From d816200d503406772ac1b6901e3878c346a52ad1 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 24 Jan 2002 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2002-01-24

---
 mtx/fns.h      |  1 -
 mtx/l.s        |  2 +-
 mtx/main.c     |  6 ++----
 mtx/mmu.c      | 23 +++++++++++++++++------
 mtx/trap.c     | 37 +++++++++++++++++--------------------
 pc/ether8139.c |  2 +-
 port/sysproc.c |  2 ++
 7 files changed, 40 insertions(+), 33 deletions(-)

diff --git a/mtx/fns.h b/mtx/fns.h
index a6b0613b497a866247f2b8a2f355c8faded3ca3d..34f5f34e8b28d32a7903773057df69742ea4b261 100644
--- a/mtx/fns.h
+++ b/mtx/fns.h
@@ -18,7 +18,6 @@ void	evenaddr(ulong);
 void	faultpower(Ureg*, ulong addr, int read);
 void	firmware(void);
 void	fpinit(void);
-void	fpoff(Proc*);
 void	fprestore(FPsave*);
 void	fpsave(FPsave*);
 void	fptrap(Ureg*);
diff --git a/mtx/l.s b/mtx/l.s
index f934165c314ee15780d2a2a1b5025975c7637caf..9415ad95594f9b8a9fb964e494083e82451e90d6 100644
--- a/mtx/l.s
+++ b/mtx/l.s
@@ -416,7 +416,7 @@ TEXT	trapvec(SB), $-4
 ktrap:
 	MOVW	R1, CR
 	MOVW	SPR(SAVER1), R1
-	RLWNM	$0, R1, $~KZERO, R1		/* PADDR(m->proc->kstack) */
+	RLWNM	$0, R1, $~KZERO, R1		/* PADDR(R1) */
 	SUB	$UREGSPACE, R1
 	BL	saveureg(SB)
 	BL	trap(SB)
diff --git a/mtx/main.c b/mtx/main.c
index d209f6a65167cdbb9871b5781658ebc6e4d78b85..9772d8c23534069fdaf79e294f8012d52209fc46 100644
--- a/mtx/main.c
+++ b/mtx/main.c
@@ -55,9 +55,8 @@ machinit(void)
 	 */
 	m->loopconst = 100000;
 
-	/* turn on caches (instruction only for now) */
-//	puthid0(gethid0() | BIT(16));
-puthid0(gethid0() | BIT(16) | BIT(17));	/* and data */
+	/* turn on caches */
+	puthid0(gethid0() | BIT(16) | BIT(17));
 
 	active.machs = 1;
 	active.exiting = 0;
@@ -262,7 +261,6 @@ procsave(Proc *p)
 	if(p->fpstate == FPactive){
 		if(p->state != Moribund)
 			fpsave(&up->fpsave);
-//		fpoff(p);
 		p->fpstate = FPinactive;
 	}
 }
diff --git a/mtx/mmu.c b/mtx/mmu.c
index a44e515d5a866a958349c00adde034e5d8906482..604ea2b6fa8a7219148d50dd7615e97e8696913a 100644
--- a/mtx/mmu.c
+++ b/mtx/mmu.c
@@ -20,6 +20,8 @@ static struct {
 	ulong	size;			/* number of bytes in page table */
 	ulong	mask;		/* hash mask */
 	int		slotgen;		/* next pte (byte offset) when pteg is full */
+
+	int		pidlock;
 	int		pidgen;		/* next mmu pid to use */
 } ptab;
 
@@ -75,6 +77,12 @@ mmuswitch(Proc *p)
 {
 	int i, mp;
 
+	if(p->kp) {
+		for(i = 0; i < 8; i++)
+			putsr(i<<28, 0);
+		return;
+	}
+
 	if(p->newtlb) {
 		p->mmupid = 0;
 		p->newtlb = 0;
@@ -113,13 +121,13 @@ putmmu(ulong va, ulong pa, Page *pg)
 	p = (ulong*)pteg;
 	ep = (ulong*)(pteg+BY2PTEG);
 	q = nil;
-	lock(&ptab);
+	ilock(&ptab);
 	tlbflush(va);
 	while(p < ep) {
 		x = p[0];
 		if(x == ptehi) {
 			q = p;
-if(q[1] == pa) panic("putmmu already set pte");
+if(q[1] == pa) print("putmmu already set pte\n");
 			break;
 		}
 		if(q == nil && (x & BIT(0)) == 0)
@@ -133,7 +141,7 @@ if(q[1] == pa) panic("putmmu already set pte");
 	q[0] = ptehi;
 	q[1] = pa;
 	sync();
-	unlock(&ptab);
+	iunlock(&ptab);
 
 	ctl = &pg->cachectl[m->machno];
 	switch(*ctl) {
@@ -156,11 +164,14 @@ newmmupid(void)
 {
 	int pid;
 
