1 files changed, 8 insertions, 26 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 894aa97f071..ad8c75b9e45 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -241,28 +241,13 @@ static int modern_apic(void)
 }
 
 /*
- * bare function to substitute write operation
- * and it's _that_ fast :)
- */
-static void native_apic_write_dummy(u32 reg, u32 v)
-{
-        WARN_ON_ONCE((cpu_has_apic || !disable_apic));
-}
-
-static u32 native_apic_read_dummy(u32 reg)
-{
-        WARN_ON_ONCE((cpu_has_apic && !disable_apic));
-        return 0;
-}
-
-/*
- * right after this call apic->write/read doesn't do anything
- * note that there is no restore operation it works one way
+ * right after this call apic become NOOP driven
+ * so apic->write/read doesn't do anything
  */
 void apic_disable(void)
 {
-        apic->read = native_apic_read_dummy;
-        apic->write = native_apic_write_dummy;
+        pr_info("APIC: switched to apic NOOP\n");
+        apic = &apic_noop;
 }
 
 void native_apic_wait_icr_idle(void)
@@ -459,7 +444,7 @@ static void lapic_timer_setup(enum clock_event_mode mode,
                 v = apic_read(APIC_LVTT);
                 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
                 apic_write(APIC_LVTT, v);
-                apic_write(APIC_TMICT, 0xffffffff);
+                apic_write(APIC_TMICT, 0);
                 break;
         case CLOCK_EVT_MODE_RESUME:
                 /* Nothing to do here */
@@ -1392,14 +1377,11 @@ void __init enable_IR_x2apic(void)
         unsigned long flags;
         struct IO_APIC_route_entry **ioapic_entries = NULL;
         int ret, x2apic_enabled = 0;
-        int dmar_table_init_ret = 0;
+        int dmar_table_init_ret;
 
-#ifdef CONFIG_INTR_REMAP
         dmar_table_init_ret = dmar_table_init();
-        if (dmar_table_init_ret)
-                pr_debug("dmar_table_init() failed with %d:\n",
-                                dmar_table_init_ret);
-#endif
+        if (dmar_table_init_ret && !x2apic_supported())
+                return;
 
         ioapic_entries = alloc_ioapic_entries();
         if (!ioapic_entries) {