/* * 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. * * $FreeBSD$ * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* prototype for legacy_setsoftnet */ struct int_entropy { struct proc *proc; int vector; }; void *net_ih; void *vm_ih; void *softclock_ih; struct ithd *clk_ithd; struct ithd *tty_ithd; static struct mtx ithread_list_lock; static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); static void ithread_update(struct ithd *); static void ithread_loop(void *); static void ithread_init(void *); static void start_softintr(void *); static void swi_net(void *); u_char ithread_priority(enum intr_type flags) { u_char pri; flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK); switch (flags) { case INTR_TYPE_TTY: pri = PI_TTYLOW; break; case INTR_TYPE_BIO: /* * XXX We need to refine this. BSD/OS distinguishes * between tape and disk priorities. */ pri = PI_DISK; break; case INTR_TYPE_NET: pri = PI_NET; break; case INTR_TYPE_CAM: pri = PI_DISK; /* XXX or PI_CAM? */ break; case INTR_TYPE_CLK: pri = PI_REALTIME; break; case INTR_TYPE_MISC: pri = PI_DULL; /* don't care */ break; default: /* We didn't specify an interrupt level. */ panic("ithread_priority: no interrupt type in flags"); } return pri; } /* * Regenerate the name (p_comm) and priority for a threaded interrupt thread. */ static void ithread_update(struct ithd *ithd) { struct intrhand *ih; struct proc *p; int entropy; p = ithd->it_proc; if (p == NULL) return; strncpy(p->p_comm, ithd->it_name, sizeof(ithd->it_name)); ih = TAILQ_FIRST(&ithd->it_handlers); if (ih == NULL) { p->p_pri.pri_level = PRI_MAX_ITHD; ithd->it_flags &= ~IT_ENTROPY; return; } entropy = 0; p->p_pri.pri_level = ih->ih_pri; TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) { if (strlen(p->p_comm) + strlen(ih->ih_name) + 1 < sizeof(p->p_comm)) { strcat(p->p_comm, " "); strcat(p->p_comm, ih->ih_name); } else if (strlen(p->p_comm) + 1 == sizeof(p->p_comm)) { if (p->p_comm[sizeof(p->p_comm) - 2] == '+') p->p_comm[sizeof(p->p_comm) - 2] = '*'; else p->p_comm[sizeof(p->p_comm) - 2] = '+'; } else strcat(p->p_comm, "+"); if (ih->ih_flags & IH_ENTROPY) entropy++; } if (entropy) ithd->it_flags |= IT_ENTROPY; else ithd->it_flags &= ~IT_ENTROPY; } int ithread_create(struct ithd **ithread, int vector, int flags, void (*disable)(int), void (*enable)(int), const char *fmt, ...) { struct ithd *ithd; struct proc *p; int error; va_list ap; /* The only valid flag during creation is IT_SOFT. */ if ((flags & ~IT_SOFT) != 0) return (EINVAL); ithd = malloc(sizeof(struct ithd), M_ITHREAD, M_WAITOK | M_ZERO); ithd->it_vector = vector; ithd->it_disable = disable; ithd->it_enable = enable; ithd->it_flags = flags; TAILQ_INIT(&ithd->it_handlers); va_start(ap, fmt); vsnprintf(ithd->it_name, sizeof(ithd->it_name), fmt, ap); va_end(ap); error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID, ithd->it_name); if (error) { free(ithd, M_ITHREAD); return (error); } p->p_pri.pri_class = PRI_ITHD; p->p_pri.pri_level = PRI_MAX_ITHD; p->p_stat = SWAIT; ithd->it_proc = p; p->p_ithd = ithd; if (ithread != NULL) *ithread = ithd; return (0); } int ithread_destroy(struct ithd *ithread) { if (ithread == NULL || !TAILQ_EMPTY(&ithread->it_handlers)) return (EINVAL); mtx_lock_spin(&sched_lock); ithread->it_flags |= IT_DEAD; if (ithread->it_proc->p_stat == SWAIT) { ithread->it_proc->p_stat = SRUN; setrunqueue(ithread->it_proc); } mtx_unlock_spin(&sched_lock); return (0); } int ithread_add_handler(struct ithd* ithread, const char *name, driver_intr_t handler, void *arg, u_char pri, enum intr_type flags, void **cookiep) { struct intrhand *ih, *temp_ih; if (ithread == NULL || name == NULL || handler == NULL) return (EINVAL); if ((flags & INTR_FAST) !=0) flags |= INTR_EXCL; ih = malloc(sizeof(struct intrhand), M_ITHREAD, M_WAITOK | M_ZERO); ih->ih_handler = handler; ih->ih_argument = arg; ih->ih_name = name; ih->ih_ithread = ithread; ih->ih_pri = pri; if (flags & INTR_FAST) ih->ih_flags = IH_FAST | IH_EXCLUSIVE; else if (flags & INTR_EXCL) ih->ih_flags = IH_EXCLUSIVE; if (flags & INTR_MPSAFE) ih->ih_flags |= IH_MPSAFE; if (flags & INTR_ENTROPY) ih->ih_flags |= IH_ENTROPY; mtx_lock_spin(&ithread_list_lock); if ((flags & INTR_EXCL) !