drivers/vfio/vfio_iommu_spapr_tce.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VFIO: IOMMU DMA mapping support for TCE on POWER
   4  *
   5  * Copyright (C) 2013 IBM Corp.  All rights reserved.
   6  *     Author: Alexey Kardashevskiy <[email protected]>
   7  *
   8  * Derived from original vfio_iommu_type1.c:
   9  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
  10  *     Author: Alex Williamson <[email protected]>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/pci.h>
  15 #include <linux/slab.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/err.h>
  18 #include <linux/vfio.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/sched/mm.h>
  21 #include <linux/sched/signal.h>
  22 #include <linux/mm.h>
  23 #include "vfio.h"
  24
  25 #include <asm/iommu.h>
  26 #include <asm/tce.h>
  27 #include <asm/mmu_context.h>
  28
  29 #define DRIVER_VERSION  "0.1"
  30 #define DRIVER_AUTHOR   "[email protected]"
  31 #define DRIVER_DESC     "VFIO IOMMU SPAPR TCE"
  32
  33 static void tce_iommu_detach_group(void *iommu_data,
  34                 struct iommu_group *iommu_group);
  35
  36 /*
  37  * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
  38  *
  39  * This code handles mapping and unmapping of user data buffers
  40  * into DMA'ble space using the IOMMU
  41  */
  42
  43 struct tce_iommu_group {
  44         struct list_head next;
  45         struct iommu_group *grp;
  46 };
  47
  48 /*
  49  * A container needs to remember which preregistered region  it has
  50  * referenced to do proper cleanup at the userspace process exit.
  51  */
  52 struct tce_iommu_prereg {
  53         struct list_head next;
  54         struct mm_iommu_table_group_mem_t *mem;
  55 };
  56
  57 /*
  58  * The container descriptor supports only a single group per container.
  59  * Required by the API as the container is not supplied with the IOMMU group
  60  * at the moment of initialization.
  61  */
  62 struct tce_container {
  63         struct mutex lock;
  64         bool enabled;
  65         bool v2;
  66         bool def_window_pending;
  67         unsigned long locked_pages;
  68         struct mm_struct *mm;
  69         struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
  70         struct list_head group_list;
  71         struct list_head prereg_list;
  72 };
  73
  74 static long tce_iommu_mm_set(struct tce_container *container)
  75 {
  76         if (container->mm) {
  77                 if (container->mm == current->mm)
  78                         return 0;
  79                 return -EPERM;
  80         }
  81         BUG_ON(!current->mm);
  82         container->mm = current->mm;
  83         mmgrab(container->mm);
  84
  85         return 0;
  86 }
  87
  88 static long tce_iommu_prereg_free(struct tce_container *container,
  89                 struct tce_iommu_prereg *tcemem)
  90 {
  91         long ret;
  92
  93         ret = mm_iommu_put(container->mm, tcemem->mem);
  94         if (ret)
  95                 return ret;
  96
  97         list_del(&tcemem->next);
  98         kfree(tcemem);
  99
 100         return 0;
 101 }
 102
 103 static long tce_iommu_unregister_pages(struct tce_container *container,
 104                 __u64 vaddr, __u64 size)
 105 {
 106         struct mm_iommu_table_group_mem_t *mem;
 107         struct tce_iommu_prereg *tcemem;
 108         bool found = false;
 109         long ret;
 110
 111         if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
 112                 return -EINVAL;
 113
 114         mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT);
 115         if (!mem)
 116                 return -ENOENT;
 117
 118         list_for_each_entry(tcemem, &container->prereg_list, next) {
 119                 if (tcemem->mem == mem) {
 120                         found = true;
 121                         break;
 122                 }
 123         }
 124
 125         if (!found)
 126                 ret = -ENOENT;
 127         else
 128                 ret = tce_iommu_prereg_free(container, tcemem);
 129
 130         mm_iommu_put(container->mm, mem);
 131
 132         return ret;
 133 }
 134
 135 static long tce_iommu_register_pages(struct tce_container *container,
 136                 __u64 vaddr, __u64 size)
 137 {
 138         long ret = 0;
 139         struct mm_iommu_table_group_mem_t *mem = NULL;
 140         struct tce_iommu_prereg *tcemem;
 141         unsigned long entries = size >> PAGE_SHIFT;
 142
 143         if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
 144                         ((vaddr + size) < vaddr))
 145                 return -EINVAL;
 146
 147         mem = mm_iommu_get(container->mm, vaddr, entries);
 148         if (mem) {
 149                 list_for_each_entry(tcemem, &container->prereg_list, next) {
 150                         if (tcemem->mem == mem) {
 151                                 ret = -EBUSY;
 152                                 goto put_exit;
 153                         }
 154                 }
 155         } else {
 156                 ret = mm_iommu_new(container->mm, vaddr, entries, &mem);
 157                 if (ret)
 158                         return ret;
 159         }
 160
 161         tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
 162         if (!tcemem) {
 163                 ret = -ENOMEM;
 164                 goto put_exit;
 165         }
 166
 167         tcemem->mem = mem;
 168         list_add(&tcemem->next, &container->prereg_list);
 169
 170         container->enabled = true;
 171
 172         return 0;
 173
 174 put_exit:
 175         mm_iommu_put(container->mm, mem);
 176         return ret;
 177 }
 178
 179 static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
 180                 unsigned int it_page_shift)
 181 {
 182         struct page *page;
 183         unsigned long size = 0;
 184
 185         if (mm_iommu_is_devmem(mm, hpa, it_page_shift, &size))
 186                 return size == (1UL << it_page_shift);
 187
 188         page = pfn_to_page(hpa >> PAGE_SHIFT);
 189         /*
 190          * Check that the TCE table granularity is not bigger than the size of
 191          * a page we just found. Otherwise the hardware can get access to
 192          * a bigger memory chunk that it should.
