Merge tag 'imx-fixes-rc' of git://git.pengutronix.de/git/imx/linux-2.6 into fixes

[karo-tx-linux.git] / arch / s390 / mm / pageattr.c

diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index b36537a5f43e33e3a1a6cc9907efcf3920e8d583..00be01c4b4f3fc3ee8242ea1e7b6921bfc6afc2a 100644 (file)
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -8,25 +8,38 @@
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
 
+static pte_t *walk_page_table(unsigned long addr)
+{
+       pgd_t *pgdp;
+       pud_t *pudp;
+       pmd_t *pmdp;
+       pte_t *ptep;
+
+       pgdp = pgd_offset_k(addr);
+       if (pgd_none(*pgdp))
+               return NULL;
+       pudp = pud_offset(pgdp, addr);
+       if (pud_none(*pudp))
+               return NULL;
+       pmdp = pmd_offset(pudp, addr);
+       if (pmd_none(*pmdp) || pmd_large(*pmdp))
+               return NULL;
+       ptep = pte_offset_kernel(pmdp, addr);
+       if (pte_none(*ptep))
+               return NULL;
+       return ptep;
+}
+
 static void change_page_attr(unsigned long addr, int numpages,
                             pte_t (*set) (pte_t))
 {
        pte_t *ptep, pte;
-       pmd_t *pmdp;
-       pud_t *pudp;
-       pgd_t *pgdp;
        int i;
 
        for (i = 0; i < numpages; i++) {
-               pgdp = pgd_offset(&init_mm, addr);
-               pudp = pud_offset(pgdp, addr);
-               pmdp = pmd_offset(pudp, addr);
-               if (pmd_huge(*pmdp)) {
-                       WARN_ON_ONCE(1);
-                       continue;
-               }
-               ptep = pte_offset_kernel(pmdp, addr);
-
+               ptep = walk_page_table(addr);
+               if (WARN_ON_ONCE(!ptep))
+                       break;
                pte = *ptep;
                pte = set(pte);
                __ptep_ipte(addr, ptep);
@@ -40,21 +53,18 @@ int set_memory_ro(unsigned long addr, int numpages)
        change_page_attr(addr, numpages, pte_wrprotect);
        return 0;
 }
-EXPORT_SYMBOL_GPL(set_memory_ro);
 
 int set_memory_rw(unsigned long addr, int numpages)
 {
        change_page_attr(addr, numpages, pte_mkwrite);
        return 0;
 }
-EXPORT_SYMBOL_GPL(set_memory_rw);
 
 /* not possible */
 int set_memory_nx(unsigned long addr, int numpages)
 {
        return 0;
 }
-EXPORT_SYMBOL_GPL(set_memory_nx);
 
 int set_memory_x(unsigned long addr, int numpages)
 {