drivers/iommu/tegra-smmu.c

   1 /*
   2  * Copyright (C) 2011-2014 NVIDIA CORPORATION.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/bitops.h>
  10 #include <linux/debugfs.h>
  11 #include <linux/err.h>
  12 #include <linux/iommu.h>
  13 #include <linux/kernel.h>
  14 #include <linux/of.h>
  15 #include <linux/of_device.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18 #include <linux/dma-mapping.h>
  19
  20 #include <soc/tegra/ahb.h>
  21 #include <soc/tegra/mc.h>
  22
  23 struct tegra_smmu_group {
  24         struct list_head list;
  25         const struct tegra_smmu_group_soc *soc;
  26         struct iommu_group *group;
  27 };
  28
  29 struct tegra_smmu {
  30         void __iomem *regs;
  31         struct device *dev;
  32
  33         struct tegra_mc *mc;
  34         const struct tegra_smmu_soc *soc;
  35
  36         struct list_head groups;
  37
  38         unsigned long pfn_mask;
  39         unsigned long tlb_mask;
  40
  41         unsigned long *asids;
  42         struct mutex lock;
  43
  44         struct list_head list;
  45
  46         struct dentry *debugfs;
  47
  48         struct iommu_device iommu;      /* IOMMU Core code handle */
  49 };
  50
  51 struct tegra_smmu_as {
  52         struct iommu_domain domain;
  53         struct tegra_smmu *smmu;
  54         unsigned int use_count;
  55         u32 *count;
  56         struct page **pts;
  57         struct page *pd;
  58         dma_addr_t pd_dma;
  59         unsigned id;
  60         u32 attr;
  61 };
  62
  63 static struct tegra_smmu_as *to_smmu_as(struct iommu_domain *dom)
  64 {
  65         return container_of(dom, struct tegra_smmu_as, domain);
  66 }
  67
  68 static inline void smmu_writel(struct tegra_smmu *smmu, u32 value,
  69                                unsigned long offset)
  70 {
  71         writel(value, smmu->regs + offset);
  72 }
  73
  74 static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
  75 {
  76         return readl(smmu->regs + offset);
  77 }
  78
  79 #define SMMU_CONFIG 0x010
  80 #define  SMMU_CONFIG_ENABLE (1 << 0)
  81
  82 #define SMMU_TLB_CONFIG 0x14
  83 #define  SMMU_TLB_CONFIG_HIT_UNDER_MISS (1 << 29)
  84 #define  SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION (1 << 28)
  85 #define  SMMU_TLB_CONFIG_ACTIVE_LINES(smmu) \
  86         ((smmu)->soc->num_tlb_lines & (smmu)->tlb_mask)
  87
  88 #define SMMU_PTC_CONFIG 0x18
  89 #define  SMMU_PTC_CONFIG_ENABLE (1 << 29)
  90 #define  SMMU_PTC_CONFIG_REQ_LIMIT(x) (((x) & 0x0f) << 24)
  91 #define  SMMU_PTC_CONFIG_INDEX_MAP(x) ((x) & 0x3f)
  92
  93 #define SMMU_PTB_ASID 0x01c
  94 #define  SMMU_PTB_ASID_VALUE(x) ((x) & 0x7f)
  95
  96 #define SMMU_PTB_DATA 0x020
  97 #define  SMMU_PTB_DATA_VALUE(dma, attr) ((dma) >> 12 | (attr))
  98
  99 #define SMMU_MK_PDE(dma, attr) ((dma) >> SMMU_PTE_SHIFT | (attr))
 100
 101 #define SMMU_TLB_FLUSH 0x030
 102 #define  SMMU_TLB_FLUSH_VA_MATCH_ALL     (0 << 0)
 103 #define  SMMU_TLB_FLUSH_VA_MATCH_SECTION (2 << 0)
 104 #define  SMMU_TLB_FLUSH_VA_MATCH_GROUP   (3 << 0)
 105 #define  SMMU_TLB_FLUSH_ASID(x)          (((x) & 0x7f) << 24)
 106 #define  SMMU_TLB_FLUSH_VA_SECTION(addr) ((((addr) & 0xffc00000) >> 12) | \
 107                                           SMMU_TLB_FLUSH_VA_MATCH_SECTION)
 108 #define  SMMU_TLB_FLUSH_VA_GROUP(addr)   ((((addr) & 0xffffc000) >> 12) | \
 109                                           SMMU_TLB_FLUSH_VA_MATCH_GROUP)
 110 #define  SMMU_TLB_FLUSH_ASID_MATCH       (1 << 31)
 111
 112 #define SMMU_PTC_FLUSH 0x034
 113 #define  SMMU_PTC_FLUSH_TYPE_ALL (0 << 0)
 114 #define  SMMU_PTC_FLUSH_TYPE_ADR (1 << 0)
 115
 116 #define SMMU_PTC_FLUSH_HI 0x9b8
 117 #define  SMMU_PTC_FLUSH_HI_MASK 0x3
 118
 119 /* per-SWGROUP SMMU_*_ASID register */
 120 #define SMMU_ASID_ENABLE (1 << 31)
 121 #define SMMU_ASID_MASK 0x7f
 122 #define SMMU_ASID_VALUE(x) ((x) & SMMU_ASID_MASK)
 123
 124 /* page table definitions */
 125 #define SMMU_NUM_PDE 1024
 126 #define SMMU_NUM_PTE 1024
 127
 128 #define SMMU_SIZE_PD (SMMU_NUM_PDE * 4)
 129 #define SMMU_SIZE_PT (SMMU_NUM_PTE * 4)
 130
 131 #define SMMU_PDE_SHIFT 22
 132 #define SMMU_PTE_SHIFT 12
 133
 134 #define SMMU_PD_READABLE        (1 << 31)
 135 #define SMMU_PD_WRITABLE        (1 << 30)
 136 #define SMMU_PD_NONSECURE       (1 << 29)
 137
 138 #define SMMU_PDE_READABLE       (1 << 31)
 139 #define SMMU_PDE_WRITABLE       (1 << 30)
 140 #define SMMU_PDE_NONSECURE      (1 << 29)
 141 #define SMMU_PDE_NEXT           (1 << 28)
 142
 143 #define SMMU_PTE_READABLE       (1 << 31)
 144 #define SMMU_PTE_WRITABLE       (1 << 30)
 145 #define SMMU_PTE_NONSECURE      (1 << 29)
 146
 147 #define SMMU_PDE_ATTR           (SMMU_PDE_READABLE | SMMU_PDE_WRITABLE | \
 148                                  SMMU_PDE_NONSECURE)
