From b701be7c869038ae880e038252a3c75d78f5986b Mon Sep 17 00:00:00 2001
From: thorpej <thorpej@NetBSD.org>
Date: Tue, 10 Aug 1999 18:53:03 +0000
Subject: [PATCH] Use atomic operations to manipulate the SSIR, and fix a
 problem introduced with the spllowersoftclock() changes where more interrupts
 than necessary were blocked while software interrupts were being processed.

---
 sys/arch/alpha/alpha/machdep.c | 19 ++++++++-----------
 sys/arch/alpha/include/intr.h  | 10 ++++++----
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/sys/arch/alpha/alpha/machdep.c b/sys/arch/alpha/alpha/machdep.c
index 73f412362e22..0ac7333770c9 100644
--- a/sys/arch/alpha/alpha/machdep.c
+++ b/sys/arch/alpha/alpha/machdep.c
@@ -1,4 +1,4 @@
-/* $NetBSD: machdep.c,v 1.177 1999/06/29 07:21:30 ross Exp $ */
+/* $NetBSD: machdep.c,v 1.178 1999/08/10 18:53:03 thorpej Exp $ */
 
 /*-
  * Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
@@ -80,7 +80,7 @@
 
 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
 
-__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.177 1999/06/29 07:21:30 ross Exp $");
+__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.178 1999/08/10 18:53:03 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1939,12 +1939,7 @@ do_sir()
 {
 	u_int64_t n;
 
-	do {
-		(void)splhigh();
-		n = ssir;
-		ssir = 0;
-		splsoft();		/* don't recurse through spl0() */
-
+	while ((n = alpha_atomic_loadlatch_q(&ssir, 0)) != 0) {
 #define	COUNT_SOFT	uvmexp.softs++
 
 #define	DO_SIR(bit, fn)							\
@@ -1963,15 +1958,17 @@ do_sir()
 
 #undef COUNT_SOFT
 #undef DO_SIR
-	} while (ssir != 0);
+	}
 }
 
 int
 spl0()
 {
 
-	if (ssir)
-		do_sir();		/* it lowers the IPL itself */
+	if (ssir) {
+		(void) alpha_pal_swpipl(ALPHA_PSL_IPL_SOFT);
+		do_sir();
+	}
 
 	return (alpha_pal_swpipl(ALPHA_PSL_IPL_0));
 }
diff --git a/sys/arch/alpha/include/intr.h b/sys/arch/alpha/include/intr.h
index a15135dc154d..b95ba8903187 100644
--- a/sys/arch/alpha/include/intr.h
+++ b/sys/arch/alpha/include/intr.h
@@ -1,4 +1,4 @@
-/* $NetBSD: intr.h,v 1.20 1999/08/05 18:08:08 thorpej Exp $ */
+/* $NetBSD: intr.h,v 1.21 1999/08/10 18:53:03 thorpej Exp $ */
 
 /*
  * Copyright (c) 1997 Christopher G. Demetriou.  All rights reserved.
@@ -87,9 +87,11 @@ extern u_int64_t ssir;
 #define	SIR_CLOCK	0x2
 #define	SIR_SERIAL	0x4
 
-#define	setsoftnet()	ssir |= SIR_NET
-#define	setsoftclock()	ssir |= SIR_CLOCK
-#define	setsoftserial()	ssir |= SIR_SERIAL
+#define	setsoft(x)	alpha_atomic_setbits_q(&ssir, (x))
+
+#define	setsoftnet()	setsoft(SIR_NET)
+#define	setsoftclock()	setsoft(SIR_CLOCK)
+#define	setsoftserial()	setsoft(SIR_SERIAL)
 
 /*
  * Interprocessor interrupts.  In order how we want them processed.