /* netisr thread */ 354 355 /* 356 * Thread priorities. Typically only one thread from any given 357 * user process scheduling queue is on the LWKT run queue at a time. 358 * Remember that there is one LWKT run queue per cpu. 359 * 360 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which 361 * causes interrupts to be masked as they occur. When this occurs a 362 * rollup flag will be set in mycpu->gd_reqflags. 363 */ 364 #define TDPRI_IDLE_THREAD 0 /* the idle thread */ 365 #define TDPRI_IDLE_WORK 1 /* idle work (page zero, etc) */ 366 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */ 367 #define TDPRI_USER_IDLE 4 /* user scheduler idle */ 368 #define TDPRI_USER_NORM 6 /* user scheduler normal */ 369 #define TDPRI_USER_REAL 8 /* user scheduler real time */ 370 #define TDPRI_KERN_LPSCHED 9 /* (comparison point only) */ 371 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */ 372 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */ 373 #define TDPRI_SOFT_NORM 14 /* kernel / normal */ 374 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */ 375 #define TDPRI_UNUSED19 19 376 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */ 377 #define TDPRI_INT_LOW 27 /* low priority interrupt */ 378 #define TDPRI_INT_MED 28 /* medium priority interrupt */ 379 #define TDPRI_INT_HIGH 29 /* high priority interrupt */ 380 #define TDPRI_MAX 31 381 382 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE) 383 384 #define IN_CRITICAL_SECT(td) ((td)->td_critcount) 385 386 #ifdef _KERNEL 387 388 /* 389 * Global tokens 390 */ 391 extern struct lwkt_token mp_token; 392 extern struct lwkt_token pmap_token; 393 extern struct lwkt_token dev_token; 394 extern struct lwkt_token vm_token; 395 extern struct lwkt_token vmspace_token; 396 extern struct lwkt_token kvm_token; 397 extern struct lwkt_token sigio_token; 398 extern struct lwkt_token tty_token; 399 extern struct lwkt_token vnode_token; 400 extern struct lwkt_token revoke_token; 401 402 /* 403 * Procedures 404 */ 405 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int); 406 extern void lwkt_init_thread(struct thread *, void *, int, int, 407 struct globaldata *); 408 extern void lwkt_set_interrupt_support_thread(void); 409 extern void lwkt_set_comm(thread_t, const char *, ...) __printflike(2, 3); 410 extern void lwkt_free_thread(struct thread *); 411 extern void lwkt_gdinit(struct globaldata *); 412 extern void lwkt_switch(void); 413 extern void lwkt_switch_return(struct thread *); 414 extern void lwkt_preempt(thread_t, int); 415 extern void lwkt_schedule(thread_t); 416 extern void lwkt_schedule_noresched(thread_t); 417 extern void lwkt_schedule_self(thread_t); 418 extern void lwkt_deschedule(thread_t); 419 extern void lwkt_deschedule_self(thread_t); 420 extern void lwkt_yield(void); 421 extern void lwkt_yield_quick(void); 422 extern void lwkt_user_yield(void); 423 extern void lwkt_hold(thread_t); 424 extern void lwkt_rele(thread_t); 425 extern void lwkt_passive_release(thread_t); 426 extern void lwkt_maybe_splz(thread_t); 427 428 extern void lwkt_gettoken(lwkt_token_t); 429 extern void lwkt_gettoken_shared(lwkt_token_t); 430 extern int lwkt_trytoken(lwkt_token_t); 431 extern void lwkt_reltoken(lwkt_token_t); 432 extern int lwkt_cnttoken(lwkt_token_t, thread_t); 433 extern int lwkt_getalltokens(thread_t, int); 434 extern void lwkt_relalltokens(thread_t); 435 extern void lwkt_token_init(lwkt_token_t, const char *); 436 extern void lwkt_token_uninit(lwkt_token_t); 437 438 extern void lwkt_token_pool_init(void); 439 extern lwkt_token_t lwkt_token_pool_lookup(void *); 440 extern lwkt_token_t lwkt_getpooltoken(void *); 441 extern void lwkt_relpooltoken(void *); 442 443 extern void lwkt_token_swap(void); 444 445 extern void lwkt_setpri(thread_t, int); 446 extern void lwkt_setpri_initial(thread_t, int); 447 extern void lwkt_setpri_self(int); 448 extern void lwkt_schedulerclock(thread_t td); 449 extern void lwkt_setcpu_self(struct globaldata *); 450 extern void lwkt_migratecpu(int); 451 452 extern void lwkt_giveaway(struct thread *); 453 extern void lwkt_acquire(struct thread *); 454 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int); 455 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t, 456 void *, int); 457 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int); 458 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int); 459 extern void lwkt_wait_ipiq(struct globaldata *, int); 460 extern void lwkt_process_ipiq(void); 461 extern void lwkt_process_ipiq_frame(struct intrframe *); 462 extern void lwkt_smp_stopped(void); 463 extern void lwkt_synchronize_ipiqs(const char *); 464 465 /* lwkt_cpusync_init() - inline function in sys/thread2.h */ 466 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *); 467 extern void lwkt_cpusync_interlock(lwkt_cpusync_t); 468 extern void lwkt_cpusync_deinterlock(lwkt_cpusync_t); 469 extern void lwkt_cpusync_quick(lwkt_cpusync_t); 470 471 extern void crit_panic(void) __dead2; 472 extern struct lwp *lwkt_preempted_proc(void); 473 474 extern int lwkt_create (void (*func)(void *), void *, struct thread **, 475 struct thread *, int, int, 476 const char *, ...) __printflike(7, 8); 477 extern void lwkt_exit (void) __dead2; 478 extern void lwkt_remove_tdallq (struct thread *); 479 480 #endif 481 482 #endif 483 484