Implement a mechanism to establish interrupt handlers that don't grab the

kernel lock upon entry through a new IPL_MPSAFE flag/level.

ok mikeb@, mpi@

3 files changed, 18 insertions, 7 deletions

diff --git a/sys/arch/amd64/amd64/intr.c b/sys/arch/amd64/amd64/intr.c
index 6175d7de464..f5958ded7c9 100644
--- a/sys/arch/amd64/amd64/intr.c
+++ b/sys/arch/amd64/amd64/intr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: intr.c,v 1.33 2013/05/12 14:15:31 ratchov Exp $	*/
+/*	$OpenBSD: intr.c,v 1.34 2013/05/16 16:20:00 kettenis Exp $	*/
 /*	$NetBSD: intr.c,v 1.3 2003/03/03 22:16:20 fvdl Exp $	*/
 
 /*
@@ -343,6 +343,7 @@ intr_establish(int legacy_irq, struct pic *pic, int pin, int type, int level,
 	int slot, error, idt_vec;
 	struct intrsource *source;
 	struct intrstub *stubp;
+	int flags;
 
 #ifdef DIAGNOSTIC
 	if (legacy_irq != -1 && (legacy_irq < 0 || legacy_irq > 15))
@@ -352,6 +353,9 @@ intr_establish(int legacy_irq, struct pic *pic, int pin, int type, int level,
 		panic("intr_establish: non-legacy IRQ on i8259");
 #endif
 
+	flags = level & IPL_MPSAFE;
+	level &= ~IPL_MPSAFE;
+
 	error = intr_allocate_slot(pic, legacy_irq, pin, level, &ci, &slot,
 	    &idt_vec);
 	if (error != 0) {
@@ -426,6 +430,7 @@ intr_establish(int legacy_irq, struct pic *pic, int pin, int type, int level,
 	ih->ih_arg = arg;
 	ih->ih_next = *p;
 	ih->ih_level = level;
+	ih->ih_flags = flags; 
 	ih->ih_pin = pin;
 	ih->ih_cpu = ci;
 	ih->ih_slot = slot;
@@ -530,7 +535,10 @@ intr_handler(struct intrframe *frame, struct intrhand *ih)
 #ifdef MULTIPROCESSOR
 	int need_lock;
 
-	need_lock = frame->if_ppl < IPL_SCHED;
+	if (ih->ih_flags & IPL_MPSAFE)
+		need_lock = 0;
+	else
+		need_lock = frame->if_ppl < IPL_SCHED;
 
 	if (need_lock)
 		__mp_lock(&kernel_lock);
diff --git a/sys/arch/amd64/include/intr.h b/sys/arch/amd64/include/intr.h
index a4f6674f12e..e6532369e5c 100644
--- a/sys/arch/amd64/include/intr.h
+++ b/sys/arch/amd64/include/intr.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: intr.h,v 1.24 2013/05/12 14:15:31 ratchov Exp $	*/
+/*	$OpenBSD: intr.h,v 1.25 2013/05/16 16:20:00 kettenis Exp $	*/
 /*	$NetBSD: intr.h,v 1.2 2003/05/04 22:01:56 fvdl Exp $	*/
 
 /*-
@@ -92,6 +92,7 @@ struct intrhand {
 	int	(*ih_fun)(void *);
 	void	*ih_arg;
 	int	ih_level;
+	int	ih_flags;
 	struct	intrhand *ih_next;
 	int	ih_pin;
 	int	ih_slot;
diff --git a/sys/arch/amd64/include/intrdefs.h b/sys/arch/amd64/include/intrdefs.h
index 2ac495d5761..0d76886cc95 100644
--- a/sys/arch/amd64/include/intrdefs.h
+++ b/sys/arch/amd64/include/intrdefs.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: intrdefs.h,v 1.9 2011/06/16 19:46:40 kettenis Exp $	*/
+/*	$OpenBSD: intrdefs.h,v 1.10 2013/05/16 16:20:00 kettenis Exp $	*/
 /*	$NetBSD: intrdefs.h,v 1.2 2003/05/04 22:01:56 fvdl Exp $	*/
 
 #ifndef _AMD64_INTRDEFS_H
@@ -28,12 +28,14 @@
 #define	IPL_VM		0xa	/* memory allocation */
 #define	IPL_AUDIO	0xb	/* audio */
 #define	IPL_CLOCK	0xc	/* clock */
-#define IPL_SCHED	IPL_CLOCK
-#define IPL_STATCLOCK	IPL_CLOCK
+#define	IPL_SCHED	IPL_CLOCK
+#define	IPL_STATCLOCK	IPL_CLOCK
 #define	IPL_HIGH	0xd	/* everything */
-#define IPL_IPI		0xe	/* inter-processor interrupts */
+#define	IPL_IPI		0xe	/* inter-processor interrupts */
 #define	NIPL		16
 
+#define	IPL_MPSAFE	0x100
+
 /* Interrupt sharing types. */
 #define	IST_NONE	0	/* none */
 #define	IST_PULSE	1	/* pulsed */