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/pgtable.h> 18 #include <asm/tlb.h> 19 #include <asm/tlbflush.h> 20 #include <asm/cacheflush.h> 21 #include <asm/mmu_context.h> 22 23 /* Slightly simplified from the non-hugepage variant because by 24 * definition we don't have to worry about any page coloring stuff 25 */ 26 27 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp, 28 unsigned long addr, 29 unsigned long len, 30 unsigned long pgoff, 31 unsigned long flags) 32 { 33 struct hstate *h = hstate_file(filp); 34 unsigned long task_size = TASK_SIZE; 35 struct vm_unmapped_area_info info; 36 37 if (test_thread_flag(TIF_32BIT)) 38 task_size = STACK_TOP32; 39 40 info.flags = 0; 41 info.length = len; 42 info.low_limit = TASK_UNMAPPED_BASE; 43 info.high_limit = min(task_size, VA_EXCLUDE_START); 44 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 45 info.align_offset = 0; 46 addr = vm_unmapped_area(&info); 47 48 if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) { 49 VM_BUG_ON(addr != -ENOMEM); 50 info.low_limit = VA_EXCLUDE_END; 51 info.high_limit = task_size; 52 addr = vm_unmapped_area(&info); 53 } 54 55 return addr; 56 } 57 58 static unsigned long 59 hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, 60 const unsigned long len, 61 const unsigned long pgoff, 62 const unsigned long flags) 63 { 64 struct hstate *h = hstate_file(filp); 65 struct mm_struct *mm = current->mm; 66 unsigned long addr = addr0; 67 struct vm_unmapped_area_info info; 68 69 /* This should only ever run for 32-bit processes. */ 70 BUG_ON(!test_thread_flag(TIF_32BIT)); 71 72 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 73 info.length = len; 74 info.low_limit = PAGE_SIZE; 75 info.high_limit = mm->mmap_base; 76 info.align_mask = PAGE_MASK & ~huge_page_mask(h); 77 info.align_offset = 0; 78 addr = vm_unmapped_area(&info); 79 80 /* 81 * A failed mmap() very likely causes application failure, 82 * so fall back to the bottom-up function here. This scenario 83 * can happen with large stack limits and large mmap() 84 * allocations. 85 */ 86 if (addr & ~PAGE_MASK) { 87 VM_BUG_ON(addr != -ENOMEM); 88 info.flags = 0; 89 info.low_limit = TASK_UNMAPPED_BASE; 90 info.high_limit = STACK_TOP32; 91 addr = vm_unmapped_area(&info); 92 } 93 94 return addr; 95 } 96 97 unsigned long 98 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 99 unsigned long len, unsigned long pgoff, unsigned long flags) 100 { 101 struct hstate *h = hstate_file(file); 102 struct mm_struct *mm = current->mm; 103 struct vm_area_struct *vma; 104 unsigned long task_size = TASK_SIZE; 105 106 if (test_thread_flag(TIF_32BIT)) 107 task_size = STACK_TOP32; 108 109 if (len & ~huge_page_mask(h)) 110 return -EINVAL; 111 if (len > task_size) 112 return -ENOMEM; 113 114 if (flags & MAP_FIXED) { 115 if (prepare_hugepage_range(file, addr, len)) 116 return -EINVAL; 117 return addr; 118 } 119 120 if (addr) { 121 addr = ALIGN(addr, huge_page_size(h)); 122 vma = find_vma(mm, addr); 123 if (task_size - len >= addr && 124 (!vma || addr + len <= vm_start_gap(vma))) 125 return addr; 126 } 127 if (mm->get_unmapped_area == arch_get_unmapped_area) 128 return hugetlb_get_unmapped_area_bottomup(file, addr, len, 129 pgoff, flags); 130 else 131 return hugetlb_get_unmapped_area_topdown(file, addr, len, 132 pgoff, flags); 133 } 134 135 static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift) 136 { 137 return entry; 138 } 139 140 static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift) 141 { 142 unsigned long hugepage_size = _PAGE_SZ4MB_4V; 143 144 pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V; 145 146 switch (shift) { 147 case HPAGE_16GB_SHIFT: 148 hugepage_size = _PAGE_SZ16GB_4V; 149 pte_val(entry) |= _PAGE_PUD_HUGE; 150 break; 151 case HPAGE_2GB_SHIFT: 152 hugepage_size = _PAGE_SZ2GB_4V; 153 pte_val(entry) |= _PAGE_PMD_HUGE; 154 break; 155 case HPAGE_256MB_SHIFT: 156 hugepage_size = _PAGE_SZ256MB_4V; 157 pte_val(entry) |= _PAGE_PMD_HUGE; 158 break; 159 case HPAGE_SHIFT: 160 pte_val(entry) |= _PAGE_PMD_HUGE; 161 break; 162 case HPAGE_64K_SHIFT: 163 hugepage_size = _PAGE_SZ64K_4V; 164 break; 165 default: 166 WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift); 167 } 168 169 pte_val(entry) = pte_val(entry) | hugepage_size; 170 return entry; 171 } 172 173 static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift) 174 { 175 if (tlb_type == hypervisor) 176 return sun4v_hugepage_shift_to_tte(entry, shift); 177 else 178 return sun4u_hugepage_shift_to_tte(entry, shift); 179 } 180 181 pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, 182 struct page *page, int writeable) 183 { 184 unsigned int shift = huge_page_shift(hstate_vma(vma)); 185 pte_t pte; 186 187 pte = hugepage_shift_to_tte(entry, shift); 188 189 #ifdef CONFIG_SPARC64 190 /* If this vma has ADI enabled on it, turn on TTE.mcd 191 */ 192 if (vma->vm_flags & VM_SPARC_ADI) 193 return pte_mkmcd(pte); 194 else 195 return pte_mknotmcd(pte); 196 #else 197 return pte; 198 #endif 199 } 200 201 static unsigned int sun4v_huge_tte_to_shift(pte_t entry) 202 { 203 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V; 204 unsigned int shift; 205 206 switch (tte_szbits) { 207 case _PAGE_SZ16GB_4V: 208 shift = HPAGE_16GB_SHIFT; 209 break; 210 case _PAGE_SZ2GB_4V: 211 shift = HPAGE_2GB_SHIFT; 212 break; 213 case _PAGE_SZ256MB_4V: 214 shift = HPAGE_256MB_SHIFT; 215 break; 216 case _PAGE_SZ4MB_4V: 217 shift = REAL_HPAGE_SHIFT; 218 break; 219 case _PAGE_SZ64K_4V: 220 shift = HPAGE_64K_SHIFT; 221 break; 222 default: 223 shift = PAGE_SHIFT; 224 break; 225 } 226 return shift; 227 } 228 229 static unsigned int sun4u_huge_tte_to_shift(pte_t entry) 230 { 231 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U; 232 unsigned int shift; 233 234 switch (tte_szbits) { 235 case _PAGE_SZ256MB_4U: 236 shift = HPAGE_256MB_SHIFT; 237 break; 238 case _PAGE_SZ4MB_4U: 239 shift = REAL_HPAGE_SHIFT; 240 break; 241 case _PAGE_SZ64K_4U: 242 shift = HPAGE_64K_SHIFT; 243 break; 244 default: 245 shift = PAGE_SHIFT; 246 break; 247 } 248 return shift; 249 } 250 251 static unsigned int huge_tte_to_shift(pte_t entry) 252 { 253 unsigned long shift; 254 255 if (tlb_type == hypervisor) 256 shift = sun4v_huge_tte_to_shift(entry); 257 else 258 shift = sun4u_huge_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 pte_t *huge_pte_alloc(struct mm_struct *mm, 277 unsigned long addr, unsigned long sz) 278 { 279 pgd_t *pgd; 280 p4d_t *p4d; 281 pud_t *pud; 282 pmd_t *pmd; 283 284 pgd = pgd_offset(mm, addr); 285 p4d = p4d_offset(pgd, addr); 286 pud = pud_alloc(mm, p4d, addr); 287 if (!pud) 288 return NULL; 289 if (sz >= PUD_SIZE) 290 return (pte_t *)pud; 291 pmd = pmd_alloc(mm, pud, addr); 292 if (!pmd) 293 return NULL; 294 if (sz >= PMD_SIZE) 295 return (pte_t *)pmd; 296 return pte_alloc_map(mm, pmd, addr); 297 } 298 299 pte_t *huge_pte_offset(struct mm_struct *mm, 300 unsigned long addr, unsigned long sz) 301 { 302 pgd_t *pgd; 303 p4d_t *p4d; 304 pud_t *pud; 305 pmd_t *pmd; 306 307 pgd = pgd_offset(mm, addr); 308 if (pgd_none(*pgd)) 309 return NULL; 310 p4d = p4d_offset(pgd, addr); 311 if (p4d_none(*p4d)) 312 return NULL; 313 pud = pud_offset(p4d, addr); 314 if (pud_none(*pud)) 315 return NULL; 316 if (is_hugetlb_pud(*pud)) 317 return (pte_t *)pud; 318 pmd = pmd_offset(pud, addr); 319 if (pmd_none(*pmd)) 320 return NULL; 321 if (is_hugetlb_pmd(*pmd)) 322 return (pte_t *)pmd; 323 return pte_offset_map(pmd, addr); 324 } 325 326 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 327 pte_t *ptep, pte_t entry) 328 { 329 unsigned int nptes, orig_shift, shift; 330 unsigned long i, size; 331 pte_t orig; 332 333 size = huge_tte_to_size(entry); 334 335 shift = PAGE_SHIFT; 336 if (size >= PUD_SIZE) 337 shift = PUD_SHIFT; 338 else if (size >= PMD_SIZE) 339 shift = PMD_SHIFT; 340 else 341 shift = PAGE_SHIFT; 342 343 nptes = size >> shift; 344 345 if (!pte_present(*ptep) && pte_present(entry)) 346 mm->context.hugetlb_pte_count += nptes; 347 348 addr &= ~(size - 1); 349 orig = *ptep; 350 orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig); 351 352 for (i = 0; i < nptes; i++) 353 ptep[i] = __pte(pte_val(entry) + (i << shift)); 354 355 maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift); 