drivers/iommu/apple-dart.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Apple DART (Device Address Resolution Table) IOMMU driver
   4  *
   5  * Copyright (C) 2021 The Asahi Linux Contributors
   6  *
   7  * Based on arm/arm-smmu/arm-ssmu.c and arm/arm-smmu-v3/arm-smmu-v3.c
   8  *  Copyright (C) 2013 ARM Limited
   9  *  Copyright (C) 2015 ARM Limited
  10  * and on exynos-iommu.c
  11  *  Copyright (c) 2011,2016 Samsung Electronics Co., Ltd.
  12  */
  13
  14 #include <linux/atomic.h>
  15 #include <linux/bitfield.h>
  16 #include <linux/clk.h>
  17 #include <linux/dev_printk.h>
  18 #include <linux/dma-iommu.h>
  19 #include <linux/dma-mapping.h>
  20 #include <linux/err.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/io-pgtable.h>
  23 #include <linux/iommu.h>
  24 #include <linux/iopoll.h>
  25 #include <linux/module.h>
  26 #include <linux/of.h>
  27 #include <linux/of_address.h>
  28 #include <linux/of_iommu.h>
  29 #include <linux/of_platform.h>
  30 #include <linux/pci.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/slab.h>
  33 #include <linux/swab.h>
  34 #include <linux/types.h>
  35
  36 #define DART_MAX_STREAMS 16
  37 #define DART_MAX_TTBR 4
  38 #define MAX_DARTS_PER_DEVICE 2
  39
  40 #define DART_STREAM_ALL 0xffff
  41
  42 #define DART_PARAMS1 0x00
  43 #define DART_PARAMS_PAGE_SHIFT GENMASK(27, 24)
  44
  45 #define DART_PARAMS2 0x04
  46 #define DART_PARAMS_BYPASS_SUPPORT BIT(0)
  47
  48 #define DART_STREAM_COMMAND 0x20
  49 #define DART_STREAM_COMMAND_BUSY BIT(2)
  50 #define DART_STREAM_COMMAND_INVALIDATE BIT(20)
  51
  52 #define DART_STREAM_SELECT 0x34
  53
  54 #define DART_ERROR 0x40
  55 #define DART_ERROR_STREAM GENMASK(27, 24)
  56 #define DART_ERROR_CODE GENMASK(11, 0)
  57 #define DART_ERROR_FLAG BIT(31)
  58
  59 #define DART_ERROR_READ_FAULT BIT(4)
  60 #define DART_ERROR_WRITE_FAULT BIT(3)
  61 #define DART_ERROR_NO_PTE BIT(2)
  62 #define DART_ERROR_NO_PMD BIT(1)
  63 #define DART_ERROR_NO_TTBR BIT(0)
  64
  65 #define DART_CONFIG 0x60
  66 #define DART_CONFIG_LOCK BIT(15)
  67
  68 #define DART_STREAM_COMMAND_BUSY_TIMEOUT 100
  69
  70 #define DART_ERROR_ADDR_HI 0x54
  71 #define DART_ERROR_ADDR_LO 0x50
  72
  73 #define DART_STREAMS_ENABLE 0xfc
  74
  75 #define DART_TCR(sid) (0x100 + 4 * (sid))
  76 #define DART_TCR_TRANSLATE_ENABLE BIT(7)
  77 #define DART_TCR_BYPASS0_ENABLE BIT(8)
  78 #define DART_TCR_BYPASS1_ENABLE BIT(12)
  79
  80 #define DART_TTBR(sid, idx) (0x200 + 16 * (sid) + 4 * (idx))
  81 #define DART_TTBR_VALID BIT(31)
  82 #define DART_TTBR_SHIFT 12
  83
  84 /*
  85  * Private structure associated with each DART device.
  86  *
  87  * @dev: device struct
  88  * @regs: mapped MMIO region
  89  * @irq: interrupt number, can be shared with other DARTs
  90  * @clks: clocks associated with this DART
  91  * @num_clks: number of @clks
  92  * @lock: lock for hardware operations involving this dart
  93  * @pgsize: pagesize supported by this DART
  94  * @supports_bypass: indicates if this DART supports bypass mode
  95  * @force_bypass: force bypass mode due to pagesize mismatch?
  96  * @sid2group: maps stream ids to iommu_groups
  97  * @iommu: iommu core device
  98  */
  99 struct apple_dart {
 100         struct device *dev;
 101
 102         void __iomem *regs;
 103
 104         int irq;
 105         struct clk_bulk_data *clks;
 106         int num_clks;
 107
 108         spinlock_t lock;
 109
 110         u32 pgsize;
 111         u32 supports_bypass : 1;
 112         u32 force_bypass : 1;
 113
 114         struct iommu_group *sid2group[DART_MAX_STREAMS];
 115         struct iommu_device iommu;
 116 };
 117
 118 /*
 119  * Convenience struct to identify streams.
