drivers/vfio/vfio_iommu_spapr_tce.c

   1 /*
   2  * VFIO: IOMMU DMA mapping support for TCE on POWER
   3  *
   4  * Copyright (C) 2013 IBM Corp.  All rights reserved.
   5  *     Author: Alexey Kardashevskiy <aik@ozlabs.ru>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * Derived from original vfio_iommu_type1.c:
  12  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
  13  *     Author: Alex Williamson <alex.williamson@redhat.com>
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/pci.h>
  18 #include <linux/slab.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/err.h>
  21 #include <linux/vfio.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/sched/mm.h>
  24 #include <linux/sched/signal.h>
  25
  26 #include <asm/iommu.h>
  27 #include <asm/tce.h>
  28 #include <asm/mmu_context.h>
  29
  30 #define DRIVER_VERSION  "0.1"
  31 #define DRIVER_AUTHOR   "aik@ozlabs.ru"
  32 #define DRIVER_DESC     "VFIO IOMMU SPAPR TCE"
  33
  34 static void tce_iommu_detach_group(void *iommu_data,
  35                 struct iommu_group *iommu_group);
  36
  37 static long try_increment_locked_vm(struct mm_struct *mm, long npages)
  38 {
  39         long ret = 0, locked, lock_limit;
  40
  41         if (WARN_ON_ONCE(!mm))
  42                 return -EPERM;
  43
  44         if (!npages)
  45                 return 0;
  46
  47         down_write(&mm->mmap_sem);
  48         locked = mm->locked_vm + npages;
  49         lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  50         if (locked > lock_limit && !capable(CAP_IPC_LOCK))
  51                 ret = -ENOMEM;
  52         else
  53                 mm->locked_vm += npages;
  54
  55         pr_debug("[%d] RLIMIT_MEMLOCK +%ld %ld/%ld%s\n", current->pid,
  56                         npages << PAGE_SHIFT,
  57                         mm->locked_vm << PAGE_SHIFT,
  58                         rlimit(RLIMIT_MEMLOCK),
  59                         ret ? " - exceeded" : "");
  60
  61         up_write(&mm->mmap_sem);
  62
  63         return ret;
  64 }
  65
  66 static void decrement_locked_vm(struct mm_struct *mm, long npages)
  67 {
  68         if (!mm || !npages)
  69                 return;
  70
  71         down_write(&mm->mmap_sem);
  72         if (WARN_ON_ONCE(npages > mm->locked_vm))
  73                 npages = mm->locked_vm;
  74         mm->locked_vm -= npages;
  75         pr_debug("[%d] RLIMIT_MEMLOCK -%ld %ld/%ld\n", current->pid,
  76                         npages << PAGE_SHIFT,
  77                         mm->locked_vm << PAGE_SHIFT,
  78                         rlimit(RLIMIT_MEMLOCK));
  79         up_write(&mm->mmap_sem);
  80 }
  81
  82 /*
  83  * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
  84  *
  85  * This code handles mapping and unmapping of user data buffers
  86  * into DMA'ble space using the IOMMU
  87  */
  88
  89 struct tce_iommu_group {
  90         struct list_head next;
  91         struct iommu_group *grp;
  92 };
  93
  94 /*
  95  * A container needs to remember which preregistered region  it has
  96  * referenced to do proper cleanup at the userspace process exit.
  97  */
  98 struct tce_iommu_prereg {
  99         struct list_head next;
 100         struct mm_iommu_table_group_mem_t *mem;
 101 };
 102
 103 /*
 104  * The container descriptor supports only a single group per container.
 105  * Required by the API as the container is not supplied with the IOMMU group
 106  * at the moment of initialization.
 107  */
 108 struct tce_container {
 109         struct mutex lock;
 110         bool enabled;
 111         bool v2;
 112         bool def_window_pending;
 113         unsigned long locked_pages;
 114         struct mm_struct *mm;
 115         struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
 116         struct list_head group_list;
 117         struct list_head prereg_list;
 118 };
 119
 120 static long tce_iommu_mm_set(struct tce_container *container)
 121 {
 122         if (container->mm) {
 123                 if (container->mm == current->mm)
 124                         return 0;
 125                 return -EPERM;
 126         }
 127         BUG_ON(!current->mm);
 128         container->mm = current->mm;
 129         atomic_inc(&container->mm->mm_count);
 130
 131         return 0;
 132 }
 133
 134 static long tce_iommu_prereg_free(struct tce_container *container,
 135                 struct tce_iommu_prereg *tcemem)
 136 {
 137         long ret;
 138
 139         ret = mm_iommu_put(container->mm, tcemem->mem);
 140         if (ret)
 141                 return ret;
 142
 143         list_del(&tcemem->next);
 144         kfree(tcemem);
 145
 146         return 0;
 147 }
 148
 149 static long tce_iommu_unregister_pages(struct tce_container *container,
 150                 __u64 vaddr, __u64 size)
 151 {
 152         struct mm_iommu_table_group_mem_t *mem;
 153         struct tce_iommu_prereg *tcemem;
 154         bool found = false;
 155
 156         if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
 157                 return -EINVAL;
 158
 159         mem = mm_iommu_find(container->mm, vaddr, size >> PAGE_SHIFT);
 160         if (!mem)
 161                 return -ENOENT;
 162
 163         list_for_each_entry(tcemem, &container->prereg_list, next) {
 164                 if (tcemem->mem == mem) {
 165                         found = true;
 166                         break;
 167                 }
 168         }
 169
 170         if (!found)
 171                 return -ENOENT;
 172
 173         return tce_iommu_prereg_free(container, tcemem);
 174 }
 175
 176 static long tce_iommu_register_pages(struct tce_container *container,
 177                 __u64 vaddr, __u64 size)
 178 {
 179         long ret = 0;
 180         struct mm_iommu_table_group_mem_t *mem = NULL;
 181         struct tce_iommu_prereg *tcemem;
 182         unsigned long entries = size >> PAGE_SHIFT;
 183
 184         if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
 185                         ((vaddr + size) < vaddr))
 186                 return -EINVAL;
 187
 188         mem = mm_iommu_find(container->mm, vaddr, entries);
 189         if (mem) {
 190                 list_for_each_entry(tcemem, &container->prereg_list, next) {
 191                         if (tcemem->mem == mem)
 192                                 return -EBUSY;
 193                 }
 194         }
 195
 196         ret = mm_iommu_get(container->mm, vaddr, entries, &mem);
 197         if (ret)
 198                 return ret;
 199
 200         tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
 201         if (!tcemem) {
 202                 mm_iommu_put(container->mm, mem);
 203                 return -ENOMEM;
 204         }
 205
 206         tcemem->mem = mem;
 207         list_add(&tcemem->next, &container->prereg_list);
 208
 209         container->enabled = true;
 210
 211         return 0;
 212 }
 213
 214 static bool tce_page_is_contained(struct page *page, unsigned page_shift)
 215 {
 216         /*
 217          * Check that the TCE table granularity is not bigger than the size of
 218          * a page we just found. Otherwise the hardware can get access to
 219          * a bigger memory chunk that it should.
