/* * Copyright (c) 2003 Matthew Dillon All rights reserved. * Copyright (c) 1997, Stefan Esser All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * $FreeBSD: src/sys/kern/kern_intr.c,v 1.24.2.1 2001/10/14 20:05:50 luigi Exp $ * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct intr_info; typedef struct intrec { struct intrec *next; struct intr_info *info; inthand2_t *handler; void *argument; char *name; int intr; int intr_flags; struct lwkt_serialize *serializer; } *intrec_t; struct intr_info { intrec_t i_reclist; struct thread *i_thread; /* don't embed struct thread */ struct random_softc i_random; long i_count; /* interrupts dispatched */ int i_running; short i_mplock_required; short i_flags; int i_fast; int i_slow; int i_state; int i_errorticks; unsigned long i_straycount; int i_cpuid; int i_intr; }; struct intr_info_block { struct intr_info ary[MAXCPU][MAX_INTS]; }; static struct intr_info_block *intr_block; static struct intr_info *swi_info_ary[MAX_SOFTINTS]; static int max_installed_hard_intr[MAXCPU]; MALLOC_DEFINE(M_INTRMNG, "intrmng", "interrupt management"); #define EMERGENCY_INTR_POLLING_FREQ_MAX 20000 /* * Assert that callers into interrupt handlers don't return with * dangling tokens, spinlocks, or mp locks. */ #ifdef INVARIANTS #define TD_INVARIANTS_DECLARE \ int spincount; \ lwkt_tokref_t curstop #define TD_INVARIANTS_GET(td) \ do { \ spincount = (td)->td_gd->gd_spinlocks; \ curstop = (td)->td_toks_stop; \ } while(0) #define TD_INVARIANTS_TEST(td, name) \ do { \ KASSERT(spincount == (td)->td_gd->gd_spinlocks, \ ("spincount mismatch after interrupt handler %s", \ name)); \ KASSERT(curstop == (td)->td_toks_stop, \ ("token count mismatch after interrupt handler %s", \ name)); \ } while(0) #else /* !INVARIANTS */ #define TD_INVARIANTS_DECLARE #define TD_INVARIANTS_GET(td) #define TD_INVARIANTS_TEST(td, name) #endif /* ndef INVARIANTS */ static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS); static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS); static void emergency_intr_timer_callback(systimer_t, int, struct intrframe *); static void ithread_handler(void *arg); static void ithread_emergency(void *arg); static void report_stray_interrupt(struct intr_info *info, const char *func); static void int_moveto_destcpu(int *, int); static void int_moveto_origcpu(int, int); static void sched_ithd_intern(struct intr_info *info); static struct systimer emergency_intr_timer[MAXCPU]; static struct thread *emergency_intr_thread[MAXCPU]; #define ISTATE_NOTHREAD 0 #define ISTATE_NORMAL 1 #define ISTATE_LIVELOCKED 2 static int livelock_limit = 40000; static int livelock_limit_hi = 120000; static int livelock_lowater = 20000; static int livelock_debug = -1; SYSCTL_INT(_kern, OID_AUTO, livelock_limit, CTLFLAG_RW, &livelock_limit, 0, "Livelock interrupt rate limit"); SYSCTL_INT(_kern, OID_AUTO, livelock_limit_hi, CTLFLAG_RW, &livelock_limit_hi, 0, "Livelock interrupt rate limit (high frequency)"); SYSCTL_INT(_kern, OID_AUTO, livelock_lowater, CTLFLAG_RW, &livelock_lowater, 0, "Livelock low-water mark restore"); SYSCTL_INT(_kern, OID_AUTO, livelock_debug, CTLFLAG_RW, &livelock_debug, 0, "Livelock debug intr#"); static int emergency_intr_enable = 0; /* emergency interrupt polling */ TUNABLE_INT("kern.emergency_intr_enable", &emergency_intr_enable); SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_enable, CTLTYPE_INT | CTLFLAG_RW, 0, 0, sysctl_emergency_enable, "I", "Emergency Interrupt Poll Enable"); static