Merge commit 'v2.6.29-rc8' into cpus4096

[safe/jmp/linux-2.6] / arch / x86 / mm / pageattr.c

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 7233bd7..9c42949 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -482,6 +482,13 @@ static int split_large_page(pte_t *kpte, unsigned long address)
        pbase = (pte_t *)page_address(base);
        paravirt_alloc_pte(&init_mm, page_to_pfn(base));
        ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+       /*
+        * If we ever want to utilize the PAT bit, we need to
+        * update this function to make sure it's converted from
+        * bit 12 to bit 7 when we cross from the 2MB level to
+        * the 4K level:
+        */
+       WARN_ON_ONCE(pgprot_val(ref_prot) & _PAGE_PAT_LARGE);
 
 #ifdef CONFIG_X86_64
        if (level == PG_LEVEL_1G) {