 193          */
 194         return page_shift(compound_head(page)) >= it_page_shift;
 195 }
 196
 197 static inline bool tce_groups_attached(struct tce_container *container)
 198 {
 199         return !list_empty(&container->group_list);
 200 }
 201
 202 static long tce_iommu_find_table(struct tce_container *container,
 203                 phys_addr_t ioba, struct iommu_table **ptbl)
 204 {
 205         long i;
 206
 207         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 208                 struct iommu_table *tbl = container->tables[i];
 209
 210                 if (tbl) {
 211                         unsigned long entry = ioba >> tbl->it_page_shift;
 212                         unsigned long start = tbl->it_offset;
 213                         unsigned long end = start + tbl->it_size;
 214
 215                         if ((start <= entry) && (entry < end)) {
 216                                 *ptbl = tbl;
 217                                 return i;
 218                         }
 219                 }
 220         }
 221
 222         return -1;
 223 }
 224
 225 static int tce_iommu_find_free_table(struct tce_container *container)
 226 {
 227         int i;
 228
 229         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 230                 if (!container->tables[i])
 231                         return i;
 232         }
 233
 234         return -ENOSPC;
 235 }
 236
 237 static int tce_iommu_enable(struct tce_container *container)
 238 {
 239         int ret = 0;
 240         unsigned long locked;
 241         struct iommu_table_group *table_group;
 242         struct tce_iommu_group *tcegrp;
 243
 244         if (container->enabled)
 245                 return -EBUSY;
 246
 247         /*
 248          * When userspace pages are mapped into the IOMMU, they are effectively
 249          * locked memory, so, theoretically, we need to update the accounting
 250          * of locked pages on each map and unmap.  For powerpc, the map unmap
 251          * paths can be very hot, though, and the accounting would kill
 252          * performance, especially since it would be difficult to impossible
 253          * to handle the accounting in real mode only.
 254          *
 255          * To address that, rather than precisely accounting every page, we
 256          * instead account for a worst case on locked memory when the iommu is
 257          * enabled and disabled.  The worst case upper bound on locked memory
 258          * is the size of the whole iommu window, which is usually relatively
 259          * small (compared to total memory sizes) on POWER hardware.
 260          *
 261          * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
 262          * that would effectively kill the guest at random points, much better
 263          * enforcing the limit based on the max that the guest can map.
 264          *
 265          * Unfortunately at the moment it counts whole tables, no matter how
 266          * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
 267          * each with 2GB DMA window, 8GB will be counted here. The reason for
 268          * this is that we cannot tell here the amount of RAM used by the guest
 269          * as this information is only available from KVM and VFIO is
 270          * KVM agnostic.
 271          *
 272          * So we do not allow enabling a container without a group attached
 273          * as there is no way to know how much we should increment
 274          * the locked_vm counter.
 275          */
 276         if (!tce_groups_attached(container))
 277                 return -ENODEV;
 278
 279         tcegrp = list_first_entry(&container->group_list,
 280                         struct tce_iommu_group, next);
 281         table_group = iommu_group_get_iommudata(tcegrp->grp);
 282         if (!table_group)
 283                 return -ENODEV;
 284
 285         if (!table_group->tce32_size)
 286                 return -EPERM;
 287
 288         ret = tce_iommu_mm_set(container);
 289         if (ret)
 290                 return ret;
 291
 292         locked = table_group->tce32_size >> PAGE_SHIFT;
 293         ret = account_locked_vm(container->mm, locked, true);
 294         if (ret)
 295                 return ret;
 296
 297         container->locked_pages = locked;
 298
 299         container->enabled = true;
 300
 301         return ret;
 302 }
 303
 304 static void tce_iommu_disable(struct tce_container *container)
 305 {
 306         if (!container->enabled)
 307                 return;
 308
 309         container->enabled = false;
 310
 311         BUG_ON(!container->mm);
 312         account_locked_vm(container->mm, container->locked_pages, false);
 313 }
 314
 315 static void *tce_iommu_open(unsigned long arg)
 316 {
 317         struct tce_container *container;
 318
 319         if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
 320                 pr_err("tce_vfio: Wrong IOMMU type\n");
 321                 return ERR_PTR(-EINVAL);
 322         }
 323
 324         container = kzalloc(sizeof(*container), GFP_KERNEL);
 325         if (!container)
 326                 return ERR_PTR(-ENOMEM);
 327
 328         mutex_init(&container->lock);
 329         INIT_LIST_HEAD_RCU(&container->group_list);
 330         INIT_LIST_HEAD_RCU(&container->prereg_list);
 331
 332         container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
 333
 334         return container;
 335 }
 336
 337 static int tce_iommu_clear(struct tce_container *container,
 338                 struct iommu_table *tbl,
 339                 unsigned long entry, unsigned long pages);
 340 static void tce_iommu_free_table(struct tce_container *container,
 341                 struct iommu_table *tbl);
 342
 343 static void tce_iommu_release(void *iommu_data)
 344 {
 345         struct tce_container *container = iommu_data;
 346         struct tce_iommu_group *tcegrp;
 347         struct tce_iommu_prereg *tcemem, *tmtmp;
 348         long i;
 349
 350         while (tce_groups_attached(container)) {
 351                 tcegrp = list_first_entry(&container->group_list,
 352                                 struct tce_iommu_group, next);
 353                 tce_iommu_detach_group(iommu_data, tcegrp->grp);
 354         }
 355
 356         /*
 357          * If VFIO created a table, it was not disposed
 358          * by tce_iommu_detach_group() so do it now.