 220          */
 221         return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
 222 }
 223
 224 static inline bool tce_groups_attached(struct tce_container *container)
 225 {
 226         return !list_empty(&container->group_list);
 227 }
 228
 229 static long tce_iommu_find_table(struct tce_container *container,
 230                 phys_addr_t ioba, struct iommu_table **ptbl)
 231 {
 232         long i;
 233
 234         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 235                 struct iommu_table *tbl = container->tables[i];
 236
 237                 if (tbl) {
 238                         unsigned long entry = ioba >> tbl->it_page_shift;
 239                         unsigned long start = tbl->it_offset;
 240                         unsigned long end = start + tbl->it_size;
 241
 242                         if ((start <= entry) && (entry < end)) {
 243                                 *ptbl = tbl;
 244                                 return i;
 245                         }
 246                 }
 247         }
 248
 249         return -1;
 250 }
 251
 252 static int tce_iommu_find_free_table(struct tce_container *container)
 253 {
 254         int i;
 255
 256         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 257                 if (!container->tables[i])
 258                         return i;
 259         }
 260
 261         return -ENOSPC;
 262 }
 263
 264 static int tce_iommu_enable(struct tce_container *container)
 265 {
 266         int ret = 0;
 267         unsigned long locked;
 268         struct iommu_table_group *table_group;
 269         struct tce_iommu_group *tcegrp;
 270
 271         if (container->enabled)
 272                 return -EBUSY;
 273
 274         /*
 275          * When userspace pages are mapped into the IOMMU, they are effectively
 276          * locked memory, so, theoretically, we need to update the accounting
 277          * of locked pages on each map and unmap.  For powerpc, the map unmap
 278          * paths can be very hot, though, and the accounting would kill
 279          * performance, especially since it would be difficult to impossible
 280          * to handle the accounting in real mode only.
 281          *
 282          * To address that, rather than precisely accounting every page, we
 283          * instead account for a worst case on locked memory when the iommu is
 284          * enabled and disabled.  The worst case upper bound on locked memory
 285          * is the size of the whole iommu window, which is usually relatively
 286          * small (compared to total memory sizes) on POWER hardware.
 287          *
 288          * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
 289          * that would effectively kill the guest at random points, much better
 290          * enforcing the limit based on the max that the guest can map.
 291          *
 292          * Unfortunately at the moment it counts whole tables, no matter how
 293          * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
 294          * each with 2GB DMA window, 8GB will be counted here. The reason for
 295          * this is that we cannot tell here the amount of RAM used by the guest
 296          * as this information is only available from KVM and VFIO is
 297          * KVM agnostic.
 298          *
 299          * So we do not allow enabling a container without a group attached
 300          * as there is no way to know how much we should increment
 301          * the locked_vm counter.
 302          */
 303         if (!tce_groups_attached(container))
 304                 return -ENODEV;
 305
 306         tcegrp = list_first_entry(&container->group_list,
 307                         struct tce_iommu_group, next);
 308         table_group = iommu_group_get_iommudata(tcegrp->grp);
 309         if (!table_group)
 310                 return -ENODEV;
 311
 312         if (!table_group->tce32_size)
 313                 return -EPERM;
 314
 315         ret = tce_iommu_mm_set(container);
 316         if (ret)
 317                 return ret;
 318
 319         locked = table_group->tce32_size >> PAGE_SHIFT;
 320         ret = try_increment_locked_vm(container->mm, locked);
 321         if (ret)
 322                 return ret;
 323
 324         container->locked_pages = locked;
 325
 326         container->enabled = true;
 327
 328         return ret;
 329 }
 330
 331 static void tce_iommu_disable(struct tce_container *container)
 332 {
 333         if (!container->enabled)
 334                 return;
 335
 336         container->enabled = false;
 337
 338         BUG_ON(!container->mm);
 339         decrement_locked_vm(container->mm, container->locked_pages);
 340 }
 341
 342 static void *tce_iommu_open(unsigned long arg)
 343 {
 344         struct tce_container *container;
 345
 346         if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
 347                 pr_err("tce_vfio: Wrong IOMMU type\n");
 348                 return ERR_PTR(-EINVAL);
 349         }
 350
 351         container = kzalloc(sizeof(*container), GFP_KERNEL);
 352         if (!container)
 353                 return ERR_PTR(-ENOMEM);
 354
 355         mutex_init(&container->lock);
 356         INIT_LIST_HEAD_RCU(&container->group_list);
 357         INIT_LIST_HEAD_RCU(&container->prereg_list);
 358
 359         container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
 360
 361         return container;
 362 }
 363
 364 static int tce_iommu_clear(struct tce_container *container,
 365                 struct iommu_table *tbl,
 366                 unsigned long entry, unsigned long pages);
 367 static void tce_iommu_free_table(struct tce_container *container,
 368                 struct iommu_table *tbl);
 369
 370 static void tce_iommu_release(void *iommu_data)
 371 {
 372         struct tce_container *container = iommu_data;
 373         struct tce_iommu_group *tcegrp;
 374         long i;
 375
 376         while (tce_groups_attached(container)) {
 377                 tcegrp = list_first_entry(&container->group_list,
 378                                 struct tce_iommu_group, next);
 379                 tce_iommu_detach_group(iommu_data, tcegrp->grp);
 380         }
 381
 382         /*
 383          * If VFIO created a table, it was not disposed
 384          * by tce_iommu_detach_group() so do it now.
