root/arch/s390/mm/gmap.c

DEFINITIONS

1. gmap_alloc
2. gmap_create
3. gmap_flush_tlb
4. gmap_radix_tree_free
5. gmap_rmap_radix_tree_free
6. gmap_free
7. gmap_get
8. gmap_put
9. gmap_remove
10. gmap_enable
11. gmap_disable
12. gmap_get_enabled
13. gmap_alloc_table
14. __gmap_segment_gaddr
15. __gmap_unlink_by_vmaddr
16. __gmap_unmap_by_gaddr
17. gmap_unmap_segment
18. gmap_map_segment
19. __gmap_translate
20. gmap_translate
21. gmap_unlink
22. __gmap_link
23. gmap_fault
24. __gmap_zap
25. gmap_discard
26. gmap_register_pte_notifier
27. gmap_unregister_pte_notifier
28. gmap_call_notifier
29. gmap_table_walk
30. gmap_pte_op_walk
31. gmap_pte_op_fixup
32. gmap_pte_op_end
33. gmap_pmd_op_walk
34. gmap_pmd_op_end
35. gmap_protect_pmd
36. gmap_protect_pte
37. gmap_protect_range
38. gmap_mprotect_notify
39. gmap_read_table
40. gmap_insert_rmap
41. gmap_protect_rmap
42. gmap_idte_one
43. gmap_unshadow_page
44. __gmap_unshadow_pgt
45. gmap_unshadow_pgt
46. __gmap_unshadow_sgt
47. gmap_unshadow_sgt
48. __gmap_unshadow_r3t
49. gmap_unshadow_r3t
50. __gmap_unshadow_r2t
51. gmap_unshadow_r2t
52. __gmap_unshadow_r1t
53. gmap_unshadow
54. gmap_find_shadow
55. gmap_shadow_valid
56. gmap_shadow
57. gmap_shadow_r2t
58. gmap_shadow_r3t
59. gmap_shadow_sgt
60. gmap_shadow_pgt_lookup
61. gmap_shadow_pgt
62. gmap_shadow_page
63. gmap_shadow_notify
64. ptep_notify
65. pmdp_notify_gmap
66. gmap_pmdp_xchg
67. gmap_pmdp_clear
68. gmap_pmdp_invalidate
69. gmap_pmdp_csp
70. gmap_pmdp_idte_local
71. gmap_pmdp_idte_global
72. gmap_test_and_clear_dirty_pmd
73. gmap_sync_dirty_log_pmd
74. thp_split_mm
75. __zap_zero_pages
76. s390_enable_sie
77. __s390_enable_skey_pte
78. __s390_enable_skey_hugetlb
79. s390_enable_skey
80. __s390_reset_cmma
81. s390_reset_cmma

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  KVM guest address space mapping code
   4  *
   5  *    Copyright IBM Corp. 2007, 2016, 2018
   6  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  *               David Hildenbrand <david@redhat.com>
   8  *               Janosch Frank <frankja@linux.vnet.ibm.com>
   9  */
  10 
  11 #include <linux/kernel.h>
  12 #include <linux/pagewalk.h>
  13 #include <linux/swap.h>
  14 #include <linux/smp.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/slab.h>
  17 #include <linux/swapops.h>
  18 #include <linux/ksm.h>
  19 #include <linux/mman.h>
  20 
  21 #include <asm/pgtable.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/gmap.h>
  24 #include <asm/tlb.h>
  25 
  26 #define GMAP_SHADOW_FAKE_TABLE 1ULL
  27 
  28 /**
  29  * gmap_alloc - allocate and initialize a guest address space
  30  * @mm: pointer to the parent mm_struct
  31  * @limit: maximum address of the gmap address space
  32  *
  33  * Returns a guest address space structure.
  34  */
  35 static struct gmap *gmap_alloc(unsigned long limit)
  36 {
  37         struct gmap *gmap;
  38         struct page *page;
  39         unsigned long *table;
  40         unsigned long etype, atype;
  41 
  42         if (limit < _REGION3_SIZE) {
  43                 limit = _REGION3_SIZE - 1;
  44                 atype = _ASCE_TYPE_SEGMENT;
  45                 etype = _SEGMENT_ENTRY_EMPTY;
  46         } else if (limit < _REGION2_SIZE) {
  47                 limit = _REGION2_SIZE - 1;
  48                 atype = _ASCE_TYPE_REGION3;
  49                 etype = _REGION3_ENTRY_EMPTY;
  50         } else if (limit < _REGION1_SIZE) {
  51                 limit = _REGION1_SIZE - 1;
  52                 atype = _ASCE_TYPE_REGION2;
  53                 etype = _REGION2_ENTRY_EMPTY;
  54         } else {
  55                 limit = -1UL;
  56                 atype = _ASCE_TYPE_REGION1;
  57                 etype = _REGION1_ENTRY_EMPTY;
  58         }
  59         gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
  60         if (!gmap)
  61                 goto out;
  62         INIT_LIST_HEAD(&gmap->crst_list);
  63         INIT_LIST_HEAD(&gmap->children);
  64         INIT_LIST_HEAD(&gmap->pt_list);
  65         INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
  66         INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
  67         INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC);
  68         spin_lock_init(&gmap->guest_table_lock);
  69         spin_lock_init(&gmap->shadow_lock);
  70         refcount_set(&gmap->ref_count, 1);
  71         page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
  72         if (!page)
  73                 goto out_free;
  74         page->index = 0;
  75         list_add(&page->lru, &gmap->crst_list);
  76         table = (unsigned long *) page_to_phys(page);
  77         crst_table_init(table, etype);
  78         gmap->table = table;
  79         gmap->asce = atype | _ASCE_TABLE_LENGTH |
  80                 _ASCE_USER_BITS | __pa(table);
  81         gmap->asce_end = limit;
  82         return gmap;
  83 
  84 out_free:
  85         kfree(gmap);
  86 out:
  87         return NULL;
  88 }
  89 
  90 /**
  91  * gmap_create - create a guest address space
  92  * @mm: pointer to the parent mm_struct
  93  * @limit: maximum size of the gmap address space
  94  *
  95  * Returns a guest address space structure.
  96  */
  97 struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
  98 {
  99         struct gmap *gmap;
 100         unsigned long gmap_asce;
 101 
 102         gmap = gmap_alloc(limit);
 103         if (!gmap)
 104                 return NULL;
 105         gmap->mm = mm;
 106         spin_lock(&mm->context.lock);
 107         list_add_rcu(&gmap->list, &mm->context.gmap_list);
 108         if (list_is_singular(&mm->context.gmap_list))
 109                 gmap_asce = gmap->asce;
 110         else
 111                 gmap_asce = -1UL;
 112         WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
 113         spin_unlock(&mm->context.lock);
 114         return gmap;
 115 }
 116 EXPORT_SYMBOL_GPL(gmap_create);
 117 
 118 static void gmap_flush_tlb(struct gmap *gmap)
 119 {
 120         if (MACHINE_HAS_IDTE)
 121                 __tlb_flush_idte(gmap->asce);
 122         else
 123                 __tlb_flush_global();
 124 }
 125 
 126 static void gmap_radix_tree_free(struct radix_tree_root *root)
 127 {
 128         struct radix_tree_iter iter;
 129         unsigned long indices[16];
 130         unsigned long index;
 131         void __rcu **slot;
 132         int i, nr;
 133 
 134         /* A radix tree is freed by deleting all of its entries */
 135         index = 0;
 136         do {
 137                 nr = 0;
 138                 radix_tree_for_each_slot(slot, root, &iter, index) {
 139                         indices[nr] = iter.index;
 140                         if (++nr == 16)
 141                                 break;
 142                 }
 143                 for (i = 0; i < nr; i++) {
 144                         index = indices[i];
 145                         radix_tree_delete(root, index);
 146                 }
 147         } while (nr > 0);
 148 }
 149 
 150 static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
 151 {
 152         struct gmap_rmap *rmap, *rnext, *head;
 153         struct radix_tree_iter iter;
 154         unsigned long indices[16];
 155         unsigned long index;
 156         void __rcu **slot;
 157         int i, nr;
 158 
 159         /* A radix tree is freed by deleting all of its entries */
 160         index = 0;
 161         do {
 162                 nr = 0;
 163                 radix_tree_for_each_slot(slot, root, &iter, index) {
 164                         indices[nr] = iter.index;
 165                         if (++nr == 16)
 166                                 break;
 167                 }
 168                 for (i = 0; i < nr; i++) {
 169                         index = indices[i];
 170                         head = radix_tree_delete(root, index);
 171                         gmap_for_each_rmap_safe(rmap, rnext, head)
 172                                 kfree(rmap);
 173                 }
 174         } while (nr > 0);
 175 }
 176 
 177 /**
 178  * gmap_free - free a guest address space
 179  * @gmap: pointer to the guest address space structure
 180  *
 181  * No locks required. There are no references to this gmap anymore.
 182  */
 183 static void gmap_free(struct gmap *gmap)
 184 {
 185         struct page *page, *next;
 186 
 187         /* Flush tlb of all gmaps (if not already done for shadows) */
 188         if (!(gmap_is_shadow(gmap) && gmap->removed))
 189                 gmap_flush_tlb(gmap);
 190         /* Free all segment & region tables. */
 191         list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
 192                 __free_pages(page, CRST_ALLOC_ORDER);
 193         gmap_radix_tree_free(&gmap->guest_to_host);
 194         gmap_radix_tree_free(&gmap->host_to_guest);
 195 
 196         /* Free additional data for a shadow gmap */
 197         if (gmap_is_shadow(gmap)) {
 198                 /* Free all page tables. */
 199                 list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
 200                         page_table_free_pgste(page);
 201                 gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
 202                 /* Release reference to the parent */
 203                 gmap_put(gmap->parent);
 204         }
 205 
 206         kfree(gmap);
 207 }
 208 
 209 /**
 210  * gmap_get - increase reference counter for guest address space
 211  * @gmap: pointer to the guest address space structure
 212  *
 213  * Returns the gmap pointer
 214  */
 215 struct gmap *gmap_get(struct gmap *gmap)
 216 {
 217         refcount_inc(&gmap->ref_count);
 218         return gmap;
 219 }
 220 EXPORT_SYMBOL_GPL(gmap_get);
 221 
 222 /**
 223  * gmap_put - decrease reference counter for guest address space
 224  * @gmap: pointer to the guest address space structure
 225  *
 226  * If the reference counter reaches zero the guest address space is freed.
 227  */
 228 void gmap_put(struct gmap *gmap)
 229 {
 230         if (refcount_dec_and_test(&gmap->ref_count))
 231                 gmap_free(gmap);
 232 }
 233 EXPORT_SYMBOL_GPL(gmap_put);
 234 
 235 /**
 236  * gmap_remove - remove a guest address space but do not free it yet
 237  * @gmap: pointer to the guest address space structure
 238  */
 239 void gmap_remove(struct gmap *gmap)
 240 {
 241         struct gmap *sg, *next;
 242         unsigned long gmap_asce;
 243 
 244         /* Remove all shadow gmaps linked to this gmap */
 245         if (!list_empty(&gmap->children)) {
 246                 spin_lock(&gmap->shadow_lock);
 247                 list_for_each_entry_safe(sg, next, &gmap->children, list) {
 248                         list_del(&sg->list);
 249                         gmap_put(sg);
 250                 }
 251                 spin_unlock(&gmap->shadow_lock);
 252         }
 253         /* Remove gmap from the pre-mm list */
 254         spin_lock(&gmap->mm->context.lock);
 255         list_del_rcu(&gmap->list);
 256         if (list_empty(&gmap->mm->context.gmap_list))
 257                 gmap_asce = 0;
 258         else if (list_is_singular(&gmap->mm->context.gmap_list))
 259                 gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
 260                                              struct gmap, list)->asce;
 261         else
 262                 gmap_asce = -1UL;
 263         WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
 264         spin_unlock(&gmap->mm->context.lock);
 265         synchronize_rcu();
 266         /* Put reference */
 267         gmap_put(gmap);
 268 }
 269 EXPORT_SYMBOL_GPL(gmap_remove);
 270 
 271 /**
 272  * gmap_enable - switch primary space to the guest address space
 273  * @gmap: pointer to the guest address space structure
 274  */
 275 void gmap_enable(struct gmap *gmap)
 276 {
 277         S390_lowcore.gmap = (unsigned long) gmap;
 278 }
 279 EXPORT_SYMBOL_GPL(gmap_enable);
 280 
 281 /**
 282  * gmap_disable - switch back to the standard primary address space
 283  * @gmap: pointer to the guest address space structure
 284  */
 285 void gmap_disable(struct gmap *gmap)
 286 {
 287         S390_lowcore.gmap = 0UL;
 288 }
 289 EXPORT_SYMBOL_GPL(gmap_disable);
 290 
 291 /**
 292  * gmap_get_enabled - get a pointer to the currently enabled gmap
 293  *
 294  * Returns a pointer to the currently enabled gmap. 0 if none is enabled.
