From 735b5709a0ea1a62ca9f95abc01432736f858bbb Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 19 Dec 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-12-19

---
 carrera/dat.h      | 10 +---------
 carrera/devether.c | 18 ++++--------------
 carrera/main.c     |  4 ----
 carrera/mmu.c      |  3 ++-
 carrera/trap.c     | 47 +++++++++++++++++++++++-----------------------
 port/page.c        |  1 -
 6 files changed, 30 insertions(+), 53 deletions(-)

diff --git a/carrera/dat.h b/carrera/dat.h
index 8bc38b8e21b1a495f8358c3a1192260bd8db9a0a..3bde0df8612eaaf282456d7bb4b312fc82f36cc3 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -48,11 +48,6 @@ struct Conf
 	ulong	base1;		/* base of bank 1 */
 	ulong	copymode;	/* 0 is copy on write, 1 is copy on reference */
 	int	monitor;
-
-	ulong	ipif;		/* Ip protocol interfaces */
-	ulong	ip;		/* Ip conversations per interface */
-	ulong	arp;		/* Arp table size */
-	ulong	frag;		/* Ip fragment assemble queue size */
 };
 
 /*
@@ -101,15 +96,12 @@ struct Mach
 	int	tlbfault;		/* # of tlb faults FIFTH */
 	int	tlbpurge;		/* MUST BE SIXTH */
 
-	/* the following is safe to move */
+	/* the following are safe to move */
 	ulong	otlbfault;		/* tlbfault at last sched */
 	ulong	ticks;			/* of the clock since boot time */
 	Label	sched;			/* scheduler wakeup */
-	Lock	alarmlock;		/* access to alarm list */
-	void*	alarm;			/* alarms bound to this clock */
 	int	lastpid;		/* last pid allocated on this machine */
 	Proc*	pidproc[NTLBPID];	/* proc that owns tlbpid on this mach */
-	Page*	ufreeme;		/* address of upage of exited process */
 	Ureg*	ur;
 	KMap*	kactive;		/* active on this machine */
 	int	knext;
diff --git a/carrera/devether.c b/carrera/devether.c
index c88dff4f2e1b3f5e97813107964a4816a287235c..59a8430f86cf2fe338af766f6af3dffea0fd2a00 100644
--- a/carrera/devether.c
+++ b/carrera/devether.c
@@ -15,8 +15,8 @@
 
 #define SONICADDR	((Sonic*)Sonicbase)
 
-#define RD(rn)		(sncdly(), *(ulong*)((ulong)&SONICADDR->rn^4))
-#define WR(rn, v)	(sncdly(), *(ulong*)((ulong)&SONICADDR->rn^4) = (v))
+#define RD(rn)		(delay(0), *(ulong*)((ulong)&SONICADDR->rn^4))
+#define WR(rn, v)	(delay(0), *(ulong*)((ulong)&SONICADDR->rn^4) = (v))
 #define ISquad(s)	if((ulong)s & 0x7) panic("sonic: Quad alignment");
 
 typedef struct Pbuf Pbuf;
@@ -250,16 +250,6 @@ Ether *ether[Nether];
 
 void sonicswap(void*, int);
 
-static void
-sncdly(void)
-{
-	int i, j, *pj;
-
-	pj = &j;
-	for(i = 0; i < 200; i++)
-		*pj++;
-}
-
 static void
 wus(ushort *a, ushort v)
 {
@@ -458,12 +448,13 @@ etherintr(void)
 		if(status == 0)
 			break;
 
+		/* Clear the interrupt cause */
 		WR(isr, status);
 	
