8 files changed, 88 insertions(+), 1 deletions(-)

M ip/devip.c
M pc/archgeneric.c
M pc/clock.c
M pc/dat.h
M pc/fns.h
M pc/i8253.c
M port/devcons.c
M port/portfns.h

@@ 520,7 520,7 @@ ipread(Chan *ch, void *a, long n, vlong off)
 	Conv *c;
 	Proto *x;
 	char *buf, *p;
-	long m, rv;
+	long rv;
 	Fs *f;
 	ulong offset = off;
 

@@ 17,6 17,8 @@ nop(void)
 }
 
 void (*coherence)(void) = nop;
+void cycletimerinit(void);
+uvlong cycletimer(uvlong*);
 
 PCArch* arch;
 extern PCArch* knownarch[];


@@ 32,6 34,8 @@ PCArch archgeneric = {
 	i8259enable,				/* intrenable */
 
 	i8253enable,				/* clockenable */
+
+	i8253read,				/* read the standard timer */
 };
 
 typedef struct {


@@ 185,6 189,12 @@ archinit(void)
 			arch->intrenable = archgeneric.intrenable;
 	}
 
+	/* pick the better timer */
+	if(X86FAMILY(m->cpuidax) >= 5){
+		cycletimerinit();
+		arch->fastclock = cycletimer;
+	}
+
 	/*
 	 * Decide whether to use copy-on-reference (386 and mp).
 	 */


@@ 194,3 204,31 @@ archinit(void)
 	if(X86FAMILY(m->cpuidax) == 6 /*&& conf.nmach > 1*/)
 		coherence = wbflush;
 }
+
+static uvlong fasthz;
+
+void
+cycletimerinit(void)
+{
+	fasthz = 1000000LL*m->cpumhz;
+}
+
+/*
+ *  return the most precice clock we have
+ */
+uvlong
+cycletimer(uvlong *hz)
+{
+	uvlong tsc;
+
+	rdmsr(0x10, (vlong*)&tsc);
+	if(hz != nil)
+		*hz = fasthz;
+	return tsc;
+}
+
+uvlong
+fastticks(uvlong *hz)
+{
+	return (*arch->fastclock)(hz);
+}

@@ 88,3 88,4 @@ microdelay(int microsecs)
 		microsecs = 1;
 	aamloop(microsecs);
 }
+

@@ 221,6 221,7 @@ struct PCArch
 	int	(*intrenable)(int, int, Irqctl*);
 
 	void	(*clockenable)(void);
+	uvlong	(*fastclock)(uvlong*);
 };
 
 /*

@@ 36,6 36,7 @@ void	i8042auxenable(void (*)(int, int));
 void	i8042reset(void);
 void	i8253init(int);
 void	i8253enable(void);
+uvlong	i8253read(uvlong*);
 void	i8259init(void);
 int	i8259enable(int, int, Irqctl*);
 void	idle(void);

@@ 98,3 98,17 @@ i8253enable(void)
 {
 	intrenable(VectorCLOCK, clockintr, 0, BUSUNKNOWN);
 }
+
+Lock i8253lock;
+
+/*
+ *  return time elapsed since clock start in
+ *  10ths of nanoseconds
+ */
+uvlong
+i8253read(uvlong *hz)
+{
+	if(hz)
+		*hz = HZ;
+	return m->ticks;
+}

@@ 345,6 345,7 @@ enum{
 	Qconsctl,
 	Qcputime,
 	Qdrivers,
+	Qfastclock,
 	Qhz,
 	Qkey,
 	Qhostdomain,


@@ 373,6 374,7 @@ static Dirtab consdir[]={
 	"consctl",	{Qconsctl},	0,		0220,
 	"cputime",	{Qcputime},	6*NUMSIZE,	0444,
 	"drivers",	{Qdrivers},	0,		0644,
+	"fastclock",	{Qfastclock},	4*NUMSIZE,	0444,
 	"hostdomain",	{Qhostdomain},	DOMLEN,		0664,
 	"hostowner",	{Qhostowner},	NAMELEN,	0664,
 	"hz",		{Qhz},		NUMSIZE,	0666,


@@ 401,6 403,21 @@ seconds(void)
 }
 
 int
+readvlnum(ulong off, char *buf, ulong n, uvlong val, int size)
+{
+	char tmp[64];
+
+	snprint(tmp, sizeof(tmp), "%*.0ulld", size-1, val);
+	tmp[size-1] = ' ';
+	if(off >= size)
+		return 0;
+	if(off+n > size)
+		n = size-off;
+	memmove(buf, tmp+off, n);
+	return n;
+}
+
+int
 readnum(ulong off, char *buf, ulong n, ulong val, int size)
 {
 	char tmp[64];


@@ 515,6 532,7 @@ consread(Chan *c, void *buf, long n, vlong off)
 	char *cbuf = buf;
 	int ch, i, k, id, eol;
 	vlong offset = off;
+	uvlong ticks, fasthz;
 
 	if(n <= 0)
 		return n;


@@ 623,6 641,19 @@ consread(Chan *c, void *buf, long n, vlong off)
 		memmove(buf, tmp+k, n);
 		return n;
 
+	case Qfastclock:
+		ticks = fastticks(&fasthz);
+
+		k = offset;
+		if(k >= 4*NUMSIZE)
+			return 0;
+		if(k+n > 4*NUMSIZE)
+			n = 4*NUMSIZE - k;
+		readvlnum(0, tmp, 2*NUMSIZE, ticks, 2*NUMSIZE);
+		readvlnum(0, tmp+2*NUMSIZE, 2*NUMSIZE, fasthz, 2*NUMSIZE);
+		memmove(buf, tmp+k, n);
+		return n;
+
 	case Qkey:
 		return keyread(buf, n, offset);
 

@@ 91,6 91,7 @@ void		error(char*);
 long		execregs(ulong, ulong, ulong);
 void		exhausted(char*);
 void		exit(int);
+uvlong		fastticks(uvlong*);
 int		fault(ulong, int);
 void		fdclose(int, int);
 Chan*		fdtochan(int, int, int, int);