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/mm.h>
   7 #include <asm/cacheflush.h>
   8 #include <asm/facility.h>
   9 #include <asm/pgtable.h>
  10 #include <asm/pgalloc.h>
  11 #include <asm/page.h>
  12 #include <asm/set_memory.h>
  13
  14 static 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
  21 void __storage_key_init_range(unsigned long start, unsigned long end)
  22 {
  23         unsigned long boundary, size;
  24
  25         if (!PAGE_DEFAULT_KEY)
  26                 return;
  27         while (start < end) {
  28                 if (MACHINE_HAS_EDAT1) {
  29                         /* set storage keys for a 1MB frame */
  30                         size = 1UL << 20;
  31                         boundary = (start + size) & ~(size - 1);
  32                         if (boundary <= end) {
  33                                 do {
  34                                         start = sske_frame(start, PAGE_DEFAULT_KEY);
  35                                 } while (start < boundary);
  36                                 continue;
  37                         }
  38                 }
  39                 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
  40                 start += PAGE_SIZE;
  41         }
  42 }
  43
  44 #ifdef CONFIG_PROC_FS
  45 atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
  46
  47 void arch_report_meminfo(struct seq_file *m)
  48 {
  49         seq_printf(m, "DirectMap4k:    %8lu kB\n",
  50                    atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2);
  51         seq_printf(m, "DirectMap1M:    %8lu kB\n",
  52                    atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10);
  53         seq_printf(m, "DirectMap2G:    %8lu kB\n",
  54                    atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21);
  55 }
  56 #endif /* CONFIG_PROC_FS */
  57
  58 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
  59                     unsigned long dtt)
  60 {
  61         unsigned long table, mask;
  62
  63         mask = 0;
  64         if (MACHINE_HAS_EDAT2) {
  65                 switch (dtt) {
  66                 case CRDTE_DTT_REGION3:
  67                         mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1);
  68                         break;
  69                 case CRDTE_DTT_SEGMENT:
  70                         mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
  71                         break;
  72                 case CRDTE_DTT_PAGE:
  73                         mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
  74                         break;
  75                 }
  76                 table = (unsigned long)old & mask;
  77                 crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce);
  78         } else if (MACHINE_HAS_IDTE) {
  79                 cspg(old, *old, new);
  80         } else {
  81                 csp((unsigned int *)old + 1, *old, new);
  82         }
  83 }
  84
  85 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
  86                           unsigned long flags)
  87 {
  88         pte_t *ptep, new;
  89
  90         ptep = pte_offset(pmdp, addr);
  91         do {
  92                 new = *ptep;
  93                 if (pte_none(new))
  94                         return -EINVAL;
  95                 if (flags & SET_MEMORY_RO)
  96                         new = pte_wrprotect(new);
  97                 else if (flags & SET_MEMORY_RW)
  98                         new = pte_mkwrite(pte_mkdirty(new));
  99                 if (flags & SET_MEMORY_NX)
 100                         pte_val(new) |= _PAGE_NOEXEC;
 101                 else if (flags & SET_MEMORY_X)
 102                         pte_val(new) &= ~_PAGE_NOEXEC;
 103                 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);
 104                 ptep++;
 105                 addr += PAGE_SIZE;
 106                 cond_resched();
 107         } while (addr < end);
 108         return 0;
 109 }
 110
 111 static int split_pmd_page(pmd_t *pmdp, unsigned long addr)
 112 {
 113         unsigned long pte_addr, prot;
 114         pte_t *pt_dir, *ptep;
 115         pmd_t new;
 116         int i, ro, nx;
 117
 118         pt_dir = vmem_pte_alloc();
 119         if (!pt_dir)
 120                 return -ENOMEM;
 121         pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT;
 122         ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT);
 123         nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC);
 124         prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
 125         if (!nx)
 126                 prot &= ~_PAGE_NOEXEC;
 127         ptep = pt_dir;
 128         for (i = 0; i < PTRS_PER_PTE; i++) {
 129                 pte_val(*ptep) = pte_addr | prot;
