7 files changed, 51 insertions(+), 44 deletions(-)

M port/fault.c
M port/proc.c
M port/stream.c
M port/sysfile.c
M power/devbit3.c
M power/mem.h
M power/mmu.c

@@ 87,7 87,7 @@ fault(ulong addr, int read)
 				qunlock(&o->chan->rdl);
 				pg->o = 0;
 				pg->ref--;
-				pexit("load i/o error", 0);
+				pexit("demand load i/o error", 0);
 			}
 			l = (char*)VA(k);
 			if((*devtab[o->chan->type].read)(o->chan, l, n, (addr-o->va) + o->minca) != n)

@@ 118,6 118,7 @@ ready(Proc *p)
 	int s;
 
 	s = splhi();
+
 	if(p->state == Running)
 		rq = &runloq;
 	else

@@ 1149,7 1149,7 @@ streamread(Chan *c, void *vbuf, long n)
 			putbq(q, bp);
 			left = 0;
 		}
-	};
+	}
 
 	qunlock(&s->rdlock);
 	poperror();

@@ 227,6 227,7 @@ sysread(ulong *arg)
 	c = fdtochan(arg[0], OREAD);
 	validaddr(arg[1], arg[2], 1);
 	qlock(&c->rdl);
+
 	if(waserror()){
 		qunlock(&c->rdl);
 		nexterror();


@@ 255,6 256,7 @@ syswrite(ulong *arg)
 	c = fdtochan(arg[0], OWRITE);
 	validaddr(arg[1], arg[2], 0);
 	qlock(&c->wrl);
+
 	if(waserror()){
 		qunlock(&c->wrl);
 		nexterror();

@@ 30,9 30,6 @@ enum
 void
 bit3send(Bit3msg *bp, ulong cmd, void *addr, ulong count)
 {
-	int entry;
-
-	entry = MACHP(0)->ticks;
 	do; while(*BIT3ADDR);
 	bp->cmd = cmd;
 	bp->addr = (ulong)addr;


@@ 40,7 37,6 @@ bit3send(Bit3msg *bp, ulong cmd, void *addr, ulong count)
 	*BIT3ADDR = bp;
 	wbflush();
 	do; while(*BIT3HOLD);
-	m->spinlock += entry - MACHP(0)->ticks;
 	*BIT3INTR = 0x20;
 
 }


@@ 139,6 135,7 @@ bit3read(Chan *c, void *buf, long n, ulong offset)
 {
 	Bit3msg *bp;
 	int docpy;
+	ulong t0;
 
 	switch(c->qid.path){
 	case 1:


@@ 153,9 150,11 @@ bit3read(Chan *c, void *buf, long n, ulong offset)
 			qlock(&bit3);
 			bit3send(bp, READ, buf, n);
 			qunlock(&bit3);
+			t0 = MACHP(0)->ticks;
 			do
 				n = bp->rcount;
 			while(n == 0);
+			m->spinlock += MACHP(0)->ticks - t0;
 		}else{
 			/*
 			 *  use bit3 buffer.  lock the buffer till the reply


@@ 166,9 165,11 @@ bit3read(Chan *c, void *buf, long n, ulong offset)
 			qlock(&bit3);
 			bit3send(bp, READ, bit3.buf, n);
 			qunlock(&bit3);
+			t0 = MACHP(0)->ticks;
 			do
 				n = bp->rcount;
 			while(n == 0);
+			m->spinlock += MACHP(0)->ticks - t0;
 			memmove(buf, bit3.buf, n);
 			qunlock(&bit3.buflock);
 		}

@@ 99,7 99,7 @@
 #define TLBPID(n)	(((n)>>6)&0x3F)
 
 /* N.B. MUST CHANGE l.s utlbmiss if you want to change this */
-#define STLBLOG		13
+#define STLBLOG		11
 #define STLBSIZE	(1<<STLBLOG)
 
 #define	NTLBPID	64	/* number of pids */

@@ 40,25 40,26 @@ newtlbpid(Proc *p)
 	if(s >= NTLBPID)
 		s = 1;
 	i = s;
-	for(h = m->pidhere; h[i] && i != s; i = (i == NTLBPID - 1 ? 1 : i + 1))
-		;
-	
+	h = m->pidhere;
+	do{
+		i++;
+		if(i >= NTLBPID)
+			i = 1;
+	}while(h[i] && i != s);
+
 	if(i == s){
 		i++;
 		if(i >= NTLBPID)
 			i = 1;
 	}
-	
+	if(h[i])
+		purgetlb(i);
 	sp = m->pidproc[i];
-	m->lastpid = i;
+	if(sp && sp->pidonmach[m->machno] == i)
+		sp->pidonmach[m->machno] = 0;
 	m->pidproc[i] = p;
 	p->pidonmach[m->machno] = i;
-	if(sp){
-		if(sp->pidonmach[m->machno] == i)
-			sp->pidonmach[m->machno] = 0;
-		if(h[i])
-			purgetlb(i);
-	}
+	m->lastpid = i;
 	return i;
 }
 


@@ 85,48 86,50 @@ putmmu(ulong tlbvirt, ulong tlbphys)
 	spllo();
 }
 
-#ifdef POPCNT
-void
-stlbpopcnt(void)
-{
-	Softtlb *entry, *etab;
-	
-	entry = m->stb;
-	etab = &entry[STLBSIZE];
-	for(; entry < etab; entry++)
-		if(entry->virt)
-			m->spinlock++;
-
-	m->spinlock /= 2;
-}
-#endif
-
 void
 purgetlb(int pid)
 {
 	Softtlb *entry, *etab;
-	char *p;
+	char *pidhere;
 	Proc *sp, **pidproc;
 	int i, rpid, mno;
+	char dead[NTLBPID];
 
 	m->tlbpurge++;
-	p = m->pidhere;
+	/*
+	 * find all pid entries that are no longer used by processes
+	 */
+	mno = m->machno;
+	pidproc = m->pidproc;
+	memset(dead, 0, sizeof dead);
+	for(i=1; i<NTLBPID; i++){
+		sp = pidproc[i];
+		if(!sp || sp->pidonmach[mno] != i){
+			pidproc[i] = 0;
+			dead[i] = 1;
+		}
+	}
+	dead[pid] = 1;
+	/*
+	 * clean out all dead pids from the stlb;
+	 * garbage collect any pids with no entries
+	 */
 	memset(m->pidhere, 0, sizeof m->pidhere);
+	pidhere = m->pidhere;
 	entry = m->stb;
 	etab = &entry[STLBSIZE];
-	mno = m->machno;
-	pidproc = m->pidproc;
 	for(; entry < etab; entry++){
 		rpid = TLBPID(entry->virt);
-		sp = pidproc[rpid];
-		if(rpid == pid || !sp || sp->pidonmach[mno] != rpid){
-			entry->phys = 0;
+		if(dead[rpid])
 			entry->virt = 0;
-		}else
-			p[rpid] = 1;
+		else
+			pidhere[rpid] = 1;
 	}
+	/*
+	 * clean up the hardware
+	 */
 	for(i=TLBROFF; i<NTLB; i++)
-		if(!p[TLBPID(gettlbvirt(i))])
+		if(!pidhere[TLBPID(gettlbvirt(i))])
 			puttlbx(i, KZERO | PTEPID(i), 0);
 }