From 4d55f1cdece7317e730b9e8fdf816e0cf9cbeb5a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 13 Oct 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-10-13

---
 carrera/dat.h  |  10 ++
 carrera/fns.h  |   2 +-
 carrera/mmu.c  |   5 +-
 carrera/trap.c |   2 +-
 pc/dat.h       |  12 +++
 pc/main.c      |  19 ++--
 pc/mem.h       |   2 +
 pc/mmu.c       |  10 +-
 pc/trap.c      |  27 ++---
 port/cache.c   | 269 ++++++++++++++++++++++++++++++++++++++++++++++---
 port/chan.c    |   1 +
 port/dev.c     |   1 +
 port/devproc.c |   4 +-
 port/portdat.h |   5 +-
 14 files changed, 325 insertions(+), 44 deletions(-)

diff --git a/carrera/dat.h b/carrera/dat.h
index 5630ba3db1a5fc0c82d26405acee32d2a8d7172a..0efa888a6d03501c7bd5fcb399c76689cdad95f5 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -7,6 +7,7 @@ typedef struct Label	Label;
 typedef struct Lock	Lock;
 typedef struct Mach	Mach;
 typedef struct MMU	MMU;
+typedef struct Notsave	Notsave;
 typedef struct PMMU	PMMU;
 typedef struct Softtlb	Softtlb;
 typedef struct Ureg	Ureg;
@@ -78,6 +79,15 @@ struct PMMU
 	int	pidonmach[MAXMACH];
 };
 
+/*
+ *  things saved in the Proc structure during a notify
+ */
+struct Notsave
+{
+	ulong	svstatus;
+	ulong	svr1;
+};
+
 #include "../port/portdat.h"
 
 /* First FOUR members offsets known by l.s */
diff --git a/carrera/fns.h b/carrera/fns.h
index 0ec152d929251857feef5637424db7fb4ea7dbce..a0af9e4ea297b9abcfd65f0ac8af13266b1fa238 100644
--- a/carrera/fns.h
+++ b/carrera/fns.h
@@ -43,7 +43,7 @@ void	ioinit(int);
 int	iprint(char*, ...);
 int	kbdinit(void);
 int	kbdintr(void);
-void	kfault(ulong);
+void	kfault(Ureg*);
 KMap*	kmap(Page*);
 void	kmapinit(void);
 void	kmapinval(void);
diff --git a/carrera/mmu.c b/carrera/mmu.c
index 258376d5c82812bfb1ee9c4ae33cab682f3f42d1..41b39aa55089e8f3d0d3a8f9e7e45327e2bdff8d 100644
--- a/carrera/mmu.c
+++ b/carrera/mmu.c
@@ -4,6 +4,7 @@
 #include	"dat.h"
 #include	"fns.h"
 #include	"io.h"
+#include	"ureg.h"
 
 /*
  *  tlb entry 0 is used only by mmuswitch() to set the current tlb pid.
@@ -141,11 +142,13 @@ kunmap(KMap *k)
 }
 
 void
-kfault(ulong addr)
+kfault(Ureg *ur)
 {
 	KMap *k, *f;
 	ulong x, index, virt;
+	ulong addr;
 
+	addr = ur->badvaddr;
 	index = (addr & ~KMAPADDR) >> KMAPSHIFT;
 	if(index >= KPTESIZE)
 		panic("kmapfault: %lux", addr);
diff --git a/carrera/trap.c b/carrera/trap.c
index 251a185e1391b78a72cb04df1d1264eb82135833..f0031645ecc804e6d5b916f09db9cb28ccfec111 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -205,7 +205,7 @@ trap(Ureg *ur)
 			kernfault(ur, ecode);
 
 		if(!user && (ur->badvaddr & KMAPMASK) == KMAPADDR) {
-			kfault(ur->badvaddr);
+			kfault(ur);
 			break;
 		}
 
diff --git a/pc/dat.h b/pc/dat.h
index 9cd3e86fdf765bd4883302344d69ac3a6e94fb13..c6fac5e3d6284f3c58c391aabf90fb54b6311414 100644
--- a/pc/dat.h
+++ b/pc/dat.h
@@ -5,6 +5,7 @@ typedef struct Label	Label;
 typedef struct Lock	Lock;
 typedef struct MMU	MMU;
 typedef struct Mach	Mach;
+typedef struct Notsave	Notsave;
 typedef struct PCArch	PCArch;
 typedef struct Page	Page;
 typedef struct PMMU	PMMU;
@@ -96,6 +97,16 @@ struct PMMU
 	Page	*mmuused;	/* used page table pages */
 };
 