 120  *
 121  * The normal variant is used inside apple_dart_master_cfg which isn't written
 122  * to concurrently.
 123  * The atomic variant is used inside apple_dart_domain where we have to guard
 124  * against races from potential parallel calls to attach/detach_device.
 125  * Note that even inside the atomic variant the apple_dart pointer is not
 126  * protected: This pointer is initialized once under the domain init mutex
 127  * and never changed again afterwards. Devices with different dart pointers
 128  * cannot be attached to the same domain.
 129  *
 130  * @dart dart pointer
 131  * @sid stream id bitmap
 132  */
 133 struct apple_dart_stream_map {
 134         struct apple_dart *dart;
 135         unsigned long sidmap;
 136 };
 137 struct apple_dart_atomic_stream_map {
 138         struct apple_dart *dart;
 139         atomic64_t sidmap;
 140 };
 141
 142 /*
 143  * This structure is attached to each iommu domain handled by a DART.
 144  *
 145  * @pgtbl_ops: pagetable ops allocated by io-pgtable
 146  * @finalized: true if the domain has been completely initialized
 147  * @init_lock: protects domain initialization
 148  * @stream_maps: streams attached to this domain (valid for DMA/UNMANAGED only)
 149  * @domain: core iommu domain pointer
 150  */
 151 struct apple_dart_domain {
 152         struct io_pgtable_ops *pgtbl_ops;
 153
 154         bool finalized;
 155         struct mutex init_lock;
 156         struct apple_dart_atomic_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
 157
 158         struct iommu_domain domain;
 159 };
 160
 161 /*
 162  * This structure is attached to devices with dev_iommu_priv_set() on of_xlate
 163  * and contains a list of streams bound to this device.
 164  * So far the worst case seen is a single device with two streams
 165  * from different darts, such that this simple static array is enough.
 166  *
 167  * @streams: streams for this device
 168  */
 169 struct apple_dart_master_cfg {
 170         struct apple_dart_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
 171 };
 172
 173 /*
 174  * Helper macro to iterate over apple_dart_master_cfg.stream_maps and
 175  * apple_dart_domain.stream_maps
 176  *
 177  * @i int used as loop variable
 178  * @base pointer to base struct (apple_dart_master_cfg or apple_dart_domain)
 179  * @stream pointer to the apple_dart_streams struct for each loop iteration
 180  */
 181 #define for_each_stream_map(i, base, stream_map)                               \
 182         for (i = 0, stream_map = &(base)->stream_maps[0];                      \
 183              i < MAX_DARTS_PER_DEVICE && stream_map->dart;                     \
 184              stream_map = &(base)->stream_maps[++i])
 185
 186 static struct platform_driver apple_dart_driver;
 187 static const struct iommu_ops apple_dart_iommu_ops;
 188
 189 static struct apple_dart_domain *to_dart_domain(struct iommu_domain *dom)
 190 {
 191         return container_of(dom, struct apple_dart_domain, domain);
 192 }
 193
 194 static void
 195 apple_dart_hw_enable_translation(struct apple_dart_stream_map *stream_map)
 196 {
 197         int sid;
 198
 199         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 200                 writel(DART_TCR_TRANSLATE_ENABLE,
 201                        stream_map->dart->regs + DART_TCR(sid));
 202 }
 203
 204 static void apple_dart_hw_disable_dma(struct apple_dart_stream_map *stream_map)
 205 {
 206         int sid;
 207
 208         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 209                 writel(0, stream_map->dart->regs + DART_TCR(sid));
 210 }
 211
 212 static void
 213 apple_dart_hw_enable_bypass(struct apple_dart_stream_map *stream_map)
 214 {
 215         int sid;
 216
 217         WARN_ON(!stream_map->dart->supports_bypass);
 218         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 219                 writel(DART_TCR_BYPASS0_ENABLE | DART_TCR_BYPASS1_ENABLE,
 220                        stream_map->dart->regs + DART_TCR(sid));
 221 }
 222
 223 static void apple_dart_hw_set_ttbr(struct apple_dart_stream_map *stream_map,
 224                                    u8 idx, phys_addr_t paddr)
 225 {
 226         int sid;
 227
 228         WARN_ON(paddr & ((1 << DART_TTBR_SHIFT) - 1));
 229         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 230                 writel(DART_TTBR_VALID | (paddr >> DART_TTBR_SHIFT),
 231                        stream_map->dart->regs + DART_TTBR(sid, idx));
 232 }
 233
 234 static void apple_dart_hw_clear_ttbr(struct apple_dart_stream_map *stream_map,
 235                                      u8 idx)
 236 {
 237         int sid;
 238
 239         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 240                 writel(0, stream_map->dart->regs + DART_TTBR(sid, idx));
 241 }
 242
 243 static void
 244 apple_dart_hw_clear_all_ttbrs(struct apple_dart_stream_map *stream_map)
 245 {
 246         int i;
 247
 248         for (i = 0; i < DART_MAX_TTBR; ++i)
 249                 apple_dart_hw_clear_ttbr(stream_map, i);
 250 }
 251
 252 static int
 253 apple_dart_hw_stream_command(struct apple_dart_stream_map *stream_map,
 254                              u32 command)
 255 {
 256         unsigned long flags;
 257         int ret;
 258         u32 command_reg;
 259
 260         spin_lock_irqsave(&stream_map->dart->lock, flags);
 261
 262         writel(stream_map->sidmap, stream_map->dart->regs + DART_STREAM_SELECT);
 263         writel(command, stream_map->dart->regs + DART_STREAM_COMMAND);
 264
 265         ret = readl_poll_timeout_atomic(
 266                 stream_map->dart->regs + DART_STREAM_COMMAND, command_reg,
 267                 !(command_reg & DART_STREAM_COMMAND_BUSY), 1,
 268                 DART_STREAM_COMMAND_BUSY_TIMEOUT);
 269
 270         spin_unlock_irqrestore(&stream_map->dart->lock, flags);
 271
 272         if (ret) {
 273                 dev_err(stream_map->dart->dev,
 274                         "busy bit did not clear after command %x for streams %lx\n",
 275                         command, stream_map->sidmap);
 276                 return ret;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int
 283 apple_dart_hw_invalidate_tlb(struct apple_dart_stream_map *stream_map)
 284 {
 285         return apple_dart_hw_stream_command(stream_map,
 286                                             DART_STREAM_COMMAND_INVALIDATE);
 287 }
 288
 289 static int apple_dart_hw_reset(struct apple_dart *dart)
 290 {
 291         u32 config;
 292         struct apple_dart_stream_map stream_map;
 293
 294         config = readl(dart->regs + DART_CONFIG);
 295         if (config & DART_CONFIG_LOCK) {
 296                 dev_err(dart->dev, "DART is locked down until reboot: %08x\n",
 297                         config);
 298                 return -EINVAL;
 299         }
 300
 301         stream_map.dart = dart;
 302         stream_map.sidmap = DART_STREAM_ALL;
 303         apple_dart_hw_disable_dma(&stream_map);
 304         apple_dart_hw_clear_all_ttbrs(&stream_map);
 305
 306         /* enable all streams globally since TCR is used to control isolation */
 307         writel(DART_STREAM_ALL, dart->regs + DART_STREAMS_ENABLE);
 308
 309         /* clear any pending errors before the interrupt is unmasked */
 310         writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR);
 311
 312         return apple_dart_hw_invalidate_tlb(&stream_map);
 313 }
 314
 315 static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain)
 316 {
 317         int i;
 318         struct apple_dart_atomic_stream_map *domain_stream_map;
 319         struct apple_dart_stream_map stream_map;
 320
 321         for_each_stream_map(i, domain, domain_stream_map) {
 322                 stream_map.dart = domain_stream_map->dart;
 323                 stream_map.sidmap = atomic64_read(&domain_stream_map->sidmap);
 324                 apple_dart_hw_invalidate_tlb(&stream_map);
 325         }
 326 }
 327
 328 static void apple_dart_flush_iotlb_all(struct iommu_domain *domain)
 329 {
 330         apple_dart_domain_flush_tlb(to_dart_domain(domain));
 331 }
 332
 333 static void apple_dart_iotlb_sync(struct iommu_domain *domain,
 334                                   struct iommu_iotlb_gather *gather)
 335 {
 336         apple_dart_domain_flush_tlb(to_dart_domain(domain));
 337 }
 338
 339 static void apple_dart_iotlb_sync_map(struct iommu_domain *domain,
 340                                       unsigned long iova, size_t size)
 341 {
 342         apple_dart_domain_flush_tlb(to_dart_domain(domain));
 343 }
 344
 345 static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain,
 346                                            dma_addr_t iova)
 347 {
 348         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 349         struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
 350
 351         if (!ops)
 352                 return 0;
 353
 354         return ops->iova_to_phys(ops, iova);
 355 }
 356
 357 static int apple_dart_map_pages(struct iommu_domain *domain, unsigned long iova,
 358                                 phys_addr_t paddr, size_t pgsize,
 359                                 size_t pgcount, int prot, gfp_t gfp,
 360                                 size_t *mapped)
 361 {
 362         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 363         struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
 364
 365         if (!ops)
 366                 return -ENODEV;
 367
 368         return ops->map_pages(ops, iova, paddr, pgsize, pgcount, prot, gfp,
 369                               mapped);
 370 }
 371
 372 static size_t apple_dart_unmap_pages(struct iommu_domain *domain,
 373                                      unsigned long iova, size_t pgsize,
 374                                      size_t pgcount,
 375                                      struct iommu_iotlb_gather *gather)
 376 {
 377         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 378         struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
 379
 380         return ops->unmap_pages(ops, iova, pgsize, pgcount, gather);
 381 }
 382
 383 static void
 384 apple_dart_setup_translation(struct apple_dart_domain *domain,
 385                              struct apple_dart_stream_map *stream_map)
 386 {
 387         int i;
 388         struct io_pgtable_cfg *pgtbl_cfg =
 389                 &io_pgtable_ops_to_pgtable(domain->pgtbl_ops)->cfg;
 390
 391         for (i = 0; i < pgtbl_cfg->apple_dart_cfg.n_ttbrs; ++i)
 392                 apple_dart_hw_set_ttbr(stream_map, i,
 393                                        pgtbl_cfg->apple_dart_cfg.ttbr[i]);
 394         for (; i < DART_MAX_TTBR; ++i)
 395                 apple_dart_hw_clear_ttbr(stream_map, i);
 396
 397         apple_dart_hw_enable_translation(stream_map);
 398         apple_dart_hw_invalidate_tlb(stream_map);
 399 }
 400
 401 static int apple_dart_finalize_domain(struct iommu_domain *domain,
 402                                       struct apple_dart_master_cfg *cfg)
 403 {
 404         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 405         struct apple_dart *dart = cfg->stream_maps[0].dart;
 406         struct io_pgtable_cfg pgtbl_cfg;
 407         int ret = 0;
 408         int i;
 409
 410         mutex_lock(&dart_domain->init_lock);
 411
 412         if (dart_domain->finalized)
 413                 goto done;
 414
 415         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 416                 dart_domain->stream_maps[i].dart = cfg->stream_maps[i].dart;
 417                 atomic64_set(&dart_domain->stream_maps[i].sidmap,
 418                              cfg->stream_maps[i].sidmap);
 419         }
 420
 421         pgtbl_cfg = (struct io_pgtable_cfg){
 422                 .pgsize_bitmap = dart->pgsize,
 423                 .ias = 32,
 424                 .oas = 36,
 425                 .coherent_walk = 1,
 426                 .iommu_dev = dart->dev,
 427         };
 428
 429         dart_domain->pgtbl_ops =
 430                 alloc_io_pgtable_ops(APPLE_DART, &pgtbl_cfg, domain);
 431         if (!dart_domain->pgtbl_ops) {
 432                 ret = -ENOMEM;
 433                 goto done;
 434         }
 435
 436         domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap;
 437         domain->geometry.aperture_start = 0;
 438         domain->geometry.aperture_end = DMA_BIT_MASK(32);
 439         domain->geometry.force_aperture = true;
 440
 441         dart_domain->finalized = true;
 442
 443 done:
 444         mutex_unlock(&dart_domain->init_lock);
 445         return ret;
 446 }
 447
 448 static int
 449 apple_dart_mod_streams(struct apple_dart_atomic_stream_map *domain_maps,
 450                        struct apple_dart_stream_map *master_maps,
 451                        bool add_streams)
 452 {
 453         int i;
 454
 455         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 456                 if (domain_maps[i].dart != master_maps[i].dart)
 457                         return -EINVAL;
 458         }
 459
 460         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 461                 if (!domain_maps[i].dart)
 462                         break;
 463                 if (add_streams)
 464                         atomic64_or(master_maps[i].sidmap,
 465                                     &domain_maps[i].sidmap);
 466                 else
 467                         atomic64_and(~master_maps[i].sidmap,
 468                                      &domain_maps[i].sidmap);
 469         }
 470
 471         return 0;
 472 }
 473
 474 static int apple_dart_domain_add_streams(struct apple_dart_domain *domain,
 475                                          struct apple_dart_master_cfg *cfg)
 476 {
 477         return apple_dart_mod_streams(domain->stream_maps, cfg->stream_maps,
 478                                       true);
 479 }
 480
 481 static int apple_dart_domain_remove_streams(struct apple_dart_domain *domain,
 482                                             struct apple_dart_master_cfg *cfg)
 483 {
 484         return apple_dart_mod_streams(domain->stream_maps, cfg->stream_maps,
 485                                       false);
 486 }
 487
 488 static int apple_dart_attach_dev(struct iommu_domain *domain,
 489                                  struct device *dev)
 490 {
 491         int ret, i;
 492         struct apple_dart_stream_map *stream_map;
 493         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 494         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 495
 496         if (cfg->stream_maps[0].dart->force_bypass &&
 497             domain->type != IOMMU_DOMAIN_IDENTITY)
 498                 return -EINVAL;
 499         if (!cfg->stream_maps[0].dart->supports_bypass &&
 500             domain->type == IOMMU_DOMAIN_IDENTITY)
 501                 return -EINVAL;
 502
 503         ret = apple_dart_finalize_domain(domain, cfg);
 504         if (ret)
 505                 return ret;
 506
 507         switch (domain->type) {
 508         case IOMMU_DOMAIN_DMA:
 509         case IOMMU_DOMAIN_UNMANAGED:
 510                 ret = apple_dart_domain_add_streams(dart_domain, cfg);
 511                 if (ret)
 512                         return ret;
 513
 514                 for_each_stream_map(i, cfg, stream_map)
 515                         apple_dart_setup_translation(dart_domain, stream_map);
 516                 break;
 517         case IOMMU_DOMAIN_BLOCKED:
 518                 for_each_stream_map(i, cfg, stream_map)
 519                         apple_dart_hw_disable_dma(stream_map);
 520                 break;
 521         case IOMMU_DOMAIN_IDENTITY:
 522                 for_each_stream_map(i, cfg, stream_map)
 523                         apple_dart_hw_enable_bypass(stream_map);
 524                 break;
 525         }
 526
 527         return ret;
 528 }
 529
 530 static void apple_dart_detach_dev(struct iommu_domain *domain,
 531                                   struct device *dev)
 532 {
 533         int i;
 534         struct apple_dart_stream_map *stream_map;
 535         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 536         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 537
 538         for_each_stream_map(i, cfg, stream_map)
 539                 apple_dart_hw_disable_dma(stream_map);
 540
 541         if (domain->type == IOMMU_DOMAIN_DMA ||
 542             domain->type == IOMMU_DOMAIN_UNMANAGED)
 543                 apple_dart_domain_remove_streams(dart_domain, cfg);
 544 }
 545
 546 static struct iommu_device *apple_dart_probe_device(struct device *dev)
 547 {
 548         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 549         struct apple_dart_stream_map *stream_map;
 550         int i;
 551
 552         if (!cfg)
 553                 return ERR_PTR(-ENODEV);
 554
 555         for_each_stream_map(i, cfg, stream_map)
 556                 device_link_add(
 557                         dev, stream_map->dart->dev,
 558                         DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER);
 559
 560         return &cfg->stream_maps[0].dart->iommu;
 561 }
 562
 563 static void apple_dart_release_device(struct device *dev)
 564 {
 565         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 566
 567         if (!cfg)
 568                 return;
 569
 570         dev_iommu_priv_set(dev, NULL);
 571         kfree(cfg);
 572 }
 573
 574 static struct iommu_domain *apple_dart_domain_alloc(unsigned int type)
 575 {
 576         struct apple_dart_domain *dart_domain;
 577
 578         if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED &&
 579             type != IOMMU_DOMAIN_IDENTITY && type != IOMMU_DOMAIN_BLOCKED)
 580                 return NULL;
 581
 582         dart_domain = kzalloc(sizeof(*dart_domain), GFP_KERNEL);
 583         if (!dart_domain)
 584                 return NULL;
 585
 586         mutex_init(&dart_domain->init_lock);
 587
 588         /* no need to allocate pgtbl_ops or do any other finalization steps */
 589         if (type == IOMMU_DOMAIN_IDENTITY || type == IOMMU_DOMAIN_BLOCKED)
 590                 dart_domain->finalized = true;
 591
 592         return &dart_domain->domain;
 593 }
 594
 595 static void apple_dart_domain_free(struct iommu_domain *domain)
 596 {
 597         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 598
 599         if (dart_domain->pgtbl_ops)
 600                 free_io_pgtable_ops(dart_domain->pgtbl_ops);
 601
 602         kfree(dart_domain);
 603 }
 604
 605 static int apple_dart_of_xlate(struct device *dev, struct of_phandle_args *args)
 606 {
 607         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 608         struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
 609         struct apple_dart *dart = platform_get_drvdata(iommu_pdev);
 610         struct apple_dart *cfg_dart;
 611         int i, sid;
 612
 613         if (args->args_count != 1)
 614                 return -EINVAL;
 615         sid = args->args[0];
 616
 617         if (!cfg)
 618                 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
 619         if (!cfg)
 620                 return -ENOMEM;
 621         dev_iommu_priv_set(dev, cfg);
 622
 623         cfg_dart = cfg->stream_maps[0].dart;
 624         if (cfg_dart) {
 625                 if (cfg_dart->supports_bypass != dart->supports_bypass)
 626                         return -EINVAL;
 627                 if (cfg_dart->force_bypass != dart->force_bypass)
 628                         return -EINVAL;
 629                 if (cfg_dart->pgsize != dart->pgsize)
 630                         return -EINVAL;
 631         }
 632
 633         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 634                 if (cfg->stream_maps[i].dart == dart) {
 635                         cfg->stream_maps[i].sidmap |= 1 << sid;
 636                         return 0;
 637                 }
 638         }
 639         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 640                 if (!cfg->stream_maps[i].dart) {
 641                         cfg->stream_maps[i].dart = dart;
 642                         cfg->stream_maps[i].sidmap = 1 << sid;
 643                         return 0;
 644                 }
 645         }
 646
 647         return -EINVAL;
 648 }
 649
 650 static DEFINE_MUTEX(apple_dart_groups_lock);
 651
 652 static void apple_dart_release_group(void *iommu_data)
 653 {
 654         int i, sid;
 655         struct apple_dart_stream_map *stream_map;
 656         struct apple_dart_master_cfg *group_master_cfg = iommu_data;
 657
 658         mutex_lock(&apple_dart_groups_lock);
 659
 660         for_each_stream_map(i, group_master_cfg, stream_map)
 661                 for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 662                         stream_map->dart->sid2group[sid] = NULL;
 663
 664         kfree(iommu_data);
 665         mutex_unlock(&apple_dart_groups_lock);
 666 }
 667
 668 static struct iommu_group *apple_dart_device_group(struct device *dev)
 669 {
 670         int i, sid;
 671         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 672         struct apple_dart_stream_map *stream_map;
 673         struct apple_dart_master_cfg *group_master_cfg;
 674         struct iommu_group *group = NULL;
 675         struct iommu_group *res = ERR_PTR(-EINVAL);
 676
 677         mutex_lock(&apple_dart_groups_lock);
 678
 679         for_each_stream_map(i, cfg, stream_map) {
 680                 for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS) {
 681                         struct iommu_group *stream_group =
 682                                 stream_map->dart->sid2group[sid];
 683
 684                         if (group && group != stream_group) {
 685                                 res = ERR_PTR(-EINVAL);
 686                                 goto out;
 687                         }
 688
 689                         group = stream_group;
 690                 }
 691         }
 692
 693         if (group) {
 694                 res = iommu_group_ref_get(group);
 695                 goto out;
 696         }
 697
 698 #ifdef CONFIG_PCI
 699         if (dev_is_pci(dev))
 700                 group = pci_device_group(dev);
 701         else
 702 #endif
 703                 group = generic_device_group(dev);
 704
 705         res = ERR_PTR(-ENOMEM);
 706         if (!group)
 707                 goto out;
 708
 709         group_master_cfg = kmemdup(cfg, sizeof(*group_master_cfg), GFP_KERNEL);
 710         if (!group_master_cfg) {
 711                 iommu_group_put(group);
 712                 goto out;
 713         }
 714
 715         iommu_group_set_iommudata(group, group_master_cfg,
 716                 apple_dart_release_group);
 717
 718         for_each_stream_map(i, cfg, stream_map)
 719                 for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 720                         stream_map->dart->sid2group[sid] = group;
 721
 722         res = group;
 723
 724 out:
 725         mutex_unlock(&apple_dart_groups_lock);
 726         return res;
 727 }
 728
 729 static int apple_dart_def_domain_type(struct device *dev)
 730 {
 731         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 732
 733         if (cfg->stream_maps[0].dart->force_bypass)
 734                 return IOMMU_DOMAIN_IDENTITY;
 735         if (!cfg->stream_maps[0].dart->supports_bypass)
 736                 return IOMMU_DOMAIN_DMA;
 737
 738         return 0;
 739 }
 740
 741 #ifndef CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR
 742 /* Keep things compiling when CONFIG_PCI_APPLE isn't selected */
 743 #define CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR     0
 744 #endif
 745 #define DOORBELL_ADDR   (CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR & PAGE_MASK)
 746
 747 static void apple_dart_get_resv_regions(struct device *dev,
 748                                         struct list_head *head)
 749 {
 750         if (IS_ENABLED(CONFIG_PCIE_APPLE) && dev_is_pci(dev)) {
 751                 struct iommu_resv_region *region;
 752                 int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
 753
 754                 region = iommu_alloc_resv_region(DOORBELL_ADDR,
 755                                                  PAGE_SIZE, prot,
 756                                                  IOMMU_RESV_MSI);
 757                 if (!region)
 758                         return;
 759
 760                 list_add_tail(&region->list, head);
 761         }
 762
 763         iommu_dma_get_resv_regions(dev, head);
 764 }
 765
 766 static const struct iommu_ops apple_dart_iommu_ops = {
 767         .domain_alloc = apple_dart_domain_alloc,
 768         .probe_device = apple_dart_probe_device,
 769         .release_device = apple_dart_release_device,
 770         .device_group = apple_dart_device_group,
 771         .of_xlate = apple_dart_of_xlate,
 772         .def_domain_type = apple_dart_def_domain_type,
 773         .get_resv_regions = apple_dart_get_resv_regions,
 774         .put_resv_regions = generic_iommu_put_resv_regions,
 775         .pgsize_bitmap = -1UL, /* Restricted during dart probe */
 776         .owner = THIS_MODULE,
 777         .default_domain_ops = &(const struct iommu_domain_ops) {
 778                 .attach_dev     = apple_dart_attach_dev,
 779                 .detach_dev     = apple_dart_detach_dev,
 780                 .map_pages      = apple_dart_map_pages,
 781                 .unmap_pages    = apple_dart_unmap_pages,
 782                 .flush_iotlb_all = apple_dart_flush_iotlb_all,
 783                 .iotlb_sync     = apple_dart_iotlb_sync,
 784                 .iotlb_sync_map = apple_dart_iotlb_sync_map,
 785                 .iova_to_phys   = apple_dart_iova_to_phys,
 786                 .free           = apple_dart_domain_free,
 787         }
 788 };
 789
 790 static irqreturn_t apple_dart_irq(int irq, void *dev)
 791 {
 792         struct apple_dart *dart = dev;
 793         const char *fault_name = NULL;
 794         u32 error = readl(dart->regs + DART_ERROR);
 795         u32 error_code = FIELD_GET(DART_ERROR_CODE, error);
 796         u32 addr_lo = readl(dart->regs + DART_ERROR_ADDR_LO);
 797         u32 addr_hi = readl(dart->regs + DART_ERROR_ADDR_HI);
 798         u64 addr = addr_lo | (((u64)addr_hi) << 32);
 799         u8 stream_idx = FIELD_GET(DART_ERROR_STREAM, error);
 800
 801         if (!(error & DART_ERROR_FLAG))
 802                 return IRQ_NONE;
 803
 804         /* there should only be a single bit set but let's use == to be sure */
 805         if (error_code == DART_ERROR_READ_FAULT)
 806                 fault_name = "READ FAULT";
 807         else if (error_code == DART_ERROR_WRITE_FAULT)
 808                 fault_name = "WRITE FAULT";
 809         else if (error_code == DART_ERROR_NO_PTE)
 810                 fault_name = "NO PTE FOR IOVA";
 811         else if (error_code == DART_ERROR_NO_PMD)
 812                 fault_name = "NO PMD FOR IOVA";
 813         else if (error_code == DART_ERROR_NO_TTBR)
 814                 fault_name = "NO TTBR FOR IOVA";
 815         else
 816                 fault_name = "unknown";
 817
 818         dev_err_ratelimited(
 819                 dart->dev,
 820                 "translation fault: status:0x%x stream:%d code:0x%x (%s) at 0x%llx",
 821                 error, stream_idx, error_code, fault_name, addr);
 822
 823         writel(error, dart->regs + DART_ERROR);
 824         return IRQ_HANDLED;
 825 }
 826
 827 static int apple_dart_set_bus_ops(const struct iommu_ops *ops)
 828 {
 829         int ret;
 830
 831         if (!iommu_present(&platform_bus_type)) {
 832                 ret = bus_set_iommu(&platform_bus_type, ops);
 833                 if (ret)
 834                         return ret;
 835         }
 836 #ifdef CONFIG_PCI
