From 6bbc6be280c7cad0522c20cd2158362919c13472 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 26 Jun 2000 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2000-06-26

---
 pc/trap.c  |  8 +-------
 port/tod.c | 54 ++++++++++++++++++++++++++++++++----------------------
 2 files changed, 33 insertions(+), 29 deletions(-)

diff --git a/pc/trap.c b/pc/trap.c
index 453f057dfb790e4db04bb3e7b261f09c02bdf124..07050fff83737dab78ac3dff0b1d118d9739797e 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -19,7 +19,7 @@ void
 intrenable(int irq, void (*f)(Ureg*, void*), void* a, int tbdf, char *name)
 {
 	int vno;
-	Vctl *v, *p;
+	Vctl *v;
 
 	v = xalloc(sizeof(Vctl));
 	v->isintr = 1;
@@ -36,12 +36,6 @@ intrenable(int irq, void (*f)(Ureg*, void*), void* a, int tbdf, char *name)
 		iunlock(&vctllock);
 		print("intrenable: couldn't enable irq %d, tbdf 0x%uX for %s\n",
 			irq, tbdf, v->name);
-		if(p=vctl[vno]){
-			print("intrenable: irq %d is already used by", irq);
-			for(; p; p=p->next)
-				print(" %s", p->name);
-			print("\n");
-		}
 		xfree(v);
 		return;
 	}
diff --git a/port/tod.c b/port/tod.c
index ed2ac075340471d4d054f9e48eab2fb54cc1031c..371e9a086853b0b428f9851e62ca07193945bb27 100644
--- a/port/tod.c
+++ b/port/tod.c
@@ -22,12 +22,16 @@
 //
 //  each time f is set.  f is normally set by a user level
 //  program writing to /dev/fastclock.
+//
+//  We assume that the cpu's of a multiprocessor are synchronized.
+//  This assumption needs to be questioned with each new architecture.
 
 
 // frequency of the tod clock
 #define TODFREQ	1000000000LL
 
 struct {
+	ulong	cnt;
 	Lock;
 	vlong	multiplier;	// t = off + (multiplier*ticks)>>31
 	vlong	hz;		// frequency of fast clock
@@ -103,37 +107,30 @@ todget(vlong *ticksp)
 	else
 		ticks = fastticks(nil);
 
-	/* since 64 bit ops are not atomix, we have to lock around them */
+	// since 64 bit loads are not atomic, we have to lock around them
 	ilock(&tod);
-	diff = ticks - tod.last;
+	tod.cnt++;
+
+	// add in correction
+	if(tod.sstart != tod.send){
+		t = MACHP(0)->ticks;
+		if(t >= tod.send)
+			t = tod.send;
+		tod.off = tod.off + tod.delta*(t - tod.sstart);
+		tod.sstart = t;
+	}
 
 	// convert to epoch
+	diff = ticks - tod.last;
 	x = (diff * tod.multiplier) >> 31;
 	x = x + tod.off;
 
-	if(m->machno == 0){
-
-		// add in correction
-		if(tod.sstart != tod.send){
-			t = MACHP(0)->ticks;
-			if(t >= tod.send)
-				t = tod.send;
-			tod.off = tod.off + tod.delta*(t - tod.sstart);
-			tod.sstart = t;
-		}
-
-		// protect against overflows
-		if(diff > tod.hz){
-			tod.last = ticks;
-			tod.off = x;
-		}
-	}
-
 	// time can't go backwards
 	if(x < tod.lasttime)
 		x = tod.lasttime;
 	else
 		tod.lasttime = x;
+
 	iunlock(&tod);
 
 	if(ticksp != nil)
@@ -149,12 +146,25 @@ void
 todfix(void)
 {
 	vlong ticks, diff;
+	uvlong x;
 
 	ticks = fastticks(nil);
 
 	diff = ticks - tod.last;
-	if(diff > tod.hz)
-		todget(nil);
+	if(diff > tod.hz){
+		ilock(&tod);
+	
+		// convert to epoch
+		diff = ticks - tod.last;
+		x = (diff * tod.multiplier) >> 31;
+		x = x + tod.off;
+	
+		// protect against overflows
+		tod.last = ticks;
+		tod.off = x;
+	
+		iunlock(&tod);
+	}
 }
 
 long