+/*
+ *  things saved in the Proc structure during a notify
+ */
+struct Notsave
+{
+	ulong	svflags;
+	ulong	svcs;
+	ulong	svss;
+};
+
 #include "../port/portdat.h"
 
 /*
@@ -177,6 +188,7 @@ struct ISAConf {
 
 extern int	flipD[];		/* for flipping bitblt destination polarity */
 extern PCArch	*arch;			/* PC architecture */
+extern int	cpuflag;		/* true if this is a CPU */
 
 extern Mach	*m;
 extern Proc	*up;
diff --git a/pc/main.c b/pc/main.c
index db0ae715c73bd2f3818ed7bb75af5d75342fc7d4..5b7c8825909f9b14561ad8882ae0c820dd735cf9 100644
--- a/pc/main.c
+++ b/pc/main.c
@@ -94,6 +94,15 @@ machinit(void)
 
 ulong garbage;
 
+void
+ksetterm(char *f)
+{
+	char buf[2*NAMELEN];
+
+	sprint(buf, f, conffile);
+	ksetenv("terminal", buf);
+}
+
 void
 init0(void)
 {
@@ -101,9 +110,6 @@ init0(void)
 	char tstr[32];
 
 	up->nerrlab = 0;
-	m->proc = up->p;
-	up->state = Running;
-	up->mach = m;
 
 	spllo();
 
@@ -136,7 +142,6 @@ userinit(void)
 {
 	Proc *p;
 	Segment *s;
-	User *up;
 	KMap *k;
 	Page *pg;
 
@@ -434,12 +439,12 @@ matherror(Ureg *ur)
 		if((1<<i) & status){
 			msg = mathmsg[i];
 			sprint(note, "sys: fp: %s fppc=0x%lux", msg, up->fpsave.pc);
-			postnote(up->p, 1, note, NDebug);
+			postnote(up, 1, note, NDebug);
 			break;
 		}
 	if(msg == 0){
 		sprint(note, "sys: fp: unknown fppc=0x%lux", up->fpsave.pc);
-		postnote(up->p, 1, note, NDebug);
+		postnote(up, 1, note, NDebug);
 	}
 	if(ur->pc & KZERO)
 		panic("fp: status %lux fppc=0x%lux pc=0x%lux", status,
@@ -534,7 +539,7 @@ procrestore(Proc *p)
 void
 exit(int ispanic)
 {
-	u = 0;
+	up = 0;
 	print("exiting\n");
 	if(ispanic){
 		if(cpuflag)
diff --git a/pc/mem.h b/pc/mem.h
index f29cda42312856dbc2ffe89b5e7140b6e2a27ba0..25c3b4dd722acf5688fe2f306b03d9607691fc4f 100644
--- a/pc/mem.h
+++ b/pc/mem.h
@@ -117,3 +117,5 @@
  *  flag register bits that we care about
  */
 #define IFLAG	0x200
+
+#define getpgcolor(a)	0
diff --git a/pc/mmu.c b/pc/mmu.c
index c4ca0088078dd3c1728f8bda562607ca4b7f0552..b3b66444dbdcb519e3aa08ffd311a9b44fe48ebf 100644
--- a/pc/mmu.c
+++ b/pc/mmu.c
@@ -165,7 +165,7 @@ mmuinit(void)
 	 *  set up the task segment
 	 */
 	memset(&tss, 0, sizeof(tss));
-	taskswitch(ktoppg.pa, BY2BG + (ulong)m);
+	taskswitch(ktoppg.pa, BY2PG + (ulong)m);
 	puttr(TSSSEL);
 }
 
@@ -218,9 +218,9 @@ mmuswitch(Proc *p)
 
 	/* tell processor about new page table (flushes cached entries) */
 	if(p->mmutop)
-		taskswitch(p->mmutop->pa, p->kstack+KSTACK);
+		taskswitch(p->mmutop->pa, (ulong)(p->kstack+KSTACK));
 	else
-		taskswitch(ktoppg.pa, p->kstack+KSTACK);
+		taskswitch(ktoppg.pa, (ulong)(p->kstack+KSTACK));
 }
 
 /*
@@ -273,7 +273,7 @@ putmmu(ulong va, ulong pa, Page *pg)
 		memmove((void*)pg->va, (void*)ktoppg.va, BY2PG);
 		up->mmutop = pg;
 	}
-	top = (ulong*)up->mmutoup->va;
+	top = (ulong*)up->mmutop->va;
 	topoff = TOPOFF(va);
 
 	/*
@@ -305,7 +305,7 @@ putmmu(ulong va, ulong pa, Page *pg)
 	pt[BTMOFF(va)] = pa | PTEUSER;
 