 149 #define SMMU_PTE_ATTR           (SMMU_PTE_READABLE | SMMU_PTE_WRITABLE | \
 150                                  SMMU_PTE_NONSECURE)
 151
 152 static unsigned int iova_pd_index(unsigned long iova)
 153 {
 154         return (iova >> SMMU_PDE_SHIFT) & (SMMU_NUM_PDE - 1);
 155 }
 156
 157 static unsigned int iova_pt_index(unsigned long iova)
 158 {
 159         return (iova >> SMMU_PTE_SHIFT) & (SMMU_NUM_PTE - 1);
 160 }
 161
 162 static bool smmu_dma_addr_valid(struct tegra_smmu *smmu, dma_addr_t addr)
 163 {
 164         addr >>= 12;
 165         return (addr & smmu->pfn_mask) == addr;
 166 }
 167
 168 static dma_addr_t smmu_pde_to_dma(u32 pde)
 169 {
 170         return pde << 12;
 171 }
 172
 173 static void smmu_flush_ptc_all(struct tegra_smmu *smmu)
 174 {
 175         smmu_writel(smmu, SMMU_PTC_FLUSH_TYPE_ALL, SMMU_PTC_FLUSH);
 176 }
 177
 178 static inline void smmu_flush_ptc(struct tegra_smmu *smmu, dma_addr_t dma,
 179                                   unsigned long offset)
 180 {
 181         u32 value;
 182
 183         offset &= ~(smmu->mc->soc->atom_size - 1);
 184
 185         if (smmu->mc->soc->num_address_bits > 32) {
 186 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 187                 value = (dma >> 32) & SMMU_PTC_FLUSH_HI_MASK;
 188 #else
 189                 value = 0;
 190 #endif
 191                 smmu_writel(smmu, value, SMMU_PTC_FLUSH_HI);
 192         }
 193
 194         value = (dma + offset) | SMMU_PTC_FLUSH_TYPE_ADR;
 195         smmu_writel(smmu, value, SMMU_PTC_FLUSH);
 196 }
 197
 198 static inline void smmu_flush_tlb(struct tegra_smmu *smmu)
 199 {
 200         smmu_writel(smmu, SMMU_TLB_FLUSH_VA_MATCH_ALL, SMMU_TLB_FLUSH);
 201 }
 202
 203 static inline void smmu_flush_tlb_asid(struct tegra_smmu *smmu,
 204                                        unsigned long asid)
 205 {
 206         u32 value;
 207
 208         value = SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_ASID(asid) |
 209                 SMMU_TLB_FLUSH_VA_MATCH_ALL;
 210         smmu_writel(smmu, value, SMMU_TLB_FLUSH);
 211 }
 212
 213 static inline void smmu_flush_tlb_section(struct tegra_smmu *smmu,
 214                                           unsigned long asid,
 215                                           unsigned long iova)
 216 {
 217         u32 value;
 218
 219         value = SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_ASID(asid) |
 220                 SMMU_TLB_FLUSH_VA_SECTION(iova);
 221         smmu_writel(smmu, value, SMMU_TLB_FLUSH);
 222 }
 223
 224 static inline void smmu_flush_tlb_group(struct tegra_smmu *smmu,
 225                                         unsigned long asid,
 226                                         unsigned long iova)
 227 {
 228         u32 value;
 229
 230         value = SMMU_TLB_FLUSH_ASID_MATCH | SMMU_TLB_FLUSH_ASID(asid) |
 231                 SMMU_TLB_FLUSH_VA_GROUP(iova);
 232         smmu_writel(smmu, value, SMMU_TLB_FLUSH);
 233 }
 234
 235 static inline void smmu_flush(struct tegra_smmu *smmu)
 236 {
 237         smmu_readl(smmu, SMMU_CONFIG);
 238 }
 239
 240 static int tegra_smmu_alloc_asid(struct tegra_smmu *smmu, unsigned int *idp)
 241 {
 242         unsigned long id;
 243
 244         mutex_lock(&smmu->lock);
 245
 246         id = find_first_zero_bit(smmu->asids, smmu->soc->num_asids);
 247         if (id >= smmu->soc->num_asids) {
 248                 mutex_unlock(&smmu->lock);
 249                 return -ENOSPC;
 250         }
 251
 252         set_bit(id, smmu->asids);
 253         *idp = id;
 254
 255         mutex_unlock(&smmu->lock);
 256         return 0;
 257 }
 258
 259 static void tegra_smmu_free_asid(struct tegra_smmu *smmu, unsigned int id)
 260 {
 261         mutex_lock(&smmu->lock);
 262         clear_bit(id, smmu->asids);
 263         mutex_unlock(&smmu->lock);
 264 }
 265
 266 static bool tegra_smmu_capable(enum iommu_cap cap)
 267 {
 268         return false;
 269 }
 270
 271 static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
 272 {
 273         struct tegra_smmu_as *as;
 274
 275         if (type != IOMMU_DOMAIN_UNMANAGED)
 276                 return NULL;
 277
 278         as = kzalloc(sizeof(*as), GFP_KERNEL);
 279         if (!as)
 280                 return NULL;
 281
 282         as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;
 283
 284         as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
 285         if (!as->pd) {
 286                 kfree(as);
 287                 return NULL;
 288         }
 289
 290         as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
 291         if (!as->count) {
 292                 __free_page(as->pd);
 293                 kfree(as);
 294                 return NULL;
 295         }
 296
 297         as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
 298         if (!as->pts) {
