Move i386 to timecounters. This is more or less the same code as amd64.

The "lapic" timer is ripped out since it wasn't actually a lapic timer,
but a hacked up tsc timer with some synchronization for MP. There is no
tsc timer right now since they are very unreliable on MP systems, systems
with apm, and systems that change the cpu clock. Which basically means
every modern machine out there. We're running with the i8259 timer now.

deraadt@ ok

7 files changed, 139 insertions, 70 deletions

diff --git a/sys/arch/i386/conf/files.i386 b/sys/arch/i386/conf/files.i386
index 9a344bbbac5..54a34506343 100644
--- a/sys/arch/i386/conf/files.i386
+++ b/sys/arch/i386/conf/files.i386
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.i386,v 1.155 2007/03/19 03:02:09 marco Exp $
+#	$OpenBSD: files.i386,v 1.156 2007/03/19 09:29:33 art Exp $
 #
 # new style config file for i386 architecture
 #
@@ -30,7 +30,6 @@ file	arch/i386/i386/longrun.c	!small_kernel & i586_cpu
 file	arch/i386/i386/mem.c
 file	arch/i386/i386/i686_mem.c	mtrr
 file	arch/i386/i386/k6_mem.c		mtrr
-file	arch/i386/i386/microtime.s
 file	arch/i386/i386/p4tcc.c		!small_kernel & i686_cpu
 file	arch/i386/i386/pmap.c
 file	arch/i386/i386/powernow.c	!small_kernel & i586_cpu
diff --git a/sys/arch/i386/i386/apm.c b/sys/arch/i386/i386/apm.c
index aca6a6a1443..404c19d0204 100644
--- a/sys/arch/i386/i386/apm.c
+++ b/sys/arch/i386/i386/apm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: apm.c,v 1.73 2007/02/27 15:16:30 marco Exp $	*/
+/*	$OpenBSD: apm.c,v 1.74 2007/03/19 09:29:33 art Exp $	*/
 
 /*-
  * Copyright (c) 1998-2001 Michael Shalayeff. All rights reserved.
@@ -351,7 +351,7 @@ apm_resume(struct apm_softc *sc, struct apmregs *regs)
 	/* they say that some machines may require reinitializing the clock */
 	initrtclock();
 
-	inittodr(time.tv_sec);
+	inittodr(time_second);
 	/* lower bit in cx means pccard was powered down */
 	dopowerhooks(PWR_RESUME);
 	apm_record_event(sc, regs->bx);
@@ -464,7 +464,7 @@ apm_handle_event(struct apm_softc *sc, struct apmregs *regs)
 		break;
 	case APM_UPDATE_TIME:
 		DPRINTF(("update time, please\n"));
-		inittodr(time.tv_sec);
+		inittodr(time_second);
 		apm_record_event(sc, regs->bx);
 		break;
 	case APM_CRIT_SUSPEND_REQ:
diff --git a/sys/arch/i386/i386/lapic.c b/sys/arch/i386/i386/lapic.c
index bd74f8d5f10..3c05f8f3aec 100644
--- a/sys/arch/i386/i386/lapic.c
+++ b/sys/arch/i386/i386/lapic.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lapic.c,v 1.13 2007/02/20 21:15:01 tom Exp $	*/
+/*	$OpenBSD: lapic.c,v 1.14 2007/03/19 09:29:33 art Exp $	*/
 /* $NetBSD: lapic.c,v 1.1.2.8 2000/02/23 06:10:50 sommerfeld Exp $ */
 
 /*-
@@ -44,6 +44,7 @@
 #include <sys/user.h>
 #include <sys/systm.h>
 #include <sys/device.h>
+#include <sys/timetc.h>
 
 #include <uvm/uvm_extern.h>
 
@@ -259,8 +260,7 @@ extern void (*initclock_func)(void); /* XXX put in header file */
  * We're actually using the IRQ0 timer.  Hmm.
  */
 void
-lapic_calibrate_timer(ci)
-	struct cpu_info *ci;
+lapic_calibrate_timer(struct cpu_info *ci)
 {
 	unsigned int starttick, tick1, tick2, endtick;
 	unsigned int startapic, apic1, apic2, endapic;
@@ -386,7 +386,6 @@ lapic_calibrate_timer(ci)
 		 * for all our timing needs..
 		 */
 		delay_func = lapic_delay;
-		microtime_func = lapic_microtime;
 		initclock_func = lapic_initclocks;
 	}
 }
@@ -396,8 +395,7 @@ lapic_calibrate_timer(ci)
  */
 
 void
-lapic_delay(usec)
-	int usec;
+lapic_delay(int usec)
 {
 	int32_t tick, otick;
 	int64_t deltat;		/* XXX may want to be 64bit */
@@ -432,6 +430,7 @@ i386_ipi_microset(struct cpu_info *ci)
 	ci->ci_tscbase = rdtsc();
 }
 
