1 /* $NetBSD: lwp.h,v 1.207 2020/04/24 03:22:06 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2010, 2019, 2020 5 * The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Nathan J. Williams and Andrew Doran. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef _SYS_LWP_H_ 34 #define _SYS_LWP_H_ 35 36 #if defined(_KERNEL) || defined(_KMEMUSER) 37 38 #include <sys/param.h> 39 #include <sys/time.h> 40 #include <sys/queue.h> 41 #include <sys/callout.h> 42 #include <sys/kcpuset.h> 43 #include <sys/mutex.h> 44 #include <sys/condvar.h> 45 #include <sys/signalvar.h> 46 #include <sys/sched.h> 47 #include <sys/specificdata.h> 48 #include <sys/syncobj.h> 49 #include <sys/resource.h> 50 51 #if defined(_KERNEL) 52 struct lwp; 53 /* forward declare this for <machine/cpu.h> so it can get l_cpu. */ 54 static __inline struct cpu_info *lwp_getcpu(struct lwp *); 55 #include <machine/cpu.h> /* curcpu() and cpu_info */ 56 #ifdef _KERNEL_OPT 57 #include "opt_kcov.h" 58 #include "opt_kmsan.h" 59 #endif 60 #endif 61 62 #include <machine/proc.h> /* Machine-dependent proc substruct. */ 63 64 /* 65 * Lightweight process. Field markings and the corresponding locks: 66 * 67 * a: proc_lock 68 * c: condition variable interlock, passed to cv_wait() 69 * l: *l_mutex 70 * p: l_proc->p_lock 71 * s: spc_mutex, which may or may not be referenced by l_mutex 72 * S: l_selcluster->sc_lock 73 * (: unlocked, stable 74 * !: unlocked, may only be reliably accessed by the LWP itself 75 * 76 * Fields are clustered together by usage (to increase the likelihood 77 * of cache hits) and by size (to reduce dead space in the structure). 78 */ 79 80 #include <sys/pcu.h> 81 82 struct lockdebug; 83 struct sysent; 84 85 struct lwp { 86 /* Scheduling and overall state. */ 87 TAILQ_ENTRY(lwp) l_runq; /* s: run queue */ 88 union { 89 void * info; /* s: scheduler-specific structure */ 90 u_int timeslice; /* l: time-quantum for SCHED_M2 */ 91 } l_sched; 92 struct cpu_info *volatile l_cpu;/* s: CPU we're on if LSONPROC */ 93 kmutex_t * volatile l_mutex; /* l: ptr to mutex on sched state */ 94 void *l_addr; /* l: PCB address; use lwp_getpcb() */ 95 struct mdlwp l_md; /* l: machine-dependent fields. */ 96 struct bintime l_rtime; /* l: real time */ 97 struct bintime l_stime; /* l: start time (while ONPROC) */ 98 int l_flag; /* l: misc flag values */ 99 u_int l_swtime; /* l: time swapped in or out */ 100 u_int l_rticks; /* l: Saved start time of run */ 101 u_int l_rticksum; /* l: Sum of ticks spent running */ 102 u_int l_slpticks; /* l: Saved start time of sleep */ 103 u_int l_slpticksum; /* l: Sum of ticks spent sleeping */ 104 int l_biglocks; /* l: biglock count before sleep */ 105 short l_stat; /* l: overall LWP status */ 106 short l_class; /* l: scheduling class */ 107 int l_kpriority; /* !: has kernel priority boost */ 108 pri_t l_kpribase; /* !: kernel priority base level */ 109 pri_t l_priority; /* l: scheduler priority */ 110 pri_t l_inheritedprio;/* l: inherited priority */ 111 pri_t l_protectprio; /* l: for PTHREAD_PRIO_PROTECT */ 112 pri_t l_auxprio; /* l: max(inherit,protect) priority */ 113 int l_protectdepth; /* l: for PTHREAD_PRIO_PROTECT */ 114 u_int l_cpticks; /* (: Ticks of CPU time */ 115 psetid_t l_psid; /* l: assigned processor-set ID */ 116 fixpt_t l_pctcpu; /* p: %cpu during l_swtime */ 117 fixpt_t l_estcpu; /* l: cpu time for SCHED_4BSD */ 118 volatile uint64_t l_ncsw; /* l: total context switches */ 119 volatile uint64_t l_nivcsw; /* l: involuntary context switches */ 120 SLIST_HEAD(, turnstile) l_pi_lenders; /* l: ts lending us priority */ 121 struct cpu_info *l_target_cpu; /* l: target CPU to migrate */ 122 struct lwpctl *l_lwpctl; /* p: lwpctl block kernel address */ 123 struct lcpage *l_lcpage; /* p: lwpctl containing page */ 124 kcpuset_t *l_affinity; /* l: CPU set for affinity */ 125 126 /* Synchronisation. */ 127 struct turnstile *l_ts; /* l: current turnstile */ 128 struct syncobj *l_syncobj; /* l: sync object operations set */ 129 LIST_ENTRY(lwp) l_sleepchain; /* l: sleep queue */ 130 wchan_t l_wchan; /* l: sleep address */ 131 const char *l_wmesg; /* l: reason for sleep */ 132 struct sleepq *l_sleepq; /* l: current sleep queue */ 133 callout_t l_timeout_ch; /* !: callout for tsleep */ 134 kcondvar_t l_waitcv; /* a: vfork() wait */ 135 u_int l_slptime; /* l: time since last blocked */ 136 bool l_vforkwaiting; /* a: vfork() waiting */ 137 138 /* User-space synchronization. */ 139 uintptr_t l___rsvd0; /* reserved for future use */ 140 uint32_t l___rsvd1; /* reserved for future use */ 141 142 #if PCU_UNIT_COUNT > 0 143 struct cpu_info * volatile l_pcu_cpu[PCU_UNIT_COUNT]; 144 uint32_t l_pcu_valid; 145 #endif 146 147 /* Process level and global state, misc. */ 148 lwpid_t l_lid; /* (: LWP identifier; local to proc */ 149 LIST_ENTRY(lwp) l_list; /* a: entry on list of all LWPs */ 150 void *l_ctxlink; /* p: uc_link {get,set}context */ 151 struct proc *l_proc; /* p: parent process */ 152 LIST_ENTRY(lwp) l_sibling; /* p: entry on proc's list of LWPs */ 153 char *l_name; /* (: name, optional */ 154 lwpid_t l_waiter; /* p: first LWP waiting on us */ 155 lwpid_t l_waitingfor; /* p: specific LWP we are waiting on */ 156 int l_prflag; /* p: process level flags */ 157 u_int l_refcnt; /* p: reference count on this LWP */ 158 159 /* State of select() or poll(). */ 160 int l_selflag; /* S: polling state flags */ 161 int l_selret; /* S: return value of select/poll */ 162 SLIST_HEAD(,selinfo) l_selwait; /* S: descriptors waited on */ 163 uintptr_t l_selrec; /* !: argument for selrecord() */ 164 struct selcluster *l_selcluster;/* !: associated cluster data */ 165 void * l_selbits; /* (: select() bit-field */ 166 size_t l_selni; /* (: size of a single bit-field */ 167 168 /* Signals. */ 169 int l_sigrestore; /* p: need to restore old sig mask */ 170 sigset_t l_sigwaitset; /* p: signals being waited for */ 171 kcondvar_t l_sigcv; /* p: for sigsuspend() */ 172 struct ksiginfo *l_sigwaited; /* p: delivered signals from set */ 173 sigpend_t *l_sigpendset; /* p: XXX issignal()/postsig() baton */ 174 LIST_ENTRY(lwp) l_sigwaiter; /* p: chain on list of waiting LWPs */ 175 stack_t l_sigstk; /* p: sp & on stack state variable */ 176 sigset_t l_sigmask; /* p: signal mask */ 177 sigpend_t l_sigpend; /* p: signals to this LWP */ 178 sigset_t l_sigoldmask; /* p: mask for sigpause */ 179 180 /* Private data. */ 181 specificdata_reference 182 l_specdataref; /* !: subsystem lwp-specific data */ 183 struct timespec l_ktrcsw; /* !: for ktrace CSW trace XXX */ 184 void *l_private; /* !: svr4-style lwp-private data */ 185 struct lwp *l_switchto; /* !: mi_switch: switch to this LWP */ 186 struct kauth_cred *l_cred; /* !: cached credentials */ 187 struct filedesc *l_fd; /* !: cached copy of proc::p_fd */ 188 void *l_emuldata; /* !: kernel lwp-private data */ 189 struct fstrans_lwp_info *l_fstrans; /* (: fstrans private data */ 190 u_short l_shlocks; /* !: lockdebug: shared locks held */ 191 u_short l_exlocks; /* !: lockdebug: excl. locks held */ 192 u_short l_psrefs; /* !: count of psref held */ 193 u_short l_blcnt; /* !: count of kernel_lock held */ 194 volatile int l_nopreempt; /* !: don't preempt me! */ 195 volatile u_int l_dopreempt; /* s: kernel preemption pending */ 196 int l_pflag; /* !: LWP private flags */ 197 int l_dupfd; /* !: side return from cloning devs XXX */ 198 const struct sysent * volatile l_sysent;/* !: currently active syscall */ 199 struct rusage l_ru; /* !: accounting information */ 200 uint64_t l_pfailtime; /* !: for kernel preemption */ 201 uintptr_t l_pfailaddr; /* !: for kernel preemption */ 202 uintptr_t l_pfaillock; /* !: for kernel preemption */ 203 _TAILQ_HEAD(,struct lockdebug,volatile) l_ld_locks;/* !: locks held by LWP */ 204 volatile void *l_ld_wanted; /* !: lock currently wanted by LWP */ 205 uintptr_t l_rwcallsite; /* !: rwlock actual callsite */ 206 int l_tcgen; /* !: for timecounter removal */ 207 208 /* These are only used by 'options SYSCALL_TIMES'. */ 209 uint32_t l_syscall_time; /* !: time epoch for current syscall */ 210 uint64_t *l_syscall_counter; /* !: counter for current process */ 211 212 struct kdtrace_thread *l_dtrace; /* (: DTrace-specific data. */ 213 214 #ifdef KMSAN 215 void *l_kmsan; /* !: KMSAN private data. */ 216 #endif 217 #ifdef KCOV 218 void *l_kcov; /* !: KCOV private data. */ 219 #endif 220 }; 221 222 /* 223 * UAREA_PCB_OFFSET: an offset of PCB structure in the uarea. MD code may 224 * define it in <machine/proc.h>, to indicate a different uarea layout. 225 */ 226 #ifndef UAREA_PCB_OFFSET 227 #define UAREA_PCB_OFFSET 0 228 #endif 229 230 LIST_HEAD(lwplist, lwp); /* A list of LWPs. */ 231 232 #ifdef _KERNEL 233 extern struct lwplist alllwp; /* List of all LWPs. */ 234 extern lwp_t lwp0; /* LWP for proc0. */ 235 extern int maxlwp __read_mostly; /* max number of lwps */ 236 #ifndef MAXLWP 237 #define MAXLWP 2048 238 #endif 239 #ifndef __HAVE_CPU_MAXLWP 240 #define cpu_maxlwp() MAXLWP 241 #endif 242 #endif 243 244 #endif /* _KERNEL || _KMEMUSER */ 245 246 /* 247 * These flags are kept in l_flag, and they are modified only with the LWP 248 * locked. 249 */ 250 #define LW_IDLE 0x00000001 /* Idle lwp. */ 251 #define LW_LWPCTL 0x00000002 /* Adjust lwpctl in userret */ 252 #define LW_STIMO 0x00000040 /* Sleep timed out */ 253 #define LW_SINTR 0x00000080 /* Sleep is interruptible. */ 254 #define LW_SYSTEM 0x00000200 /* Kernel thread */ 255 #define LW_DBGSUSPEND 0x00010000 /* Suspend by debugger */ 256 #define LW_WSUSPEND 0x00020000 /* Suspend before return to user */ 257 #define LW_BATCH 0x00040000 /* LWP tends to hog CPU */ 258 #define LW_WCORE 0x00080000 /* Stop for core dump on return to user */ 259 #define LW_WEXIT 0x00100000 /* Exit before return to user */ 260 #define LW_PENDSIG 0x01000000 /* Pending signal for us */ 261 #define LW_CANCELLED 0x02000000 /* tsleep should not sleep */ 262 #define LW_WREBOOT 0x08000000 /* System is rebooting, please suspend */ 263 #define LW_UNPARKED 0x10000000 /* Unpark op pending */ 264 #define LW_RUMP_CLEAR 0x40000000 /* Clear curlwp in RUMP scheduler */ 265 #define LW_RUMP_QEXIT 0x80000000 /* LWP should exit ASAP */ 266 267 /* 268 * The second set of flags is kept in l_pflag, and they are modified only by 269 * the LWP itself, or modified when it's known the LWP cannot be running. 