arch/s390/mm/pageattr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright IBM Corp. 2011
   4  * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
   5  */
   6 #include <linux/hugetlb.h>
   7 #include <linux/mm.h>
   8 #include <asm/cacheflush.h>
   9 #include <asm/facility.h>
  10 #include <asm/pgtable.h>
  11 #include <asm/pgalloc.h>
  12 #include <asm/page.h>
  13 #include <asm/set_memory.h>
  14
  15 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
  16 {
  17         asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
  18                      : [addr] "+a" (addr) : [skey] "d" (skey));
  19         return addr;
  20 }
  21
  22 void __storage_key_init_range(unsigned long start, unsigned long end)
  23 {
  24         unsigned long boundary, size;
  25
  26         if (!PAGE_DEFAULT_KEY)
  27                 return;
  28         while (start < end) {
  29                 if (MACHINE_HAS_EDAT1) {
  30                         /* set storage keys for a 1MB frame */
  31                         size = 1UL << 20;
  32                         boundary = (start + size) & ~(size - 1);
  33                         if (boundary <= end) {
  34                                 do {
  35                                         start = sske_frame(start, PAGE_DEFAULT_KEY);
  36                                 } while (start < boundary);
  37                                 continue;
  38                         }
  39                 }
  40                 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
  41                 start += PAGE_SIZE;
  42         }
  43 }
  44
  45 #ifdef CONFIG_PROC_FS
  46 atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
  47
  48 void arch_report_meminfo(struct seq_file *m)
  49 {
  50         seq_printf(m, "DirectMap4k:    %8lu kB\n",
  51                    atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2);
  52         seq_printf(m, "DirectMap1M:    %8lu kB\n",
  53                    atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10);
  54         seq_printf(m, "DirectMap2G:    %8lu kB\n",
  55                    atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21);
  56 }
  57 #endif /* CONFIG_PROC_FS */
  58
  59 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
  60                     unsigned long dtt)
  61 {
  62         unsigned long table, mask;
  63
  64         mask = 0;
  65         if (MACHINE_HAS_EDAT2) {
  66                 switch (dtt) {
  67                 case CRDTE_DTT_REGION3:
  68                         mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1);
  69                         break;
  70                 case CRDTE_DTT_SEGMENT:
  71                         mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
  72                         break;
  73                 case CRDTE_DTT_PAGE:
  74                         mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
  75                         break;
  76                 }
  77                 table = (unsigned long)old & mask;
  78                 crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce);
  79         } else if (MACHINE_HAS_IDTE) {
  80                 cspg(old, *old, new);
  81         } else {
  82                 csp((unsigned int *)old + 1, *old, new);
  83         }
  84 }
  85
  86 static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
  87                           unsigned long flags)
  88 {
  89         pte_t *ptep, new;
  90
  91         ptep = pte_offset(pmdp, addr);
  92         do {
  93                 new = *ptep;
  94                 if (pte_none(new))
  95                         return -EINVAL;
  96                 if (flags & SET_MEMORY_RO)
  97                         new = pte_wrprotect(new);
  98                 else if (flags & SET_MEMORY_RW)
  99                         new = pte_mkwrite(pte_mkdirty(new));
 100                 if (flags & SET_MEMORY_NX)
 101                         pte_val(new) |= _PAGE_NOEXEC;
 102                 else if (flags & SET_MEMORY_X)
 103                         pte_val(new) &= ~_PAGE_NOEXEC;
 104                 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE);
 105                 ptep++;
 106                 addr += PAGE_SIZE;
 107                 cond_resched();
 108         } while (addr < end);
 109         return 0;
 110 }
 111
 112 static int split_pmd_page(pmd_t *pmdp, unsigned long addr)
 113 {
 114         unsigned long pte_addr, prot;
 115         pte_t *pt_dir, *ptep;
 116         pmd_t new;
 117         int i, ro, nx;
 118
 119         pt_dir = vmem_pte_alloc();
 120         if (!pt_dir)
 121                 return -ENOMEM;
 122         pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT;
 123         ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT);
 124         nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC);
