drivers/iommu/ipmmu-vmsa.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * IOMMU API for Renesas VMSA-compatible IPMMU
   4  * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   5  *
   6  * Copyright (C) 2014-2020 Renesas Electronics Corporation
   7  */
   8
   9 #include <linux/bitmap.h>
  10 #include <linux/delay.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/err.h>
  13 #include <linux/export.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/io-pgtable.h>
  18 #include <linux/iommu.h>
  19 #include <linux/of.h>
  20 #include <linux/of_device.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/sizes.h>
  24 #include <linux/slab.h>
  25 #include <linux/sys_soc.h>
  26
  27 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
  28 #include <asm/dma-iommu.h>
  29 #else
  30 #define arm_iommu_create_mapping(...)   NULL
  31 #define arm_iommu_attach_device(...)    -ENODEV
  32 #define arm_iommu_release_mapping(...)  do {} while (0)
  33 #define arm_iommu_detach_device(...)    do {} while (0)
  34 #endif
  35
  36 #define IPMMU_CTX_MAX           16U
  37 #define IPMMU_CTX_INVALID       -1
  38
  39 #define IPMMU_UTLB_MAX          64U
  40
  41 struct ipmmu_features {
  42         bool use_ns_alias_offset;
  43         bool has_cache_leaf_nodes;
  44         unsigned int number_of_contexts;
  45         unsigned int num_utlbs;
  46         bool setup_imbuscr;
  47         bool twobit_imttbcr_sl0;
  48         bool reserved_context;
  49         bool cache_snoop;
  50         unsigned int ctx_offset_base;
  51         unsigned int ctx_offset_stride;
  52         unsigned int utlb_offset_base;
  53 };
  54
  55 struct ipmmu_vmsa_device {
  56         struct device *dev;
  57         void __iomem *base;
  58         struct iommu_device iommu;
  59         struct ipmmu_vmsa_device *root;
  60         const struct ipmmu_features *features;
  61         unsigned int num_ctx;
  62         spinlock_t lock;                        /* Protects ctx and domains[] */
  63         DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
  64         struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
  65         s8 utlb_ctx[IPMMU_UTLB_MAX];
  66
  67         struct iommu_group *group;
  68         struct dma_iommu_mapping *mapping;
  69 };
  70
  71 struct ipmmu_vmsa_domain {
  72         struct ipmmu_vmsa_device *mmu;
  73         struct iommu_domain io_domain;
  74
  75         struct io_pgtable_cfg cfg;
  76         struct io_pgtable_ops *iop;
  77
  78         unsigned int context_id;
  79         struct mutex mutex;                     /* Protects mappings */
  80 };
  81
  82 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
  83 {
  84         return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
  85 }
  86
  87 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
  88 {
  89         return dev_iommu_priv_get(dev);
  90 }
  91
  92 #define TLB_LOOP_TIMEOUT                100     /* 100us */
  93
  94 /* -----------------------------------------------------------------------------
  95  * Registers Definition
  96  */
  97
  98 #define IM_NS_ALIAS_OFFSET              0x800
  99
 100 /* MMU "context" registers */
 101 #define IMCTR                           0x0000          /* R-Car Gen2/3 */
 102 #define IMCTR_INTEN                     (1 << 2)        /* R-Car Gen2/3 */
 103 #define IMCTR_FLUSH                     (1 << 1)        /* R-Car Gen2/3 */
 104 #define IMCTR_MMUEN                     (1 << 0)        /* R-Car Gen2/3 */
 105
 106 #define IMTTBCR                         0x0008          /* R-Car Gen2/3 */
 107 #define IMTTBCR_EAE                     (1 << 31)       /* R-Car Gen2/3 */
 108 #define IMTTBCR_SH0_INNER_SHAREABLE     (3 << 12)       /* R-Car Gen2 only */
 109 #define IMTTBCR_ORGN0_WB_WA             (1 << 10)       /* R-Car Gen2 only */
 110 #define IMTTBCR_IRGN0_WB_WA             (1 << 8)        /* R-Car Gen2 only */
 111 #define IMTTBCR_SL0_TWOBIT_LVL_1        (2 << 6)        /* R-Car Gen3 only */
 112 #define IMTTBCR_SL0_LVL_1               (1 << 4)        /* R-Car Gen2 only */
 113
 114 #define IMBUSCR                         0x000c          /* R-Car Gen2 only */
 115 #define IMBUSCR_DVM                     (1 << 2)        /* R-Car Gen2 only */
 116 #define IMBUSCR_BUSSEL_MASK             (3 << 0)        /* R-Car Gen2 only */
 117
 118 #define IMTTLBR0                        0x0010          /* R-Car Gen2/3 */
 119 #define IMTTUBR0                        0x0014          /* R-Car Gen2/3 */
 120
 121 #define IMSTR                           0x0020          /* R-Car Gen2/3 */
 122 #define IMSTR_MHIT                      (1 << 4)        /* R-Car Gen2/3 */
 123 #define IMSTR_ABORT                     (1 << 2)        /* R-Car Gen2/3 */
 124 #define IMSTR_PF                        (1 << 1)        /* R-Car Gen2/3 */
 125 #define IMSTR_TF                        (1 << 0)        /* R-Car Gen2/3 */
 126
 127 #define IMMAIR0                         0x0028          /* R-Car Gen2/3 */
 128
 129 #define IMELAR                          0x0030          /* R-Car Gen2/3, IMEAR on R-Car Gen2 */
 130 #define IMEUAR                          0x0034          /* R-Car Gen3 only */
 131
 132 /* uTLB registers */
 133 #define IMUCTR(n)                       ((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