270 * LP_RUNNING is typically updated with the LWP locked, but not always in 271 * the case of soft interrupt handlers. 272 */ 273 #define LP_KTRACTIVE 0x00000001 /* Executing ktrace operation */ 274 #define LP_KTRCSW 0x00000002 /* ktrace context switch marker */ 275 #define LP_KTRCSWUSER 0x00000004 /* ktrace context switch marker */ 276 /* 0x00000008 was LP_PIDLID */ 277 #define LP_OWEUPC 0x00000010 /* Owe user profiling tick */ 278 #define LP_MPSAFE 0x00000020 /* Starts life without kernel_lock */ 279 #define LP_INTR 0x00000040 /* Soft interrupt handler */ 280 #define LP_SYSCTLWRITE 0x00000080 /* sysctl write lock held */ 281 #define LP_MUSTJOIN 0x00000100 /* Must join kthread on exit */ 282 #define LP_SINGLESTEP 0x00000400 /* Single step thread in ptrace(2) */ 283 #define LP_TIMEINTR 0x00010000 /* Time this soft interrupt */ 284 #define LP_PREEMPTING 0x00020000 /* mi_switch called involuntarily */ 285 #define LP_RUNNING 0x20000000 /* Active on a CPU */ 286 #define LP_TELEPORT 0x40000000 /* Teleport to new CPU on preempt() */ 287 #define LP_BOUND 0x80000000 /* Bound to a CPU */ 288 289 /* 290 * The third set of flags is kept in l_prflag and they are modified only 291 * with p_lock held. 292 */ 293 #define LPR_DETACHED 0x00800000 /* Won't be waited for. */ 294 #define LPR_CRMOD 0x00000100 /* Credentials modified */ 295 #define LPR_DRAINING 0x80000000 /* Draining references before exiting */ 296 297 /* 298 * Mask indicating that there is "exceptional" work to be done on return to 299 * user. 300 */ 301 #define LW_USERRET \ 302 (LW_WEXIT | LW_PENDSIG | LW_WREBOOT | LW_WSUSPEND | LW_WCORE | LW_LWPCTL) 303 304 /* 305 * Status values. 306 * 307 * A note about LSRUN and LSONPROC: LSRUN indicates that a process is 308 * runnable but *not* yet running, i.e. is on a run queue. LSONPROC 309 * indicates that the process is actually executing on a CPU, i.e. 310 * it is no longer on a run queue. 311 * 312 * These values are set in stone and must not be reused with future changes. 313 */ 314 #define LSLARVAL 0 /* in pid table, but partially constructed */ 315 #define LSIDL 1 /* Process being created by fork. */ 316 #define LSRUN 2 /* Currently runnable. */ 317 #define LSSLEEP 3 /* Sleeping on an address. */ 318 #define LSSTOP 4 /* Process debugging or suspension. */ 319 #define LSZOMB 5 /* Awaiting collection by parent. */ 320 /* define LSDEAD 6 Process is almost a zombie. (removed in 5.0) */ 321 #define LSONPROC 7 /* Process is currently on a CPU. */ 322 #define LSSUSPENDED 8 /* Not running, not signalable. */ 323 324 #if defined(_KERNEL) || defined(_KMEMUSER) 325 static __inline void * 326 lwp_getpcb(struct lwp *l) 327 { 328 329 return l->l_addr; 330 } 331 #endif /* _KERNEL || _KMEMUSER */ 332 333 #ifdef _KERNEL 334 #define LWP_CACHE_CREDS(l, p) \ 335 do { \ 336 (void)p; \ 337 if (__predict_false((l)->l_prflag & LPR_CRMOD)) \ 338 lwp_update_creds(l); \ 339 } while (/* CONSTCOND */ 0) 340 341 void lwpinit(void); 342 void lwp0_init(void); 343 344 void lwp_startup(lwp_t *, lwp_t *); 345 void startlwp(void *); 346 347 int