From 30cd6c9fe8e2db2acd1ac8e56bfe4993e0fefaa9 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 29 Jan 1999 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1999-01-29

---
 pc/archgeneric.c |  8 +-----
 pc/clock.c       | 28 ++++++++++++++++++++
 pc/devrtc.c      | 69 ++++++++++++++++++++++++++++--------------------
 pc/main.c        |  6 ++---
 port/portfns.h   |  4 ++-
 5 files changed, 76 insertions(+), 39 deletions(-)

diff --git a/pc/archgeneric.c b/pc/archgeneric.c
index 6b9716ba81ebd3661c9911afcf5935cd5567b73e..ffbac101cf94e32a9ae1e0f6227c13fc079b7a8c 100644
--- a/pc/archgeneric.c
+++ b/pc/archgeneric.c
@@ -205,7 +205,7 @@ archinit(void)
 		coherence = wbflush;
 }
 
-static uvlong fasthz;
+extern uvlong fasthz;
 
 void
 cycletimerinit(void)
@@ -228,9 +228,3 @@ cycletimer(uvlong *hz)
 		*hz = fasthz;
 	return tsc;
 }
-
-uvlong
-fastticks(uvlong *hz)
-{
-	return (*arch->fastclock)(hz);
-}
diff --git a/pc/clock.c b/pc/clock.c
index 2fa498cc1ceeab515bffd70cf92af323b2c560d6..2b8c4f6e6a70883f5250be2f1a33702323a699ea 100644
--- a/pc/clock.c
+++ b/pc/clock.c
@@ -17,6 +17,11 @@ typedef struct Clock0link {
 static Clock0link *clock0link;
 static Lock clock0lock;
 
+/* for fast clock */
+static	vlong	fastoff;
+static	vlong	fastsecs;
+	uvlong	fasthz;
+
 void
 addclock0link(void (*clock)(void))
 {
@@ -96,3 +101,26 @@ microdelay(int microsecs)
 	aamloop(microsecs);
 }
 
+vlong
+fastticks(uvlong *hz)
+{
+	return (*arch->fastclock)(hz) + fastoff;
+}
+
+void
+syncfastticks(vlong secs)
+{
+	vlong x, ofastoff;
+	vlong err, deltat;
+
+	/* set new offset */
+	x = (*arch->fastclock)(nil);
+	ofastoff = fastoff;
+	fastoff = secs*fasthz - x;
+
+	/* calculate first order diversion rate */
+	err = fastoff - ofastoff;
+	deltat = secs - fastsecs;
+	fastsecs = secs;
+	deltat *= fasthz;
+}
diff --git a/pc/devrtc.c b/pc/devrtc.c
index dff7b644c33cf36d32ea4d455ab5aa0e72872dba..4c2e31f0b187dc2cbda355ee873c2182e356d510 100644
--- a/pc/devrtc.c
+++ b/pc/devrtc.c
@@ -38,7 +38,6 @@ struct Rtc
 	int	year;
 };
 
-QLock rtclock;	/* mutex on clock operations */
 
 enum{
 	Qrtc = 1,
@@ -140,7 +139,7 @@ _rtctime(void)
 	return rtc2sec(&rtc);
 }
 
-static Lock rtlock;
+static Lock nvrtlock;
 
 long
 rtctime(void)
@@ -148,7 +147,7 @@ rtctime(void)
 	int i;
 	long t, ot;
 
-	ilock(&rtlock);
+	ilock(&nvrtlock);
 
 	/* loop till we get two reads in a row the same */
 	t = _rtctime();
@@ -160,7 +159,7 @@ rtctime(void)
 	}
 	if(i == 100) print("we are boofheads\n");
 
-	iunlock(&rtlock);
+	iunlock(&nvrtlock);
 
 	return t;
 }
@@ -169,7 +168,7 @@ static long
 rtcread(Chan* c, void* buf, long n, vlong off)
 {
 	ulong t;
-	char *a;
+	char *a, *start;
 	ulong offset = off;
 
 	if(c->qid.path & CHDIR)
@@ -177,26 +176,33 @@ rtcread(Chan* c, void* buf, long n, vlong off)
 
