[src/nathanw_sa]: src/sys/arch/alpha/alpha Assorted microtime fixes (similar ...

[sommerfeld <sommerfeld%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/98776329730d
branches:  nathanw_sa
changeset: 504688:98776329730d
user:      sommerfeld <sommerfeld%NetBSD.org@localhost>
date:      Sun May 27 13:53:25 2001 +0000

description:
Assorted microtime fixes (similar to fixes I made yesterday when
porting this code to i386mp branch):

 - call microset() early on each cpu so that calls to microtime()
before the first clock interrupt don't return trash.  this manifested
itself as garbage runtimes in "ps" for kernel threads.
 - avoid races between hardclock updating "time" and microset on a
different cpu reading it by adding a "microset_time" global which is
initialized from "time" on the primary cpu.
 - call microset every hz ticks, not every hz+1 (cosmetic)

diffstat:

 sys/arch/alpha/alpha/clock.c     |  285 +++++++++++++++++++++++++++++++++++++++
 sys/arch/alpha/alpha/microtime.c |  209 ++++++++++++++++++++++++++++
 2 files changed, 494 insertions(+), 0 deletions(-)

diffs (truncated from 502 to 300 lines):

diff -r 5ea9bf2038e8 -r 98776329730d sys/arch/alpha/alpha/clock.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/arch/alpha/alpha/clock.c      Sun May 27 13:53:25 2001 +0000
@@ -0,0 +1,285 @@
+/* $NetBSD: clock.c,v 1.31.4.2 2001/05/27 13:53:25 sommerfeld Exp $ */
+
+/*
+ * Copyright (c) 1988 University of Utah.
+ * Copyright (c) 1992, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * the Systems Programming Group of the University of Utah Computer
+ * Science Department and Ralph Campbell.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *     This product includes software developed by the University of
+ *     California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * from: Utah Hdr: clock.c 1.18 91/01/21
+ *
+ *     @(#)clock.c     8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/cdefs.h>                 /* RCS ID & Copyright macro defns */
+
+__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.31.4.2 2001/05/27 13:53:25 sommerfeld Exp $");
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/sched.h>
+
+#include <dev/clock_subr.h>
+
+#include <machine/autoconf.h>
+#include <machine/cpuconf.h>
+
+#include <dev/dec/clockvar.h>
+
+#include "opt_clock_compat_osf1.h"
+#include "opt_ntp.h"
+
+#define MINYEAR 1998 /* "today" */
+#ifdef CLOCK_COMPAT_OSF1
+/*
+ * According to OSF/1's /usr/sys/include/arch/alpha/clock.h,
+ * the console adjusts the RTC years 13..19 to 93..99 and
+ * 20..40 to 00..20. (historical reasons?)
+ * DEC Unix uses an offset to the year to stay outside
+ * the dangerous area for the next couple of years.
+ */
+#define UNIX_YEAR_OFFSET 52 /* 41=>1993, 12=>2064 */
+#else
+#define UNIX_YEAR_OFFSET 0
+#endif
+
+struct device *clockdev;
+const struct clockfns *clockfns;
+int clockinitted;
+
+void
+clockattach(dev, fns)
+       struct device *dev;
+       const struct clockfns *fns;
+{
+
+       /*
+        * Just bookkeeping.
+        */
+       printf("\n");
+
+       if (clockfns != NULL)
+               panic("clockattach: multiple clocks");
+       clockdev = dev;
+       clockfns = fns;
+}
+
+/*
+ * Machine-dependent clock routines.
+ *
+ * Startrtclock restarts the real-time clock, which provides
+ * hardclock interrupts to kern_clock.c.
+ *
+ * Inittodr initializes the time of day hardware which provides
+ * date functions.  Its primary function is to use some file
+ * system information in case the hardare clock lost state.
+ *
+ * Resettodr restores the time of day hardware after a time change.
+ */
+
+/*
+ * Start the real-time and statistics clocks. Leave stathz 0 since there
+ * are no other timers available.
+ */
+void
+cpu_initclocks()
+{
+       if (clockfns == NULL)
+               panic("cpu_initclocks: no clock attached");
+
+       tick = 1000000 / hz;    /* number of microseconds between interrupts */
+       tickfix = 1000000 - (hz * tick);
+       if (tickfix) {
+               int ftp;
+
+               ftp = min(ffs(tickfix), ffs(hz));
+               tickfix >>= (ftp - 1);
+               tickfixinterval = hz >> (ftp - 1);
+        }
+
+       /*
+        * Establish the clock interrupt; it's a special case.
+        *
+        * We establish the clock interrupt this late because if
+        * we do it at clock attach time, we may have never been at
+        * spl0() since taking over the system.  Some versions of
+        * PALcode save a clock interrupt, which would get delivered
+        * when we spl0() in autoconf.c.  If established the clock
