1 files changed, 37 insertions, 9 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 7af0f88a4163..84e83de54575 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -58,6 +58,7 @@ unsigned int mtrr_usage_table[MTRR_MAX_VAR_RANGES];
 static DEFINE_MUTEX(mtrr_mutex);
 
 u64 size_or_mask, size_and_mask;
+static bool mtrr_aps_delayed_init;
 
 static struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM];
 
@@ -163,7 +164,10 @@ static void ipi_handler(void *info)
         if (data->smp_reg != ~0U) {
                 mtrr_if->set(data->smp_reg, data->smp_base,
                              data->smp_size, data->smp_type);
-        } else {
+        } else if (mtrr_aps_delayed_init) {
+                /*
+                 * Initialize the MTRRs inaddition to the synchronisation.
+                 */
                 mtrr_if->set_all();
         }
 
@@ -265,6 +269,8 @@ set_mtrr(unsigned int reg, unsigned long base, unsigned long size, mtrr_type typ
          */
         if (reg != ~0U)
                 mtrr_if->set(reg, base, size, type);
+        else if (!mtrr_aps_delayed_init)
+                mtrr_if->set_all();
 
         /* Wait for the others */
         while (atomic_read(&data.count))
@@ -721,9 +727,7 @@ void __init mtrr_bp_init(void)
 
 void mtrr_ap_init(void)
 {
-        unsigned long flags;
-
-        if (!mtrr_if || !use_intel())
+        if (!use_intel() || mtrr_aps_delayed_init)
                 return;
         /*
          * Ideally we should hold mtrr_mutex here to avoid mtrr entries
@@ -738,11 +742,7 @@ void mtrr_ap_init(void)
          *   2. cpu hotadd time. We let mtrr_add/del_page hold cpuhotplug
          *      lock to prevent mtrr entry changes
          */
-        local_irq_save(flags);
-
-        mtrr_if->set_all();
-
-        local_irq_restore(flags);
+        set_mtrr(~0U, 0, 0, 0);
 }
 
 /**
@@ -753,6 +753,34 @@ void mtrr_save_state(void)
         smp_call_function_single(0, mtrr_save_fixed_ranges, NULL, 1);
 }
 
+void set_mtrr_aps_delayed_init(void)
+{
+        if (!use_intel())
+                return;
+
+        mtrr_aps_delayed_init = true;
+}
+
+/*
+ * MTRR initialization for all AP's
+ */
+void mtrr_aps_init(void)
+{
+        if (!use_intel())
+                return;
+
+        set_mtrr(~0U, 0, 0, 0);
+        mtrr_aps_delayed_init = false;
+}
+
+void mtrr_bp_restore(void)
+{
+        if (!use_intel())
+                return;
+
+        mtrr_if->set_all();
+}
+
 static int __init mtrr_init_finialize(void)
 {
         if (!mtrr_if)