+#if 0
 /*
  * XXX need to make work correctly on other than cpu 0.
  */
@@ -457,6 +456,7 @@ lapic_microtime(tv)
 
 	*tv = now;
 }
+#endif
 
 /*
  * XXX the following belong mostly or partly elsewhere..
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 9a144fb849e..3343744a8ca 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.379 2007/02/21 19:34:25 deraadt Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.380 2007/03/19 09:29:33 art Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -256,7 +256,6 @@ void (*setperf_setup)(struct cpu_info *);
 int setperf_prio = 0;		/* for concurrent handlers */
 
 void (*delay_func)(int) = i8254_delay;
-void (*microtime_func)(struct timeval *) = i8254_microtime;
 void (*initclock_func)(void) = i8254_initclocks;
 void (*update_cpuspeed)(void) = NULL;
 
@@ -3288,9 +3287,14 @@ cpu_reset()
 }
 
 void
-cpu_initclocks()
+cpu_initclocks(void)
 {
 	(*initclock_func)();
+
+	if (initclock_func == i8254_initclocks)
+		i8254_inittimecounter();
+	else
+		i8254_inittimecounter_simple();
 }
 
 void
diff --git a/sys/arch/i386/include/_types.h b/sys/arch/i386/include/_types.h
index cef2a372f29..52cbef65faa 100644
--- a/sys/arch/i386/include/_types.h
+++ b/sys/arch/i386/include/_types.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: _types.h,v 1.4 2007/02/20 21:15:01 tom Exp $	*/
+/*	$OpenBSD: _types.h,v 1.5 2007/03/19 09:29:33 art Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -117,5 +117,6 @@ typedef	void *			__wctype_t;
 /* Feature test macros */
 #define __HAVE_CPUINFO
 #define __HAVE_MUTEX
+#define __HAVE_TIMECOUNTER
 
 #endif	/* _I386__TYPES_H_ */
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index a066cbea0bb..faebea52539 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.88 2007/03/15 10:22:29 art Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.89 2007/03/19 09:29:33 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -237,30 +237,15 @@ extern void need_resched(struct cpu_info *);
  */
 extern void (*delay_func)(int);
 struct timeval;
-extern void (*microtime_func)(struct timeval *);
 
 #define	DELAY(x)		(*delay_func)(x)
 #define delay(x)		(*delay_func)(x)
-#define microtime(tv)		(*microtime_func)(tv)
 
 #if defined(I586_CPU) || defined(I686_CPU)
 /*
  * High resolution clock support (Pentium only)
  */
 void	calibrate_cyclecounter(void);
-#ifndef	HZ
-extern u_quad_t pentium_base_tsc;
-#define CPU_CLOCKUPDATE()						\
-	do {								\
-		if (cpuspeed) {						\
-			__asm __volatile("cli\n"			\
-					 "rdtsc\n"			\
-					 : "=A" (pentium_base_tsc)	\
-					 : );				\
-			__asm __volatile("sti"); 			\
-		}							\
-	} while (0)
-#endif
 #endif
 
 /*
@@ -357,8 +342,10 @@ void	initrtclock(void);
 void	startrtclock(void);
 void	rtcdrain(void *);
 void	i8254_delay(int);
-void	i8254_microtime(struct timeval *);
 void	i8254_initclocks(void);
+void	i8254_inittimecounter(void);
+void	i8254_inittimecounter_simple(void);
+
 
 /* est.c */
 #if !defined(SMALL_KERNEL) && defined(I686_CPU)
diff --git a/sys/arch/i386/isa/clock.c b/sys/arch/i386/isa/clock.c
index 0fd1090e682..f3b34498b3a 100644
--- a/sys/arch/i386/isa/clock.c
+++ b/sys/arch/i386/isa/clock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clock.c,v 1.38 2006/12/20 17:50:40 gwk Exp $	*/
+/*	$OpenBSD: clock.c,v 1.39 2007/03/19 09:29:33 art Exp $	*/
 /*	$NetBSD: clock.c,v 1.39 1996/05/12 23:11:54 mycroft Exp $	*/
 
