x86: set PAE PHYSICAL_MASK_SHIFT to 44 bits.
When a 64-bit x86 processor runs in 32-bit PAE mode, a pte can potentially have the same number of physical address bits as the 64-bit host ("Enhanced Legacy PAE Paging"). This means, in theory, we could have up to 52 bits of physical address in a pte. The 32-bit kernel uses a 32-bit unsigned long to represent a pfn. This means that it can only represent physical addresses up to 32+12=44 bits wide. Rather than widening pfns everywhere, just set 2^44 as the Linux x86_32-PAE architectural limit for physical address size. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
parent
668231141f
commit
ce8e37cdbd
|
@ -14,7 +14,8 @@
|
|||
#define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
|
||||
|
||||
#ifdef CONFIG_X86_PAE
|
||||
#define __PHYSICAL_MASK_SHIFT 36
|
||||
/* 44=32+12, the limit we can fit into an unsigned long pfn */
|
||||
#define __PHYSICAL_MASK_SHIFT 44
|
||||
#define __VIRTUAL_MASK_SHIFT 32
|
||||
#define PAGETABLE_LEVELS 3
|
||||
|
||||
|
|
Loading…
Reference in a new issue