lwp_locked(lwp_t *, kmutex_t *); 348 kmutex_t *lwp_setlock(lwp_t *, kmutex_t *); 349 void lwp_unlock_to(lwp_t *, kmutex_t *); 350 int lwp_trylock(lwp_t *); 351 void lwp_addref(lwp_t *); 352 lwp_t * lwp_getref_lwpid(lwpid_t); 353 void lwp_delref(lwp_t *); 354 void lwp_delref2(lwp_t *); 355 bool lwp_drainrefs(lwp_t *); 356 bool lwp_alive(lwp_t *); 357 lwp_t *lwp_find_first(proc_t *); 358 359 int lwp_wait(lwp_t *, lwpid_t, lwpid_t *, bool); 360 void lwp_continue(lwp_t *); 361 void lwp_unsleep(lwp_t *, bool); 362 void lwp_unstop(lwp_t *); 363 void lwp_exit(lwp_t *); 364 int lwp_suspend(lwp_t *, lwp_t *); 365 int lwp_create1(lwp_t *, const void *, size_t, u_long, lwpid_t *); 366 void lwp_start(lwp_t *, int); 367 void lwp_update_creds(lwp_t *); 368 void lwp_migrate(lwp_t *, struct cpu_info *); 369 lwp_t * lwp_find2(pid_t, lwpid_t); 370 lwp_t * lwp_find(proc_t *, int); 371 void lwp_userret(lwp_t *); 372 void lwp_need_userret(lwp_t *); 373 void lwp_free(lwp_t *, bool, bool); 374 uint64_t lwp_pctr(void); 375 int lwp_setprivate(lwp_t *, void *); 376 int do_lwp_create(lwp_t *, void *, u_long, lwp_t **, const sigset_t *, 377 const stack_t *); 378 379 void lwp_thread_cleanup(lwp_t *); 380 381 void lwpinit_specificdata(void); 382 int lwp_specific_key_create(specificdata_key_t *, specificdata_dtor_t); 383 void lwp_specific_key_delete(specificdata_key_t); 384 void lwp_initspecific(lwp_t *); 385 void lwp_finispecific(lwp_t *); 386 void *lwp_getspecific(specificdata_key_t); 387 #if defined(_LWP_API_PRIVATE) 388 void *_lwp_getspecific_by_lwp(lwp_t *, specificdata_key_t); 389 #endif 390 void lwp_setspecific(specificdata_key_t, void *); 391 void lwp_setspecific_by_lwp(lwp_t *, specificdata_key_t, void *); 392 393 /* Syscalls. */ 394 int lwp_park(clockid_t, int, struct timespec *); 395 int lwp_unpark(const lwpid_t *, const u_int); 396 397 /* DDB. */ 398 void lwp_whatis(uintptr_t, void (*)(const char *, ...) __printflike(1, 2)); 399 400 /* 401 * Lock an LWP. XXX _MODULE 402 */ 403 static __inline void 404 lwp_lock(lwp_t *l) 405 { 406 kmutex_t *old = l->l_mutex; 407 408 /* 409 * Note: mutex_spin_enter() will have posted a read barrier. 410 * Re-test l->l_mutex. If it has changed, we need to try again. 411 */ 412 mutex_spin_enter(old); 413 while (__predict_false(l->l_mutex != old)) { 414 mutex_spin_exit(old); 415 old = l->l_mutex; 416 mutex_spin_enter(old); 417 } 418 } 419 420 /* 421 * Unlock an LWP. XXX _MODULE 422 */ 423 static __inline void 424 lwp_unlock(lwp_t *l) 425 { 426 mutex_spin_exit(l->l_mutex); 427 } 428 429 static __inline void 430 lwp_changepri(lwp_t *l, pri_t pri) 431 { 432 KASSERT(mutex_owned(l->l_mutex)); 433 434 if (l->l_priority == pri) 435 return; 436 437 (*l->l_syncobj->sobj_changepri)(l, pri); 438 KASSERT(l->l_priority == pri); 439 } 440 441 static __inline void 442 lwp_lendpri(lwp_t *l, pri_t pri) 443 { 444 KASSERT(mutex_owned(l->l_mutex)); 445 446 (*l->l_syncobj->sobj_lendpri)(l, pri); 447 KASSERT(l->l_inheritedprio == pri); 448 } 449 450 static __inline pri_t 451 lwp_eprio(lwp_t *l) 452 { 453 pri_t pri; 454 455 pri = l->l_priority; 456 if ((l->l_flag & LW_SYSTEM) == 0 && l->l_kpriority && pri < PRI_KERNEL) 457 pri = (pri >> 1) + l->l_kpribase; 458 return MAX(l->l_auxprio, pri); 459 } 460 461 int lwp_create(lwp_t *, struct proc *, vaddr_t, int, void *, size_t, 462 void (*)(void *), void *, lwp_t **, int, const sigset_t *, const stack_t *); 463 464 /* 465 * XXX _MODULE 466 * We should provide real stubs for the below that modules can use. 467 */ 468 469 static __inline void 470 spc_lock(struct cpu_info *ci) 471 { 472 mutex_spin_enter(ci->ci_schedstate.spc_mutex); 473 } 474 475 static __inline void 476 spc_unlock(struct cpu_info *ci) 477 { 478 mutex_spin_exit(ci->ci_schedstate.spc_mutex); 479 } 480 481 static __inline void 482 spc_dlock(struct cpu_info *ci1, struct cpu_info *ci2) 483 { 484 struct schedstate_percpu *spc1 = &ci1->ci_schedstate; 485 struct schedstate_percpu *spc2 = &ci2->ci_schedstate; 486 487 KASSERT(ci1 != ci2); 488 if (ci1 < ci2) { 489 mutex_spin_enter(spc1->spc_mutex); 490 mutex_spin_enter(spc2->spc_mutex); 491 } else { 492 mutex_spin_enter(spc2->spc_mutex); 493 mutex_spin_enter(spc1->spc_mutex); 494 } 495 } 496 497 /* 498 * Allow machine-dependent code to override curlwp in <machine/cpu.h> for 499 * its own convenience. Otherwise, we declare it as appropriate. 500 */ 501 #if !defined(curlwp) 502 #if defined(MULTIPROCESSOR) 503 #define curlwp curcpu()->ci_curlwp /* Current running LWP */ 504 #else 505 extern struct lwp *curlwp; /* Current running LWP */ 506 #endif /* MULTIPROCESSOR */ 507 #endif /* ! curlwp */ 508 #define curproc (curlwp->l_proc) 509 510 /* 511 * This provide a way for <machine/cpu.h> to get l_cpu for curlwp before 512 * struct lwp is defined. 513 */ 514 static __inline struct cpu_info * 515 lwp_getcpu(struct lwp *l) 516 { 517 return l->l_cpu; 518 } 519 520 static __inline bool 521 CURCPU_IDLE_P(void) 522 { 523 struct cpu_info *ci = curcpu(); 524 return ci->ci_onproc == ci->ci_data.cpu_idlelwp; 525 } 526 527 /* 528 * Disable and re-enable preemption. Only for low-level kernel 529 * use. Device drivers and anything that could potentially be 530 * compiled as a module should use kpreempt_disable() and 531 * kpreempt_enable(). 532 */ 533 static __inline void 534 KPREEMPT_DISABLE(lwp_t *l) 535 { 536 537 KASSERT(l == curlwp); 538 l->l_nopreempt++; 539 __insn_barrier(); 540 } 541 542 static __inline void 543 KPREEMPT_ENABLE(lwp_t *l) 544 { 545 546 KASSERT(l == curlwp); 547 KASSERT(l->l_nopreempt > 0); 548 __insn_barrier(); 549 if (--l->l_nopreempt != 0) 550 return; 551 __insn_barrier(); 552 if (__predict_false(l->l_dopreempt)) 553 kpreempt(0); 554 __insn_barrier(); 555 } 556 557 /* For lwp::l_dopreempt */ 558 #define DOPREEMPT_ACTIVE 0x01 559 #define DOPREEMPT_COUNTED 0x02 560 561 /* 562 * Prevent curlwp from migrating between CPUs between curlwp_bind and 563 * curlwp_bindx. One use case is psref(9) that has a contract that 564 * forbids migrations. 565 */ 566 static __inline int 567 curlwp_bind(void) 568 { 569 int bound; 570 571 bound = curlwp->l_pflag & LP_BOUND; 572 curlwp->l_pflag |= LP_BOUND; 573 __insn_barrier(); 574 575 return bound; 576 } 577 578 static __inline void 579 curlwp_bindx(int bound) 580 { 581 582 KASSERT(curlwp->l_pflag & LP_BOUND); 583 __insn_barrier(); 584 curlwp->l_pflag ^= bound ^ LP_BOUND; 585 } 586 587 #endif /* _KERNEL */ 588 589 /* Flags for _lwp_create(), as per Solaris. */ 590 #define LWP_DETACHED 0x00000040 591 #define LWP_SUSPENDED 0x00000080 592 593 /* Kernel-internal flags for LWP creation. */ 594 /* 0x40000000 was LWP_PIDLID */ 595 #define LWP_VFORK 0x80000000 596 597 #endif /* !_SYS_LWP_H_ */ 598