 385          */
 386         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 387                 struct iommu_table *tbl = container->tables[i];
 388
 389                 if (!tbl)
 390                         continue;
 391
 392                 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
 393                 tce_iommu_free_table(container, tbl);
 394         }
 395
 396         while (!list_empty(&container->prereg_list)) {
 397                 struct tce_iommu_prereg *tcemem;
 398
 399                 tcemem = list_first_entry(&container->prereg_list,
 400                                 struct tce_iommu_prereg, next);
 401                 WARN_ON_ONCE(tce_iommu_prereg_free(container, tcemem));
 402         }
 403
 404         tce_iommu_disable(container);
 405         if (container->mm)
 406                 mmdrop(container->mm);
 407         mutex_destroy(&container->lock);
 408
 409         kfree(container);
 410 }
 411
 412 static void tce_iommu_unuse_page(struct tce_container *container,
 413                 unsigned long hpa)
 414 {
 415         struct page *page;
 416
 417         page = pfn_to_page(hpa >> PAGE_SHIFT);
 418         put_page(page);
 419 }
 420
 421 static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
 422                 unsigned long tce, unsigned long shift,
 423                 unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
 424 {
 425         long ret = 0;
 426         struct mm_iommu_table_group_mem_t *mem;
 427
 428         mem = mm_iommu_lookup(container->mm, tce, 1ULL << shift);
 429         if (!mem)
 430                 return -EINVAL;
 431
 432         ret = mm_iommu_ua_to_hpa(mem, tce, shift, phpa);
 433         if (ret)
 434                 return -EINVAL;
 435
 436         *pmem = mem;
 437
 438         return 0;
 439 }
 440
 441 static void tce_iommu_unuse_page_v2(struct tce_container *container,
 442                 struct iommu_table *tbl, unsigned long entry)
 443 {
 444         struct mm_iommu_table_group_mem_t *mem = NULL;
 445         int ret;
 446         unsigned long hpa = 0;
 447         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
 448
 449         if (!pua)
 450                 return;
 451
 452         ret = tce_iommu_prereg_ua_to_hpa(container, be64_to_cpu(*pua),
 453                         tbl->it_page_shift, &hpa, &mem);
 454         if (ret)
 455                 pr_debug("%s: tce %llx at #%lx was not cached, ret=%d\n",
 456                                 __func__, be64_to_cpu(*pua), entry, ret);
 457         if (mem)
 458                 mm_iommu_mapped_dec(mem);
 459
 460         *pua = cpu_to_be64(0);
 461 }
 462
 463 static int tce_iommu_clear(struct tce_container *container,
 464                 struct iommu_table *tbl,
 465                 unsigned long entry, unsigned long pages)
 466 {
 467         unsigned long oldhpa;
 468         long ret;
 469         enum dma_data_direction direction;
 470         unsigned long lastentry = entry + pages;
 471
 472         for ( ; entry < lastentry; ++entry) {
 473                 if (tbl->it_indirect_levels && tbl->it_userspace) {
 474                         /*
 475                          * For multilevel tables, we can take a shortcut here
 476                          * and skip some TCEs as we know that the userspace
 477                          * addresses cache is a mirror of the real TCE table
 478                          * and if it is missing some indirect levels, then
 479                          * the hardware table does not have them allocated
 480                          * either and therefore does not require updating.
