[src/trunk]: src/sys/arch/x86/x86 coretemp(4): Change limits of Tjmax.

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

details:   https://anonhg.NetBSD.org/src/rev/e337ca426e69
branches:  trunk
changeset: 377466:e337ca426e69
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Thu Jul 13 09:12:23 2023 +0000

description:
coretemp(4): Change limits of Tjmax.

 - Change the lower limit from 70 to 60. At least, some BIOSes can change
   the value down to 62.
 - Change the upper limit from 110 to 120. At least, some BIOSes can change
   the value up to 115.
 - Print error message when rdmsr(TEMPERATURE_TARGET) failed.
 - When Tjmax exceeded the limit, print warning message and use the value
   as it is.

diffstat:

 sys/arch/x86/x86/coretemp.c |  41 ++++++++++++++++++++++-------------------
 1 files changed, 22 insertions(+), 19 deletions(-)

diffs (83 lines):

diff -r 0f4a0c9498d3 -r e337ca426e69 sys/arch/x86/x86/coretemp.c
--- a/sys/arch/x86/x86/coretemp.c       Thu Jul 13 08:40:38 2023 +0000
+++ b/sys/arch/x86/x86/coretemp.c       Thu Jul 13 09:12:23 2023 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: coretemp.c,v 1.38 2021/10/07 12:52:27 msaitoh Exp $ */
+/* $NetBSD: coretemp.c,v 1.39 2023/07/13 09:12:23 msaitoh Exp $ */
 
 /*-
  * Copyright (c) 2011 The NetBSD Foundation, Inc.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: coretemp.c,v 1.38 2021/10/07 12:52:27 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: coretemp.c,v 1.39 2023/07/13 09:12:23 msaitoh Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -102,6 +102,10 @@
 
 #define MSR_TEMP_TARGET_READOUT                __BITS(16, 23)
 
+#define TJMAX_DEFAULT          100
+#define TJMAX_LIMIT_LOW                60
+#define TJMAX_LIMIT_HIGH       120
+
 static int     coretemp_match(device_t, cfdata_t, void *);
 static void    coretemp_attach(device_t, device_t, void *);
 static int     coretemp_detach(device_t, int);
@@ -259,16 +263,15 @@ coretemp_tjmax(device_t self)
 {
        struct coretemp_softc *sc = device_private(self);
        struct cpu_info *ci = sc->sc_ci;
+       uint64_t msr;
        uint32_t model, stepping;
-       uint64_t msr;
+       int tjmax;
 
        model = CPUID_TO_MODEL(ci->ci_signature);
        stepping = CPUID_TO_STEPPING(ci->ci_signature);
 
-       /*
-        * Use 100C as the initial value.
-        */
-       sc->sc_tjmax = 100;
+       /* Set the initial value. */
+       sc->sc_tjmax = TJMAX_DEFAULT;
 
        if ((model == 0x0f && stepping >= 2) || (model == 0x0e)) {
                /*
@@ -304,20 +307,20 @@ coretemp_tjmax(device_t self)
                        sc->sc_tjmax = 90;
        } else {
 notee:
-               /*
-                * Attempt to get Tj(max) from IA32_TEMPERATURE_TARGET,
-                * but only consider the interval [70, 110] C as valid.
-                * It is not fully known which CPU models have the MSR.
-                */
-               if (rdmsr_safe(MSR_TEMPERATURE_TARGET, &msr) == EFAULT)
-                       return;
-
-               msr = __SHIFTOUT(msr, MSR_TEMP_TARGET_READOUT);
-
-               if (msr >= 70 && msr <= 110) {
-                       sc->sc_tjmax = msr;
+               /* Attempt to get Tj(max) from IA32_TEMPERATURE_TARGET. */
+               if (rdmsr_safe(MSR_TEMPERATURE_TARGET, &msr) == EFAULT) {
+                       aprint_error_dev(sc->sc_dev,
+                           "Failed to read TEMPERATURE_TARGET MSR. "
+                           "Use the default (%d)\n", sc->sc_tjmax);
                        return;
                }
+
+               tjmax = __SHIFTOUT(msr, MSR_TEMP_TARGET_READOUT);
+               if ((tjmax < TJMAX_LIMIT_LOW) || (tjmax > TJMAX_LIMIT_HIGH))
+                       aprint_error_dev(sc->sc_dev,
+                           "WARNING: Tjmax(%d) might exceeded the limit.\n",
+                           tjmax);
+               sc->sc_tjmax = tjmax;
        }
 }