clockintr: add clockqueue_intrclock_install()

At some point, clockintr_cpu_init() is going to go away.  However,
there will still need to be a way to add an intrclock to a struct
clockintr_queue.

Add a new internal interface, clockqueue_intrclock_install().  If the
given clockintr_queue does not yet have an intrclock installed, it
copies the contents of the given intrclock to the clockintr_queue's
private intrclock (cq_intrclock) and sets CQ_INTRCLOCK in cq_flags.

I'm using the verb "install" here instead of "attach" because an
intrclock is really just a vtable that we copy into the
clockintr_queue.  The original intrclock is in no way "bound" or
"affixed" to a particular clockintr_queue: it's more akin to a stamp
that can be reused to initialize any number of individual
clockintr_queue structs.

diff --git a/sys/kern/kern_clockintr.c b/sys/kern/kern_clockintr.c
index 48fb0de..1f234f1 100644 (file)
--- a/sys/kern/kern_clockintr.c
+++ b/sys/kern/kern_clockintr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kern_clockintr.c,v 1.32 2023/08/21 17:22:04 cheloha Exp $ */
+/* $OpenBSD: kern_clockintr.c,v 1.33 2023/08/26 22:21:00 cheloha Exp $ */
 /*
  * Copyright (c) 2003 Dale Rahn <drahn@openbsd.org>
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -49,6 +49,8 @@ uint64_t clockintr_nsecuptime(const struct clockintr *);
 void clockintr_schedule(struct clockintr *, uint64_t);
 void clockintr_schedule_locked(struct clockintr *, uint64_t);
 void clockintr_statclock(struct clockintr *, void *);
+void clockqueue_intrclock_install(struct clockintr_queue *,
+    const struct intrclock *);
 uint64_t clockqueue_next(const struct clockintr_queue *);
 void clockqueue_reset_intrclock(struct clockintr_queue *);
 uint64_t nsec_advance(uint64_t *, uint64_t, uint64_t);
@@ -106,10 +108,8 @@ clockintr_cpu_init(const struct intrclock *ic)
 
        KASSERT(ISSET(clockintr_flags, CL_INIT));
 
-       if (ic != NULL && !ISSET(cq->cq_flags, CQ_INTRCLOCK)) {
-               cq->cq_intrclock = *ic;
-               SET(cq->cq_flags, CQ_INTRCLOCK);
-       }
+       if (ic != NULL)
+               clockqueue_intrclock_install(cq, ic);
 
        /* TODO: Remove these from struct clockintr_queue. */
        if (cq->cq_hardclock == NULL) {
@@ -533,6 +533,18 @@ clockqueue_init(struct clockintr_queue *cq)
        SET(cq->cq_flags, CQ_INIT);
 }
 
+void
+clockqueue_intrclock_install(struct clockintr_queue *cq,
+    const struct intrclock *ic)
+{
+       mtx_enter(&cq->cq_mtx);
+       if (!ISSET(cq->cq_flags, CQ_INTRCLOCK)) {
+               cq->cq_intrclock = *ic;
+               SET(cq->cq_flags, CQ_INTRCLOCK);
+       }
+       mtx_leave(&cq->cq_mtx);
+}
+
 uint64_t
 clockqueue_next(const struct clockintr_queue *cq)
 {