 481                          */
 482                         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl,
 483                                         entry);
 484                         if (!pua) {
 485                                 /* align to level_size which is power of two */
 486                                 entry |= tbl->it_level_size - 1;
 487                                 continue;
 488                         }
 489                 }
 490
 491                 cond_resched();
 492
 493                 direction = DMA_NONE;
 494                 oldhpa = 0;
 495                 ret = iommu_tce_xchg(tbl, entry, &oldhpa, &direction);
 496                 if (ret)
 497                         continue;
 498
 499                 if (direction == DMA_NONE)
 500                         continue;
 501
 502                 if (container->v2) {
 503                         tce_iommu_unuse_page_v2(container, tbl, entry);
 504                         continue;
 505                 }
 506
 507                 tce_iommu_unuse_page(container, oldhpa);
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
 514 {
 515         struct page *page = NULL;
 516         enum dma_data_direction direction = iommu_tce_direction(tce);
 517
 518         if (get_user_pages_fast(tce & PAGE_MASK, 1,
 519                         direction != DMA_TO_DEVICE, &page) != 1)
 520                 return -EFAULT;
 521
 522         *hpa = __pa((unsigned long) page_address(page));
 523
 524         return 0;
 525 }
 526
 527 static long tce_iommu_build(struct tce_container *container,
 528                 struct iommu_table *tbl,
 529                 unsigned long entry, unsigned long tce, unsigned long pages,
 530                 enum dma_data_direction direction)
 531 {
 532         long i, ret = 0;
 533         struct page *page;
 534         unsigned long hpa;
 535         enum dma_data_direction dirtmp;
 536
 537         for (i = 0; i < pages; ++i) {
 538                 unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
 539
 540                 ret = tce_iommu_use_page(tce, &hpa);
 541                 if (ret)
 542                         break;
 543
 544                 page = pfn_to_page(hpa >> PAGE_SHIFT);
 545                 if (!tce_page_is_contained(page, tbl->it_page_shift)) {
 546                         ret = -EPERM;
 547                         break;
 548                 }
 549
 550                 hpa |= offset;
 551                 dirtmp = direction;
 552                 ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp);
 553                 if (ret) {
 554                         tce_iommu_unuse_page(container, hpa);
 555                         pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
 556                                         __func__, entry << tbl->it_page_shift,
 557                                         tce, ret);
 558                         break;
 559                 }
 560
 561                 if (dirtmp != DMA_NONE)
 562                         tce_iommu_unuse_page(container, hpa);
 563
 564                 tce += IOMMU_PAGE_SIZE(tbl);
 565         }
 566
 567         if (ret)
 568                 tce_iommu_clear(container, tbl, entry, i);
 569
 570         return ret;
 571 }
 572
 573 static long tce_iommu_build_v2(struct tce_container *container,
 574                 struct iommu_table *tbl,
 575                 unsigned long entry, unsigned long tce, unsigned long pages,
 576                 enum dma_data_direction direction)
 577 {
 578         long i, ret = 0;
 579         struct page *page;
 580         unsigned long hpa;
 581         enum dma_data_direction dirtmp;
 582
 583         for (i = 0; i < pages; ++i) {
 584                 struct mm_iommu_table_group_mem_t *mem = NULL;
 585                 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i);
 586
 587                 ret = tce_iommu_prereg_ua_to_hpa(container,
 588                                 tce, tbl->it_page_shift, &hpa, &mem);
 589                 if (ret)
 590                         break;
 591
 592                 page = pfn_to_page(hpa >> PAGE_SHIFT);
 593                 if (!tce_page_is_contained(page, tbl->it_page_shift)) {
 594                         ret = -EPERM;
 595                         break;
 596                 }
 597
 598                 /* Preserve offset within IOMMU page */
 599                 hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
 600                 dirtmp = direction;
 601
 602                 /* The registered region is being unregistered */
 603                 if (mm_iommu_mapped_inc(mem))
 604                         break;
 605
 606                 ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp);
 607                 if (ret) {
 608                         /* dirtmp cannot be DMA_NONE here */
 609                         tce_iommu_unuse_page_v2(container, tbl, entry + i);
 610                         pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
 611                                         __func__, entry << tbl->it_page_shift,
 612                                         tce, ret);
 613                         break;
 614                 }
 615
 616                 if (dirtmp != DMA_NONE)
 617                         tce_iommu_unuse_page_v2(container, tbl, entry + i);
 618
 619                 *pua = cpu_to_be64(tce);
 620
 621                 tce += IOMMU_PAGE_SIZE(tbl);
 622         }
 623
 624         if (ret)
 625                 tce_iommu_clear(container, tbl, entry, i);
 626
 627         return ret;
 628 }
 629
 630 static long tce_iommu_create_table(struct tce_container *container,
 631                         struct iommu_table_group *table_group,
 632                         int num,
 633                         __u32 page_shift,
 634                         __u64 window_size,
 635                         __u32 levels,
 636                         struct iommu_table **ptbl)
 637 {
 638         long ret, table_size;
 639
 640         table_size = table_group->ops->get_table_size(page_shift, window_size,
 641                         levels);
 642         if (!table_size)
 643                 return -EINVAL;
 644
 645         ret = try_increment_locked_vm(container->mm, table_size >> PAGE_SHIFT);
 646         if (ret)
 647                 return ret;
 648
 649         ret = table_group->ops->create_table(table_group, num,
 650                         page_shift, window_size, levels, ptbl);
 651
 652         WARN_ON(!ret && !(*ptbl)->it_ops->free);
 653         WARN_ON(!ret && ((*ptbl)->it_allocated_size > table_size));
 654
 655         return ret;
 656 }
 657
 658 static void tce_iommu_free_table(struct tce_container *container,
 659                 struct iommu_table *tbl)
 660 {
 661         unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
 662
 663         iommu_tce_table_put(tbl);
 664         decrement_locked_vm(container->mm, pages);
 665 }
 666
 667 static long tce_iommu_create_window(struct tce_container *container,
 668                 __u32 page_shift, __u64 window_size, __u32 levels,
 669                 __u64 *start_addr)
 670 {
 671         struct tce_iommu_group *tcegrp;
 672         struct iommu_table_group *table_group;
 673         struct iommu_table *tbl = NULL;
 674         long ret, num;
 675
 676         num = tce_iommu_find_free_table(container);
 677         if (num < 0)
 678                 return num;
 679
 680         /* Get the first group for ops::create_table */
 681         tcegrp = list_first_entry(&container->group_list,
 682                         struct tce_iommu_group, next);
 683         table_group = iommu_group_get_iommudata(tcegrp->grp);
 684         if (!table_group)
 685                 return -EFAULT;
 686
 687         if (!(table_group->pgsizes & (1ULL << page_shift)))
 688                 return -EINVAL;
 689
 690         if (!table_group->ops->set_window || !table_group->ops->unset_window ||
 691                         !table_group->ops->get_table_size ||
 692                         !table_group->ops->create_table)
 693                 return -EPERM;
 694
 695         /* Create TCE table */
 696         ret = tce_iommu_create_table(container, table_group, num,
 697                         page_shift, window_size, levels, &tbl);
 698         if (ret)
 699                 return ret;
 700
 701         BUG_ON(!tbl->it_ops->free);
 702
 703         /*
 704          * Program the table to every group.