 295  */
 296 struct gmap *gmap_get_enabled(void)
 297 {
 298         return (struct gmap *) S390_lowcore.gmap;
 299 }
 300 EXPORT_SYMBOL_GPL(gmap_get_enabled);
 301 
 302 /*
 303  * gmap_alloc_table is assumed to be called with mmap_sem held
 304  */
 305 static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
 306                             unsigned long init, unsigned long gaddr)
 307 {
 308         struct page *page;
 309         unsigned long *new;
 310 
 311         /* since we dont free the gmap table until gmap_free we can unlock */
 312         page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
 313         if (!page)
 314                 return -ENOMEM;
 315         new = (unsigned long *) page_to_phys(page);
 316         crst_table_init(new, init);
 317         spin_lock(&gmap->guest_table_lock);
 318         if (*table & _REGION_ENTRY_INVALID) {
 319                 list_add(&page->lru, &gmap->crst_list);
 320                 *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
 321                         (*table & _REGION_ENTRY_TYPE_MASK);
 322                 page->index = gaddr;
 323                 page = NULL;
 324         }
 325         spin_unlock(&gmap->guest_table_lock);
 326         if (page)
 327                 __free_pages(page, CRST_ALLOC_ORDER);
 328         return 0;
 329 }
 330 
 331 /**
 332  * __gmap_segment_gaddr - find virtual address from segment pointer
 333  * @entry: pointer to a segment table entry in the guest address space
 334  *
 335  * Returns the virtual address in the guest address space for the segment
 336  */
 337 static unsigned long __gmap_segment_gaddr(unsigned long *entry)
 338 {
 339         struct page *page;
 340         unsigned long offset, mask;
 341 
 342         offset = (unsigned long) entry / sizeof(unsigned long);
 343         offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
 344         mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
 345         page = virt_to_page((void *)((unsigned long) entry & mask));
 346         return page->index + offset;
 347 }
 348 
 349 /**
 350  * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
 351  * @gmap: pointer to the guest address space structure
 352  * @vmaddr: address in the host process address space
 353  *
 354  * Returns 1 if a TLB flush is required
 355  */
 356 static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
 357 {
 358         unsigned long *entry;
 359         int flush = 0;
 360 
 361         BUG_ON(gmap_is_shadow(gmap));
 362         spin_lock(&gmap->guest_table_lock);
 363         entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
 364         if (entry) {
 365                 flush = (*entry != _SEGMENT_ENTRY_EMPTY);
 366                 *entry = _SEGMENT_ENTRY_EMPTY;
 367         }
 368         spin_unlock(&gmap->guest_table_lock);
 369         return flush;
 370 }
 371 
 372 /**
 373  * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
 374  * @gmap: pointer to the guest address space structure
 375  * @gaddr: address in the guest address space
 376  *
 377  * Returns 1 if a TLB flush is required
 378  */
 379 static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
 380 {
 381         unsigned long vmaddr;
 382 
 383         vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
 384                                                    gaddr >> PMD_SHIFT);
 385         return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
 386 }
 387 
 388 /**
 389  * gmap_unmap_segment - unmap segment from the guest address space
 390  * @gmap: pointer to the guest address space structure
 391  * @to: address in the guest address space
 392  * @len: length of the memory area to unmap
 393  *
 394  * Returns 0 if the unmap succeeded, -EINVAL if not.
 395  */
 396 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
 397 {
 398         unsigned long off;
 399         int flush;
 400 
 401         BUG_ON(gmap_is_shadow(gmap));
 402         if ((to | len) & (PMD_SIZE - 1))
 403                 return -EINVAL;
 404         if (len == 0 || to + len < to)
 405                 return -EINVAL;
 406 
 407         flush = 0;
 408         down_write(&gmap->mm->mmap_sem);
 409         for (off = 0; off < len; off += PMD_SIZE)
 410                 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
 411         up_write(&gmap->mm->mmap_sem);
 412         if (flush)
 413                 gmap_flush_tlb(gmap);
 414         return 0;
 415 }
 416 EXPORT_SYMBOL_GPL(gmap_unmap_segment);
 417 
 418 /**
 419  * gmap_map_segment - map a segment to the guest address space
 420  * @gmap: pointer to the guest address space structure
 421  * @from: source address in the parent address space
 422  * @to: target address in the guest address space
 423  * @len: length of the memory area to map
 424  *
 425  * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
 426  */
 427 int gmap_map_segment(struct gmap *gmap, unsigned long from,
 428                      unsigned long to, unsigned long len)
 429 {
 430         unsigned long off;
 431         int flush;
 432 
 433         BUG_ON(gmap_is_shadow(gmap));
 434         if ((from | to | len) & (PMD_SIZE - 1))
 435                 return -EINVAL;
 436         if (len == 0 || from + len < from || to + len < to ||
 437             from + len - 1 > TASK_SIZE_MAX || to + len - 1 > gmap->asce_end)
 438                 return -EINVAL;
 439 
 440         flush = 0;
 441         down_write(&gmap->mm->mmap_sem);
 442         for (off = 0; off < len; off += PMD_SIZE) {
 443                 /* Remove old translation */
 444                 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
 445                 /* Store new translation */
 446                 if (radix_tree_insert(&gmap->guest_to_host,
 447                                       (to + off) >> PMD_SHIFT,
 448                                       (void *) from + off))
 449                         break;
 450         }
 451         up_write(&gmap->mm->mmap_sem);
 452         if (flush)
 453                 gmap_flush_tlb(gmap);
 454         if (off >= len)
 455                 return 0;
 456         gmap_unmap_segment(gmap, to, len);
 457         return -ENOMEM;
 458 }
 459 EXPORT_SYMBOL_GPL(gmap_map_segment);
 460 
 461 /**
 462  * __gmap_translate - translate a guest address to a user space address
 463  * @gmap: pointer to guest mapping meta data structure
 464  * @gaddr: guest address
 465  *
 466  * Returns user space address which corresponds to the guest address or
 467  * -EFAULT if no such mapping exists.
 468  * This function does not establish potentially missing page table entries.
 469  * The mmap_sem of the mm that belongs to the address space must be held
 470  * when this function gets called.
 471  *
 472  * Note: Can also be called for shadow gmaps.
 473  */
 474 unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
 475 {
 476         unsigned long vmaddr;
 477 
 478         vmaddr = (unsigned long)
 479                 radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
 480         /* Note: guest_to_host is empty for a shadow gmap */
 481         return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
 482 }
 483 EXPORT_SYMBOL_GPL(__gmap_translate);
 484 
 485 /**
 486  * gmap_translate - translate a guest address to a user space address
 487  * @gmap: pointer to guest mapping meta data structure
 488  * @gaddr: guest address
 489  *
 490  * Returns user space address which corresponds to the guest address or
 491  * -EFAULT if no such mapping exists.
 492  * This function does not establish potentially missing page table entries.
 493  */
 494 unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
 495 {
 496         unsigned long rc;
 497 
 498         down_read(&gmap->mm->mmap_sem);
 499         rc = __gmap_translate(gmap, gaddr);
 500         up_read(&gmap->mm->mmap_sem);
 501         return rc;
 502 }
 503 EXPORT_SYMBOL_GPL(gmap_translate);
 504 
 505 /**
 506  * gmap_unlink - disconnect a page table from the gmap shadow tables
 507  * @gmap: pointer to guest mapping meta data structure
 508  * @table: pointer to the host page table
 509  * @vmaddr: vm address associated with the host page table
 510  */
 511 void gmap_unlink(struct mm_struct *mm, unsigned long *table,
 512                  unsigned long vmaddr)
 513 {
 514         struct gmap *gmap;
 515         int flush;
 516 
 517         rcu_read_lock();
 518         list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
 519                 flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
 520                 if (flush)
 521                         gmap_flush_tlb(gmap);
 522         }
 523         rcu_read_unlock();
 524 }
 525 
 526 static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *old, pmd_t new,
 527                            unsigned long gaddr);
 528 
 529 /**
 530  * gmap_link - set up shadow page tables to connect a host to a guest address
 531  * @gmap: pointer to guest mapping meta data structure
 532  * @gaddr: guest address
 533  * @vmaddr: vm address
 534  *
 535  * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
 536  * if the vm address is already mapped to a different guest segment.
 537  * The mmap_sem of the mm that belongs to the address space must be held
 538  * when this function gets called.
 539  */
 540 int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
 541 {
 542         struct mm_struct *mm;
 543         unsigned long *table;
 544         spinlock_t *ptl;
 545         pgd_t *pgd;
 546         p4d_t *p4d;
 547         pud_t *pud;
 548         pmd_t *pmd;
 549         u64 unprot;
 550         int rc;
 551 
 552         BUG_ON(gmap_is_shadow(gmap));
 553         /* Create higher level tables in the gmap page table */
 554         table = gmap->table;
 555         if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
 556                 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
 557                 if ((*table & _REGION_ENTRY_INVALID) &&
 558                     gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
 559                                      gaddr & _REGION1_MASK))
 560                         return -ENOMEM;
 561                 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 562         }
 563         if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
 564                 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
 565                 if ((*table & _REGION_ENTRY_INVALID) &&
 566                     gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
 567                                      gaddr & _REGION2_MASK))
 568                         return -ENOMEM;
 569                 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 570         }
 571         if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
 572                 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
 573                 if ((*table & _REGION_ENTRY_INVALID) &&
 574                     gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
 575                                      gaddr & _REGION3_MASK))
 576                         return -ENOMEM;
 577                 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 578         }
 579         table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
 580         /* Walk the parent mm page table */
 581         mm = gmap->mm;
 582         pgd = pgd_offset(mm, vmaddr);
 583         VM_BUG_ON(pgd_none(*pgd));
 584         p4d = p4d_offset(pgd, vmaddr);
 585         VM_BUG_ON(p4d_none(*p4d));
 586         pud = pud_offset(p4d, vmaddr);
 587         VM_BUG_ON(pud_none(*pud));
 588         /* large puds cannot yet be handled */
 589         if (pud_large(*pud))
 590                 return -EFAULT;
 591         pmd = pmd_offset(pud, vmaddr);
 592         VM_BUG_ON(pmd_none(*pmd));
 593         /* Are we allowed to use huge pages? */
 594         if (pmd_large(*pmd) && !gmap->mm->context.allow_gmap_hpage_1m)
 595                 return -EFAULT;
 596         /* Link gmap segment table entry location to page table. */
 597         rc = radix_tree_preload(GFP_KERNEL);
 598         if (rc)
 599                 return rc;
 600         ptl = pmd_lock(mm, pmd);
 601         spin_lock(&gmap->guest_table_lock);
 602         if (*table == _SEGMENT_ENTRY_EMPTY) {
 603                 rc = radix_tree_insert(&gmap->host_to_guest,
 604                                        vmaddr >> PMD_SHIFT, table);
 605                 if (!rc) {
 606                         if (pmd_large(*pmd)) {
 607                                 *table = (pmd_val(*pmd) &
 608                                           _SEGMENT_ENTRY_HARDWARE_BITS_LARGE)
 609                                         | _SEGMENT_ENTRY_GMAP_UC;
 610                         } else
 611                                 *table = pmd_val(*pmd) &
 612                                         _SEGMENT_ENTRY_HARDWARE_BITS;
 613                 }
 614         } else if (*table & _SEGMENT_ENTRY_PROTECT &&
 615                    !(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) {
 616                 unprot = (u64)*table;
 617                 unprot &= ~_SEGMENT_ENTRY_PROTECT;
 618                 unprot |= _SEGMENT_ENTRY_GMAP_UC;
 619                 gmap_pmdp_xchg(gmap, (pmd_t *)table, __pmd(unprot), gaddr);
 620         }
 621         spin_unlock(&gmap->guest_table_lock);
 622         spin_unlock(ptl);
 623         radix_tree_preload_end();
 624         return rc;
 625 }
 626 
 627 /**
 628  * gmap_fault - resolve a fault on a guest address
 629  * @gmap: pointer to guest mapping meta data structure
 630  * @gaddr: guest address
 631  * @fault_flags: flags to pass down to handle_mm_fault()
 632  *
 633  * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
 634  * if the vm address is already mapped to a different guest segment.
 635  */
 636 int gmap_fault(struct gmap *gmap, unsigned long gaddr,
 637                unsigned int fault_flags)
 638 {
 639         unsigned long vmaddr;
 640         int rc;
 641         bool unlocked;
 642 
 643         down_read(&gmap->mm->mmap_sem);
 644 
 645 retry:
 646         unlocked = false;
 647         vmaddr = __gmap_translate(gmap, gaddr);
 648         if (IS_ERR_VALUE(vmaddr)) {
 649                 rc = vmaddr;
 650                 goto out_up;
 651         }
 652         if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
 653                              &unlocked)) {
 654                 rc = -EFAULT;
 655                 goto out_up;
 656         }
 657         /*
 658          * In the case that fixup_user_fault unlocked the mmap_sem during
 659          * faultin redo __gmap_translate to not race with a map/unmap_segment.
 660          */
 661         if (unlocked)
 662                 goto retry;
 663 
 664         rc = __gmap_link(gmap, gaddr, vmaddr);
 665 out_up:
 666         up_read(&gmap->mm->mmap_sem);
 667         return rc;
 668 }
 669 EXPORT_SYMBOL_GPL(gmap_fault);
 670 
 671 /*
 672  * this function is assumed to be called with mmap_sem held
 673  */
 674 void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
 675 {
 676         unsigned long vmaddr;
 677         spinlock_t *ptl;
 678         pte_t *ptep;
 679 
 680         /* Find the vm address for the guest address */
 681         vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
 682                                                    gaddr >> PMD_SHIFT);
 683         if (vmaddr) {
 684                 vmaddr |= gaddr & ~PMD_MASK;
 685                 /* Get pointer to the page table entry */
 686                 ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
 687                 if (likely(ptep))
 688                         ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
 689                 pte_unmap_unlock(ptep, ptl);
 690         }
 691 }
 692 EXPORT_SYMBOL_GPL(__gmap_zap);
 693 
 694 void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
 695 {
 696         unsigned long gaddr, vmaddr, size;
 697         struct vm_area_struct *vma;
 698 
 699         down_read(&gmap->mm->mmap_sem);
 700         for (gaddr = from; gaddr < to;
 701              gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
 702                 /* Find the vm address for the guest address */
 703                 vmaddr = (unsigned long)
 704                         radix_tree_lookup(&gmap->guest_to_host,
 705                                           gaddr >> PMD_SHIFT);
 706                 if (!vmaddr)
 707                         continue;
 708                 vmaddr |= gaddr & ~PMD_MASK;
 709                 /* Find vma in the parent mm */
 710                 vma = find_vma(gmap->mm, vmaddr);
 711                 if (!vma)
 712                         continue;
 713                 /*
 714                  * We do not discard pages that are backed by
 715                  * hugetlbfs, so we don't have to refault them.
 716                  */
 717                 if (is_vm_hugetlb_page(vma))
 718                         continue;
 719                 size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
 720                 zap_page_range(vma, vmaddr, size);
 721         }
 722         up_read(&gmap->mm->mmap_sem);
 723 }
 724 EXPORT_SYMBOL_GPL(gmap_discard);
 725 
 726 static LIST_HEAD(gmap_notifier_list);
 727 static DEFINE_SPINLOCK(gmap_notifier_lock);
 728 
 729 /**
 730  * gmap_register_pte_notifier - register a pte invalidation callback
 731  * @nb: pointer to the gmap notifier block
 732  */
 733 void gmap_register_pte_notifier(struct gmap_notifier *nb)
 734 {
 735         spin_lock(&gmap_notifier_lock);
 736         list_add_rcu(&nb->list, &gmap_notifier_list);
 737         spin_unlock(&gmap_notifier_lock);
 738 }
 739 EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
 740 
 741 /**
 742  * gmap_unregister_pte_notifier - remove a pte invalidation callback
 743  * @nb: pointer to the gmap notifier block
 744  */
 745 void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
 746 {
 747         spin_lock(&gmap_notifier_lock);
 748         list_del_rcu(&nb->list);
 749         spin_unlock(&gmap_notifier_lock);
 750         synchronize_rcu();
 751 }
 752 EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
 753 
 754 /**
 755  * gmap_call_notifier - call all registered invalidation callbacks
 756  * @gmap: pointer to guest mapping meta data structure
 757  * @start: start virtual address in the guest address space
 758  * @end: end virtual address in the guest address space
 759  */
 760 static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
 761                                unsigned long end)
 762 {
 763         struct gmap_notifier *nb;
 764 
 765         list_for_each_entry(nb, &gmap_notifier_list, list)
 766                 nb->notifier_call(gmap, start, end);
 767 }
 768 
 769 /**
 770  * gmap_table_walk - walk the gmap page tables
 771  * @gmap: pointer to guest mapping meta data structure
 772  * @gaddr: virtual address in the guest address space
 773  * @level: page table level to stop at
 774  *
 775  * Returns a table entry pointer for the given guest address and @level
 776  * @level=0 : returns a pointer to a page table table entry (or NULL)
 777  * @level=1 : returns a pointer to a segment table entry (or NULL)
 778  * @level=2 : returns a pointer to a region-3 table entry (or NULL)
 779  * @level=3 : returns a pointer to a region-2 table entry (or NULL)
 780  * @level=4 : returns a pointer to a region-1 table entry (or NULL)
 781  *
 782  * Returns NULL if the gmap page tables could not be walked to the
 783  * requested level.
 784  *
 785  * Note: Can also be called for shadow gmaps.
 786  */
 787 static inline unsigned long *gmap_table_walk(struct gmap *gmap,
 788                                              unsigned long gaddr, int level)
 789 {
 790         const int asce_type = gmap->asce & _ASCE_TYPE_MASK;
 791         unsigned long *table;
 792 
 793         if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
 794                 return NULL;
 795         if (gmap_is_shadow(gmap) && gmap->removed)
 796                 return NULL;
 797 
 798         if (asce_type != _ASCE_TYPE_REGION1 &&
 799             gaddr & (-1UL << (31 + (asce_type >> 2) * 11)))
 800                 return NULL;
 801 
 802         table = gmap->table;
 803         switch (gmap->asce & _ASCE_TYPE_MASK) {
 804         case _ASCE_TYPE_REGION1:
 805                 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
 806                 if (level == 4)
 807                         break;
 808                 if (*table & _REGION_ENTRY_INVALID)
 809                         return NULL;
 810                 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 811                 /* Fallthrough */
 812         case _ASCE_TYPE_REGION2:
 813                 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
 814                 if (level == 3)
 815                         break;
 816                 if (*table & _REGION_ENTRY_INVALID)
 817                         return NULL;
 818                 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 819                 /* Fallthrough */
 820         case _ASCE_TYPE_REGION3:
 821                 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
 822                 if (level == 2)
 823                         break;
 824                 if (*table & _REGION_ENTRY_INVALID)
 825                         return NULL;
 826                 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 827                 /* Fallthrough */
 828         case _ASCE_TYPE_SEGMENT:
 829                 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
 830                 if (level == 1)
 831                         break;
 832                 if (*table & _REGION_ENTRY_INVALID)
 833                         return NULL;
 834                 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
 835                 table += (gaddr & _PAGE_INDEX) >> _PAGE_SHIFT;
 836         }
 837         return table;
 838 }
 839 
 840 /**
 841  * gmap_pte_op_walk - walk the gmap page table, get the page table lock
 842  *                    and return the pte pointer
 843  * @gmap: pointer to guest mapping meta data structure
 844  * @gaddr: virtual address in the guest address space
 845  * @ptl: pointer to the spinlock pointer
 846  *
 847  * Returns a pointer to the locked pte for a guest address, or NULL
 848  */
 849 static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
 850                                spinlock_t **ptl)
 851 {
 852         unsigned long *table;
 853 
 854         BUG_ON(gmap_is_shadow(gmap));
 855         /* Walk the gmap page table, lock and get pte pointer */
 856         table = gmap_table_walk(gmap, gaddr, 1); /* get segment pointer */
 857         if (!table || *table & _SEGMENT_ENTRY_INVALID)
 858                 return NULL;
 859         return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
 860 }
 861 
 862 /**
 863  * gmap_pte_op_fixup - force a page in and connect the gmap page table
 864  * @gmap: pointer to guest mapping meta data structure
 865  * @gaddr: virtual address in the guest address space
 866  * @vmaddr: address in the host process address space
 867  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
 868  *
 869  * Returns 0 if the caller can retry __gmap_translate (might fail again),
 870  * -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
 871  * up or connecting the gmap page table.
 872  */
 873 static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
 874                              unsigned long vmaddr, int prot)
 875 {
 876         struct mm_struct *mm = gmap->mm;
 877         unsigned int fault_flags;
 878         bool unlocked = false;
 879 
 880         BUG_ON(gmap_is_shadow(gmap));
 881         fault_flags = (prot == PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
 882         if (fixup_user_fault(current, mm, vmaddr, fault_flags, &unlocked))
 883                 return -EFAULT;
 884         if (unlocked)
 885                 /* lost mmap_sem, caller has to retry __gmap_translate */
 886                 return 0;
 887         /* Connect the page tables */
 888         return __gmap_link(gmap, gaddr, vmaddr);
 889 }
 890 
 891 /**
 892  * gmap_pte_op_end - release the page table lock
 893  * @ptl: pointer to the spinlock pointer
 894  */
 895 static void gmap_pte_op_end(spinlock_t *ptl)
 896 {
 897         if (ptl)
 898                 spin_unlock(ptl);
 899 }
 900 
 901 /**
 902  * gmap_pmd_op_walk - walk the gmap tables, get the guest table lock
 903  *                    and return the pmd pointer
 904  * @gmap: pointer to guest mapping meta data structure
 905  * @gaddr: virtual address in the guest address space
 906  *
 907  * Returns a pointer to the pmd for a guest address, or NULL
 908  */
 909 static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr)
 910 {
 911         pmd_t *pmdp;
 912 
 913         BUG_ON(gmap_is_shadow(gmap));
 914         pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1);
 915         if (!pmdp)
 916                 return NULL;
 917 
 918         /* without huge pages, there is no need to take the table lock */
 919         if (!gmap->mm->context.allow_gmap_hpage_1m)
 920                 return pmd_none(*pmdp) ? NULL : pmdp;
 921 
 922         spin_lock(&gmap->guest_table_lock);
 923         if (pmd_none(*pmdp)) {
 924                 spin_unlock(&gmap->guest_table_lock);
 925                 return NULL;
 926         }
 927 
 928         /* 4k page table entries are locked via the pte (pte_alloc_map_lock). */
 929         if (!pmd_large(*pmdp))
 930                 spin_unlock(&gmap->guest_table_lock);
 931         return pmdp;
 932 }
 933 
 934 /**
 935  * gmap_pmd_op_end - release the guest_table_lock if needed
 936  * @gmap: pointer to the guest mapping meta data structure
 937  * @pmdp: pointer to the pmd
 938  */
 939 static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
 940 {
 941         if (pmd_large(*pmdp))
 942                 spin_unlock(&gmap->guest_table_lock);
 943 }
 944 
 945 /*
 946  * gmap_protect_pmd - remove access rights to memory and set pmd notification bits
 947  * @pmdp: pointer to the pmd to be protected
 948  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
 949  * @bits: notification bits to set
 950  *
 951  * Returns:
 952  * 0 if successfully protected
 953  * -EAGAIN if a fixup is needed
 954  * -EINVAL if unsupported notifier bits have been specified
 955  *
 956  * Expected to be called with sg->mm->mmap_sem in read and
 957  * guest_table_lock held.
 958  */
 959 static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr,
 960                             pmd_t *pmdp, int prot, unsigned long bits)
 961 {
 962         int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID;
 963         int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT;
 964         pmd_t new = *pmdp;
 965 
 966         /* Fixup needed */
 967         if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE)))
 968                 return -EAGAIN;
 969 
 970         if (prot == PROT_NONE && !pmd_i) {
 971                 pmd_val(new) |= _SEGMENT_ENTRY_INVALID;
 972                 gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
 973         }
 974 
 975         if (prot == PROT_READ && !pmd_p) {
 976                 pmd_val(new) &= ~_SEGMENT_ENTRY_INVALID;
 977                 pmd_val(new) |= _SEGMENT_ENTRY_PROTECT;
 978                 gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
 979         }
 980 
 981         if (bits & GMAP_NOTIFY_MPROT)
 982                 pmd_val(*pmdp) |= _SEGMENT_ENTRY_GMAP_IN;
 983 
 984         /* Shadow GMAP protection needs split PMDs */
 985         if (bits & GMAP_NOTIFY_SHADOW)
 986                 return -EINVAL;
 987 
 988         return 0;
 989 }
 990 
 991 /*
 992  * gmap_protect_pte - remove access rights to memory and set pgste bits
 993  * @gmap: pointer to guest mapping meta data structure
 994  * @gaddr: virtual address in the guest address space
 995  * @pmdp: pointer to the pmd associated with the pte
 996  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
 997  * @bits: notification bits to set
 998  *
 999  * Returns 0 if successfully protected, -ENOMEM if out of memory and
1000  * -EAGAIN if a fixup is needed.
