1 files changed, 52 insertions, 16 deletions

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 5a2bbe0c4fff..01b618e73ecd 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -1078,16 +1078,6 @@ void *xquad_portio;
 EXPORT_SYMBOL(xquad_portio);
 #endif
 
-/*
- * Fall back to non SMP mode after errors.
- *
- */
-static __init void disable_smp(void)
-{
-        cpu_set(0, cpu_sibling_map[0]);
-        cpu_set(0, cpu_core_map[0]);
-}
-
 static void __init smp_boot_cpus(unsigned int max_cpus)
 {
         int apicid, cpu, bit, kicked;
@@ -1100,6 +1090,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
         printk("CPU%d: ", 0);
         print_cpu_info(&cpu_data[0]);
 
+        boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
         boot_cpu_logical_apicid = logical_smp_processor_id();
         x86_cpu_to_apicid[0] = boot_cpu_physical_apicid;
 
@@ -1111,27 +1102,68 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
         cpus_clear(cpu_core_map[0]);
         cpu_set(0, cpu_core_map[0]);
 
-        map_cpu_to_logical_apicid();
-
         /*
          * If we couldn't find an SMP configuration at boot time,
          * get out of here now!
          */
         if (!smp_found_config && !acpi_lapic) {
                 printk(KERN_NOTICE "SMP motherboard not detected.\n");
-                disable_smp();
+                smpboot_clear_io_apic_irqs();
+                phys_cpu_present_map = physid_mask_of_physid(0);
+                if (APIC_init_uniprocessor())
+                        printk(KERN_NOTICE "Local APIC not detected."
+                                           " Using dummy APIC emulation.\n");
+                map_cpu_to_logical_apicid();
+                cpu_set(0, cpu_sibling_map[0]);
+                cpu_set(0, cpu_core_map[0]);
+                return;
+        }
+
+        /*
+         * Should not be necessary because the MP table should list the boot
+         * CPU too, but we do it for the sake of robustness anyway.
+         * Makes no sense to do this check in clustered apic mode, so skip it
+         */
+        if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
+                printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
+                                boot_cpu_physical_apicid);
+                physid_set(hard_smp_processor_id(), phys_cpu_present_map);
+        }
+
+        /*
+         * If we couldn't find a local APIC, then get out of here now!
+         */
+        if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) {
+                printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
+                        boot_cpu_physical_apicid);
+                printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
+                smpboot_clear_io_apic_irqs();
+                phys_cpu_present_map = physid_mask_of_physid(0);
+                cpu_set(0, cpu_sibling_map[0]);
+                cpu_set(0, cpu_core_map[0]);
                 return;
         }
 
+        verify_local_APIC();
+
         /*
          * If SMP should be disabled, then really disable it!
          */
-        if (!max_cpus || (enable_local_apic < 0)) {
-                printk(KERN_INFO "SMP mode deactivated.\n");
-                disable_smp();
+        if (!max_cpus) {
+                smp_found_config = 0;
+                printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
+                smpboot_clear_io_apic_irqs();
+                phys_cpu_present_map = physid_mask_of_physid(0);
+                cpu_set(0, cpu_sibling_map[0]);
+                cpu_set(0, cpu_core_map[0]);
                 return;
         }
 
+        connect_bsp_APIC();
+        setup_local_APIC();
+        map_cpu_to_logical_apicid();
+
+
         setup_portio_remap();
 
         /*
@@ -1212,6 +1244,10 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
         cpu_set(0, cpu_sibling_map[0]);
         cpu_set(0, cpu_core_map[0]);
 
+        smpboot_setup_io_apic();
+
+        setup_boot_APIC_clock();
+
         /*
          * Synchronize the TSC with the AP
          */