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-mapping.h>
  19 #include <linux/err.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/io-pgtable.h>
  22 #include <linux/iommu.h>
  23 #include <linux/iopoll.h>
  24 #include <linux/module.h>
  25 #include <linux/of.h>
  26 #include <linux/of_address.h>
  27 #include <linux/of_iommu.h>
  28 #include <linux/of_platform.h>
  29 #include <linux/pci.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/slab.h>
  32 #include <linux/swab.h>
  33 #include <linux/types.h>
  34
  35 #include "dma-iommu.h"
  36
  37 #define DART_MAX_STREAMS 16
  38 #define DART_MAX_TTBR 4
  39 #define MAX_DARTS_PER_DEVICE 2
  40
  41 #define DART_STREAM_ALL 0xffff
  42
  43 #define DART_PARAMS1 0x00
  44 #define DART_PARAMS_PAGE_SHIFT GENMASK(27, 24)
  45
  46 #define DART_PARAMS2 0x04
  47 #define DART_PARAMS_BYPASS_SUPPORT BIT(0)
  48
  49 #define DART_STREAM_COMMAND 0x20
  50 #define DART_STREAM_COMMAND_BUSY BIT(2)
  51 #define DART_STREAM_COMMAND_INVALIDATE BIT(20)
  52
  53 #define DART_STREAM_SELECT 0x34
  54
  55 #define DART_ERROR 0x40
  56 #define DART_ERROR_STREAM GENMASK(27, 24)
  57 #define DART_ERROR_CODE GENMASK(11, 0)
  58 #define DART_ERROR_FLAG BIT(31)
  59
  60 #define DART_ERROR_READ_FAULT BIT(4)
  61 #define DART_ERROR_WRITE_FAULT BIT(3)
  62 #define DART_ERROR_NO_PTE BIT(2)
  63 #define DART_ERROR_NO_PMD BIT(1)
  64 #define DART_ERROR_NO_TTBR BIT(0)
  65
  66 #define DART_CONFIG 0x60
  67 #define DART_CONFIG_LOCK BIT(15)
  68
  69 #define DART_STREAM_COMMAND_BUSY_TIMEOUT 100
  70
  71 #define DART_ERROR_ADDR_HI 0x54
  72 #define DART_ERROR_ADDR_LO 0x50
  73
  74 #define DART_STREAMS_ENABLE 0xfc
  75
  76 #define DART_TCR(sid) (0x100 + 4 * (sid))
  77 #define DART_TCR_TRANSLATE_ENABLE BIT(7)
  78 #define DART_TCR_BYPASS0_ENABLE BIT(8)
  79 #define DART_TCR_BYPASS1_ENABLE BIT(12)
  80
  81 #define DART_TTBR(sid, idx) (0x200 + 16 * (sid) + 4 * (idx))
  82 #define DART_TTBR_VALID BIT(31)
  83 #define DART_TTBR_SHIFT 12
  84
  85 struct apple_dart_hw {
  86         u32 oas;
  87         enum io_pgtable_fmt fmt;
  88 };
  89
  90 /*
  91  * Private structure associated with each DART device.
  92  *
  93  * @dev: device struct
  94  * @hw: SoC-specific hardware data
  95  * @regs: mapped MMIO region
  96  * @irq: interrupt number, can be shared with other DARTs
  97  * @clks: clocks associated with this DART
  98  * @num_clks: number of @clks
  99  * @lock: lock for hardware operations involving this dart
 100  * @pgsize: pagesize supported by this DART
 101  * @supports_bypass: indicates if this DART supports bypass mode
 102  * @force_bypass: force bypass mode due to pagesize mismatch?
 103  * @sid2group: maps stream ids to iommu_groups
 104  * @iommu: iommu core device
 105  */
 106 struct apple_dart {
 107         struct device *dev;
 108         const struct apple_dart_hw *hw;
 109
 110         void __iomem *regs;
 111
 112         int irq;
 113         struct clk_bulk_data *clks;
 114         int num_clks;
 115
 116         spinlock_t lock;
 117
 118         u32 pgsize;
 119         u32 supports_bypass : 1;
 120         u32 force_bypass : 1;
 121
 122         struct iommu_group *sid2group[DART_MAX_STREAMS];
 123         struct iommu_device iommu;
 124 };
 125
 126 /*
 127  * Convenience struct to identify streams.
 128  *
 129  * The normal variant is used inside apple_dart_master_cfg which isn't written
 130  * to concurrently.