1001  *
1002  * Expected to be called with sg->mm->mmap_sem in read
1003  */
1004 static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
1005                             pmd_t *pmdp, int prot, unsigned long bits)
1006 {
1007         int rc;
1008         pte_t *ptep;
1009         spinlock_t *ptl = NULL;
1010         unsigned long pbits = 0;
1011 
1012         if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
1013                 return -EAGAIN;
1014 
1015         ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl);
1016         if (!ptep)
1017                 return -ENOMEM;
1018 
1019         pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;
1020         pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;
1021         /* Protect and unlock. */
1022         rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);
1023         gmap_pte_op_end(ptl);
1024         return rc;
1025 }
1026 
1027 /*
1028  * gmap_protect_range - remove access rights to memory and set pgste bits
1029  * @gmap: pointer to guest mapping meta data structure
1030  * @gaddr: virtual address in the guest address space
1031  * @len: size of area
1032  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1033  * @bits: pgste notification bits to set
1034  *
1035  * Returns 0 if successfully protected, -ENOMEM if out of memory and
1036  * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
1037  *
1038  * Called with sg->mm->mmap_sem in read.
1039  */
1040 static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
1041                               unsigned long len, int prot, unsigned long bits)
1042 {
1043         unsigned long vmaddr, dist;
1044         pmd_t *pmdp;
1045         int rc;
1046 
1047         BUG_ON(gmap_is_shadow(gmap));
1048         while (len) {
1049                 rc = -EAGAIN;
1050                 pmdp = gmap_pmd_op_walk(gmap, gaddr);
1051                 if (pmdp) {
1052                         if (!pmd_large(*pmdp)) {
1053                                 rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
1054                                                       bits);
1055                                 if (!rc) {
1056                                         len -= PAGE_SIZE;
1057                                         gaddr += PAGE_SIZE;
1058                                 }
1059                         } else {
1060                                 rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
1061                                                       bits);
1062                                 if (!rc) {
1063                                         dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
1064                                         len = len < dist ? 0 : len - dist;
1065                                         gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
1066                                 }
1067                         }
1068                         gmap_pmd_op_end(gmap, pmdp);
1069                 }
1070                 if (rc) {
1071                         if (rc == -EINVAL)
1072                                 return rc;
1073 
1074                         /* -EAGAIN, fixup of userspace mm and gmap */
1075                         vmaddr = __gmap_translate(gmap, gaddr);
1076                         if (IS_ERR_VALUE(vmaddr))
1077                                 return vmaddr;
1078                         rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
1079                         if (rc)
1080                                 return rc;
1081                 }
1082         }
1083         return 0;
1084 }
1085 
1086 /**
1087  * gmap_mprotect_notify - change access rights for a range of ptes and
1088  *                        call the notifier if any pte changes again
1089  * @gmap: pointer to guest mapping meta data structure
1090  * @gaddr: virtual address in the guest address space
1091  * @len: size of area
1092  * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1093  *
1094  * Returns 0 if for each page in the given range a gmap mapping exists,
1095  * the new access rights could be set and the notifier could be armed.
1096  * If the gmap mapping is missing for one or more pages -EFAULT is
1097  * returned. If no memory could be allocated -ENOMEM is returned.
1098  * This function establishes missing page table entries.
1099  */
1100 int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
1101                          unsigned long len, int prot)
1102 {
1103         int rc;
1104 
1105         if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
1106                 return -EINVAL;
1107         if (!MACHINE_HAS_ESOP && prot == PROT_READ)
1108                 return -EINVAL;
1109         down_read(&gmap->mm->mmap_sem);
1110         rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
1111         up_read(&gmap->mm->mmap_sem);
1112         return rc;
1113 }
1114 EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
1115 
1116 /**
1117  * gmap_read_table - get an unsigned long value from a guest page table using
1118  *                   absolute addressing, without marking the page referenced.
1119  * @gmap: pointer to guest mapping meta data structure
1120  * @gaddr: virtual address in the guest address space
1121  * @val: pointer to the unsigned long value to return
1122  *
1123  * Returns 0 if the value was read, -ENOMEM if out of memory and -EFAULT
1124  * if reading using the virtual address failed. -EINVAL if called on a gmap
1125  * shadow.
1126  *
1127  * Called with gmap->mm->mmap_sem in read.
1128  */
1129 int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val)
1130 {
1131         unsigned long address, vmaddr;
1132         spinlock_t *ptl;
1133         pte_t *ptep, pte;
1134         int rc;
1135 
1136         if (gmap_is_shadow(gmap))
1137                 return -EINVAL;
1138 
1139         while (1) {
1140                 rc = -EAGAIN;
1141                 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
1142                 if (ptep) {
1143                         pte = *ptep;
1144                         if (pte_present(pte) && (pte_val(pte) & _PAGE_READ)) {
1145                                 address = pte_val(pte) & PAGE_MASK;
1146                                 address += gaddr & ~PAGE_MASK;
1147                                 *val = *(unsigned long *) address;
1148                                 pte_val(*ptep) |= _PAGE_YOUNG;
1149                                 /* Do *NOT* clear the _PAGE_INVALID bit! */
1150                                 rc = 0;
1151                         }
1152                         gmap_pte_op_end(ptl);
1153                 }
1154                 if (!rc)
1155                         break;
1156                 vmaddr = __gmap_translate(gmap, gaddr);
1157                 if (IS_ERR_VALUE(vmaddr)) {
1158                         rc = vmaddr;
1159                         break;
1160                 }
1161                 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, PROT_READ);
1162                 if (rc)
1163                         break;
1164         }
1165         return rc;
1166 }
1167 EXPORT_SYMBOL_GPL(gmap_read_table);
1168 
1169 /**
1170  * gmap_insert_rmap - add a rmap to the host_to_rmap radix tree
1171  * @sg: pointer to the shadow guest address space structure
1172  * @vmaddr: vm address associated with the rmap
1173  * @rmap: pointer to the rmap structure
1174  *
1175  * Called with the sg->guest_table_lock
1176  */
1177 static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
1178                                     struct gmap_rmap *rmap)
1179 {
1180         void __rcu **slot;
1181 
1182         BUG_ON(!gmap_is_shadow(sg));
1183         slot = radix_tree_lookup_slot(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
1184         if (slot) {
1185                 rmap->next = radix_tree_deref_slot_protected(slot,
1186                                                         &sg->guest_table_lock);
1187                 radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
1188         } else {
1189                 rmap->next = NULL;
1190                 radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT,
1191                                   rmap);
1192         }
1193 }
1194 
1195 /**
1196  * gmap_protect_rmap - restrict access rights to memory (RO) and create an rmap
1197  * @sg: pointer to the shadow guest address space structure
1198  * @raddr: rmap address in the shadow gmap
1199  * @paddr: address in the parent guest address space
1200  * @len: length of the memory area to protect
1201  *
1202  * Returns 0 if successfully protected and the rmap was created, -ENOMEM
1203  * if out of memory and -EFAULT if paddr is invalid.
1204  */
1205 static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr,
1206                              unsigned long paddr, unsigned long len)
1207 {
1208         struct gmap *parent;
1209         struct gmap_rmap *rmap;
1210         unsigned long vmaddr;
1211         spinlock_t *ptl;
1212         pte_t *ptep;
1213         int rc;
1214 
1215         BUG_ON(!gmap_is_shadow(sg));
1216         parent = sg->parent;
1217         while (len) {
1218                 vmaddr = __gmap_translate(parent, paddr);
1219                 if (IS_ERR_VALUE(vmaddr))
1220                         return vmaddr;
1221                 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
1222                 if (!rmap)
1223                         return -ENOMEM;
1224                 rmap->raddr = raddr;
1225                 rc = radix_tree_preload(GFP_KERNEL);
1226                 if (rc) {
1227                         kfree(rmap);
1228                         return rc;
1229                 }
1230                 rc = -EAGAIN;
1231                 ptep = gmap_pte_op_walk(parent, paddr, &ptl);
1232                 if (ptep) {
1233                         spin_lock(&sg->guest_table_lock);
1234                         rc = ptep_force_prot(parent->mm, paddr, ptep, PROT_READ,
1235                                              PGSTE_VSIE_BIT);
1236                         if (!rc)
1237                                 gmap_insert_rmap(sg, vmaddr, rmap);
1238                         spin_unlock(&sg->guest_table_lock);
1239                         gmap_pte_op_end(ptl);
1240                 }
1241                 radix_tree_preload_end();
1242                 if (rc) {
1243                         kfree(rmap);
1244                         rc = gmap_pte_op_fixup(parent, paddr, vmaddr, PROT_READ);
1245                         if (rc)
1246                                 return rc;
1247                         continue;
1248                 }
1249                 paddr += PAGE_SIZE;
1250                 len -= PAGE_SIZE;
1251         }
1252         return 0;
1253 }
1254 
1255 #define _SHADOW_RMAP_MASK       0x7
1256 #define _SHADOW_RMAP_REGION1    0x5
1257 #define _SHADOW_RMAP_REGION2    0x4
1258 #define _SHADOW_RMAP_REGION3    0x3
1259 #define _SHADOW_RMAP_SEGMENT    0x2
1260 #define _SHADOW_RMAP_PGTABLE    0x1
1261 
1262 /**
1263  * gmap_idte_one - invalidate a single region or segment table entry
1264  * @asce: region or segment table *origin* + table-type bits
1265  * @vaddr: virtual address to identify the table entry to flush
1266  *
1267  * The invalid bit of a single region or segment table entry is set
1268  * and the associated TLB entries depending on the entry are flushed.
1269  * The table-type of the @asce identifies the portion of the @vaddr
1270  * that is used as the invalidation index.
1271  */
1272 static inline void gmap_idte_one(unsigned long asce, unsigned long vaddr)
1273 {
1274         asm volatile(
1275                 "       .insn   rrf,0xb98e0000,%0,%1,0,0"
1276                 : : "a" (asce), "a" (vaddr) : "cc", "memory");
1277 }
1278 
1279 /**
1280  * gmap_unshadow_page - remove a page from a shadow page table
1281  * @sg: pointer to the shadow guest address space structure
1282  * @raddr: rmap address in the shadow guest address space
1283  *
1284  * Called with the sg->guest_table_lock
1285  */
1286 static void gmap_unshadow_page(struct gmap *sg, unsigned long raddr)
1287 {
1288         unsigned long *table;
1289 
1290         BUG_ON(!gmap_is_shadow(sg));
1291         table = gmap_table_walk(sg, raddr, 0); /* get page table pointer */
1292         if (!table || *table & _PAGE_INVALID)
1293                 return;
1294         gmap_call_notifier(sg, raddr, raddr + _PAGE_SIZE - 1);
1295         ptep_unshadow_pte(sg->mm, raddr, (pte_t *) table);
1296 }
1297 
1298 /**
1299  * __gmap_unshadow_pgt - remove all entries from a shadow page table
1300  * @sg: pointer to the shadow guest address space structure
1301  * @raddr: rmap address in the shadow guest address space
1302  * @pgt: pointer to the start of a shadow page table
1303  *
1304  * Called with the sg->guest_table_lock
1305  */
1306 static void __gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr,
1307                                 unsigned long *pgt)
1308 {
1309         int i;
1310 
1311         BUG_ON(!gmap_is_shadow(sg));
1312         for (i = 0; i < _PAGE_ENTRIES; i++, raddr += _PAGE_SIZE)
1313                 pgt[i] = _PAGE_INVALID;
1314 }
1315 
1316 /**
1317  * gmap_unshadow_pgt - remove a shadow page table from a segment entry
1318  * @sg: pointer to the shadow guest address space structure
1319  * @raddr: address in the shadow guest address space
1320  *
1321  * Called with the sg->guest_table_lock
1322  */
1323 static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
1324 {
1325         unsigned long sto, *ste, *pgt;
1326         struct page *page;
1327 
1328         BUG_ON(!gmap_is_shadow(sg));
1329         ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
1330         if (!ste || !(*ste & _SEGMENT_ENTRY_ORIGIN))
1331                 return;
1332         gmap_call_notifier(sg, raddr, raddr + _SEGMENT_SIZE - 1);
1333         sto = (unsigned long) (ste - ((raddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT));
1334         gmap_idte_one(sto | _ASCE_TYPE_SEGMENT, raddr);
1335         pgt = (unsigned long *)(*ste & _SEGMENT_ENTRY_ORIGIN);
1336         *ste = _SEGMENT_ENTRY_EMPTY;
1337         __gmap_unshadow_pgt(sg, raddr, pgt);
1338         /* Free page table */
1339         page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1340         list_del(&page->lru);
1341         page_table_free_pgste(page);
1342 }
1343 
1344 /**
1345  * __gmap_unshadow_sgt - remove all entries from a shadow segment table
1346  * @sg: pointer to the shadow guest address space structure
1347  * @raddr: rmap address in the shadow guest address space
1348  * @sgt: pointer to the start of a shadow segment table
1349  *
1350  * Called with the sg->guest_table_lock
1351  */
1352 static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
1353                                 unsigned long *sgt)
1354 {
1355         unsigned long *pgt;
1356         struct page *page;
1357         int i;
1358 
1359         BUG_ON(!gmap_is_shadow(sg));
1360         for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
1361                 if (!(sgt[i] & _SEGMENT_ENTRY_ORIGIN))
1362                         continue;
1363                 pgt = (unsigned long *)(sgt[i] & _REGION_ENTRY_ORIGIN);
1364                 sgt[i] = _SEGMENT_ENTRY_EMPTY;
1365                 __gmap_unshadow_pgt(sg, raddr, pgt);
1366                 /* Free page table */
1367                 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1368                 list_del(&page->lru);
1369                 page_table_free_pgste(page);
1370         }
1371 }
1372 
1373 /**
1374  * gmap_unshadow_sgt - remove a shadow segment table from a region-3 entry
1375  * @sg: pointer to the shadow guest address space structure
1376  * @raddr: rmap address in the shadow guest address space
1377  *
1378  * Called with the shadow->guest_table_lock
1379  */
1380 static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
1381 {
1382         unsigned long r3o, *r3e, *sgt;
1383         struct page *page;
1384 
1385         BUG_ON(!gmap_is_shadow(sg));
1386         r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
1387         if (!r3e || !(*r3e & _REGION_ENTRY_ORIGIN))
1388                 return;
1389         gmap_call_notifier(sg, raddr, raddr + _REGION3_SIZE - 1);
1390         r3o = (unsigned long) (r3e - ((raddr & _REGION3_INDEX) >> _REGION3_SHIFT));
1391         gmap_idte_one(r3o | _ASCE_TYPE_REGION3, raddr);
1392         sgt = (unsigned long *)(*r3e & _REGION_ENTRY_ORIGIN);
1393         *r3e = _REGION3_ENTRY_EMPTY;
1394         __gmap_unshadow_sgt(sg, raddr, sgt);
1395         /* Free segment table */
1396         page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1397         list_del(&page->lru);
1398         __free_pages(page, CRST_ALLOC_ORDER);
1399 }
1400 
1401 /**
1402  * __gmap_unshadow_r3t - remove all entries from a shadow region-3 table
1403  * @sg: pointer to the shadow guest address space structure
1404  * @raddr: address in the shadow guest address space
1405  * @r3t: pointer to the start of a shadow region-3 table
1406  *
1407  * Called with the sg->guest_table_lock
1408  */
1409 static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
1410                                 unsigned long *r3t)
1411 {
1412         unsigned long *sgt;
1413         struct page *page;
1414         int i;
1415 
1416         BUG_ON(!gmap_is_shadow(sg));
1417         for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
1418                 if (!(r3t[i] & _REGION_ENTRY_ORIGIN))
1419                         continue;
1420                 sgt = (unsigned long *)(r3t[i] & _REGION_ENTRY_ORIGIN);
1421                 r3t[i] = _REGION3_ENTRY_EMPTY;
1422                 __gmap_unshadow_sgt(sg, raddr, sgt);
1423                 /* Free segment table */
1424                 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1425                 list_del(&page->lru);
1426                 __free_pages(page, CRST_ALLOC_ORDER);
1427         }
1428 }
1429 
1430 /**
1431  * gmap_unshadow_r3t - remove a shadow region-3 table from a region-2 entry
1432  * @sg: pointer to the shadow guest address space structure
1433  * @raddr: rmap address in the shadow guest address space
1434  *
1435  * Called with the sg->guest_table_lock
1436  */
1437 static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
1438 {
1439         unsigned long r2o, *r2e, *r3t;
1440         struct page *page;
1441 
1442         BUG_ON(!gmap_is_shadow(sg));
1443         r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
1444         if (!r2e || !(*r2e & _REGION_ENTRY_ORIGIN))
1445                 return;
1446         gmap_call_notifier(sg, raddr, raddr + _REGION2_SIZE - 1);
1447         r2o = (unsigned long) (r2e - ((raddr & _REGION2_INDEX) >> _REGION2_SHIFT));
1448         gmap_idte_one(r2o | _ASCE_TYPE_REGION2, raddr);
1449         r3t = (unsigned long *)(*r2e & _REGION_ENTRY_ORIGIN);
1450         *r2e = _REGION2_ENTRY_EMPTY;
1451         __gmap_unshadow_r3t(sg, raddr, r3t);
1452         /* Free region 3 table */
1453         page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1454         list_del(&page->lru);
1455         __free_pages(page, CRST_ALLOC_ORDER);
1456 }
1457 
1458 /**
1459  * __gmap_unshadow_r2t - remove all entries from a shadow region-2 table
1460  * @sg: pointer to the shadow guest address space structure
1461  * @raddr: rmap address in the shadow guest address space
1462  * @r2t: pointer to the start of a shadow region-2 table
1463  *
1464  * Called with the sg->guest_table_lock
1465  */
1466 static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
1467                                 unsigned long *r2t)
1468 {
1469         unsigned long *r3t;
1470         struct page *page;
1471         int i;
1472 
1473         BUG_ON(!gmap_is_shadow(sg));
1474         for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
1475                 if (!(r2t[i] & _REGION_ENTRY_ORIGIN))
1476                         continue;
1477                 r3t = (unsigned long *)(r2t[i] & _REGION_ENTRY_ORIGIN);
1478                 r2t[i] = _REGION2_ENTRY_EMPTY;
1479                 __gmap_unshadow_r3t(sg, raddr, r3t);
1480                 /* Free region 3 table */
1481                 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1482                 list_del(&page->lru);
1483                 __free_pages(page, CRST_ALLOC_ORDER);
1484         }
1485 }
1486 
1487 /**
1488  * gmap_unshadow_r2t - remove a shadow region-2 table from a region-1 entry
1489  * @sg: pointer to the shadow guest address space structure
1490  * @raddr: rmap address in the shadow guest address space
1491  *
1492  * Called with the sg->guest_table_lock
1493  */
1494 static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
1495 {
1496         unsigned long r1o, *r1e, *r2t;
1497         struct page *page;
1498 
1499         BUG_ON(!gmap_is_shadow(sg));
1500         r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
1501         if (!r1e || !(*r1e & _REGION_ENTRY_ORIGIN))
1502                 return;
1503         gmap_call_notifier(sg, raddr, raddr + _REGION1_SIZE - 1);
1504         r1o = (unsigned long) (r1e - ((raddr & _REGION1_INDEX) >> _REGION1_SHIFT));
1505         gmap_idte_one(r1o | _ASCE_TYPE_REGION1, raddr);
1506         r2t = (unsigned long *)(*r1e & _REGION_ENTRY_ORIGIN);
1507         *r1e = _REGION1_ENTRY_EMPTY;
1508         __gmap_unshadow_r2t(sg, raddr, r2t);
1509         /* Free region 2 table */
1510         page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1511         list_del(&page->lru);
1512         __free_pages(page, CRST_ALLOC_ORDER);
1513 }
1514 
1515 /**
1516  * __gmap_unshadow_r1t - remove all entries from a shadow region-1 table
1517  * @sg: pointer to the shadow guest address space structure
1518  * @raddr: rmap address in the shadow guest address space
1519  * @r1t: pointer to the start of a shadow region-1 table
1520  *
1521  * Called with the shadow->guest_table_lock
1522  */
1523 static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
1524                                 unsigned long *r1t)
1525 {
1526         unsigned long asce, *r2t;
1527         struct page *page;
1528         int i;
1529 
1530         BUG_ON(!gmap_is_shadow(sg));
1531         asce = (unsigned long) r1t | _ASCE_TYPE_REGION1;
1532         for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION1_SIZE) {
1533                 if (!(r1t[i] & _REGION_ENTRY_ORIGIN))
1534                         continue;
1535                 r2t = (unsigned long *)(r1t[i] & _REGION_ENTRY_ORIGIN);
1536                 __gmap_unshadow_r2t(sg, raddr, r2t);
1537                 /* Clear entry and flush translation r1t -> r2t */
1538                 gmap_idte_one(asce, raddr);
1539                 r1t[i] = _REGION1_ENTRY_EMPTY;
1540                 /* Free region 2 table */
1541                 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1542                 list_del(&page->lru);
1543                 __free_pages(page, CRST_ALLOC_ORDER);
1544         }
1545 }
1546 
1547 /**
1548  * gmap_unshadow - remove a shadow page table completely
1549  * @sg: pointer to the shadow guest address space structure
1550  *
1551  * Called with sg->guest_table_lock
1552  */
1553 static void gmap_unshadow(struct gmap *sg)
1554 {
1555         unsigned long *table;
1556 
1557         BUG_ON(!gmap_is_shadow(sg));
1558         if (sg->removed)
1559                 return;
1560         sg->removed = 1;
1561         gmap_call_notifier(sg, 0, -1UL);
1562         gmap_flush_tlb(sg);
1563         table = (unsigned long *)(sg->asce & _ASCE_ORIGIN);
1564         switch (sg->asce & _ASCE_TYPE_MASK) {
1565         case _ASCE_TYPE_REGION1:
1566                 __gmap_unshadow_r1t(sg, 0, table);
1567                 break;
1568         case _ASCE_TYPE_REGION2:
1569                 __gmap_unshadow_r2t(sg, 0, table);
1570                 break;
1571         case _ASCE_TYPE_REGION3:
1572                 __gmap_unshadow_r3t(sg, 0, table);
1573                 break;
1574         case _ASCE_TYPE_SEGMENT:
1575                 __gmap_unshadow_sgt(sg, 0, table);
1576                 break;
1577         }
1578 }
1579 
1580 /**
1581  * gmap_find_shadow - find a specific asce in the list of shadow tables
1582  * @parent: pointer to the parent gmap
1583  * @asce: ASCE for which the shadow table is created
1584  * @edat_level: edat level to be used for the shadow translation
1585  *
1586  * Returns the pointer to a gmap if a shadow table with the given asce is
1587  * already available, ERR_PTR(-EAGAIN) if another one is just being created,
1588  * otherwise NULL
1589  */
1590 static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
1591                                      int edat_level)
1592 {
1593         struct gmap *sg;
1594 
1595         list_for_each_entry(sg, &parent->children, list) {
1596                 if (sg->orig_asce != asce || sg->edat_level != edat_level ||
1597                     sg->removed)
1598                         continue;
1599                 if (!sg->initialized)
1600                         return ERR_PTR(-EAGAIN);
1601                 refcount_inc(&sg->ref_count);
1602                 return sg;
1603         }
1604         return NULL;
1605 }
1606 
1607 /**
1608  * gmap_shadow_valid - check if a shadow guest address space matches the
1609  *                     given properties and is still valid
1610  * @sg: pointer to the shadow guest address space structure
1611  * @asce: ASCE for which the shadow table is requested
1612  * @edat_level: edat level to be used for the shadow translation
1613  *
1614  * Returns 1 if the gmap shadow is still valid and matches the given
1615  * properties, the caller can continue using it. Returns 0 otherwise, the
1616  * caller has to request a new shadow gmap in this case.
1617  *
1618  */
1619 int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
1620 {
1621         if (sg->removed)
1622                 return 0;
1623         return sg->orig_asce == asce && sg->edat_level == edat_level;
1624 }
1625 EXPORT_SYMBOL_GPL(gmap_shadow_valid);
1626 
1627 /**
1628  * gmap_shadow - create/find a shadow guest address space
1629  * @parent: pointer to the parent gmap
1630  * @asce: ASCE for which the shadow table is created
1631  * @edat_level: edat level to be used for the shadow translation
1632  *
1633  * The pages of the top level page table referred by the asce parameter
1634  * will be set to read-only and marked in the PGSTEs of the kvm process.
1635  * The shadow table will be removed automatically on any change to the
1636  * PTE mapping for the source table.
1637  *
1638  * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
1639  * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
1640  * parent gmap table could not be protected.