 	switch(c->qid.path){
 	case Qrtc:
-		qlock(&rtclock);
 		t = rtctime();
-		qunlock(&rtclock);
 		n = readnum(offset, buf, n, t, 12);
 		return n;
 	case Qnvram:
-		a = buf;
-		if(waserror()){
-			qunlock(&rtclock);
-			nexterror();
-		}
-		qlock(&rtclock);
+		if(n == 0)
+			return 0;
+		if(n > Nvsize)
+			n = Nvsize;
+		a = start = smalloc(n);
+
+		ilock(&nvrtlock);
 		for(t = offset; t < offset + n; t++){
 			if(t >= Nvsize)
 				break;
 			outb(Paddr, Nvoff+t);
 			*a++ = inb(Pdata);
 		}
-		qunlock(&rtclock);
+		iunlock(&nvrtlock);
+
+		if(waserror()){
+			free(start);
+			nexterror();
+		}
+		memmove(buf, start, t - offset);
 		poperror();
+
+		free(start);
 		return t - offset;
 	}
 	error(Ebadarg);
@@ -209,7 +215,7 @@ static long
 rtcwrite(Chan* c, void* buf, long n, vlong off)
 {
 	int t;
-	char *a;
+	char *a, *start;
 	Rtc rtc;
 	ulong secs;
 	uchar bcdclock[Nbcd];
@@ -248,30 +254,39 @@ rtcwrite(Chan* c, void* buf, long n, vlong off)
 		/*
 		 *  write the clock
 		 */
-		qlock(&rtclock);
+		ilock(&nvrtlock);
 		outb(Paddr, Seconds);	outb(Pdata, bcdclock[0]);
 		outb(Paddr, Minutes);	outb(Pdata, bcdclock[1]);
 		outb(Paddr, Hours);	outb(Pdata, bcdclock[2]);
 		outb(Paddr, Mday);	outb(Pdata, bcdclock[3]);
 		outb(Paddr, Month);	outb(Pdata, bcdclock[4]);
 		outb(Paddr, Year);	outb(Pdata, bcdclock[5]);
-		qunlock(&rtclock);
+		iunlock(&nvrtlock);
 		return n;
 	case Qnvram:
-		a = buf;
+		if(n == 0)
+			return 0;
+		if(n > Nvsize)
+			n = Nvsize;
+	
+		start = a = smalloc(n);
 		if(waserror()){
-			qunlock(&rtclock);
+			free(start);
 			nexterror();
 		}
-		qlock(&rtclock);
+		memmove(a, buf, n);
+		poperror();
+
+		ilock(&nvrtlock);
 		for(t = offset; t < offset + n; t++){
 			if(t >= Nvsize)
 				break;
 			outb(Paddr, Nvoff+t);
 			outb(Pdata, *a++);
 		}
-		qunlock(&rtclock);
-		poperror();
+		iunlock(&nvrtlock);
+
+		free(start);
 		return t - offset;
 	}
 	error(Ebadarg);
@@ -414,17 +429,15 @@ sec2rtc(ulong secs, Rtc *rtc)
 	return;
 }
 
-static Lock nvramlock;
-
 uchar
 nvramread(int addr)
 {
 	uchar data;
 
-	lock(&nvramlock);
+	ilock(&nvrtlock);
 	outb(Paddr, addr);
 	data = inb(Pdata);
-	unlock(&nvramlock);
+	iunlock(&nvrtlock);
 
 	return data;
 }
@@ -432,8 +445,8 @@ nvramread(int addr)
 void
 nvramwrite(int addr, uchar data)
 {
-	lock(&nvramlock);
+	ilock(&nvrtlock);
 	outb(Paddr, addr);
 	outb(Pdata, data);
-	unlock(&nvramlock);
+	iunlock(&nvrtlock);
 }
diff --git a/pc/main.c b/pc/main.c
index ffcb6767490870288aaeef1e4a9d699dfd68f96d..05ec5e70a27ba27eef89db2b17f590023c47aea2 100644
--- a/pc/main.c
+++ b/pc/main.c
@@ -431,7 +431,7 @@ confinit(void)
 		 * 4MB on the first Image chunk allocation.
 		 */
 		if(conf.npage*BY2PG < 16*MB)
-			poolsetparam("Image", 0, 0, 4*1024*1024);
+			poolsetparam("Image", 0, 0, 4*1024*1024, nil);
 	}
 	conf.upages = conf.npage - kpages;
 	conf.ialloc = (kpages/2)*BY2PG;
@@ -447,14 +447,14 @@ confinit(void)
 		+ conf.nimage*sizeof(Image)
 		+ conf.nswap
 		+ conf.nswppo*sizeof(Page);
-	poolsetparam("Main", kpages, 0, 0);
+	poolsetparam("Main", kpages, 0, 0, nil);
 	if(!cpuserver){
 		/*
 		 * give terminals lots of image memory, too; the dynamic
 		 * allocation will balance the load properly, hopefully.
 		 * be careful with 32-bit overflow.
 		 */
-		poolsetparam("Image", kpages, 0, 0);
+		poolsetparam("Image", kpages, 0, 0, nil);
 	}
 }
 
diff --git a/port/portfns.h b/port/portfns.h
index 404e9a68c65197ca50f29b0d204d331e3172206d..d8333d9aa3522da0b784af4e99091503115fd04a 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -91,7 +91,7 @@ void		error(char*);
 long		execregs(ulong, ulong, ulong);
 void		exhausted(char*);
 void		exit(int);
-uvlong		fastticks(uvlong*);
+vlong		fastticks(uvlong*);
 int		fault(ulong, int);
 void		fdclose(int, int);
 Chan*		fdtochan(int, int, int, int);
@@ -183,6 +183,7 @@ void		pgrpcpy(Pgrp*, Pgrp*);
 void		pgrpnote(ulong, char*, long, int);
 Pgrp*		pgrptab(int);
 void		pio(Segment *, ulong, ulong, Page **);
+void		poolsetparam(char*, ulong, int, int, void (*)(void*, void*));
 void		poolsummary(void);
 #define		poperror()		up->nerrlab--
 int		postnote(Proc*, int, char*, int);
@@ -294,6 +295,7 @@ void		srvrecover(Chan*, Chan*);
 int		swapcount(ulong);
 int		swapfull(void);
 void		swapinit(void);
+void		syncfastticks(vlong);
 Block*		trimblock(Block*, int, int);
 void		tsleep(Rendez*, int (*)(void*), void*, int);
 void		unbreak(Proc*);