 130                 pte_addr += PAGE_SIZE;
 131                 ptep++;
 132         }
 133         pmd_val(new) = __pa(pt_dir) | _SEGMENT_ENTRY;
 134         pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
 135         update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE);
 136         update_page_count(PG_DIRECT_MAP_1M, -1);
 137         return 0;
 138 }
 139
 140 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr,
 141                             unsigned long flags)
 142 {
 143         pmd_t new = *pmdp;
 144
 145         if (flags & SET_MEMORY_RO)
 146                 new = pmd_wrprotect(new);
 147         else if (flags & SET_MEMORY_RW)
 148                 new = pmd_mkwrite(pmd_mkdirty(new));
 149         if (flags & SET_MEMORY_NX)
 150                 pmd_val(new) |= _SEGMENT_ENTRY_NOEXEC;
 151         else if (flags & SET_MEMORY_X)
 152                 pmd_val(new) &= ~_SEGMENT_ENTRY_NOEXEC;
 153         pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
 154 }
 155
 156 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end,
 157                           unsigned long flags)
 158 {
 159         unsigned long next;
 160         pmd_t *pmdp;
 161         int rc = 0;
 162
 163         pmdp = pmd_offset(pudp, addr);
 164         do {
 165                 if (pmd_none(*pmdp))
 166                         return -EINVAL;
 167                 next = pmd_addr_end(addr, end);
 168                 if (pmd_large(*pmdp)) {
 169                         if (addr & ~PMD_MASK || addr + PMD_SIZE > next) {
 170                                 rc = split_pmd_page(pmdp, addr);
 171                                 if (rc)
 172                                         return rc;
 173                                 continue;
 174                         }
 175                         modify_pmd_page(pmdp, addr, flags);
 176                 } else {
 177                         rc = walk_pte_level(pmdp, addr, next, flags);
 178                         if (rc)
 179                                 return rc;
 180                 }
 181                 pmdp++;
 182                 addr = next;
 183                 cond_resched();
 184         } while (addr < end);
 185         return rc;
 186 }
 187
 188 static int split_pud_page(pud_t *pudp, unsigned long addr)
 189 {
 190         unsigned long pmd_addr, prot;
 191         pmd_t *pm_dir, *pmdp;
 192         pud_t new;
 193         int i, ro, nx;
 194
 195         pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
 196         if (!pm_dir)
 197                 return -ENOMEM;
 198         pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
 199         ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
 200         nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
 201         prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
 202         if (!nx)
 203                 prot &= ~_SEGMENT_ENTRY_NOEXEC;
 204         pmdp = pm_dir;
 205         for (i = 0; i < PTRS_PER_PMD; i++) {
 206                 pmd_val(*pmdp) = pmd_addr | prot;
 207                 pmd_addr += PMD_SIZE;
 208                 pmdp++;
 209         }
 210         pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY;
 211         pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
 212         update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
 213         update_page_count(PG_DIRECT_MAP_2G, -1);
 214         return 0;
 215 }
 216
 217 static void modify_pud_page(pud_t *pudp, unsigned long addr,
 218                             unsigned long flags)
 219 {
 220         pud_t new = *pudp;
 221
 222         if (flags & SET_MEMORY_RO)
 223                 new = pud_wrprotect(new);
 224         else if (flags & SET_MEMORY_RW)
 225                 new = pud_mkwrite(pud_mkdirty(new));
 226         if (flags & SET_MEMORY_NX)
 227                 pud_val(new) |= _REGION_ENTRY_NOEXEC;
 228         else if (flags & SET_MEMORY_X)
 229                 pud_val(new) &= ~_REGION_ENTRY_NOEXEC;
 230         pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
 231 }
 232
 233 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end,
 234                           unsigned long flags)
 235 {
 236         unsigned long next;
 237         pud_t *pudp;
 238         int rc = 0;
 239
 240         pudp = pud_offset(p4d, addr);
 241         do {
 242                 if (pud_none(*pudp))
 243                         return -EINVAL;
 244                 next = pud_addr_end(addr, end);
 245                 if (pud_large(*pudp)) {
 246                         if (addr & ~PUD_MASK || addr + PUD_SIZE > next) {
 247                                 rc = split_pud_page(pudp, addr);
 248                                 if (rc)