 134 #define IMUCTR0(n)                      (0x0300 + ((n) * 16))           /* R-Car Gen2/3 */
 135 #define IMUCTR32(n)                     (0x0600 + (((n) - 32) * 16))    /* R-Car Gen3 only */
 136 #define IMUCTR_TTSEL_MMU(n)             ((n) << 4)      /* R-Car Gen2/3 */
 137 #define IMUCTR_FLUSH                    (1 << 1)        /* R-Car Gen2/3 */
 138 #define IMUCTR_MMUEN                    (1 << 0)        /* R-Car Gen2/3 */
 139
 140 #define IMUASID(n)                      ((n) < 32 ? IMUASID0(n) : IMUASID32(n))
 141 #define IMUASID0(n)                     (0x0308 + ((n) * 16))           /* R-Car Gen2/3 */
 142 #define IMUASID32(n)                    (0x0608 + (((n) - 32) * 16))    /* R-Car Gen3 only */
 143
 144 /* -----------------------------------------------------------------------------
 145  * Root device handling
 146  */
 147
 148 static struct platform_driver ipmmu_driver;
 149
 150 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
 151 {
 152         return mmu->root == mmu;
 153 }
 154
 155 static int __ipmmu_check_device(struct device *dev, void *data)
 156 {
 157         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
 158         struct ipmmu_vmsa_device **rootp = data;
 159
 160         if (ipmmu_is_root(mmu))
 161                 *rootp = mmu;
 162
 163         return 0;
 164 }
 165
 166 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
 167 {
 168         struct ipmmu_vmsa_device *root = NULL;
 169
 170         return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
 171                                       __ipmmu_check_device) == 0 ? root : NULL;
 172 }
 173
 174 /* -----------------------------------------------------------------------------
 175  * Read/Write Access
 176  */
 177
 178 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
 179 {
 180         return ioread32(mmu->base + offset);
 181 }
 182
 183 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 184                         u32 data)
 185 {
 186         iowrite32(data, mmu->base + offset);
 187 }
 188
 189 static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
 190                                   unsigned int context_id, unsigned int reg)
 191 {
 192         unsigned int base = mmu->features->ctx_offset_base;
 193
 194         if (context_id > 7)
 195                 base += 0x800 - 8 * 0x40;
 196
 197         return base + context_id * mmu->features->ctx_offset_stride + reg;
 198 }
 199
 200 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
 201                           unsigned int context_id, unsigned int reg)
 202 {
 203         return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
 204 }
 205
 206 static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
 207                             unsigned int context_id, unsigned int reg, u32 data)
 208 {
 209         ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
 210 }
 211
 212 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 213                                unsigned int reg)
 214 {
 215         return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
 216 }
 217
 218 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 219                                  unsigned int reg, u32 data)
 220 {
 221         ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 222 }
 223
 224 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 225                                 unsigned int reg, u32 data)
 226 {
 227         if (domain->mmu != domain->mmu->root)
 228                 ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
 229
 230         ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 231 }
 232
 233 static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
 234 {
 235         return mmu->features->utlb_offset_base + reg;
 236 }
 237
 238 static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
 239                                 unsigned int utlb, u32 data)
 240 {
 241         ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
 242 }
 243
 244 static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
 245                                unsigned int utlb, u32 data)
 246 {
 247         ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
 248 }
 249
 250 /* -----------------------------------------------------------------------------
 251  * TLB and microTLB Management
 252  */
 253
 254 /* Wait for any pending TLB invalidations to complete */
 255 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
 256 {
 257         unsigned int count = 0;
 258
 259         while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
 260                 cpu_relax();
 261                 if (++count == TLB_LOOP_TIMEOUT) {
 262                         dev_err_ratelimited(domain->mmu->dev,
 263                         "TLB sync timed out -- MMU may be deadlocked\n");
 264                         return;
 265                 }
 266                 udelay(1);
 267         }
 268 }
 269
 270 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
 271 {
 272         u32 reg;
 273
 274         reg = ipmmu_ctx_read_root(domain, IMCTR);
 275         reg |= IMCTR_FLUSH;
 276         ipmmu_ctx_write_all(domain, IMCTR, reg);
 277
 278         ipmmu_tlb_sync(domain);
 279 }
 280
 281 /*
 282  * Enable MMU translation for the microTLB.