-	lock(&ptab);
+	/* can't use lock() here as we're called from within sched() */
+	while(!tas(&ptab.pidlock))
+		;
 	pid = ptab.pidgen++;
-	unlock(&ptab);
 	if(pid > PIDMAX)
-		panic("newmmupid");
+		pid = PIDBASE;
+	ptab.pidlock = 0;
+	coherence();
 	up->mmupid = pid;
 	return pid;
 }
diff --git a/mtx/trap.c b/mtx/trap.c
index 3f351e1813bd872b3924aecfdc9ffc214aa4098c..867401e5c30c663beaef0210e3b0d232d83d2f10 100644
--- a/mtx/trap.c
+++ b/mtx/trap.c
@@ -313,12 +313,10 @@ faultpower(Ureg *ureg, ulong addr, int read)
 	user = (ureg->srr1 & MSR_PR) != 0;
 	insyscall = up->insyscall;
 	up->insyscall = 1;
-	spllo();
 	n = fault(addr, read);
 	if(n < 0){
 		if(!user){
 			dumpregs(ureg);
-//			_dumpstack(ureg);
 			panic("fault: 0x%lux", addr);
 		}
 		sprint(buf, "sys: trap: fault %s addr=0x%lux", read? "read" : "write", addr);
@@ -427,16 +425,6 @@ fpexcname(Ureg *ur, ulong fpscr, char *buf)
 	return buf;
 }
 
-void
-fpoff(Proc *p)
-{
-	Ureg *ur;
-
-	ur = p->dbgreg;
-	if(ur != nil)
-		ur->srr1 &= ~MSR_FP;
-}
-
 /*
  * Fill in enough of Ureg to get a stack trace, and call a function.
  * Used by debugging interface rdb.
@@ -462,19 +450,30 @@ callwithureg(void (*fn)(Ureg*))
 static void
 _dumpstack(Ureg *ureg)
 {
-	ulong l, v;
+	ulong l, sl, el, v;
 	int i;
 
-	if(up == 0)
+	l = (ulong)&l;
+	if(up == 0){
+		el = (ulong)m+BY2PG;
+		sl = el-KSTACK;
+	}
+	else{
+		sl = (ulong)up->kstack;
+		el = sl + KSTACK;
+	}
+	if(l > el || l < sl){
+		el = (ulong)m+BY2PG;
+		sl = el-KSTACK;
+	}
+	if(l > el || l < sl)
 		return;
-
 	print("ktrace /kernel/path %.8lux %.8lux %.8lux\n", ureg->pc, ureg->sp, ureg->lr);
 	i = 0;
-	for(l=(ulong)&l; l<(ulong)(up->kstack+KSTACK); l+=4){
+	for(; l < el; l += 4){
 		v = *(ulong*)l;
 		if(KTZERO < v && v < (ulong)etext){
 			print("%.8lux=%.8lux ", l, v);
-//delay(1);
 			if(i++ == 4){
 				print("\n");
 				i = 0;
@@ -494,9 +493,9 @@ dumpregs(Ureg *ur)
 {
 	int i;
 	ulong *l;
+
 	if(up) {
 		print("registers for %s %ld\n", up->text, up->pid);
-print("ur %lux\n", ur);
 		if(ur->srr1 & MSR_PR == 0)
 		if(ur->usp < (ulong)up->kstack || ur->usp > (ulong)up->kstack+KSTACK)
 			print("invalid stack ptr\n");
@@ -741,7 +740,6 @@ notify(Ureg* ur)
 		qunlock(&up->debug);
 		pexit(n->msg, n->flag!=NDebug);
 	}
-print("notify: old usp %lux\n", ur->usp);
 	sp = ur->usp & ~(BY2V-1);
 	sp -= sizeof(Ureg);
 
@@ -768,7 +766,6 @@ print("notify: old usp %lux\n", ur->usp);
 	up->nnote--;
 	memmove(&up->lastnote, &up->note[0], sizeof(Note));
 	memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));
-print("notify: usp %lux\n", ur->usp);
 
 	qunlock(&up->debug);
 	splx(s);
diff --git a/pc/ether8139.c b/pc/ether8139.c
index b9a4a261e50f25a40f734e261a7388869231b9b9..2c5bdbef621e9832cc659128e8c2394bb4e62783 100644
--- a/pc/ether8139.c
+++ b/pc/ether8139.c
@@ -169,7 +169,7 @@ enum {					/* Tsd0 */
 };
 
 enum {
-	Rblen		= Rblen64K,	/* Receive BUffer Length */
+	Rblen		= Rblen64K,	/* Receive Buffer Length */
 	Ntd		= 4,		/* Number of Transmit Descriptors */
 	Tdbsz		= ROUNDUP(sizeof(Etherpkt), 4),
 };
diff --git a/port/sysproc.c b/port/sysproc.c
index f1a53910612643fcf004a3e44b64c57b81e1bc80..867991070e14464a6225fb5d6e0f08bdb78dc350 100644
--- a/port/sysproc.c
+++ b/port/sysproc.c
@@ -640,6 +640,8 @@ generrstr(char *buf, uint nbuf)
 {
 	char tmp[ERRMAX];
 
+	if(nbuf == 0)
+		error(Ebadarg);
 	validaddr((ulong)buf, nbuf, 1);
 	if(nbuf > sizeof tmp)
 		nbuf = sizeof tmp;