 299                 kfree(as->count);
 300                 __free_page(as->pd);
 301                 kfree(as);
 302                 return NULL;
 303         }
 304
 305         /* setup aperture */
 306         as->domain.geometry.aperture_start = 0;
 307         as->domain.geometry.aperture_end = 0xffffffff;
 308         as->domain.geometry.force_aperture = true;
 309
 310         return &as->domain;
 311 }
 312
 313 static void tegra_smmu_domain_free(struct iommu_domain *domain)
 314 {
 315         struct tegra_smmu_as *as = to_smmu_as(domain);
 316
 317         /* TODO: free page directory and page tables */
 318
 319         kfree(as);
 320 }
 321
 322 static const struct tegra_smmu_swgroup *
 323 tegra_smmu_find_swgroup(struct tegra_smmu *smmu, unsigned int swgroup)
 324 {
 325         const struct tegra_smmu_swgroup *group = NULL;
 326         unsigned int i;
 327
 328         for (i = 0; i < smmu->soc->num_swgroups; i++) {
 329                 if (smmu->soc->swgroups[i].swgroup == swgroup) {
 330                         group = &smmu->soc->swgroups[i];
 331                         break;
 332                 }
 333         }
 334
 335         return group;
 336 }
 337
 338 static void tegra_smmu_enable(struct tegra_smmu *smmu, unsigned int swgroup,
 339                               unsigned int asid)
 340 {
 341         const struct tegra_smmu_swgroup *group;
 342         unsigned int i;
 343         u32 value;
 344
 345         for (i = 0; i < smmu->soc->num_clients; i++) {
 346                 const struct tegra_mc_client *client = &smmu->soc->clients[i];
 347
 348                 if (client->swgroup != swgroup)
 349                         continue;
 350
 351                 value = smmu_readl(smmu, client->smmu.reg);
 352                 value |= BIT(client->smmu.bit);
 353                 smmu_writel(smmu, value, client->smmu.reg);
 354         }
 355
 356         group = tegra_smmu_find_swgroup(smmu, swgroup);
 357         if (group) {
 358                 value = smmu_readl(smmu, group->reg);
 359                 value &= ~SMMU_ASID_MASK;
 360                 value |= SMMU_ASID_VALUE(asid);
 361                 value |= SMMU_ASID_ENABLE;
 362                 smmu_writel(smmu, value, group->reg);
 363         }
 364 }
 365
 366 static void tegra_smmu_disable(struct tegra_smmu *smmu, unsigned int swgroup,
 367                                unsigned int asid)
 368 {
 369         const struct tegra_smmu_swgroup *group;
 370         unsigned int i;
 371         u32 value;
 372
 373         group = tegra_smmu_find_swgroup(smmu, swgroup);
 374         if (group) {
 375                 value = smmu_readl(smmu, group->reg);
 376                 value &= ~SMMU_ASID_MASK;
 377                 value |= SMMU_ASID_VALUE(asid);
 378                 value &= ~SMMU_ASID_ENABLE;
 379                 smmu_writel(smmu, value, group->reg);
 380         }
 381
 382         for (i = 0; i < smmu->soc->num_clients; i++) {
 383                 const struct tegra_mc_client *client = &smmu->soc->clients[i];
 384
 385                 if (client->swgroup != swgroup)
 386                         continue;
 387
 388                 value = smmu_readl(smmu, client->smmu.reg);
 389                 value &= ~BIT(client->smmu.bit);
 390                 smmu_writel(smmu, value, client->smmu.reg);
 391         }
 392 }
 393
 394 static int tegra_smmu_as_prepare(struct tegra_smmu *smmu,
 395                                  struct tegra_smmu_as *as)
 396 {
 397         u32 value;
 398         int err;
 399
 400         if (as->use_count > 0) {
 401                 as->use_count++;
 402                 return 0;
 403         }
 404
 405         as->pd_dma = dma_map_page(smmu->dev, as->pd, 0, SMMU_SIZE_PD,
 406                                   DMA_TO_DEVICE);
 407         if (dma_mapping_error(smmu->dev, as->pd_dma))
 408                 return -ENOMEM;
 409
 410         /* We can't handle 64-bit DMA addresses */
 411         if (!smmu_dma_addr_valid(smmu, as->pd_dma)) {
 412                 err = -ENOMEM;
 413                 goto err_unmap;
 414         }
 415
 416         err = tegra_smmu_alloc_asid(smmu, &as->id);
 417         if (err < 0)
 418                 goto err_unmap;
 419
 420         smmu_flush_ptc(smmu, as->pd_dma, 0);
 421         smmu_flush_tlb_asid(smmu, as->id);
 422
 423         smmu_writel(smmu, as->id & 0x7f, SMMU_PTB_ASID);
 424         value = SMMU_PTB_DATA_VALUE(as->pd_dma, as->attr);
 425         smmu_writel(smmu, value, SMMU_PTB_DATA);
 426         smmu_flush(smmu);
 427
 428         as->smmu = smmu;
 429         as->use_count++;
 430
 431         return 0;
 432
 433 err_unmap:
 434         dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
 435         return err;
 436 }
 437
 438 static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