 131  * The atomic variant is used inside apple_dart_domain where we have to guard
 132  * against races from potential parallel calls to attach/detach_device.
 133  * Note that even inside the atomic variant the apple_dart pointer is not
 134  * protected: This pointer is initialized once under the domain init mutex
 135  * and never changed again afterwards. Devices with different dart pointers
 136  * cannot be attached to the same domain.
 137  *
 138  * @dart dart pointer
 139  * @sid stream id bitmap
 140  */
 141 struct apple_dart_stream_map {
 142         struct apple_dart *dart;
 143         unsigned long sidmap;
 144 };
 145 struct apple_dart_atomic_stream_map {
 146         struct apple_dart *dart;
 147         atomic64_t sidmap;
 148 };
 149
 150 /*
 151  * This structure is attached to each iommu domain handled by a DART.
 152  *
 153  * @pgtbl_ops: pagetable ops allocated by io-pgtable
 154  * @finalized: true if the domain has been completely initialized
 155  * @init_lock: protects domain initialization
 156  * @stream_maps: streams attached to this domain (valid for DMA/UNMANAGED only)
 157  * @domain: core iommu domain pointer
 158  */
 159 struct apple_dart_domain {
 160         struct io_pgtable_ops *pgtbl_ops;
 161
 162         bool finalized;
 163         struct mutex init_lock;
 164         struct apple_dart_atomic_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
 165
 166         struct iommu_domain domain;
 167 };
 168
 169 /*
 170  * This structure is attached to devices with dev_iommu_priv_set() on of_xlate
 171  * and contains a list of streams bound to this device.
 172  * So far the worst case seen is a single device with two streams
 173  * from different darts, such that this simple static array is enough.
 174  *
 175  * @streams: streams for this device
 176  */
 177 struct apple_dart_master_cfg {
 178         struct apple_dart_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
 179 };
 180
 181 /*
 182  * Helper macro to iterate over apple_dart_master_cfg.stream_maps and
 183  * apple_dart_domain.stream_maps
 184  *
 185  * @i int used as loop variable
 186  * @base pointer to base struct (apple_dart_master_cfg or apple_dart_domain)
 187  * @stream pointer to the apple_dart_streams struct for each loop iteration
 188  */
 189 #define for_each_stream_map(i, base, stream_map)                               \
 190         for (i = 0, stream_map = &(base)->stream_maps[0];                      \
 191              i < MAX_DARTS_PER_DEVICE && stream_map->dart;                     \
 192              stream_map = &(base)->stream_maps[++i])
 193
 194 static struct platform_driver apple_dart_driver;
 195 static const struct iommu_ops apple_dart_iommu_ops;
 196
 197 static struct apple_dart_domain *to_dart_domain(struct iommu_domain *dom)
 198 {
 199         return container_of(dom, struct apple_dart_domain, domain);
 200 }
 201
 202 static void
 203 apple_dart_hw_enable_translation(struct apple_dart_stream_map *stream_map)
 204 {
 205         int sid;
 206
 207         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 208                 writel(DART_TCR_TRANSLATE_ENABLE,
 209                        stream_map->dart->regs + DART_TCR(sid));
 210 }
 211
 212 static void apple_dart_hw_disable_dma(struct apple_dart_stream_map *stream_map)
 213 {
 214         int sid;
 215
 216         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 217                 writel(0, stream_map->dart->regs + DART_TCR(sid));
 218 }
 219
 220 static void
 221 apple_dart_hw_enable_bypass(struct apple_dart_stream_map *stream_map)
 222 {
 223         int sid;
 224
 225         WARN_ON(!stream_map->dart->supports_bypass);
 226         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 227                 writel(DART_TCR_BYPASS0_ENABLE | DART_TCR_BYPASS1_ENABLE,
 228                        stream_map->dart->regs + DART_TCR(sid));
 229 }
 230
 231 static void apple_dart_hw_set_ttbr(struct apple_dart_stream_map *stream_map,
 232                                    u8 idx, phys_addr_t paddr)
 233 {
 234         int sid;
 235
 236         WARN_ON(paddr & ((1 << DART_TTBR_SHIFT) - 1));
 237         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 238                 writel(DART_TTBR_VALID | (paddr >> DART_TTBR_SHIFT),
 239                        stream_map->dart->regs + DART_TTBR(sid, idx));
 240 }
 241
 242 static void apple_dart_hw_clear_ttbr(struct apple_dart_stream_map *stream_map,
 243                                      u8 idx)
 244 {
 245         int sid;
 246
 247         for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 248                 writel(0, stream_map->dart->regs + DART_TTBR(sid, idx));
 249 }
 250
 251 static void
 252 apple_dart_hw_clear_all_ttbrs(struct apple_dart_stream_map *stream_map)
 253 {
 254         int i;
 255
 256         for (i = 0; i < DART_MAX_TTBR; ++i)
 257                 apple_dart_hw_clear_ttbr(stream_map, i);
 258 }
 259
 260 static int
 261 apple_dart_hw_stream_command(struct apple_dart_stream_map *stream_map,
 262                              u32 command)
 263 {
 264         unsigned long flags;
 265         int ret;
 266         u32 command_reg;
 267
 268         spin_lock_irqsave(&stream_map->dart->lock, flags);
 269
 270         writel(stream_map->sidmap, stream_map->dart->regs + DART_STREAM_SELECT);
 271         writel(command, stream_map->dart->regs + DART_STREAM_COMMAND);
 272
 273         ret = readl_poll_timeout_atomic(
 274                 stream_map->dart->regs + DART_STREAM_COMMAND, command_reg,
 275                 !(command_reg & DART_STREAM_COMMAND_BUSY), 1,
 276                 DART_STREAM_COMMAND_BUSY_TIMEOUT);
 277
 278         spin_unlock_irqrestore(&stream_map->dart->lock, flags);
 279
 280         if (ret) {
 281                 dev_err(stream_map->dart->dev,
 282                         "busy bit did not clear after command %x for streams %lx\n",
 283                         command, stream_map->sidmap);
 284                 return ret;
 285         }
 286
 287         return 0;
 288 }
 289
 290 static int
 291 apple_dart_hw_invalidate_tlb(struct apple_dart_stream_map *stream_map)
 292 {
 293         return apple_dart_hw_stream_command(stream_map,
 294                                             DART_STREAM_COMMAND_INVALIDATE);
 295 }
 296
 297 static int apple_dart_hw_reset(struct apple_dart *dart)
 298 {
 299         u32 config;
 300         struct apple_dart_stream_map stream_map;
 301
 302         config = readl(dart->regs + DART_CONFIG);
 303         if (config & DART_CONFIG_LOCK) {
 304                 dev_err(dart->dev, "DART is locked down until reboot: %08x\n",
 305                         config);
 306                 return -EINVAL;
 307         }
 308
 309         stream_map.dart = dart;
 310         stream_map.sidmap = DART_STREAM_ALL;
 311         apple_dart_hw_disable_dma(&stream_map);
 312         apple_dart_hw_clear_all_ttbrs(&stream_map);
 313
 314         /* enable all streams globally since TCR is used to control isolation */
 315         writel(DART_STREAM_ALL, dart->regs + DART_STREAMS_ENABLE);
 316
 317         /* clear any pending errors before the interrupt is unmasked */
 318         writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR);
 319
 320         return apple_dart_hw_invalidate_tlb(&stream_map);
 321 }
 322
 323 static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain)
 324 {
 325         int i;
 326         struct apple_dart_atomic_stream_map *domain_stream_map;
 327         struct apple_dart_stream_map stream_map;
 328
 329         for_each_stream_map(i, domain, domain_stream_map) {
 330                 stream_map.dart = domain_stream_map->dart;
 331                 stream_map.sidmap = atomic64_read(&domain_stream_map->sidmap);
 332                 apple_dart_hw_invalidate_tlb(&stream_map);
 333         }
 334 }
 335
 336 static void apple_dart_flush_iotlb_all(struct iommu_domain *domain)
 337 {
 338         apple_dart_domain_flush_tlb(to_dart_domain(domain));
 339 }
 340
 341 static void apple_dart_iotlb_sync(struct iommu_domain *domain,
 342                                   struct iommu_iotlb_gather *gather)
 343 {
 344         apple_dart_domain_flush_tlb(to_dart_domain(domain));
 345 }
 346
 347 static void apple_dart_iotlb_sync_map(struct iommu_domain *domain,
 348                                       unsigned long iova, size_t size)
 349 {
 350         apple_dart_domain_flush_tlb(to_dart_domain(domain));
 351 }
 352
 353 static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain,
 354                                            dma_addr_t iova)
 355 {
 356         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 357         struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
 358
 359         if (!ops)
 360                 return 0;
 361
 362         return ops->iova_to_phys(ops, iova);
 363 }
 364
 365 static int apple_dart_map_pages(struct iommu_domain *domain, unsigned long iova,
 366                                 phys_addr_t paddr, size_t pgsize,
 367                                 size_t pgcount, int prot, gfp_t gfp,
 368                                 size_t *mapped)
 369 {
 370         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 371         struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
 372
 373         if (!ops)
 374                 return -ENODEV;
 375
 376         return ops->map_pages(ops, iova, paddr, pgsize, pgcount, prot, gfp,
 377                               mapped);
 378 }
 379
 380 static size_t apple_dart_unmap_pages(struct iommu_domain *domain,
 381                                      unsigned long iova, size_t pgsize,
 382                                      size_t pgcount,
 383                                      struct iommu_iotlb_gather *gather)
 384 {
 385         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 386         struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
 387
 388         return ops->unmap_pages(ops, iova, pgsize, pgcount, gather);
 389 }
 390
 391 static void
 392 apple_dart_setup_translation(struct apple_dart_domain *domain,
 393                              struct apple_dart_stream_map *stream_map)
 394 {
 395         int i;
 396         struct io_pgtable_cfg *pgtbl_cfg =
 397                 &io_pgtable_ops_to_pgtable(domain->pgtbl_ops)->cfg;
 398
 399         for (i = 0; i < pgtbl_cfg->apple_dart_cfg.n_ttbrs; ++i)
 400                 apple_dart_hw_set_ttbr(stream_map, i,
 401                                        pgtbl_cfg->apple_dart_cfg.ttbr[i]);
 402         for (; i < DART_MAX_TTBR; ++i)
 403                 apple_dart_hw_clear_ttbr(stream_map, i);
 404
 405         apple_dart_hw_enable_translation(stream_map);
 406         apple_dart_hw_invalidate_tlb(stream_map);
 407 }
 408
 409 static int apple_dart_finalize_domain(struct iommu_domain *domain,
 410                                       struct apple_dart_master_cfg *cfg)
 411 {
 412         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 413         struct apple_dart *dart = cfg->stream_maps[0].dart;
 414         struct io_pgtable_cfg pgtbl_cfg;
 415         int ret = 0;
 416         int i;
 417
 418         mutex_lock(&dart_domain->init_lock);
 419
 420         if (dart_domain->finalized)
 421                 goto done;
 422
 423         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 424                 dart_domain->stream_maps[i].dart = cfg->stream_maps[i].dart;
 425                 atomic64_set(&dart_domain->stream_maps[i].sidmap,
 426                              cfg->stream_maps[i].sidmap);
 427         }
 428
 429         pgtbl_cfg = (struct io_pgtable_cfg){
 430                 .pgsize_bitmap = dart->pgsize,
 431                 .ias = 32,
 432                 .oas = dart->hw->oas,
 433                 .coherent_walk = 1,
 434                 .iommu_dev = dart->dev,
 435         };
 436
 437         dart_domain->pgtbl_ops =
 438                 alloc_io_pgtable_ops(dart->hw->fmt, &pgtbl_cfg, domain);
 439         if (!dart_domain->pgtbl_ops) {
 440                 ret = -ENOMEM;
 441                 goto done;
 442         }
 443
 444         domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap;
 445         domain->geometry.aperture_start = 0;
 446         domain->geometry.aperture_end = DMA_BIT_MASK(32);
 447         domain->geometry.force_aperture = true;
 448
 449         dart_domain->finalized = true;
 450
 451 done:
 452         mutex_unlock(&dart_domain->init_lock);
 453         return ret;
 454 }
 455
 456 static int
 457 apple_dart_mod_streams(struct apple_dart_atomic_stream_map *domain_maps,
 458                        struct apple_dart_stream_map *master_maps,
 459                        bool add_streams)
 460 {
 461         int i;
 462
 463         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 464                 if (domain_maps[i].dart != master_maps[i].dart)
 465                         return -EINVAL;
 466         }
 467
 468         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 469                 if (!domain_maps[i].dart)
 470                         break;
 471                 if (add_streams)
 472                         atomic64_or(master_maps[i].sidmap,
 473                                     &domain_maps[i].sidmap);
 474                 else
 475                         atomic64_and(~master_maps[i].sidmap,
 476                                      &domain_maps[i].sidmap);
 477         }
 478
 479         return 0;
 480 }
 481
 482 static int apple_dart_domain_add_streams(struct apple_dart_domain *domain,
 483                                          struct apple_dart_master_cfg *cfg)
 484 {
 485         return apple_dart_mod_streams(domain->stream_maps, cfg->stream_maps,
 486                                       true);
 487 }
 488
 489 static int apple_dart_domain_remove_streams(struct apple_dart_domain *domain,
 490                                             struct apple_dart_master_cfg *cfg)
 491 {
 492         return apple_dart_mod_streams(domain->stream_maps, cfg->stream_maps,
 493                                       false);
 494 }
 495
 496 static int apple_dart_attach_dev(struct iommu_domain *domain,
 497                                  struct device *dev)
 498 {
 499         int ret, i;
 500         struct apple_dart_stream_map *stream_map;
 501         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 502         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 503
 504         if (cfg->stream_maps[0].dart->force_bypass &&
 505             domain->type != IOMMU_DOMAIN_IDENTITY)
 506                 return -EINVAL;
 507         if (!cfg->stream_maps[0].dart->supports_bypass &&
 508             domain->type == IOMMU_DOMAIN_IDENTITY)
 509                 return -EINVAL;
 510
 511         ret = apple_dart_finalize_domain(domain, cfg);
 512         if (ret)
 513                 return ret;
 514
 515         switch (domain->type) {
 516         case IOMMU_DOMAIN_DMA:
 517         case IOMMU_DOMAIN_UNMANAGED:
 518                 ret = apple_dart_domain_add_streams(dart_domain, cfg);
 519                 if (ret)
 520                         return ret;
 521
 522                 for_each_stream_map(i, cfg, stream_map)
 523                         apple_dart_setup_translation(dart_domain, stream_map);
 524                 break;
 525         case IOMMU_DOMAIN_BLOCKED:
 526                 for_each_stream_map(i, cfg, stream_map)
 527                         apple_dart_hw_disable_dma(stream_map);
 528                 break;
 529         case IOMMU_DOMAIN_IDENTITY:
 530                 for_each_stream_map(i, cfg, stream_map)
 531                         apple_dart_hw_enable_bypass(stream_map);
 532                 break;
 533         }
 534
 535         return ret;
 536 }
 537
 538 static void apple_dart_detach_dev(struct iommu_domain *domain,
 539                                   struct device *dev)
 540 {
 541         int i;
 542         struct apple_dart_stream_map *stream_map;
 543         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 544         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 545
 546         for_each_stream_map(i, cfg, stream_map)
 547                 apple_dart_hw_disable_dma(stream_map);
 548
 549         if (domain->type == IOMMU_DOMAIN_DMA ||
 550             domain->type == IOMMU_DOMAIN_UNMANAGED)
 551                 apple_dart_domain_remove_streams(dart_domain, cfg);
 552 }
 553
 554 static struct iommu_device *apple_dart_probe_device(struct device *dev)
 555 {
 556         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 557         struct apple_dart_stream_map *stream_map;
 558         int i;
 559
 560         if (!cfg)
 561                 return ERR_PTR(-ENODEV);
 562
 563         for_each_stream_map(i, cfg, stream_map)
 564                 device_link_add(
 565                         dev, stream_map->dart->dev,
 566                         DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER);
 567
 568         return &cfg->stream_maps[0].dart->iommu;
 569 }
 570
 571 static void apple_dart_release_device(struct device *dev)
 572 {
 573         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 574
 575         dev_iommu_priv_set(dev, NULL);
 576         kfree(cfg);
 577 }
 578
 579 static struct iommu_domain *apple_dart_domain_alloc(unsigned int type)
 580 {
 581         struct apple_dart_domain *dart_domain;
 582
 583         if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED &&
 584             type != IOMMU_DOMAIN_IDENTITY && type != IOMMU_DOMAIN_BLOCKED)
 585                 return NULL;
 586
 587         dart_domain = kzalloc(sizeof(*dart_domain), GFP_KERNEL);
 588         if (!dart_domain)
 589                 return NULL;
 590
 591         mutex_init(&dart_domain->init_lock);
 592
 593         /* no need to allocate pgtbl_ops or do any other finalization steps */
 594         if (type == IOMMU_DOMAIN_IDENTITY || type == IOMMU_DOMAIN_BLOCKED)
 595                 dart_domain->finalized = true;
 596
 597         return &dart_domain->domain;
 598 }
 599
 600 static void apple_dart_domain_free(struct iommu_domain *domain)
 601 {
 602         struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 603
 604         if (dart_domain->pgtbl_ops)
 605                 free_io_pgtable_ops(dart_domain->pgtbl_ops);
 606
 607         kfree(dart_domain);
 608 }
 609
 610 static int apple_dart_of_xlate(struct device *dev, struct of_phandle_args *args)
 611 {
 612         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 613         struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
 614         struct apple_dart *dart = platform_get_drvdata(iommu_pdev);
 615         struct apple_dart *cfg_dart;
 616         int i, sid;
 617
 618         if (args->args_count != 1)
 619                 return -EINVAL;
 620         sid = args->args[0];
 621
 622         if (!cfg)
 623                 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
 624         if (!cfg)
 625                 return -ENOMEM;
 626         dev_iommu_priv_set(dev, cfg);
 627
 628         cfg_dart = cfg->stream_maps[0].dart;
 629         if (cfg_dart) {
 630                 if (cfg_dart->supports_bypass != dart->supports_bypass)
 631                         return -EINVAL;
 632                 if (cfg_dart->force_bypass != dart->force_bypass)
 633                         return -EINVAL;
 634                 if (cfg_dart->pgsize != dart->pgsize)
 635                         return -EINVAL;
 636         }
 637
 638         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 639                 if (cfg->stream_maps[i].dart == dart) {
 640                         cfg->stream_maps[i].sidmap |= 1 << sid;
 641                         return 0;
 642                 }
 643         }
 644         for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 645                 if (!cfg->stream_maps[i].dart) {
 646                         cfg->stream_maps[i].dart = dart;
 647                         cfg->stream_maps[i].sidmap = 1 << sid;
 648                         return 0;
 649                 }
 650         }
 651
 652         return -EINVAL;
 653 }
 654
 655 static DEFINE_MUTEX(apple_dart_groups_lock);
 656
 657 static void apple_dart_release_group(void *iommu_data)
 658 {
 659         int i, sid;
 660         struct apple_dart_stream_map *stream_map;
 661         struct apple_dart_master_cfg *group_master_cfg = iommu_data;
 662
 663         mutex_lock(&apple_dart_groups_lock);
 664
 665         for_each_stream_map(i, group_master_cfg, stream_map)
 666                 for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 667                         stream_map->dart->sid2group[sid] = NULL;
 668
 669         kfree(iommu_data);
 670         mutex_unlock(&apple_dart_groups_lock);
 671 }
 672
 673 static struct iommu_group *apple_dart_device_group(struct device *dev)
 674 {
 675         int i, sid;
 676         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 677         struct apple_dart_stream_map *stream_map;
 678         struct apple_dart_master_cfg *group_master_cfg;
 679         struct iommu_group *group = NULL;
 680         struct iommu_group *res = ERR_PTR(-EINVAL);
 681
 682         mutex_lock(&apple_dart_groups_lock);
 683
 684         for_each_stream_map(i, cfg, stream_map) {
 685                 for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS) {
 686                         struct iommu_group *stream_group =
 687                                 stream_map->dart->sid2group[sid];
 688
 689                         if (group && group != stream_group) {
 690                                 res = ERR_PTR(-EINVAL);
 691                                 goto out;
 692                         }
 693
 694                         group = stream_group;
 695                 }
 696         }
 697
 698         if (group) {
 699                 res = iommu_group_ref_get(group);
 700                 goto out;
 701         }
 702
 703 #ifdef CONFIG_PCI
 704         if (dev_is_pci(dev))
 705                 group = pci_device_group(dev);
 706         else
 707 #endif
 708                 group = generic_device_group(dev);
 709
 710         res = ERR_PTR(-ENOMEM);
 711         if (!group)
 712                 goto out;
 713
 714         group_master_cfg = kmemdup(cfg, sizeof(*group_master_cfg), GFP_KERNEL);
 715         if (!group_master_cfg) {
 716                 iommu_group_put(group);
 717                 goto out;
 718         }
 719
 720         iommu_group_set_iommudata(group, group_master_cfg,
 721                 apple_dart_release_group);
 722
 723         for_each_stream_map(i, cfg, stream_map)
 724                 for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
 725                         stream_map->dart->sid2group[sid] = group;
 726
 727         res = group;
 728
 729 out:
 730         mutex_unlock(&apple_dart_groups_lock);
 731         return res;
 732 }
 733
 734 static int apple_dart_def_domain_type(struct device *dev)
 735 {
 736         struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 737
 738         if (cfg->stream_maps[0].dart->force_bypass)
 739                 return IOMMU_DOMAIN_IDENTITY;
 740         if (!cfg->stream_maps[0].dart->supports_bypass)
 741                 return IOMMU_DOMAIN_DMA;
 742
 743         return 0;
 744 }
 745
 746 #ifndef CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR
 747 /* Keep things compiling when CONFIG_PCI_APPLE isn't selected */
 748 #define CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR     0
 749 #endif
 750 #define DOORBELL_ADDR   (CONFIG_PCIE_APPLE_MSI_DOORBELL_ADDR & PAGE_MASK)
 751
 752 static void apple_dart_get_resv_regions(struct device *dev,
 753                                         struct list_head *head)
 754 {
 755         if (IS_ENABLED(CONFIG_PCIE_APPLE) && dev_is_pci(dev)) {
 756                 struct iommu_resv_region *region;
 757                 int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
 758
 759                 region = iommu_alloc_resv_region(DOORBELL_ADDR,
 760                                                  PAGE_SIZE, prot,
 761                                                  IOMMU_RESV_MSI, GFP_KERNEL);
 762                 if (!region)
 763                         return;
 764
 765                 list_add_tail(&region->list, head);
 766         }
 767
 768         iommu_dma_get_resv_regions(dev, head);
 769 }
 770
 771 static const struct iommu_ops apple_dart_iommu_ops = {
 772         .domain_alloc = apple_dart_domain_alloc,
 773         .probe_device = apple_dart_probe_device,
 774         .release_device = apple_dart_release_device,
 775         .device_group = apple_dart_device_group,
 776         .of_xlate = apple_dart_of_xlate,
 777         .def_domain_type = apple_dart_def_domain_type,
 778         .get_resv_regions = apple_dart_get_resv_regions,
 779         .pgsize_bitmap = -1UL, /* Restricted during dart probe */
 780         .owner = THIS_MODULE,
 781         .default_domain_ops = &(const struct iommu_domain_ops) {
 782                 .attach_dev     = apple_dart_attach_dev,
 783                 .detach_dev     = apple_dart_detach_dev,
 784                 .map_pages      = apple_dart_map_pages,
 785                 .unmap_pages    = apple_dart_unmap_pages,
 786                 .flush_iotlb_all = apple_dart_flush_iotlb_all,
 787                 .iotlb_sync     = apple_dart_iotlb_sync,
 788                 .iotlb_sync_map = apple_dart_iotlb_sync_map,
 789                 .iova_to_phys   = apple_dart_iova_to_phys,
 790                 .free           = apple_dart_domain_free,
 791         }
 792 };
 793
 794 static irqreturn_t apple_dart_irq(int irq, void *dev)
 795 {
 796         struct apple_dart *dart = dev;
 797         const char *fault_name = NULL;
 798         u32 error = readl(dart->regs + DART_ERROR);
 799         u32 error_code = FIELD_GET(DART_ERROR_CODE, error);
 800         u32 addr_lo = readl(dart->regs + DART_ERROR_ADDR_LO);
 801         u32 addr_hi = readl(dart->regs + DART_ERROR_ADDR_HI);
 802         u64 addr = addr_lo | (((u64)addr_hi) << 32);
 803         u8 stream_idx = FIELD_GET(DART_ERROR_STREAM, error);
 804
 805         if (!(error & DART_ERROR_FLAG))
 806                 return IRQ_NONE;
 807
 808         /* there should only be a single bit set but let's use == to be sure */
 809         if (error_code == DART_ERROR_READ_FAULT)
 810                 fault_name = "READ FAULT";
 811         else if (error_code == DART_ERROR_WRITE_FAULT)
 812                 fault_name = "WRITE FAULT";
 813         else if (error_code == DART_ERROR_NO_PTE)
 814                 fault_name = "NO PTE FOR IOVA";
 815         else if (error_code == DART_ERROR_NO_PMD)
 816                 fault_name = "NO PMD FOR IOVA";
 817         else if (error_code == DART_ERROR_NO_TTBR)
 818                 fault_name = "NO TTBR FOR IOVA";
 819         else
 820                 fault_name = "unknown";
 821
 822         dev_err_ratelimited(
 823                 dart->dev,
 824                 "translation fault: status:0x%x stream:%d code:0x%x (%s) at 0x%llx",
 825                 error, stream_idx, error_code, fault_name, addr);
 826
 827         writel(error, dart->regs + DART_ERROR);
