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powerpc/64s/radix: Fix memory hotplug section page table creation 

create_physical_mapping expects physical addresses, but creating and
splitting these mappings after boot is supplying virtual (effective)
addresses. This can be irritated by booting with mem= to limit memory
then probing an unused physical memory range:

  echo <addr> > /sys/devices/system/memory/probe

This mostly works by accident, firstly because __va(__va(x)) == __va(x)
so the virtual address does not get corrupted. Secondly because pfn_pte
masks out the upper bits of the pfn beyond the physical address limit,
so a pfn constructed with a 0xc000000000000000 virtual linear address
will be masked back to the correct physical address in the pte.

Fixes: 6cc27341b2 ("powerpc/mm: add radix__create_section_mapping()")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190724084638.24982-1-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2019-07-24 18:46:34 +10:00 committed by Michael Ellerman
parent e354d7dc81
commit 8f51e39294
1 changed files with 1 additions and 1 deletions
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2
arch/powerpc/mm/book3s64/radix_pgtable.c
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@ -902,7 +902,7 @@ int __meminit radix__create_section_mapping(unsigned long start, unsigned long e
return -1; return -1;
} }
return create_physical_mapping(start, end, nid); return create_physical_mapping(__pa(start), __pa(end), nid);
} }
int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end) int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end)