 283  */
 284 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 285                               unsigned int utlb)
 286 {
 287         struct ipmmu_vmsa_device *mmu = domain->mmu;
 288
 289         /*
 290          * TODO: Reference-count the microTLB as several bus masters can be
 291          * connected to the same microTLB.
 292          */
 293
 294         /* TODO: What should we set the ASID to ? */
 295         ipmmu_imuasid_write(mmu, utlb, 0);
 296         /* TODO: Do we need to flush the microTLB ? */
 297         ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
 298                                       IMUCTR_FLUSH | IMUCTR_MMUEN);
 299         mmu->utlb_ctx[utlb] = domain->context_id;
 300 }
 301
 302 /*
 303  * Disable MMU translation for the microTLB.
 304  */
 305 static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 306                                unsigned int utlb)
 307 {
 308         struct ipmmu_vmsa_device *mmu = domain->mmu;
 309
 310         ipmmu_imuctr_write(mmu, utlb, 0);
 311         mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
 312 }
 313
 314 static void ipmmu_tlb_flush_all(void *cookie)
 315 {
 316         struct ipmmu_vmsa_domain *domain = cookie;
 317
 318         ipmmu_tlb_invalidate(domain);
 319 }
 320
 321 static void ipmmu_tlb_flush(unsigned long iova, size_t size,
 322                                 size_t granule, void *cookie)
 323 {
 324         ipmmu_tlb_flush_all(cookie);
 325 }
 326
 327 static const struct iommu_flush_ops ipmmu_flush_ops = {
 328         .tlb_flush_all = ipmmu_tlb_flush_all,
 329         .tlb_flush_walk = ipmmu_tlb_flush,
 330 };
 331
 332 /* -----------------------------------------------------------------------------
 333  * Domain/Context Management
 334  */
 335
 336 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
 337                                          struct ipmmu_vmsa_domain *domain)
 338 {
 339         unsigned long flags;
 340         int ret;
 341
 342         spin_lock_irqsave(&mmu->lock, flags);
 343
 344         ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
 345         if (ret != mmu->num_ctx) {
 346                 mmu->domains[ret] = domain;
 347                 set_bit(ret, mmu->ctx);
 348         } else
 349                 ret = -EBUSY;
 350
 351         spin_unlock_irqrestore(&mmu->lock, flags);
 352
 353         return ret;
 354 }
 355
 356 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 357                                       unsigned int context_id)
 358 {
 359         unsigned long flags;
 360
 361         spin_lock_irqsave(&mmu->lock, flags);
 362
 363         clear_bit(context_id, mmu->ctx);
 364         mmu->domains[context_id] = NULL;
 365
 366         spin_unlock_irqrestore(&mmu->lock, flags);
 367 }
 368
 369 static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
 370 {
 371         u64 ttbr;
 372         u32 tmp;
 373
 374         /* TTBR0 */
 375         ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
 376         ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
 377         ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 378
 379         /*
 380          * TTBCR
 381          * We use long descriptors and allocate the whole 32-bit VA space to
 382          * TTBR0.