1641  */
1642 struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
1643                          int edat_level)
1644 {
1645         struct gmap *sg, *new;
1646         unsigned long limit;
1647         int rc;
1648 
1649         BUG_ON(parent->mm->context.allow_gmap_hpage_1m);
1650         BUG_ON(gmap_is_shadow(parent));
1651         spin_lock(&parent->shadow_lock);
1652         sg = gmap_find_shadow(parent, asce, edat_level);
1653         spin_unlock(&parent->shadow_lock);
1654         if (sg)
1655                 return sg;
1656         /* Create a new shadow gmap */
1657         limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
1658         if (asce & _ASCE_REAL_SPACE)
1659                 limit = -1UL;
1660         new = gmap_alloc(limit);
1661         if (!new)
1662                 return ERR_PTR(-ENOMEM);
1663         new->mm = parent->mm;
1664         new->parent = gmap_get(parent);
1665         new->orig_asce = asce;
1666         new->edat_level = edat_level;
1667         new->initialized = false;
1668         spin_lock(&parent->shadow_lock);
1669         /* Recheck if another CPU created the same shadow */
1670         sg = gmap_find_shadow(parent, asce, edat_level);
1671         if (sg) {
1672                 spin_unlock(&parent->shadow_lock);
1673                 gmap_free(new);
1674                 return sg;
1675         }
1676         if (asce & _ASCE_REAL_SPACE) {
1677                 /* only allow one real-space gmap shadow */
1678                 list_for_each_entry(sg, &parent->children, list) {
1679                         if (sg->orig_asce & _ASCE_REAL_SPACE) {
1680                                 spin_lock(&sg->guest_table_lock);
1681                                 gmap_unshadow(sg);
1682                                 spin_unlock(&sg->guest_table_lock);
1683                                 list_del(&sg->list);
1684                                 gmap_put(sg);
1685                                 break;
1686                         }
1687                 }
1688         }
1689         refcount_set(&new->ref_count, 2);
1690         list_add(&new->list, &parent->children);
1691         if (asce & _ASCE_REAL_SPACE) {
1692                 /* nothing to protect, return right away */
1693                 new->initialized = true;
1694                 spin_unlock(&parent->shadow_lock);
1695                 return new;
1696         }
1697         spin_unlock(&parent->shadow_lock);
1698         /* protect after insertion, so it will get properly invalidated */
1699         down_read(&parent->mm->mmap_sem);
1700         rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
1701                                 ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
1702                                 PROT_READ, GMAP_NOTIFY_SHADOW);
1703         up_read(&parent->mm->mmap_sem);
1704         spin_lock(&parent->shadow_lock);
1705         new->initialized = true;
1706         if (rc) {
1707                 list_del(&new->list);
1708                 gmap_free(new);
1709                 new = ERR_PTR(rc);
1710         }
1711         spin_unlock(&parent->shadow_lock);
1712         return new;
1713 }
1714 EXPORT_SYMBOL_GPL(gmap_shadow);
1715 
1716 /**
1717  * gmap_shadow_r2t - create an empty shadow region 2 table
1718  * @sg: pointer to the shadow guest address space structure
1719  * @saddr: faulting address in the shadow gmap
1720  * @r2t: parent gmap address of the region 2 table to get shadowed
1721  * @fake: r2t references contiguous guest memory block, not a r2t
1722  *
1723  * The r2t parameter specifies the address of the source table. The
1724  * four pages of the source table are made read-only in the parent gmap
1725  * address space. A write to the source table area @r2t will automatically
1726  * remove the shadow r2 table and all of its decendents.
1727  *
1728  * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1729  * shadow table structure is incomplete, -ENOMEM if out of memory and
1730  * -EFAULT if an address in the parent gmap could not be resolved.
1731  *
1732  * Called with sg->mm->mmap_sem in read.
1733  */
1734 int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
1735                     int fake)
1736 {
1737         unsigned long raddr, origin, offset, len;
1738         unsigned long *s_r2t, *table;
1739         struct page *page;
1740         int rc;
1741 
1742         BUG_ON(!gmap_is_shadow(sg));
1743         /* Allocate a shadow region second table */
1744         page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1745         if (!page)
1746                 return -ENOMEM;
1747         page->index = r2t & _REGION_ENTRY_ORIGIN;
1748         if (fake)
1749                 page->index |= GMAP_SHADOW_FAKE_TABLE;
1750         s_r2t = (unsigned long *) page_to_phys(page);
1751         /* Install shadow region second table */
1752         spin_lock(&sg->guest_table_lock);
1753         table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
1754         if (!table) {
1755                 rc = -EAGAIN;           /* Race with unshadow */
1756                 goto out_free;
1757         }
1758         if (!(*table & _REGION_ENTRY_INVALID)) {
1759                 rc = 0;                 /* Already established */
1760                 goto out_free;
1761         } else if (*table & _REGION_ENTRY_ORIGIN) {
1762                 rc = -EAGAIN;           /* Race with shadow */
1763                 goto out_free;
1764         }
1765         crst_table_init(s_r2t, _REGION2_ENTRY_EMPTY);
1766         /* mark as invalid as long as the parent table is not protected */
1767         *table = (unsigned long) s_r2t | _REGION_ENTRY_LENGTH |
1768                  _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
1769         if (sg->edat_level >= 1)
1770                 *table |= (r2t & _REGION_ENTRY_PROTECT);
1771         list_add(&page->lru, &sg->crst_list);
1772         if (fake) {
1773                 /* nothing to protect for fake tables */
1774                 *table &= ~_REGION_ENTRY_INVALID;
1775                 spin_unlock(&sg->guest_table_lock);
1776                 return 0;
1777         }
1778         spin_unlock(&sg->guest_table_lock);
1779         /* Make r2t read-only in parent gmap page table */
1780         raddr = (saddr & _REGION1_MASK) | _SHADOW_RMAP_REGION1;
1781         origin = r2t & _REGION_ENTRY_ORIGIN;
1782         offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1783         len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1784         rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1785         spin_lock(&sg->guest_table_lock);
1786         if (!rc) {
1787                 table = gmap_table_walk(sg, saddr, 4);
1788                 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1789                               (unsigned long) s_r2t)
1790                         rc = -EAGAIN;           /* Race with unshadow */
1791                 else
1792                         *table &= ~_REGION_ENTRY_INVALID;
1793         } else {
1794                 gmap_unshadow_r2t(sg, raddr);
1795         }
1796         spin_unlock(&sg->guest_table_lock);
1797         return rc;
1798 out_free:
1799         spin_unlock(&sg->guest_table_lock);
1800         __free_pages(page, CRST_ALLOC_ORDER);
1801         return rc;
1802 }
1803 EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
1804 
1805 /**
1806  * gmap_shadow_r3t - create a shadow region 3 table
1807  * @sg: pointer to the shadow guest address space structure
1808  * @saddr: faulting address in the shadow gmap
1809  * @r3t: parent gmap address of the region 3 table to get shadowed
1810  * @fake: r3t references contiguous guest memory block, not a r3t
1811  *
1812  * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1813  * shadow table structure is incomplete, -ENOMEM if out of memory and
1814  * -EFAULT if an address in the parent gmap could not be resolved.
1815  *
1816  * Called with sg->mm->mmap_sem in read.
1817  */
1818 int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
1819                     int fake)
1820 {
1821         unsigned long raddr, origin, offset, len;
1822         unsigned long *s_r3t, *table;
1823         struct page *page;
1824         int rc;
1825 
1826         BUG_ON(!gmap_is_shadow(sg));
1827         /* Allocate a shadow region second table */
1828         page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1829         if (!page)
1830                 return -ENOMEM;
1831         page->index = r3t & _REGION_ENTRY_ORIGIN;
1832         if (fake)
1833                 page->index |= GMAP_SHADOW_FAKE_TABLE;
1834         s_r3t = (unsigned long *) page_to_phys(page);
1835         /* Install shadow region second table */
1836         spin_lock(&sg->guest_table_lock);
1837         table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
1838         if (!table) {
1839                 rc = -EAGAIN;           /* Race with unshadow */
1840                 goto out_free;
1841         }
1842         if (!(*table & _REGION_ENTRY_INVALID)) {
1843                 rc = 0;                 /* Already established */
1844                 goto out_free;
1845         } else if (*table & _REGION_ENTRY_ORIGIN) {
1846                 rc = -EAGAIN;           /* Race with shadow */
1847                 goto out_free;
1848         }
1849         crst_table_init(s_r3t, _REGION3_ENTRY_EMPTY);
1850         /* mark as invalid as long as the parent table is not protected */
1851         *table = (unsigned long) s_r3t | _REGION_ENTRY_LENGTH |
1852                  _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
1853         if (sg->edat_level >= 1)
1854                 *table |= (r3t & _REGION_ENTRY_PROTECT);
1855         list_add(&page->lru, &sg->crst_list);
1856         if (fake) {
1857                 /* nothing to protect for fake tables */
1858                 *table &= ~_REGION_ENTRY_INVALID;
1859                 spin_unlock(&sg->guest_table_lock);
1860                 return 0;
1861         }
1862         spin_unlock(&sg->guest_table_lock);
1863         /* Make r3t read-only in parent gmap page table */
1864         raddr = (saddr & _REGION2_MASK) | _SHADOW_RMAP_REGION2;
1865         origin = r3t & _REGION_ENTRY_ORIGIN;
1866         offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1867         len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1868         rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1869         spin_lock(&sg->guest_table_lock);
1870         if (!rc) {
1871                 table = gmap_table_walk(sg, saddr, 3);
1872                 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1873                               (unsigned long) s_r3t)
1874                         rc = -EAGAIN;           /* Race with unshadow */
1875                 else
1876                         *table &= ~_REGION_ENTRY_INVALID;
1877         } else {
1878                 gmap_unshadow_r3t(sg, raddr);
1879         }
1880         spin_unlock(&sg->guest_table_lock);
1881         return rc;
1882 out_free:
1883         spin_unlock(&sg->guest_table_lock);
1884         __free_pages(page, CRST_ALLOC_ORDER);
1885         return rc;
1886 }
1887 EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
1888 
1889 /**
1890  * gmap_shadow_sgt - create a shadow segment table
1891  * @sg: pointer to the shadow guest address space structure
1892  * @saddr: faulting address in the shadow gmap
1893  * @sgt: parent gmap address of the segment table to get shadowed
1894  * @fake: sgt references contiguous guest memory block, not a sgt
1895  *
1896  * Returns: 0 if successfully shadowed or already shadowed, -EAGAIN if the
1897  * shadow table structure is incomplete, -ENOMEM if out of memory and
1898  * -EFAULT if an address in the parent gmap could not be resolved.
1899  *
1900  * Called with sg->mm->mmap_sem in read.
1901  */
1902 int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
1903                     int fake)
1904 {
1905         unsigned long raddr, origin, offset, len;
1906         unsigned long *s_sgt, *table;
1907         struct page *page;
1908         int rc;
1909 
1910         BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
1911         /* Allocate a shadow segment table */
1912         page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1913         if (!page)
1914                 return -ENOMEM;
1915         page->index = sgt & _REGION_ENTRY_ORIGIN;
1916         if (fake)
1917                 page->index |= GMAP_SHADOW_FAKE_TABLE;
1918         s_sgt = (unsigned long *) page_to_phys(page);
1919         /* Install shadow region second table */
1920         spin_lock(&sg->guest_table_lock);
1921         table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
1922         if (!table) {
1923                 rc = -EAGAIN;           /* Race with unshadow */
1924                 goto out_free;
1925         }
1926         if (!(*table & _REGION_ENTRY_INVALID)) {
1927                 rc = 0;                 /* Already established */
1928                 goto out_free;
1929         } else if (*table & _REGION_ENTRY_ORIGIN) {
1930                 rc = -EAGAIN;           /* Race with shadow */
1931                 goto out_free;
1932         }
1933         crst_table_init(s_sgt, _SEGMENT_ENTRY_EMPTY);
1934         /* mark as invalid as long as the parent table is not protected */
1935         *table = (unsigned long) s_sgt | _REGION_ENTRY_LENGTH |
1936                  _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
1937         if (sg->edat_level >= 1)
1938                 *table |= sgt & _REGION_ENTRY_PROTECT;
1939         list_add(&page->lru, &sg->crst_list);
1940         if (fake) {
1941                 /* nothing to protect for fake tables */
1942                 *table &= ~_REGION_ENTRY_INVALID;
1943                 spin_unlock(&sg->guest_table_lock);
1944                 return 0;
1945         }
1946         spin_unlock(&sg->guest_table_lock);
1947         /* Make sgt read-only in parent gmap page table */
1948         raddr = (saddr & _REGION3_MASK) | _SHADOW_RMAP_REGION3;
1949         origin = sgt & _REGION_ENTRY_ORIGIN;
1950         offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1951         len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1952         rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1953         spin_lock(&sg->guest_table_lock);
1954         if (!rc) {
1955                 table = gmap_table_walk(sg, saddr, 2);
1956                 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1957                               (unsigned long) s_sgt)
1958                         rc = -EAGAIN;           /* Race with unshadow */
1959                 else
1960                         *table &= ~_REGION_ENTRY_INVALID;
1961         } else {
1962                 gmap_unshadow_sgt(sg, raddr);
1963         }
1964         spin_unlock(&sg->guest_table_lock);
1965         return rc;
1966 out_free:
1967         spin_unlock(&sg->guest_table_lock);
1968         __free_pages(page, CRST_ALLOC_ORDER);
1969         return rc;
1970 }
1971 EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
1972 
1973 /**
1974  * gmap_shadow_lookup_pgtable - find a shadow page table
1975  * @sg: pointer to the shadow guest address space structure
1976  * @saddr: the address in the shadow aguest address space
1977  * @pgt: parent gmap address of the page table to get shadowed
1978  * @dat_protection: if the pgtable is marked as protected by dat
1979  * @fake: pgt references contiguous guest memory block, not a pgtable
1980  *
1981  * Returns 0 if the shadow page table was found and -EAGAIN if the page
1982  * table was not found.
