x86: add gbpages support to lookup_address

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

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 74446ea23ffbe5e78715f87197c0a35515be0bfb..143fbafc948ae25c9c8added4a1a7534c0521d9f 100644 (file)
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -119,7 +119,7 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
                /*
                 * Only flush present addresses:
                 */
-               if (pte && pte_present(*pte))
+               if (pte && (pte_val(*pte) & _PAGE_PRESENT))
                        clflush_cache_range((void *) addr, PAGE_SIZE);
        }
 }
@@ -209,6 +209,11 @@ pte_t *lookup_address(unsigned long address, int *level)
        pud = pud_offset(pgd, address);
        if (pud_none(*pud))
                return NULL;
+
+       *level = PG_LEVEL_1G;
+       if (pud_large(*pud) || !pud_present(*pud))
+               return (pte_t *)pud;
+
        pmd = pmd_offset(pud, address);
        if (pmd_none(*pmd))
                return NULL;
@@ -336,7 +341,7 @@ out_unlock:
 
 static int split_large_page(pte_t *kpte, unsigned long address)
 {
-       pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+       pgprot_t ref_prot;
        gfp_t gfp_flags = GFP_KERNEL;
        unsigned long flags, addr, pfn;
        pte_t *pbase, *tmp;
@@ -344,7 +349,6 @@ static int split_large_page(pte_t *kpte, unsigned long address)
        unsigned int i, level;
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
-       gfp_flags = __GFP_HIGH | __GFP_NOFAIL | __GFP_NOWARN;
        gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
 #endif
        base = alloc_pages(gfp_flags, 0);
@@ -357,10 +361,8 @@ static int split_large_page(pte_t *kpte, unsigned long address)
         * up for us already:
         */
        tmp = lookup_address(address, &level);
-       if (tmp != kpte) {
-               WARN_ON_ONCE(1);
+       if (tmp != kpte)
                goto out_unlock;
-       }
 
        address = __pa(address);
        addr = address & PMD_PAGE_MASK;
@@ -368,6 +370,7 @@ static int split_large_page(pte_t *kpte, unsigned long address)
 #ifdef CONFIG_X86_32
        paravirt_alloc_pt(&init_mm, page_to_pfn(base));
 #endif
+       ref_prot = pte_pgprot(pte_clrhuge(*kpte));
 
        /*
         * Get the target pfn from the original entry:
@@ -377,13 +380,17 @@ static int split_large_page(pte_t *kpte, unsigned long address)
                set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
 
        /*
-        * Install the new, split up pagetable. Important detail here:
+        * Install the new, split up pagetable. Important details here:
         *
         * On Intel the NX bit of all levels must be cleared to make a
         * page executable. See section 4.13.2 of Intel 64 and IA-32
         * Architectures Software Developer's Manual).
+        *
+        * Mark the entry present. The current mapping might be
+        * set to not present, which we preserved above.
         */
        ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
+       pgprot_val(ref_prot) |= _PAGE_PRESENT;
        __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
        base = NULL;