From 48f43f725a88ff7d921ad6b029c668d2bf4d8c8f Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 1 Jul 1999 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1999-07-01

---
 alphapc/dat.h     |   1 +
 alphapc/trap.c    |   1 +
 carrera/dat.h     |   1 +
 carrera/trap.c    |   2 +
 mpc/dat.h         |   1 +
 mpc/trap.c        |   1 +
 pc/dat.h          |   1 +
 pc/fns.h          |   1 -
 pc/trap.c         |   5 +-
 port/devintrts.c  | 134 ++++++++++++++++++++++++++++++++++++++++++++++
 port/devns16552.c |  39 +-------------
 port/portfns.h    |   1 +
 12 files changed, 146 insertions(+), 42 deletions(-)
 create mode 100644 port/devintrts.c

diff --git a/alphapc/dat.h b/alphapc/dat.h
index 9ed070a0ce6d1dbea8e5cdbc73dae598a697cd2c..166d03eeab19d3c115f37a8fb0581c66f2ff4adf 100644
--- a/alphapc/dat.h
+++ b/alphapc/dat.h
@@ -148,6 +148,7 @@ struct Mach
 	ulong	cpuhz;			/* hwrpb->cfreq */
 	ulong	pcclast;
 	uvlong	fastclock;
+	vlong	intrts;			/* time stamp of last interrupt */
 
 	int	pfault;
 	int	cs;
diff --git a/alphapc/trap.c b/alphapc/trap.c
index 60029acb520d2de46b379a0a85cf4a5952f33f46..e986ae165f8906a7fa52f19209a0f8e94b810580 100644
--- a/alphapc/trap.c
+++ b/alphapc/trap.c
@@ -41,6 +41,7 @@ trap(Ureg *ur)
 	char buf[ERRLEN];
 	int user, x;
 
+	m->intrts = fastticks(nil);
 	user = ur->status&UMODE;
 
 	if(user){
diff --git a/carrera/dat.h b/carrera/dat.h
index 3b68a1117ef64bd154a52935b7248521d84cd0e1..d14b4ee3f10777abba5e9c23a80e738ceb197249 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -117,6 +117,7 @@ struct Mach
 	ulong	fairness;		/* for runproc */
 	ulong	lastcyclecount;
 	uvlong	fastclock;
+	vlong	intrts;			/* time stamp of last interrupt */
 	int	flushmmu;		/* make current proc flush it's mmu state */
 
 	int	pfault;
diff --git a/carrera/trap.c b/carrera/trap.c
index b1a23bbf3af6d2760acc220868fe8e250ef4bbd0..752ea0f3b9897e3703c999482171c27b6d08b3cc 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -196,6 +196,8 @@ trap(Ureg *ur)
 	int user, cop, x, fpchk;
 	char buf[2*ERRLEN], buf1[ERRLEN], *fpexcep;
 
+	m->intrts = fastticks(nil);
+
 	/*
 	 * Retry failed probes of legal addresses from tstbadvaddr
 	 * workaround for the R4400 >2.3
diff --git a/mpc/dat.h b/mpc/dat.h
index 55321fc5f28aca2b170578eed636a222dc837e6e..8512b4616dce1d8e4ddea76eb2298b6d298e13de 100644
--- a/mpc/dat.h
+++ b/mpc/dat.h
@@ -140,6 +140,7 @@ struct Mach
 	int	load;
 	int	intr;
 	vlong	fastclock;		/* last sampled value */
+	vlong	intrts;			/* time stamp of last interrupt */
 	int	flushmmu;		/* make current proc flush it's mmu state */
 
 	/* MUST BE LAST */
diff --git a/mpc/trap.c b/mpc/trap.c
index 39a0644ac22d3ddca11c2bae6acba1a9b5e0486d..8ce9d828a6b7c775f7fe25081e33a56fbde3909b 100644
--- a/mpc/trap.c
+++ b/mpc/trap.c
@@ -152,6 +152,7 @@ trap(Ureg *ur)
 	int ecode;
 	static struct {int callsched;} c = {1};
 
