x86: apic: Fixmap apic address even if apic disabled

In case if apic were disabled by boot option
we still need read_apic operation. So fixmap
a fake apic area if needed.

[ Impact: fix boot crash ]

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: yinghai@kernel.org
Cc: eswierk@aristanetworks.com
LKML-Reference: <20090511134140.GH4624@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 8 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 0e6543fafb50..07cffc1214cb 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1587,13 +1587,6 @@ void __init init_apic_mappings(void)
         } else
                 apic_phys = mp_lapic_addr;
 
-        /* lets check if we may NOP'ify apic operations */
-        if (!cpu_has_apic) {
-                pr_info("APIC: disable apic facility\n");
-                apic_disable();
-                return;
-        }
-
         /*
          * acpi lapic path already maps that address in
          * acpi_register_lapic_address()
@@ -1602,7 +1595,15 @@ void __init init_apic_mappings(void)
                 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
 
         apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
-                                APIC_BASE, apic_phys);
+                        APIC_BASE, apic_phys);
+
+        /* lets check if we may NOP'ify apic operations */
+        if (!cpu_has_apic) {
+                pr_info("APIC: disable apic facility\n");
+                apic_disable();
+                return;
+        }
+
         /*
          * Fetch the APIC ID of the BSP in case we have a
          * default configuration (or the MP table is broken).