 249                                         break;
 250                                 continue;
 251                         }
 252                         modify_pud_page(pudp, addr, flags);
 253                 } else {
 254                         rc = walk_pmd_level(pudp, addr, next, flags);
 255                 }
 256                 pudp++;
 257                 addr = next;
 258                 cond_resched();
 259         } while (addr < end && !rc);
 260         return rc;
 261 }
 262
 263 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
 264                           unsigned long flags)
 265 {
 266         unsigned long next;
 267         p4d_t *p4dp;
 268         int rc = 0;
 269
 270         p4dp = p4d_offset(pgd, addr);
 271         do {
 272                 if (p4d_none(*p4dp))
 273                         return -EINVAL;
 274                 next = p4d_addr_end(addr, end);
 275                 rc = walk_pud_level(p4dp, addr, next, flags);
 276                 p4dp++;
 277                 addr = next;
 278                 cond_resched();
 279         } while (addr < end && !rc);
 280         return rc;
 281 }
 282
 283 static DEFINE_MUTEX(cpa_mutex);
 284
 285 static int change_page_attr(unsigned long addr, unsigned long end,
 286                             unsigned long flags)
 287 {
 288         unsigned long next;
 289         int rc = -EINVAL;
 290         pgd_t *pgdp;
 291
 292         if (addr == end)
 293                 return 0;
 294         if (end >= MODULES_END)
 295                 return -EINVAL;
 296         mutex_lock(&cpa_mutex);
 297         pgdp = pgd_offset_k(addr);
 298         do {
 299                 if (pgd_none(*pgdp))
 300                         break;
 301                 next = pgd_addr_end(addr, end);
 302                 rc = walk_p4d_level(pgdp, addr, next, flags);
 303                 if (rc)
 304                         break;
 305                 cond_resched();
 306         } while (pgdp++, addr = next, addr < end && !rc);
 307         mutex_unlock(&cpa_mutex);
 308         return rc;
 309 }
 310
 311 int __set_memory(unsigned long addr, int numpages, unsigned long flags)
 312 {
 313         if (!MACHINE_HAS_NX)
 314                 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
 315         if (!flags)
 316                 return 0;
 317         addr &= PAGE_MASK;
 318         return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags);
 319 }
 320
 321 #ifdef CONFIG_DEBUG_PAGEALLOC
 322
 323 static void ipte_range(pte_t *pte, unsigned long address, int nr)
 324 {
 325         int i;
 326
 327         if (test_facility(13)) {
 328                 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
 329                 return;
 330         }
 331         for (i = 0; i < nr; i++) {
 332                 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
 333                 address += PAGE_SIZE;
 334                 pte++;
 335         }
 336 }
 337
 338 void __kernel_map_pages(struct page *page, int numpages, int enable)
 339 {
 340         unsigned long address;
 341         int nr, i, j;
 342         pgd_t *pgd;
 343         p4d_t *p4d;
 344         pud_t *pud;
 345         pmd_t *pmd;
 346         pte_t *pte;
 347
 348         for (i = 0; i < numpages;) {
 349                 address = page_to_phys(page + i);
 350                 pgd = pgd_offset_k(address);
 351                 p4d = p4d_offset(pgd, address);
 352                 pud = pud_offset(p4d, address);
 353                 pmd = pmd_offset(pud, address);
 354                 pte = pte_offset_kernel(pmd, address);
 355                 nr = (unsigned long)pte >> ilog2(sizeof(long));
 356                 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
 357                 nr = min(numpages - i, nr);
 358                 if (enable) {
 359                         for (j = 0; j < nr; j++) {
 360                                 pte_val(*pte) &= ~_PAGE_INVALID;
 361                                 address += PAGE_SIZE;
 362                                 pte++;
 363                         }
 364                 } else {
 365                         ipte_range(pte, address, nr);
 366                 }
 367                 i += nr;
 368         }
 369 }
 370
 371 #ifdef CONFIG_HIBERNATION
 372 bool kernel_page_present(struct page *page)
 373 {
 374         unsigned long addr;
 375         int cc;
 376
 377         addr = page_to_phys(page);
 378         asm volatile(
 379                 "       lra     %1,0(%1)\n"
 380                 "       ipm     %0\n"
 381                 "       srl     %0,28"
 382                 : "=d" (cc), "+a" (addr) : : "cc");
 383         return cc == 0;
 384 }
 385 #endif /* CONFIG_HIBERNATION */
 386
 387 #endif /* CONFIG_DEBUG_PAGEALLOC */