 359          */
 360         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 361                 struct iommu_table *tbl = container->tables[i];
 362
 363                 if (!tbl)
 364                         continue;
 365
 366                 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
 367                 tce_iommu_free_table(container, tbl);
 368         }
 369
 370         list_for_each_entry_safe(tcemem, tmtmp, &container->prereg_list, next)
 371                 WARN_ON(tce_iommu_prereg_free(container, tcemem));
 372
 373         tce_iommu_disable(container);
 374         if (container->mm)
 375                 mmdrop(container->mm);
 376         mutex_destroy(&container->lock);
 377
 378         kfree(container);
 379 }
 380
 381 static void tce_iommu_unuse_page(struct tce_container *container,
 382                 unsigned long hpa)
 383 {
 384         struct page *page;
 385
 386         page = pfn_to_page(hpa >> PAGE_SHIFT);
 387         unpin_user_page(page);
 388 }
 389
 390 static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
 391                 unsigned long tce, unsigned long shift,
 392                 unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
 393 {
 394         long ret = 0;
 395         struct mm_iommu_table_group_mem_t *mem;
 396
 397         mem = mm_iommu_lookup(container->mm, tce, 1ULL << shift);
 398         if (!mem)
 399                 return -EINVAL;
 400
 401         ret = mm_iommu_ua_to_hpa(mem, tce, shift, phpa);
 402         if (ret)
 403                 return -EINVAL;
 404
 405         *pmem = mem;
 406
 407         return 0;
 408 }
 409
 410 static void tce_iommu_unuse_page_v2(struct tce_container *container,
 411                 struct iommu_table *tbl, unsigned long entry)
 412 {
 413         struct mm_iommu_table_group_mem_t *mem = NULL;
 414         int ret;
 415         unsigned long hpa = 0;
 416         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
 417
 418         if (!pua)
 419                 return;
 420
 421         ret = tce_iommu_prereg_ua_to_hpa(container, be64_to_cpu(*pua),
 422                         tbl->it_page_shift, &hpa, &mem);
 423         if (ret)
 424                 pr_debug("%s: tce %llx at #%lx was not cached, ret=%d\n",
 425                                 __func__, be64_to_cpu(*pua), entry, ret);
 426         if (mem)
 427                 mm_iommu_mapped_dec(mem);
 428
 429         *pua = cpu_to_be64(0);
 430 }
 431
 432 static int tce_iommu_clear(struct tce_container *container,
 433                 struct iommu_table *tbl,
 434                 unsigned long entry, unsigned long pages)
 435 {
 436         unsigned long oldhpa;
 437         long ret;
 438         enum dma_data_direction direction;
 439         unsigned long lastentry = entry + pages, firstentry = entry;
 440
 441         for ( ; entry < lastentry; ++entry) {
 442                 if (tbl->it_indirect_levels && tbl->it_userspace) {
 443                         /*
 444                          * For multilevel tables, we can take a shortcut here
 445                          * and skip some TCEs as we know that the userspace
 446                          * addresses cache is a mirror of the real TCE table
 447                          * and if it is missing some indirect levels, then
 448                          * the hardware table does not have them allocated
 449                          * either and therefore does not require updating.
 450                          */
 451                         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl,
 452                                         entry);
 453                         if (!pua) {
 454                                 /* align to level_size which is power of two */
 455                                 entry |= tbl->it_level_size - 1;
 456                                 continue;
 457                         }
 458                 }
 459
 460                 cond_resched();
 461
 462                 direction = DMA_NONE;
 463                 oldhpa = 0;
 464                 ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry, &oldhpa,
 465                                 &direction);
 466                 if (ret)
 467                         continue;
 468
 469                 if (direction == DMA_NONE)
 470                         continue;
 471
 472                 if (container->v2) {
 473                         tce_iommu_unuse_page_v2(container, tbl, entry);
 474                         continue;
 475                 }
 476
 477                 tce_iommu_unuse_page(container, oldhpa);
 478         }
 479
 480         iommu_tce_kill(tbl, firstentry, pages);
 481
 482         return 0;
 483 }
 484
 485 static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
 486 {
 487         struct page *page = NULL;
 488         enum dma_data_direction direction = iommu_tce_direction(tce);
 489
 490         if (pin_user_pages_fast(tce & PAGE_MASK, 1,
 491                         direction != DMA_TO_DEVICE ? FOLL_WRITE : 0,
 492                         &page) != 1)
 493                 return -EFAULT;
 494
 495         *hpa = __pa((unsigned long) page_address(page));
 496
 497         return 0;
 498 }
 499
 500 static long tce_iommu_build(struct tce_container *container,
 501                 struct iommu_table *tbl,
 502                 unsigned long entry, unsigned long tce, unsigned long pages,
 503                 enum dma_data_direction direction)
 504 {
 505         long i, ret = 0;
 506         unsigned long hpa;
 507         enum dma_data_direction dirtmp;
 508
 509         for (i = 0; i < pages; ++i) {
 510                 unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
 511
 512                 ret = tce_iommu_use_page(tce, &hpa);
 513                 if (ret)
 514                         break;
 515
 516                 if (!tce_page_is_contained(container->mm, hpa,
 517                                 tbl->it_page_shift)) {
 518                         ret = -EPERM;
 519                         break;
 520                 }
 521
 522                 hpa |= offset;
 523                 dirtmp = direction;
