5 files changed, 28 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);
diff --git a/include/asm-i386/mtrr.h b/include/asm-i386/mtrr.h
index 02a41b99bd7e..7e9c7ccbdcfe 100644
--- a/include/asm-i386/mtrr.h
+++ b/include/asm-i386/mtrr.h
@@ -70,6 +70,7 @@ struct mtrr_gentry
 /*  The following functions are for use by other drivers  */
 # ifdef CONFIG_MTRR
 extern void mtrr_save_fixed_ranges(void *);
+extern void mtrr_save_state(void);
 extern int mtrr_add (unsigned long base, unsigned long size,
                      unsigned int type, char increment);
 extern int mtrr_add_page (unsigned long base, unsigned long size,
@@ -81,6 +82,7 @@ extern void mtrr_ap_init(void);
 extern void mtrr_bp_init(void);
 #  else
 #define mtrr_save_fixed_ranges(arg) do {} while (0)
+#define mtrr_save_state() do {} while (0)
 static __inline__ int mtrr_add (unsigned long base, unsigned long size,
                                 unsigned int type, char increment)
 {
diff --git a/include/asm-x86_64/mtrr.h b/include/asm-x86_64/mtrr.h
index 1b326cbb9305..b557c486bef8 100644
--- a/include/asm-x86_64/mtrr.h
+++ b/include/asm-x86_64/mtrr.h
@@ -139,10 +139,12 @@ struct mtrr_gentry32
 extern void mtrr_ap_init(void);
 extern void mtrr_bp_init(void);
 extern void mtrr_save_fixed_ranges(void *);
+extern void mtrr_save_state(void);
 #else
 #define mtrr_ap_init() do {} while (0)
 #define mtrr_bp_init() do {} while (0)
 #define mtrr_save_fixed_ranges(arg) do {} while (0)
+#define mtrr_save_state() do {} while (0)
 #endif
 
 #endif /* __KERNEL__ */