Date: Thu, 30 Nov 2006 09:07:48 -0800 From: Marcel Moolenaar <xcllnt@mac.com> To: ppc@FreeBSD.org Subject: Please review: shared interrupts with fast handlers Message-ID: <E20D6528-5B1B-4F22-A36F-55ED676DA9F4@mac.com>
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All,
Attached a patch to support interrupt sharing with fast handlers. It's
pretty much copied from ia64. Please review.
With these changes, vmstat -i shows:
imac% vmstat -i
interrupt total rate
irq19: 102984 2
irq27: 3 0
irq28: 1 0
irq40: 1 0
irq41: 25400 0
Total 128389 2
I think this is the same as before, but can't really test right now.
It's not that informative though. It's probably nicer to see the
actual device name, as in:
imac% vmstat -i
interrupt total rate
irq19: 102984 2
ohci0: 3 0
ohci1: 1 0
fwohci0: 1 0
gem0: 25400 0
Total 128389 2
Did I changethe output of vmstat -i?
If not, should I do that?
Thanks,
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filename=intr_machdep.diff
Index: intr_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/powerpc/powerpc/intr_machdep.c,v
retrieving revision 1.8
diff -u -r1.8 intr_machdep.c
--- intr_machdep.c 2 Aug 2006 17:50:31 -0000 1.8
+++ intr_machdep.c 30 Nov 2006 04:48:40 -0000
@@ -66,6 +66,7 @@
#include <sys/queue.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
+#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
@@ -82,25 +83,18 @@
MALLOC_DEFINE(M_INTR, "intr", "interrupt handler data");
-static int intr_initialized = 0;
+struct ppc_intr {
+ struct intr_event *event;
+ long *cntp;
+};
+
+static struct mtx ppc_intrs_lock;
+static struct ppc_intr **ppc_intrs;
+static u_int ppc_nintrs;
-static u_int intr_nirq;
-static struct ppc_intr_handler *intr_handlers;
+static int intrcnt_index;
-static struct mtx intr_table_lock;
-
-extern int extint, extsize;
-extern u_long extint_call;
-
-static int intrcnt_index;
-static ih_func_t intr_stray_handler;
-static ih_func_t sched_ithd;
-
-static void (*irq_enable)(uintptr_t);
-static void (*irq_disable)(uintptr_t);
-
-static void intrcnt_setname(const char *name, int index);
-static void intrcnt_updatename(struct ppc_intr_handler *ih);
+static void (*irq_enable)(uintptr_t);
static void
intrcnt_setname(const char *name, int index)
@@ -109,85 +103,33 @@
MAXCOMLEN, name);
}
-static void
-intrcnt_updatename(struct ppc_intr_handler *ih)
-{
- intrcnt_setname(ih->ih_event->ie_fullname, ih->ih_index);
-}
-
-static void
-intrcnt_register(struct ppc_intr_handler *ih)
-{
- char straystr[MAXCOMLEN + 1];
-
- KASSERT(ih->ih_event != NULL,
- ("%s: ppc_intr_handler with no event", __func__));
-
- ih->ih_index = intrcnt_index;
- intrcnt_index += 2;
- snprintf(straystr, MAXCOMLEN + 1, "stray irq%d", ih->ih_irq);
- intrcnt_updatename(ih);
- ih->ih_count = &intrcnt[ih->ih_index];
- intrcnt_setname(straystr, ih->ih_index + 1);
- ih->ih_straycount = &intrcnt[ih->ih_index + 1];
-}
-
void
intr_init(void (*handler)(void), int nirq, void (*irq_e)(uintptr_t),
void (*irq_d)(uintptr_t))
{
- int i;
- u_int32_t msr;
-
- if (intr_initialized != 0)
- panic("intr_init: interrupts intialized twice\n");
+ static int initialized = 0;
