Re: Detect on-die temp sensor for Atom E6xx on amd64

[Kurt Miller]

On Wednesday 30 January 2013 3:49:34 am Mark Kettenis wrote:
> > Date: Tue, 29 Jan 2013 17:35:13 -0500
> > From: Matt Dainty <m...@bodgit-n-scarper.com>
> > 
> > * Christian Weisgerber <na...@mips.inka.de> [2013-01-24 13:03:43]:
> > > I think it's dubious that we match the CPU brand name for this at
> > > all.  Shouldn't this be properly handled with CPUID?
> > 
> > Here's a slightly simpler diff that checks the vendor rather than the
> > CPU brand.
> > 
> > I'm not sure if it's safe to check CPUID regardless of vendor, plus
> > there is the CLFLUSH code in that block as well, I figure that's
> > confined to Intel for a reason?
> 
> Look at the equivalent i386 code.

Looking at the the equivalent i386 code shows that ci_cflushsz is
only set when the vendor is Intel and the cpu features has CFLUSH
set. Also core update sensors are only checked when vendor is
Intel and cpuid_level >= 0x06. The following diff changes amd64
to follow these rules, allows the Atom E6XX sensors to attach and
brings amd64 closer to i386 for these items.

-Kurt

Index: sys/arch/amd64/amd64/identcpu.c
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/identcpu.c,v
retrieving revision 1.43
diff -u -p -r1.43 identcpu.c
--- sys/arch/amd64/amd64/identcpu.c     10 Nov 2012 09:45:05 -0000      1.43
+++ sys/arch/amd64/amd64/identcpu.c     12 Feb 2013 04:21:35 -0000
@@ -506,20 +506,24 @@ identifycpu(struct cpu_info *ci)
                if (ci->ci_feature_sefflags & SEFF0EBX_SMAP)
                        replacesmap();
        }
-       if (!strncmp(mycpu_model, "Intel", 5)) {
-               u_int32_t cflushsz;
+       if (!strcmp(cpu_vendor, "GenuineIntel")) {
+               if (ci->ci_feature_flags & CPUID_CFLUSH) {
+                       u_int32_t cflushsz;
 
-               CPUID(0x01, dummy, cflushsz, dummy, dummy);
-               /* cflush cacheline size is equal to bits 15-8 of ebx * 8 */
-               ci->ci_cflushsz = ((cflushsz >> 8) & 0xff) * 8;
-               CPUID(0x06, val, dummy, dummy, dummy);
-               if (val & 0x1) {
-                       strlcpy(ci->ci_sensordev.xname, ci->ci_dev->dv_xname,
-                           sizeof(ci->ci_sensordev.xname));
-                       ci->ci_sensor.type = SENSOR_TEMP;
-                       sensor_task_register(ci, intelcore_update_sensor, 5);
-                       sensor_attach(&ci->ci_sensordev, &ci->ci_sensor);
-                       sensordev_install(&ci->ci_sensordev);
+                       CPUID(0x01, dummy, cflushsz, dummy, dummy);
+                       /* cflush cacheline size is equal to bits 15-8 of ebx * 
8 */
+                       ci->ci_cflushsz = ((cflushsz >> 8) & 0xff) * 8;
+               }
+               if (cpuid_level >= 0x06) {
+                       CPUID(0x06, val, dummy, dummy, dummy);
+                       if (val & 0x1) {
+                               strlcpy(ci->ci_sensordev.xname, 
ci->ci_dev->dv_xname,
+                               sizeof(ci->ci_sensordev.xname));
+                               ci->ci_sensor.type = SENSOR_TEMP;
+                               sensor_task_register(ci, 
intelcore_update_sensor, 5);
+                               sensor_attach(&ci->ci_sensordev, 
&ci->ci_sensor);
+                               sensordev_install(&ci->ci_sensordev);
+                       }
                }
        }