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/cpufeature.h> 7 #include <linux/hugetlb.h> 8 #include <linux/proc_fs.h> 9 #include <linux/vmalloc.h> 10 #include <linux/mm.h> 11 #include <asm/cacheflush.h> 12 #include <asm/facility.h> 13 #include <asm/pgalloc.h> 14 #include <asm/kfence.h> 15 #include <asm/page.h> 16 #include <asm/asm.h> 17 #include <asm/set_memory.h> 18 19 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) 20 { 21 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0" 22 : [addr] "+a" (addr) : [skey] "d" (skey)); 23 return addr; 24 } 25 26 void __storage_key_init_range(unsigned long start, unsigned long end) 27 { 28 unsigned long boundary, size; 29 30 while (start < end) { 31 if (cpu_has_edat1()) { 32 /* set storage keys for a 1MB frame */ 33 size = 1UL << 20; 34 boundary = (start + size) & ~(size - 1); 35 if (boundary <= end) { 36 do { 37 start = sske_frame(start, PAGE_DEFAULT_KEY); 38 } while (start < boundary); 39 continue; 40 } 41 } 42 page_set_storage_key(start, PAGE_DEFAULT_KEY, 1); 43 start += PAGE_SIZE; 44 } 45 } 46 47 #ifdef CONFIG_PROC_FS 48 atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]); 49 50 void arch_report_meminfo(struct seq_file *m) 51 { 52 seq_printf(m, "DirectMap4k: %8lu kB\n", 53 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2); 54 seq_printf(m, "DirectMap1M: %8lu kB\n", 55 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10); 56 seq_printf(m, "DirectMap2G: %8lu kB\n", 57 atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21); 58 } 59 #endif /* CONFIG_PROC_FS */ 60 61 static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr, 62 unsigned long dtt) 63 { 64 unsigned long *table, mask; 65 66 mask = 0; 67 if (cpu_has_edat2()) { 68 switch (dtt) { 69 case CRDTE_DTT_REGION3: 70 mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1); 71 break; 72 case CRDTE_DTT_SEGMENT: 73 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); 74 break; 75 case CRDTE_DTT_PAGE: 76 mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1); 77 break; 78 } 79 table = (unsigned long *)((unsigned long)old & mask); 80 crdte(*old, new, table, dtt, addr, get_lowcore()->kernel_asce.val); 81 } else { 82 cspg(old, *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 if (flags == SET_MEMORY_4K) 92 return 0; 93 ptep = pte_offset_kernel(pmdp, addr); 94 do { 95 new = *ptep; 96 if (pte_none(new)) 97 return -EINVAL; 98 if (flags & SET_MEMORY_RO) 99 new = pte_wrprotect(new); 100 else if (flags & SET_MEMORY_RW) 101 new = pte_mkwrite_novma(pte_mkdirty(new)); 102 if (flags & SET_MEMORY_NX) 103 new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC)); 104 else if (flags & SET_MEMORY_X) 105 new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC)); 106 if (flags & SET_MEMORY_INV) { 107 new = set_pte_bit(new, __pgprot(_PAGE_INVALID)); 108 } else if (flags & SET_MEMORY_DEF) { 109 new = __pte(pte_val(new) & PAGE_MASK); 110 new = set_pte_bit(new, PAGE_KERNEL); 111 } 112 pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE); 113 ptep++; 114 addr += PAGE_SIZE; 115 cond_resched(); 116 } while (addr < end); 117 return 0; 118 } 119 120 static int split_pmd_page(pmd_t *pmdp, unsigned long addr) 121 { 122 unsigned long pte_addr, prot; 123 pte_t *pt_dir, *ptep; 124 pmd_t new; 125 int i, ro, nx; 126 127 pt_dir = vmem_pte_alloc(); 128 if (!pt_dir) 129 return -ENOMEM; 130 pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT; 131 ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT); 132 nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC); 133 prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); 134 if (!nx) 135 prot &= ~_PAGE_NOEXEC; 136 ptep = pt_dir; 137 for (i = 0; i < PTRS_PER_PTE; i++) { 138 set_pte(ptep, __pte(pte_addr | prot)); 139 pte_addr += PAGE_SIZE; 140 ptep++; 141 } 142 new = __pmd(__pa(pt_dir) | _SEGMENT_ENTRY); 143 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 144 update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE); 145 update_page_count(PG_DIRECT_MAP_1M, -1); 146 return 0; 147 } 148 149 static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, 150 unsigned long flags) 151 { 152 pmd_t new = *pmdp; 153 154 if (flags & SET_MEMORY_RO) 155 new = pmd_wrprotect(new); 156 else if (flags & SET_MEMORY_RW) 157 new = pmd_mkwrite_novma(pmd_mkdirty(new)); 158 if (flags & SET_MEMORY_NX) 159 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); 160 else if (flags & SET_MEMORY_X) 161 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); 162 if (flags & SET_MEMORY_INV) { 163 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID)); 164 } else if (flags & SET_MEMORY_DEF) { 165 new = __pmd(pmd_val(new) & PMD_MASK); 166 new = set_pmd_bit(new, SEGMENT_KERNEL); 167 } 168 pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); 169 } 170 171 static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, 172 unsigned long flags) 173 { 174 unsigned long next; 175 int need_split; 176 pmd_t *pmdp; 177 int rc = 0; 178 179 pmdp = pmd_offset(pudp, addr); 180 do { 181 if (pmd_none(*pmdp)) 182 return -EINVAL; 183 next = pmd_addr_end(addr, end); 184 if (pmd_leaf(*pmdp)) { 185 need_split = !!(flags & SET_MEMORY_4K); 186 need_split |= !!(addr & ~PMD_MASK); 187 need_split |= !!(addr + PMD_SIZE > next); 188 if (need_split) { 189 rc = split_pmd_page(pmdp, addr); 190 if (rc) 191 return rc; 192 continue; 193 } 194 modify_pmd_page(pmdp, addr, flags); 195 } else { 196 rc = walk_pte_level(pmdp, addr, next, flags); 197 if (rc) 198 return rc; 199 } 200 pmdp++; 201 addr = next; 202 cond_resched(); 203 } while (addr < end); 204 return rc; 205 } 206 207 static int split_pud_page(pud_t *pudp, unsigned long addr) 208 { 209 unsigned long pmd_addr, prot; 210 pmd_t *pm_dir, *pmdp; 211 pud_t new; 212 int i, ro, nx; 213 214 pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); 215 if (!pm_dir) 216 return -ENOMEM; 217 pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT; 218 ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT); 219 nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC); 220 prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); 221 if (!nx) 222 prot &= ~_SEGMENT_ENTRY_NOEXEC; 223 pmdp = pm_dir; 224 for (i = 0; i < PTRS_PER_PMD; i++) { 225 set_pmd(pmdp, __pmd(pmd_addr | prot)); 226 pmd_addr += PMD_SIZE; 227 pmdp++; 228 } 229 new = __pud(__pa(pm_dir) | _REGION3_ENTRY); 230 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 231 update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD); 232 update_page_count(PG_DIRECT_MAP_2G, -1); 233 return 0; 234 } 235 236 static void modify_pud_page(pud_t *pudp, unsigned long addr, 237 unsigned long flags) 238 { 239 pud_t new = *pudp; 240 241 if (flags & SET_MEMORY_RO) 242 new = pud_wrprotect(new); 243 else if (flags & SET_MEMORY_RW) 244 new = pud_mkwrite(pud_mkdirty(new)); 245 if (flags & SET_MEMORY_NX) 246 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); 247 else if (flags & SET_MEMORY_X) 248 new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); 249 if (flags & SET_MEMORY_INV) { 250 new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID)); 251 } else if (flags & SET_MEMORY_DEF) { 252 new = __pud(pud_val(new) & PUD_MASK); 253 new = set_pud_bit(new, REGION3_KERNEL); 254 } 255 pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); 256 } 257 258 static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, 259 unsigned long flags) 260 { 261 unsigned long next; 262 int need_split; 263 pud_t *pudp; 264 int rc = 0; 265 266 pudp = pud_offset(p4d, addr); 267 do { 268 if (pud_none(*pudp)) 269 return -EINVAL; 270 next = pud_addr_end(addr, end); 271 if (pud_leaf(*pudp)) { 272 need_split = !!(flags & SET_MEMORY_4K); 273 need_split |= !!(addr & ~PUD_MASK); 274 need_split |= !!(addr + PUD_SIZE > next); 275 if (need_split) { 276 rc = split_pud_page(pudp, addr); 277 if (rc) 278 break; 279 continue; 280 } 281 modify_pud_page(pudp, addr, flags); 282 } else { 283 rc = walk_pmd_level(pudp, addr, next, flags); 284 } 285 pudp++; 286 addr = next; 287 cond_resched(); 288 } while (addr < end && !rc); 289 return rc; 290 } 291 292 static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end, 293 unsigned long flags) 294 { 295 unsigned long next; 296 p4d_t *p4dp; 297 int rc = 0; 298 299 p4dp = p4d_offset(pgd, addr); 300 do { 301 if (p4d_none(*p4dp)) 302 return -EINVAL; 303 next = p4d_addr_end(addr, end); 304 rc = walk_pud_level(p4dp, addr, next, flags); 