x86: MTRR workaround for system with stange var MTRRs

Impact: don't trim e820 according to wrong mtrr

Ozan reports that his server emits strange warning.
it turns out the BIOS sets the MTRRs incorrectly.

Ignore those strange ranges, and don't trim e820,
just emit one warning about BIOS

Reported-by: Ozan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BEE1E7.7020706@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
index 6710e93021a7..77f67f7b347a 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -79,6 +79,7 @@ extern struct mtrr_ops * mtrr_if;
 
 extern unsigned int num_var_ranges;
 extern u64 mtrr_tom2;
+extern struct mtrr_state_type mtrr_state;
 
 void mtrr_state_warn(void);
 const char *mtrr_attrib_to_str(int x);