1 files changed, 16 insertions, 0 deletions

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index d86dbf7e54be..d7b6f7fb4fec 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -274,6 +274,18 @@ static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt)
 
 void __init default_smp_read_mpc_oem(struct mpc_table *mpc) { }
 
+static void __init smp_register_lapic_address(unsigned long address)
+{
+        mp_lapic_addr = address;
+
+        set_fixmap_nocache(FIX_APIC_BASE, address);
+        if (boot_cpu_physical_apicid == -1U) {
+                boot_cpu_physical_apicid  = read_apic_id();
+                apic_version[boot_cpu_physical_apicid] =
+                         GET_APIC_VERSION(apic_read(APIC_LVR));
+        }
+}
+
 static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
 {
         char str[16];
@@ -295,6 +307,10 @@ static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
         if (early)
                 return 1;
 
+        /* Initialize the lapic mapping */
+        if (!acpi_lapic)
+                smp_register_lapic_address(mpc->lapic);
+
         if (mpc->oemptr)
                 x86_init.mpparse.smp_read_mpc_oem(mpc);