 524                 ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
 525                                 &hpa, &dirtmp);
 526                 if (ret) {
 527                         tce_iommu_unuse_page(container, hpa);
 528                         pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
 529                                         __func__, entry << tbl->it_page_shift,
 530                                         tce, ret);
 531                         break;
 532                 }
 533
 534                 if (dirtmp != DMA_NONE)
 535                         tce_iommu_unuse_page(container, hpa);
 536
 537                 tce += IOMMU_PAGE_SIZE(tbl);
 538         }
 539
 540         if (ret)
 541                 tce_iommu_clear(container, tbl, entry, i);
 542         else
 543                 iommu_tce_kill(tbl, entry, pages);
 544
 545         return ret;
 546 }
 547
 548 static long tce_iommu_build_v2(struct tce_container *container,
 549                 struct iommu_table *tbl,
 550                 unsigned long entry, unsigned long tce, unsigned long pages,
 551                 enum dma_data_direction direction)
 552 {
 553         long i, ret = 0;
 554         unsigned long hpa;
 555         enum dma_data_direction dirtmp;
 556
 557         for (i = 0; i < pages; ++i) {
 558                 struct mm_iommu_table_group_mem_t *mem = NULL;
 559                 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i);
 560
 561                 ret = tce_iommu_prereg_ua_to_hpa(container,
 562                                 tce, tbl->it_page_shift, &hpa, &mem);
 563                 if (ret)
 564                         break;
 565
 566                 if (!tce_page_is_contained(container->mm, hpa,
 567                                 tbl->it_page_shift)) {
 568                         ret = -EPERM;
 569                         break;
 570                 }
 571
 572                 /* Preserve offset within IOMMU page */
 573                 hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
 574                 dirtmp = direction;
 575
 576                 /* The registered region is being unregistered */
 577                 if (mm_iommu_mapped_inc(mem))
 578                         break;
 579
 580                 ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
 581                                 &hpa, &dirtmp);
 582                 if (ret) {
 583                         /* dirtmp cannot be DMA_NONE here */
 584                         tce_iommu_unuse_page_v2(container, tbl, entry + i);
 585                         pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
 586                                         __func__, entry << tbl->it_page_shift,
 587                                         tce, ret);
 588                         break;
 589                 }
 590
 591                 if (dirtmp != DMA_NONE)
 592                         tce_iommu_unuse_page_v2(container, tbl, entry + i);
 593
 594                 *pua = cpu_to_be64(tce);
 595
 596                 tce += IOMMU_PAGE_SIZE(tbl);
 597         }
 598
 599         if (ret)
 600                 tce_iommu_clear(container, tbl, entry, i);
 601         else
 602                 iommu_tce_kill(tbl, entry, pages);
 603
 604         return ret;
 605 }
 606
 607 static long tce_iommu_create_table(struct tce_container *container,
 608                         struct iommu_table_group *table_group,
 609                         int num,
 610                         __u32 page_shift,
 611                         __u64 window_size,
 612                         __u32 levels,
 613                         struct iommu_table **ptbl)
 614 {
 615         long ret, table_size;
 616
 617         table_size = table_group->ops->get_table_size(page_shift, window_size,
 618                         levels);
 619         if (!table_size)
 620                 return -EINVAL;
 621
 622         ret = account_locked_vm(container->mm, table_size >> PAGE_SHIFT, true);
 623         if (ret)
 624                 return ret;
 625
 626         ret = table_group->ops->create_table(table_group, num,
 627                         page_shift, window_size, levels, ptbl);
 628
 629         WARN_ON(!ret && !(*ptbl)->it_ops->free);
 630         WARN_ON(!ret && ((*ptbl)->it_allocated_size > table_size));
 631
 632         return ret;
 633 }
 634
 635 static void tce_iommu_free_table(struct tce_container *container,
 636                 struct iommu_table *tbl)
 637 {
 638         unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
 639
 640         iommu_tce_table_put(tbl);
 641         account_locked_vm(container->mm, pages, false);
 642 }
 643
 644 static long tce_iommu_create_window(struct tce_container *container,
 645                 __u32 page_shift, __u64 window_size, __u32 levels,
 646                 __u64 *start_addr)
 647 {
 648         struct tce_iommu_group *tcegrp;
 649         struct iommu_table_group *table_group;
 650         struct iommu_table *tbl = NULL;
 651         long ret, num;
 652
 653         num = tce_iommu_find_free_table(container);
 654         if (num < 0)
 655                 return num;
 656
 657         /* Get the first group for ops::create_table */
 658         tcegrp = list_first_entry(&container->group_list,
 659                         struct tce_iommu_group, next);
 660         table_group = iommu_group_get_iommudata(tcegrp->grp);
 661         if (!table_group)
 662                 return -EFAULT;
 663
 664         if (!(table_group->pgsizes & (1ULL << page_shift)))
 665                 return -EINVAL;
 666
 667         if (!table_group->ops->set_window || !table_group->ops->unset_window ||
 668                         !table_group->ops->get_table_size ||
 669                         !table_group->ops->create_table)
 670                 return -EPERM;
 671
 672         /* Create TCE table */
 673         ret = tce_iommu_create_table(container, table_group, num,
 674                         page_shift, window_size, levels, &tbl);
 675         if (ret)
 676                 return ret;
 677
 678         BUG_ON(!tbl->it_ops->free);
 679
 680         /*
 681          * Program the table to every group.
