1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SPARC64 Huge TLB page support. 4 * 5 * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net) 6 */ 7 8 #include <linux/fs.h> 9 #include <linux/mm.h> 10 #include <linux/sched/mm.h> 11 #include <linux/hugetlb.h> 12 #include <linux/pagemap.h> 13 #include <linux/sysctl.h> 14 15 #include <asm/mman.h> 16 #include <asm/pgalloc.h> 17 #include <asm/tlb.h> 18 #include <asm/tlbflush.h> 19 #include <asm/cacheflush.h> 20 #include <asm/mmu_context.h> 21 22 /* Slightly simplified from the non-hugepage variant because by 23 * definition we don't have to worry about any page coloring stuff 24 */ 25 26 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp, 27 unsigned long addr, 28 unsigned long len, 29 unsigned long pgoff, 30 unsigned long flags) 31 { 32 struct hstate *h = hstate_file(filp); 33 unsigned long task_size = TASK_SIZE; 34 struct vm_unmapped_area_info info; 35 36 if (test_thread_flag(TIF_32BIT)) 37 task_size = STACK_TOP32; 38 39 info.flags = 0; 40 info.length = len; 41 info.low_limit = TASK_UNMAPPED_BASE; 42 info.high_limit = min(task_size, VA_EXCLUDE_START); 43 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 44 info.align_offset = 0; 45 addr = vm_unmapped_area(&info); 46 47 if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) { 48 VM_BUG_ON(addr != -ENOMEM); 49 info.low_limit = VA_EXCLUDE_END; 50 info.high_limit = task_size; 51 addr = vm_unmapped_area(&info); 52 } 53 54 return addr; 55 } 56 57 static unsigned long 58 hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, 59 const unsigned long len, 60 const unsigned long pgoff, 61 const unsigned long flags) 62 { 63 struct hstate *h = hstate_file(filp); 64 struct mm_struct *mm = current->mm; 65 unsigned long addr = addr0; 66 struct vm_unmapped_area_info info; 67 68 /* This should only ever run for 32-bit processes. */ 69 BUG_ON(!test_thread_flag(TIF_32BIT)); 70 71 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 72 info.length = len; 73 info.low_limit = PAGE_SIZE; 74 info.high_limit = mm->mmap_base; 75 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 76 info.align_offset = 0; 77 addr = vm_unmapped_area(&info); 78 79 /* 80 * A failed mmap() very likely causes application failure, 81 * so fall back to the bottom-up function here. This scenario 82 * can happen with large stack limits and large mmap() 83 * allocations. 84 */ 85 if (addr & ~PAGE_MASK) { 86 VM_BUG_ON(addr != -ENOMEM); 87 info.flags = 0; 88 info.low_limit = TASK_UNMAPPED_BASE; 89 info.high_limit = STACK_TOP32; 90 addr = vm_unmapped_area(&info); 91 } 92 93 return addr; 94 } 95 96 unsigned long 97 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 98 unsigned long len, unsigned long pgoff, unsigned long flags) 99 { 100 struct hstate *h = hstate_file(file); 101 struct mm_struct *mm = current->mm; 102 struct vm_area_struct *vma; 103 unsigned long task_size = TASK_SIZE; 104 105 if (test_thread_flag(TIF_32BIT)) 106 task_size = STACK_TOP32; 107 108 if (len & ~huge_page_mask(h)) 109 return -EINVAL; 110 if (len > task_size) 111 return -ENOMEM; 112 113 if (flags & MAP_FIXED) { 114 if (prepare_hugepage_range(file, addr, len)) 115 return -EINVAL; 116 return addr; 117 } 118 119 if (addr) { 120 addr = ALIGN(addr, huge_page_size(h)); 121 vma = find_vma(mm, addr); 