1 /* 2 * SPARC64 Huge TLB page support. 3 * 4 * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net) 5 */ 6 7 #include <linux/fs.h> 8 #include <linux/mm.h> 9 #include <linux/sched/mm.h> 10 #include <linux/hugetlb.h> 11 #include <linux/pagemap.h> 12 #include <linux/sysctl.h> 13 14 #include <asm/mman.h> 15 #include <asm/pgalloc.h> 16 #include <asm/pgtable.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 <= vma->vm_start)) 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_256MB_SHIFT: 147 hugepage_size = _PAGE_SZ256MB_4V; 148 pte_val(entry) |= _PAGE_PMD_HUGE; 149 break; 150 case HPAGE_SHIFT: 151 pte_val(entry) |= _PAGE_PMD_HUGE; 152 break; 153 case HPAGE_64K_SHIFT: 154 hugepage_size = _PAGE_SZ64K_4V; 155 break; 156 default: 157 WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift); 158 } 159 160 pte_val(entry) = pte_val(entry) | hugepage_size; 161 return entry; 162 } 163 164 static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift) 165 { 166 if (tlb_type == hypervisor) 167 return sun4v_hugepage_shift_to_tte(entry, shift); 168 else 169 return sun4u_hugepage_shift_to_tte(entry, shift); 170 } 171 172 pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, 173 struct page *page, int writeable) 174 { 175 unsigned int shift = huge_page_shift(hstate_vma(vma)); 176 177 return hugepage_shift_to_tte(entry, shift); 178 } 179 180 static unsigned int sun4v_huge_tte_to_shift(pte_t entry) 181 { 182 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V; 183 unsigned int shift; 184 185 switch (tte_szbits) { 186 case _PAGE_SZ256MB_4V: 187 shift = HPAGE_256MB_SHIFT; 188 break; 189 case _PAGE_SZ4MB_4V: 190 shift = REAL_HPAGE_SHIFT; 191 break; 192 case _PAGE_SZ64K_4V: 193 shift = HPAGE_64K_SHIFT; 194 break; 195 default: 196 shift = PAGE_SHIFT; 197 break; 198 } 199 return shift; 200 } 201 202 static unsigned int sun4u_huge_tte_to_shift(pte_t entry) 203 { 204 unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U; 205 unsigned int shift; 206 207 switch (tte_szbits) { 208 case _PAGE_SZ256MB_4U: 209 shift = HPAGE_256MB_SHIFT; 210 break; 211 case _PAGE_SZ4MB_4U: 212 shift = REAL_HPAGE_SHIFT; 213 break; 214 case _PAGE_SZ64K_4U: 215 shift = HPAGE_64K_SHIFT; 216 break; 217 default: 218 shift = PAGE_SHIFT; 219 break; 220 } 221 return shift; 222 } 223 224 static unsigned int huge_tte_to_shift(pte_t entry) 225 { 226 unsigned long shift; 227 228 if (tlb_type == hypervisor) 229 shift = sun4v_huge_tte_to_shift(entry); 230 else 231 shift = sun4u_huge_tte_to_shift(entry); 232 233 if (shift == PAGE_SHIFT) 234 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n", 235 pte_val(entry)); 236 237 return shift; 238 } 239 240 static unsigned long huge_tte_to_size(pte_t pte) 241 { 242 unsigned long size = 1UL << huge_tte_to_shift(pte); 243 244 if (size == REAL_HPAGE_SIZE) 245 size = HPAGE_SIZE; 246 return size; 247 } 248 249 pte_t *huge_pte_alloc(struct mm_struct *mm, 250 unsigned long addr, unsigned long sz) 251 { 252 pgd_t *pgd; 253 pud_t *pud; 254 pmd_t *pmd; 255 pte_t *pte = NULL; 256 257 pgd = pgd_offset(mm, addr); 258 pud = pud_alloc(mm, pgd, addr); 259 if (pud) { 260 pmd = pmd_alloc(mm, pud, addr); 261 if (!pmd) 262 return NULL; 263 264 if (sz == PMD_SHIFT) 265 pte = (pte_t *)pmd; 266 else 267 pte = pte_alloc_map(mm, pmd, addr); 268 } 269 270 return pte; 271 } 272 273 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) 274 { 275 pgd_t *pgd; 276 pud_t *pud; 277 pmd_t *pmd; 278 pte_t *pte = NULL; 279 280 pgd = pgd_offset(mm, addr); 281 if (!pgd_none(*pgd)) { 282 pud = pud_offset(pgd, addr); 283 if (!pud_none(*pud)) { 284 pmd = pmd_offset(pud, addr); 285 if (!pmd_none(*pmd)) { 286 if (is_hugetlb_pmd(*pmd)) 287 pte = (pte_t *)pmd; 288 else 289 pte = pte_offset_map(pmd, addr); 290 } 291 } 292 } 293 294 return pte; 295 } 296 297 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 298 pte_t *ptep, pte_t entry) 299 { 300 unsigned int i, nptes, orig_shift, shift; 301 unsigned long size; 302 pte_t orig; 303 304 size = huge_tte_to_size(entry); 305 shift = size >= HPAGE_SIZE ? PMD_SHIFT : PAGE_SHIFT; 306 nptes = size >> shift; 307 308 if (!pte_present(*ptep) && pte_present(entry)) 309 mm->context.hugetlb_pte_count += nptes; 310 311 addr &= ~(size - 1); 312 orig = *ptep; 313 orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig); 314 315 for (i = 0; i < nptes; i++) 316 ptep[i] = __pte(pte_val(entry) + (i << shift)); 317 318 maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift); 319 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */ 320 if (size == HPAGE_SIZE) 321 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0, 322 orig_shift); 323 } 324 325 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 326 pte_t *ptep) 327 { 328 unsigned int i, nptes, hugepage_shift; 329 unsigned long size; 330 pte_t entry; 331 332 entry = *ptep; 333 size = huge_tte_to_size(entry); 334 if (size >= HPAGE_SIZE) 335 nptes = size >> PMD_SHIFT; 336 else 337 nptes = size >> PAGE_SHIFT; 338 339 hugepage_shift = pte_none(entry) ? PAGE_SHIFT : 340 huge_tte_to_shift(entry); 341 342 if (pte_present(entry)) 343 mm->context.hugetlb_pte_count -= nptes; 344 345 addr &= ~(size - 1); 346 for (i = 0; i < nptes; i++) 347 ptep[i] = __pte(0UL); 348 349 maybe_tlb_batch_add(mm, addr, ptep, entry, 0, hugepage_shift); 350 /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */ 351 if (size == HPAGE_SIZE) 352 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0, 353 hugepage_shift); 354 355 return entry; 356 } 357 358 int pmd_huge(pmd_t pmd) 359 { 360 return !pmd_none(pmd) && 361 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID; 362 } 363 364 int pud_huge(pud_t pud) 365 { 366 return 0; 367 } 368 369 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd, 370 unsigned long addr) 371 { 372 pgtable_t token = pmd_pgtable(*pmd); 373 374 pmd_clear(pmd); 375 pte_free_tlb(tlb, token, addr); 376 atomic_long_dec(&tlb->mm->nr_ptes); 377 } 378 379 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 380 unsigned long addr, unsigned long end, 381 unsigned long floor, unsigned long ceiling) 382 { 383 pmd_t *pmd; 384 unsigned long next; 385 unsigned long start; 386 387 start = addr; 388 pmd = pmd_offset(pud, addr); 389 do { 390 next = pmd_addr_end(addr, end); 391 if (pmd_none(*pmd)) 392 continue; 393 if (is_hugetlb_pmd(*pmd)) 394 pmd_clear(pmd); 395 else 396 hugetlb_free_pte_range(tlb, pmd, addr); 397 } while (pmd++, addr = next, addr != end); 398 399 start &= PUD_MASK; 400 if (start < floor) 401 return; 402 if (ceiling) { 403 ceiling &= PUD_MASK; 404 if (!ceiling) 405 return; 406 } 407 if (end - 1 > ceiling - 1) 408 return; 409 410 pmd = pmd_offset(pud, start); 411 pud_clear(pud); 412 pmd_free_tlb(tlb, pmd, start); 413 mm_dec_nr_pmds(tlb->mm); 414 } 415 416 static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, 417 unsigned long addr, unsigned long end, 418 unsigned long floor, unsigned long ceiling) 419 { 420 pud_t *pud; 421 unsigned long next; 422 unsigned long start; 423 424 start = addr; 425 pud = pud_offset(pgd, addr); 426 do { 427 next = pud_addr_end(addr, end); 428 if (pud_none_or_clear_bad(pud)) 429 continue; 430 hugetlb_free_pmd_range(tlb, pud, addr, next, floor, 431 ceiling); 432 } while (pud++, addr = next, addr != end); 433 434 start &= PGDIR_MASK; 435 if (start < floor) 436 return; 437 if (ceiling) { 438 ceiling &= PGDIR_MASK; 439 if (!ceiling) 440 return; 441 } 442 if (end - 1 > ceiling - 1) 443 return; 444 445 pud = pud_offset(pgd, start); 446 pgd_clear(pgd); 447 pud_free_tlb(tlb, pud, start); 448 } 449 450 void hugetlb_free_pgd_range(struct mmu_gather *tlb, 451 unsigned long addr, unsigned long end, 452 unsigned long floor, unsigned long ceiling) 453 { 454 pgd_t *pgd; 455 unsigned long next; 456 457 pgd = pgd_offset(tlb->mm, addr); 458 do { 459 next = pgd_addr_end(addr, end); 460 if (pgd_none_or_clear_bad(pgd)) 461 continue; 462 hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling); 463 } while (pgd++, addr = next, addr != end); 464 } 465