x86: simplify __change_page_attr()

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

1 files changed, 18 insertions, 29 deletions

diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c
index cbded8300e36..5eff244c16db 100644
--- 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);