 125         prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
 126         if (!nx)
 127                 prot &= ~_PAGE_NOEXEC;
 128         ptep = pt_dir;
 129         for (i = 0; i < PTRS_PER_PTE; i++) {
 130                 pte_val(*ptep) = pte_addr | prot;
 131                 pte_addr += PAGE_SIZE;
 132                 ptep++;
 133         }
 134         pmd_val(new) = __pa(pt_dir) | _SEGMENT_ENTRY;
 135         pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
 136         update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE);
 137         update_page_count(PG_DIRECT_MAP_1M, -1);
 138         return 0;
 139 }
 140
 141 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr,
 142                             unsigned long flags)
 143 {
 144         pmd_t new = *pmdp;
 145
 146         if (flags & SET_MEMORY_RO)
 147                 new = pmd_wrprotect(new);
 148         else if (flags & SET_MEMORY_RW)
 149                 new = pmd_mkwrite(pmd_mkdirty(new));
 150         if (flags & SET_MEMORY_NX)
 151                 pmd_val(new) |= _SEGMENT_ENTRY_NOEXEC;
 152         else if (flags & SET_MEMORY_X)
 153                 pmd_val(new) &= ~_SEGMENT_ENTRY_NOEXEC;
 154         pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT);
 155 }
 156
 157 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end,
 158                           unsigned long flags)
 159 {
 160         unsigned long next;
 161         pmd_t *pmdp;
 162         int rc = 0;
 163
 164         pmdp = pmd_offset(pudp, addr);
 165         do {
 166                 if (pmd_none(*pmdp))
 167                         return -EINVAL;
 168                 next = pmd_addr_end(addr, end);
 169                 if (pmd_large(*pmdp)) {
 170                         if (addr & ~PMD_MASK || addr + PMD_SIZE > next) {
 171                                 rc = split_pmd_page(pmdp, addr);
 172                                 if (rc)
 173                                         return rc;
 174                                 continue;
 175                         }
 176                         modify_pmd_page(pmdp, addr, flags);
 177                 } else {
 178                         rc = walk_pte_level(pmdp, addr, next, flags);
 179                         if (rc)
 180                                 return rc;
 181                 }
 182                 pmdp++;
 183                 addr = next;
 184                 cond_resched();
 185         } while (addr < end);
 186         return rc;
 187 }
 188
 189 static int split_pud_page(pud_t *pudp, unsigned long addr)
 190 {
 191         unsigned long pmd_addr, prot;
 192         pmd_t *pm_dir, *pmdp;
 193         pud_t new;
 194         int i, ro, nx;
 195
 196         pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
 197         if (!pm_dir)
 198                 return -ENOMEM;
 199         pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT;
 200         ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT);
 201         nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC);
 202         prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
 203         if (!nx)
 204                 prot &= ~_SEGMENT_ENTRY_NOEXEC;
 205         pmdp = pm_dir;
 206         for (i = 0; i < PTRS_PER_PMD; i++) {
 207                 pmd_val(*pmdp) = pmd_addr | prot;
 208                 pmd_addr += PMD_SIZE;
 209                 pmdp++;
 210         }
 211         pud_val(new) = __pa(pm_dir) | _REGION3_ENTRY;
 212         pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
 213         update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD);
 214         update_page_count(PG_DIRECT_MAP_2G, -1);
 215         return 0;
 216 }
 217
 218 static void modify_pud_page(pud_t *pudp, unsigned long addr,
 219                             unsigned long flags)
 220 {
 221         pud_t new = *pudp;
 222
 223         if (flags & SET_MEMORY_RO)
 224                 new = pud_wrprotect(new);
 225         else if (flags & SET_MEMORY_RW)
 226                 new = pud_mkwrite(pud_mkdirty(new));
 227         if (flags & SET_MEMORY_NX)
 228                 pud_val(new) |= _REGION_ENTRY_NOEXEC;
 229         else if (flags & SET_MEMORY_X)
 230                 pud_val(new) &= ~_REGION_ENTRY_NOEXEC;
 231         pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3);
 232 }
 233
 234 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end,
 235                           unsigned long flags)
 236 {
 237         unsigned long next;
 238         pud_t *pudp;
 239         int rc = 0;
 240
 241         pudp = pud_offset(p4d, addr);
 242         do {
 243                 if (pud_none(*pudp))
 244                         return -EINVAL;
 245                 next = pud_addr_end(addr, end);
 246                 if (pud_large(*pudp)) {
 247                         if (addr & ~PUD_MASK || addr + PUD_SIZE > next) {