 439                                     struct tegra_smmu_as *as)
 440 {
 441         if (--as->use_count > 0)
 442                 return;
 443
 444         tegra_smmu_free_asid(smmu, as->id);
 445
 446         dma_unmap_page(smmu->dev, as->pd_dma, SMMU_SIZE_PD, DMA_TO_DEVICE);
 447
 448         as->smmu = NULL;
 449 }
 450
 451 static int tegra_smmu_attach_dev(struct iommu_domain *domain,
 452                                  struct device *dev)
 453 {
 454         struct tegra_smmu *smmu = dev->archdata.iommu;
 455         struct tegra_smmu_as *as = to_smmu_as(domain);
 456         struct device_node *np = dev->of_node;
 457         struct of_phandle_args args;
 458         unsigned int index = 0;
 459         int err = 0;
 460
 461         while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
 462                                            &args)) {
 463                 unsigned int swgroup = args.args[0];
 464
 465                 if (args.np != smmu->dev->of_node) {
 466                         of_node_put(args.np);
 467                         continue;
 468                 }
 469
 470                 of_node_put(args.np);
 471
 472                 err = tegra_smmu_as_prepare(smmu, as);
 473                 if (err < 0)
 474                         return err;
 475
 476                 tegra_smmu_enable(smmu, swgroup, as->id);
 477                 index++;
 478         }
 479
 480         if (index == 0)
 481                 return -ENODEV;
 482
 483         return 0;
 484 }
 485
 486 static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
 487 {
 488         struct tegra_smmu_as *as = to_smmu_as(domain);
 489         struct device_node *np = dev->of_node;
 490         struct tegra_smmu *smmu = as->smmu;
 491         struct of_phandle_args args;
 492         unsigned int index = 0;
 493
 494         while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
 495                                            &args)) {
 496                 unsigned int swgroup = args.args[0];
 497
 498                 if (args.np != smmu->dev->of_node) {
 499                         of_node_put(args.np);
 500                         continue;
 501                 }
 502
 503                 of_node_put(args.np);
 504
 505                 tegra_smmu_disable(smmu, swgroup, as->id);
 506                 tegra_smmu_as_unprepare(smmu, as);
 507                 index++;
 508         }
 509 }
 510
 511 static void tegra_smmu_set_pde(struct tegra_smmu_as *as, unsigned long iova,
 512                                u32 value)
 513 {
 514         unsigned int pd_index = iova_pd_index(iova);
 515         struct tegra_smmu *smmu = as->smmu;
 516         u32 *pd = page_address(as->pd);
 517         unsigned long offset = pd_index * sizeof(*pd);
 518
 519         /* Set the page directory entry first */
 520         pd[pd_index] = value;
 521
 522         /* The flush the page directory entry from caches */
 523         dma_sync_single_range_for_device(smmu->dev, as->pd_dma, offset,
 524                                          sizeof(*pd), DMA_TO_DEVICE);
 525
 526         /* And flush the iommu */
 527         smmu_flush_ptc(smmu, as->pd_dma, offset);
 528         smmu_flush_tlb_section(smmu, as->id, iova);
 529         smmu_flush(smmu);
 530 }
 531
 532 static u32 *tegra_smmu_pte_offset(struct page *pt_page, unsigned long iova)
 533 {
 534         u32 *pt = page_address(pt_page);
 535
 536         return pt + iova_pt_index(iova);
 537 }
 538
 539 static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
 540                                   dma_addr_t *dmap)
 541 {
 542         unsigned int pd_index = iova_pd_index(iova);
 543         struct page *pt_page;
 544         u32 *pd;
 545
 546         pt_page = as->pts[pd_index];
 547         if (!pt_page)
 548                 return NULL;
 549
 550         pd = page_address(as->pd);
 551         *dmap = smmu_pde_to_dma(pd[pd_index]);
 552
 553         return tegra_smmu_pte_offset(pt_page, iova);
 554 }
 555
 556 static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
 557                        dma_addr_t *dmap)
 558 {
 559         unsigned int pde = iova_pd_index(iova);
 560         struct tegra_smmu *smmu = as->smmu;
 561
 562         if (!as->pts[pde]) {
 563                 struct page *page;
 564                 dma_addr_t dma;
 565
 566                 page = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
 567                 if (!page)
 568                         return NULL;
 569
 570                 dma = dma_map_page(smmu->dev, page, 0, SMMU_SIZE_PT,
 571                                    DMA_TO_DEVICE);
 572                 if (dma_mapping_error(smmu->dev, dma)) {
 573                         __free_page(page);
 574                         return NULL;
 575                 }
