commit: 1bbbbe779aabe1f0768c2bf8f8c0a5583679b54a From: Jacob Shin <[email protected]> Date: Thu, 20 Oct 2011 16:15:26 -0500 Subject: 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: [email protected] # > 2.6.32 Signed-off-by: Jacob Shin <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: H. Peter Anvin <[email protected]> --- arch/x86/kernel/setup.c | 17 +++++++++++++++-- 1 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index f4b9b80..198e774 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; } -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