 682          * Groups have been tested for compatibility at the attach time.
 683          */
 684         list_for_each_entry(tcegrp, &container->group_list, next) {
 685                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 686
 687                 ret = table_group->ops->set_window(table_group, num, tbl);
 688                 if (ret)
 689                         goto unset_exit;
 690         }
 691
 692         container->tables[num] = tbl;
 693
 694         /* Return start address assigned by platform in create_table() */
 695         *start_addr = tbl->it_offset << tbl->it_page_shift;
 696
 697         return 0;
 698
 699 unset_exit:
 700         list_for_each_entry(tcegrp, &container->group_list, next) {
 701                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 702                 table_group->ops->unset_window(table_group, num);
 703         }
 704         tce_iommu_free_table(container, tbl);
 705
 706         return ret;
 707 }
 708
 709 static long tce_iommu_remove_window(struct tce_container *container,
 710                 __u64 start_addr)
 711 {
 712         struct iommu_table_group *table_group = NULL;
 713         struct iommu_table *tbl;
 714         struct tce_iommu_group *tcegrp;
 715         int num;
 716
 717         num = tce_iommu_find_table(container, start_addr, &tbl);
 718         if (num < 0)
 719                 return -EINVAL;
 720
 721         BUG_ON(!tbl->it_size);
 722
 723         /* Detach groups from IOMMUs */
 724         list_for_each_entry(tcegrp, &container->group_list, next) {
 725                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 726
 727                 /*
 728                  * SPAPR TCE IOMMU exposes the default DMA window to
 729                  * the guest via dma32_window_start/size of
 730                  * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
 731                  * the userspace to remove this window, some do not so
 732                  * here we check for the platform capability.
 733                  */
 734                 if (!table_group->ops || !table_group->ops->unset_window)
 735                         return -EPERM;
 736
 737                 table_group->ops->unset_window(table_group, num);
 738         }
 739
 740         /* Free table */
 741         tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
 742         tce_iommu_free_table(container, tbl);
 743         container->tables[num] = NULL;
 744
 745         return 0;
 746 }
 747
 748 static long tce_iommu_create_default_window(struct tce_container *container)
 749 {
 750         long ret;
 751         __u64 start_addr = 0;
 752         struct tce_iommu_group *tcegrp;
 753         struct iommu_table_group *table_group;
 754
 755         if (!container->def_window_pending)
 756                 return 0;
 757
 758         if (!tce_groups_attached(container))
 759                 return -ENODEV;
 760
 761         tcegrp = list_first_entry(&container->group_list,
 762                         struct tce_iommu_group, next);
 763         table_group = iommu_group_get_iommudata(tcegrp->grp);
 764         if (!table_group)
 765                 return -ENODEV;
 766
 767         ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
 768                         table_group->tce32_size, 1, &start_addr);
 769         WARN_ON_ONCE(!ret && start_addr);
 770
 771         if (!ret)
 772                 container->def_window_pending = false;
 773
 774         return ret;
 775 }
 776
 777 static long tce_iommu_ioctl(void *iommu_data,
 778                                  unsigned int cmd, unsigned long arg)
 779 {
 780         struct tce_container *container = iommu_data;
 781         unsigned long minsz, ddwsz;
 782         long ret;
 783
 784         switch (cmd) {
 785         case VFIO_CHECK_EXTENSION:
 786                 switch (arg) {
 787                 case VFIO_SPAPR_TCE_IOMMU:
 788                 case VFIO_SPAPR_TCE_v2_IOMMU:
 789                         ret = 1;
 790                         break;
 791                 default:
 792                         ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
 793                         break;
 794                 }
 795
 796                 return (ret < 0) ? 0 : ret;
 797         }
 798
 799         /*
 800          * Sanity check to prevent one userspace from manipulating
 801          * another userspace mm.