 383          */
 384         if (domain->mmu->features->twobit_imttbcr_sl0)
 385                 tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
 386         else
 387                 tmp = IMTTBCR_SL0_LVL_1;
 388
 389         if (domain->mmu->features->cache_snoop)
 390                 tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
 391                        IMTTBCR_IRGN0_WB_WA;
 392
 393         ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
 394
 395         /* MAIR0 */
 396         ipmmu_ctx_write_root(domain, IMMAIR0,
 397                              domain->cfg.arm_lpae_s1_cfg.mair);
 398
 399         /* IMBUSCR */
 400         if (domain->mmu->features->setup_imbuscr)
 401                 ipmmu_ctx_write_root(domain, IMBUSCR,
 402                                      ipmmu_ctx_read_root(domain, IMBUSCR) &
 403                                      ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 404
 405         /*
 406          * IMSTR
 407          * Clear all interrupt flags.
 408          */
 409         ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
 410
 411         /*
 412          * IMCTR
 413          * Enable the MMU and interrupt generation. The long-descriptor
 414          * translation table format doesn't use TEX remapping. Don't enable AF
 415          * software management as we have no use for it. Flush the TLB as
 416          * required when modifying the context registers.
 417          */
 418         ipmmu_ctx_write_all(domain, IMCTR,
 419                             IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 420 }
 421
 422 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 423 {
 424         int ret;
 425
 426         /*
 427          * Allocate the page table operations.
 428          *
 429          * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
 430          * access, Long-descriptor format" that the NStable bit being set in a
 431          * table descriptor will result in the NStable and NS bits of all child
 432          * entries being ignored and considered as being set. The IPMMU seems
 433          * not to comply with this, as it generates a secure access page fault
 434          * if any of the NStable and NS bits isn't set when running in
 435          * non-secure mode.
 436          */
 437         domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
 438         domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
 439         domain->cfg.ias = 32;
 440         domain->cfg.oas = 40;
 441         domain->cfg.tlb = &ipmmu_flush_ops;
 442         domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
 443         domain->io_domain.geometry.force_aperture = true;
 444         /*
 445          * TODO: Add support for coherent walk through CCI with DVM and remove
 446          * cache handling. For now, delegate it to the io-pgtable code.
 447          */
 448         domain->cfg.coherent_walk = false;
 449         domain->cfg.iommu_dev = domain->mmu->root->dev;
 450
 451         /*
 452          * Find an unused context.
 453          */
 454         ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
 455         if (ret < 0)
 456                 return ret;
 457
 458         domain->context_id = ret;
 459
 460         domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 461                                            domain);
 462         if (!domain->iop) {
 463                 ipmmu_domain_free_context(domain->mmu->root,
 464                                           domain->context_id);
 465                 return -EINVAL;
 466         }
 467
 468         ipmmu_domain_setup_context(domain);
 469         return 0;
 470 }
 471
 472 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 473 {
 474         if (!domain->mmu)
 475                 return;
 476
 477         /*
 478          * Disable the context. Flush the TLB as required when modifying the
 479          * context registers.
 480          *
 481          * TODO: Is TLB flush really needed ?
 482          */
 483         ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
 484         ipmmu_tlb_sync(domain);
 485         ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
 486 }
 487
 488 /* -----------------------------------------------------------------------------
 489  * Fault Handling
 490  */
 491
 492 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 493 {
 494         const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
 495         struct ipmmu_vmsa_device *mmu = domain->mmu;
 496         unsigned long iova;
 497         u32 status;
 498
 499         status = ipmmu_ctx_read_root(domain, IMSTR);
 500         if (!(status & err_mask))
 501                 return IRQ_NONE;
 502
 503         iova = ipmmu_ctx_read_root(domain, IMELAR);
 504         if (IS_ENABLED(CONFIG_64BIT))
 505                 iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
 506
 507         /*
 508          * Clear the error status flags. Unlike traditional interrupt flag
 509          * registers that must be cleared by writing 1, this status register
 510          * seems to require 0. The error address register must be read before,
 511          * otherwise its value will be 0.
 512          */
 513         ipmmu_ctx_write_root(domain, IMSTR, 0);
 514
 515         /* Log fatal errors. */
 516         if (status & IMSTR_MHIT)
 517                 dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
 518                                     iova);
 519         if (status & IMSTR_ABORT)
 520                 dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
 521                                     iova);
 522
 523         if (!(status & (IMSTR_PF | IMSTR_TF)))
 524                 return IRQ_NONE;
 525
 526         /*
 527          * Try to handle page faults and translation faults.