 248                                 rc = split_pud_page(pudp, addr);
 249                                 if (rc)
 250                                         break;
 251                                 continue;
 252                         }
 253                         modify_pud_page(pudp, addr, flags);
 254                 } else {
 255                         rc = walk_pmd_level(pudp, addr, next, flags);
 256                 }
 257                 pudp++;
 258                 addr = next;
 259                 cond_resched();
 260         } while (addr < end && !rc);
 261         return rc;
 262 }
 263
 264 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end,
 265                           unsigned long flags)
 266 {
 267         unsigned long next;
 268         p4d_t *p4dp;
 269         int rc = 0;
 270
 271         p4dp = p4d_offset(pgd, addr);
 272         do {
 273                 if (p4d_none(*p4dp))
 274                         return -EINVAL;
 275                 next = p4d_addr_end(addr, end);
 276                 rc = walk_pud_level(p4dp, addr, next, flags);
 277                 p4dp++;
 278                 addr = next;
 279                 cond_resched();
 280         } while (addr < end && !rc);
 281         return rc;
 282 }
 283
 284 static DEFINE_MUTEX(cpa_mutex);
 285
 286 static int change_page_attr(unsigned long addr, unsigned long end,
 287                             unsigned long flags)
 288 {
 289         unsigned long next;
 290         int rc = -EINVAL;
 291         pgd_t *pgdp;
 292
 293         if (addr == end)
 294                 return 0;
 295         if (end >= MODULES_END)
 296                 return -EINVAL;
 297         mutex_lock(&cpa_mutex);
 298         pgdp = pgd_offset_k(addr);
 299         do {
 300                 if (pgd_none(*pgdp))
 301                         break;
 302                 next = pgd_addr_end(addr, end);
 303                 rc = walk_p4d_level(pgdp, addr, next, flags);
 304                 if (rc)
 305                         break;
 306                 cond_resched();
 307         } while (pgdp++, addr = next, addr < end && !rc);
 308         mutex_unlock(&cpa_mutex);
 309         return rc;
 310 }
 311
 312 int __set_memory(unsigned long addr, int numpages, unsigned long flags)
 313 {
 314         if (!MACHINE_HAS_NX)
 315                 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X);
 316         if (!flags)
 317                 return 0;
 318         addr &= PAGE_MASK;
 319         return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags);
 320 }
 321
 322 #ifdef CONFIG_DEBUG_PAGEALLOC
 323
 324 static void ipte_range(pte_t *pte, unsigned long address, int nr)
 325 {
 326         int i;
 327
 328         if (test_facility(13)) {
 329                 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL);
 330                 return;
 331         }
 332         for (i = 0; i < nr; i++) {
 333                 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL);
 334                 address += PAGE_SIZE;
 335                 pte++;
 336         }
 337 }
 338
 339 void __kernel_map_pages(struct page *page, int numpages, int enable)
 340 {
 341         unsigned long address;
 342         int nr, i, j;
 343         pgd_t *pgd;
 344         p4d_t *p4d;
 345         pud_t *pud;
 346         pmd_t *pmd;
 347         pte_t *pte;
 348
 349         for (i = 0; i < numpages;) {
 350                 address = page_to_phys(page + i);
 351                 pgd = pgd_offset_k(address);
 352                 p4d = p4d_offset(pgd, address);
 353                 pud = pud_offset(p4d, address);
 354                 pmd = pmd_offset(pud, address);
 355                 pte = pte_offset_kernel(pmd, address);
 356                 nr = (unsigned long)pte >> ilog2(sizeof(long));
 357                 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
 358                 nr = min(numpages - i, nr);
 359                 if (enable) {
 360                         for (j = 0; j < nr; j++) {
 361                                 pte_val(*pte) &= ~_PAGE_INVALID;
 362                                 address += PAGE_SIZE;
 363                                 pte++;
 364                         }
 365                 } else {
 366                         ipte_range(pte, address, nr);
 367                 }
 368                 i += nr;
 369         }
 370 }
 371
 372 #ifdef CONFIG_HIBERNATION
 373 bool kernel_page_present(struct page *page)
 374 {
 375         unsigned long addr;
 376         int cc;
 377
 378         addr = page_to_phys(page);
 379         asm volatile(
 380                 "       lra     %1,0(%1)\n"
 381                 "       ipm     %0\n"
 382                 "       srl     %0,28"
 383                 : "=d" (cc), "+a" (addr) : : "cc");
 384         return cc == 0;
 385 }
 386 #endif /* CONFIG_HIBERNATION */
 387
 388 #endif /* CONFIG_DEBUG_PAGEALLOC */