int emergency_intr_freq = 10; /* emergency polling frequency */ TUNABLE_INT("kern.emergency_intr_freq", &emergency_intr_freq); SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_freq, CTLTYPE_INT | CTLFLAG_RW, 0, 0, sysctl_emergency_freq, "I", "Emergency Interrupt Poll Frequency"); /* * Sysctl support routines */ static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS) { int error, enabled, cpuid, freq, origcpu; enabled = emergency_intr_enable; error = sysctl_handle_int(oidp, &enabled, 0, req); if (error || req->newptr == NULL) return error; emergency_intr_enable = enabled; if (emergency_intr_enable) freq = emergency_intr_freq; else freq = 1; origcpu = mycpuid; for (cpuid = 0; cpuid < ncpus; ++cpuid) { lwkt_migratecpu(cpuid); systimer_adjust_periodic(&emergency_intr_timer[cpuid], freq); } lwkt_migratecpu(origcpu); return 0; } static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS) { int error, phz, cpuid, freq, origcpu; phz = emergency_intr_freq; error = sysctl_handle_int(oidp, &phz, 0, req); if (error || req->newptr == NULL) return error; if (phz <= 0) return EINVAL; else if (phz > EMERGENCY_INTR_POLLING_FREQ_MAX) phz = EMERGENCY_INTR_POLLING_FREQ_MAX; emergency_intr_freq = phz; if (emergency_intr_enable) freq = emergency_intr_freq; else freq = 1; origcpu = mycpuid; for (cpuid = 0; cpuid < ncpus; ++cpuid) { lwkt_migratecpu(cpuid); systimer_adjust_periodic(&emergency_intr_timer[cpuid], freq); } lwkt_migratecpu(origcpu); return 0; } /* * Register an SWI or INTerrupt handler. */ void * register_swi(int intr, inthand2_t *handler, void *arg, const char *name, struct lwkt_serialize *serializer, int cpuid) { if (intr < FIRST_SOFTINT || intr >= MAX_INTS) panic("register_swi: bad intr %d", intr); if (cpuid < 0) cpuid = intr % ncpus; return(register_int(intr, handler, arg, name, serializer, 0, cpuid)); } void * register_swi_mp(int intr, inthand2_t *handler, void *arg, const char *name, struct lwkt_serialize *serializer, int cpuid) { if (intr < FIRST_SOFTINT || intr >= MAX_INTS) panic("register_swi: bad intr %d", intr); if (cpuid < 0) cpuid = intr % ncpus; return(register_int(intr, handler, arg, name, serializer, INTR_MPSAFE, cpuid)); } void * register_int(int intr, inthand2_t *handler, void *arg, const char *name, struct lwkt_serialize *serializer, int intr_flags, int cpuid) { struct intr_info *info; struct intrec **list; intrec_t rec = NULL; int orig_cpuid; KKASSERT(cpuid >= 0 && cpuid < ncpus); if (intr < 0 || intr >= MAX_INTS) panic("register_int: bad intr %d", intr); if (name == NULL) name = "???"; info = &intr_block->ary[cpuid][intr]; int_moveto_destcpu(&orig_cpuid, cpuid); /* * This intr has been registered as exclusive one, so * it can't shared. */ if (info->i_flags & INTR_EXCL) goto done; /* * This intr has been registered as shared one, so it * can't be used for exclusive handler. */ list = &info->i_reclist; if ((intr_flags & INTR_EXCL) && *list != NULL) goto done; /* * Construct an interrupt handler record */ rec = kmalloc(sizeof(struct intrec), M_DEVBUF, M_INTWAIT); rec->name = kmalloc(strlen(name) + 1, M_DEVBUF, M_INTWAIT); strcpy(rec->name, name); rec->info = info; rec->handler = handler; rec->argument = arg; rec->intr = intr; rec->intr_flags = intr_flags; rec->next = NULL; rec->serializer = serializer; /* * Create an emergency polling thread and set up a systimer to wake * it up. objcache isn't operational yet so use kmalloc. * * objcache may not be operational yet, use kmalloc(). */ if (emergency_intr_thread[cpuid] == NULL) { emergency_intr_thread[cpuid] = kmalloc(sizeof(struct thread), M_DEVBUF, M_INTWAIT | M_ZERO); lwkt_create(ithread_emergency, NULL, NULL, emergency_intr_thread[cpuid], TDF_NOSTART | TDF_INTTHREAD, cpuid, "ithreadE %d", cpuid); systimer_init_periodic_nq(&emergency_intr_timer[cpuid], emergency_intr_timer_callback, emergency_intr_thread[cpuid], (emergency_intr_enable ? emergency_intr_freq : 1)); } /* * Create an interrupt thread if necessary, leave it in an unscheduled * state. */ if (info->i_state == ISTATE_NOTHREAD) { info->i_state = ISTATE_NORMAL; info->i_thread = kmalloc(sizeof(struct thread), M_DEVBUF, M_INTWAIT | M_ZERO); lwkt_create(ithread_handler, (void *)(intptr_t)intr, NULL, info->i_thread, TDF_NOSTART | TDF_INTTHREAD, cpuid, "ithread%d %d", intr, cpuid); if (intr >= FIRST_SOFTINT) lwkt_setpri(info->i_thread, TDPRI_SOFT_NORM); else lwkt_setpri(info->i_thread, TDPRI_INT_MED); info->i_thread->td_preemptable = lwkt_preempt; } /* * Keep track of how many fast and slow interrupts we have. * Set i_mplock_required if any handler in the chain requires * the MP lock to operate. */ if ((intr_flags & INTR_MPSAFE) == 0) { info->i_mplock_required = 1; kprintf("interrupt uses mplock: %s\n", name); } if (intr_flags & INTR_CLOCK) { atomic_set_int(&info->i_thread->td_flags, TDF_CLKTHREAD); ++info->i_fast; } else { ++info->i_slow; } info->i_flags |= (intr_flags & INTR_EXCL); if (info->i_slow + info->i_fast == 1 && (intr_flags & INTR_HIFREQ)) { /* * Allow high frequency interrupt, if this intr is not * shared yet. */ info->i_flags |= INTR_HIFREQ; } else { info->i_flags &= ~INTR_HIFREQ; } /* * Enable random number generation keying off of this interrupt. */ if ((intr_flags & INTR_NOENTROPY) == 0 && info->i_random.sc_enabled == 0) { info->i_random.sc_enabled = 1; info->i_random.sc_intr = intr; } /* * Add the record to the interrupt list. */ crit_enter(); while (*list != NULL) list = &(*list)->next; *list = rec; crit_exit(); /* * Update max_installed_hard_intr to make the emergency intr poll * a bit more efficient. */ if (intr < FIRST_SOFTINT) { if (max_installed_hard_intr[cpuid] <= intr) max_installed_hard_intr[cpuid] = intr + 1; } if (intr >= FIRST_SOFTINT) swi_info_ary[intr - FIRST_SOFTINT] = info; /* * Setup the machine level interrupt vector */ if (intr < FIRST_SOFTINT && info->i_slow + info->i_fast == 1) machintr_intr_setup(intr, intr_flags); done: int_moveto_origcpu(orig_cpuid, cpuid); return(rec); } void unregister_swi(void *id, int intr, int cpuid) { if (cpuid < 0) cpuid = intr % ncpus; unregister_int(id, cpuid); } void unregister_int(void *id, int cpuid) { struct intr_info *info; struct intrec **list; intrec_t rec; int intr, orig_cpuid; KKASSERT(cpuid >= 0 && cpuid < ncpus); intr = ((intrec_t)id)->intr; if (intr < 0 || intr >= MAX_INTS) panic("register_int: bad intr %d", intr); info = &intr_block->ary[cpuid][intr]; int_moveto_destcpu(&orig_cpuid, cpuid); /* * Remove the interrupt descriptor, adjust the descriptor count, * and teardown the machine level vector if this was the last interrupt. */ crit_enter(); list = &info->i_reclist; while ((rec = *list) != NULL) { if (rec == id) break; list = &rec->next; } if (rec) { intrec_t rec0; *list = rec->next; if (rec->intr_flags & INTR_CLOCK) --info->i_fast; else --info->i_slow; if (intr < FIRST_SOFTINT && info->i_fast + info->i_slow == 0) machintr_intr_teardown(intr); /* * Clear i_mplock_required if no handlers in the chain require the * MP lock. */ for (rec0 = info->i_reclist; rec0; rec0 = rec0->next) { if ((rec0->intr_flags & INTR_MPSAFE) == 0) break; } if (rec0 == NULL) info->i_mplock_required = 0; } if (info->i_reclist == NULL) { info->i_flags = 0; if (intr >= FIRST_SOFTINT) swi_info_ary[intr - FIRST_SOFTINT] = NULL; } else if (info->i_fast + info->i_slow == 1 && (info->i_reclist->intr_flags & INTR_HIFREQ)) { /* Unshared high frequency interrupt. */ info->i_flags |= INTR_HIFREQ; } crit_exit(); int_moveto_origcpu(orig_cpuid, cpuid); /* * Free the record. */ if (rec != NULL) { kfree(rec->name, M_DEVBUF); kfree(rec, M_DEVBUF); } else { kprintf("warning: unregister_int: int %d handler for %s not found\n", intr, ((intrec_t)id)->name); } } long get_interrupt_counter(int intr, int cpuid) { struct intr_info *info; KKASSERT(cpuid >= 0 && cpuid < ncpus); if (intr < 0 || intr >= MAX_INTS) panic("register_int: bad intr %d", intr); info = &intr_block->ary[cpuid][intr]; return(info->i_count); } void register_randintr(int intr) { struct intr_info *info; int cpuid; if (intr < 0 || intr >= MAX_INTS) panic("register_randintr: bad intr %d", intr); for (cpuid = 0; cpuid < ncpus; ++cpuid) { info = &intr_block->ary[cpuid][intr]; info->i_random.sc_intr = intr; info->i_random.sc_enabled = 1; } } void unregister_randintr(int intr) { struct intr_info *info; int cpuid; if (intr < 0 || intr >= MAX_INTS) panic("register_swi: bad intr %d", intr); for (cpuid = 0; cpuid < ncpus; ++cpuid) { info = &intr_block->ary[cpuid][intr]; info->i_random.sc_enabled = -1; } } int next_registered_randintr(int intr) { struct intr_info *info; if (intr < 0 || intr >= MAX_INTS) panic("register_swi: bad intr %d", intr); while (intr < MAX_INTS) { int cpuid; for (cpuid = 0; cpuid < ncpus; ++cpuid) { info = &intr_block->ary[cpuid][intr]; if (info->i_random.sc_enabled > 0) return intr; } ++intr; } return intr; } /* * Dispatch an interrupt. If there's nothing to do we have a stray * interrupt and can just return, leaving the interrupt masked. * * We need to schedule the interrupt and set its i_running bit. If * we are not on the interrupt thread's cpu we have to send a message * to the correct cpu that will issue the desired action (interlocking * with the interrupt thread's critical section). We do NOT attempt to * reschedule interrupts whos i_running bit is already set because * this would prematurely wakeup a livelock-limited interrupt thread. * * i_running is only tested/set on the same cpu as the interrupt thread. * * We are NOT in a critical section, which will allow the scheduled * interrupt to preempt us. The MP lock might *NOT* be held here. */ static void sched_ithd_remote(void *arg) { sched_ithd_intern(arg); } static void sched_ithd_intern(struct intr_info *info) { ++info->i_count; if (info->i_state != ISTATE_NOTHREAD) { if (info->i_reclist == NULL) { report_stray_interrupt(info, "sched_ithd"); } else { if (info->i_thread->td_gd == mycpu) { if (info->i_running == 0) { info->i_running = 1; if (info->i_state != ISTATE_LIVELOCKED) lwkt_schedule(info->i_thread); /* MIGHT PREEMPT */ } } else { lwkt_send_ipiq(info->i_thread->td_gd, sched_ithd_remote, info); } } } else { report_stray_interrupt(info, "sched_ithd"); } } void sched_ithd_soft(int intr) { struct intr_info *info; KKASSERT(intr >= FIRST_SOFTINT && intr < MAX_INTS); info = swi_info_ary[intr - FIRST_SOFTINT]; if (info != NULL) { sched_ithd_intern(info); } else { kprintf("unregistered softint %d got scheduled on cpu%d\n", intr, mycpuid); } } void sched_ithd_hard(int