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authorJacob Shin <jacob.shin@amd.com>2011-10-20 16:15:26 -0500
committerH. Peter Anvin <hpa@linux.intel.com>2012-10-17 10:59:39 -0700
commit1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a (patch)
treeab09b4f7fded56cf36943ec56ef6b54baa786b67 /arch
parent961c79761dda351b5fb263a0654b98daac130b7a (diff)
downloadlinux-1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a.tar.bz2
x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
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. ] Cc: stable@kernel.org # > 2.6.32 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>
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 f4b9b80e1b95..198e774498ec 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -919,8 +919,21 @@ 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;
}