+        * interrupt handler earlier, that interrupt would go to
+        * hardclock, which would then fall over because p->p_stats
+        * isn't set at that time.
+        */
+       platform.clockintr = hardclock;
+       schedhz = 16;
+
+       /*
+        * Get the clock started.
+        */
+       (*clockfns->cf_init)(clockdev);
+}
+
+/*
+ * We assume newhz is either stathz or profhz, and that neither will
+ * change after being set up above.  Could recalculate intervals here
+ * but that would be a drag.
+ */
+void
+setstatclockrate(newhz)
+       int newhz;
+{
+
+       /* nothing we can do */
+}
+
+/*
+ * Initialze the time of day register, based on the time base which is, e.g.
+ * from a filesystem.  Base provides the time to within six months,
+ * and the time of year clock (if any) provides the rest.
+ */
+void
+inittodr(base)
+       time_t base;
+{
+       struct clocktime ct;
+       int year;
+       struct clock_ymdhms dt;
+       time_t deltat;
+       int badbase;
+
+       if (base < (MINYEAR-1970)*SECYR) {
+               printf("WARNING: preposterous time in file system");
+               /* read the system clock anyway */
+               base = (MINYEAR-1970)*SECYR;
+               badbase = 1;
+       } else
+               badbase = 0;
+
+       (*clockfns->cf_get)(clockdev, base, &ct);
+#ifdef DEBUG
+       printf("readclock: %d/%d/%d/%d/%d/%d", ct.year, ct.mon, ct.day,
+              ct.hour, ct.min, ct.sec);
+#endif
+       clockinitted = 1;
+
+       year = 1900 + UNIX_YEAR_OFFSET + ct.year;
+       if (year < 1970)
+               year += 100;
+       /* simple sanity checks (2037 = time_t overflow) */
+       if (year < MINYEAR || year > 2037 ||
+           ct.mon < 1 || ct.mon > 12 || ct.day < 1 ||
+           ct.day > 31 || ct.hour > 23 || ct.min > 59 || ct.sec > 59) {
+               /*
+                * Believe the time in the file system for lack of
+                * anything better, resetting the TODR.
+                */
+               time.tv_sec = base;
+               if (!badbase) {
+                       printf("WARNING: preposterous clock chip time\n");
+                       resettodr();
+               }
+               goto bad;
+       }
+
+       dt.dt_year = year;
+       dt.dt_mon = ct.mon;
+       dt.dt_day = ct.day;
+       dt.dt_hour = ct.hour;
+       dt.dt_min = ct.min;
+       dt.dt_sec = ct.sec;
+       time.tv_sec = clock_ymdhms_to_secs(&dt);
+#ifdef DEBUG
+       printf("=>%ld (%d)\n", time.tv_sec, base);
+#endif
+       microset_time = time;
+       microset(curcpu(), NULL);
+
+       if (!badbase) {
+               /*
+                * See if we gained/lost two or more days;
+                * if so, assume something is amiss.
+                */
+               deltat = time.tv_sec - base;
+               if (deltat < 0)
+                       deltat = -deltat;
+               if (deltat < 2 * SECDAY)
+                       return;
+               printf("WARNING: clock %s %ld days",
+                   time.tv_sec < base ? "lost" : "gained",
+                   (long)deltat / SECDAY);
+       }
+bad:
+       printf(" -- CHECK AND RESET THE DATE!\n");
+}
+
+/*
+ * Reset the TODR based on the time value; used when the TODR
+ * has a preposterous value and also when the time is reset
+ * by the stime system call.  Also called when the TODR goes past
+ * TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
+ * to wrap the TODR around.
+ */
+void
+resettodr()
+{
+       struct clock_ymdhms dt;
+       struct clocktime ct;
+
+       if (!clockinitted)
+               return;
+
+       microset_time = time;
+#if defined(MULTIPROCESSOR)
+       alpha_multicast_ipi(cpus_running, ALPHA_IPI_MICROSET);
+#endif 
+       microset(curcpu(), NULL);
+       
+       clock_secs_to_ymdhms(time.tv_sec, &dt);
+
+       /* rt clock wants 2 digits */
+       ct.year = (dt.dt_year - UNIX_YEAR_OFFSET) % 100;
+       ct.mon = dt.dt_mon;
+       ct.day = dt.dt_day;
+       ct.hour = dt.dt_hour;
+       ct.min = dt.dt_min;
+       ct.sec = dt.dt_sec;
+       ct.dow = dt.dt_wday;
+#ifdef DEBUG
+       printf("setclock: %d/%d/%d/%d/%d/%d\n", ct.year, ct.mon, ct.day,
+              ct.hour, ct.min, ct.sec);
+#endif
+
+       (*clockfns->cf_set)(clockdev, &ct);
+}
diff -r 5ea9bf2038e8 -r 98776329730d sys/arch/alpha/alpha/microtime.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/arch/alpha/alpha/microtime.c  Sun May 27 13:53:25 2001 +0000
@@ -0,0 +1,209 @@
+/* $NetBSD: microtime.c,v 1.3.6.2 2001/05/27 13:53:25 sommerfeld Exp $ */
+
+/*-
+ * Copyright (c) 2001 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation