arch/s390/mm/pgalloc.c

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This source file includes following definitions.
page_table_register_sysctl
crst_table_alloc
crst_table_free
__crst_table_upgrade
crst_table_upgrade
crst_table_downgrade
atomic_xor_bits
page_table_alloc_pgste
page_table_free_pgste
page_table_alloc
page_table_free
page_table_free_rcu
__tlb_remove_table
base_pgt_alloc
base_pgt_free
base_crst_alloc
base_crst_free
BASE_ADDR_END_FUNC
base_page_walk
base_segment_walk
base_region3_walk
base_region2_walk
base_region1_walk
base_asce_free
base_pgt_cache_init
base_asce_alloc
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Page table allocation functions
   4  *
   5  *    Copyright IBM Corp. 2016
   6  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  */
   8 
   9 #include <linux/sysctl.h>
  10 #include <linux/slab.h>
  11 #include <linux/mm.h>
  12 #include <asm/mmu_context.h>
  13 #include <asm/pgalloc.h>
  14 #include <asm/gmap.h>
  15 #include <asm/tlb.h>
  16 #include <asm/tlbflush.h>
  17 
  18 #ifdef CONFIG_PGSTE
  19 
  20 int page_table_allocate_pgste = 0;
  21 EXPORT_SYMBOL(page_table_allocate_pgste);
  22 
  23 static struct ctl_table page_table_sysctl[] = {
  24         {
  25                 .procname       = "allocate_pgste",
  26                 .data           = &page_table_allocate_pgste,
  27                 .maxlen         = sizeof(int),
  28                 .mode           = S_IRUGO | S_IWUSR,
  29                 .proc_handler   = proc_dointvec_minmax,
  30                 .extra1         = SYSCTL_ZERO,
  31                 .extra2         = SYSCTL_ONE,
  32         },
  33         { }
  34 };
  35 
  36 static struct ctl_table page_table_sysctl_dir[] = {
  37         {
  38                 .procname       = "vm",
  39                 .maxlen         = 0,
  40                 .mode           = 0555,
  41                 .child          = page_table_sysctl,
  42         },
  43         { }
  44 };
  45 
  46 static int __init page_table_register_sysctl(void)
  47 {
  48         return register_sysctl_table(page_table_sysctl_dir) ? 0 : -ENOMEM;
  49 }
  50 __initcall(page_table_register_sysctl);
  51 
  52 #endif /* CONFIG_PGSTE */
  53 
  54 unsigned long *crst_table_alloc(struct mm_struct *mm)
  55 {
  56         struct page *page = alloc_pages(GFP_KERNEL, 2);
  57 
  58         if (!page)
  59                 return NULL;
  60         arch_set_page_dat(page, 2);
  61         return (unsigned long *) page_to_phys(page);
  62 }
  63 
  64 void crst_table_free(struct mm_struct *mm, unsigned long *table)
  65 {
  66         free_pages((unsigned long) table, 2);
  67 }
  68 
  69 static void __crst_table_upgrade(void *arg)
  70 {
  71         struct mm_struct *mm = arg;
  72 
  73         /* we must change all active ASCEs to avoid the creation of new TLBs */
  74         if (current->active_mm == mm) {
  75                 S390_lowcore.user_asce = mm->context.asce;
  76                 if (current->thread.mm_segment == USER_DS) {
  77                         __ctl_load(S390_lowcore.user_asce, 1, 1);
  78                         /* Mark user-ASCE present in CR1 */
  79                         clear_cpu_flag(CIF_ASCE_PRIMARY);
  80                 }
  81                 if (current->thread.mm_segment == USER_DS_SACF) {
  82                         __ctl_load(S390_lowcore.user_asce, 7, 7);
  83                         /* enable_sacf_uaccess does all or nothing */
  84                         WARN_ON(!test_cpu_flag(CIF_ASCE_SECONDARY));
  85                 }
  86         }
  87         __tlb_flush_local();
  88 }
  89 
  90 int crst_table_upgrade(struct mm_struct *mm, unsigned long end)
  91 {
  92         unsigned long *table, *pgd;
  93         int rc, notify;
  94 
  95         /* upgrade should only happen from 3 to 4, 3 to 5, or 4 to 5 levels */
  96         VM_BUG_ON(mm->context.asce_limit < _REGION2_SIZE);
  97         rc = 0;
  98         notify = 0;
  99         while (mm->context.asce_limit < end) {
 100                 table = crst_table_alloc(mm);
 101                 if (!table) {
 102                         rc = -ENOMEM;
 103                         break;
 104                 }
 105                 spin_lock_bh(&mm->page_table_lock);
 106                 pgd = (unsigned long *) mm->pgd;
 107                 if (mm->context.asce_limit == _REGION2_SIZE) {
 108                         crst_table_init(table, _REGION2_ENTRY_EMPTY);
 109                         p4d_populate(mm, (p4d_t *) table, (pud_t *) pgd);
 110                         mm->pgd = (pgd_t *) table;
 111                         mm->context.asce_limit = _REGION1_SIZE;
 112                         mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
 113                                 _ASCE_USER_BITS | _ASCE_TYPE_REGION2;
 114                         mm_inc_nr_puds(mm);
 115                 } else {
 116                         crst_table_init(table, _REGION1_ENTRY_EMPTY);
 117                         pgd_populate(mm, (pgd_t *) table, (p4d_t *) pgd);
 118                         mm->pgd = (pgd_t *) table;
 119                         mm->context.asce_limit = -PAGE_SIZE;
 120                         mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
 121                                 _ASCE_USER_BITS | _ASCE_TYPE_REGION1;
 122                 }
 123                 notify = 1;
 124                 spin_unlock_bh(&mm->page_table_lock);
 125         }
 126         if (notify)
 127                 on_each_cpu(__crst_table_upgrade, mm, 0);
 128         return rc;
 129 }
 130 
 131 void crst_table_downgrade(struct mm_struct *mm)
 132 {
 133         pgd_t *pgd;
 134 
 135         /* downgrade should only happen from 3 to 2 levels (compat only) */
 136         VM_BUG_ON(mm->context.asce_limit != _REGION2_SIZE);
 137 
 138         if (current->active_mm == mm) {
 139                 clear_user_asce();
 140                 __tlb_flush_mm(mm);
 141         }
 142 
 143         pgd = mm->pgd;
 144         mm_dec_nr_pmds(mm);
 145         mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
 146         mm->context.asce_limit = _REGION3_SIZE;
 147         mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
 148                            _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT;
 149         crst_table_free(mm, (unsigned long *) pgd);
 150 
 151         if (current->active_mm == mm)
 152                 set_user_asce(mm);
 153 }
 154 
 155 static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
 156 {
 157         unsigned int old, new;
 158 
 159         do {
 160                 old = atomic_read(v);
 161                 new = old ^ bits;
 162         } while (atomic_cmpxchg(v, old, new) != old);
 163         return new;
 164 }
 165 
 166 #ifdef CONFIG_PGSTE
 167 
 168 struct page *page_table_alloc_pgste(struct mm_struct *mm)
 169 {
 170         struct page *page;
 171         u64 *table;
 172 
 173         page = alloc_page(GFP_KERNEL);
 174         if (page) {
 175                 table = (u64 *)page_to_phys(page);
 176                 memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
 177                 memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 178         }
 179         return page;
 180 }
 181 
 182 void page_table_free_pgste(struct page *page)
 183 {
 184         __free_page(page);
 185 }
 186 
 187 #endif /* CONFIG_PGSTE */
 188 
 189 /*
 190  * page table entry allocation/free routines.
