x86: unify uniq_io_apic_id

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/x86/kernel/mpparse_32.c b/arch/x86/kernel/mpparse_32.c
index 7feafa5040d8..a50a31331f97 100644
--- a/arch/x86/kernel/mpparse_32.c
+++ b/arch/x86/kernel/mpparse_32.c
@@ -814,17 +814,29 @@ static int mp_find_ioapic(int gsi)
         }
 
         printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
-
         return -1;
 }
 
 static u8 uniq_ioapic_id(u8 id)
 {
+#ifdef CONFIG_X86_32
         if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
             !APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
                 return io_apic_get_unique_id(nr_ioapics, id);
         else
                 return id;
+#else
+        int i;
+        DECLARE_BITMAP(used, 256);
+        bitmap_zero(used, 256);
+        for (i = 0; i < nr_ioapics; i++) {
+                struct mpc_config_ioapic *ia = &mp_ioapics[i];
+                __set_bit(ia->mpc_apicid, used);
+        }
+        if (!test_bit(id, used))
+                return id;
+        return find_first_zero_bit(used, 256);
+#endif
 }
 
 void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)