LXR linux/arch/s390/mm/pageattr.c

   1/*
   2 * Copyright IBM Corp. 2011
   3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
   4 */
   5#include <linux/module.h>
   6#include <linux/mm.h>
   7#include <linux/hugetlb.h>
   8#include <asm/cacheflush.h>
   9#include <asm/pgtable.h>
  10
  11static void change_page_attr(unsigned long addr, int numpages,
  12                             pte_t (*set) (pte_t))
  13{
  14        pte_t *ptep, pte;
  15        pmd_t *pmdp;
  16        pud_t *pudp;
  17        pgd_t *pgdp;
  18        int i;
  19
  20        for (i = 0; i < numpages; i++) {
  21                pgdp = pgd_offset(&init_mm, addr);
  22                pudp = pud_offset(pgdp, addr);
  23                pmdp = pmd_offset(pudp, addr);
  24                if (pmd_huge(*pmdp)) {
  25                        WARN_ON_ONCE(1);
  26                        continue;
  27                }
  28                ptep = pte_offset_kernel(pmdp, addr);
  29
  30                pte = *ptep;
  31                pte = set(pte);
  32                __ptep_ipte(addr, ptep);
  33                *ptep = pte;
  34                addr += PAGE_SIZE;
  35        }
  36}
  37
  38int set_memory_ro(unsigned long addr, int numpages)
  39{
  40        change_page_attr(addr, numpages, pte_wrprotect);
  41        return 0;
  42}
  43EXPORT_SYMBOL_GPL(set_memory_ro);
  44
  45int set_memory_rw(unsigned long addr, int numpages)
  46{
  47        change_page_attr(addr, numpages, pte_mkwrite);
  48        return 0;
  49}
  50EXPORT_SYMBOL_GPL(set_memory_rw);
  51
  52/* not possible */
  53int set_memory_nx(unsigned long addr, int numpages)
  54{
  55        return 0;
  56}
  57EXPORT_SYMBOL_GPL(set_memory_nx);
  58
  59int set_memory_x(unsigned long addr, int numpages)
  60{
  61        return 0;
  62}
  63