x86: implement gbpages support in change_page_attr()

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 15 insertions, 2 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 143fbafc948a..42ca3d8effad 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -281,7 +281,12 @@ static int try_preserve_large_page(pte_t *kpte, unsigned long address,
                 psize = PMD_PAGE_SIZE;
                 pmask = PMD_PAGE_MASK;
                 break;
+#ifdef CONFIG_X86_64
         case PG_LEVEL_1G:
+                psize = PMD_PAGE_SIZE;
+                pmask = PMD_PAGE_MASK;
+                break;
+#endif
         default:
                 res = -EINVAL;
                 goto out_unlock;
@@ -343,7 +348,7 @@ static int split_large_page(pte_t *kpte, unsigned long address)
 {
         pgprot_t ref_prot;
         gfp_t gfp_flags = GFP_KERNEL;
-        unsigned long flags, addr, pfn;
+        unsigned long flags, addr, pfn, pfninc = 1;
         pte_t *pbase, *tmp;
         struct page *base;
         unsigned int i, level;
@@ -372,11 +377,19 @@ static int split_large_page(pte_t *kpte, unsigned long address)
 #endif
         ref_prot = pte_pgprot(pte_clrhuge(*kpte));
 
+#ifdef CONFIG_X86_64
+        if (level == PG_LEVEL_1G) {
+                pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
+                pgprot_val(ref_prot) |= _PAGE_PSE;
+                addr &= PUD_PAGE_MASK;
+        }
+#endif
+
         /*
          * Get the target pfn from the original entry:
          */
         pfn = pte_pfn(*kpte);
-        for (i = 0; i < PTRS_PER_PTE; i++, pfn++)
+        for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
                 set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
 
         /*