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