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authorIngo Molnar <mingo@elte.hu>2008-08-22 06:06:51 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-22 06:06:51 +0200
commit8b53b57576292b92b27769f9e213df19b6e57786 (patch)
treecd851ce4fa71b2653f120d7f11a9c6cbcf311b19 /arch/x86/kernel/cpu/mtrr/generic.c
parentab7e79243746e2a9c5f00243e60108189c44c9eb (diff)
parent38cc1c3df77c1bb739a4766788eb9fa49f16ffdf (diff)
downloadlwn-8b53b57576292b92b27769f9e213df19b6e57786.tar.gz
lwn-8b53b57576292b92b27769f9e213df19b6e57786.zip
Merge branch 'x86/urgent' into x86/pat
Conflicts: arch/x86/mm/pageattr.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/generic.c')
-rw-r--r--arch/x86/kernel/cpu/mtrr/generic.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 509bd3d9eacd..43102e03e2d1 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 +393,18 @@ 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_ON("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. */