 576
 577                 if (!smmu_dma_addr_valid(smmu, dma)) {
 578                         dma_unmap_page(smmu->dev, dma, SMMU_SIZE_PT,
 579                                        DMA_TO_DEVICE);
 580                         __free_page(page);
 581                         return NULL;
 582                 }
 583
 584                 as->pts[pde] = page;
 585
 586                 tegra_smmu_set_pde(as, iova, SMMU_MK_PDE(dma, SMMU_PDE_ATTR |
 587                                                               SMMU_PDE_NEXT));
 588
 589                 *dmap = dma;
 590         } else {
 591                 u32 *pd = page_address(as->pd);
 592
 593                 *dmap = smmu_pde_to_dma(pd[pde]);
 594         }
 595
 596         return tegra_smmu_pte_offset(as->pts[pde], iova);
 597 }
 598
 599 static void tegra_smmu_pte_get_use(struct tegra_smmu_as *as, unsigned long iova)
 600 {
 601         unsigned int pd_index = iova_pd_index(iova);
 602
 603         as->count[pd_index]++;
 604 }
 605
 606 static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
 607 {
 608         unsigned int pde = iova_pd_index(iova);
 609         struct page *page = as->pts[pde];
 610
 611         /*
 612          * When no entries in this page table are used anymore, return the
 613          * memory page to the system.
 614          */
 615         if (--as->count[pde] == 0) {
 616                 struct tegra_smmu *smmu = as->smmu;
 617                 u32 *pd = page_address(as->pd);
 618                 dma_addr_t pte_dma = smmu_pde_to_dma(pd[pde]);
 619
 620                 tegra_smmu_set_pde(as, iova, 0);
 621
 622                 dma_unmap_page(smmu->dev, pte_dma, SMMU_SIZE_PT, DMA_TO_DEVICE);
 623                 __free_page(page);
 624                 as->pts[pde] = NULL;
 625         }
 626 }
 627
 628 static void tegra_smmu_set_pte(struct tegra_smmu_as *as, unsigned long iova,
 629                                u32 *pte, dma_addr_t pte_dma, u32 val)
 630 {
 631         struct tegra_smmu *smmu = as->smmu;
 632         unsigned long offset = offset_in_page(pte);
 633
 634         *pte = val;
 635
 636         dma_sync_single_range_for_device(smmu->dev, pte_dma, offset,
 637                                          4, DMA_TO_DEVICE);
 638         smmu_flush_ptc(smmu, pte_dma, offset);
 639         smmu_flush_tlb_group(smmu, as->id, iova);
 640         smmu_flush(smmu);
 641 }
 642
 643 static int tegra_smmu_map(struct iommu_domain *domain, unsigned long iova,
 644                           phys_addr_t paddr, size_t size, int prot)
 645 {
 646         struct tegra_smmu_as *as = to_smmu_as(domain);
 647         dma_addr_t pte_dma;
 648         u32 *pte;
 649
 650         pte = as_get_pte(as, iova, &pte_dma);
 651         if (!pte)
 652                 return -ENOMEM;
 653
 654         /* If we aren't overwriting a pre-existing entry, increment use */
 655         if (*pte == 0)
 656                 tegra_smmu_pte_get_use(as, iova);
 657
 658         tegra_smmu_set_pte(as, iova, pte, pte_dma,
 659                            __phys_to_pfn(paddr) | SMMU_PTE_ATTR);
 660
 661         return 0;
 662 }
 663
 664 static size_t tegra_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
 665                                size_t size)
 666 {
 667         struct tegra_smmu_as *as = to_smmu_as(domain);
 668         dma_addr_t pte_dma;
 669         u32 *pte;
 670
 671         pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
 672         if (!pte || !*pte)
 673                 return 0;
 674
 675         tegra_smmu_set_pte(as, iova, pte, pte_dma, 0);
 676         tegra_smmu_pte_put_use(as, iova);
 677
 678         return size;
 679 }
 680
 681 static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
 682                                            dma_addr_t iova)
 683 {
 684         struct tegra_smmu_as *as = to_smmu_as(domain);
 685         unsigned long pfn;
 686         dma_addr_t pte_dma;
 687         u32 *pte;
 688
 689         pte = tegra_smmu_pte_lookup(as, iova, &pte_dma);
 690         if (!pte || !*pte)
 691                 return 0;
 692
 693         pfn = *pte & as->smmu->pfn_mask;
 694
 695         return PFN_PHYS(pfn);
 696 }
 697
 698 static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
 699 {
 700         struct platform_device *pdev;
 701         struct tegra_mc *mc;
 702
 703         pdev = of_find_device_by_node(np);
 704         if (!pdev)
 705                 return NULL;
 706
 707         mc = platform_get_drvdata(pdev);
 708         if (!mc)
 709                 return NULL;
 710
 711         return mc->smmu;
 712 }
 713
 714 static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
 715                                 struct of_phandle_args *args)
 716 {
 717         const struct iommu_ops *ops = smmu->iommu.ops;
