Note sure what the point of that change was
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jan 15 16:53:24 2008 +0100
patches/x86-pat-usable_only_map.patch
x86_64: Map only usable memory in identity map. Reserved memory maps to a
zero page.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
---
arch/x86/mm/pageattr_64.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
Index: linux/arch/x86/mm/pageattr_64.c
===================================================================
--- linux.orig/arch/x86/mm/pageattr_64.c
+++ linux/arch/x86/mm/pageattr_64.c
@@ -53,11 +53,9 @@ split_large_page(unsigned long address,
/*
* page_private is used to track the number of entries in
* the page table page have non standard attributes.
- * Count of 1 indicates page split by split_large_page(),
- * additional count indicates the number of pages with non-std attr.
*/
SetPagePrivate(base);
- page_private(base) = 1;
+ page_private(base) = 0;
address = __pa(address);
addr = address & LARGE_PAGE_MASK;
@@ -178,8 +176,11 @@ __change_page_attr(unsigned long address
BUG();
}
+ /* on x86-64 the direct mapping set at boot is not using 4k pages */
+ BUG_ON(PageReserved(kpte_page));
+
save_page(kpte_page);
- if (page_private(kpte_page) == 1)
+ if (page_private(kpte_page) == 0)
revert_page(address, ref_prot);
return 0;
}
--