 /*-
@@ -92,6 +92,8 @@ WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <sys/kernel.h>
 #include <sys/device.h>
 #include <sys/timeout.h>
+#include <sys/timetc.h>
+#include <sys/mutex.h>
 
 #include <machine/cpu.h>
 #include <machine/intr.h>
@@ -105,7 +107,6 @@ WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <i386/isa/timerreg.h>
 
 void	spinwait(int);
-void	findcpuspeed(void);
 int	clockintr(void *);
 int	gettick(void);
 int	rtcget(mc_todregs *);
@@ -125,6 +126,19 @@ int cpuspeed;
 int clock_broken_latch;
 #endif
 
+/* Timecounter on the i8254 */
+uint32_t i8254_lastcount;
+uint32_t i8254_offset;
+int i8254_ticked;
+u_int i8254_get_timecount(struct timecounter *tc);
+u_int i8254_simple_get_timecount(struct timecounter *tc);
+
+static struct timecounter i8254_timecounter = {
+	i8254_get_timecount, NULL, ~0u, TIMER_FREQ, "i8254", 0, NULL
+};
+struct mutex timer_mutex = MUTEX_INITIALIZER(IPL_HIGH);
+u_long rtclock_tval;
+
 #define	SECMIN	((unsigned)60)			/* seconds per minute */
 #define	SECHOUR	((unsigned)(60*SECMIN))		/* seconds per hour */
 
@@ -161,8 +175,6 @@ startrtclock(void)
 {
 	int s;
 
-	findcpuspeed();		/* use the clock (while it's free)
-					to find the cpu speed */
 	initrtclock();
 
 	/* Check diagnostic status */
@@ -190,12 +202,17 @@ rtcdrain(void *v)
 void
 initrtclock(void)
 {
+	mtx_enter(&timer_mutex);
+
 	/* initialize 8253 clock */
 	outb(TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
 
 	/* Correct rounding will buy us a better precision in timekeeping */
 	outb(IO_TIMER1, TIMER_DIV(hz) % 256);
 	outb(IO_TIMER1, TIMER_DIV(hz) / 256);
+
+	rtclock_tval = TIMER_DIV(hz);
+	mtx_leave(&timer_mutex);
 }
 
 int
@@ -203,6 +220,15 @@ clockintr(void *arg)
 {
 	struct clockframe *frame = arg;		/* not strictly necessary */
 
+	if (timecounter->tc_get_timecount == i8254_get_timecount) {
+		if (i8254_ticked) {
+			i8254_ticked = 0;
+		} else {
+			i8254_offset += rtclock_tval;
+			i8254_lastcount = 0;
+		}
+	}
+
 	hardclock(frame);
 	return (1);
 }
@@ -233,6 +259,11 @@ gettick(void)
 		int v1, v2, v3;
 		int w1, w2, w3;
 
+		/*
+		 * Don't lock the mutex in this case, clock_broken_latch
+		 * CPUs don't do MP anyway.
+		 */
+
 		disable_intr();
 
 		v1 = inb(TIMER_CNTR0);
@@ -279,14 +310,18 @@ gettick(void)
 #endif
 	{
 		u_char lo, hi;
+		u_long ef;
 
+		mtx_enter(&timer_mutex);
+		ef = read_eflags();
 		disable_intr();
 		/* Select counter 0 and latch it. */
 		outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
 		lo = inb(TIMER_CNTR0);
 		hi = inb(TIMER_CNTR0);
 
-		enable_intr();
+		write_eflags(ef);
+		mtx_leave(&timer_mutex);
 		return ((hi << 8) | lo);
 	}
 }
@@ -350,31 +385,6 @@ i8254_delay(int n)
 	}
 }
 
-unsigned int delaycount;	/* calibrated loop variable (1 millisecond) */
-
-#define FIRST_GUESS   0x2000
-
-void
-findcpuspeed(void)
-{
-	int i;
-	int remainder;
-
-	/* Put counter in count down mode */
-	outb(TIMER_MODE, TIMER_SEL0 | TIMER_16BIT | TIMER_RATEGEN);
-	outb(TIMER_CNTR0, 0xff);
-	outb(TIMER_CNTR0, 0xff);
-	for (i = FIRST_GUESS; i; i--)
-		;
-	/* Read the value left in the counter */
-	remainder = gettick();
-	/*
-	 * Formula for delaycount is:
-	 *  (loopcount * timer clock speed) / (counter ticks * 1000)
-	 */
-	delaycount = (FIRST_GUESS * TIMER_DIV(1000)) / (0xffff-remainder);
-}
-
 #if defined(I586_CPU) || defined(I686_CPU)
 void
 calibrate_cyclecounter(void)
@@ -537,10 +547,14 @@ clock_expandyear(int clockyear)
 void
 inittodr(time_t base)
 {
+	struct timespec ts;
 	mc_todregs rtclk;
 	struct clock_ymdhms dt;
 	int s;
 
