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authorJacob Shin <jacob.shin@amd.com>2011-10-20 16:15:26 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-28 10:02:11 -0700
commitbd7bca8d191425ff8ad7e0f3a30abdb652aff77f (patch)
treef3f9bee95c373f3d7b191d74c85a08fb7f4c6006 /arch
parent2f3dc85d233fce3345eb1880ec44349d7b290211 (diff)
x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
commit 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a upstream. On systems with very large memory (1 TB in our case), BIOS may report a reserved region or a hole in the E820 map, even above the 4 GB range. Exclude these from the direct mapping. [ hpa: this should be done not just for > 4 GB but for everything above the legacy region (1 MB), at the very least. That, however, turns out to require significant restructuring. That work is well underway, but is not suitable for rc/stable. ] Signed-off-by: Jacob Shin <jacob.shin@amd.com> Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/setup.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index afaf38447ef5..af19a61443f6 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -937,8 +937,21 @@ void __init setup_arch(char **cmdline_p)
#ifdef CONFIG_X86_64
if (max_pfn > max_low_pfn) {
- max_pfn_mapped = init_memory_mapping(1UL<<32,
- max_pfn<<PAGE_SHIFT);
+ int i;
+ for (i = 0; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+
+ if (ei->addr + ei->size <= 1UL << 32)
+ continue;
+
+ if (ei->type == E820_RESERVED)
+ continue;
+
+ max_pfn_mapped = init_memory_mapping(
+ ei->addr < 1UL << 32 ? 1UL << 32 : ei->addr,
+ ei->addr + ei->size);
+ }
+
/* can we preseve max_low_pfn ?*/
max_low_pfn = max_pfn;
}