 718         int err;
 719
 720         err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
 721         if (err < 0) {
 722                 dev_err(dev, "failed to initialize fwspec: %d\n", err);
 723                 return err;
 724         }
 725
 726         err = ops->of_xlate(dev, args);
 727         if (err < 0) {
 728                 dev_err(dev, "failed to parse SW group ID: %d\n", err);
 729                 iommu_fwspec_free(dev);
 730                 return err;
 731         }
 732
 733         return 0;
 734 }
 735
 736 static int tegra_smmu_add_device(struct device *dev)
 737 {
 738         struct device_node *np = dev->of_node;
 739         struct tegra_smmu *smmu = NULL;
 740         struct iommu_group *group;
 741         struct of_phandle_args args;
 742         unsigned int index = 0;
 743         int err;
 744
 745         while (of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
 746                                           &args) == 0) {
 747                 smmu = tegra_smmu_find(args.np);
 748                 if (smmu) {
 749                         err = tegra_smmu_configure(smmu, dev, &args);
 750                         of_node_put(args.np);
 751
 752                         if (err < 0)
 753                                 return err;
 754
 755                         /*
 756                          * Only a single IOMMU master interface is currently
 757                          * supported by the Linux kernel, so abort after the
 758                          * first match.
 759                          */
 760                         dev->archdata.iommu = smmu;
 761
 762                         iommu_device_link(&smmu->iommu, dev);
 763
 764                         break;
 765                 }
 766
 767                 of_node_put(args.np);
 768                 index++;
 769         }
 770
 771         if (!smmu)
 772                 return -ENODEV;
 773
 774         group = iommu_group_get_for_dev(dev);
 775         if (IS_ERR(group))
 776                 return PTR_ERR(group);
 777
 778         iommu_group_put(group);
 779
 780         return 0;
 781 }
 782
 783 static void tegra_smmu_remove_device(struct device *dev)
 784 {
 785         struct tegra_smmu *smmu = dev->archdata.iommu;
 786
 787         if (smmu)
 788                 iommu_device_unlink(&smmu->iommu, dev);
 789
 790         dev->archdata.iommu = NULL;
 791         iommu_group_remove_device(dev);
 792 }
 793
 794 static const struct tegra_smmu_group_soc *
 795 tegra_smmu_find_group(struct tegra_smmu *smmu, unsigned int swgroup)
 796 {
 797         unsigned int i, j;
 798
 799         for (i = 0; i < smmu->soc->num_groups; i++)
 800                 for (j = 0; j < smmu->soc->groups[i].num_swgroups; j++)
 801                         if (smmu->soc->groups[i].swgroups[j] == swgroup)
 802                                 return &smmu->soc->groups[i];
 803
 804         return NULL;
 805 }
 806
 807 static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
 808                                                 unsigned int swgroup)
 809 {
 810         const struct tegra_smmu_group_soc *soc;
 811         struct tegra_smmu_group *group;
 812
 813         soc = tegra_smmu_find_group(smmu, swgroup);
 814         if (!soc)
 815                 return NULL;
 816
 817         mutex_lock(&smmu->lock);
 818
 819         list_for_each_entry(group, &smmu->groups, list)
 820                 if (group->soc == soc) {
 821                         mutex_unlock(&smmu->lock);
 822                         return group->group;
 823                 }
 824
 825         group = devm_kzalloc(smmu->dev, sizeof(*group), GFP_KERNEL);
 826         if (!group) {
 827                 mutex_unlock(&smmu->lock);
 828                 return NULL;
 829         }
 830
 831         INIT_LIST_HEAD(&group->list);
 832         group->soc = soc;
 833
 834         group->group = iommu_group_alloc();
 835         if (IS_ERR(group->group)) {
 836                 devm_kfree(smmu->dev, group);
 837                 mutex_unlock(&smmu->lock);
 838                 return NULL;
 839         }
 840
 841         list_add_tail(&group->list, &smmu->groups);
 842         mutex_unlock(&smmu->lock);
 843
 844         return group->group;
 845 }
 846
 847 static struct iommu_group *tegra_smmu_device_group(struct device *dev)
 848 {
 849         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 850         struct tegra_smmu *smmu = dev->archdata.iommu;
 851         struct iommu_group *group;
 852
 853         group = tegra_smmu_group_get(smmu, fwspec->ids[0]);
 854         if (!group)
 855                 group = generic_device_group(dev);
 856
 857         return group;
 858 }
 859
 860 static int tegra_smmu_of_xlate(struct device *dev,
 861                                struct of_phandle_args *args)
