x86: introduce max_low_pfn_mapped for 64-bit
when more than 4g memory is installed, don't map the big hole below 4g.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index afd4005..0389cb8 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -536,8 +536,14 @@
set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
if (address >= (unsigned long)__va(0) &&
+ address < (unsigned long)__va(max_low_pfn_mapped << PAGE_SHIFT))
+ split_page_count(level);
+
+#ifdef CONFIG_X86_64
+ if (address >= (unsigned long)__va(1UL<<32) &&
address < (unsigned long)__va(max_pfn_mapped << PAGE_SHIFT))
split_page_count(level);
+#endif
/*
* Install the new, split up pagetable. Important details here:
@@ -655,12 +661,21 @@
if (cpa->pfn > max_pfn_mapped)
return 0;
+#ifdef CONFIG_X86_64
+ if (cpa->pfn > max_low_pfn_mapped && cpa->pfn < (1UL<<(32-PAGE_SHIFT)))
+ return 0;
+#endif
/*
* No need to redo, when the primary call touched the direct
* mapping already:
*/
- if (!within(cpa->vaddr, PAGE_OFFSET,
- PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
+ if (!(within(cpa->vaddr, PAGE_OFFSET,
+ PAGE_OFFSET + (max_low_pfn_mapped << PAGE_SHIFT))
+#ifdef CONFIG_X86_64
+ || within(cpa->vaddr, PAGE_OFFSET + (1UL<<32),
+ PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))
+#endif
+ )) {
alias_cpa = *cpa;
alias_cpa.vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);