 		/*
 		 * Transmission complete, for good or bad.
 		 */
-		if(status & (Txdn|Txer)){
+		if(status & (Txdn|Txer)) {
 			txpkt = &c->tda[c->ti];
 			while(txpkt->status != Host){
 				if(txpkt->status == Interface){
@@ -621,7 +612,6 @@ etherreset(void)
 	 * Set the physical ethernet address and
 	 * prime the interrupt handler.
 	 */
-
 	if(ether[0] == 0) {
 		ctlr = malloc(sizeof(Ether));
 		ether[0] = ctlr;
diff --git a/carrera/main.c b/carrera/main.c
index 23c3b61954dfd3d9b1a4bac8a836fe2b0fe73d6f..63fe1f939c80400e185944222a9869dd07715e86 100644
--- a/carrera/main.c
+++ b/carrera/main.c
@@ -391,10 +391,6 @@ confinit(void)
 	conf.nproc = 100;
 	conf.nswap = conf.npage*3;
 	conf.nimage = 200;
-	conf.ipif = 8;
-	conf.ip = 64;
-	conf.arp = 32;
-	conf.frag = 32;
 
 	conf.monitor = 1;
 
diff --git a/carrera/mmu.c b/carrera/mmu.c
index 374e652708a2de8ff988da5b3b1b067915259ea6..534fb365dc09a18d40f2cf4c5773acfc251282a9 100644
--- a/carrera/mmu.c
+++ b/carrera/mmu.c
@@ -156,7 +156,7 @@ kfault(Ureg *ur)
 		panic("kmapfault: %lux", addr);
 
 	k = &kpte[index];
-	if(k->virt == 0)
+	if(k->virt == 0 || k->ref < 1)
 		panic("kmapfault: unmapped %lux", addr);
 
 	for(f = m->kactive; f; f = f->konmach[mno])
@@ -211,6 +211,7 @@ mmuswitch(Proc *p)
 	tp = p->pidonmach[m->machno];
 	if(tp == 0)
 		tp = newtlbpid(p);
+
 	puttlbx(0, KZERO|PTEPID(tp), 0, 0, PGSZ4K);
 }
 
diff --git a/carrera/trap.c b/carrera/trap.c
index 0d7eb87b54c21560e2d60bca09484026dea5f251..af7ebe81b9096f710c702ec5157bb05298b88f1c 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -238,6 +238,9 @@ trap(Ureg *ur)
 
 	Default:
 	default:
+		((ulong*)0xA0020000)[7] = 0x87654321;
+		((void(*)(void))0xA001C020)();
+
 		if(user) {
 			spllo();
 			sprint(buf, "sys: %s", excname[ecode]);
@@ -278,36 +281,32 @@ trap(Ureg *ur)
 void
 intr(Ureg *ur)
 {
-	uchar devint;
+	static uchar devint;
 	ulong cause = ur->cause;
 
 	m->intr++;
 	cause &= INTR7|INTR6|INTR5|INTR4|INTR3|INTR2|INTR1|INTR0;
 
 	if(cause & INTR3) {
-		for(;;) {
-			devint = IO(uchar, Intcause);
-			if(devint == 0)
-				break;
-			switch(devint) {
-			default:
-				panic("unknown devint=#%lux", devint);
-			case 0x28:		/* Serial 1 */
-				NS16552intr(0);
-				break;
-			case 0x24:		/* Serial 2 */
-				NS16552intr(1);
-				break;
-			case 0x14:
-				etherintr();
-				break;
-			case 0x1C:
-				kbdintr();
-				break;
-			case 0x20:
-				mouseintr();
-				break;
-			}
+		devint = IO(uchar, Intcause);
+		switch(devint) {
+		default:
+			panic("unknown devint=#%lux", devint);
+		case 0x28:		/* Serial 1 */
+			NS16552intr(0);
+			break;
+		case 0x24:		/* Serial 2 */
+			NS16552intr(1);
+			break;
+		case 0x14:
+			etherintr();
+			break;
+		case 0x1C:
+			kbdintr();
+			break;
+		case 0x20:
+			mouseintr();
+			break;
 		}
 		cause &= ~INTR3;
 	}
diff --git a/port/page.c b/port/page.c
index b2ec448931bd352f2a535bce86ec8694c4d6473b..c0d9536a149ee6daeb69030a2f8740fb534f809d 100644
--- a/port/page.c
+++ b/port/page.c
@@ -134,7 +134,6 @@ print("! ");
 	else
 		palloc.tail = p->prev;
 
-
 	palloc.freecount--;
 	unlock(&palloc);