 191  */
 192 unsigned long *page_table_alloc(struct mm_struct *mm)
 193 {
 194         unsigned long *table;
 195         struct page *page;
 196         unsigned int mask, bit;
 197 
 198         /* Try to get a fragment of a 4K page as a 2K page table */
 199         if (!mm_alloc_pgste(mm)) {
 200                 table = NULL;
 201                 spin_lock_bh(&mm->context.lock);
 202                 if (!list_empty(&mm->context.pgtable_list)) {
 203                         page = list_first_entry(&mm->context.pgtable_list,
 204                                                 struct page, lru);
 205                         mask = atomic_read(&page->_refcount) >> 24;
 206                         mask = (mask | (mask >> 4)) & 3;
 207                         if (mask != 3) {
 208                                 table = (unsigned long *) page_to_phys(page);
 209                                 bit = mask & 1;         /* =1 -> second 2K */
 210                                 if (bit)
 211                                         table += PTRS_PER_PTE;
 212                                 atomic_xor_bits(&page->_refcount,
 213                                                         1U << (bit + 24));
 214                                 list_del(&page->lru);
 215                         }
 216                 }
 217                 spin_unlock_bh(&mm->context.lock);
 218                 if (table)
 219                         return table;
 220         }
 221         /* Allocate a fresh page */
 222         page = alloc_page(GFP_KERNEL);
 223         if (!page)
 224                 return NULL;
 225         if (!pgtable_pte_page_ctor(page)) {
 226                 __free_page(page);
 227                 return NULL;
 228         }
 229         arch_set_page_dat(page, 0);
 230         /* Initialize page table */
 231         table = (unsigned long *) page_to_phys(page);
 232         if (mm_alloc_pgste(mm)) {
 233                 /* Return 4K page table with PGSTEs */
 234                 atomic_xor_bits(&page->_refcount, 3 << 24);
 235                 memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
 236                 memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 237         } else {
 238                 /* Return the first 2K fragment of the page */
 239                 atomic_xor_bits(&page->_refcount, 1 << 24);
 240                 memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
 241                 spin_lock_bh(&mm->context.lock);
 242                 list_add(&page->lru, &mm->context.pgtable_list);
 243                 spin_unlock_bh(&mm->context.lock);
 244         }
 245         return table;
 246 }
 247 
 248 void page_table_free(struct mm_struct *mm, unsigned long *table)
 249 {
 250         struct page *page;
 251         unsigned int bit, mask;
 252 
 253         page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 254         if (!mm_alloc_pgste(mm)) {
 255                 /* Free 2K page table fragment of a 4K page */
 256                 bit = (__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
 257                 spin_lock_bh(&mm->context.lock);
 258                 mask = atomic_xor_bits(&page->_refcount, 1U << (bit + 24));
 259                 mask >>= 24;
 260                 if (mask & 3)
 261                         list_add(&page->lru, &mm->context.pgtable_list);
 262                 else
 263                         list_del(&page->lru);
 264                 spin_unlock_bh(&mm->context.lock);
 265                 if (mask != 0)
 266                         return;
 267         } else {
 268                 atomic_xor_bits(&page->_refcount, 3U << 24);
 269         }
 270 
 271         pgtable_pte_page_dtor(page);
 272         __free_page(page);
 273 }
 274 
 275 void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 276                          unsigned long vmaddr)
 277 {
 278         struct mm_struct *mm;
 279         struct page *page;
 280         unsigned int bit, mask;
 281 
 282         mm = tlb->mm;
 283         page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 284         if (mm_alloc_pgste(mm)) {
 285                 gmap_unlink(mm, table, vmaddr);
 286                 table = (unsigned long *) (__pa(table) | 3);
 287                 tlb_remove_table(tlb, table);
 288                 return;
 289         }
 290         bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
 291         spin_lock_bh(&mm->context.lock);
 292         mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24));
 293         mask >>= 24;
 294         if (mask & 3)
 295                 list_add_tail(&page->lru, &mm->context.pgtable_list);
 296         else
 297                 list_del(&page->lru);
 298         spin_unlock_bh(&mm->context.lock);
 299         table = (unsigned long *) (__pa(table) | (1U << bit));
 300         tlb_remove_table(tlb, table);
 301 }
 302 
 303 void __tlb_remove_table(void *_table)
 304 {
 305         unsigned int mask = (unsigned long) _table & 3;
 306         void *table = (void *)((unsigned long) _table ^ mask);
 307         struct page *page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 308 
 309         switch (mask) {
 310         case 0:         /* pmd, pud, or p4d */
 311                 free_pages((unsigned long) table, 2);
 312                 break;
 313         case 1:         /* lower 2K of a 4K page table */
 314         case 2:         /* higher 2K of a 4K page table */
 315                 mask = atomic_xor_bits(&page->_refcount, mask << (4 + 24));
 316                 mask >>= 24;
 317                 if (mask != 0)
 318                         break;
 319                 /* fallthrough */
 320         case 3:         /* 4K page table with pgstes */
 321                 if (mask & 3)
 322                         atomic_xor_bits(&page->_refcount, 3 << 24);
 323                 pgtable_pte_page_dtor(page);
 324                 __free_page(page);
 325                 break;
 326         }
 327 }
 328 
 329 /*
 330  * Base infrastructure required to generate basic asces, region, segment,
 331  * and page tables that do not make use of enhanced features like EDAT1.