+	m->intrts = fastticks(nil);
 	ecode = (ur->cause >> 8) & 0xff;
 	if(ecode < 0 || ecode >= 0x1F)
 		ecode = 0x1F;
diff --git a/pc/dat.h b/pc/dat.h
index 6bb941028209254916bbee1857cdfb333d22cdd0..1cfc12ba3531be282a435b23c07d69b57c2425a9 100644
--- a/pc/dat.h
+++ b/pc/dat.h
@@ -171,6 +171,7 @@ struct Mach
 	int	load;
 	int	intr;
 	vlong	fastclock;		/* last sampled value */
+	vlong	intrts;			/* time stamp of last interrupt */
 	int	flushmmu;		/* make current proc flush it's mmu state */
 
 	ulong	spuriousintr;
diff --git a/pc/fns.h b/pc/fns.h
index 2aa9baa6ae59b814f065aae075464127a2307147..e09aa4bd2cb9312e7468a209ad58b0cb235ade81 100644
--- a/pc/fns.h
+++ b/pc/fns.h
@@ -95,7 +95,6 @@ void	procsetup(Proc*);
 void	putcr3(ulong);
 void	putcr4(ulong);
 void	rdmsr(int, vlong*);
-long	readintrts(void*, int);
 void	screeninit(void);
 int	screenprint(char*, ...);			/* debugging */
 void	(*screenputs)(char*, int);
diff --git a/pc/trap.c b/pc/trap.c
index 2926d4ea52329cf809955e2c4b72231392a74c2a..e678cc9d6ac098bc9fce2bbd1beac004d8d7adc3 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -15,9 +15,6 @@ static void fault386(Ureg*, void*);
 static Lock vctllock;
 static Vctl *vctl[256];
 
-/* interrupt timestamps, l.s fills intrts each interupt */
-uvlong	intrts;
-
 void
 intrenable(int irq, void (*f)(Ureg*, void*), void* a, int tbdf)
 {
@@ -175,6 +172,7 @@ trap(Ureg* ureg)
 	Vctl *ctl, *v;
 	Mach *mach;
 
+	m->intrts = fastticks(nil);
 	user = 0;
 	if((ureg->cs & 0xFFFF) == UESEL){
 		user = 1;
@@ -375,7 +373,6 @@ fault386(Ureg* ureg, void*)
 	read = !(ureg->ecode & 2);
 	insyscall = up->insyscall;
 	up->insyscall = 1;
-	spllo();
 	n = fault(addr, read);
 	if(n < 0){
 		if(!user){
diff --git a/port/devintrts.c b/port/devintrts.c
new file mode 100644
index 0000000000000000000000000000000000000000..6ff3551825355827dfdb416e05cb9c1ed3499fff
--- /dev/null
+++ b/port/devintrts.c
@@ -0,0 +1,134 @@
+/*
+ */
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+
+enum {
+	Qdir,
+	Qintrts,
+};
+
+static Dirtab intrtsdir[] = {
+	"intrts",	{ Qintrts, 0 },		0,	0666,
+};
+
+void (*saveintrts)(void) = nil;
+
+/* interrupt timestamps, trap() fills intrts each interrupt */
+uvlong	intrts;
+static	struct {
+	Lock;
+	int	vno;		/* vector to save timestamps for */
+	int	n;		/* number of valid timestamps in ts[] */
+	uvlong	ts[128];	/* time stamps */
+} tsalloc;
+
+/* called with interrupts off by interrupt routine */
+void
+_saveintrts(void)
+{
+	lock(&tsalloc);
+	if(tsalloc.n < nelem(tsalloc.ts))
+		tsalloc.ts[tsalloc.n++] = m->intrts;
+	unlock(&tsalloc);
+}
+
+/* read interrupt timestamps */
+static long
+readintrts(void *buf, int n)
+{
+	n /= sizeof(uvlong);
+	if(n <= 0)
+		return 0;
+	ilock(&tsalloc);
+	if(n > tsalloc.n)
+		n = tsalloc.n;
+	memmove(buf, tsalloc.ts, n*sizeof(uvlong));
+	tsalloc.n = 0;
+	iunlock(&tsalloc);
+	return n*sizeof(uvlong);
+}
+
+
+static void
+intrtsreset(void)
+{
+	saveintrts = _saveintrts;
+}
+
+static Chan*
+intrtsattach(char* spec)
+{
+	return devattach('Z', spec);	/* everything good was taken */
+}
+
+int
+intrtswalk(Chan* c, char* name)
+{
+	return devwalk(c, name, intrtsdir, nelem(intrtsdir), devgen);
+}
+
+static void
+intrtsstat(Chan* c, char* dp)
+{
+	devstat(c, dp, intrtsdir, nelem(intrtsdir), devgen);
+}
+
+static Chan*
+intrtsopen(Chan* c, int omode)
+{
+	return devopen(c, omode, intrtsdir, nelem(intrtsdir), devgen);
+}
+
+static void
+intrtsclose(Chan*)
+{
+}
+
+static long
+intrtsread(Chan* c, void* a, long n, vlong)
+{
+	switch(c->qid.path & ~CHDIR){
+
+	case Qdir:
+		return devdirread(c, a, n, intrtsdir, nelem(intrtsdir), devgen);
+
+	case Qintrts:
+		return readintrts(a, n);
+	}
+
+	error(Eperm);
+	return 0;
+}
+
+static long
+intrtswrite(Chan*, void*, long, vlong)
+{
+	error(Eperm);
+	return 0;
+}
+
+Dev intrtsdevtab = {
+	'Z',
+	"intrts",
+
+	intrtsreset,
+	devinit,
+	intrtsattach,
+	devclone,
+	intrtswalk,
+	intrtsstat,
+	intrtsopen,
+	devcreate,
+	intrtsclose,
+	intrtsread,
+	devbread,
+	intrtswrite,
+	devbwrite,
+	devremove,
+	devwstat,
+};
diff --git a/port/devns16552.c b/port/devns16552.c
index 5edbf0f9f77f233df49d713e1c034b51b525397b..d7a1cc32d28d3b5644c1a1c5003f367e9383bfdf 100644
--- a/port/devns16552.c
+++ b/port/devns16552.c
@@ -149,41 +149,6 @@ struct Uartalloc {
 