 802          */
 803         BUG_ON(!container);
 804         if (container->mm && container->mm != current->mm)
 805                 return -EPERM;
 806
 807         switch (cmd) {
 808         case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
 809                 struct vfio_iommu_spapr_tce_info info;
 810                 struct tce_iommu_group *tcegrp;
 811                 struct iommu_table_group *table_group;
 812
 813                 if (!tce_groups_attached(container))
 814                         return -ENXIO;
 815
 816                 tcegrp = list_first_entry(&container->group_list,
 817                                 struct tce_iommu_group, next);
 818                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 819
 820                 if (!table_group)
 821                         return -ENXIO;
 822
 823                 minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
 824                                 dma32_window_size);
 825
 826                 if (copy_from_user(&info, (void __user *)arg, minsz))
 827                         return -EFAULT;
 828
 829                 if (info.argsz < minsz)
 830                         return -EINVAL;
 831
 832                 info.dma32_window_start = table_group->tce32_start;
 833                 info.dma32_window_size = table_group->tce32_size;
 834                 info.flags = 0;
 835                 memset(&info.ddw, 0, sizeof(info.ddw));
 836
 837                 if (table_group->max_dynamic_windows_supported &&
 838                                 container->v2) {
 839                         info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
 840                         info.ddw.pgsizes = table_group->pgsizes;
 841                         info.ddw.max_dynamic_windows_supported =
 842                                 table_group->max_dynamic_windows_supported;
 843                         info.ddw.levels = table_group->max_levels;
 844                 }
 845
 846                 ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
 847
 848                 if (info.argsz >= ddwsz)
 849                         minsz = ddwsz;
 850
 851                 if (copy_to_user((void __user *)arg, &info, minsz))
 852                         return -EFAULT;
 853
 854                 return 0;
 855         }
 856         case VFIO_IOMMU_MAP_DMA: {
 857                 struct vfio_iommu_type1_dma_map param;
 858                 struct iommu_table *tbl = NULL;
 859                 long num;
 860                 enum dma_data_direction direction;
 861
 862                 if (!container->enabled)
 863                         return -EPERM;
 864
 865                 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
 866
 867                 if (copy_from_user(&param, (void __user *)arg, minsz))
 868                         return -EFAULT;
 869
 870                 if (param.argsz < minsz)
 871                         return -EINVAL;
 872
 873                 if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
 874                                 VFIO_DMA_MAP_FLAG_WRITE))
 875                         return -EINVAL;
 876
 877                 ret = tce_iommu_create_default_window(container);
 878                 if (ret)
 879                         return ret;
 880
 881                 num = tce_iommu_find_table(container, param.iova, &tbl);
 882                 if (num < 0)
 883                         return -ENXIO;
 884
 885                 if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
 886                                 (param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
 887                         return -EINVAL;
 888
 889                 /* iova is checked by the IOMMU API */
 890                 if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
 891                         if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
 892                                 direction = DMA_BIDIRECTIONAL;
 893                         else
 894                                 direction = DMA_TO_DEVICE;
 895                 } else {
 896                         if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
 897                                 direction = DMA_FROM_DEVICE;
 898                         else
 899                                 return -EINVAL;
 900                 }
 901
 902                 ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
 903                 if (ret)
 904                         return ret;
 905
 906                 if (container->v2)
 907                         ret = tce_iommu_build_v2(container, tbl,
 908                                         param.iova >> tbl->it_page_shift,
 909                                         param.vaddr,
 910                                         param.size >> tbl->it_page_shift,
 911                                         direction);
 912                 else
 913                         ret = tce_iommu_build(container, tbl,
 914                                         param.iova >> tbl->it_page_shift,
 915                                         param.vaddr,
 916                                         param.size >> tbl->it_page_shift,
 917                                         direction);
 918
 919                 iommu_flush_tce(tbl);
 920
 921                 return ret;
 922         }
 923         case VFIO_IOMMU_UNMAP_DMA: {
 924                 struct vfio_iommu_type1_dma_unmap param;
 925                 struct iommu_table *tbl = NULL;
 926                 long num;
 927
 928                 if (!container->enabled)
 929                         return -EPERM;
 930
 931                 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
 932                                 size);
 933
 934                 if (copy_from_user(&param, (void __user *)arg, minsz))
 935                         return -EFAULT;
 936
 937                 if (param.argsz < minsz)
 938                         return -EINVAL;
 939
 940                 /* No flag is supported now */
 941                 if (param.flags)
 942                         return -EINVAL;
 943
 944                 ret = tce_iommu_create_default_window(container);
 945                 if (ret)
 946                         return ret;
 947
 948                 num = tce_iommu_find_table(container, param.iova, &tbl);
 949                 if (num < 0)
 950                         return -ENXIO;
 951
 952                 if (param.size & ~IOMMU_PAGE_MASK(tbl))
 953                         return -EINVAL;
 954
 955                 ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
 956                                 param.size >> tbl->it_page_shift);
 957                 if (ret)
 958                         return ret;
 959
 960                 ret = tce_iommu_clear(container, tbl,
 961                                 param.iova >> tbl->it_page_shift,
 962                                 param.size >> tbl->it_page_shift);
 963                 iommu_flush_tce(tbl);
 964
 965                 return ret;
 966         }
 967         case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
 968                 struct vfio_iommu_spapr_register_memory param;
 969
 970                 if (!container->v2)
 971                         break;
 972
 973                 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
 974                                 size);
 975
 976                 ret = tce_iommu_mm_set(container);
 977                 if (ret)
 978                         return ret;
