1. 26 Aug, 2009 3 commits
    • Yinghai Lu's avatar
      x86: Fix vSMP boot crash · 295594e9
      Yinghai Lu authored
      2.6.31-rc7 does not boot on vSMP systems:
      
      [    8.501108] CPU31: Thermal monitoring enabled (TM1)
      [    8.501127] CPU 31 MCA banks SHD:2 SHD:3 SHD:5 SHD:6 SHD:8
      [    8.650254] CPU31: Intel(R) Xeon(R) CPU           E5540  @ 2.53GHz stepping 04
      [    8.710324] Brought up 32 CPUs
      [    8.713916] Total of 32 processors activated (162314.96 BogoMIPS).
      [    8.721489] ERROR: parent span is not a superset of domain->span
      [    8.727686] ERROR: domain->groups does not contain CPU0
      [    8.733091] ERROR: groups don't span domain->span
      [    8.737975] ERROR: domain->cpu_power not set
      [    8.742416]
      
      Ravikiran Thirumalai bisected it to:
      
      | commit 2759c328
      | x86: don't call read_apic_id if !cpu_has_apic
      
      The problem is that on vSMP systems the CPUID derived
      initial-APICIDs are overlapping - so we need to fall
      back on hard_smp_processor_id() which reads the local
      APIC.
      
      Both come from the hardware (influenced by firmware
      though) so it's a tough call which one to trust.
      
      Doing the quirk expresses the vSMP property properly
      and also does not affect other systems, so we go for
      this solution instead of a revert.
      Reported-and-Tested-by: default avatarRavikiran Thirumalai <kiran@scalex86.org>
      Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: Shai Fultheim <shai@scalex86.org>
      Cc: Suresh Siddha <suresh.b.siddha@intel.com>
      LKML-Reference: <4A944D3C.5030100@kernel.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      295594e9
    • H. Peter Anvin's avatar
      x86, xen: Initialize cx to suppress warning · 7adb4df4
      H. Peter Anvin authored
      Initialize cx before calling xen_cpuid(), in order to suppress the
      "may be used uninitialized in this function" warning.
      Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      Cc: Jeremy Fitzhardinge <jeremy@goop.org>
      7adb4df4
    • Jeremy Fitzhardinge's avatar
      x86, xen: Suppress WP test on Xen · d560bc61
      Jeremy Fitzhardinge authored
      Xen always runs on CPUs which properly support WP enforcement in
      privileged mode, so there's no need to test for it.
      
      This also works around a crash reported by Arnd Hannemann, though I
      think its just a band-aid for that case.
      Reported-by: default avatarArnd Hannemann <hannemann@nets.rwth-aachen.de>
      Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      d560bc61
  2. 25 Aug, 2009 11 commits
  3. 24 Aug, 2009 26 commits