When registering VME interrupts, maintain a direct ipl->vector table, as long

as no more than one interrupt is registered for a given level.

Then, if the VME interrupt vector reading cycle fails on the 188 interrupt
arbiter, we can use this table as a hint if it has a valid entry, since
we know on which ipl line the interrupt occured.

This basically silences the
m188_ext_int: timeout getting VME interrupt vector, level 3, mask 0x400<IRQ3>
occasional messages appearing when the MVME376 is overloaded.

3 files changed, 57 insertions, 11 deletions

diff --git a/sys/arch/mvme88k/dev/vme.c b/sys/arch/mvme88k/dev/vme.c
index ded1048ada3..b50ba20db04 100644
--- a/sys/arch/mvme88k/dev/vme.c
+++ b/sys/arch/mvme88k/dev/vme.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vme.c,v 1.45 2006/11/16 23:21:56 miod Exp $ */
+/*	$OpenBSD: vme.c,v 1.46 2007/03/22 18:52:38 miod Exp $ */
 /*
  * Copyright (c) 2004, Miodrag Vallat.
  * Copyright (c) 1999 Steve Murphree, Jr.
@@ -431,6 +431,18 @@ vmerw(sc, uio, flags, bus)
 	return error;
 }
 
+#ifdef MVME188
+/*
+ * Currently registered VME interrupt vectors for a given IPL, if they
+ * are unique. Used to help the MVME188 interrupt handler when it's getting
+ * behind.
+ */
+u_int vmevec_hints[8] = {
+	(u_int)-1, (u_int)-1, (u_int)-1, (u_int)-1,
+	(u_int)-1, (u_int)-1, (u_int)-1, (u_int)-1
+};
+#endif
+
 /*
  * On the VMEbus, only one cpu may be configured to respond to any
  * particular vme ipl. Therefore, it wouldn't make sense to globally
@@ -448,6 +460,12 @@ int
 vmeintr_establish(int vec, struct intrhand *ih, const char *name)
 {
 	struct vmesoftc *sc = (struct vmesoftc *) vme_cd.cd_devs[0];
+	int rc;
+
+#ifdef DIAGNOSTIC
+	if (ih->ih_ipl < 1 || ih->ih_ipl > 7)
+		return (EINVAL);
+#endif
 
 	switch (vmebustype) {
 #if NPCCTWO > 0
@@ -459,7 +477,17 @@ vmeintr_establish(int vec, struct intrhand *ih, const char *name)
 #endif
 	}
 
-	return intr_establish(vec, ih, name);
+	if ((rc = intr_establish(vec, ih, name)) != 0)
+		return (rc);
+
+#ifdef MVME188
+	if (vmevec_hints[ih->ih_ipl] == (u_int)-1)
+		vmevec_hints[ih->ih_ipl] = vec;
+	else
+		vmevec_hints[ih->ih_ipl] = (u_int)-1;
+#endif
+
+	return (0);
 }
 
 #if NPCCTWO > 0
diff --git a/sys/arch/mvme88k/include/cpu.h b/sys/arch/mvme88k/include/cpu.h
index fdf59bb1744..0ae4bdd0425 100644
--- a/sys/arch/mvme88k/include/cpu.h
+++ b/sys/arch/mvme88k/include/cpu.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpu.h,v 1.35 2006/05/13 16:05:50 miod Exp $ */
+/* $OpenBSD: cpu.h,v 1.36 2007/03/22 18:52:39 miod Exp $ */
 /*
  * Copyright (c) 1996 Nivas Madhur
  * Copyright (c) 1992, 1993
@@ -75,6 +75,15 @@ int	intr_findvec(int, int, int);
 typedef SLIST_HEAD(, intrhand) intrhand_t;
 extern intrhand_t intr_handlers[NVMEINTR];
 
+#ifdef MVME188
+/*
+ * Currently registered VME interrupt vectors for a given IPL, if they
+ * are unique. Used to help the MVME188 interrupt handler when it's getting
+ * behind.
+ */
+extern u_int vmevec_hints[8];
+#endif
+
 void	doboot(void);
 void	nmihand(void *);
 
diff --git a/sys/arch/mvme88k/mvme88k/m188_machdep.c b/sys/arch/mvme88k/mvme88k/m188_machdep.c
index 0054975cfe2..a23cb78938a 100644
--- a/sys/arch/mvme88k/mvme88k/m188_machdep.c
+++ b/sys/arch/mvme88k/mvme88k/m188_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: m188_machdep.c,v 1.24 2006/11/20 21:51:33 miod Exp $	*/
+/*	$OpenBSD: m188_machdep.c,v 1.25 2007/03/22 18:52:39 miod Exp $	*/
 /*
  * Copyright (c) 1998, 1999, 2000, 2001 Steve Murphree, Jr.
  * Copyright (c) 1996 Nivas Madhur
@@ -478,13 +478,22 @@ m188_ext_int(u_int v, struct trapframe *eframe)
 
 				 */
 				{
-					printf("%s: timeout getting VME "
-					    "interrupt vector, "
-					    "level %d, mask 0x%b\n",
-					    __func__, level,
-					   cur_mask, IST_STRING); 
-					ign_mask |=  1 << intbit;
-					continue;
+					/*
+					 * If only one VME interrupt is
+					 * registered with this IPL,
+					 * we can reasonably safely
+					 * assume that this is our vector.
+					 */
+					vec = vmevec_hints[level];
+					if (vec == (u_int)-1) {
+						printf("%s: timeout getting VME"
+						    " interrupt vector, "
+						    "level %d, mask 0x%b\n",
+						    __func__, level,
+						   cur_mask, IST_STRING); 
+						ign_mask |=  1 << intbit;
+						continue;
+					}
 				}
 			}
 			if (vec == 0) {