 528          *
 529          * TODO: We need to look up the faulty device based on the I/O VA. Use
 530          * the IOMMU device for now.
 531          */
 532         if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
 533                 return IRQ_HANDLED;
 534
 535         dev_err_ratelimited(mmu->dev,
 536                             "Unhandled fault: status 0x%08x iova 0x%lx\n",
 537                             status, iova);
 538
 539         return IRQ_HANDLED;
 540 }
 541
 542 static irqreturn_t ipmmu_irq(int irq, void *dev)
 543 {
 544         struct ipmmu_vmsa_device *mmu = dev;
 545         irqreturn_t status = IRQ_NONE;
 546         unsigned int i;
 547         unsigned long flags;
 548
 549         spin_lock_irqsave(&mmu->lock, flags);
 550
 551         /*
 552          * Check interrupts for all active contexts.
 553          */
 554         for (i = 0; i < mmu->num_ctx; i++) {
 555                 if (!mmu->domains[i])
 556                         continue;
 557                 if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
 558                         status = IRQ_HANDLED;
 559         }
 560
 561         spin_unlock_irqrestore(&mmu->lock, flags);
 562
 563         return status;
 564 }
 565
 566 /* -----------------------------------------------------------------------------
 567  * IOMMU Operations
 568  */
 569
 570 static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
 571 {
 572         struct ipmmu_vmsa_domain *domain;
 573
 574         if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
 575                 return NULL;
 576
 577         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 578         if (!domain)
 579                 return NULL;
 580
 581         mutex_init(&domain->mutex);
 582
 583         return &domain->io_domain;
 584 }
 585
 586 static void ipmmu_domain_free(struct iommu_domain *io_domain)
 587 {
 588         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 589
 590         /*
 591          * Free the domain resources. We assume that all devices have already
 592          * been detached.
 593          */
 594         ipmmu_domain_destroy_context(domain);
 595         free_io_pgtable_ops(domain->iop);
 596         kfree(domain);
 597 }
 598
 599 static int ipmmu_attach_device(struct iommu_domain *io_domain,
 600                                struct device *dev)
 601 {
 602         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 603         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 604         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 605         unsigned int i;
 606         int ret = 0;
 607
 608         if (!mmu) {
 609                 dev_err(dev, "Cannot attach to IPMMU\n");
 610                 return -ENXIO;
 611         }
 612
 613         mutex_lock(&domain->mutex);
 614
 615         if (!domain->mmu) {
 616                 /* The domain hasn't been used yet, initialize it. */
 617                 domain->mmu = mmu;
 618                 ret = ipmmu_domain_init_context(domain);
 619                 if (ret < 0) {
 620                         dev_err(dev, "Unable to initialize IPMMU context\n");
 621                         domain->mmu = NULL;
 622                 } else {
 623                         dev_info(dev, "Using IPMMU context %u\n",
 624                                  domain->context_id);
 625                 }
 626         } else if (domain->mmu != mmu) {
 627                 /*
 628                  * Something is wrong, we can't attach two devices using
 629                  * different IOMMUs to the same domain.
 630                  */
 631                 dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
 632                         dev_name(mmu->dev), dev_name(domain->mmu->dev));
 633                 ret = -EINVAL;
 634         } else
 635                 dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
 636
 637         mutex_unlock(&domain->mutex);
 638
 639         if (ret < 0)
 640                 return ret;
 641
 642         for (i = 0; i < fwspec->num_ids; ++i)
 643                 ipmmu_utlb_enable(domain, fwspec->ids[i]);
 644
 645         return 0;
 646 }
 647
 648 static void ipmmu_detach_device(struct iommu_domain *io_domain,
 649                                 struct device *dev)
 650 {
 651         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 652         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 653         unsigned int i;
 654
 655         for (i = 0; i < fwspec->num_ids; ++i)
 656                 ipmmu_utlb_disable(domain, fwspec->ids[i]);
 657
 658         /*
 659          * TODO: Optimize by disabling the context when no device is attached.