1983  *
1984  * Called with sg->mm->mmap_sem in read.
1985  */
1986 int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
1987                            unsigned long *pgt, int *dat_protection,
1988                            int *fake)
1989 {
1990         unsigned long *table;
1991         struct page *page;
1992         int rc;
1993 
1994         BUG_ON(!gmap_is_shadow(sg));
1995         spin_lock(&sg->guest_table_lock);
1996         table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
1997         if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
1998                 /* Shadow page tables are full pages (pte+pgste) */
1999                 page = pfn_to_page(*table >> PAGE_SHIFT);
2000                 *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
2001                 *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
2002                 *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
2003                 rc = 0;
2004         } else  {
2005                 rc = -EAGAIN;
2006         }
2007         spin_unlock(&sg->guest_table_lock);
2008         return rc;
2009 
2010 }
2011 EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
2012 
2013 /**
2014  * gmap_shadow_pgt - instantiate a shadow page table
2015  * @sg: pointer to the shadow guest address space structure
2016  * @saddr: faulting address in the shadow gmap
2017  * @pgt: parent gmap address of the page table to get shadowed
2018  * @fake: pgt references contiguous guest memory block, not a pgtable
2019  *
2020  * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
2021  * shadow table structure is incomplete, -ENOMEM if out of memory,
2022  * -EFAULT if an address in the parent gmap could not be resolved and
2023  *
2024  * Called with gmap->mm->mmap_sem in read
2025  */
2026 int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
2027                     int fake)
2028 {
2029         unsigned long raddr, origin;
2030         unsigned long *s_pgt, *table;
2031         struct page *page;
2032         int rc;
2033 
2034         BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
2035         /* Allocate a shadow page table */
2036         page = page_table_alloc_pgste(sg->mm);
2037         if (!page)
2038                 return -ENOMEM;
2039         page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
2040         if (fake)
2041                 page->index |= GMAP_SHADOW_FAKE_TABLE;
2042         s_pgt = (unsigned long *) page_to_phys(page);
2043         /* Install shadow page table */
2044         spin_lock(&sg->guest_table_lock);
2045         table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
2046         if (!table) {
2047                 rc = -EAGAIN;           /* Race with unshadow */
2048                 goto out_free;
2049         }
2050         if (!(*table & _SEGMENT_ENTRY_INVALID)) {
2051                 rc = 0;                 /* Already established */
2052                 goto out_free;
2053         } else if (*table & _SEGMENT_ENTRY_ORIGIN) {
2054                 rc = -EAGAIN;           /* Race with shadow */
2055                 goto out_free;
2056         }
2057         /* mark as invalid as long as the parent table is not protected */
2058         *table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
2059                  (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
2060         list_add(&page->lru, &sg->pt_list);
2061         if (fake) {
2062                 /* nothing to protect for fake tables */
2063                 *table &= ~_SEGMENT_ENTRY_INVALID;
2064                 spin_unlock(&sg->guest_table_lock);
2065                 return 0;
2066         }
2067         spin_unlock(&sg->guest_table_lock);
2068         /* Make pgt read-only in parent gmap page table (not the pgste) */
2069         raddr = (saddr & _SEGMENT_MASK) | _SHADOW_RMAP_SEGMENT;
2070         origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
2071         rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE);
2072         spin_lock(&sg->guest_table_lock);
2073         if (!rc) {
2074                 table = gmap_table_walk(sg, saddr, 1);
2075                 if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) !=
2076                               (unsigned long) s_pgt)
2077                         rc = -EAGAIN;           /* Race with unshadow */
2078                 else
2079                         *table &= ~_SEGMENT_ENTRY_INVALID;
2080         } else {
2081                 gmap_unshadow_pgt(sg, raddr);
2082         }
2083         spin_unlock(&sg->guest_table_lock);
2084         return rc;
2085 out_free:
2086         spin_unlock(&sg->guest_table_lock);
2087         page_table_free_pgste(page);
2088         return rc;
2089 
2090 }
2091 EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
2092 
2093 /**
2094  * gmap_shadow_page - create a shadow page mapping
2095  * @sg: pointer to the shadow guest address space structure
2096  * @saddr: faulting address in the shadow gmap
2097  * @pte: pte in parent gmap address space to get shadowed
2098  *
2099  * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
2100  * shadow table structure is incomplete, -ENOMEM if out of memory and
2101  * -EFAULT if an address in the parent gmap could not be resolved.
2102  *
2103  * Called with sg->mm->mmap_sem in read.
2104  */
2105 int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
2106 {
2107         struct gmap *parent;
2108         struct gmap_rmap *rmap;
2109         unsigned long vmaddr, paddr;
2110         spinlock_t *ptl;
2111         pte_t *sptep, *tptep;
2112         int prot;
2113         int rc;
2114 
2115         BUG_ON(!gmap_is_shadow(sg));
2116         parent = sg->parent;
2117         prot = (pte_val(pte) & _PAGE_PROTECT) ? PROT_READ : PROT_WRITE;
2118 
2119         rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
2120         if (!rmap)
2121                 return -ENOMEM;
2122         rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
2123 
2124         while (1) {
2125                 paddr = pte_val(pte) & PAGE_MASK;
2126                 vmaddr = __gmap_translate(parent, paddr);
2127                 if (IS_ERR_VALUE(vmaddr)) {
2128                         rc = vmaddr;
2129                         break;
2130                 }
2131                 rc = radix_tree_preload(GFP_KERNEL);
2132                 if (rc)
2133                         break;
2134                 rc = -EAGAIN;
2135                 sptep = gmap_pte_op_walk(parent, paddr, &ptl);
2136                 if (sptep) {
2137                         spin_lock(&sg->guest_table_lock);
2138                         /* Get page table pointer */
2139                         tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
2140                         if (!tptep) {
2141                                 spin_unlock(&sg->guest_table_lock);
2142                                 gmap_pte_op_end(ptl);
2143                                 radix_tree_preload_end();
2144                                 break;
2145                         }
2146                         rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
2147                         if (rc > 0) {
2148                                 /* Success and a new mapping */
2149                                 gmap_insert_rmap(sg, vmaddr, rmap);
2150                                 rmap = NULL;
2151                                 rc = 0;
2152                         }
2153                         gmap_pte_op_end(ptl);
2154                         spin_unlock(&sg->guest_table_lock);
2155                 }
2156                 radix_tree_preload_end();
2157                 if (!rc)
2158                         break;
2159                 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
2160                 if (rc)
2161                         break;
2162         }
2163         kfree(rmap);
2164         return rc;
2165 }
2166 EXPORT_SYMBOL_GPL(gmap_shadow_page);
2167 
2168 /**
2169  * gmap_shadow_notify - handle notifications for shadow gmap
2170  *
2171  * Called with sg->parent->shadow_lock.
2172  */
2173 static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
2174                                unsigned long gaddr)
2175 {
2176         struct gmap_rmap *rmap, *rnext, *head;
2177         unsigned long start, end, bits, raddr;
2178 
2179         BUG_ON(!gmap_is_shadow(sg));
2180 
2181         spin_lock(&sg->guest_table_lock);
2182         if (sg->removed) {
2183                 spin_unlock(&sg->guest_table_lock);
2184                 return;
2185         }
2186         /* Check for top level table */
2187         start = sg->orig_asce & _ASCE_ORIGIN;
2188         end = start + ((sg->orig_asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE;
2189         if (!(sg->orig_asce & _ASCE_REAL_SPACE) && gaddr >= start &&
2190             gaddr < end) {
2191                 /* The complete shadow table has to go */
2192                 gmap_unshadow(sg);
2193                 spin_unlock(&sg->guest_table_lock);
2194                 list_del(&sg->list);
2195                 gmap_put(sg);
2196                 return;
2197         }
2198         /* Remove the page table tree from on specific entry */
2199         head = radix_tree_delete(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
2200         gmap_for_each_rmap_safe(rmap, rnext, head) {
2201                 bits = rmap->raddr & _SHADOW_RMAP_MASK;
2202                 raddr = rmap->raddr ^ bits;
2203                 switch (bits) {
2204                 case _SHADOW_RMAP_REGION1:
2205                         gmap_unshadow_r2t(sg, raddr);
2206                         break;
2207                 case _SHADOW_RMAP_REGION2:
2208                         gmap_unshadow_r3t(sg, raddr);
2209                         break;
2210                 case _SHADOW_RMAP_REGION3:
2211                         gmap_unshadow_sgt(sg, raddr);
2212                         break;
2213                 case _SHADOW_RMAP_SEGMENT:
2214                         gmap_unshadow_pgt(sg, raddr);
2215                         break;
2216                 case _SHADOW_RMAP_PGTABLE:
2217                         gmap_unshadow_page(sg, raddr);
2218                         break;
2219                 }
2220                 kfree(rmap);
2221         }
2222         spin_unlock(&sg->guest_table_lock);
2223 }
2224 
2225 /**
2226  * ptep_notify - call all invalidation callbacks for a specific pte.
2227  * @mm: pointer to the process mm_struct
2228  * @addr: virtual address in the process address space
2229  * @pte: pointer to the page table entry
2230  * @bits: bits from the pgste that caused the notify call
2231  *
2232  * This function is assumed to be called with the page table lock held
2233  * for the pte to notify.
2234  */
2235 void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
2236                  pte_t *pte, unsigned long bits)
2237 {
2238         unsigned long offset, gaddr = 0;
2239         unsigned long *table;
2240         struct gmap *gmap, *sg, *next;
2241 
2242         offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
2243         offset = offset * (PAGE_SIZE / sizeof(pte_t));
2244         rcu_read_lock();
2245         list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2246                 spin_lock(&gmap->guest_table_lock);
2247                 table = radix_tree_lookup(&gmap->host_to_guest,
2248                                           vmaddr >> PMD_SHIFT);
2249                 if (table)
2250                         gaddr = __gmap_segment_gaddr(table) + offset;
2251                 spin_unlock(&gmap->guest_table_lock);
2252                 if (!table)
2253                         continue;
2254 
2255                 if (!list_empty(&gmap->children) && (bits & PGSTE_VSIE_BIT)) {
2256                         spin_lock(&gmap->shadow_lock);
2257                         list_for_each_entry_safe(sg, next,
2258                                                  &gmap->children, list)
2259                                 gmap_shadow_notify(sg, vmaddr, gaddr);
2260                         spin_unlock(&gmap->shadow_lock);
2261                 }
2262                 if (bits & PGSTE_IN_BIT)
2263                         gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
2264         }
2265         rcu_read_unlock();
2266 }
2267 EXPORT_SYMBOL_GPL(ptep_notify);
2268 
2269 static void pmdp_notify_gmap(struct gmap *gmap, pmd_t *pmdp,
2270                              unsigned long gaddr)
2271 {
2272         pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_IN;
2273         gmap_call_notifier(gmap, gaddr, gaddr + HPAGE_SIZE - 1);
2274 }
2275 
2276 /**
2277  * gmap_pmdp_xchg - exchange a gmap pmd with another
2278  * @gmap: pointer to the guest address space structure
2279  * @pmdp: pointer to the pmd entry
2280  * @new: replacement entry
2281  * @gaddr: the affected guest address
2282  *
2283  * This function is assumed to be called with the guest_table_lock
2284  * held.
