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