 332  */
 333 
 334 static struct kmem_cache *base_pgt_cache;
 335 
 336 static unsigned long base_pgt_alloc(void)
 337 {
 338         u64 *table;
 339 
 340         table = kmem_cache_alloc(base_pgt_cache, GFP_KERNEL);
 341         if (table)
 342                 memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
 343         return (unsigned long) table;
 344 }
 345 
 346 static void base_pgt_free(unsigned long table)
 347 {
 348         kmem_cache_free(base_pgt_cache, (void *) table);
 349 }
 350 
 351 static unsigned long base_crst_alloc(unsigned long val)
 352 {
 353         unsigned long table;
 354 
 355         table =  __get_free_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
 356         if (table)
 357                 crst_table_init((unsigned long *)table, val);
 358         return table;
 359 }
 360 
 361 static void base_crst_free(unsigned long table)
 362 {
 363         free_pages(table, CRST_ALLOC_ORDER);
 364 }
 365 
 366 #define BASE_ADDR_END_FUNC(NAME, SIZE)                                  \
 367 static inline unsigned long base_##NAME##_addr_end(unsigned long addr,  \
 368                                                    unsigned long end)   \
 369 {                                                                       \
 370         unsigned long next = (addr + (SIZE)) & ~((SIZE) - 1);           \
 371                                                                         \
 372         return (next - 1) < (end - 1) ? next : end;                     \
 373 }
 374 
 375 BASE_ADDR_END_FUNC(page,    _PAGE_SIZE)
 376 BASE_ADDR_END_FUNC(segment, _SEGMENT_SIZE)
 377 BASE_ADDR_END_FUNC(region3, _REGION3_SIZE)
 378 BASE_ADDR_END_FUNC(region2, _REGION2_SIZE)
 379 BASE_ADDR_END_FUNC(region1, _REGION1_SIZE)
 380 
 381 static inline unsigned long base_lra(unsigned long address)
 382 {
 383         unsigned long real;
 384 
 385         asm volatile(
 386                 "       lra     %0,0(%1)\n"
 387                 : "=d" (real) : "a" (address) : "cc");
 388         return real;
 389 }
 390 
 391 static int base_page_walk(unsigned long origin, unsigned long addr,
 392                           unsigned long end, int alloc)
 393 {
 394         unsigned long *pte, next;
 395 
 396         if (!alloc)
 397                 return 0;
 398         pte = (unsigned long *) origin;
 399         pte += (addr & _PAGE_INDEX) >> _PAGE_SHIFT;
 400         do {
 401                 next = base_page_addr_end(addr, end);
 402                 *pte = base_lra(addr);
 403         } while (pte++, addr = next, addr < end);
 404         return 0;
 405 }
 406 
 407 static int base_segment_walk(unsigned long origin, unsigned long addr,
 408                              unsigned long end, int alloc)
 409 {
 410         unsigned long *ste, next, table;
 411         int rc;
 412 
 413         ste = (unsigned long *) origin;
 414         ste += (addr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
 415         do {
 416                 next = base_segment_addr_end(addr, end);
 417                 if (*ste & _SEGMENT_ENTRY_INVALID) {
 418                         if (!alloc)
 419                                 continue;
 420                         table = base_pgt_alloc();
 421                         if (!table)
 422                                 return -ENOMEM;
 423                         *ste = table | _SEGMENT_ENTRY;
 424                 }
 425                 table = *ste & _SEGMENT_ENTRY_ORIGIN;
 426                 rc = base_page_walk(table, addr, next, alloc);
 427                 if (rc)
 428                         return rc;
 429                 if (!alloc)
 430                         base_pgt_free(table);
 431                 cond_resched();
 432         } while (ste++, addr = next, addr < end);
 433         return 0;
 434 }