2285  */
2286 static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *pmdp, pmd_t new,
2287                            unsigned long gaddr)
2288 {
2289         gaddr &= HPAGE_MASK;
2290         pmdp_notify_gmap(gmap, pmdp, gaddr);
2291         pmd_val(new) &= ~_SEGMENT_ENTRY_GMAP_IN;
2292         if (MACHINE_HAS_TLB_GUEST)
2293                 __pmdp_idte(gaddr, (pmd_t *)pmdp, IDTE_GUEST_ASCE, gmap->asce,
2294                             IDTE_GLOBAL);
2295         else if (MACHINE_HAS_IDTE)
2296                 __pmdp_idte(gaddr, (pmd_t *)pmdp, 0, 0, IDTE_GLOBAL);
2297         else
2298                 __pmdp_csp(pmdp);
2299         *pmdp = new;
2300 }
2301 
2302 static void gmap_pmdp_clear(struct mm_struct *mm, unsigned long vmaddr,
2303                             int purge)
2304 {
2305         pmd_t *pmdp;
2306         struct gmap *gmap;
2307         unsigned long gaddr;
2308 
2309         rcu_read_lock();
2310         list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2311                 spin_lock(&gmap->guest_table_lock);
2312                 pmdp = (pmd_t *)radix_tree_delete(&gmap->host_to_guest,
2313                                                   vmaddr >> PMD_SHIFT);
2314                 if (pmdp) {
2315                         gaddr = __gmap_segment_gaddr((unsigned long *)pmdp);
2316                         pmdp_notify_gmap(gmap, pmdp, gaddr);
2317                         WARN_ON(pmd_val(*pmdp) & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2318                                                    _SEGMENT_ENTRY_GMAP_UC));
2319                         if (purge)
2320                                 __pmdp_csp(pmdp);
2321                         pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
2322                 }
2323                 spin_unlock(&gmap->guest_table_lock);
2324         }
2325         rcu_read_unlock();
2326 }
2327 
2328 /**
2329  * gmap_pmdp_invalidate - invalidate all affected guest pmd entries without
2330  *                        flushing
2331  * @mm: pointer to the process mm_struct
2332  * @vmaddr: virtual address in the process address space
2333  */
2334 void gmap_pmdp_invalidate(struct mm_struct *mm, unsigned long vmaddr)
2335 {
2336         gmap_pmdp_clear(mm, vmaddr, 0);
2337 }
2338 EXPORT_SYMBOL_GPL(gmap_pmdp_invalidate);
2339 
2340 /**
2341  * gmap_pmdp_csp - csp all affected guest pmd entries
2342  * @mm: pointer to the process mm_struct
2343  * @vmaddr: virtual address in the process address space
2344  */
2345 void gmap_pmdp_csp(struct mm_struct *mm, unsigned long vmaddr)
2346 {
2347         gmap_pmdp_clear(mm, vmaddr, 1);
2348 }
2349 EXPORT_SYMBOL_GPL(gmap_pmdp_csp);
2350 
2351 /**
2352  * gmap_pmdp_idte_local - invalidate and clear a guest pmd entry
2353  * @mm: pointer to the process mm_struct
2354  * @vmaddr: virtual address in the process address space
2355  */
2356 void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr)
2357 {
2358         unsigned long *entry, gaddr;
2359         struct gmap *gmap;
2360         pmd_t *pmdp;
2361 
2362         rcu_read_lock();
2363         list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2364                 spin_lock(&gmap->guest_table_lock);
2365                 entry = radix_tree_delete(&gmap->host_to_guest,
2366                                           vmaddr >> PMD_SHIFT);
2367                 if (entry) {
2368                         pmdp = (pmd_t *)entry;
2369                         gaddr = __gmap_segment_gaddr(entry);
2370                         pmdp_notify_gmap(gmap, pmdp, gaddr);
2371                         WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2372                                            _SEGMENT_ENTRY_GMAP_UC));
2373                         if (MACHINE_HAS_TLB_GUEST)
2374                                 __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
2375                                             gmap->asce, IDTE_LOCAL);
2376                         else if (MACHINE_HAS_IDTE)
2377                                 __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_LOCAL);
2378                         *entry = _SEGMENT_ENTRY_EMPTY;
2379                 }
2380                 spin_unlock(&gmap->guest_table_lock);
2381         }
2382         rcu_read_unlock();
2383 }
2384 EXPORT_SYMBOL_GPL(gmap_pmdp_idte_local);
2385 
2386 /**
2387  * gmap_pmdp_idte_global - invalidate and clear a guest pmd entry
2388  * @mm: pointer to the process mm_struct
2389  * @vmaddr: virtual address in the process address space
2390  */
2391 void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr)
2392 {
2393         unsigned long *entry, gaddr;
2394         struct gmap *gmap;
2395         pmd_t *pmdp;
2396 
2397         rcu_read_lock();
2398         list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2399                 spin_lock(&gmap->guest_table_lock);
2400                 entry = radix_tree_delete(&gmap->host_to_guest,
2401                                           vmaddr >> PMD_SHIFT);
2402                 if (entry) {
2403                         pmdp = (pmd_t *)entry;
2404                         gaddr = __gmap_segment_gaddr(entry);
2405                         pmdp_notify_gmap(gmap, pmdp, gaddr);
2406                         WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2407                                            _SEGMENT_ENTRY_GMAP_UC));
2408                         if (MACHINE_HAS_TLB_GUEST)
2409                                 __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
2410                                             gmap->asce, IDTE_GLOBAL);
2411                         else if (MACHINE_HAS_IDTE)
2412                                 __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_GLOBAL);
2413                         else
2414                                 __pmdp_csp(pmdp);
2415                         *entry = _SEGMENT_ENTRY_EMPTY;
2416                 }
2417                 spin_unlock(&gmap->guest_table_lock);
2418         }
2419         rcu_read_unlock();
2420 }
2421 EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global);
2422 
2423 /**
2424  * gmap_test_and_clear_dirty_pmd - test and reset segment dirty status
2425  * @gmap: pointer to guest address space
2426  * @pmdp: pointer to the pmd to be tested
2427  * @gaddr: virtual address in the guest address space
2428  *
2429  * This function is assumed to be called with the guest_table_lock
2430  * held.
2431  */
2432 static bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp,
2433                                           unsigned long gaddr)
2434 {
2435         if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
2436                 return false;
2437 
2438         /* Already protected memory, which did not change is clean */
2439         if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT &&
2440             !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC))
2441                 return false;
2442 
2443         /* Clear UC indication and reset protection */
2444         pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_UC;
2445         gmap_protect_pmd(gmap, gaddr, pmdp, PROT_READ, 0);
2446         return true;
2447 }
2448 
2449 /**
2450  * gmap_sync_dirty_log_pmd - set bitmap based on dirty status of segment
2451  * @gmap: pointer to guest address space
2452  * @bitmap: dirty bitmap for this pmd
2453  * @gaddr: virtual address in the guest address space
2454  * @vmaddr: virtual address in the host address space
2455  *
2456  * This function is assumed to be called with the guest_table_lock
2457  * held.
2458  */
2459 void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4],
2460                              unsigned long gaddr, unsigned long vmaddr)
2461 {
2462         int i;
2463         pmd_t *pmdp;
2464         pte_t *ptep;
2465         spinlock_t *ptl;
2466 
2467         pmdp = gmap_pmd_op_walk(gmap, gaddr);
2468         if (!pmdp)
2469                 return;
2470 
2471         if (pmd_large(*pmdp)) {
2472                 if (gmap_test_and_clear_dirty_pmd(gmap, pmdp, gaddr))
2473                         bitmap_fill(bitmap, _PAGE_ENTRIES);
2474         } else {
2475                 for (i = 0; i < _PAGE_ENTRIES; i++, vmaddr += PAGE_SIZE) {
2476                         ptep = pte_alloc_map_lock(gmap->mm, pmdp, vmaddr, &ptl);
2477                         if (!ptep)
2478                                 continue;
2479                         if (ptep_test_and_clear_uc(gmap->mm, vmaddr, ptep))
2480                                 set_bit(i, bitmap);
2481                         spin_unlock(ptl);
2482                 }
2483         }
2484         gmap_pmd_op_end(gmap, pmdp);
2485 }
2486 EXPORT_SYMBOL_GPL(gmap_sync_dirty_log_pmd);
2487 
2488 static inline void thp_split_mm(struct mm_struct *mm)
2489 {
2490 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2491         struct vm_area_struct *vma;
2492         unsigned long addr;
2493 
2494         for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
2495                 for (addr = vma->vm_start;
2496                      addr < vma->vm_end;
2497                      addr += PAGE_SIZE)
2498                         follow_page(vma, addr, FOLL_SPLIT);
2499                 vma->vm_flags &= ~VM_HUGEPAGE;
2500                 vma->vm_flags |= VM_NOHUGEPAGE;
2501         }
2502         mm->def_flags |= VM_NOHUGEPAGE;
2503 #endif
2504 }
2505 
2506 /*
2507  * Remove all empty zero pages from the mapping for lazy refaulting
2508  * - This must be called after mm->context.has_pgste is set, to avoid
2509  *   future creation of zero pages
2510  * - This must be called after THP was enabled
2511  */
2512 static int __zap_zero_pages(pmd_t *pmd, unsigned long start,
2513                            unsigned long end, struct mm_walk *walk)
2514 {
2515         unsigned long addr;
2516 
2517         for (addr = start; addr != end; addr += PAGE_SIZE) {
2518                 pte_t *ptep;
2519                 spinlock_t *ptl;
2520 
2521                 ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
2522                 if (is_zero_pfn(pte_pfn(*ptep)))
2523                         ptep_xchg_direct(walk->mm, addr, ptep, __pte(_PAGE_INVALID));
2524                 pte_unmap_unlock(ptep, ptl);
2525         }
2526         return 0;
2527 }
2528 
2529 static const struct mm_walk_ops zap_zero_walk_ops = {
2530         .pmd_entry      = __zap_zero_pages,
2531 };
2532 
2533 /*
2534  * switch on pgstes for its userspace process (for kvm)
2535  */
2536 int s390_enable_sie(void)
2537 {
2538         struct mm_struct *mm = current->mm;
2539 
2540         /* Do we have pgstes? if yes, we are done */
2541         if (mm_has_pgste(mm))
2542                 return 0;
2543         /* Fail if the page tables are 2K */
2544         if (!mm_alloc_pgste(mm))
2545                 return -EINVAL;
2546         down_write(&mm->mmap_sem);
2547         mm->context.has_pgste = 1;
2548         /* split thp mappings and disable thp for future mappings */
2549         thp_split_mm(mm);
2550         walk_page_range(mm, 0, TASK_SIZE, &zap_zero_walk_ops, NULL);
2551         up_write(&mm->mmap_sem);
2552         return 0;
2553 }
2554 EXPORT_SYMBOL_GPL(s390_enable_sie);
2555 
2556 /*
2557  * Enable storage key handling from now on and initialize the storage
2558  * keys with the default key.
2559  */
2560 static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
2561                                   unsigned long next, struct mm_walk *walk)
2562 {
2563         /* Clear storage key */
2564         ptep_zap_key(walk->mm, addr, pte);
2565         return 0;
2566 }
2567 
2568 static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
2569                                       unsigned long hmask, unsigned long next,
2570                                       struct mm_walk *walk)
2571 {
2572         pmd_t *pmd = (pmd_t *)pte;
2573         unsigned long start, end;
2574         struct page *page = pmd_page(*pmd);
2575 
2576         /*
2577          * The write check makes sure we do not set a key on shared
2578          * memory. This is needed as the walker does not differentiate
2579          * between actual guest memory and the process executable or
2580          * shared libraries.
2581          */
2582         if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID ||
2583             !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE))
2584                 return 0;
2585 
2586         start = pmd_val(*pmd) & HPAGE_MASK;
2587         end = start + HPAGE_SIZE - 1;
2588         __storage_key_init_range(start, end);
2589         set_bit(PG_arch_1, &page->flags);
2590         return 0;
2591 }
2592 
2593 static const struct mm_walk_ops enable_skey_walk_ops = {
2594         .hugetlb_entry          = __s390_enable_skey_hugetlb,
2595         .pte_entry              = __s390_enable_skey_pte,
2596 };
2597 
2598 int s390_enable_skey(void)
2599 {
2600         struct mm_struct *mm = current->mm;
2601         struct vm_area_struct *vma;
2602         int rc = 0;
2603 
2604         down_write(&mm->mmap_sem);
2605         if (mm_uses_skeys(mm))
2606                 goto out_up;
2607 
2608         mm->context.uses_skeys = 1;
2609         for (vma = mm->mmap; vma; vma = vma->vm_next) {
2610                 if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
2611                                 MADV_UNMERGEABLE, &vma->vm_flags)) {
2612                         mm->context.uses_skeys = 0;
2613                         rc = -ENOMEM;
2614                         goto out_up;
2615                 }
2616         }
2617         mm->def_flags &= ~VM_MERGEABLE;
2618 
2619         walk_page_range(mm, 0, TASK_SIZE, &enable_skey_walk_ops, NULL);
2620 
2621 out_up:
2622         up_write(&mm->mmap_sem);
2623         return rc;
2624 }
2625 EXPORT_SYMBOL_GPL(s390_enable_skey);
2626 
2627 /*
2628  * Reset CMMA state, make all pages stable again.
2629  */
2630 static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
2631                              unsigned long next, struct mm_walk *walk)
2632 {
2633         ptep_zap_unused(walk->mm, addr, pte, 1);
2634         return 0;
2635 }
2636 
2637 static const struct mm_walk_ops reset_cmma_walk_ops = {
2638         .pte_entry              = __s390_reset_cmma,
2639 };
2640 
2641 void s390_reset_cmma(struct mm_struct *mm)
2642 {
2643         down_write(&mm->mmap_sem);
2644         walk_page_range(mm, 0, TASK_SIZE, &reset_cmma_walk_ops, NULL);
2645         up_write(&mm->mmap_sem);
2646 }
2647 EXPORT_SYMBOL_GPL(s390_reset_cmma);