src/patches/suse-2.6.27.31/patches.arch/x2APIC_PATCH_15_of_41_2d7a66d02e11af9ab8e16c76d22767e622b4e3d7

   1 From: Suresh Siddha <suresh.b.siddha@intel.com>
   2 Subject: x64, x2apic/intr-remap: Interrupt-remapping and x2apic support, fix
   3 References: fate #303948 and fate #303984
   4 Patch-Mainline: queued for .28
   5 Commit-ID: 2d7a66d02e11af9ab8e16c76d22767e622b4e3d7
   6
   7 Signed-off-by: Thomas Renninger <trenn@suse.de>
   8
   9 Yinghai Lu wrote:
  10
  11 > Setting APIC routing to physical flat
  12 > Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (0 vs 4)
  13 > Pid: 1, comm: swapper Not tainted 2.6.26-rc9-tip-01763-g74f94b1-dirty #320
  14 >
  15 > Call Trace:
  16 >  [<ffffffff80a21505>] ? set_cpu_sibling_map+0x38c/0x3bd
  17 >  [<ffffffff80245215>] ? read_xapic_id+0x25/0x3e
  18 >  [<ffffffff80e5a2c3>] ? verify_local_APIC+0x139/0x1b9
  19 >  [<ffffffff80245215>] ? read_xapic_id+0x25/0x3e
  20 >  [<ffffffff80e589af>] ? native_smp_prepare_cpus+0x224/0x2e9
  21 >  [<ffffffff80e4881a>] ? kernel_init+0x64/0x341
  22 >  [<ffffffff8022a439>] ? child_rip+0xa/0x11
  23 >  [<ffffffff80e487b6>] ? kernel_init+0x0/0x341
  24 >  [<ffffffff8022a42f>] ? child_rip+0x0/0x11
  25 >
  26 >
  27 > guess read_apic_id changing cuase some problem...
  28
  29 genapic's read_apic_id() returns the actual apic id extracted from
  30 the APIC_ID register. And in some cases like UV, read_apic_id()
  31 returns completely different values from APIC ID register.
  32
  33 Use the native apic register read, rather than genapic read_apic_id()
  34 in verify_local_APIC()
  35
  36 And also, lapic_suspend() should also use native apic register read.
  37
  38 Reported-by: Yinghai Lu <yhlu.kernel@gmail.com>
  39 Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
  40 Cc: "akpm@linux-foundation.org" <akpm@linux-foundation.org>
  41 Cc: "arjan@linux.intel.com" <arjan@linux.intel.com>
  42 Cc: "andi@firstfloor.org" <andi@firstfloor.org>
  43 Cc: "ebiederm@xmission.com" <ebiederm@xmission.com>
  44 Cc: "jbarnes@virtuousgeek.org" <jbarnes@virtuousgeek.org>
  45 Cc: "steiner@sgi.com" <steiner@sgi.com>
  46 Cc: "jeremy@goop.org" <jeremy@goop.org>
  47 Signed-off-by: Ingo Molnar <mingo@elte.hu>
  48
  49 ---
  50  arch/x86/kernel/apic_64.c |    6 +++---
  51  1 file changed, 3 insertions(+), 3 deletions(-)
  52
  53 Index: linux-2.6.26/arch/x86/kernel/apic_64.c
  54 ===================================================================
  55 --- linux-2.6.26.orig/arch/x86/kernel/apic_64.c
  56 +++ linux-2.6.26/arch/x86/kernel/apic_64.c
  57 @@ -629,10 +629,10 @@ int __init verify_local_APIC(void)
  58         /*
  59          * The ID register is read/write in a real APIC.
  60          */
  61 -       reg0 = read_apic_id();
  62 +       reg0 = apic_read(APIC_ID);
  63         apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
  64         apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
  65 -       reg1 = read_apic_id();
  66 +       reg1 = apic_read(APIC_ID);
  67         apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
  68         apic_write(APIC_ID, reg0);
  69         if (reg1 != (reg0 ^ APIC_ID_MASK))
  70 @@ -1136,7 +1136,7 @@ static int lapic_suspend(struct sys_devi
  71
  72         maxlvt = lapic_get_maxlvt();
  73
  74 -       apic_pm_state.apic_id = read_apic_id();
  75 +       apic_pm_state.apic_id = apic_read(APIC_ID);
  76         apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
  77         apic_pm_state.apic_ldr = apic_read(APIC_LDR);
  78         apic_pm_state.apic_dfr = apic_read(APIC_DFR);