=0 && !TAILQ_EMPTY(&ithread->it_handlers)) goto fail; if (!TAILQ_EMPTY(&ithread->it_handlers) && (TAILQ_FIRST(&ithread->it_handlers)->ih_flags & IH_EXCLUSIVE) != 0) goto fail; TAILQ_FOREACH(temp_ih, &ithread->it_handlers, ih_next) if (temp_ih->ih_pri > ih->ih_pri) break; if (temp_ih == NULL) TAILQ_INSERT_TAIL(&ithread->it_handlers, ih, ih_next); else TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); ithread_update(ithread); mtx_unlock_spin(&ithread_list_lock); if (cookiep != NULL) *cookiep = ih; return (0); fail: mtx_unlock_spin(&ithread_list_lock); free(ih, M_ITHREAD); return (EINVAL); } int ithread_remove_handler(void *cookie) { struct intrhand *handler = (struct intrhand *)cookie; struct ithd *ithread; #ifdef INVARIANTS struct intrhand *ih; #endif if (handler == NULL) return (EINVAL); ithread = handler->ih_ithread; KASSERT(ithread != NULL, ("interrupt handler \"%s\" has a NULL interrupt thread", handler->ih_name)); mtx_lock_spin(&ithread_list_lock); #ifdef INVARIANTS TAILQ_FOREACH(ih, &ithread->it_handlers, ih_next) if (ih == handler) goto ok; mtx_unlock_spin(&ithread_list_lock); panic("interrupt handler \"%s\" not found in interrupt thread \"%s\"", ih->ih_name, ithread->it_name); ok: #endif TAILQ_REMOVE(&ithread->it_handlers, handler, ih_next); ithread_update(ithread); mtx_unlock_spin(&ithread_list_lock); free(handler, M_ITHREAD); return (0); } int ithread_schedule(struct ithd *ithread, int do_switch) { struct int_entropy entropy; struct proc *p; intrmask_t saveintr; /* * If no ithread or no handlers, then we have a stray interrupt. */ if ((ithread == NULL) || TAILQ_EMPTY(&ithread->it_handlers)) return (EINVAL); /* * If any of the handlers for this ithread claim to be good * sources of entropy, then gather some. */ if (harvest.interrupt && ithread->it_flags & IT_ENTROPY) { entropy.vector = ithread->it_vector; entropy.proc = CURPROC; random_harvest(&entropy, sizeof(entropy), 2, 0, RANDOM_INTERRUPT); } p = ithread->it_proc; CTR3(KTR_INTR, __func__ ": pid %d: (%s) need = %d", p->p_pid, p->p_comm, ithread->it_need); /* * Set it_need to tell the thread to keep running if it is already * running. Then, grab sched_lock and see if we actually need to * put this thread on the runqueue. If so and the do_switch flag is * true, then switch to the ithread immediately. Otherwise, use * need_resched() to guarantee that this ithread will run before any * userland processes. */ ithread->it_need = 1; mtx_lock_spin(&sched_lock); if (p->p_stat == SWAIT) { CTR1(KTR_INTR, __func__ ": setrunqueue %d", p->p_pid); p->p_stat = SRUN; setrunqueue(p); if (do_switch) { saveintr = sched_lock.mtx_saveintr; mtx_intr_enable(&sched_lock); if (curproc != PCPU_GET(idleproc)) setrunqueue(curproc); curproc->p_stats->p_ru.ru_nvcsw++; mi_switch(); sched_lock.mtx_saveintr = saveintr; } else need_resched(); } else { CTR3(KTR_INTR, __func__ ": pid %d: it_need %d, state %d", p->p_pid, ithread->it_need, p->p_stat); } mtx_unlock_spin(&sched_lock); return (0); } int swi_add(struct ithd **ithdp, const char *name, driver_intr_t handler, void *arg, int pri, enum intr_type flags, void **cookiep) { struct ithd *ithd; int error; if (flags & (INTR_FAST | INTR_ENTROPY)) return (EINVAL); ithd = (ithdp != NULL) ? *ithdp : NULL; if (ithd != NULL) { if ((ithd->it_flags & IT_SOFT) == 0) return(EINVAL); } else { error = ithread_create(&ithd, pri, IT_SOFT, NULL, NULL, "swi%d:", pri); if (error) return (error); if (ithdp != NULL) *ithdp = ithd; } return (ithread_add_handler(ithd, name, handler, arg, (pri * RQ_PPQ) + PI_SOFT, flags, cookiep)); } /* * Schedule a heavyweight software interrupt process. */ void swi_sched(void *cookie, int flags) { struct intrhand *ih = (struct intrhand *)cookie; struct ithd *it = ih->ih_ithread; struct proc *p = it->it_proc; int error; atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */ CTR3(KTR_INTR, "swi_sched pid %d(%s) need=%d", p->p_pid, p->p_comm, it->it_need); /* * Set ih_need for this handler so that if the ithread is already * running it will execute this handler on the next pass. Otherwise, * it will execute it the next time it runs. */ atomic_store_rel_int(&ih->ih_need, 1); if (!