 705          * Groups have been tested for compatibility at the attach time.
 706          */
 707         list_for_each_entry(tcegrp, &container->group_list, next) {
 708                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 709
 710                 ret = table_group->ops->set_window(table_group, num, tbl);
 711                 if (ret)
 712                         goto unset_exit;
 713         }
 714
 715         container->tables[num] = tbl;
 716
 717         /* Return start address assigned by platform in create_table() */
 718         *start_addr = tbl->it_offset << tbl->it_page_shift;
 719
 720         return 0;
 721
 722 unset_exit:
 723         list_for_each_entry(tcegrp, &container->group_list, next) {
 724                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 725                 table_group->ops->unset_window(table_group, num);
 726         }
 727         tce_iommu_free_table(container, tbl);
 728
 729         return ret;
 730 }
 731
 732 static long tce_iommu_remove_window(struct tce_container *container,
 733                 __u64 start_addr)
 734 {
 735         struct iommu_table_group *table_group = NULL;
 736         struct iommu_table *tbl;
 737         struct tce_iommu_group *tcegrp;
 738         int num;
 739
 740         num = tce_iommu_find_table(container, start_addr, &tbl);
 741         if (num < 0)
 742                 return -EINVAL;
 743
 744         BUG_ON(!tbl->it_size);
 745
 746         /* Detach groups from IOMMUs */
 747         list_for_each_entry(tcegrp, &container->group_list, next) {
 748                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 749
 750                 /*
 751                  * SPAPR TCE IOMMU exposes the default DMA window to
 752                  * the guest via dma32_window_start/size of
 753                  * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
 754                  * the userspace to remove this window, some do not so
 755                  * here we check for the platform capability.
 756                  */
 757                 if (!table_group->ops || !table_group->ops->unset_window)
 758                         return -EPERM;
 759
 760                 table_group->ops->unset_window(table_group, num);
 761         }
 762
 763         /* Free table */
 764         tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
 765         tce_iommu_free_table(container, tbl);
 766         container->tables[num] = NULL;
 767
 768         return 0;
 769 }
 770
 771 static long tce_iommu_create_default_window(struct tce_container *container)
 772 {
 773         long ret;
 774         __u64 start_addr = 0;
 775         struct tce_iommu_group *tcegrp;
 776         struct iommu_table_group *table_group;
 777
 778         if (!container->def_window_pending)
 779                 return 0;
 780
 781         if (!tce_groups_attached(container))
 782                 return -ENODEV;
 783
 784         tcegrp = list_first_entry(&container->group_list,
 785                         struct tce_iommu_group, next);
 786         table_group = iommu_group_get_iommudata(tcegrp->grp);
 787         if (!table_group)
 788                 return -ENODEV;
 789
 790         ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
 791                         table_group->tce32_size, 1, &start_addr);
 792         WARN_ON_ONCE(!ret && start_addr);
 793
 794         if (!ret)
 795                 container->def_window_pending = false;
 796
 797         return ret;
 798 }
 799
 800 static long tce_iommu_ioctl(void *iommu_data,
 801                                  unsigned int cmd, unsigned long arg)
 802 {
 803         struct tce_container *container = iommu_data;
 804         unsigned long minsz, ddwsz;
 805         long ret;
 806
 807         switch (cmd) {
 808         case VFIO_CHECK_EXTENSION:
 809                 switch (arg) {
 810                 case VFIO_SPAPR_TCE_IOMMU:
 811                 case VFIO_SPAPR_TCE_v2_IOMMU:
 812                         ret = 1;
 813                         break;
 814                 default:
 815                         ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
 816                         break;
 817                 }
 818
 819                 return (ret < 0) ? 0 : ret;
 820         }
 821
 822         /*
 823          * Sanity check to prevent one userspace from manipulating
 824          * another userspace mm.
