3 files changed, 24 insertions, 0 deletions

diff --git a/arch/i386/kernel/cpu/mtrr/main.c b/arch/i386/kernel/cpu/mtrr/main.c
index 0acfb6a5a220..02a2f39e5e0a 100644
--- a/arch/i386/kernel/cpu/mtrr/main.c
+++ b/arch/i386/kernel/cpu/mtrr/main.c
@@ -729,6 +729,17 @@ void mtrr_ap_init(void)
         local_irq_restore(flags);
 }
 
+/**
+ * Save current fixed-range MTRR state of the BSP
+ */
+void mtrr_save_state(void)
+{
+        if (smp_processor_id() == 0)
+                mtrr_save_fixed_ranges(NULL);
+        else
+                smp_call_function_single(0, mtrr_save_fixed_ranges, NULL, 1, 1);
+}
+
 static int __init mtrr_init_finialize(void)
 {
         if (!mtrr_if)
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 7c1dbef399cd..f14d93351a82 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -58,6 +58,7 @@
 #include <mach_wakecpu.h>
 #include <smpboot_hooks.h>
 #include <asm/vmi.h>
+#include <asm/mtrr.h>
 
 /* Set if we find a B stepping CPU */
 static int __devinitdata smp_b_stepping;
@@ -815,6 +816,12 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
         unsigned short nmi_high = 0, nmi_low = 0;
 
         /*
+         * Save current MTRR state in case it was changed since early boot
+         * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
+         */
+        mtrr_save_state();
+
+        /*
          * We can't use kernel_thread since we must avoid to
          * reschedule the child.
          */
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 14724be48bec..ddc392bee243 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -944,6 +944,12 @@ int __cpuinit __cpu_up(unsigned int cpu)
                 return -ENOSYS;
         }
 
+        /*
+         * Save current MTRR state in case it was changed since early boot
+         * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
+         */
+        mtrr_save_state();
+
         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
         /* Boot it! */
         err = do_boot_cpu(cpu, apicid);