Rework the interrupt code, shaving some cycles off in the process.

Rather than an "iointr" routine that decomposes a vector into an
IRQ, we maintain a vector table directly, hooking up each "iointr"
routine at the correct vector. This also allows us to hook device
interrupts up to specific vectors.

From thorpej NetBSD

Tested by myself and a number of end-users.

2 files changed, 40 insertions, 5 deletions

diff --git a/sys/arch/alpha/include/cpuconf.h b/sys/arch/alpha/include/cpuconf.h
index 565f03dcd0a..cd3e9f5103a 100644
--- a/sys/arch/alpha/include/cpuconf.h
+++ b/sys/arch/alpha/include/cpuconf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpuconf.h,v 1.4 2000/11/08 21:27:18 ericj Exp $	*/
+/*	$OpenBSD: cpuconf.h,v 1.5 2006/06/15 20:08:29 brad Exp $	*/
 /*	$NetBSD: cpuconf.h,v 1.12 2000/06/08 03:10:06 thorpej Exp $	*/
 
 /*
@@ -62,13 +62,11 @@ struct platform {
 	 * Platform Specific Function Hooks
 	 *	cons_init 	-	console initialization
 	 *	device_register	-	boot configuration aid
-	 *	iointr		-	I/O interrupt handler
 	 *	clockintr	-	Clock Interrupt Handler
 	 *	mcheck_handler	-	Platform Specific Machine Check Handler
 	 */
 	void	(*cons_init)(void);
 	void	(*device_register)(struct device *, void *);
-	void	(*iointr)(void *, unsigned long);
 	void	(*clockintr)(struct clockframe *);
 	void	(*mcheck_handler)(unsigned long, struct trapframe *,
 		    unsigned long, unsigned long);
diff --git a/sys/arch/alpha/include/intr.h b/sys/arch/alpha/include/intr.h
index 5576f4bcc6e..5fb16d23e34 100644
--- a/sys/arch/alpha/include/intr.h
+++ b/sys/arch/alpha/include/intr.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: intr.h,v 1.22 2006/03/12 03:14:36 brad Exp $ */
+/* $OpenBSD: intr.h,v 1.23 2006/06/15 20:08:29 brad Exp $ */
 /* $NetBSD: intr.h,v 1.26 2000/06/03 20:47:41 thorpej Exp $ */
 
 /*-
@@ -74,6 +74,34 @@
 #include <machine/atomic.h>
 
 /*
+ * The Alpha System Control Block.  This is 8k long, and you get
+ * 16 bytes per vector (i.e. the vector numbers are spaced 16
+ * apart).
+ *
+ * This is sort of a "shadow" SCB -- rather than the CPU jumping
+ * to (SCBaddr + (16 * vector)), like it does on the VAX, we get
+ * a vector number in a1.  We use the SCB to look up a routine/arg
+ * and jump to it.
+ *
+ * Since we use the SCB only for I/O interrupts, we make it shorter
+ * than normal, starting it at vector 0x800 (the start of the I/O
+ * interrupt vectors).
+ */
+#define	SCB_IOVECBASE	0x0800
+#define	SCB_VECSIZE	0x0010
+#define	SCB_SIZE	0x2000
+
+#define	SCB_VECTOIDX(x)	((x) >> 4)
+#define	SCB_IDXTOVEC(x)	((x) << 4)
+
+#define	SCB_NIOVECS	SCB_VECTOIDX(SCB_SIZE - SCB_IOVECBASE)
+
+struct scbvec { 
+	void	(*scb_func)(void *, u_long);
+	void	*scb_arg;
+};
+
+/*
  * Alpha interrupts come in at one of 4 levels:
  *
  *	software interrupt level
@@ -237,6 +265,8 @@ int	alpha_shared_intr_get_sharetype(struct alpha_shared_intr *,
 	    unsigned int);
 int	alpha_shared_intr_isactive(struct alpha_shared_intr *,
 	    unsigned int);
+int	alpha_shared_intr_firstactive(struct alpha_shared_intr *,
+	    unsigned int);
 void	alpha_shared_intr_set_dfltsharetype(struct alpha_shared_intr *,
 	    unsigned int, int);
 void	alpha_shared_intr_set_maxstrays(struct alpha_shared_intr *,
@@ -250,7 +280,14 @@ void	alpha_shared_intr_set_private(struct alpha_shared_intr *,
 void	*alpha_shared_intr_get_private(struct alpha_shared_intr *,
 	    unsigned int);
 
-void	set_iointr(void (*)(void *, unsigned long));
+extern struct scbvec scb_iovectab[];
+
+void	scb_init(void);
+void	scb_set(u_long, void (*)(void *, u_long), void *);
+u_long	scb_alloc(void (*)(void *, u_long), void *);
+void	scb_free(u_long);
+
+#define	SCB_ALLOC_FAILED	((u_long) -1)
 
 #endif /* _KERNEL */
 #endif /* ! _ALPHA_INTR_H_ */