x86: simplify __change_page_attr()

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

diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c
index cbded8300e362ca23719f9cd0f53f173895ad2cc..5eff244c16dba0b3c4271b94c8ad1a00169c136b 100644 (file)
--- a/arch/x86/mm/pageattr_64.c
+++ b/arch/x86/mm/pageattr_64.c
@@ -67,8 +67,7 @@ split_large_page(unsigned long address, pgprot_t ref_prot)
 }
 
 static int
-__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
-                  pgprot_t ref_prot)
+__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot)
 {
        struct page *kpte_page;
        pte_t *kpte;
@@ -84,32 +83,24 @@ repeat:
        oldprot = pte_pgprot(*kpte);
        BUG_ON(PageLRU(kpte_page));
        BUG_ON(PageCompound(kpte_page));
-       ref_prot = canon_pgprot(ref_prot);
        prot = canon_pgprot(prot);
 
-       if (pgprot_val(prot) != pgprot_val(ref_prot)) {
-               if (level == 4) {
-                       set_pte(kpte, pfn_pte(pfn, prot));
-               } else {
-                       /*
-                        * split_large_page will take the reference for this
-                        * change_page_attr on the split page.
-                        */
-                       struct page *split;
-
-                       ref_prot2 = pte_pgprot(pte_clrhuge(*kpte));
-                       split = split_large_page(address, ref_prot2);
-                       if (!split)
-                               return -ENOMEM;
-                       pgprot_val(ref_prot2) &= ~_PAGE_NX;
-                       set_pte(kpte, mk_pte(split, ref_prot2));
-                       goto repeat;
-               }
+       if (level == 4) {
+               set_pte(kpte, pfn_pte(pfn, prot));
        } else {
-               if (level == 4) {
-                       set_pte(kpte, pfn_pte(pfn, ref_prot));
-               } else
-                       BUG();
+               /*
+                * split_large_page will take the reference for this
+                * change_page_attr on the split page.
+                */
+               struct page *split;
+
+               ref_prot2 = pte_pgprot(pte_clrhuge(*kpte));
+               split = split_large_page(address, ref_prot2);
+               if (!split)
+                       return -ENOMEM;
+               pgprot_val(ref_prot2) &= ~_PAGE_NX;
+               set_pte(kpte, mk_pte(split, ref_prot2));
+               goto repeat;
        }
 
        return 0;
@@ -144,8 +135,7 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
                unsigned long pfn = __pa(address) >> PAGE_SHIFT;
 
                if (!kernel_map || pte_present(pfn_pte(0, prot))) {
-                       err = __change_page_attr(address, pfn, prot,
-                                               PAGE_KERNEL);
+                       err = __change_page_attr(address, pfn, prot);
                        if (err)
                                break;
                }
@@ -158,8 +148,7 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
                        addr2 = __START_KERNEL_map + __pa(address);
                        /* Make sure the kernel mappings stay executable */
                        prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
-                       err = __change_page_attr(addr2, pfn, prot2,
-                                                PAGE_KERNEL_EXEC);
+                       err = __change_page_attr(addr2, pfn, prot2);
                }
        }
        up_write(&init_mm.mmap_sem);