305 p4dp++; 306 addr = next; 307 cond_resched(); 308 } while (addr < end && !rc); 309 return rc; 310 } 311 312 DEFINE_MUTEX(cpa_mutex); 313 314 static int change_page_attr(unsigned long addr, unsigned long end, 315 unsigned long flags) 316 { 317 unsigned long next; 318 int rc = -EINVAL; 319 pgd_t *pgdp; 320 321 pgdp = pgd_offset_k(addr); 322 do { 323 if (pgd_none(*pgdp)) 324 break; 325 next = pgd_addr_end(addr, end); 326 rc = walk_p4d_level(pgdp, addr, next, flags); 327 if (rc) 328 break; 329 cond_resched(); 330 } while (pgdp++, addr = next, addr < end && !rc); 331 return rc; 332 } 333 334 static int change_page_attr_alias(unsigned long addr, unsigned long end, 335 unsigned long flags) 336 { 337 unsigned long alias, offset, va_start, va_end; 338 struct vm_struct *area; 339 int rc = 0; 340 341 /* 342 * Changes to read-only permissions on kernel VA mappings are also 343 * applied to the kernel direct mapping. Execute permissions are 344 * intentionally not transferred to keep all allocated pages within 345 * the direct mapping non-executable. 346 */ 347 flags &= SET_MEMORY_RO | SET_MEMORY_RW; 348 if (!flags) 349 return 0; 350 area = NULL; 351 while (addr < end) { 352 if (!area) 353 area = find_vm_area((void *)addr); 354 if (!area || !(area->flags & VM_ALLOC)) 355 return 0; 356 va_start = (unsigned long)area->addr; 357 va_end = va_start + area->nr_pages * PAGE_SIZE; 358 offset = (addr - va_start) >> PAGE_SHIFT; 359 alias = (unsigned long)page_address(area->pages[offset]); 360 rc = change_page_attr(alias, alias + PAGE_SIZE, flags); 361 if (rc) 362 break; 363 addr += PAGE_SIZE; 364 if (addr >= va_end) 365 area = NULL; 366 } 367 return rc; 368 } 369 370 int __set_memory(unsigned long addr, unsigned long numpages, unsigned long flags) 371 { 372 unsigned long end; 373 int rc; 374 375 if (!cpu_has_nx()) 376 flags &= ~(SET_MEMORY_NX | SET_MEMORY_X); 377 if (!flags) 378 return 0; 379 if (!numpages) 380 return 0; 381 addr &= PAGE_MASK; 382 end = addr + numpages * PAGE_SIZE; 383 mutex_lock(&cpa_mutex); 384 rc = change_page_attr(addr, end, flags); 385 if (rc) 386 goto out; 387 rc = change_page_attr_alias(addr, end, flags); 388 out: 389 mutex_unlock(&cpa_mutex); 390 return rc; 391 } 392 393 int set_direct_map_invalid_noflush(struct page *page) 394 { 395 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV); 396 } 397 398 int set_direct_map_default_noflush(struct page *page) 399 { 400 return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF); 401 } 402 403 int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid) 404 { 405 unsigned long flags; 406 407 if (valid) 408 flags = SET_MEMORY_DEF; 409 else 410 flags = SET_MEMORY_INV; 411 412 return __set_memory((unsigned long)page_to_virt(page), nr, flags); 413 } 414 415 bool kernel_page_present(struct page *page) 416 { 417 unsigned long addr; 418 unsigned int cc; 419 420 addr = (unsigned long)page_address(page); 421 asm volatile( 422 " lra %[addr],0(%[addr])\n" 423 CC_IPM(cc) 424 : CC_OUT(cc, cc), [addr] "+a" (addr) 425 : 426 : CC_CLOBBER); 427 return CC_TRANSFORM(cc) == 0; 428 } 429 430 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) 431 432 static void ipte_range(pte_t *pte, unsigned long address, int nr) 433 { 434 int i; 435 436 if (test_facility(13)) { 437 __ptep_ipte_range(address, nr - 1, pte, IPTE_GLOBAL); 438 return; 439 } 440 for (i = 0; i < nr; i++) { 441 __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL); 442 address += PAGE_SIZE; 443 pte++; 444 } 445 } 446 447 void __kernel_map_pages(struct page *page, int numpages, int enable) 448 { 449 unsigned long address; 450 pte_t *ptep, pte; 451 int nr, i, j; 452 453 for (i = 0; i < numpages;) { 454 address = (unsigned long)page_to_virt(page + i); 455 ptep = virt_to_kpte(address); 456 nr = (unsigned long)ptep >> ilog2(sizeof(long)); 457 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); 458 nr = min(numpages - i, nr); 459 if (enable) { 460 for (j = 0; j < nr; j++) { 461 pte = clear_pte_bit(*ptep, __pgprot(_PAGE_INVALID)); 462 set_pte(ptep, pte); 463 address += PAGE_SIZE; 464 ptep++; 465 } 466 } else { 467 ipte_range(ptep, address, nr); 468 } 469 i += nr; 470 } 471 } 472 473 #endif /* CONFIG_DEBUG_PAGEALLOC */ 474