intr) { KKASSERT(intr >= 0 && intr < MAX_HARDINTS); sched_ithd_intern(&intr_block->ary[mycpuid][intr]); } #ifdef _KERNEL_VIRTUAL void sched_ithd_hard_virtual(int intr) { KKASSERT(intr >= 0 && intr < MAX_HARDINTS); sched_ithd_intern(&intr_block->ary[0][intr]); } void * register_int_virtual(int intr, inthand2_t *handler, void *arg, const char *name, struct lwkt_serialize *serializer, int intr_flags) { return register_int(intr, handler, arg, name, serializer, intr_flags, 0); } void unregister_int_virtual(void *id) { unregister_int(id, 0); } #endif /* _KERN_VIRTUAL */ static void report_stray_interrupt(struct intr_info *info, const char *func) { ++info->i_straycount; if (info->i_straycount < 10) { if (info->i_errorticks == ticks) return; info->i_errorticks = ticks; kprintf("%s: stray interrupt %d on cpu%d\n", func, info->i_intr, mycpuid); } else if (info->i_straycount == 10) { kprintf("%s: %ld stray interrupts %d on cpu%d - " "there will be no further reports\n", func, info->i_straycount, info->i_intr, mycpuid); } } /* * This is run from a periodic SYSTIMER (and thus must be MP safe, the BGL * might not be held). */ static void ithread_livelock_wakeup(systimer_t st, int in_ipi __unused, struct intrframe *frame __unused) { struct intr_info *info; info = &intr_block->ary[mycpuid][(int)(intptr_t)st->data]; if (info->i_state != ISTATE_NOTHREAD) lwkt_schedule(info->i_thread); } /* * Schedule ithread within fast intr handler * * Temporarily bump the current thread's td_nest_count to prevent deep * preemptions and splz/doreti stacks. */ static __inline void ithread_fast_sched(int intr, thread_t td) { ++td->td_nest_count; crit_exit_quick(td); sched_ithd_hard(intr); crit_enter_quick(td); --td->td_nest_count; } /* * This function is called directly from the ICU or APIC vector code assembly * to process an interrupt. The critical section and interrupt deferral * checks have already been done but the function is entered WITHOUT * a critical section held. The BGL may or may not be held. * * Must return non-zero if we do not want the vector code to re-enable * the interrupt (which we don't if we have to schedule the interrupt) */ int ithread_fast_handler(struct intrframe *frame); int ithread_fast_handler(struct intrframe *frame) { int intr; struct intr_info *info; struct intrec **list; int must_schedule; int got_mplock; TD_INVARIANTS_DECLARE; intrec_t rec, nrec; globaldata_t gd; thread_t td; intr = frame->if_vec; gd = mycpu; td = curthread; /* We must be in critical section. */ KKASSERT(td->td_critcount); /* Race condition during early boot */ if (intr_block == NULL) return 0; info = &intr_block->ary[mycpuid][intr]; /* * If we are not processing any FAST interrupts, just schedule the thing. */ if (info->i_fast == 0) { ++gd->gd_cnt.v_intr; ithread_fast_sched(intr, td); return(1); } /* * This should not normally occur since interrupts ought to be * masked if the ithread has been scheduled or is running. */ if (info->i_running) return(1); /* * Bump the interrupt nesting level to process any FAST interrupts. * Obtain the MP lock as necessary. If the MP lock cannot be obtained, * schedule the interrupt thread to deal with the issue instead. * * To reduce overhead, just leave the MP lock held once it has been * obtained. */ ++gd->gd_intr_nesting_level; ++gd->gd_cnt.v_intr; must_schedule = info->i_slow; got_mplock = 0; TD_INVARIANTS_GET(td); list = &info->i_reclist; for (rec = *list; rec; rec = nrec) { /* rec may be invalid after call */ nrec = rec->next; if (rec->intr_flags & INTR_CLOCK) { if ((rec->intr_flags & INTR_MPSAFE) == 0 && got_mplock == 0) { if (try_mplock() == 0) { /* Couldn't get the MP lock; just schedule it. */ must_schedule = 1; break; } got_mplock = 1; } if (rec->serializer) { must_schedule += lwkt_serialize_handler_try( rec->serializer, rec->handler, rec->argument, frame); } else { rec->handler(rec->argument, frame); } TD_INVARIANTS_TEST(td, rec->name); } } /* * Cleanup */ --gd->gd_intr_nesting_level; if (got_mplock) rel_mplock(); /* * If we had a problem, or mixed fast and slow interrupt handlers are * registered, schedule the ithread to catch the missed records (it * will just re-run all of them). A return value of 0 indicates that * all handlers have been run and the interrupt can be re-enabled, and * a non-zero return indicates that the interrupt thread controls * re-enablement. */ if (must_schedule > 0) ithread_fast_sched(intr, td); else if (must_schedule == 0) ++info->i_count; return(must_schedule); } /* * Interrupt threads run this as their main loop. * * The handler begins execution outside a critical section and no MP lock. * * The i_running state starts at 0. When an interrupt occurs, the hardware * interrupt is disabled and sched_ithd_hard(). The HW interrupt remains * disabled until all routines have run. We then call machintr_intr_enable() * to reenable the HW interrupt and deschedule us until the next interrupt. * * We are responsible for atomically checking i_running. i_running for our * irq is only set in the context of our cpu, so a critical section is a * sufficient interlock. */ #define LIVELOCK_TIMEFRAME(freq) ((freq) >> 2) /* 1/4 second */ static void ithread_handler(void *arg) { struct intr_info *info; int use_limit; uint32_t lseconds; int intr, cpuid = mycpuid; int mpheld; struct intrec **list; intrec_t rec, nrec; globaldata_t gd; struct systimer ill_timer; /* enforced freq. timer */ u_int ill_count; /* interrupt livelock counter */ int upper_limit; /* interrupt livelock upper limit */ TD_INVARIANTS_DECLARE; ill_count = 0; intr = (int)(intptr_t)arg; info = &intr_block->ary[cpuid][intr]; list = &info->i_reclist; /* * The loop must be entered with one critical section held. The thread * does not hold the mplock on startup. */ gd = mycpu; lseconds = gd->gd_time_seconds; crit_enter_gd(gd); mpheld = 0; for (;;) { /* * The chain is only considered MPSAFE if all its interrupt handlers * are MPSAFE. However, if intr_mpsafe has been turned off we * always operate with the BGL. */ if (info->i_mplock_required != mpheld) { if (info->i_mplock_required) { KKASSERT(mpheld == 0); get_mplock(); mpheld = 1; } else { KKASSERT(mpheld != 0); rel_mplock(); mpheld = 0; } } TD_INVARIANTS_GET(gd->gd_curthread); /* * If an interrupt is pending, clear i_running and execute the * handlers. Note that certain types of interrupts can re-trigger * and set i_running again. * * Each handler is run in a critical section. Note that we run both * FAST and SLOW designated service routines. */ if (info->i_running) { ++ill_count; info->i_running = 0; if (*list == NULL) report_stray_interrupt(info, "ithread_handler"); for (rec = *list; rec; rec = nrec) { /* rec may be invalid after call */ nrec = rec->next; if (rec->handler == NULL) { kprintf("NULL HANDLER %s\n", rec->name); } else if (rec->serializer) { lwkt_serialize_handler_call(rec->serializer, rec->handler, rec->argument, NULL); } else { rec->handler(rec->argument, NULL); } TD_INVARIANTS_TEST(gd->gd_curthread, rec->name); } } /* * This