x86, hotplug: The first online processor saves the MTRR state

Ask the first online CPU to save mtrr instead of asking BSP. BSP could be
offline when mtrr_save_state() is called.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-12-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 6b96110bb0c3..e4c1a4184531 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -695,11 +695,16 @@ void mtrr_ap_init(void)
 }
 
 /**
- * Save current fixed-range MTRR state of the BSP
+ * Save current fixed-range MTRR state of the first cpu in cpu_online_mask.
  */
 void mtrr_save_state(void)
 {
-        smp_call_function_single(0, mtrr_save_fixed_ranges, NULL, 1);
+        int first_cpu;
+
+        get_online_cpus();
+        first_cpu = cpumask_first(cpu_online_mask);
+        smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1);
+        put_online_cpus();
 }
 
 void set_mtrr_aps_delayed_init(void)