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| author | Yinghai Lu <yinghai@kernel.org> | 2009-03-16 16:33:59 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-17 10:47:47 +0100 |
| commit | f0348c438c9ea156194d31fadde4a9e75522196f (patch) | |
| tree | e06511311bbe5ca161526f9ab494765efe628413 /arch/x86/kernel/cpu/mtrr/cleanup.c | |
| parent | d4c90e37a21154c1910b2646e9544bdd32d5bc3a (diff) | |
| download | linux-stable-f0348c438c9ea156194d31fadde4a9e75522196f.tar.gz linux-stable-f0348c438c9ea156194d31fadde4a9e75522196f.tar.bz2 linux-stable-f0348c438c9ea156194d31fadde4a9e75522196f.zip | |
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>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/cleanup.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/cleanup.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c index 58b58bbf7eb3..f4f89fbc228f 100644 --- a/arch/x86/kernel/cpu/mtrr/cleanup.c +++ b/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -189,6 +189,17 @@ x86_get_mtrr_mem_range(struct res_range *range, int nr_range, if (!size) continue; base = range_state[i].base_pfn; + if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed && + (mtrr_state.enabled & 1)) { + /* Var MTRR contains UC entry below 1M? Skip it: */ + printk(KERN_WARNING "WARNING: BIOS bug: VAR MTRR %d " + "contains strange UC entry under 1M, check " + "with your system vendor!\n", i); + if (base + size <= (1<<(20-PAGE_SHIFT))) + continue; + size -= (1<<(20-PAGE_SHIFT)) - base; + base = 1<<(20-PAGE_SHIFT); + } subtract_range(range, base, base + size - 1); } if (extra_remove_size) |