 825          */
 826         BUG_ON(!container);
 827         if (container->mm && container->mm != current->mm)
 828                 return -EPERM;
 829
 830         switch (cmd) {
 831         case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
 832                 struct vfio_iommu_spapr_tce_info info;
 833                 struct tce_iommu_group *tcegrp;
 834                 struct iommu_table_group *table_group;
 835
 836                 if (!tce_groups_attached(container))
 837                         return -ENXIO;
 838
 839                 tcegrp = list_first_entry(&container->group_list,
 840                                 struct tce_iommu_group, next);
 841                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 842
 843                 if (!table_group)
 844                         return -ENXIO;
 845
 846                 minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
 847                                 dma32_window_size);
 848
 849                 if (copy_from_user(&info, (void __user *)arg, minsz))
 850                         return -EFAULT;
 851
 852                 if (info.argsz < minsz)
 853                         return -EINVAL;
 854
 855                 info.dma32_window_start = table_group->tce32_start;
 856                 info.dma32_window_size = table_group->tce32_size;
 857                 info.flags = 0;
 858                 memset(&info.ddw, 0, sizeof(info.ddw));
 859
 860                 if (table_group->max_dynamic_windows_supported &&
 861                                 container->v2) {
 862                         info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
 863                         info.ddw.pgsizes = table_group->pgsizes;
 864                         info.ddw.max_dynamic_windows_supported =
 865                                 table_group->max_dynamic_windows_supported;
 866                         info.ddw.levels = table_group->max_levels;
 867                 }
 868
 869                 ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
 870
 871                 if (info.argsz >= ddwsz)
 872                         minsz = ddwsz;
 873
 874                 if (copy_to_user((void __user *)arg, &info, minsz))
 875                         return -EFAULT;
 876
 877                 return 0;
 878         }
 879         case VFIO_IOMMU_MAP_DMA: {
 880                 struct vfio_iommu_type1_dma_map param;
 881                 struct iommu_table *tbl = NULL;
 882                 long num;
 883                 enum dma_data_direction direction;
 884
 885                 if (!container->enabled)
 886                         return -EPERM;
 887
 888                 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
 889
 890                 if (copy_from_user(&param, (void __user *)arg, minsz))
 891                         return -EFAULT;
 892
 893                 if (param.argsz < minsz)
 894                         return -EINVAL;
 895
 896                 if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
 897                                 VFIO_DMA_MAP_FLAG_WRITE))
 898                         return -EINVAL;
 899
 900                 ret = tce_iommu_create_default_window(container);
 901                 if (ret)
 902                         return ret;
 903
 904                 num = tce_iommu_find_table(container, param.iova, &tbl);
 905                 if (num < 0)
 906                         return -ENXIO;
 907
 908                 if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
 909                                 (param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
 910                         return -EINVAL;
 911
 912                 /* iova is checked by the IOMMU API */
 913                 if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
 914                         if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
 915                                 direction = DMA_BIDIRECTIONAL;
 916                         else
 917                                 direction = DMA_TO_DEVICE;
 918                 } else {
 919                         if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
 920                                 direction = DMA_FROM_DEVICE;
 921                         else
 922                                 return -EINVAL;
 923                 }
 924
 925                 ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
 926                 if (ret)
 927                         return ret;
 928
 929                 if (container->v2)
 930                         ret = tce_iommu_build_v2(container, tbl,
 931                                         param.iova >> tbl->it_page_shift,
 932                                         param.vaddr,
 933                                         param.size >> tbl->it_page_shift,
 934                                         direction);
 935                 else
 936                         ret = tce_iommu_build(container, tbl,
 937                                         param.iova >> tbl->it_page_shift,
 938                                         param.vaddr,
 939                                         param.size >> tbl->it_page_shift,
 940                                         direction);
 941
 942                 iommu_flush_tce(tbl);
 943
 944                 return ret;
 945         }
 946         case VFIO_IOMMU_UNMAP_DMA: {
 947                 struct vfio_iommu_type1_dma_unmap param;
 948                 struct iommu_table *tbl = NULL;
 949                 long num;
 950
 951                 if (!container->enabled)
 952                         return -EPERM;
 953
 954                 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
 955                                 size);
 956
 957                 if (copy_from_user(&param, (void __user *)arg, minsz))
 958                         return -EFAULT;
 959
 960                 if (param.argsz < minsz)
 961                         return -EINVAL;
 962
 963                 /* No flag is supported now */
 964                 if (param.flags)
 965                         return -EINVAL;
 966
 967                 ret = tce_iommu_create_default_window(container);
 968                 if (ret)
 969                         return ret;
 970
 971                 num = tce_iommu_find_table(container, param.iova, &tbl);
 972                 if (num < 0)
 973                         return -ENXIO;
 974
 975                 if (param.size & ~IOMMU_PAGE_MASK(tbl))
 976                         return -EINVAL;
 977
 978                 ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
 979                                 param.size >> tbl->it_page_shift);
 980                 if (ret)
 981                         return ret;
 982
 983                 ret = tce_iommu_clear(container, tbl,
 984                                 param.iova >> tbl->it_page_shift,
 985                                 param.size >> tbl->it_page_shift);
 986                 iommu_flush_tce(tbl);
 987
 988                 return ret;
 989         }
 990         case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
 991                 struct vfio_iommu_spapr_register_memory param;
 992
 993                 if (!container->v2)
 994                         break;
 995
 996                 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
 997                                 size);
 998
 999                 ret = tce_iommu_mm_set(container);
