From: miod <miod@openbsd.org>
Date: Tue, 16 Dec 2014 21:29:05 +0000 (+0000)
Subject: Do not grab the kernel lock for clock interrupts, hardclock() will behave
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=57a1818078bf9021589898333d9352010285fe1c;p=openbsd

Do not grab the kernel lock for clock interrupts, hardclock() will behave
correctly without. Modeled after sparc64 logic.
---

diff --git a/sys/arch/aviion/aviion/av530_machdep.c b/sys/arch/aviion/aviion/av530_machdep.c
index 381728da556..8e7e1433a33 100644
--- a/sys/arch/aviion/aviion/av530_machdep.c
+++ b/sys/arch/aviion/aviion/av530_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: av530_machdep.c,v 1.13 2014/11/16 12:30:56 deraadt Exp $	*/
+/*	$OpenBSD: av530_machdep.c,v 1.14 2014/12/16 21:29:05 miod Exp $	*/
 /*
  * Copyright (c) 2006, 2007, 2010 Miodrag Vallat.
  *
@@ -570,6 +570,9 @@ av530_intr(struct trapframe *eframe)
 #ifdef DIAGNOSTIC
 	static int problems = 0;
 #endif
+#ifdef MULTIPROCESSOR
+	int need_lock;
+#endif
 
 	cur_mask = ISR_GET_CURRENT_MASK(cpu);
 	cur_exmask = EXISR_GET_CURRENT_MASK(cpu);
@@ -613,11 +616,6 @@ av530_intr(struct trapframe *eframe)
 	}
 #endif
 
-#ifdef MULTIPROCESSOR
-	if (old_spl < IPL_SCHED)
-		__mp_lock(&kernel_lock);
-#endif
-
 	/*
 	 * We want to service all interrupts marked in the IST register
 	 * They are all valid because the mask would have prevented them
@@ -706,10 +704,20 @@ av530_intr(struct trapframe *eframe)
 			 */
 			ret = 0;
 			SLIST_FOREACH(intr, list, ih_link) {
+#ifdef MULTIPROCESSOR
+				need_lock = intr->ih_ipl < IPL_SCHED &&
+				    intr->ih_ipl != IPL_CLOCK;
+				if (need_lock)
+					__mp_lock(&kernel_lock);
+#endif
 				if (ISSET(intr->ih_flags, INTR_WANTFRAME))
 					ret = (*intr->ih_fn)((void *)eframe);
 				else
 					ret = (*intr->ih_fn)(intr->ih_arg);
+#ifdef MULTIPROCESSOR
+				if (need_lock)
+					__mp_unlock(&kernel_lock);
+#endif
 				if (ret != 0) {
 					intr->ih_count.ec_count++;
 					break;
@@ -760,11 +768,6 @@ av530_intr(struct trapframe *eframe)
 		problems = 0;
 #endif
 
-#ifdef MULTIPROCESSOR
-	if (old_spl < IPL_SCHED)
-		__mp_unlock(&kernel_lock);
-#endif
-
 out:
 	/*
 	 * process any remaining data access exceptions before