arch/riscv/mm/hugetlbpage.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/hugetlb.h>
   3 #include <linux/err.h>
   4
   5 #ifdef CONFIG_RISCV_ISA_SVNAPOT
   6 pte_t huge_ptep_get(pte_t *ptep)
   7 {
   8         unsigned long pte_num;
   9         int i;
  10         pte_t orig_pte = ptep_get(ptep);
  11
  12         if (!pte_present(orig_pte) || !pte_napot(orig_pte))
  13                 return orig_pte;
  14
  15         pte_num = napot_pte_num(napot_cont_order(orig_pte));
  16
  17         for (i = 0; i < pte_num; i++, ptep++) {
  18                 pte_t pte = ptep_get(ptep);
  19
  20                 if (pte_dirty(pte))
  21                         orig_pte = pte_mkdirty(orig_pte);
  22
  23                 if (pte_young(pte))
  24                         orig_pte = pte_mkyoung(orig_pte);
  25         }
  26
  27         return orig_pte;
  28 }
  29
  30 pte_t *huge_pte_alloc(struct mm_struct *mm,
  31                       struct vm_area_struct *vma,
  32                       unsigned long addr,
  33                       unsigned long sz)
  34 {
  35         unsigned long order;
  36         pte_t *pte = NULL;
  37         pgd_t *pgd;
  38         p4d_t *p4d;
  39         pud_t *pud;
  40         pmd_t *pmd;
  41
  42         pgd = pgd_offset(mm, addr);
  43         p4d = p4d_alloc(mm, pgd, addr);
  44         if (!p4d)
  45                 return NULL;
  46
  47         pud = pud_alloc(mm, p4d, addr);
  48         if (!pud)
  49                 return NULL;
  50
  51         if (sz == PUD_SIZE) {
  52                 pte = (pte_t *)pud;
  53                 goto out;
  54         }
  55
  56         if (sz == PMD_SIZE) {
  57                 if (want_pmd_share(vma, addr) && pud_none(*pud))
  58                         pte = huge_pmd_share(mm, vma, addr, pud);
  59                 else
  60                         pte = (pte_t *)pmd_alloc(mm, pud, addr);
  61                 goto out;
  62         }
  63
  64         pmd = pmd_alloc(mm, pud, addr);
  65         if (!pmd)
  66                 return NULL;
  67
  68         for_each_napot_order(order) {
  69                 if (napot_cont_size(order) == sz) {
  70                         pte = pte_alloc_huge(mm, pmd, addr & napot_cont_mask(order));
  71                         break;
  72                 }
  73         }
  74
  75 out:
  76         if (pte) {
  77                 pte_t pteval = ptep_get_lockless(pte);
  78
  79                 WARN_ON_ONCE(pte_present(pteval) && !pte_huge(pteval));
  80         }
  81         return pte;
  82 }
  83
  84 pte_t *huge_pte_offset(struct mm_struct *mm,
  85                        unsigned long addr,
  86                        unsigned long sz)
  87 {
  88         unsigned long order;
  89         pte_t *pte = NULL;
  90         pgd_t *pgd;
  91         p4d_t *p4d;
  92         pud_t *pud;
  93         pmd_t *pmd;
  94
  95         pgd = pgd_offset(mm, addr);
  96         if (!pgd_present(*pgd))
  97                 return NULL;
  98
  99         p4d = p4d_offset(pgd, addr);
 100         if (!p4d_present(*p4d))
 101                 return NULL;
 102
 103         pud = pud_offset(p4d, addr);
 104         if (sz == PUD_SIZE)
 105                 /* must be pud huge, non-present or none */
 106                 return (pte_t *)pud;
 107
 108         if (!pud_present(*pud))
 109                 return NULL;
 110
 111         pmd = pmd_offset(pud, addr);
 112         if (sz == PMD_SIZE)
 113                 /* must be pmd huge, non-present or none */
 114                 return (pte_t *)pmd;
 115
 116         if (!pmd_present(*pmd))
 117                 return NULL;
 118
 119         for_each_napot_order(order) {
 120                 if (napot_cont_size(order) == sz) {
 121                         pte = pte_offset_huge(pmd, addr & napot_cont_mask(order));
 122                         break;
 123                 }
 124         }
 125         return pte;
 126 }
 127
 128 static pte_t get_clear_contig(struct mm_struct *mm,
