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authorYinghai Lu <yhlu.kernel@gmail.com>2008-10-04 14:50:32 -0700
committerH. Peter Anvin <hpa@zytor.com>2008-10-04 20:09:14 -0700
commit99e1aa17ce434010dd820b583628370cc15f10f3 (patch)
treef856dd2dd02d6986f590eb47b2fe3cf814807b57 /arch
parent42fde7a05c5d6dc76e518ae12091ea897b1c132b (diff)
x86: mtrr_cleanup: first 1M may be covered in var mtrrs
The first 1M is don't care when it comes to the variables MTRRs. Cover it as WB as a heuristic approximation; this is generally what we want to minimize the number of registers. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/mtrr/main.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 9086b38fbab..663e530e08e 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -1293,6 +1293,15 @@ static int __init mtrr_cleanup(unsigned address_bits)
}
nr_range = x86_get_mtrr_mem_range(range, 0, extra_remove_base,
extra_remove_size);
+ /*
+ * [0, 1M) should always be coverred by var mtrr with WB
+ * and fixed mtrrs should take effective before var mtrr for it
+ */
+ nr_range = add_range_with_merge(range, nr_range, 0,
+ (1ULL<<(20 - PAGE_SHIFT)) - 1);
+ /* sort the ranges */
+ sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
+
range_sums = sum_ranges(range, nr_range);
printk(KERN_INFO "total RAM coverred: %ldM\n",
range_sums >> (20 - PAGE_SHIFT));