+ uint32_t msr;
- intr_initialized++;
+ if (initialized)
+ panic("intr_init: interrupts initialized twice\n");
+ initialized++;
- intr_nirq = nirq;
- intr_handlers = malloc(nirq * sizeof(struct ppc_intr_handler), M_INTR,
+ ppc_nintrs = nirq;
+ ppc_intrs = malloc(nirq * sizeof(struct ppc_intr *), M_INTR,
M_NOWAIT|M_ZERO);
- if (intr_handlers == NULL)
+ if (ppc_intrs == NULL)
panic("intr_init: unable to allocate interrupt handler array");
- for (i = 0; i < nirq; i++) {
- intr_handlers[i].ih_func = intr_stray_handler;
- intr_handlers[i].ih_arg = &intr_handlers[i];
- intr_handlers[i].ih_irq = i;
- intr_handlers[i].ih_flags = 0;
- /* mux all initial stray irqs onto same count... */
- intr_handlers[i].ih_straycount = &intrcnt[0];
- }
+ mtx_init(&ppc_intrs_lock, "intr table", NULL, MTX_SPIN);
+
+ irq_enable = irq_e;
intrcnt_setname("???", 0);
intrcnt_index = 1;
msr = mfmsr();
mtmsr(msr & ~PSL_EE);
-
ext_intr_install(handler);
-
- mtmsr(msr);
-
- irq_enable = irq_e;
- irq_disable = irq_d;
-
- mtx_init(&intr_table_lock, "intr table", NULL, MTX_SPIN);
-}
-
-void
-intr_setup(u_int irq, ih_func_t *ihf, void *iha, u_int flags)
-{
- u_int32_t msr;
-
- msr = mfmsr();
- mtmsr(msr & ~PSL_EE);
-
- intr_handlers[irq].ih_func = ihf;
- intr_handlers[irq].ih_arg = iha;
- intr_handlers[irq].ih_irq = irq;
- intr_handlers[irq].ih_flags = flags;
-
mtmsr(msr);
}
@@ -195,122 +137,111 @@
inthand_add(const char *name, u_int irq, void (*handler)(void *), void *arg,
int flags, void **cookiep)
{
- struct ppc_intr_handler *ih;
- struct intr_event *event, *orphan;
- int error = 0;
- int created_event = 0;
+ struct ppc_intr *i, *orphan;
+ u_int idx;
+ int error;
/*
* Work around a race where more than one CPU may be registering
* handlers on the same IRQ at the same time.
*/
- ih = &intr_handlers[irq];
- mtx_lock_spin(&intr_table_lock);
- event = ih->ih_event;
- mtx_unlock_spin(&intr_table_lock);
- if (event == NULL) {
- error = intr_event_create(&event, (void *)irq, 0,
+ mtx_lock_spin(&ppc_intrs_lock);
+ i = ppc_intrs[irq];
+ mtx_unlock_spin(&ppc_intrs_lock);
+
+ if (i == NULL) {
+ i = malloc(sizeof(*i), M_INTR, M_NOWAIT);
+ if (i == NULL)
+ return (ENOMEM);
+ error = intr_event_create(&i->event, (void *)irq, 0,
(void (*)(void *))irq_enable, "irq%d:", irq);
- if (error)
+ if (error) {
+ free(i, M_INTR);
return (error);
+ }
- mtx_lock_spin(&intr_table_lock);
+ mtx_lock_spin(&ppc_intrs_lock);
+ if (ppc_intrs[irq] != NULL) {
+ orphan = i;
+ i = ppc_intrs[irq];
+ mtx_unlock_spin(&ppc_intrs_lock);
- if (ih->ih_event == NULL) {
- ih->ih_event = event;
- created_event++;
- mtx_unlock_spin(&intr_table_lock);
+ intr_event_destroy(orphan->event);
+ free(orphan, M_INTR);
} else {
- orphan = event;
- event = ih->ih_event;
- mtx_unlock_spin(&intr_table_lock);
- intr_event_destroy(orphan);
+ ppc_intrs[irq] = i;
+ idx = intrcnt_index++;
+ mtx_unlock_spin(&ppc_intrs_lock);
+
+ i->cntp = &intrcnt[idx];
+ intrcnt_setname(i->event->ie_fullname, idx);
}
}
- /* XXX: Should probably fix support for multiple FAST. */
- if (flags & INTR_FAST)
- flags |= INTR_EXCL;
- error = intr_event_add_handler(event, name, handler, arg,