 129                               unsigned long addr,
 130                               pte_t *ptep,
 131                               unsigned long pte_num)
 132 {
 133         pte_t orig_pte = ptep_get(ptep);
 134         unsigned long i;
 135
 136         for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) {
 137                 pte_t pte = ptep_get_and_clear(mm, addr, ptep);
 138
 139                 if (pte_dirty(pte))
 140                         orig_pte = pte_mkdirty(orig_pte);
 141
 142                 if (pte_young(pte))
 143                         orig_pte = pte_mkyoung(orig_pte);
 144         }
 145
 146         return orig_pte;
 147 }
 148
 149 static pte_t get_clear_contig_flush(struct mm_struct *mm,
 150                                     unsigned long addr,
 151                                     pte_t *ptep,
 152                                     unsigned long pte_num)
 153 {
 154         pte_t orig_pte = get_clear_contig(mm, addr, ptep, pte_num);
 155         struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
 156         bool valid = !pte_none(orig_pte);
 157
 158         if (valid)
 159                 flush_tlb_range(&vma, addr, addr + (PAGE_SIZE * pte_num));
 160
 161         return orig_pte;
 162 }
 163
 164 pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
 165 {
 166         unsigned long order;
 167
 168         for_each_napot_order(order) {
 169                 if (shift == napot_cont_shift(order)) {
 170                         entry = pte_mknapot(entry, order);
 171                         break;
 172                 }
 173         }
 174         if (order == NAPOT_ORDER_MAX)
 175                 entry = pte_mkhuge(entry);
 176
 177         return entry;
 178 }
 179
 180 void set_huge_pte_at(struct mm_struct *mm,
 181                      unsigned long addr,
 182                      pte_t *ptep,
 183                      pte_t pte,
 184                      unsigned long sz)
 185 {
 186         unsigned long hugepage_shift;
 187         int i, pte_num;
 188
 189         if (sz >= PGDIR_SIZE)
 190                 hugepage_shift = PGDIR_SHIFT;
 191         else if (sz >= P4D_SIZE)
 192                 hugepage_shift = P4D_SHIFT;
 193         else if (sz >= PUD_SIZE)
 194                 hugepage_shift = PUD_SHIFT;
 195         else if (sz >= PMD_SIZE)
 196                 hugepage_shift = PMD_SHIFT;
 197         else
 198                 hugepage_shift = PAGE_SHIFT;
 199
 200         pte_num = sz >> hugepage_shift;
 201         for (i = 0; i < pte_num; i++, ptep++, addr += (1 << hugepage_shift))
 202                 set_pte_at(mm, addr, ptep, pte);
 203 }
 204
 205 int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 206                                unsigned long addr,
 207                                pte_t *ptep,
 208                                pte_t pte,
 209                                int dirty)
 210 {
 211         struct mm_struct *mm = vma->vm_mm;
 212         unsigned long order;
 213         pte_t orig_pte;
 214         int i, pte_num;
 215
 216         if (!pte_napot(pte))
 217                 return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
 218
 219         order = napot_cont_order(pte);
 220         pte_num = napot_pte_num(order);
 221         ptep = huge_pte_offset(mm, addr, napot_cont_size(order));
 222         orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
 223
 224         if (pte_dirty(orig_pte))
 225                 pte = pte_mkdirty(pte);
 226
 227         if (pte_young(orig_pte))
 228                 pte = pte_mkyoung(pte);
 229
 230         for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
 231                 set_pte_at(mm, addr, ptep, pte);
 232
 233         return true;
 234 }
 235
 236 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 237                               unsigned long addr,
 238                               pte_t *ptep)
 239 {
 240         pte_t orig_pte = ptep_get(ptep);
 241         int pte_num;
