From 1d1285d53b346bc78b8aa35b566870badaa9d595 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 13 Jun 2002 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2002-06-13

---
 bitsy/dat.h       |  1 +
 bitsy/devether.c  | 85 ++++++++++++++++++++++++++++++++++++-----------
 bitsy/devpcmcia.c |  5 +--
 port/qio.c        |  2 +-
 4 files changed, 71 insertions(+), 22 deletions(-)

diff --git a/bitsy/dat.h b/bitsy/dat.h
index f0b43550e626a9a5b4f1540a523b7574cfe30496..9e3f03b60637a88ab04b0c85c10caefd2ff1f90d 100644
--- a/bitsy/dat.h
+++ b/bitsy/dat.h
@@ -255,6 +255,7 @@ struct PCMslot
  */
 struct DevConf
 {
+	RWlock;			/* write: configure/unconfigure/suspend; read: normal access */
 	ulong	mem;	/* mapped memory address */
 	ulong	port;		/* mapped i/o regs */
 	int		size;		/* access size */
diff --git a/bitsy/devether.c b/bitsy/devether.c
index d6faa38645e49f2ef50e26c045c62fc66d78a618..a25c39a68f2a0c1830825758d7705d5b8987de0d 100644
--- a/bitsy/devether.c
+++ b/bitsy/devether.c
@@ -37,14 +37,15 @@ etherconfig(int on, char *spec, DevConf *cf)
 	char name[32], buf[128];
 	char *p, *e;
 
-	/* can't unconfigure yet */
-	if(on == 0)
-		return -1;
-
 	ctlrno = atoi(spec);
 	if(etherxx[ctlrno] != nil)
 		return -1;
 
+	/* can't unconfigure yet */
+	if(on == 0){
+		return -1;
+	}
+
 	ether = malloc(sizeof(Ether));
 	if(ether == nil)
 		panic("etherconfig");
@@ -122,29 +123,46 @@ etherattach(char* spec)
 	if(etherxx[ctlrno] == 0)
 		error(Enodev);
 
+	rlock(etherxx[ctlrno]);
 	chan = devattach('l', spec);
 	chan->dev = ctlrno;
 	if(etherxx[ctlrno]->attach)
 		etherxx[ctlrno]->attach(etherxx[ctlrno]);
+	runlock(etherxx[ctlrno]);
 	return chan;
 }
 
 static Walkqid*
 etherwalk(Chan* chan, Chan* nchan, char** name, int nname)
 {
-	return netifwalk(etherxx[chan->dev], chan, nchan, name, nname);
+	Walkqid *q;
+
+	rlock(etherxx[chan->dev]);
+	q = netifwalk(etherxx[chan->dev], chan, nchan, name, nname);
+	runlock(etherxx[chan->dev]);
+	return q;
 }
 
 static int
 etherstat(Chan* chan, uchar* dp, int n)
 {
-	return netifstat(etherxx[chan->dev], chan, dp, n);
+	int s;
+
+	rlock(etherxx[chan->dev]);
+	s = netifstat(etherxx[chan->dev], chan, dp, n);
+	runlock(etherxx[chan->dev]);
+	return s;
 }
 
 static Chan*
 etheropen(Chan* chan, int omode)
 {
-	return netifopen(etherxx[chan->dev], chan, omode);
+	Chan *c;
+
+	rlock(etherxx[chan->dev]);
+	c = netifopen(etherxx[chan->dev], chan, omode);
+	runlock(etherxx[chan->dev]);
+	return c;
 }
 
 static void
@@ -155,7 +173,9 @@ ethercreate(Chan*, char*, int, ulong)
 static void
 etherclose(Chan* chan)
 {
+	rlock(etherxx[chan->dev]);
 	netifclose(etherxx[chan->dev], chan);
+	runlock(etherxx[chan->dev]);
 }
 
 static long
@@ -163,8 +183,10 @@ etherread(Chan* chan, void* buf, long n, vlong off)
 {
 	Ether *ether;
 	ulong offset = off;
+	long n;
 
 	ether = etherxx[chan->dev];
+	rlock(ether);
 	if((chan->qid.type & QTDIR) == 0 && ether->ifstat){
 		/*
 		 * With some controllers it is necessary to reach
@@ -176,19 +198,29 @@ etherread(Chan* chan, void* buf, long n, vlong off)
 			ether->ifstat(ether, buf, 0, offset);
 	}
 