 837         if (!iommu_present(&pci_bus_type)) {
 838                 ret = bus_set_iommu(&pci_bus_type, ops);
 839                 if (ret) {
 840                         bus_set_iommu(&platform_bus_type, NULL);
 841                         return ret;
 842                 }
 843         }
 844 #endif
 845         return 0;
 846 }
 847
 848 static int apple_dart_probe(struct platform_device *pdev)
 849 {
 850         int ret;
 851         u32 dart_params[2];
 852         struct resource *res;
 853         struct apple_dart *dart;
 854         struct device *dev = &pdev->dev;
 855
 856         dart = devm_kzalloc(dev, sizeof(*dart), GFP_KERNEL);
 857         if (!dart)
 858                 return -ENOMEM;
 859
 860         dart->dev = dev;
 861         spin_lock_init(&dart->lock);
 862
 863         dart->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 864         if (IS_ERR(dart->regs))
 865                 return PTR_ERR(dart->regs);
 866
 867         if (resource_size(res) < 0x4000) {
 868                 dev_err(dev, "MMIO region too small (%pr)\n", res);
 869                 return -EINVAL;
 870         }
 871
 872         dart->irq = platform_get_irq(pdev, 0);
 873         if (dart->irq < 0)
 874                 return -ENODEV;
 875
 876         ret = devm_clk_bulk_get_all(dev, &dart->clks);
 877         if (ret < 0)
 878                 return ret;
 879         dart->num_clks = ret;
 880
 881         ret = clk_bulk_prepare_enable(dart->num_clks, dart->clks);
 882         if (ret)
 883                 return ret;
 884
 885         ret = apple_dart_hw_reset(dart);
 886         if (ret)
 887                 goto err_clk_disable;
 888
 889         dart_params[0] = readl(dart->regs + DART_PARAMS1);
 890         dart_params[1] = readl(dart->regs + DART_PARAMS2);
 891         dart->pgsize = 1 << FIELD_GET(DART_PARAMS_PAGE_SHIFT, dart_params[0]);
 892         dart->supports_bypass = dart_params[1] & DART_PARAMS_BYPASS_SUPPORT;
 893         dart->force_bypass = dart->pgsize > PAGE_SIZE;
 894
 895         ret = request_irq(dart->irq, apple_dart_irq, IRQF_SHARED,
 896                           "apple-dart fault handler", dart);
 897         if (ret)
 898                 goto err_clk_disable;
 899
 900         platform_set_drvdata(pdev, dart);
 901
 902         ret = apple_dart_set_bus_ops(&apple_dart_iommu_ops);
 903         if (ret)
 904                 goto err_free_irq;
 905
 906         ret = iommu_device_sysfs_add(&dart->iommu, dev, NULL, "apple-dart.%s",
 907                                      dev_name(&pdev->dev));
 908         if (ret)
 909                 goto err_remove_bus_ops;
 910
 911         ret = iommu_device_register(&dart->iommu, &apple_dart_iommu_ops, dev);
 912         if (ret)
 913                 goto err_sysfs_remove;
 914
 915         dev_info(
 916                 &pdev->dev,
 917                 "DART [pagesize %x, bypass support: %d, bypass forced: %d] initialized\n",
 918                 dart->pgsize, dart->supports_bypass, dart->force_bypass);
 919         return 0;
 920
 921 err_sysfs_remove:
 922         iommu_device_sysfs_remove(&dart->iommu);
 923 err_remove_bus_ops:
 924         apple_dart_set_bus_ops(NULL);
 925 err_free_irq:
 926         free_irq(dart->irq, dart);
 927 err_clk_disable:
 928         clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
 929
 930         return ret;
 931 }
 932
 933 static int apple_dart_remove(struct platform_device *pdev)
 934 {
 935         struct apple_dart *dart = platform_get_drvdata(pdev);
 936
 937         apple_dart_hw_reset(dart);
 938         free_irq(dart->irq, dart);
 939         apple_dart_set_bus_ops(NULL);
 940
 941         iommu_device_unregister(&dart->iommu);
 942         iommu_device_sysfs_remove(&dart->iommu);
 943
 944         clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
 945
 946         return 0;
 947 }
 948
 949 static const struct of_device_id apple_dart_of_match[] = {
 950         { .compatible = "apple,t8103-dart", .data = NULL },
 951         {},
 952 };
 953 MODULE_DEVICE_TABLE(of, apple_dart_of_match);
 954
 955 static struct platform_driver apple_dart_driver = {
 956         .driver = {
 957                 .name                   = "apple-dart",
 958                 .of_match_table         = apple_dart_of_match,
 959                 .suppress_bind_attrs    = true,
 960         },
 961         .probe  = apple_dart_probe,
 962         .remove = apple_dart_remove,
 963 };
 964
 965 module_platform_driver(apple_dart_driver);
 966
 967 MODULE_DESCRIPTION("IOMMU API for Apple's DART");
 968 MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
 969 MODULE_LICENSE("GPL v2");