 660          */
 661 }
 662
 663 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 664                      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 665 {
 666         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 667
 668         if (!domain)
 669                 return -ENODEV;
 670
 671         return domain->iop->map(domain->iop, iova, paddr, size, prot, gfp);
 672 }
 673
 674 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
 675                           size_t size, struct iommu_iotlb_gather *gather)
 676 {
 677         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 678
 679         return domain->iop->unmap(domain->iop, iova, size, gather);
 680 }
 681
 682 static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
 683 {
 684         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 685
 686         if (domain->mmu)
 687                 ipmmu_tlb_flush_all(domain);
 688 }
 689
 690 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
 691                              struct iommu_iotlb_gather *gather)
 692 {
 693         ipmmu_flush_iotlb_all(io_domain);
 694 }
 695
 696 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 697                                       dma_addr_t iova)
 698 {
 699         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 700
 701         /* TODO: Is locking needed ? */
 702
 703         return domain->iop->iova_to_phys(domain->iop, iova);
 704 }
 705
 706 static int ipmmu_init_platform_device(struct device *dev,
 707                                       struct of_phandle_args *args)
 708 {
 709         struct platform_device *ipmmu_pdev;
 710
 711         ipmmu_pdev = of_find_device_by_node(args->np);
 712         if (!ipmmu_pdev)
 713                 return -ENODEV;
 714
 715         dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
 716
 717         return 0;
 718 }
 719
 720 static const struct soc_device_attribute soc_needs_opt_in[] = {
 721         { .family = "R-Car Gen3", },
 722         { .family = "R-Car Gen4", },
 723         { .family = "RZ/G2", },
 724         { /* sentinel */ }
 725 };
 726
 727 static const struct soc_device_attribute soc_denylist[] = {
 728         { .soc_id = "r8a774a1", },
 729         { .soc_id = "r8a7795", .revision = "ES1.*" },
 730         { .soc_id = "r8a7795", .revision = "ES2.*" },
 731         { .soc_id = "r8a7796", },
 732         { /* sentinel */ }
 733 };
 734
 735 static const char * const devices_allowlist[] = {
 736         "ee100000.mmc",
 737         "ee120000.mmc",
 738         "ee140000.mmc",
 739         "ee160000.mmc"
 740 };
 741
 742 static bool ipmmu_device_is_allowed(struct device *dev)
 743 {
 744         unsigned int i;
 745
 746         /*
 747          * R-Car Gen3/4 and RZ/G2 use the allow list to opt-in devices.
 748          * For Other SoCs, this returns true anyway.
 749          */
 750         if (!soc_device_match(soc_needs_opt_in))
 751                 return true;
 752
 753         /* Check whether this SoC can use the IPMMU correctly or not */
 754         if (soc_device_match(soc_denylist))
 755                 return false;
 756
 757         /* Check whether this device can work with the IPMMU */
 758         for (i = 0; i < ARRAY_SIZE(devices_allowlist); i++) {
 759                 if (!strcmp(dev_name(dev), devices_allowlist[i]))
 760                         return true;
 761         }
 762
 763         /* Otherwise, do not allow use of IPMMU */
 764         return false;
 765 }
 766
 767 static int ipmmu_of_xlate(struct device *dev,
 768                           struct of_phandle_args *spec)
 769 {
 770         if (!ipmmu_device_is_allowed(dev))
 771                 return -ENODEV;
 772
 773         iommu_fwspec_add_ids(dev, spec->args, 1);
 774
 775         /* Initialize once - xlate() will call multiple times */
 776         if (to_ipmmu(dev))
 777                 return 0;
 778
 779         return ipmmu_init_platform_device(dev, spec);
 780 }
 781
 782 static int ipmmu_init_arm_mapping(struct device *dev)
 783 {
 784         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 785         int ret;
 786
 787         /*
 788          * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 789          * VAs. This will allocate a corresponding IOMMU domain.
 790          *
 791          * TODO:
 792          * - Create one mapping per context (TLB).
 793          * - Make the mapping size configurable ? We currently use a 2GB mapping
 794          *   at a 1GB offset to ensure that NULL VAs will fault.
