2 files changed, 19 insertions, 6 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 509bd3d9eacd..cb7d3b6a80eb 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -379,6 +379,7 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
                              unsigned long *size, mtrr_type *type)
 {
         unsigned int mask_lo, mask_hi, base_lo, base_hi;
+        unsigned int tmp, hi;
 
         rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);
         if ((mask_lo & 0x800) == 0) {
@@ -392,8 +393,23 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
         rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi);
 
         /* Work out the shifted address mask. */
-        mask_lo = size_or_mask | mask_hi << (32 - PAGE_SHIFT)
-            | mask_lo >> PAGE_SHIFT;
+        tmp = mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT;
+        mask_lo = size_or_mask | tmp;
+        /* Expand tmp with high bits to all 1s*/
+        hi = fls(tmp);
+        if (hi > 0) {
+                tmp |= ~((1<<(hi - 1)) - 1);
+
+                if (tmp != mask_lo) {
+                        static int once = 1;
+
+                        if (once) {
+                                printk(KERN_INFO "mtrr: your BIOS has set up an incorrect mask, fixing it up.\n");
+                                once = 0;
+                        }
+                        mask_lo = tmp;
+                }
+        }
 
         /* This works correctly if size is a power of two, i.e. a
            contiguous range. */
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 6f23969c8faf..b117d7f8a564 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -1496,11 +1496,8 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 
         /* kvm/qemu doesn't have mtrr set right, don't trim them all */
         if (!highest_pfn) {
-                if (!kvm_para_available()) {
-                        printk(KERN_WARNING
+                WARN(!kvm_para_available(), KERN_WARNING
                                 "WARNING: strange, CPU MTRRs all blank?\n");
-                        WARN_ON(1);
-                }
                 return 0;
         }