-	return netifread(ether, chan, buf, n, offset);
+	n = netifread(ether, chan, buf, n, offset);
+	runlock(ether);
+	return n;
 }
 
 static Block*
 etherbread(Chan* chan, long n, ulong offset)
 {
-	return netifbread(etherxx[chan->dev], chan, n, offset);
+	Block *b;
+
+	rlock(etherxx[chan->dev]);
+	b = netifbread(etherxx[chan->dev], chan, n, offset);
+	runlock(etherxx[chan->dev]);
+	return b;
 }
 
 static int
 etherwstat(Chan* chan, uchar* dp, int n)
 {
-	return netifwstat(etherxx[chan->dev], chan, dp, n);
+	rlock(etherxx[chan->dev]);
+	n = netifwstat(etherxx[chan->dev], chan, dp, n);
+	runlock(etherxx[chan->dev]);
+	return n;
 }
 
 static void
@@ -334,30 +366,41 @@ etherwrite(Chan* chan, void* buf, long n, vlong)
 	Ether *ether;
 	Block *bp;
 	int nn;
+	long l;
 
 	ether = etherxx[chan->dev];
+	rlock(etherxx[chan->dev]);
 	if(NETTYPE(chan->qid.path) != Ndataqid) {
 		nn = netifwrite(ether, chan, buf, n);
-		if(nn >= 0)
+		if(nn >= 0){
+			runlock(etherxx[chan->dev]);
 			return nn;
-
-		if(ether->ctl!=nil)
-			return ether->ctl(ether,buf,n);
-			
+		}
+		if(ether->ctl!=nil){
+			l = ether->ctl(ether,buf,n);
+			runlock(etherxx[chan->dev]);
+			return l;
+		}
+		runlock(etherxx[chan->dev]);
 		error(Ebadctl);
 	}
 
-	if(n > ether->maxmtu)
+	if(n > ether->maxmtu){
+		runlock(etherxx[chan->dev]);
 		error(Etoobig);
-	if(n < ether->minmtu)
+	}
+	if(n < ether->minmtu){
+		runlock(etherxx[chan->dev]);
 		error(Etoosmall);
-
+	}
 	bp = allocb(n);
 	memmove(bp->rp, buf, n);
 	memmove(bp->rp+Eaddrlen, ether->ea, Eaddrlen);
 	bp->wp += n;
 
-	return etheroq(ether, bp);
+	l = etheroq(ether, bp);
+	runlock(etherxx[chan->dev]);
+	return l;
 }
 
 static long
@@ -377,16 +420,20 @@ etherbwrite(Chan* chan, Block* bp, ulong)
 		freeb(bp);
 		return n;
 	}
+	rlock(etherxx[chan->dev]);
 	ether = etherxx[chan->dev];
 
 	if(n > ether->maxmtu){
 		freeb(bp);
+		runlock(etherxx[chan->dev]);
 		error(Etoobig);
 	}
 	if(n < ether->minmtu){
 		freeb(bp);
+		runlock(etherxx[chan->dev]);
 		error(Etoosmall);
 	}
+	runlock(etherxx[chan->dev]);
 
 	return etheroq(ether, bp);
 }
diff --git a/bitsy/devpcmcia.c b/bitsy/devpcmcia.c
index 68bdb08af7519a160bd5324747bd57c520abccf5..5477297d3532491165e596a5a1cda87dd9a7c894 100644
--- a/bitsy/devpcmcia.c
+++ b/bitsy/devpcmcia.c
@@ -348,15 +348,16 @@ pcmctlwrite(char *p, long n, ulong, PCMslot *sp)
 		}
 
 		/* configure device */
-		cf.type = nil;
+		memset(&cf, 0, sizeof cf);
+		wlock(&cf);
 		kstrdup(&cf.type, cmd->f[2]);
 		cf.mem = (ulong)sp->mem;
 		cf.port = (ulong)sp->regs;
 		cf.itype = GPIOfalling;
 		cf.interrupt = bitno(sp == slot ? GPIO_CARD_IRQ0_i : GPIO_CARD_IRQ1_i);
-		cf.size = 0;
 		if(devtab[dtx]->config(1, p, &cf) < 0)
 			error("couldn't configure device");
+		wunlock(&cf);
 
 		wunlock(sp);
 		poperror();
diff --git a/port/qio.c b/port/qio.c
index 3f263741565ce0b8d300918038173055b9ddda7c..a513e0711c2fb9e4e6eed6a81f57ed2199e64f95 100644
--- a/port/qio.c
+++ b/port/qio.c
@@ -57,7 +57,7 @@ enum
 	Qflow		= (1<<3),
 	Qcoalesce	= (1<<4),	/* coallesce packets on read */
 
-	Maxatomic	= 32*1024,
+	Maxatomic	= 64*1024,
 };
 
 uint	qiomaxatomic = Maxatomic;