 242
 243         if (!pte_napot(orig_pte))
 244                 return ptep_get_and_clear(mm, addr, ptep);
 245
 246         pte_num = napot_pte_num(napot_cont_order(orig_pte));
 247
 248         return get_clear_contig(mm, addr, ptep, pte_num);
 249 }
 250
 251 void huge_ptep_set_wrprotect(struct mm_struct *mm,
 252                              unsigned long addr,
 253                              pte_t *ptep)
 254 {
 255         pte_t pte = ptep_get(ptep);
 256         unsigned long order;
 257         pte_t orig_pte;
 258         int i, pte_num;
 259
 260         if (!pte_napot(pte)) {
 261                 ptep_set_wrprotect(mm, addr, ptep);
 262                 return;
 263         }
 264
 265         order = napot_cont_order(pte);
 266         pte_num = napot_pte_num(order);
 267         ptep = huge_pte_offset(mm, addr, napot_cont_size(order));
 268         orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
 269
 270         orig_pte = pte_wrprotect(orig_pte);
 271
 272         for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
 273                 set_pte_at(mm, addr, ptep, orig_pte);
 274 }
 275
 276 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 277                             unsigned long addr,
 278                             pte_t *ptep)
 279 {
 280         pte_t pte = ptep_get(ptep);
 281         int pte_num;
 282
 283         if (!pte_napot(pte))
 284                 return ptep_clear_flush(vma, addr, ptep);
 285
 286         pte_num = napot_pte_num(napot_cont_order(pte));
 287
 288         return get_clear_contig_flush(vma->vm_mm, addr, ptep, pte_num);
 289 }
 290
 291 void huge_pte_clear(struct mm_struct *mm,
 292                     unsigned long addr,
 293                     pte_t *ptep,
 294                     unsigned long sz)
 295 {
 296         pte_t pte = READ_ONCE(*ptep);
 297         int i, pte_num;
 298
 299         if (!pte_napot(pte)) {
 300                 pte_clear(mm, addr, ptep);
 301                 return;
 302         }
 303
 304         pte_num = napot_pte_num(napot_cont_order(pte));
 305         for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
 306                 pte_clear(mm, addr, ptep);
 307 }
 308
 309 static __init bool is_napot_size(unsigned long size)
 310 {
 311         unsigned long order;
 312
 313         if (!has_svnapot())
 314                 return false;
 315
 316         for_each_napot_order(order) {
 317                 if (size == napot_cont_size(order))
 318                         return true;
 319         }
 320         return false;
 321 }
 322
 323 static __init int napot_hugetlbpages_init(void)
 324 {
 325         if (has_svnapot()) {
 326                 unsigned long order;
 327
 328                 for_each_napot_order(order)
 329                         hugetlb_add_hstate(order);
 330         }
 331         return 0;
 332 }
 333 arch_initcall(napot_hugetlbpages_init);
 334
 335 #else
 336
 337 static __init bool is_napot_size(unsigned long size)
 338 {
 339         return false;
 340 }
 341
 342 #endif /*CONFIG_RISCV_ISA_SVNAPOT*/
 343
 344 int pud_huge(pud_t pud)
 345 {
 346         return pud_leaf(pud);
 347 }
 348
 349 int pmd_huge(pmd_t pmd)
 350 {
 351         return pmd_leaf(pmd);
 352 }
 353
 354 bool __init arch_hugetlb_valid_size(unsigned long size)
 355 {
 356         if (size == HPAGE_SIZE)
 357                 return true;
 358         else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)
 359                 return true;
 360         else if (is_napot_size(size))
 361                 return true;
 362         else
 363                 return false;
 364 }
 365
 366 #ifdef CONFIG_CONTIG_ALLOC
 367 static __init int gigantic_pages_init(void)
 368 {
 369         /* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
 370         if (IS_ENABLED(CONFIG_64BIT))
 371                 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
 372         return 0;
 373 }
 374 arch_initcall(gigantic_pages_init);
 375 #endif