 void ns16552intr(int);
 
-/* interrupt timestamps, l.s fills intrts each interupt */
-uvlong	intrts;
-static	struct {
-	Lock;
-	int	vno;		/* vector to save timestamps for */
-	int	n;		/* number of valid timestamps in ts[] */
-	uvlong	ts[128];	/* time stamps */
-} tsalloc;
-
-/* called with interrupts off by interrupt routine */
-static void
-savets(void)
-{
-	lock(&tsalloc);
-	if(tsalloc.n < nelem(tsalloc.ts))
-		tsalloc.ts[tsalloc.n++] = intrts;
-	unlock(&tsalloc);
-}
-
-/* read interrupt timestamps */
-long
-readintrts(void *buf, int n)
-{
-	n /= sizeof(uvlong);
-	if(n <= 0)
-		return 0;
-	ilock(&tsalloc);
-	if(n > tsalloc.n)
-		n = tsalloc.n;
-	memmove(buf, tsalloc.ts, n*sizeof(uvlong));
-	tsalloc.n = 0;
-	iunlock(&tsalloc);
-	return n*sizeof(uvlong);
-}
-
 /*
  *  pick up architecture specific routines and definitions
  */
@@ -713,8 +678,8 @@ ns16552intr(int dev)
 			}
 	 		if (ch & Dcdc) {
 				l = ch & Dcd;
-				if(l == 0 && p->dcd != 0 && p->dcdts)
-					savets();
+				if(l == 0 && p->dcd != 0 && p->dcdts && saveintrts != nil)
+					(*saveintrts)();
 				if(p->hup_dcd && p->dcd && !l){
 					ilock(&p->rlock);
 					p->dohup = 1;
diff --git a/port/portfns.h b/port/portfns.h
index 4ab6393a6e8365b0c604d32a8db65350ab81b428..9e0e5dbfe250eb9d3a98c892965d775b96d62d7c 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -266,6 +266,7 @@ long		rtctime(void);
 void		runlock(RWlock*);
 Proc*		runproc(void);
 void		savefpregs(FPsave*);
+void		(*saveintrts)(void);
 void		sched(void);
 void		scheddump(void);
 void		schedinit(void);