Merge branch 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / cpu / mtrr / generic.c

diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 509bd3d9eacd28da737ade7a365f1a17acf71a11..4e8d77f01eeb0913527373ed38a71795cc0b7be1 100644 (file)
--- 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 +393,18 @@ 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) {
+                       WARN_ONCE(1, KERN_INFO "mtrr: your BIOS has set up an incorrect mask, fixing it up.\n");
+                       mask_lo = tmp;
+               }
+       }
 
        /* This works correctly if size is a power of two, i.e. a
           contiguous range. */