is our interrupt hook to add rate randomness to the random * number generator. */ if (info->i_random.sc_enabled > 0) add_interrupt_randomness(intr); /* * Unmask the interrupt to allow it to trigger again. This only * applies to certain types of interrupts (typ level interrupts). * This can result in the interrupt retriggering, but the retrigger * will not be processed until we cycle our critical section. * * Only unmask interrupts while handlers are installed. It is * possible to hit a situation where no handlers are installed * due to a device driver livelocking and then tearing down its * interrupt on close (the parallel bus being a good example). */ if (intr < FIRST_SOFTINT && *list) machintr_intr_enable(intr); /* * Do a quick exit/enter to catch any higher-priority interrupt * sources, such as the statclock, so thread time accounting * will still work. This may also cause an interrupt to re-trigger. */ crit_exit_gd(gd); crit_enter_gd(gd); /* * LIVELOCK STATE MACHINE */ switch(info->i_state) { case ISTATE_NORMAL: /* * Reset the count each second. */ if (lseconds != gd->gd_time_seconds) { lseconds = gd->gd_time_seconds; ill_count = 0; } /* * If we did not exceed the frequency limit, we are done. * If the interrupt has not retriggered we deschedule ourselves. */ if (info->i_flags & INTR_HIFREQ) upper_limit = livelock_limit_hi; else upper_limit = livelock_limit; if (ill_count <= upper_limit) { if (info->i_running == 0) { lwkt_deschedule_self(gd->gd_curthread); lwkt_switch(); } break; } /* * Otherwise we are livelocked. Set up a periodic systimer * to wake the thread up at the limit frequency. */ kprintf("intr %d on cpu%d at %d/%d hz, livelocked limit engaged!\n", intr, cpuid, ill_count, upper_limit); info->i_state = ISTATE_LIVELOCKED; if ((use_limit = upper_limit) < 100) use_limit = 100; else if (use_limit > 500000) use_limit = 500000; systimer_init_periodic_nq(&ill_timer, ithread_livelock_wakeup, (void *)(intptr_t)intr, use_limit); /* fall through */ case ISTATE_LIVELOCKED: /* * Wait for our periodic timer to go off. Since the interrupt * has re-armed it can still set i_running, but it will not * reschedule us while we are in a livelocked state. */ lwkt_deschedule_self(gd->gd_curthread); lwkt_switch(); /* * Check once a second to see if the livelock condition no * longer applies. */ if (lseconds != gd->gd_time_seconds) { lseconds = gd->gd_time_seconds; if (ill_count < livelock_lowater) { info->i_state = ISTATE_NORMAL; systimer_del(&ill_timer); kprintf("intr %d on cpu%d at %d/%d hz, livelock removed\n", intr, cpuid, ill_count, livelock_lowater); } else if (livelock_debug == intr || (bootverbose && cold)) { kprintf("intr %d on cpu%d at %d/%d hz, in livelock\n", intr, cpuid, ill_count, livelock_lowater); } ill_count = 0; } break; } } /* NOT REACHED */ } /* * Emergency interrupt polling thread. The thread begins execution * outside a critical section with the BGL held. * * If emergency interrupt polling is enabled, this thread will * execute all system interrupts not marked INTR_NOPOLL at the * specified polling frequency. * * WARNING! This thread runs *ALL* interrupt service routines that * are not marked INTR_NOPOLL, which basically means everything except * the 8254 clock interrupt and the ATA interrupt. It has very high * overhead and should only be used in situations where the machine * cannot otherwise be made to work. Due to the severe performance * degredation, it should not be enabled