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/hugetlb.h>
   6#include <linux/module.h>
   7#include <linux/mm.h>
   8#include <asm/cacheflush.h>
   9#include <asm/facility.h>
  10#include <asm/pgtable.h>
  11#include <asm/page.h>
  12
  13#if PAGE_DEFAULT_KEY
  14static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
  15{
  16        asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
  17                     : [addr] "+a" (addr) : [skey] "d" (skey));
  18        return addr;
  19}
  20
  21void __storage_key_init_range(unsigned long start, unsigned long end)
  22{
  23        unsigned long boundary, size;
  24
  25        while (start < end) {
  26                if (MACHINE_HAS_EDAT1) {
  27                        /* set storage keys for a 1MB frame */
  28                        size = 1UL << 20;
  29                        boundary = (start + size) & ~(size - 1);
  30                        if (boundary <= end) {
  31                                do {
  32                                        start = sske_frame(start, PAGE_DEFAULT_KEY);
  33                                } while (start < boundary);
  34                                continue;
  35                        }
  36                }
  37                page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
  38                start += PAGE_SIZE;
  39        }
  40}
  41#endif
  42
  43static pte_t *walk_page_table(unsigned long addr)
  44{
  45        pgd_t *pgdp;
  46        pud_t *pudp;
  47        pmd_t *pmdp;
  48        pte_t *ptep;
  49
  50        pgdp = pgd_offset_k(addr);
  51        if (pgd_none(*pgdp))
  52                return NULL;
  53        pudp = pud_offset(pgdp, addr);
  54        if (pud_none(*pudp) || pud_large(*pudp))
  55                return NULL;
  56        pmdp = pmd_offset(pudp, addr);
  57        if (pmd_none(*pmdp) || pmd_large(*pmdp))
  58                return NULL;
  59        ptep = pte_offset_kernel(pmdp, addr);
  60        if (pte_none(*ptep))
  61                return NULL;
  62        return ptep;
  63}
  64
  65static void change_page_attr(unsigned long addr, int numpages,
  66                             pte_t (*set) (pte_t))
  67{
  68        pte_t *ptep;
  69        int i;
  70
  71        for (i = 0; i < numpages; i++) {
  72                ptep = walk_page_table(addr);
  73                if (WARN_ON_ONCE(!ptep))
  74                        break;
  75                *ptep = set(*ptep);
  76                addr += PAGE_SIZE;
  77        }
  78        __tlb_flush_kernel();
  79}
  80
  81int set_memory_ro(unsigned long addr, int numpages)
  82{
  83        change_page_attr(addr, numpages, pte_wrprotect);
  84        return 0;
  85}
  86
  87int set_memory_rw(unsigned long addr, int numpages)
  88{
  89        change_page_attr(addr, numpages, pte_mkwrite);
  90        return 0;
  91}
  92
  93/* not possible */
  94int set_memory_nx(unsigned long addr, int numpages)
  95{
  96        return 0;
  97}
  98
  99int set_memory_x(unsigned long addr, int numpages)
 100{
 101        return 0;
 102}
 103
 104#ifdef CONFIG_DEBUG_PAGEALLOC
 105
 106static void ipte_range(pte_t *pte, unsigned long address, int nr)
 107{
 108        int i;
 109
 110        if (test_facility(13)) {
 111                __ptep_ipte_range(address, nr - 1, pte);
 112                return;
 113        }
 114        for (i = 0; i < nr; i++) {
 115                __ptep_ipte(address, pte);
 116                address += PAGE_SIZE;
 117                pte++;
 118        }
 119}
 120
 121void __kernel_map_pages(struct page *page, int numpages, int enable)
 122{
 123        unsigned long address;
 124        int nr, i, j;
 125        pgd_t *pgd;
 126        pud_t *pud;
 127        pmd_t *pmd;
 128        pte_t *pte;
 129
 130        for (i = 0; i < numpages;) {
 131                address = page_to_phys(page + i);
 132                pgd = pgd_offset_k(address);
 133                pud = pud_offset(pgd, address);
 134                pmd = pmd_offset(pud, address);
 135                pte = pte_offset_kernel(pmd, address);
 136                nr = (unsigned long)pte >> ilog2(sizeof(long));
 137                nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
 138                nr = min(numpages - i, nr);
 139                if (enable) {
 140                        for (j = 0; j < nr; j++) {
 141                                pte_val(*pte) = __pa(address);
 142                                address += PAGE_SIZE;
 143                                pte++;
 144                        }
 145                } else {
 146                        ipte_range(pte, address, nr);
 147                }
 148                i += nr;
 149        }
 150}
 151
 152#ifdef CONFIG_HIBERNATION
 153bool kernel_page_present(struct page *page)
 154{
 155        unsigned long addr;
 156        int cc;
 157
 158        addr = page_to_phys(page);
 159        asm volatile(
 160                "       lra     %1,0(%1)\n"
 161                "       ipm     %0\n"
 162                "       srl     %0,28"
 163                : "=d" (cc), "+a" (addr) : : "cc");
 164        return cc == 0;
 165}
 166#endif /* CONFIG_HIBERNATION */
 167
 168#endif /* CONFIG_DEBUG_PAGEALLOC */
 169