1 files changed, 13 insertions, 2 deletions

diff --git a/arch/x86/kernel/mpparse_64.c b/arch/x86/kernel/mpparse_64.c
index 8bf0ca03ac8e..4336c0fc3b81 100644
--- a/arch/x86/kernel/mpparse_64.c
+++ b/arch/x86/kernel/mpparse_64.c
@@ -86,7 +86,7 @@ static int __init mpf_checksum(unsigned char *mp, int len)
         return sum & 0xFF;
 }
 
-static void __cpuinit MP_processor_info (struct mpc_config_processor *m)
+static void __cpuinit MP_processor_info(struct mpc_config_processor *m)
 {
         int cpu;
         cpumask_t tmp_map;
@@ -123,7 +123,18 @@ static void __cpuinit MP_processor_info (struct mpc_config_processor *m)
                 cpu = 0;
         }
         bios_cpu_apicid[cpu] = m->mpc_apicid;
-        x86_cpu_to_apicid[cpu] = m->mpc_apicid;
+        /*
+         * We get called early in the the start_kernel initialization
+         * process when the per_cpu data area is not yet setup, so we
+         * use a static array that is removed after the per_cpu data
+         * area is created.
+         */
+        if (x86_cpu_to_apicid_ptr) {
+                u8 *x86_cpu_to_apicid = (u8 *)x86_cpu_to_apicid_ptr;
+                x86_cpu_to_apicid[cpu] = m->mpc_apicid;
+        } else {
+                per_cpu(x86_cpu_to_apicid, cpu) = m->mpc_apicid;
+        }
 
         cpu_set(cpu, cpu_possible_map);
         cpu_set(cpu, cpu_present_map);