on production machines. */ static void ithread_emergency(void *arg __unused) { globaldata_t gd = mycpu; struct intr_info *info; intrec_t rec, nrec; int intr, cpuid = mycpuid; TD_INVARIANTS_DECLARE; get_mplock(); crit_enter_gd(gd); TD_INVARIANTS_GET(gd->gd_curthread); for (;;) { for (intr = 0; intr < max_installed_hard_intr[cpuid]; ++intr) { info = &intr_block->ary[cpuid][intr]; for (rec = info->i_reclist; rec; rec = nrec) { /* rec may be invalid after call */ nrec = rec->next; if ((rec->intr_flags & INTR_NOPOLL) == 0) { if (rec->serializer) { lwkt_serialize_handler_try(rec->serializer, rec->handler, rec->argument, NULL); } else { rec->handler(rec->argument, NULL); } TD_INVARIANTS_TEST(gd->gd_curthread, rec->name); } } } lwkt_deschedule_self(gd->gd_curthread); lwkt_switch(); } /* NOT REACHED */ } /* * Systimer callback - schedule the emergency interrupt poll thread * if emergency polling is enabled. */ static void emergency_intr_timer_callback(systimer_t info, int in_ipi __unused, struct intrframe *frame __unused) { if (emergency_intr_enable) lwkt_schedule(info->data); } /* * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. * The data for this machine dependent, and the declarations are in machine * dependent code. The layout of intrnames and intrcnt however is machine * independent. * * We do not know the length of intrcnt and intrnames at compile time, so * calculate things at run time. */ static int sysctl_intrnames(SYSCTL_HANDLER_ARGS) { struct intr_info *info; intrec_t rec; int error = 0; int len; int intr, cpuid; char buf[64]; for (cpuid = 0; cpuid < ncpus; ++cpuid) { for (intr = 0; error == 0 && intr < MAX_INTS; ++intr) { info = &intr_block->ary[cpuid][intr]; len = 0; buf[0] = 0; for (rec = info->i_reclist; rec; rec = rec->next) { ksnprintf(buf + len, sizeof(buf) - len, "%s%s", (len ? "/" : ""), rec->name); len += strlen(buf + len); } if (len == 0) { ksnprintf(buf, sizeof(buf), "irq%d", intr); len = strlen(buf); } error = SYSCTL_OUT(req, buf, len + 1); } } return (error); } SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, sysctl_intrnames, "", "Interrupt Names"); static int sysctl_intrcnt_all(SYSCTL_HANDLER_ARGS) { struct intr_info *info; int error = 0; int intr, cpuid; for (cpuid = 0; cpuid < ncpus; ++cpuid) { for (intr = 0; intr < MAX_INTS; ++intr) { info = &intr_block->ary[cpuid][intr]; error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count)); if (error) goto failed; } } failed: return(error); } SYSCTL_PROC(_hw, OID_AUTO, intrcnt_all, CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, sysctl_intrcnt_all, "", "Interrupt Counts"); SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, sysctl_intrcnt_all, "", "Interrupt Counts"); static void int_moveto_destcpu(int *orig_cpuid0, int cpuid) { int orig_cpuid = mycpuid; if (cpuid != orig_cpuid) lwkt_migratecpu(cpuid); *orig_cpuid0 = orig_cpuid; } static void int_moveto_origcpu(int orig_cpuid, int cpuid) { if (cpuid != orig_cpuid) lwkt_migratecpu(orig_cpuid); } static void intr_init(void *dummy __unused) { int cpuid; kprintf("Initialize MI interrupts for %d cpus\n", ncpus); intr_block = kmalloc(offsetof(struct intr_info_block, ary[ncpus][0]), M_INTRMNG, M_INTWAIT | M_ZERO); for (cpuid = 0; cpuid < ncpus; ++cpuid) { int intr; for (intr = 0; intr < MAX_INTS; ++intr) { struct intr_info *info = &intr_block->ary[cpuid][intr]; info->i_cpuid = cpuid; info->i_intr = intr; } } } SYSINIT(intr_init, SI_BOOT2_FINISH_PIC, SI_ORDER_ANY, intr_init, NULL);