 	/* flush cached mmu entries */
-	taskswitch(up->mmutoup->pa, up->kstack);
+	taskswitch(up->mmutop->pa, (ulong)up->kstack);
 	splx(s);
 }
 
diff --git a/pc/trap.c b/pc/trap.c
index b5ef247bd18f1e6d9a83ea3f41f81a64cb99d2dc..ddbc73e940ce145952f72cbe4ce05443ab4e8282 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -103,7 +103,7 @@ debugbpt(Ureg *ur)
 	/* restore pc to instruction that caused the trap */
 	ur->pc--;
 	sprint(buf, "sys: breakpoint");
-	postnote(up->p, 1, buf, NDebug);
+	postnote(up, 1, buf, NDebug);
 }
 
 /*
@@ -261,7 +261,7 @@ lastur = ur;
 		if(v <= 16){
 			if(user){
 				sprint(buf, "sys: trap: %s", excname[v]);
-				postnote(up->p, 1, buf, NDebug);
+				postnote(up, 1, buf, NDebug);
 				return;
 			} else {
 				dumpregs(ur);
@@ -308,10 +308,7 @@ dumpregs2(Ureg *ur)
 		print("registers for kernel\n");
 	print("FLAGS=%lux TRAP=%lux ECODE=%lux CS=%lux PC=%lux", ur->flags, ur->trap,
 		ur->ecode, ur->cs&0xff, ur->pc);
-	if(ur == (Ureg*)UREGADDR)
-		print(" SS=%lux USP=%lux\n", ur->ss&0xff, ur->usp);
-	else
-		print("\n");
+	print(" SS=%lux USP=%lux\n", ur->ss&0xff, ur->usp);
 	print("  AX %8.8lux  BX %8.8lux  CX %8.8lux  DX %8.8lux\n",
 		ur->ax, ur->bx, ur->cx, ur->dx);
 	print("  SI %8.8lux  DI %8.8lux  BP %8.8lux\n",
@@ -340,7 +337,7 @@ dumpstack(void)
 		return;
 
 	i = 0;
-	for(l=(ulong)&l; l<up->kstack+BY2PG; l+=4){
+	for(l=(ulong)&l; l<(ulong)(up->kstack+BY2PG); l+=4){
 		v = *(ulong*)l;
 		if(KTZERO < v && v < (ulong)&etext){
 			print("%lux ", v);
@@ -358,18 +355,24 @@ long
 execregs(ulong entry, ulong ssize, ulong nargs)
 {
 	ulong *sp;
+	Ureg *ur;
 
 	sp = (ulong*)(USTKTOP - ssize);
 	*--sp = nargs;
-	((Ureg*)UREGADDR)->usp = (ulong)sp;
-	((Ureg*)UREGADDR)->pc = entry;
+
+	ur = up->dbgreg;
+	ur->usp = (ulong)sp;
+	ur->pc = entry;
 	return USTKTOP-BY2WD;			/* address of user-level clock */
 }
 
 ulong
 userpc(void)
 {
-	return ((Ureg*)UREGADDR)->pc;
+	Ureg *ur;
+
+	ur = (Ureg*)up->dbgreg;
+	return ur->pc;
 }
 
 /*
@@ -411,7 +414,7 @@ syscall(Ureg *ur)
 	if(!waserror()){
 		if(up->scallnr >= sizeof systab/BY2WD){
 			pprint("bad sys call number %d pc %lux\n", up->scallnr, ur->pc);
-			postnote(up->p, 1, "sys: bad sys call", NDebug);
+			postnote(up, 1, "sys: bad sys call", NDebug);
 			error(Ebadarg);
 		}
 
@@ -464,7 +467,7 @@ notify(Ureg *ur)
 	Note *n;
 
 	if(up->procctl)
-		procctl(up->p);
+		procctl(up);
 	if(up->nnote == 0)
 		return 0;
 
diff --git a/port/cache.c b/port/cache.c
index ab667d9f98a85bd79021b535c800a920161f22bc..f2cb2b1cfe8bcda5bc6efbeb70cf0bdf4d8e7de1 100644
--- a/port/cache.c
+++ b/port/cache.c
@@ -6,26 +6,269 @@
 #include	"../port/error.h"
 #include	"devtab.h"
 
-typedef struct Fcache Fcache;
-typedef struct Fcalloc Fcalloc;
-struct Fcache
+Image	fscache;
+
+typedef Extent Extent;
+struct Extent
+{
+	int	bid;
+	ulong	start;
+	int	len;
+	Extent	*next;
+};
+
+typedef struct Mntcache Mntcache;
+struct Mntcache
 {
-	QLock;
 	Qid;
-	Page*	alloc;
-	Fcache*	hash;
-	Fcache*	next;
+	int	dev;
+	int	type;
+	Qlock;
+	Extent	 *list;
+	Mntcache *hash;
+	Mntcache *prev;
+	Mntcache *next;
 };
 
-struct Fcalloc
+typedef struct Cache Cache;
+struct Cache
 {
-	ulong	start;
-	short	len;
-	Page*	data;
+	Ref;
+	Mntcache	*head;
+	Mntcache	*tail;
+	Mntcache	*hash[NHASH];
 };
+Cache cache;
+
+Mntcache*
+clook(Chan *c)
+{
+	int h;
+
+	h = c->qid.path%NHASH;
+
+	lock(&cache);
+	for(m = cache.hash[h]; m; m = m->hash) {
+		if(m->path == c->path) {
+			qlock(m);
+			if(m->path == c->qid.path)
+			if(m->dev  == c->dev)
+			if(m->type == c->type) {
+				unlock(&cache);
+				return m;
+			}
+			qunlock(m);
+		}
+	}
+	unlock(&cache);
+	return 0;
+}
 
-Fcache*
-clook(Qid *qid)
+void
+cnodata(Mntcache *m)
 {
+	Extent *e, *n;
+
+	/*
+	 * Invalidate all extent data
+	 * Image lru will waste the pages
+	 */
+	for(e = m->list; e; e = n) {
+		n = e->list;
+		free(e);
+	}
+}
+
+void
+ctail(Mntcache *m)
+{
+	lock(&cache);
+
+	/* Unlink and send to the tail */
+	if(m->prev) 
+		m->prev->next = m->next;
+	else
+		cache.head = m->next;
+	if(m->next)
+		m->next->prev = m->prev;
+	else
+		cache.tail = m->prev;
+
+	if(cache.tail) {
+		m->prev = cache.tail;
+		cache.tail->next = m;
+		m->next = 0;
+		cache.tail = m;
+	}
+	else {
+		cache.head = cache.tail = m;
+		m->prev = m->next = 0;
+	}
+
+	unlock(&cache);
+}
+
+void
+copen(Chan *c)
+{
+	Mntcache *m, *f, **l;
+
+	m = clook(c);
+	if(m != 0) {
+		/* File was updated */
+		if(m->vers != c->vers)
+			cnodata(m);
+
+		ctail(m);
+		qunlock(m);
+		return;
+	}
+
+	/* LRU the cache headers */
+	m = cache.head;
+	qlock(m);
+	lock(cache);
+	l = &cache.hash[m->qid.path%NHASH];
+	for(f = *l; f; f = f->next) {
+		if(f == m) {
+			*l = f->next;
+			break;
+		}
+		l = &f->next;
+	}
+	l = &cache.hash[c->qid.path%NHASH];
+	m->hash = *l;
+	*l = m;
+	unlock(cache);
+	m->qid = c->qid;
+	m->dev = c->dev;
+	m->type = c->type;
+	cnodata(m);
+	ctail(m);
+	c->mcp = m;
+	qunlock(m);
+}
+
+static int
+cdev(Mntcache *m, Chan *c)
+{
+	if(m->path != c->path)
+		return 0;
+	if(m->vers != c->vers)
+		return 0;
+	if(m->dev != c->dev)
+		return 0;
+	if(m->type != c->type)
+		return 0;
+	return 1;
+}
+
+int
+cread(Chan *c, uchar *buf, int len, long offset)
+{
+	KMap *k;
+	Page *p;
+	Mntcache *m;
+	Extent *e, **l;
+	int o, l, total;
+
+	m = c->mcp;
+	if(m == 0)
+		return 0;
+	qlock(m);
+	if(cdev(m, c) == 0) {
+		qunlock(m);
+		return 0;
+	}
+
+	end = offset+len;
+	l = &m->list;
+	for(e = *l; e; e = e->next) {
+		if(e->start >= offset && e->start+e->len < end)
+			break;
+		l = &e->next;
+	}
+
+	if(e == 0) {
+		qunlock(m);
+		return 0;
+	}
+
+	total = 0;
+	while(len) {
+		p = lookpage(&fscache, e->bid);
+		if(p == 0) {
+			*l = e->next;
+			free(e);
+			qunlock(m);
+			return total;
+		}
+
+		k = kmap(p);
+		if(waserror()) {
+			kunmap(k);
+			putpage(p);
+			qunlock(m);
+			nexterror();
+		}
+
+		o = offset - e->start;
+		l = len;
+		if(l > e->len-o)
+			l = e->len-o;
+
+		p = (uchar*)VA(k) + o;
+		memset(buf, p, l);
+		kunmap(k);
+		putpage(p);
+
+		buf += l;
+		len -= l;
+		offset += l;
+		total += l;
+		l = &e->next;
+		e = e->next;
+		if(e == 0 || e->start != offset)
+			break;
+	}
+	qunlock(m)
+	return total;
+}
+
+void
+cwrite(Chan *c, uchar *buf, int len, long offset)
+{
+	Extent *e;
+	Mntcache *m;
+
+	if(offset > MAXCACHE)
+		return;
+
+	m = c->mcp;
+	if(m == 0)
+		return;
+	qlock(m);
+	if(cdev(m, c) == 0) {
+		qunlock(m);
+		return;
+	}
 