 979
 980                 if (copy_from_user(&param, (void __user *)arg, minsz))
 981                         return -EFAULT;
 982
 983                 if (param.argsz < minsz)
 984                         return -EINVAL;
 985
 986                 /* No flag is supported now */
 987                 if (param.flags)
 988                         return -EINVAL;
 989
 990                 mutex_lock(&container->lock);
 991                 ret = tce_iommu_register_pages(container, param.vaddr,
 992                                 param.size);
 993                 mutex_unlock(&container->lock);
 994
 995                 return ret;
 996         }
 997         case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
 998                 struct vfio_iommu_spapr_register_memory param;
 999
1000                 if (!container->v2)
1001                         break;
1002
1003                 if (!container->mm)
1004                         return -EPERM;
1005
1006                 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1007                                 size);
1008
1009                 if (copy_from_user(&param, (void __user *)arg, minsz))
1010                         return -EFAULT;
1011
1012                 if (param.argsz < minsz)
1013                         return -EINVAL;
1014
1015                 /* No flag is supported now */
1016                 if (param.flags)
1017                         return -EINVAL;
1018
1019                 mutex_lock(&container->lock);
1020                 ret = tce_iommu_unregister_pages(container, param.vaddr,
1021                                 param.size);
1022                 mutex_unlock(&container->lock);
1023
1024                 return ret;
1025         }
1026         case VFIO_IOMMU_ENABLE:
1027                 if (container->v2)
1028                         break;
1029
1030                 mutex_lock(&container->lock);
1031                 ret = tce_iommu_enable(container);
1032                 mutex_unlock(&container->lock);
1033                 return ret;
1034
1035
1036         case VFIO_IOMMU_DISABLE:
1037                 if (container->v2)
1038                         break;
1039
1040                 mutex_lock(&container->lock);
1041                 tce_iommu_disable(container);
1042                 mutex_unlock(&container->lock);
1043                 return 0;
1044
1045         case VFIO_EEH_PE_OP: {
1046                 struct tce_iommu_group *tcegrp;
1047
1048                 ret = 0;
1049                 list_for_each_entry(tcegrp, &container->group_list, next) {
1050                         ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
1051                                         cmd, arg);
1052                         if (ret)
1053                                 return ret;
1054                 }
1055                 return ret;
1056         }
1057
1058         case VFIO_IOMMU_SPAPR_TCE_CREATE: {
1059                 struct vfio_iommu_spapr_tce_create create;
1060
1061                 if (!container->v2)
1062                         break;
1063
1064                 ret = tce_iommu_mm_set(container);
1065                 if (ret)
1066                         return ret;
1067
1068                 if (!tce_groups_attached(container))
1069                         return -ENXIO;
1070
1071                 minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
1072                                 start_addr);
1073
1074                 if (copy_from_user(&create, (void __user *)arg, minsz))
1075                         return -EFAULT;
1076
1077                 if (create.argsz < minsz)
1078                         return -EINVAL;
1079
1080                 if (create.flags)
1081                         return -EINVAL;
1082
1083                 mutex_lock(&container->lock);
1084
1085                 ret = tce_iommu_create_default_window(container);
1086                 if (!ret)
1087                         ret = tce_iommu_create_window(container,
1088                                         create.page_shift,
1089                                         create.window_size, create.levels,
1090                                         &create.start_addr);
1091
1092                 mutex_unlock(&container->lock);
1093
1094                 if (!ret && copy_to_user((void __user *)arg, &create, minsz))
1095                         ret = -EFAULT;
1096
1097                 return ret;
1098         }
1099         case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
1100                 struct vfio_iommu_spapr_tce_remove remove;
1101
1102                 if (!container->v2)
1103                         break;
1104
1105                 ret = tce_iommu_mm_set(container);
1106                 if (ret)
1107                         return ret;
1108
1109                 if (!tce_groups_attached(container))
1110                         return -ENXIO;
1111
1112                 minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
1113                                 start_addr);
1114
1115                 if (copy_from_user(&remove, (void __user *)arg, minsz))
1116                         return -EFAULT;
1117
1118                 if (remove.argsz < minsz)
1119                         return -EINVAL;
1120
1121                 if (remove.flags)
1122                         return -EINVAL;
1123
1124                 if (container->def_window_pending && !remove.start_addr) {
1125                         container->def_window_pending = false;
1126                         return 0;
1127                 }
1128
1129                 mutex_lock(&container->lock);
1130
1131                 ret = tce_iommu_remove_window(container, remove.start_addr);
1132
1133                 mutex_unlock(&container->lock);
1134
1135                 return ret;
1136         }
1137         }
1138
1139         return -ENOTTY;
1140 }
1141
1142 static void tce_iommu_release_ownership(struct tce_container *container,
1143                 struct iommu_table_group *table_group)
1144 {
1145         int i;
1146
1147         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1148                 struct iommu_table *tbl = container->tables[i];
1149
1150                 if (!tbl)
1151                         continue;
1152
1153                 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
1154                 if (tbl->it_map)
1155                         iommu_release_ownership(tbl);
1156
1157                 container->tables[i] = NULL;
1158         }
1159 }
1160
1161 static int tce_iommu_take_ownership(struct tce_container *container,
1162                 struct iommu_table_group *table_group)
1163 {
1164         int i, j, rc = 0;
1165
1166         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1167                 struct iommu_table *tbl = table_group->tables[i];
1168
1169                 if (!tbl || !tbl->it_map)
1170                         continue;
1171
1172                 rc = iommu_take_ownership(tbl);
1173                 if (rc) {
1174                         for (j = 0; j < i; ++j)
1175                                 iommu_release_ownership(
1176                                                 table_group->tables[j]);
1177
1178                         return rc;
1179                 }
1180         }
1181
1182         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1183                 container->tables[i] = table_group->tables[i];
1184
1185         return 0;
1186 }
1187
1188 static void tce_iommu_release_ownership_ddw(struct tce_container *container,
