From efd5fa0c1a1d1b46846ea6e8d1a783d0d8a6a721 Mon Sep 17 00:00:00 2001 From: Jacob Shin Date: Thu, 20 Oct 2011 16:15:26 -0500 Subject: [PATCH] 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 Link: http://lkml.kernel.org/r/1319145326-13902-1-git-send-email-jacob.shin@amd.com Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/setup.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 1a2901562059..fbbd1eb6c68e 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -927,8 +927,21 @@ 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<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; } -- 2.39.5