[src/trunk]: src/sys/arch/x86/acpi As all reported P-state failures so far ha...

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

details:   https://anonhg.NetBSD.org/src/rev/e213e638291b
branches:  trunk
changeset: 757295:e213e638291b
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Tue Aug 24 10:29:53 2010 +0000

description:
As all reported P-state failures so far have centered around the status-
check (today it was christos@' laptop), follow Linux and disable this rather
expensive sanity-check for the time being. A hypothesis about the cause of
the failures relates to the absence of cross-CPU coordination in the current
implementation.

diffstat:

 sys/arch/x86/acpi/acpi_cpu_md.c |  63 ++++++++++++++++------------------------
 1 files changed, 25 insertions(+), 38 deletions(-)

diffs (121 lines):

diff -r 0371a7ff8bad -r e213e638291b sys/arch/x86/acpi/acpi_cpu_md.c
--- a/sys/arch/x86/acpi/acpi_cpu_md.c   Tue Aug 24 08:41:24 2010 +0000
+++ b/sys/arch/x86/acpi/acpi_cpu_md.c   Tue Aug 24 10:29:53 2010 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_md.c,v 1.32 2010/08/24 07:28:00 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_md.c,v 1.33 2010/08/24 10:29:53 jruoho Exp $ */
 
 /*-
  * Copyright (c) 2010 Jukka Ruohonen <jruohonen%iki.fi@localhost>
@@ -27,7 +27,7 @@
  * SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_md.c,v 1.32 2010/08/24 07:28:00 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_md.c,v 1.33 2010/08/24 10:29:53 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -48,6 +48,8 @@
 #include <dev/pci/pcivar.h>
 #include <dev/pci/pcidevs.h>
 
+#define ACPICPU_P_STATE_STATUS 0
+
 /*
  * AMD families 10h and 11h.
  */
@@ -417,13 +419,24 @@
 
        (void)memset(&msr, 0, sizeof(struct acpicpu_pstate));
 
-       if ((sc->sc_flags & ACPICPU_FLAG_P_FIDVID) != 0)
-               msr.ps_flags = ACPICPU_FLAG_P_FIDVID;
-
        switch (cpu_vendor) {
 
        case CPUVENDOR_IDT:
        case CPUVENDOR_INTEL:
+
+               /*
+                * If the so-called Turbo Boost is present,
+                * the P0-state is always the "turbo state".
+                *
+                * For discussion, see:
+                *
+                *      Intel Corporation: Intel Turbo Boost Technology
+                *      in Intel Core(tm) Microarchitectures (Nehalem)
+                *      Based Processors. White Paper, November 2008.
+                */
+               if ((sc->sc_flags & ACPICPU_FLAG_P_TURBO) != 0)
+                       sc->sc_pstate[0].ps_flags |= ACPICPU_FLAG_P_TURBO;
+
                msr.ps_control_addr = MSR_PERF_CTL;
                msr.ps_control_mask = __BITS(0, 15);
 
@@ -433,6 +446,9 @@
 
        case CPUVENDOR_AMD:
 
+               if ((sc->sc_flags & ACPICPU_FLAG_P_FIDVID) != 0)
+                       msr.ps_flags |= ACPICPU_FLAG_P_FIDVID;
+
                family = CPUID2FAMILY(ci->ci_signature);
 
                if (family == 0xf)
@@ -494,26 +510,6 @@
                i++;
        }
 
-       /*
-        * When the state is P0 and Turbo Boost has been
-        * detected, we need to skip the status check as
-        * BIOS may not report right comparison values for
-        * the IA32_PERF_STATUS register. Note that this
-        * issue is specific to Intel. For discussion, see:
-        *
-        *      Intel Corporation: Intel Turbo Boost Technology
-        *      in Intel Core(tm) Microarchitectures (Nehalem)
-        *      Based Processors. White Paper, November 2008.
-        */
-       if (cpu_vendor != CPUVENDOR_INTEL)
-               return 0;
-
-       if ((sc->sc_flags & ACPICPU_FLAG_P_TURBO) == 0)
-               return 0;
-
-       if (sc->sc_pstate[1].ps_freq + 1 == sc->sc_pstate[0].ps_freq)
-               sc->sc_pstate[0].ps_flags |= ACPICPU_FLAG_P_TURBO;
-
        return 0;
 }
 
@@ -584,24 +580,15 @@
        xc = xc_broadcast(0, (xcfunc_t)x86_msr_xcall, &msr, NULL);
        xc_wait(xc);
 
-       if (__predict_false(ps->ps_status == 0))
-               goto out;
-
-       if (__predict_false(ps->ps_status_addr == 0))
-               goto out;
-
-       if ((ps->ps_flags & ACPICPU_FLAG_P_TURBO) != 0)
-               goto out;
+       if (ACPICPU_P_STATE_STATUS == 0) {
+               DELAY(ps->ps_latency);
+               return 0;
+       }
 
        xc = xc_broadcast(0, (xcfunc_t)acpicpu_md_pstate_status, ps, &rv);
        xc_wait(xc);
 
        return rv;
-
-out:
-       DELAY(ps->ps_latency);
-
-       return 0;
 }
 
 static void