 795          */
 796         if (!mmu->mapping) {
 797                 struct dma_iommu_mapping *mapping;
 798
 799                 mapping = arm_iommu_create_mapping(&platform_bus_type,
 800                                                    SZ_1G, SZ_2G);
 801                 if (IS_ERR(mapping)) {
 802                         dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 803                         ret = PTR_ERR(mapping);
 804                         goto error;
 805                 }
 806
 807                 mmu->mapping = mapping;
 808         }
 809
 810         /* Attach the ARM VA mapping to the device. */
 811         ret = arm_iommu_attach_device(dev, mmu->mapping);
 812         if (ret < 0) {
 813                 dev_err(dev, "Failed to attach device to VA mapping\n");
 814                 goto error;
 815         }
 816
 817         return 0;
 818
 819 error:
 820         if (mmu->mapping)
 821                 arm_iommu_release_mapping(mmu->mapping);
 822
 823         return ret;
 824 }
 825
 826 static struct iommu_device *ipmmu_probe_device(struct device *dev)
 827 {
 828         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 829
 830         /*
 831          * Only let through devices that have been verified in xlate()
 832          */
 833         if (!mmu)
 834                 return ERR_PTR(-ENODEV);
 835
 836         return &mmu->iommu;
 837 }
 838
 839 static void ipmmu_probe_finalize(struct device *dev)
 840 {
 841         int ret = 0;
 842
 843         if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
 844                 ret = ipmmu_init_arm_mapping(dev);
 845
 846         if (ret)
 847                 dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
 848 }
 849
 850 static void ipmmu_release_device(struct device *dev)
 851 {
 852         arm_iommu_detach_device(dev);
 853 }
 854
 855 static struct iommu_group *ipmmu_find_group(struct device *dev)
 856 {
 857         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 858         struct iommu_group *group;
 859
 860         if (mmu->group)
 861                 return iommu_group_ref_get(mmu->group);
 862
 863         group = iommu_group_alloc();
 864         if (!IS_ERR(group))
 865                 mmu->group = group;
 866
 867         return group;
 868 }
 869
 870 static const struct iommu_ops ipmmu_ops = {
 871         .domain_alloc = ipmmu_domain_alloc,
 872         .probe_device = ipmmu_probe_device,
 873         .release_device = ipmmu_release_device,
 874         .probe_finalize = ipmmu_probe_finalize,
 875         .device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
 876                         ? generic_device_group : ipmmu_find_group,
 877         .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 878         .of_xlate = ipmmu_of_xlate,
 879         .default_domain_ops = &(const struct iommu_domain_ops) {
 880                 .attach_dev     = ipmmu_attach_device,
 881                 .detach_dev     = ipmmu_detach_device,
 882                 .map            = ipmmu_map,
 883                 .unmap          = ipmmu_unmap,
 884                 .flush_iotlb_all = ipmmu_flush_iotlb_all,
 885                 .iotlb_sync     = ipmmu_iotlb_sync,
 886                 .iova_to_phys   = ipmmu_iova_to_phys,
 887                 .free           = ipmmu_domain_free,
 888         }
 889 };
 890
 891 /* -----------------------------------------------------------------------------
 892  * Probe/remove and init
 893  */
 894
 895 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 896 {
 897         unsigned int i;
 898
 899         /* Disable all contexts. */
 900         for (i = 0; i < mmu->num_ctx; ++i)
 901                 ipmmu_ctx_write(mmu, i, IMCTR, 0);
 902 }
 903
 904 static const struct ipmmu_features ipmmu_features_default = {
 905         .use_ns_alias_offset = true,
 906         .has_cache_leaf_nodes = false,
 907         .number_of_contexts = 1, /* software only tested with one context */
 908         .num_utlbs = 32,
 909         .setup_imbuscr = true,
 910         .twobit_imttbcr_sl0 = false,
 911         .reserved_context = false,
 912         .cache_snoop = true,
 913         .ctx_offset_base = 0,
 914         .ctx_offset_stride = 0x40,
 915         .utlb_offset_base = 0,
 916 };
 917
 918 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 919         .use_ns_alias_offset = false,
 920         .has_cache_leaf_nodes = true,
 921         .number_of_contexts = 8,
 922         .num_utlbs = 48,
 923         .setup_imbuscr = false,
 924         .twobit_imttbcr_sl0 = true,
 925         .reserved_context = true,
 926         .cache_snoop = false,
 927         .ctx_offset_base = 0,
 928         .ctx_offset_stride = 0x40,
 929         .utlb_offset_base = 0,
 930 };
 931
 932 static const struct ipmmu_features ipmmu_features_rcar_gen4 = {
 933         .use_ns_alias_offset = false,
 934         .has_cache_leaf_nodes = true,
 935         .number_of_contexts = 16,
 936         .num_utlbs = 64,