1000                 if (ret)
1001                         return ret;
1002
1003                 if (copy_from_user(&param, (void __user *)arg, minsz))
1004                         return -EFAULT;
1005
1006                 if (param.argsz < minsz)
1007                         return -EINVAL;
1008
1009                 /* No flag is supported now */
1010                 if (param.flags)
1011                         return -EINVAL;
1012
1013                 mutex_lock(&container->lock);
1014                 ret = tce_iommu_register_pages(container, param.vaddr,
1015                                 param.size);
1016                 mutex_unlock(&container->lock);
1017
1018                 return ret;
1019         }
1020         case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
1021                 struct vfio_iommu_spapr_register_memory param;
1022
1023                 if (!container->v2)
1024                         break;
1025
1026                 if (!container->mm)
1027                         return -EPERM;
1028
1029                 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1030                                 size);
1031
1032                 if (copy_from_user(&param, (void __user *)arg, minsz))
1033                         return -EFAULT;
1034
1035                 if (param.argsz < minsz)
1036                         return -EINVAL;
1037
1038                 /* No flag is supported now */
1039                 if (param.flags)
1040                         return -EINVAL;
1041
1042                 mutex_lock(&container->lock);
1043                 ret = tce_iommu_unregister_pages(container, param.vaddr,
1044                                 param.size);
1045                 mutex_unlock(&container->lock);
1046
1047                 return ret;
1048         }
1049         case VFIO_IOMMU_ENABLE:
1050                 if (container->v2)
1051                         break;
1052
1053                 mutex_lock(&container->lock);
1054                 ret = tce_iommu_enable(container);
1055                 mutex_unlock(&container->lock);
1056                 return ret;
1057
1058
1059         case VFIO_IOMMU_DISABLE:
1060                 if (container->v2)
1061                         break;
1062
1063                 mutex_lock(&container->lock);
1064                 tce_iommu_disable(container);
1065                 mutex_unlock(&container->lock);
1066                 return 0;
1067
1068         case VFIO_EEH_PE_OP: {
1069                 struct tce_iommu_group *tcegrp;
1070
1071                 ret = 0;
1072                 list_for_each_entry(tcegrp, &container->group_list, next) {
1073                         ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
1074                                         cmd, arg);
1075                         if (ret)
1076                                 return ret;
1077                 }
1078                 return ret;
1079         }
1080
1081         case VFIO_IOMMU_SPAPR_TCE_CREATE: {
1082                 struct vfio_iommu_spapr_tce_create create;
1083
1084                 if (!container->v2)
1085                         break;
1086
1087                 ret = tce_iommu_mm_set(container);
1088                 if (ret)
1089                         return ret;
1090
1091                 if (!tce_groups_attached(container))
1092                         return -ENXIO;
1093
1094                 minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
1095                                 start_addr);
1096
1097                 if (copy_from_user(&create, (void __user *)arg, minsz))
1098                         return -EFAULT;
1099
1100                 if (create.argsz < minsz)
1101                         return -EINVAL;
1102
1103                 if (create.flags)
1104                         return -EINVAL;
1105
1106                 mutex_lock(&container->lock);
1107
1108                 ret = tce_iommu_create_default_window(container);
1109                 if (!ret)
1110                         ret = tce_iommu_create_window(container,
1111                                         create.page_shift,
1112                                         create.window_size, create.levels,
1113                                         &create.start_addr);
1114
1115                 mutex_unlock(&container->lock);
1116
1117                 if (!ret && copy_to_user((void __user *)arg, &create, minsz))
1118                         ret = -EFAULT;
1119
1120                 return ret;
1121         }
1122         case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
1123                 struct vfio_iommu_spapr_tce_remove remove;
1124
1125                 if (!container->v2)
1126                         break;
1127
1128                 ret = tce_iommu_mm_set(container);
1129                 if (ret)
1130                         return ret;
1131
1132                 if (!tce_groups_attached(container))
1133                         return -ENXIO;
1134
1135                 minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
1136                                 start_addr);
1137
1138                 if (copy_from_user(&remove, (void __user *)arg, minsz))
1139                         return -EFAULT;
1140
1141                 if (remove.argsz < minsz)
1142                         return -EINVAL;
1143
1144                 if (remove.flags)
1145                         return -EINVAL;
1146
1147                 if (container->def_window_pending && !remove.start_addr) {
1148                         container->def_window_pending = false;
1149                         return 0;
1150                 }
1151
1152                 mutex_lock(&container->lock);
1153
1154                 ret = tce_iommu_remove_window(container, remove.start_addr);
1155
1156                 mutex_unlock(&container->lock);
1157
1158                 return ret;
1159         }
1160         }
1161
1162         return -ENOTTY;
1163 }
1164
1165 static void tce_iommu_release_ownership(struct tce_container *container,
1166                 struct iommu_table_group *table_group)
1167 {
1168         int i;
1169
1170         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1171                 struct iommu_table *tbl = container->tables[i];
1172
1173                 if (!tbl)
1174                         continue;
1175
1176                 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
1177                 if (tbl->it_map)
1178                         iommu_release_ownership(tbl);
1179
1180                 container->tables[i] = NULL;
1181         }
1182 }
1183
1184 static int tce_iommu_take_ownership(struct tce_container *container,
1185                 struct iommu_table_group *table_group)
1186 {
1187         int i, j, rc = 0;
1188
1189         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1190                 struct iommu_table *tbl = table_group->tables[i];
1191
1192                 if (!tbl || !tbl->it_map)
1193                         continue;
1194
1195                 rc = iommu_take_ownership(tbl);
1196                 if (rc) {
1197                         for (j = 0; j < i; ++j)
1198                                 iommu_release_ownership(
1199                                                 table_group->tables[j]);
1200
1201                         return rc;
1202                 }
1203         }
1204
1205         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1206                 container->tables[i] = table_group->tables[i];
1207
