[src/trunk]: src/sys/arch/x86/x86 Split TSC calibtration into many small step...

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

details:   https://anonhg.NetBSD.org/src/rev/3c284d1df820
branches:  trunk
changeset: 368944:3c284d1df820
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sun Aug 14 07:49:33 2022 +0000

description:
Split TSC calibtration into many small steps and disable interrupts
for each step. Also add debug messages.

diffstat:

 sys/arch/x86/x86/cpu.c |  36 ++++++++++++++++++++++++++++--------
 1 files changed, 28 insertions(+), 8 deletions(-)

diffs (75 lines):

diff -r 001f3f368722 -r 3c284d1df820 sys/arch/x86/x86/cpu.c
--- a/sys/arch/x86/x86/cpu.c    Sun Aug 14 04:17:09 2022 +0000
+++ b/sys/arch/x86/x86/cpu.c    Sun Aug 14 07:49:33 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu.c,v 1.203 2022/04/01 19:57:22 riastradh Exp $      */
+/*     $NetBSD: cpu.c,v 1.204 2022/08/14 07:49:33 mlelstv Exp $        */
 
 /*
  * Copyright (c) 2000-2020 NetBSD Foundation, Inc.
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.203 2022/04/01 19:57:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.204 2022/08/14 07:49:33 mlelstv Exp $");
 
 #include "opt_ddb.h"
 #include "opt_mpbios.h"                /* for MPDEBUG */
@@ -1336,9 +1336,16 @@
                 */
                if (ci->ci_data.cpu_cc_freq == 0)
                        freq = freq_from_cpuid = cpu_tsc_freq_cpuid(ci);
+               if (freq != 0)
+                       aprint_debug_dev(ci->ci_dev, "TSC freq "
+                           "from CPUID %" PRIu64 " Hz\n", freq);
 #if NHPET > 0
-               if (freq == 0)
+               if (freq == 0) {
                        freq = hpet_tsc_freq();
+                       if (freq != 0)
+                               aprint_debug_dev(ci->ci_dev, "TSC freq "
+                                   "from HPET %" PRIu64 " Hz\n", freq);
+               }
 #endif
                if (freq == 0) {
                        /*
@@ -1348,20 +1355,33 @@
                         */
                        overhead = 0;
                        for (int i = 0; i <= 8; i++) {
+                               const int s = splhigh();
                                t0 = cpu_counter();
                                delay_func(0);
                                t1 = cpu_counter();
+                               splx(s);
                                if (i > 0) {
                                        overhead += (t1 - t0);
                                }
                        }
                        overhead >>= 3;
 
-                       /* Now do the calibration. */
-                       t0 = cpu_counter();
-                       delay_func(100000);
-                       t1 = cpu_counter();
-                       freq = (t1 - t0 - overhead) * 10;
+                       /*
+                        * Now do the calibration.
+                        */
+                       freq = 0;
+                       for (int i = 0; i < 1000; i++) {
+                               const int s = splhigh();
+                               t0 = cpu_counter();
+                               delay_func(100);
+                               t1 = cpu_counter();
+                               splx(s);
+                               freq += t1 - t0 - overhead;
+                       }
+                       freq = freq * 10;
+
+                       aprint_debug_dev(ci->ci_dev, "TSC freq "
+                           "from delay %" PRIu64 " Hz\n", freq);
                }
                if (ci->ci_data.cpu_cc_freq != 0) {
                        freq_from_cpuid = cpu_tsc_freq_cpuid(ci);