+	if(m->list == 0) {
+		e = malloc(sizeof(Extent));
+		if(e == 0)
+			return;
+		e->start = offset;
+		l = len;
+		if(l > BY2PG)
+			l = BY2PG;
+		p = auxpage();
+		if(p == 0)
+			return;
+		e->bid = incref(&cache);
+		p->daddr = e->bid;
+		cachepage(p, fscache);
+		k = kmap(p);
+		
+		kunmap(p);
+	}
 }
diff --git a/port/chan.c b/port/chan.c
index 943b375ec50414bb248c9d7548639fa0661ab9c4..d201d77dcc7e8449a8cbbd97aad109e96ee2b601 100644
--- a/port/chan.c
+++ b/port/chan.c
@@ -99,6 +99,7 @@ newchan(void)
 	c->aux = 0;
 	c->mchan = 0;
 	c->path = 0;
+	c->mcp = 0;
 	c->mqid = (Qid){0, 0};
 	return c;
 }
diff --git a/port/dev.c b/port/dev.c
index c80c210993488b3f09ec5510eaba6e8f31aa9199..f2d0774fe5b65c225eaa290a6e22d1ddaddb2d7e 100644
--- a/port/dev.c
+++ b/port/dev.c
@@ -98,6 +98,7 @@ devclone(Chan *c, Chan *nc)
 	nc->aux = c->aux;
 	nc->mchan = c->mchan;
 	nc->mqid = c->mqid;
+	nc->mcp = c->mcp;
 	nc->path = c->path;
 	incref(nc->path);
 	return nc;
diff --git a/port/devproc.c b/port/devproc.c
index 78f347cb470fd50fcd3504a3fdd47fead5156b6a..e5b58f323b81b4a3c71d1b8a85683c8f2284a665 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -243,7 +243,6 @@ procwstat(Chan *c, char *db)
 	if(c->qid.path&CHDIR)
 		error(Eperm);
 
-	convM2D(db, &d);
 	p = proctab(SLOT(c->qid));
 	if(p->pid != PID(c->qid))
 		error(Eprocdied);
@@ -251,13 +250,14 @@ procwstat(Chan *c, char *db)
 	if(strcmp(up->user, p->user) != 0 && strcmp(up->user, eve) != 0)
 		error(Eperm);
 
+	convM2D(db, &d);
 	p->procmode = d.mode&0777;
 }
 
 void
 procclose(Chan * c)
 {
-	if(QID(c->qid) == Qns)
+	if(QID(c->qid) == Qns && c->aux != 0)
 		free(c->aux);
 }
 
diff --git a/port/portdat.h b/port/portdat.h
index b77042a0858dad697de0c694636b5e1a57114036..b119c7b0da11e4e8198c9b64b3bbc54ee26db738 100644
--- a/port/portdat.h
+++ b/port/portdat.h
@@ -11,6 +11,7 @@ typedef struct Image	Image;
 typedef struct IOQ	IOQ;
 typedef struct KIOQ	KIOQ;
 typedef struct List	List;
+typedef struct Mntcache Mntcache;
 typedef struct Mount	Mount;
 typedef struct Mntrpc	Mntrpc;
 typedef struct Mntwalk	Mntwalk;
@@ -135,6 +136,7 @@ struct Chan
 	Mount	*mnt;			/* mount point that derived Chan */
 	Mount	*xmnt;			/* Last mount point crossed */
 	ulong	mountid;
+	Mntcache *mcp;			/* Mount cache pointer */
 	union {
 		void	*aux;
 		Qid	pgrpid;		/* for #p/notepg */
@@ -597,8 +599,7 @@ struct Proc
 
 	void	*ureg;		/* User registers for notes */
 	void	*dbgreg;	/* User registers for devproc */
-	ulong	svstatus;
-	ulong	svr1;
+	Notsave;
 
 	/*
 	 *  machine specific MMU