1208         return 0;
1209 }
1210
1211 static void tce_iommu_release_ownership_ddw(struct tce_container *container,
1212                 struct iommu_table_group *table_group)
1213 {
1214         long i;
1215
1216         if (!table_group->ops->unset_window) {
1217                 WARN_ON_ONCE(1);
1218                 return;
1219         }
1220
1221         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1222                 table_group->ops->unset_window(table_group, i);
1223
1224         table_group->ops->release_ownership(table_group);
1225 }
1226
1227 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
1228                 struct iommu_table_group *table_group)
1229 {
1230         long i, ret = 0;
1231
1232         if (!table_group->ops->create_table || !table_group->ops->set_window ||
1233                         !table_group->ops->release_ownership) {
1234                 WARN_ON_ONCE(1);
1235                 return -EFAULT;
1236         }
1237
1238         table_group->ops->take_ownership(table_group);
1239
1240         /* Set all windows to the new group */
1241         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1242                 struct iommu_table *tbl = container->tables[i];
1243
1244                 if (!tbl)
1245                         continue;
1246
1247                 ret = table_group->ops->set_window(table_group, i, tbl);
1248                 if (ret)
1249                         goto release_exit;
1250         }
1251
1252         return 0;
1253
1254 release_exit:
1255         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1256                 table_group->ops->unset_window(table_group, i);
1257
1258         table_group->ops->release_ownership(table_group);
1259
1260         return ret;
1261 }
1262
1263 static int tce_iommu_attach_group(void *iommu_data,
1264                 struct iommu_group *iommu_group)
1265 {
1266         int ret;
1267         struct tce_container *container = iommu_data;
1268         struct iommu_table_group *table_group;
1269         struct tce_iommu_group *tcegrp = NULL;
1270
1271         mutex_lock(&container->lock);
1272
1273         /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
1274                         iommu_group_id(iommu_group), iommu_group); */
1275         table_group = iommu_group_get_iommudata(iommu_group);
1276         if (!table_group) {
1277                 ret = -ENODEV;
1278                 goto unlock_exit;
1279         }
1280
1281         if (tce_groups_attached(container) && (!table_group->ops ||
1282                         !table_group->ops->take_ownership ||
1283                         !table_group->ops->release_ownership)) {
1284                 ret = -EBUSY;
1285                 goto unlock_exit;
1286         }
1287
1288         /* Check if new group has the same iommu_ops (i.e. compatible) */
1289         list_for_each_entry(tcegrp, &container->group_list, next) {
1290                 struct iommu_table_group *table_group_tmp;
1291
1292                 if (tcegrp->grp == iommu_group) {
1293                         pr_warn("tce_vfio: Group %d is already attached\n",
1294                                         iommu_group_id(iommu_group));
1295                         ret = -EBUSY;
1296                         goto unlock_exit;
1297                 }
1298                 table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
1299                 if (table_group_tmp->ops->create_table !=
1300                                 table_group->ops->create_table) {
1301                         pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
1302                                         iommu_group_id(iommu_group),
1303                                         iommu_group_id(tcegrp->grp));
1304                         ret = -EPERM;
1305                         goto unlock_exit;
1306                 }
1307         }
1308
1309         tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
1310         if (!tcegrp) {
1311                 ret = -ENOMEM;
1312                 goto unlock_exit;
1313         }
1314
1315         if (!table_group->ops || !table_group->ops->take_ownership ||
1316                         !table_group->ops->release_ownership) {
1317                 if (container->v2) {
1318                         ret = -EPERM;
1319                         goto unlock_exit;
1320                 }
1321                 ret = tce_iommu_take_ownership(container, table_group);
1322         } else {
1323                 if (!container->v2) {
1324                         ret = -EPERM;
1325                         goto unlock_exit;
1326                 }
1327                 ret = tce_iommu_take_ownership_ddw(container, table_group);
1328                 if (!tce_groups_attached(container) && !container->tables[0])
1329                         container->def_window_pending = true;
1330         }
1331
1332         if (!ret) {
1333                 tcegrp->grp = iommu_group;
1334                 list_add(&tcegrp->next, &container->group_list);
1335         }
1336
1337 unlock_exit:
1338         if (ret && tcegrp)
1339                 kfree(tcegrp);
1340
1341         mutex_unlock(&container->lock);
1342
1343         return ret;
1344 }
1345
1346 static void tce_iommu_detach_group(void *iommu_data,
1347                 struct iommu_group *iommu_group)
1348 {
1349         struct tce_container *container = iommu_data;
1350         struct iommu_table_group *table_group;
1351         bool found = false;
1352         struct tce_iommu_group *tcegrp;
1353
1354         mutex_lock(&container->lock);
1355
1356         list_for_each_entry(tcegrp, &container->group_list, next) {
1357                 if (tcegrp->grp == iommu_group) {
1358                         found = true;
1359                         break;
1360                 }
1361         }
1362
1363         if (!found) {
1364                 pr_warn("tce_vfio: detaching unattached group #%u\n",
1365                                 iommu_group_id(iommu_group));
1366                 goto unlock_exit;
1367         }
1368
1369         list_del(&tcegrp->next);
1370         kfree(tcegrp);
1371
1372         table_group = iommu_group_get_iommudata(iommu_group);
1373         BUG_ON(!table_group);
1374
1375         if (!table_group->ops || !table_group->ops->release_ownership)
1376                 tce_iommu_release_ownership(container, table_group);
1377         else
1378                 tce_iommu_release_ownership_ddw(container, table_group);
1379
1380 unlock_exit:
1381         mutex_unlock(&container->lock);
1382 }
1383
1384 const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
1385         .name           = "iommu-vfio-powerpc",
1386         .owner          = THIS_MODULE,
1387         .open           = tce_iommu_open,
1388         .release        = tce_iommu_release,
1389         .ioctl          = tce_iommu_ioctl,
1390         .attach_group   = tce_iommu_attach_group,
1391         .detach_group   = tce_iommu_detach_group,
1392 };
1393
1394 static int __init tce_iommu_init(void)
1395 {
1396         return vfio_register_iommu_driver(&tce_iommu_driver_ops);
1397 }
1398
1399 static void __exit tce_iommu_cleanup(void)
1400 {
1401         vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
1402 }
1403
1404 module_init(tce_iommu_init);
1405 module_exit(tce_iommu_cleanup);
1406
1407 MODULE_VERSION(DRIVER_VERSION);
1408 MODULE_LICENSE("GPL v2");
1409 MODULE_AUTHOR(DRIVER_AUTHOR);
1410 MODULE_DESCRIPTION(DRIVER_DESC);
1411