 862 {
 863         u32 id = args->args[0];
 864
 865         return iommu_fwspec_add_ids(dev, &id, 1);
 866 }
 867
 868 static const struct iommu_ops tegra_smmu_ops = {
 869         .capable = tegra_smmu_capable,
 870         .domain_alloc = tegra_smmu_domain_alloc,
 871         .domain_free = tegra_smmu_domain_free,
 872         .attach_dev = tegra_smmu_attach_dev,
 873         .detach_dev = tegra_smmu_detach_dev,
 874         .add_device = tegra_smmu_add_device,
 875         .remove_device = tegra_smmu_remove_device,
 876         .device_group = tegra_smmu_device_group,
 877         .map = tegra_smmu_map,
 878         .unmap = tegra_smmu_unmap,
 879         .iova_to_phys = tegra_smmu_iova_to_phys,
 880         .of_xlate = tegra_smmu_of_xlate,
 881         .pgsize_bitmap = SZ_4K,
 882 };
 883
 884 static void tegra_smmu_ahb_enable(void)
 885 {
 886         static const struct of_device_id ahb_match[] = {
 887                 { .compatible = "nvidia,tegra30-ahb", },
 888                 { }
 889         };
 890         struct device_node *ahb;
 891
 892         ahb = of_find_matching_node(NULL, ahb_match);
 893         if (ahb) {
 894                 tegra_ahb_enable_smmu(ahb);
 895                 of_node_put(ahb);
 896         }
 897 }
 898
 899 static int tegra_smmu_swgroups_show(struct seq_file *s, void *data)
 900 {
 901         struct tegra_smmu *smmu = s->private;
 902         unsigned int i;
 903         u32 value;
 904
 905         seq_printf(s, "swgroup    enabled  ASID\n");
 906         seq_printf(s, "------------------------\n");
 907
 908         for (i = 0; i < smmu->soc->num_swgroups; i++) {
 909                 const struct tegra_smmu_swgroup *group = &smmu->soc->swgroups[i];
 910                 const char *status;
 911                 unsigned int asid;
 912
 913                 value = smmu_readl(smmu, group->reg);
 914
 915                 if (value & SMMU_ASID_ENABLE)
 916                         status = "yes";
 917                 else
 918                         status = "no";
 919
 920                 asid = value & SMMU_ASID_MASK;
 921
 922                 seq_printf(s, "%-9s  %-7s  %#04x\n", group->name, status,
 923                            asid);
 924         }
 925
 926         return 0;
 927 }
 928
 929 DEFINE_SHOW_ATTRIBUTE(tegra_smmu_swgroups);
 930
 931 static int tegra_smmu_clients_show(struct seq_file *s, void *data)
 932 {
 933         struct tegra_smmu *smmu = s->private;
 934         unsigned int i;
 935         u32 value;
 936
 937         seq_printf(s, "client       enabled\n");
 938         seq_printf(s, "--------------------\n");
 939
 940         for (i = 0; i < smmu->soc->num_clients; i++) {
 941                 const struct tegra_mc_client *client = &smmu->soc->clients[i];
 942                 const char *status;
 943
 944                 value = smmu_readl(smmu, client->smmu.reg);
 945
 946                 if (value & BIT(client->smmu.bit))
 947                         status = "yes";
 948                 else
 949                         status = "no";
 950
 951                 seq_printf(s, "%-12s %s\n", client->name, status);
 952         }
 953
 954         return 0;
 955 }
 956
 957 DEFINE_SHOW_ATTRIBUTE(tegra_smmu_clients);
 958
 959 static void tegra_smmu_debugfs_init(struct tegra_smmu *smmu)
 960 {
 961         smmu->debugfs = debugfs_create_dir("smmu", NULL);
 962         if (!smmu->debugfs)
 963                 return;
 964
 965         debugfs_create_file("swgroups", S_IRUGO, smmu->debugfs, smmu,
 966                             &tegra_smmu_swgroups_fops);
 967         debugfs_create_file("clients", S_IRUGO, smmu->debugfs, smmu,
 968                             &tegra_smmu_clients_fops);
 969 }
 970
 971 static void tegra_smmu_debugfs_exit(struct tegra_smmu *smmu)
 972 {
 973         debugfs_remove_recursive(smmu->debugfs);
 974 }
 975
 976 struct tegra_smmu *tegra_smmu_probe(struct device *dev,
 977                                     const struct tegra_smmu_soc *soc,
 978                                     struct tegra_mc *mc)
 979 {
 980         struct tegra_smmu *smmu;
 981         size_t size;
 982         u32 value;
 983         int err;
 984
 985         smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
 986         if (!smmu)
 987                 return ERR_PTR(-ENOMEM);
 988
 989         /*
 990          * This is a bit of a hack. Ideally we'd want to simply return this
 991          * value. However the IOMMU registration process will attempt to add
 992          * all devices to the IOMMU when bus_set_iommu() is called. In order
 993          * not to rely on global variables to track the IOMMU instance, we
 994          * set it here so that it can be looked up from the .add_device()
 995          * callback via the IOMMU device's .drvdata field.
