1 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 6cbd15625dce..12948316e6a6 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -310,6 +310,13 @@ void __init setup_arch(char **cmdline_p)
          * we are rounding upwards:
          */
         end_pfn = e820_end_of_ram();
+        /* update e820 for memory not covered by WB MTRRs */
+        mtrr_bp_init();
+        if (mtrr_trim_uncached_memory(end_pfn)) {
+                e820_register_active_regions(0, 0, -1UL);
+                end_pfn = e820_end_of_ram();
+        }
+
         num_physpages = end_pfn;
 
         check_efer();