+
+	ts.tv_nsec = 0;
+
 	/*
 	 * We mostly ignore the suggested time and go for the RTC clock time
 	 * stored in the CMOS RAM.  If the time can't be obtained from the
@@ -555,8 +569,6 @@ inittodr(time_t base)
 		base = 17*SECYR + 186*SECDAY + SECDAY/2;
 	}
 
-	time.tv_usec = 0;
-
 	s = splclock();
 	if (rtcget(&rtclk)) {
 		splx(s);
@@ -592,24 +604,26 @@ inittodr(time_t base)
 		}
 	}
 
-	time.tv_sec = clock_ymdhms_to_secs(&dt) + tz.tz_minuteswest * 60;
+	ts.tv_sec = clock_ymdhms_to_secs(&dt) + tz.tz_minuteswest * 60;
 	if (tz.tz_dsttime)
-		time.tv_sec -= 3600;
+		ts.tv_sec -= 3600;
 
-	if (base < time.tv_sec - 5*SECYR)
+	if (base < ts.tv_sec - 5*SECYR)
 		printf("WARNING: file system time much less than clock time\n");
-	else if (base > time.tv_sec + 5*SECYR) {
+	else if (base > ts.tv_sec + 5*SECYR) {
 		printf("WARNING: clock time much less than file system time\n");
 		printf("WARNING: using file system time\n");
 		goto fstime;
 	}
 
+	tc_setclock(&ts);
 	timeset = 1;
 	return;
 
 fstime:
+	ts.tv_sec = base;
+	tc_setclock(&ts);
 	timeset = 1;
-	time.tv_sec = base;
 	printf("WARNING: CHECK AND RESET THE DATE!\n");
 }
 
@@ -640,7 +654,7 @@ resettodr(void)
 	diff = tz.tz_minuteswest * 60;
 	if (tz.tz_dsttime)
 		diff -= 3600;
-	clock_secs_to_ymdhms(time.tv_sec - diff, &dt);
+	clock_secs_to_ymdhms(time_second - diff, &dt);
 
 	rtclk[MC_SEC] = dectohexdec(dt.dt_sec);
 	rtclk[MC_MIN] = dectohexdec(dt.dt_min);
@@ -666,3 +680,67 @@ setstatclockrate(int arg)
 	else
 		mc146818_write(NULL, MC_REGA, MC_BASE_32_KHz | MC_RATE_1024_Hz);
 }
+
+void
+i8254_inittimecounter(void)
+{
+	tc_init(&i8254_timecounter);
+}
+
+/*
+ * If we're using lapic to drive hardclock, we can use a simpler
+ * algorithm for the i8254 timecounters.
+ */
+void
+i8254_inittimecounter_simple(void)
+{
+	u_long tval = 0x8000;
+
+	i8254_timecounter.tc_get_timecount = i8254_simple_get_timecount;
+	i8254_timecounter.tc_counter_mask = 0x7fff;
+
+	i8254_timecounter.tc_frequency = TIMER_FREQ;
+
+	mtx_enter(&timer_mutex);
+	outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT);
+	outb(IO_TIMER1, tval & 0xff);
+	outb(IO_TIMER1, tval >> 8);
+
+	rtclock_tval = tval;
+	mtx_leave(&timer_mutex);
+
+	tc_init(&i8254_timecounter);
+}
+
+u_int
+i8254_simple_get_timecount(struct timecounter *tc)
+{
+	return (rtclock_tval - gettick());
+}
+
+u_int
+i8254_get_timecount(struct timecounter *tc)
+{
+	u_char hi, lo;
+	u_int count;
+	u_long ef;
+
+	ef = read_eflags();
+	disable_intr();
+
+	outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
+	lo = inb(TIMER_CNTR0);
+	hi = inb(TIMER_CNTR0);
+
+	count = rtclock_tval - ((hi << 8) | lo);
+
+	if (count < i8254_lastcount) {
+		i8254_ticked = 1;
+		i8254_offset += rtclock_tval;
+	}
+	i8254_lastcount = count;
+	count += i8254_offset;
+	write_eflags(ef);
+
+	return (count);
+}