----------------------------------------------------------------------
r14917:  kmacy | 2008-04-12 01:46:54 -0700

fix WITNESS panic by converting intr_table_lock to sx lock and breaking spin lock out in to a separate lock
----------------------------------------------------------------------
=== local/IPSO_Oplin_integration/sys/i386/i386/intr_machdep.c
==================================================================
--- local/IPSO_Oplin_integration/sys/i386/i386/intr_machdep.c	(revision 14916)
+++ local/IPSO_Oplin_integration/sys/i386/i386/intr_machdep.c	(revision 14917)
@@ -48,6 +48,7 @@
 #include <sys/ktr.h>
 #include <sys/kernel.h>
 #include <sys/mutex.h>
+#include <sys/sx.h>
 #include <sys/proc.h>
 #include <sys/syslog.h>
 #include <sys/systm.h>
@@ -69,8 +70,9 @@
 
 static int intrcnt_index;
 static struct intsrc *interrupt_sources[NUM_IO_INTS];
-static struct mtx intr_table_lock;
+static struct sx intr_table_lock;
 static struct mtx intr_live_lock;
+static struct mtx intrcnt_lock;
 static STAILQ_HEAD(, pic) pics;
 
 #ifdef SMP
@@ -156,14 +158,14 @@
 {
 	int error;
 
-	mtx_lock_spin(&intr_table_lock);
+	sx_xlock(&intr_table_lock);
 	if (intr_pic_registered(pic))
 		error = EBUSY;
 	else {
 		STAILQ_INSERT_TAIL(&pics, pic, pics);
 		error = 0;
 	}
-	mtx_unlock_spin(&intr_table_lock);
+	sx_xunlock(&intr_table_lock);
 	return (error);
 }
 
@@ -185,16 +187,16 @@
 	    (mask_fn)isrc->is_pic->pic_enable_source, "irq%d:", vector);
 	if (error)
 		return (error);
-	mtx_lock_spin(&intr_table_lock);
+	sx_xlock(&intr_table_lock);
 	if (interrupt_sources[vector] != NULL) {
-		mtx_unlock_spin(&intr_table_lock);
+		sx_xunlock(&intr_table_lock);
 		intr_event_destroy(isrc->is_event);
 		return (EEXIST);
 	}
 	intrcnt_register(isrc);
 	interrupt_sources[vector] = isrc;
 	isrc->is_enabled = 0;
-	mtx_unlock_spin(&intr_table_lock);
+	sx_xunlock(&intr_table_lock);
 	return (0);
 }
 
@@ -225,7 +227,7 @@
 		idx = vector >> INTR_IDX_SHIFT;
 		mask = 1 << (vector & INTR_BIT_MASK);
 
-		mtx_lock_spin(&intr_table_lock);
+		sx_xlock(&intr_table_lock);
 
 		if (flags & (INTR_TYPE_CLK | INTR_TYPE_TTY | INTR_DIRECT)) {
 			/*
@@ -247,10 +249,10 @@
 			if (assign_cpu)
 				intr_assign_next_cpu(isrc);
 #endif
-			mtx_unlock_spin(&intr_table_lock);
+			sx_xunlock(&intr_table_lock);
 			isrc->is_pic->pic_enable_intr(isrc);
 		} else
-			mtx_unlock_spin(&intr_table_lock);
+			sx_xunlock(&intr_table_lock);
 		isrc->is_pic->pic_enable_source(isrc);
 	}
 	return (error);
@@ -712,12 +714,12 @@
 {
 	struct pic *pic;
 
-	mtx_lock_spin(&intr_table_lock);
+	sx_xlock(&intr_table_lock);
 	STAILQ_FOREACH(pic, &pics, pics) {
 		if (pic->pic_resume != NULL)
 			pic->pic_resume(pic);
 	}
-	mtx_unlock_spin(&intr_table_lock);
+	sx_xunlock(&intr_table_lock);
 }
 
 void
@@ -725,12 +727,12 @@
 {
 	struct pic *pic;
 
-	mtx_lock_spin(&intr_table_lock);
+	sx_xlock(&intr_table_lock);
 	STAILQ_FOREACH(pic, &pics, pics) {
 		if (pic->pic_suspend != NULL)
 			pic->pic_suspend(pic);
 	}
-	mtx_unlock_spin(&intr_table_lock);
+	sx_xunlock(&intr_table_lock);
 }
 
 static void
@@ -755,6 +757,8 @@
 
 	/* mtx_assert(&intr_table_lock, MA_OWNED); */
 	KASSERT(is->is_event != NULL, ("%s: isrc with no event", __func__));
+
+	mtx_lock_spin(&intrcnt_lock);
 	is->is_index = intrcnt_index;
 	intrcnt_index += 2;
 	snprintf(straystr, MAXCOMLEN + 1, "stray irq%d",
@@ -763,17 +767,18 @@
 	is->is_count = &intrcnt[is->is_index];
 	intrcnt_setname(straystr, is->is_index + 1);
 	is->is_straycount = &intrcnt[is->is_index + 1];
+	mtx_unlock_spin(&intrcnt_lock);
 }
 
 void
 intrcnt_add(const char *name, u_long **countp)
 {
 
-	mtx_lock_spin(&intr_table_lock);
+	mtx_lock_spin(&intrcnt_lock);
 	*countp = &intrcnt[intrcnt_index];
 	intrcnt_setname(name, intrcnt_index);
 	intrcnt_index++;
-	mtx_unlock_spin(&intr_table_lock);
+	mtx_unlock_spin(&intrcnt_lock);
 }
 
 static void
@@ -784,8 +789,9 @@
 	intrcnt_setname("???", 0);
 	intrcnt_index = 1;
 	STAILQ_INIT(&pics);
-	mtx_init(&intr_table_lock, "intr table", NULL, MTX_SPIN);
+	sx_init(&intr_table_lock, "intr sources");
 	mtx_init(&intr_live_lock, "intr live", NULL, MTX_SPIN);
+	mtx_init(&intrcnt_lock, "intrcnt", NULL, MTX_SPIN);
 
 	for (idx = 0; idx < INTR_ARR_LEN; idx++) {
 		intr_live_mask_proto[idx] = ~0;
@@ -1149,14 +1155,14 @@
 		return;
 
 	/* Round-robin assign a CPU to each enabled source. */
-	mtx_lock_spin(&intr_table_lock);
+	sx_xlock(&intr_table_lock);
 	assign_cpu = 1;
 	for (i = 0; i < NUM_IO_INTS; i++) {
 		isrc = interrupt_sources[i];
 		if (isrc != NULL && isrc->is_enabled)
 			intr_assign_next_cpu(isrc);
 	}
-	mtx_unlock_spin(&intr_table_lock);
+	sx_xunlock(&intr_table_lock);
 }
 SYSINIT(intr_shuffle_irqs, SI_SUB_SMP, SI_ORDER_SECOND, intr_shuffle_irqs, NULL)
 #endif