Import sources from 2011-03-30 iso image

1 files changed, 289 insertions, 0 deletions

diff --git a/sys/src/cmd/cwfs/iobuf.c b/sys/src/cmd/cwfs/iobuf.c
new file mode 100755
index 000000000..11879f37c
--- /dev/null
+++ b/sys/src/cmd/cwfs/iobuf.c
@@ -0,0 +1,289 @@
+#include	"all.h"
+#include	"io.h"
+
+enum { DEBUG = 0 };
+
+extern	long nhiob;
+extern	Hiob *hiob;
+
+Iobuf*
+getbuf(Device *d, Off addr, int flag)
+{
+	Iobuf *p, *s;
+	Hiob *hp;
+	Off h;
+
+	if(DEBUG)
+		print("getbuf %Z(%lld) f=%x\n", d, (Wideoff)addr, flag);
+	h = addr + (Off)(uintptr)d*1009;
+	if(h < 0)
+		h = ~h;
+	h %= nhiob;
+	hp = &hiob[h];
+
+loop:
+	lock(hp);
+
+/*
+ * look for it in the active list
+ */
+	s = hp->link;
+	for(p=s;;) {
+		if(p->addr == addr && p->dev == d) {
+			if(p != s) {
+				p->back->fore = p->fore;
+				p->fore->back = p->back;
+				p->fore = s;
+				p->back = s->back;
+				s->back = p;
+				p->back->fore = p;
+				hp->link = p;
+			}
+			unlock(hp);
+			qlock(p);
+			if(p->addr != addr || p->dev != d || iobufmap(p) == 0) {
+				qunlock(p);
+				goto loop;
+			}
+			p->flags |= flag;
+			return p;
+		}
+		p = p->fore;
+		if(p == s)
+			break;
+	}
+	if(flag & Bprobe) {
+		unlock(hp);
+		return 0;
+	}
+
+/*
+ * not found
+ * take oldest unlocked entry in this queue
+ */
+xloop:
+	p = s->back;
+	if(!canqlock(p)) {
+		if(p == hp->link) {
+			unlock(hp);
+			print("iobuf all locked\n");
+			goto loop;
+		}
+		s = p;
+		goto xloop;
+	}
+
+	/*
+	 * its dangerous to flush the pseudo
+	 * devices since they recursively call
+	 * getbuf/putbuf. deadlock!
+	 */
+	if(p->flags & Bres) {
+		qunlock(p);
+		if(p == hp->link) {
+			unlock(hp);
+			print("iobuf all reserved\n");
+			goto loop;
+		}
+		s = p;
+		goto xloop;
+	}
+	if(p->flags & Bmod) {
+		unlock(hp);
+		if(iobufmap(p)) {
+			if(!devwrite(p->dev, p->addr, p->iobuf))
+				p->flags &= ~(Bimm|Bmod);
+			iobufunmap(p);
+		}
+		qunlock(p);
+		goto loop;
+	}
+	hp->link = p;
+	p->addr = addr;
+	p->dev = d;
+	p->flags = flag;
+//	p->pc = getcallerpc(&d);
+	unlock(hp);
+	if(iobufmap(p))
+		if(flag & Brd) {
+			if(!devread(p->dev, p->addr, p->iobuf))
+				return p;
+			iobufunmap(p);
+		} else
+			return p;
+	else
+		print("iobuf cant map buffer\n");
+	p->flags = 0;
+	p->dev = devnone;
+	p->addr = -1;
+	qunlock(p);
+	return 0;
+}
+
+/*
+ * syncblock tries to put out a block per hashline
+ * returns 0 all done,
+ * returns 1 if it missed something
+ */
+int
+syncblock(void)
+{
+	Iobuf *p, *s, *q;
+	Hiob *hp;
+	long h;
+	int flag;
+
+	flag = 0;
+	for(h=0; h<nhiob; h++) {
+		q = 0;
+		hp = &hiob[h];
+		lock(hp);
+		s = hp->link;
+		for(p=s;;) {
+			if(p->flags & Bmod) {
