x86: return the page table level in lookup_address()

based on this patch from Andi Kleen:

|  Subject: CPA: Return the page table level in lookup_address()
|  From: Andi Kleen <ak@suse.de>
|
|  Needed for the next change.
|
|  And change all the callers.

and ported it to x86.git.

Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c
index be4656403d77..523fd5b37df9 100644
--- a/arch/x86/mm/pageattr_32.c
+++ b/arch/x86/mm/pageattr_32.c
@@ -18,7 +18,7 @@
 static DEFINE_SPINLOCK(cpa_lock);
 static struct list_head df_list = LIST_HEAD_INIT(df_list);
 
-pte_t *lookup_address(unsigned long address)
+pte_t *lookup_address(unsigned long address, int *level)
 {
         pgd_t *pgd = pgd_offset_k(address);
         pud_t *pud;
@@ -32,8 +32,10 @@ pte_t *lookup_address(unsigned long address)
         pmd = pmd_offset(pud, address);
         if (pmd_none(*pmd))
                 return NULL;
+        *level = 2;
         if (pmd_large(*pmd))
                 return (pte_t *)pmd;
+        *level = 3;
 
         return pte_offset_kernel(pmd, address);
 }
@@ -156,11 +158,12 @@ static int __change_page_attr(struct page *page, pgprot_t prot)
         struct page *kpte_page;
         unsigned long address;
         pte_t *kpte;
+        int level;
 
         BUG_ON(PageHighMem(page));
         address = (unsigned long)page_address(page);
 
-        kpte = lookup_address(address);
+        kpte = lookup_address(address, &level);
         if (!kpte)
                 return -EINVAL;