 435 
 436 static int base_region3_walk(unsigned long origin, unsigned long addr,
 437                              unsigned long end, int alloc)
 438 {
 439         unsigned long *rtte, next, table;
 440         int rc;
 441 
 442         rtte = (unsigned long *) origin;
 443         rtte += (addr & _REGION3_INDEX) >> _REGION3_SHIFT;
 444         do {
 445                 next = base_region3_addr_end(addr, end);
 446                 if (*rtte & _REGION_ENTRY_INVALID) {
 447                         if (!alloc)
 448                                 continue;
 449                         table = base_crst_alloc(_SEGMENT_ENTRY_EMPTY);
 450                         if (!table)
 451                                 return -ENOMEM;
 452                         *rtte = table | _REGION3_ENTRY;
 453                 }
 454                 table = *rtte & _REGION_ENTRY_ORIGIN;
 455                 rc = base_segment_walk(table, addr, next, alloc);
 456                 if (rc)
 457                         return rc;
 458                 if (!alloc)
 459                         base_crst_free(table);
 460         } while (rtte++, addr = next, addr < end);
 461         return 0;
 462 }
 463 
 464 static int base_region2_walk(unsigned long origin, unsigned long addr,
 465                              unsigned long end, int alloc)
 466 {
 467         unsigned long *rste, next, table;
 468         int rc;
 469 
 470         rste = (unsigned long *) origin;
 471         rste += (addr & _REGION2_INDEX) >> _REGION2_SHIFT;
 472         do {
 473                 next = base_region2_addr_end(addr, end);
 474                 if (*rste & _REGION_ENTRY_INVALID) {
 475                         if (!alloc)
 476                                 continue;
 477                         table = base_crst_alloc(_REGION3_ENTRY_EMPTY);
 478                         if (!table)
 479                                 return -ENOMEM;
 480                         *rste = table | _REGION2_ENTRY;
 481                 }
 482                 table = *rste & _REGION_ENTRY_ORIGIN;
 483                 rc = base_region3_walk(table, addr, next, alloc);
 484                 if (rc)
 485                         return rc;
 486                 if (!alloc)
 487                         base_crst_free(table);
 488         } while (rste++, addr = next, addr < end);
 489         return 0;
 490 }
 491 
 492 static int base_region1_walk(unsigned long origin, unsigned long addr,
 493                              unsigned long end, int alloc)
 494 {
 495         unsigned long *rfte, next, table;
 496         int rc;
 497 
 498         rfte = (unsigned long *) origin;
 499         rfte += (addr & _REGION1_INDEX) >> _REGION1_SHIFT;
 500         do {
 501                 next = base_region1_addr_end(addr, end);
 502                 if (*rfte & _REGION_ENTRY_INVALID) {
 503                         if (!alloc)
 504                                 continue;
 505                         table = base_crst_alloc(_REGION2_ENTRY_EMPTY);
 506                         if (!table)
 507                                 return -ENOMEM;
 508                         *rfte = table | _REGION1_ENTRY;
 509                 }
 510                 table = *rfte & _REGION_ENTRY_ORIGIN;
 511                 rc = base_region2_walk(table, addr, next, alloc);
 512                 if (rc)
 513                         return rc;
 514                 if (!alloc)
 515                         base_crst_free(table);
 516         } while (rfte++, addr = next, addr < end);
 517         return 0;
 518 }
 519 
 520 /**
 521  * base_asce_free - free asce and tables returned from base_asce_alloc()
 522  * @asce: asce to be freed
 523  *
 524  * Frees all region, segment, and page tables that were allocated with a
 525  * corresponding base_asce_alloc() call.