1189                 struct iommu_table_group *table_group)
1190 {
1191         long i;
1192
1193         if (!table_group->ops->unset_window) {
1194                 WARN_ON_ONCE(1);
1195                 return;
1196         }
1197
1198         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1199                 if (container->tables[i])
1200                         table_group->ops->unset_window(table_group, i);
1201
1202         table_group->ops->release_ownership(table_group);
1203 }
1204
1205 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
1206                 struct iommu_table_group *table_group)
1207 {
1208         long i, ret = 0;
1209
1210         if (!table_group->ops->create_table || !table_group->ops->set_window ||
1211                         !table_group->ops->release_ownership) {
1212                 WARN_ON_ONCE(1);
1213                 return -EFAULT;
1214         }
1215
1216         table_group->ops->take_ownership(table_group);
1217
1218         /* Set all windows to the new group */
1219         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1220                 struct iommu_table *tbl = container->tables[i];
1221
1222                 if (!tbl)
1223                         continue;
1224
1225                 ret = table_group->ops->set_window(table_group, i, tbl);
1226                 if (ret)
1227                         goto release_exit;
1228         }
1229
1230         return 0;
1231
1232 release_exit:
1233         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1234                 table_group->ops->unset_window(table_group, i);
1235
1236         table_group->ops->release_ownership(table_group);
1237
1238         return ret;
1239 }
1240
1241 static int tce_iommu_attach_group(void *iommu_data,
1242                 struct iommu_group *iommu_group, enum vfio_group_type type)
1243 {
1244         int ret = 0;
1245         struct tce_container *container = iommu_data;
1246         struct iommu_table_group *table_group;
1247         struct tce_iommu_group *tcegrp = NULL;
1248
1249         if (type == VFIO_EMULATED_IOMMU)
1250                 return -EINVAL;
1251
1252         mutex_lock(&container->lock);
1253
1254         /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
1255                         iommu_group_id(iommu_group), iommu_group); */
1256         table_group = iommu_group_get_iommudata(iommu_group);
1257         if (!table_group) {
1258                 ret = -ENODEV;
1259                 goto unlock_exit;
1260         }
1261
1262         if (tce_groups_attached(container) && (!table_group->ops ||
1263                         !table_group->ops->take_ownership ||
1264                         !table_group->ops->release_ownership)) {
1265                 ret = -EBUSY;
1266                 goto unlock_exit;
1267         }
1268
1269         /* Check if new group has the same iommu_ops (i.e. compatible) */
1270         list_for_each_entry(tcegrp, &container->group_list, next) {
1271                 struct iommu_table_group *table_group_tmp;
1272
1273                 if (tcegrp->grp == iommu_group) {
1274                         pr_warn("tce_vfio: Group %d is already attached\n",
1275                                         iommu_group_id(iommu_group));
1276                         ret = -EBUSY;
1277                         goto unlock_exit;
1278                 }
1279                 table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
1280                 if (table_group_tmp->ops->create_table !=
1281                                 table_group->ops->create_table) {
1282                         pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
1283                                         iommu_group_id(iommu_group),
1284                                         iommu_group_id(tcegrp->grp));
1285                         ret = -EPERM;
1286                         goto unlock_exit;
1287                 }
1288         }
1289
1290         tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
1291         if (!tcegrp) {
1292                 ret = -ENOMEM;
1293                 goto unlock_exit;
1294         }
1295
1296         if (!table_group->ops || !table_group->ops->take_ownership ||
1297                         !table_group->ops->release_ownership) {
1298                 if (container->v2) {
1299                         ret = -EPERM;
1300                         goto free_exit;
1301                 }
1302                 ret = tce_iommu_take_ownership(container, table_group);
1303         } else {
1304                 if (!container->v2) {
1305                         ret = -EPERM;
1306                         goto free_exit;
1307                 }
1308                 ret = tce_iommu_take_ownership_ddw(container, table_group);
1309                 if (!tce_groups_attached(container) && !container->tables[0])
1310                         container->def_window_pending = true;
1311         }
1312
1313         if (!ret) {
1314                 tcegrp->grp = iommu_group;
1315                 list_add(&tcegrp->next, &container->group_list);
1316         }
1317
1318 free_exit:
1319         if (ret && tcegrp)
1320                 kfree(tcegrp);
1321
1322 unlock_exit:
1323         mutex_unlock(&container->lock);
1324
1325         return ret;
1326 }
1327
1328 static void tce_iommu_detach_group(void *iommu_data,
1329                 struct iommu_group *iommu_group)
1330 {
1331         struct tce_container *container = iommu_data;
1332         struct iommu_table_group *table_group;
1333         bool found = false;
1334         struct tce_iommu_group *tcegrp;
1335
1336         mutex_lock(&container->lock);
1337
1338         list_for_each_entry(tcegrp, &container->group_list, next) {
1339                 if (tcegrp->grp == iommu_group) {
1340                         found = true;
1341                         break;
1342                 }
1343         }
1344
1345         if (!found) {
1346                 pr_warn("tce_vfio: detaching unattached group #%u\n",
1347                                 iommu_group_id(iommu_group));
1348                 goto unlock_exit;
1349         }
1350
1351         list_del(&tcegrp->next);
1352         kfree(tcegrp);
1353
1354         table_group = iommu_group_get_iommudata(iommu_group);
1355         BUG_ON(!table_group);
1356
1357         if (!table_group->ops || !table_group->ops->release_ownership)
1358                 tce_iommu_release_ownership(container, table_group);
1359         else
1360                 tce_iommu_release_ownership_ddw(container, table_group);
1361
1362 unlock_exit:
1363         mutex_unlock(&container->lock);
1364 }
1365
1366 static const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
1367         .name           = "iommu-vfio-powerpc",
1368         .owner          = THIS_MODULE,
1369         .open           = tce_iommu_open,
1370         .release        = tce_iommu_release,
1371         .ioctl          = tce_iommu_ioctl,
1372         .attach_group   = tce_iommu_attach_group,
1373         .detach_group   = tce_iommu_detach_group,
1374 };
1375
1376 static int __init tce_iommu_init(void)
1377 {
1378         return vfio_register_iommu_driver(&tce_iommu_driver_ops);
1379 }
1380
1381 static void __exit tce_iommu_cleanup(void)
1382 {
1383         vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
1384 }
1385
1386 module_init(tce_iommu_init);
1387 module_exit(tce_iommu_cleanup);
1388
1389 MODULE_VERSION(DRIVER_VERSION);
1390 MODULE_LICENSE("GPL v2");
1391 MODULE_AUTHOR(DRIVER_AUTHOR);
1392 MODULE_DESCRIPTION(DRIVER_DESC);
1393