122 if (task_size - len >= addr && 123 (!vma || addr + len <= vm_start_gap(vma))) 124 return addr; 125 } 126 if (mm->get_unmapped_area == arch_get_unmapped_area) 127 return hugetlb_get_unmapped_area_bottomup(file, addr, len, 128 pgoff, flags); 129 else 130 return hugetlb_get_unmapped_area_topdown(file, addr, len, 131 pgoff, flags); 132 } 133 134 static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift) 135 { 136 return entry; 137 } 138 139 static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift) 140 { 141 unsigned long hugepage_size = _PAGE_SZ4MB_4V; 142 143 pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V; 144 145 switch (shift) { 146 case HPAGE_16GB_SHIFT: 147 hugepage_size = _PAGE_SZ16GB_4V; 148 pte_val(entry) |= _PAGE_PUD_HUGE; 149 break; 150 case HPAGE_2GB_SHIFT: 151 hugepage_size = _PAGE_SZ2GB_4V; 152 pte_val(entry) |= _PAGE_PMD_HUGE; 153 break; 154 case HPAGE_256MB_SHIFT: 155 hugepage_size = _PAGE_SZ256MB_4V; 156 pte_val(entry) |= _PAGE_PMD_HUGE; 157 break; 158 case HPAGE_SHIFT: 159 pte_val(entry) |= _PAGE_PMD_HUGE; 160 break; 161 case HPAGE_64K_SHIFT: 162 hugepage_size = _PAGE_SZ64K_4V; 163 break; 164 default: 165 WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift); 166 } 167 168 pte_val(entry) = pte_val(entry) | hugepage_size; 169 return entry; 170 } 171 172 static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift) 173 { 174 if (tlb_type == hypervisor) 175 return sun4v_hugepage_shift_to_tte(entry, shift); 176 else 177 return sun4u_hugepage_shift_to_tte(entry, shift); 178 } 179 180 pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags) 181 { 182 pte_t pte; 183 184 pte = hugepage_shift_to_tte(entry, shift); 185 186 #ifdef CONFIG_SPARC64 187 /* If this vma has ADI enabled on it, turn on TTE.mcd 188 */ 189 if (flags & VM_SPARC_ADI) 190 return pte_mkmcd(pte); 191 else 192 return pte_mknotmcd(pte); 193 #else 194 return pte; 195 #endif 196 } 197 198 static unsigned int sun4v_huge_tte_to_shift(pte_t entry) 199 { 200 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V; 201 unsigned int shift; 202 203 switch (tte_szbits) { 204 case _PAGE_SZ16GB_4V: 205 shift = HPAGE_16GB_SHIFT; 206 break; 207 case _PAGE_SZ2GB_4V: 208 shift = HPAGE_2GB_SHIFT; 209 break; 210 case _PAGE_SZ256MB_4V: 211 shift = HPAGE_256MB_SHIFT; 212 break; 213 case _PAGE_SZ4MB_4V: 214 shift = REAL_HPAGE_SHIFT; 215 break; 216 case _PAGE_SZ64K_4V: 217 shift = HPAGE_64K_SHIFT; 218 break; 219 default: 220 shift = PAGE_SHIFT; 221 break; 222 } 223 return shift; 224 } 225 226 static unsigned int sun4u_huge_tte_to_shift(pte_t entry) 227 { 228 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U; 229 unsigned int shift; 230 231 switch (tte_szbits) { 232 case _PAGE_SZ256MB_4U: 233 shift = HPAGE_256MB_SHIFT; 234 break; 235 case _PAGE_SZ4MB_4U: 236 shift = REAL_HPAGE_SHIFT; 237 break; 238 case _PAGE_SZ64K_4U: 239 shift = HPAGE_64K_SHIFT; 240 break; 241 default: 242 shift = PAGE_SHIFT; 243 break; 244 } 245 return shift; 246 } 247 248 static unsigned long tte_to_shift(pte_t entry) 249 { 250 if (tlb_type == hypervisor) 251 return sun4v_huge_tte_to_shift(entry); 252 253 return sun4u_huge_tte_to_shift(entry); 254 } 255 256 static unsigned int huge_tte_to_shift(pte_t entry) 257 { 258 unsigned long shift = tte_to_shift(entry); 259 260 if (shift == PAGE_SHIFT) 261 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n", 262 pte_val(entry)); 263 264 return shift; 265 } 266 267 static unsigned long huge_tte_to_size(pte_t pte) 268 { 269 unsigned long size = 1UL << huge_tte_to_shift(pte); 270 271 if (size == REAL_HPAGE_SIZE) 272 size = HPAGE_SIZE; 273 return size; 274 } 275 276 unsigned long pud_leaf_size(pud_t pud) { return 1UL << tte_to_shift(*(pte_t *)&pud); } 277 unsigned long pmd_leaf_size(pmd_t pmd) { return 1UL << tte_to_shift(*(pte_t *)&pmd); } 278 unsigned long pte_leaf_size(pte_t pte) { return 1UL << tte_to_shift(pte); } 279 280 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 281 unsigned long addr, unsigned long sz) 282 { 283 pgd_t *pgd; 284 p4d_t *p4d; 285 pud_t *pud; 286 pmd_t *pmd; 287 288 pgd = pgd_offset(mm, addr); 289 p4d = p4d_offset(pgd, addr); 290 pud = pud_alloc(mm, p4d, addr); 291 if (!pud) 292 return NULL; 293 if (sz >= PUD_SIZE) 294 return (pte_t *)pud; 295 pmd = pmd_alloc(mm, pud, addr); 296 if (!pmd) 297 return NULL; 298 if (sz >= PMD_SIZE) 299 return (pte_t *)pmd; 300 return pte_alloc_map(mm, pmd, addr); 301 } 302 303 pte_t *huge_pte_offset(struct mm_struct *mm, 304 unsigned long addr, unsigned long sz) 305 { 306 pgd_t *pgd; 307 p4d_t *p4d; 308 pud_t *pud; 309 pmd_t *pmd; 310 311 pgd = pgd_offset(mm, addr); 312 if (pgd_none(*pgd)) 313 return NULL; 314 p4d = p4d_offset(pgd, addr); 315 if (p4d_none(*p4d)) 316 return NULL; 317 pud = pud_offset(p4d, addr); 318 if (pud_none(*pud)) 319 return NULL; 320 if (is_hugetlb_pud(*pud)) 321 return (pte_t *)pud; 322 pmd = pmd_offset(pud, addr); 323 if (pmd_none(*pmd)) 324 return NULL; 325 if (is_hugetlb_pmd(*pmd)) 326 return (pte_t *)pmd; 327 return pte_offset_map(pmd, addr); 328 } 329 330 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 331 pte_t *ptep, pte_t entry) 332 { 333 unsigned int nptes, orig_shift, shift; 334 unsigned long i, size; 335 pte_t orig; 336 337 size = huge_tte_to_size(entry); 338 339 shift = PAGE_SHIFT; 340 if (size >= PUD_SIZE) 341 shift = PUD_SHIFT; 342 else if (size >= PMD_SIZE) 343 shift = PMD_SHIFT; 344 else 345 shift = PAGE_SHIFT; 346 347 nptes = size >> shift; 348 349 if (!pte_present(*ptep) && pte_present(entry)) 350 mm->context.hugetlb_pte_count += nptes; 351 352 addr &= ~(size - 1); 353 orig = *ptep; 354 orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig); 355 356 for (i = 0; i < nptes; i++) 357 ptep[i] = __pte(pte_val(entry) + (i << shift)); 358 359 maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift); 360 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */ 361 if (size == HPAGE_SIZE) 362 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0, 363 orig_shift); 364 } 365 366 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 367 pte_t *ptep) 368 { 369 unsigned int i, nptes, orig_shift, shift; 370 unsigned long size; 371 pte_t entry; 372 373 entry = *ptep; 374 size = huge_tte_to_size(entry); 375 376 shift = PAGE_SHIFT; 377 if (size >= PUD_SIZE) 378 shift = PUD_SHIFT; 379 else if (size >= PMD_SIZE) 380 shift = PMD_SHIFT; 381 else 382 shift = PAGE_SHIFT; 383 384 nptes = size >> shift; 385 orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry); 386 387 if (pte_present(entry)) 388 mm->context.hugetlb_pte_count -= nptes; 389 390 addr &= ~(size - 1); 391 