+ error = intr_event_add_handler(i->event, name, handler, arg,
intr_priority(flags), flags, cookiep);
-
- if ((flags & INTR_FAST) == 0 || error)
- intr_setup(irq, sched_ithd, ih, flags);
-
- if (error)
- return (error);
-
- if (flags & INTR_FAST)
- intr_setup(irq, handler, arg, flags);
-
- intrcnt_register(ih);
-
- return (0);
+ return (error);
}
int
inthand_remove(u_int irq, void *cookie)
{
- struct ppc_intr_handler *ih;
- int error;
-
- error = intr_event_remove_handler(cookie);
- if (error == 0) {
- ih = &intr_handlers[irq];
-
- mtx_lock_spin(&intr_table_lock);
-
- if (ih->ih_event == NULL) {
- intr_setup(irq, intr_stray_handler, ih, 0);
- } else {
- intr_setup(irq, sched_ithd, ih, 0);
- }
-
- mtx_unlock_spin(&intr_table_lock);
- }
-
- return (error);
+ return (intr_event_remove_handler(cookie));
}
void
intr_handle(u_int irq)
{
- atomic_add_long(intr_handlers[irq].ih_count, 1);
- intr_handlers[irq].ih_func(intr_handlers[irq].ih_arg);
+ struct ppc_intr *i;
+ struct intr_event *ie;
+ struct intr_handler *ih;
+ int error, sched;
+
+ i = ppc_intrs[irq];
+ if (i == NULL)
+ goto stray;
- /* XXX wrong thing when using pre-emption ? */
- if ((intr_handlers[irq].ih_flags & INTR_FAST) != 0)
- irq_enable(irq);
-}
-
-static void
-intr_stray_handler(void *cookie)
-{
- struct ppc_intr_handler *ih;
+ atomic_add_long(i->cntp, 1);
- ih = (struct ppc_intr_handler *)cookie;
+ ie = i->event;
+ KASSERT(ie != NULL, ("%s: interrupt without an event", __func__));
- if (*intr_handlers[ih->ih_irq].ih_straycount < MAX_STRAY_LOG) {
- printf("stray irq %d\n", ih->ih_irq);
+ if (TAILQ_EMPTY(&ie->ie_handlers))
+ goto stray;
- atomic_add_long(intr_handlers[ih->ih_irq].ih_straycount, 1);
- if (*intr_handlers[ih->ih_irq].ih_straycount >= MAX_STRAY_LOG)
- printf("got %d stray irq %d's: not logging anymore\n",
- MAX_STRAY_LOG, ih->ih_irq);
+ /*
+ * Execute all fast interrupt handlers directly without Giant. Note
+ * that this means that any fast interrupt handler must be MP safe.
+ */
+ sched = 0;
+ critical_enter();
+ TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
+ if (!(ih->ih_flags & IH_FAST)) {
+ sched = 1;
+ continue;
+ }
+ CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
+ ih->ih_handler, ih->ih_argument, ih->ih_name);
+ ih->ih_handler(ih->ih_argument);
}
-}
-
-static void
-sched_ithd(void *cookie)
-{
- struct ppc_intr_handler *ih;
- int error;
+ critical_exit();
- ih = (struct ppc_intr_handler *)cookie;
-
- error = intr_event_schedule_thread(ih->ih_event);
+ if (sched) {
+ error = intr_event_schedule_thread(ie);
+ KASSERT(error == 0, ("%s: impossible stray interrupt",
+ __func__));
+ } else
+ irq_enable(irq);
+ return;
- if (error == EINVAL)
- intr_stray_handler(ih);
+stray:
+ atomic_add_long(&intrcnt[0], 1);
+ if (intrcnt[0] <= MAX_STRAY_LOG) {
+ printf("stray irq %d\n", irq);
+ if (intrcnt[0] >= MAX_STRAY_LOG) {
+ printf("got %d stray interrupts, not logging anymore\n",
+ MAX_STRAY_LOG);
+ }
+ }
}
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--
Marcel Moolenaar
xcllnt@mac.com
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