356 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */ 357 if (size == HPAGE_SIZE) 358 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0, 359 orig_shift); 360 } 361 362 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 363 pte_t *ptep) 364 { 365 unsigned int i, nptes, orig_shift, shift; 366 unsigned long size; 367 pte_t entry; 368 369 entry = *ptep; 370 size = huge_tte_to_size(entry); 371 372 shift = PAGE_SHIFT; 373 if (size >= PUD_SIZE) 374 shift = PUD_SHIFT; 375 else if (size >= PMD_SIZE) 376 shift = PMD_SHIFT; 377 else 378 shift = PAGE_SHIFT; 379 380 nptes = size >> shift; 381 orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry); 382 383 if (pte_present(entry)) 384 mm->context.hugetlb_pte_count -= nptes; 385 386 addr &= ~(size - 1); 387 for (i = 0; i < nptes; i++) 388 ptep[i] = __pte(0UL); 389 390 maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift); 391 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */ 392 if (size == HPAGE_SIZE) 393 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0, 394 orig_shift); 395 396 return entry; 397 } 398 399 int pmd_huge(pmd_t pmd) 400 { 401 return !pmd_none(pmd) && 402 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID; 403 } 404 405 int pud_huge(pud_t pud) 406 { 407 return !pud_none(pud) && 408 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID; 409 } 410 411 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd, 412 unsigned long addr) 413 { 414 pgtable_t token = pmd_pgtable(*pmd); 415 416 pmd_clear(pmd); 417 pte_free_tlb(tlb, token, addr); 418 mm_dec_nr_ptes(tlb->mm); 419 } 420 421 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 422 unsigned long addr, unsigned long end, 423 unsigned long floor, unsigned long ceiling) 424 { 425 pmd_t *pmd; 426 unsigned long next; 427 unsigned long start; 428 429 start = addr; 430 pmd = pmd_offset(pud, addr); 431 do { 432 next = pmd_addr_end(addr, end); 433 if (pmd_none(*pmd)) 434 continue; 435 if (is_hugetlb_pmd(*pmd)) 436 pmd_clear(pmd); 437 else 438 hugetlb_free_pte_range(tlb, pmd, addr); 439 } while (pmd++, addr = next, addr != end); 440 441 start &= PUD_MASK; 442 if (start < floor) 443 return; 444 if (ceiling) { 445 ceiling &= PUD_MASK; 446 if (!ceiling) 447 return; 448 } 449 if (end - 1 > ceiling - 1) 450 return; 451 452 pmd = pmd_offset(pud, start); 453 pud_clear(pud); 454 pmd_free_tlb(tlb, pmd, start); 455 mm_dec_nr_pmds(tlb->mm); 456 } 457 458 static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d, 459 unsigned long addr, unsigned long end, 460 unsigned long floor, unsigned long ceiling) 461 { 462 pud_t *pud; 463 unsigned long next; 464 unsigned long start; 465 466 start = addr; 467 pud = pud_offset(p4d, addr); 468 do { 469 next = pud_addr_end(addr, end); 470 if (pud_none_or_clear_bad(pud)) 471 continue; 472 if (is_hugetlb_pud(*pud)) 473 pud_clear(pud); 474 else 475 hugetlb_free_pmd_range(tlb, pud, addr, next, floor, 476 ceiling); 477 } while (pud++, addr = next, addr != end); 478 479 start &= PGDIR_MASK; 480 if (start < floor) 481 return; 482 if (ceiling) { 483 ceiling &= PGDIR_MASK; 484 if (!ceiling) 485 return; 486 } 487 if (end - 1 > ceiling - 1) 488 return; 489 490 pud = pud_offset(p4d, start); 491 p4d_clear(p4d); 492 pud_free_tlb(tlb, pud, start); 493 mm_dec_nr_puds(tlb->mm); 494 } 495 496 void hugetlb_free_pgd_range(struct mmu_gather *tlb, 497 unsigned long addr, unsigned long end, 498 unsigned long floor, unsigned long ceiling) 499 { 500 pgd_t *pgd; 501 p4d_t *p4d; 502 unsigned long next; 503 504 addr &= PMD_MASK; 505 if (addr < floor) { 506 addr += PMD_SIZE; 507 if (!addr) 508 return; 509 } 510 if (ceiling) { 511 ceiling &= PMD_MASK; 512 if (!ceiling) 513 return; 514 } 515 if (end - 1 > ceiling - 1) 516 end -= PMD_SIZE; 517 if (addr > end - 1) 518 return; 519 520 pgd = pgd_offset(tlb->mm, addr); 521 p4d = p4d_offset(pgd, addr); 522 do { 523 next = p4d_addr_end(addr, end); 524 if (p4d_none_or_clear_bad(p4d)) 525 continue; 526 hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling); 527 } while (p4d++, addr = next, addr != end); 528 } 529