+				if(q)
+					flag = 1;	/* more than 1 mod/line */
+				q = p;
+			}
+			p = p->fore;
+			if(p == s)
+				break;
+		}
+		unlock(hp);
+		if(q) {
+			if(!canqlock(q)) {
+				flag = 1;		/* missed -- was locked */
+				continue;
+			}
+			if(!(q->flags & Bmod)) {
+				qunlock(q);
+				continue;
+			}
+			if(iobufmap(q)) {
+				if(!devwrite(q->dev, q->addr, q->iobuf))
+					q->flags &= ~(Bmod|Bimm);
+				iobufunmap(q);
+			} else
+				flag = 1;
+			qunlock(q);
+		}
+	}
+	return flag;
+}
+
+void
+sync(char *reason)
+{
+	long i;
+
+	print("sync: %s\n", reason);
+	for(i=10*nhiob; i>0; i--)
+		if(!syncblock())
+			return;
+	print("sync shorted\n");
+}
+
+void
+putbuf(Iobuf *p)
+{
+
+	if(canqlock(p))
+		print("buffer not locked %Z(%lld)\n", p->dev, (Wideoff)p->addr);
+	if(p->flags & Bimm) {
+		if(!(p->flags & Bmod))
+			print("imm and no mod %Z(%lld)\n",
+				p->dev, (Wideoff)p->addr);
+		if(!devwrite(p->dev, p->addr, p->iobuf))
+			p->flags &= ~(Bmod|Bimm);
+	}
+	iobufunmap(p);
+	qunlock(p);
+}
+
+int
+checktag(Iobuf *p, int tag, Off qpath)
+{
+	Tag *t;
+	static Off lastaddr;
+
+	t = (Tag*)(p->iobuf+BUFSIZE);
+	if(t->tag != tag) {
+		if(p->flags & Bmod) {
+			print("\ttag = %d/%llud; expected %lld/%d -- not flushed\n",
+				t->tag, (Wideoff)t->path, (Wideoff)qpath, tag);
+			return 2;
+		}
+		if(p->dev != nil && p->dev->type == Devcw)
+			cwfree(p->dev, p->addr);
+		if(p->addr != lastaddr)
+			print("\ttag = %G/%llud; expected %G/%lld -- flushed (%lld)\n",
+				t->tag, (Wideoff)t->path, tag, (Wideoff)qpath,
+				(Wideoff)p->addr);
+		lastaddr = p->addr;
+		p->dev = devnone;
+		p->addr = -1;
+		p->flags = 0;
+		return 2;
+	}
+	if(qpath != QPNONE) {
+		if((qpath ^ t->path) & ~QPDIR) {
+			if(1 || CHAT(0))
+				print("\ttag/path = %llud; expected %d/%llux\n",
+					(Wideoff)t->path, tag, (Wideoff)qpath);
+			return 0;
+		}
+	}
+	return 0;
+}
+
+void
+settag(Iobuf *p, int tag, long qpath)
+{
+	Tag *t;
+
+	t = (Tag*)(p->iobuf+BUFSIZE);
+	t->tag = tag;
+	if(qpath != QPNONE)
+		t->path = qpath & ~QPDIR;
+	p->flags |= Bmod;
+}
+
+int
+qlmatch(QLock *q1, QLock *q2)
+{
+
+	return q1 == q2;
+}
+
+int
+iobufql(QLock *q)
+{
+	Iobuf *p, *s;
+	Hiob *hp;
+	Tag *t;
+	long h;
+	int tag;
+
+	for(h=0; h<nhiob; h++) {
+		hp = &hiob[h];
+		lock(hp);
+		s = hp->link;
+		for(p=s;;) {
+			if(qlmatch(q, p)) {
+				t = (Tag*)(p->iobuf+BUFSIZE);
+				tag = t->tag;
+				if(tag < 0 || tag >= MAXTAG)
+					tag = Tnone;
+				print("\tIobuf %Z(%lld) t=%s\n",
+					p->dev, (Wideoff)p->addr, tagnames[tag]);
+				unlock(hp);
+				return 1;
+			}
+			p = p->fore;
+			if(p == s)
+				break;
+		}
+		unlock(hp);
+	}
+	return 0;
+}