(flags & SWI_DELAY)) { error = ithread_schedule(it, !cold && flags & SWI_SWITCH); KASSERT(error == 0, ("stray software interrupt")); } } /* * This is the main code for interrupt threads. */ void ithread_loop(void *arg) { struct ithd *ithd; /* our thread context */ struct intrhand *ih; /* and our interrupt handler chain */ struct proc *p; p = curproc; ithd = (struct ithd *)arg; /* point to myself */ KASSERT(ithd->it_proc == p && p->p_ithd == ithd, (__func__ ": ithread and proc linkage out of sync")); /* * As long as we have interrupts outstanding, go through the * list of handlers, giving each one a go at it. */ for (;;) { /* * If we are an orphaned thread, then just die. */ if (ithd->it_flags & IT_DEAD) { CTR2(KTR_INTR, __func__ ": pid %d: (%s) exiting", p->p_pid, p->p_comm); p->p_ithd = NULL; mtx_lock(&Giant); free(ithd, M_ITHREAD); kthread_exit(0); } CTR3(KTR_INTR, __func__ ": pid %d: (%s) need=%d", p->p_pid, p->p_comm, ithd->it_need); while (ithd->it_need) { /* * Service interrupts. If another interrupt * arrives while we are running, they will set * it_need to denote that we should make * another pass. */ atomic_store_rel_int(&ithd->it_need, 0); TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) { if (ithd->it_flags & IT_SOFT && !ih->ih_need) continue; atomic_store_rel_int(&ih->ih_need, 0); CTR5(KTR_INTR, __func__ ": pid %d ih=%p: %p(%p) flg=%x", p->p_pid, (void *)ih, (void *)ih->ih_handler, ih->ih_argument, ih->ih_flags); if ((ih->ih_flags & IH_MPSAFE) == 0) mtx_lock(&Giant); ih->ih_handler(ih->ih_argument); if ((ih->ih_flags & IH_MPSAFE) == 0) mtx_unlock(&Giant); } } /* * Processed all our interrupts. Now get the sched * lock. This may take a while and it_need may get * set again, so we have to check it again. */ mtx_assert(&Giant, MA_NOTOWNED); mtx_lock_spin(&sched_lock); if (!ithd->it_need) { /* * Should we call this earlier in the loop above? */ if (ithd->it_enable != NULL) ithd->it_enable(ithd->it_vector); p->p_stat = SWAIT; /* we're idle */ CTR1(KTR_INTR, __func__ ": pid %d: done", p->p_pid); mi_switch(); CTR1(KTR_INTR, __func__ ": pid %d: resumed", p->p_pid); } mtx_unlock_spin(&sched_lock); } } /* * Initialize mutex used to protect ithread handler lists. */ static void ithread_init(void *dummy) { mtx_init(&ithread_list_lock, "ithread list lock", MTX_SPIN); } SYSINIT(ithread_init, SI_SUB_INTR, SI_ORDER_FIRST, ithread_init, NULL); /* * Start standard software interrupt threads */ static void start_softintr(void *dummy) { if (swi_add(NULL, "net", swi_net, NULL, SWI_NET, 0, &net_ih) || swi_add(&clk_ithd, "clock", softclock, NULL, SWI_CLOCK, INTR_MPSAFE, &softclock_ih) || swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, 0, &vm_ih)) panic("died while creating standard software ithreads"); PROC_LOCK(clk_ithd->it_proc); clk_ithd->it_proc->p_flag |= P_NOLOAD; PROC_UNLOCK(clk_ithd->it_proc); } SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL) void legacy_setsoftnet(void) { swi_sched(net_ih, SWI_NOSWITCH); } /* * XXX: This should really be in the network code somewhere and installed * via a SI_SUB_SOFINTR, SI_ORDER_MIDDLE sysinit. */ void (*netisrs[32]) __P((void)); u_int netisr; int register_netisr(num, handler) int num; netisr_t *handler; { if (num < 0 || num >= (sizeof(netisrs)/sizeof(*netisrs)) ) { printf("register_netisr: bad isr number: %d\n", num); return (EINVAL); } netisrs[num] = handler; return (0); } int unregister_netisr(num) int num; { if (num < 0 || num >= (sizeof(netisrs)/sizeof(*netisrs)) ) { printf("unregister_netisr: bad isr number: %d\n", num); return (EINVAL); } netisrs[num] = NULL; return (0); } static void swi_net(void *dummy) { u_int bits; int i; bits = atomic_readandclear_int(&netisr); while ((i = ffs(bits)) != 0) { i--; if (netisrs[i] != NULL) netisrs[i](); else printf("swi_net: unregistered isr number: %d.\n", i); bits &= ~(1 << i); } }