for (i = 0; i < nptes; i++) 392 ptep[i] = __pte(0UL); 393 394 maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift); 395 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */ 396 if (size == HPAGE_SIZE) 397 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0, 398 orig_shift); 399 400 return entry; 401 } 402 403 int pmd_huge(pmd_t pmd) 404 { 405 return !pmd_none(pmd) && 406 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID; 407 } 408 409 int pud_huge(pud_t pud) 410 { 411 return !pud_none(pud) && 412 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID; 413 } 414 415 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd, 416 unsigned long addr) 417 { 418 pgtable_t token = pmd_pgtable(*pmd); 419 420 pmd_clear(pmd); 421 pte_free_tlb(tlb, token, addr); 422 mm_dec_nr_ptes(tlb->mm); 423 } 424 425 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 426 unsigned long addr, unsigned long end, 427 unsigned long floor, unsigned long ceiling) 428 { 429 pmd_t *pmd; 430 unsigned long next; 431 unsigned long start; 432 433 start = addr; 434 pmd = pmd_offset(pud, addr); 435 do { 436 next = pmd_addr_end(addr, end); 437 if (pmd_none(*pmd)) 438 continue; 439 if (is_hugetlb_pmd(*pmd)) 440 pmd_clear(pmd); 441 else 442 hugetlb_free_pte_range(tlb, pmd, addr); 443 } while (pmd++, addr = next, addr != end); 444 445 start &= PUD_MASK; 446 if (start < floor) 447 return; 448 if (ceiling) { 449 ceiling &= PUD_MASK; 450 if (!ceiling) 451 return; 452 } 453 if (end - 1 > ceiling - 1) 454 return; 455 456 pmd = pmd_offset(pud, start); 457 pud_clear(pud); 458 pmd_free_tlb(tlb, pmd, start); 459 mm_dec_nr_pmds(tlb->mm); 460 } 461 462 static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d, 463 unsigned long addr, unsigned long end, 464 unsigned long floor, unsigned long ceiling) 465 { 466 pud_t *pud; 467 unsigned long next; 468 unsigned long start; 469 470 start = addr; 471 pud = pud_offset(p4d, addr); 472 do { 473 next = pud_addr_end(addr, end); 474 if (pud_none_or_clear_bad(pud)) 475 continue; 476 if (is_hugetlb_pud(*pud)) 477 pud_clear(pud); 478 else 479 hugetlb_free_pmd_range(tlb, pud, addr, next, floor, 480 ceiling); 481 } while (pud++, addr = next, addr != end); 482 483 start &= PGDIR_MASK; 484 if (start < floor) 485 return; 486 if (ceiling) { 487 ceiling &= PGDIR_MASK; 488 if (!ceiling) 489 return; 490 } 491 if (end - 1 > ceiling - 1) 492 return; 493 494 pud = pud_offset(p4d, start); 495 p4d_clear(p4d); 496 pud_free_tlb(tlb, pud, start); 497 mm_dec_nr_puds(tlb->mm); 498 } 499 500 void hugetlb_free_pgd_range(struct mmu_gather *tlb, 501 unsigned long addr, unsigned long end, 502 unsigned long floor, unsigned long ceiling) 503 { 504 pgd_t *pgd; 505 p4d_t *p4d; 506 unsigned long next; 507 508 addr &= PMD_MASK; 509 if (addr < floor) { 510 addr += PMD_SIZE; 511 if (!addr) 512 return; 513 } 514 if (ceiling) { 515 ceiling &= PMD_MASK; 516 if (!ceiling) 517 return; 518 } 519 if (end - 1 > ceiling - 1) 520 end -= PMD_SIZE; 521 if (addr > end - 1) 522 return; 523 524 pgd = pgd_offset(tlb->mm, addr); 525 p4d = p4d_offset(pgd, addr); 526 do { 527 next = p4d_addr_end(addr, end); 528 if (p4d_none_or_clear_bad(p4d)) 529 continue; 530 hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling); 531 } while (p4d++, addr = next, addr != end); 532 } 533