 996          */
 997         mc->smmu = smmu;
 998
 999         size = BITS_TO_LONGS(soc->num_asids) * sizeof(long);
1000
1001         smmu->asids = devm_kzalloc(dev, size, GFP_KERNEL);
1002         if (!smmu->asids)
1003                 return ERR_PTR(-ENOMEM);
1004
1005         INIT_LIST_HEAD(&smmu->groups);
1006         mutex_init(&smmu->lock);
1007
1008         smmu->regs = mc->regs;
1009         smmu->soc = soc;
1010         smmu->dev = dev;
1011         smmu->mc = mc;
1012
1013         smmu->pfn_mask = BIT_MASK(mc->soc->num_address_bits - PAGE_SHIFT) - 1;
1014         dev_dbg(dev, "address bits: %u, PFN mask: %#lx\n",
1015                 mc->soc->num_address_bits, smmu->pfn_mask);
1016         smmu->tlb_mask = (smmu->soc->num_tlb_lines << 1) - 1;
1017         dev_dbg(dev, "TLB lines: %u, mask: %#lx\n", smmu->soc->num_tlb_lines,
1018                 smmu->tlb_mask);
1019
1020         value = SMMU_PTC_CONFIG_ENABLE | SMMU_PTC_CONFIG_INDEX_MAP(0x3f);
1021
1022         if (soc->supports_request_limit)
1023                 value |= SMMU_PTC_CONFIG_REQ_LIMIT(8);
1024
1025         smmu_writel(smmu, value, SMMU_PTC_CONFIG);
1026
1027         value = SMMU_TLB_CONFIG_HIT_UNDER_MISS |
1028                 SMMU_TLB_CONFIG_ACTIVE_LINES(smmu);
1029
1030         if (soc->supports_round_robin_arbitration)
1031                 value |= SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION;
1032
1033         smmu_writel(smmu, value, SMMU_TLB_CONFIG);
1034
1035         smmu_flush_ptc_all(smmu);
1036         smmu_flush_tlb(smmu);
1037         smmu_writel(smmu, SMMU_CONFIG_ENABLE, SMMU_CONFIG);
1038         smmu_flush(smmu);
1039
1040         tegra_smmu_ahb_enable();
1041
1042         err = iommu_device_sysfs_add(&smmu->iommu, dev, NULL, dev_name(dev));
1043         if (err)
1044                 return ERR_PTR(err);
1045
1046         iommu_device_set_ops(&smmu->iommu, &tegra_smmu_ops);
1047         iommu_device_set_fwnode(&smmu->iommu, dev->fwnode);
1048
1049         err = iommu_device_register(&smmu->iommu);
1050         if (err) {
1051                 iommu_device_sysfs_remove(&smmu->iommu);
1052                 return ERR_PTR(err);
1053         }
1054
1055         err = bus_set_iommu(&platform_bus_type, &tegra_smmu_ops);
1056         if (err < 0) {
1057                 iommu_device_unregister(&smmu->iommu);
1058                 iommu_device_sysfs_remove(&smmu->iommu);
1059                 return ERR_PTR(err);
1060         }
1061
1062         if (IS_ENABLED(CONFIG_DEBUG_FS))
1063                 tegra_smmu_debugfs_init(smmu);
1064
1065         return smmu;
1066 }
1067
1068 void tegra_smmu_remove(struct tegra_smmu *smmu)
1069 {
1070         iommu_device_unregister(&smmu->iommu);
1071         iommu_device_sysfs_remove(&smmu->iommu);
1072
1073         if (IS_ENABLED(CONFIG_DEBUG_FS))
1074                 tegra_smmu_debugfs_exit(smmu);
1075 }