 828         return IRQ_HANDLED;
 829 }
 830
 831 static int apple_dart_probe(struct platform_device *pdev)
 832 {
 833         int ret;
 834         u32 dart_params[2];
 835         struct resource *res;
 836         struct apple_dart *dart;
 837         struct device *dev = &pdev->dev;
 838
 839         dart = devm_kzalloc(dev, sizeof(*dart), GFP_KERNEL);
 840         if (!dart)
 841                 return -ENOMEM;
 842
 843         dart->dev = dev;
 844         dart->hw = of_device_get_match_data(dev);
 845         spin_lock_init(&dart->lock);
 846
 847         dart->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 848         if (IS_ERR(dart->regs))
 849                 return PTR_ERR(dart->regs);
 850
 851         if (resource_size(res) < 0x4000) {
 852                 dev_err(dev, "MMIO region too small (%pr)\n", res);
 853                 return -EINVAL;
 854         }
 855
 856         dart->irq = platform_get_irq(pdev, 0);
 857         if (dart->irq < 0)
 858                 return -ENODEV;
 859
 860         ret = devm_clk_bulk_get_all(dev, &dart->clks);
 861         if (ret < 0)
 862                 return ret;
 863         dart->num_clks = ret;
 864
 865         ret = clk_bulk_prepare_enable(dart->num_clks, dart->clks);
 866         if (ret)
 867                 return ret;
 868
 869         ret = apple_dart_hw_reset(dart);
 870         if (ret)
 871                 goto err_clk_disable;
 872
 873         dart_params[0] = readl(dart->regs + DART_PARAMS1);
 874         dart_params[1] = readl(dart->regs + DART_PARAMS2);
 875         dart->pgsize = 1 << FIELD_GET(DART_PARAMS_PAGE_SHIFT, dart_params[0]);
 876         dart->supports_bypass = dart_params[1] & DART_PARAMS_BYPASS_SUPPORT;
 877         dart->force_bypass = dart->pgsize > PAGE_SIZE;
 878
 879         ret = request_irq(dart->irq, apple_dart_irq, IRQF_SHARED,
 880                           "apple-dart fault handler", dart);
 881         if (ret)
 882                 goto err_clk_disable;
 883
 884         platform_set_drvdata(pdev, dart);
 885
 886         ret = iommu_device_sysfs_add(&dart->iommu, dev, NULL, "apple-dart.%s",
 887                                      dev_name(&pdev->dev));
 888         if (ret)
 889                 goto err_free_irq;
 890
 891         ret = iommu_device_register(&dart->iommu, &apple_dart_iommu_ops, dev);
 892         if (ret)
 893                 goto err_sysfs_remove;
 894
 895         dev_info(
 896                 &pdev->dev,
 897                 "DART [pagesize %x, bypass support: %d, bypass forced: %d] initialized\n",
 898                 dart->pgsize, dart->supports_bypass, dart->force_bypass);
 899         return 0;
 900
 901 err_sysfs_remove:
 902         iommu_device_sysfs_remove(&dart->iommu);
 903 err_free_irq:
 904         free_irq(dart->irq, dart);
 905 err_clk_disable:
 906         clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
 907
 908         return ret;
 909 }
 910
 911 static int apple_dart_remove(struct platform_device *pdev)
 912 {
 913         struct apple_dart *dart = platform_get_drvdata(pdev);
 914
 915         apple_dart_hw_reset(dart);
 916         free_irq(dart->irq, dart);
 917
 918         iommu_device_unregister(&dart->iommu);
 919         iommu_device_sysfs_remove(&dart->iommu);
 920
 921         clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
 922
 923         return 0;
 924 }
 925
 926 static const struct apple_dart_hw apple_dart_hw_t8103 = {
 927         .oas = 36,
 928         .fmt = APPLE_DART,
 929 };
 930 static const struct apple_dart_hw apple_dart_hw_t6000 = {
 931         .oas = 42,
 932         .fmt = APPLE_DART2,
 933 };
 934
 935 static const struct of_device_id apple_dart_of_match[] = {
 936         { .compatible = "apple,t8103-dart", .data = &apple_dart_hw_t8103 },
 937         { .compatible = "apple,t6000-dart", .data = &apple_dart_hw_t6000 },
 938         {},
 939 };
 940 MODULE_DEVICE_TABLE(of, apple_dart_of_match);
 941
 942 static struct platform_driver apple_dart_driver = {
 943         .driver = {
 944                 .name                   = "apple-dart",
 945                 .of_match_table         = apple_dart_of_match,
 946                 .suppress_bind_attrs    = true,
 947         },
 948         .probe  = apple_dart_probe,
 949         .remove = apple_dart_remove,
 950 };
 951
 952 module_platform_driver(apple_dart_driver);
 953
 954 MODULE_DESCRIPTION("IOMMU API for Apple's DART");
 955 MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
 956 MODULE_LICENSE("GPL v2");