 526  */
 527 void base_asce_free(unsigned long asce)
 528 {
 529         unsigned long table = asce & _ASCE_ORIGIN;
 530 
 531         if (!asce)
 532                 return;
 533         switch (asce & _ASCE_TYPE_MASK) {
 534         case _ASCE_TYPE_SEGMENT:
 535                 base_segment_walk(table, 0, _REGION3_SIZE, 0);
 536                 break;
 537         case _ASCE_TYPE_REGION3:
 538                 base_region3_walk(table, 0, _REGION2_SIZE, 0);
 539                 break;
 540         case _ASCE_TYPE_REGION2:
 541                 base_region2_walk(table, 0, _REGION1_SIZE, 0);
 542                 break;
 543         case _ASCE_TYPE_REGION1:
 544                 base_region1_walk(table, 0, -_PAGE_SIZE, 0);
 545                 break;
 546         }
 547         base_crst_free(table);
 548 }
 549 
 550 static int base_pgt_cache_init(void)
 551 {
 552         static DEFINE_MUTEX(base_pgt_cache_mutex);
 553         unsigned long sz = _PAGE_TABLE_SIZE;
 554 
 555         if (base_pgt_cache)
 556                 return 0;
 557         mutex_lock(&base_pgt_cache_mutex);
 558         if (!base_pgt_cache)
 559                 base_pgt_cache = kmem_cache_create("base_pgt", sz, sz, 0, NULL);
 560         mutex_unlock(&base_pgt_cache_mutex);
 561         return base_pgt_cache ? 0 : -ENOMEM;
 562 }
 563 
 564 /**
 565  * base_asce_alloc - create kernel mapping without enhanced DAT features
 566  * @addr: virtual start address of kernel mapping
 567  * @num_pages: number of consecutive pages
 568  *
 569  * Generate an asce, including all required region, segment and page tables,
 570  * that can be used to access the virtual kernel mapping. The difference is
 571  * that the returned asce does not make use of any enhanced DAT features like
 572  * e.g. large pages. This is required for some I/O functions that pass an
 573  * asce, like e.g. some service call requests.
 574  *
 575  * Note: the returned asce may NEVER be attached to any cpu. It may only be
 576  *       used for I/O requests. tlb entries that might result because the
 577  *       asce was attached to a cpu won't be cleared.
 578  */
 579 unsigned long base_asce_alloc(unsigned long addr, unsigned long num_pages)
 580 {
 581         unsigned long asce, table, end;
 582         int rc;
 583 
 584         if (base_pgt_cache_init())
 585                 return 0;
 586         end = addr + num_pages * PAGE_SIZE;
 587         if (end <= _REGION3_SIZE) {
 588                 table = base_crst_alloc(_SEGMENT_ENTRY_EMPTY);
 589                 if (!table)
 590                         return 0;
 591                 rc = base_segment_walk(table, addr, end, 1);
 592                 asce = table | _ASCE_TYPE_SEGMENT | _ASCE_TABLE_LENGTH;
 593         } else if (end <= _REGION2_SIZE) {
 594                 table = base_crst_alloc(_REGION3_ENTRY_EMPTY);
 595                 if (!table)
 596                         return 0;
 597                 rc = base_region3_walk(table, addr, end, 1);
 598                 asce = table | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 599         } else if (end <= _REGION1_SIZE) {
 600                 table = base_crst_alloc(_REGION2_ENTRY_EMPTY);
 601                 if (!table)
 602                         return 0;
 603                 rc = base_region2_walk(table, addr, end, 1);
 604                 asce = table | _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
 605         } else {
 606                 table = base_crst_alloc(_REGION1_ENTRY_EMPTY);
 607                 if (!table)
 608                         return 0;
 609                 rc = base_region1_walk(table, addr, end, 1);
 610                 asce = table | _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH;
 611         }
 612         if (rc) {
 613                 base_asce_free(asce);
 614                 asce = 0;
 615         }
 616         return asce;
 617 }
/* [<][>][^][v][top][bottom][index][help] */
root/arch/s390/mm/pgalloc.c

DEFINITIONS