 937         .setup_imbuscr = false,
 938         .twobit_imttbcr_sl0 = true,
 939         .reserved_context = true,
 940         .cache_snoop = false,
 941         .ctx_offset_base = 0x10000,
 942         .ctx_offset_stride = 0x1040,
 943         .utlb_offset_base = 0x3000,
 944 };
 945
 946 static const struct of_device_id ipmmu_of_ids[] = {
 947         {
 948                 .compatible = "renesas,ipmmu-vmsa",
 949                 .data = &ipmmu_features_default,
 950         }, {
 951                 .compatible = "renesas,ipmmu-r8a774a1",
 952                 .data = &ipmmu_features_rcar_gen3,
 953         }, {
 954                 .compatible = "renesas,ipmmu-r8a774b1",
 955                 .data = &ipmmu_features_rcar_gen3,
 956         }, {
 957                 .compatible = "renesas,ipmmu-r8a774c0",
 958                 .data = &ipmmu_features_rcar_gen3,
 959         }, {
 960                 .compatible = "renesas,ipmmu-r8a774e1",
 961                 .data = &ipmmu_features_rcar_gen3,
 962         }, {
 963                 .compatible = "renesas,ipmmu-r8a7795",
 964                 .data = &ipmmu_features_rcar_gen3,
 965         }, {
 966                 .compatible = "renesas,ipmmu-r8a7796",
 967                 .data = &ipmmu_features_rcar_gen3,
 968         }, {
 969                 .compatible = "renesas,ipmmu-r8a77961",
 970                 .data = &ipmmu_features_rcar_gen3,
 971         }, {
 972                 .compatible = "renesas,ipmmu-r8a77965",
 973                 .data = &ipmmu_features_rcar_gen3,
 974         }, {
 975                 .compatible = "renesas,ipmmu-r8a77970",
 976                 .data = &ipmmu_features_rcar_gen3,
 977         }, {
 978                 .compatible = "renesas,ipmmu-r8a77980",
 979                 .data = &ipmmu_features_rcar_gen3,
 980         }, {
 981                 .compatible = "renesas,ipmmu-r8a77990",
 982                 .data = &ipmmu_features_rcar_gen3,
 983         }, {
 984                 .compatible = "renesas,ipmmu-r8a77995",
 985                 .data = &ipmmu_features_rcar_gen3,
 986         }, {
 987                 .compatible = "renesas,ipmmu-r8a779a0",
 988                 .data = &ipmmu_features_rcar_gen4,
 989         }, {
 990                 .compatible = "renesas,rcar-gen4-ipmmu-vmsa",
 991                 .data = &ipmmu_features_rcar_gen4,
 992         }, {
 993                 /* Terminator */
 994         },
 995 };
 996
 997 static int ipmmu_probe(struct platform_device *pdev)
 998 {
 999         struct ipmmu_vmsa_device *mmu;
1000         struct resource *res;
1001         int irq;
1002         int ret;
1003
1004         mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
1005         if (!mmu) {
1006                 dev_err(&pdev->dev, "cannot allocate device data\n");
1007                 return -ENOMEM;
1008         }
1009
1010         mmu->dev = &pdev->dev;
1011         spin_lock_init(&mmu->lock);
1012         bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
1013         mmu->features = of_device_get_match_data(&pdev->dev);
1014         memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs);
1015         ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
1016         if (ret)
1017                 return ret;
1018
1019         /* Map I/O memory and request IRQ. */
1020         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1021         mmu->base = devm_ioremap_resource(&pdev->dev, res);
1022         if (IS_ERR(mmu->base))
1023                 return PTR_ERR(mmu->base);
1024
1025         /*
1026          * The IPMMU has two register banks, for secure and non-secure modes.
1027          * The bank mapped at the beginning of the IPMMU address space
1028          * corresponds to the running mode of the CPU. When running in secure
1029          * mode the non-secure register bank is also available at an offset.
1030          *
1031          * Secure mode operation isn't clearly documented and is thus currently
1032          * not implemented in the driver. Furthermore, preliminary tests of
1033          * non-secure operation with the main register bank were not successful.
1034          * Offset the registers base unconditionally to point to the non-secure
1035          * alias space for now.
1036          */
1037         if (mmu->features->use_ns_alias_offset)
1038                 mmu->base += IM_NS_ALIAS_OFFSET;
1039
1040         mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1041
1042         /*
1043          * Determine if this IPMMU instance is a root device by checking for
1044          * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1045          */
1046         if (!mmu->features->has_cache_leaf_nodes ||
1047             !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
1048                 mmu->root = mmu;
1049         else
1050                 mmu->root = ipmmu_find_root();
1051
1052         /*
1053          * Wait until the root device has been registered for sure.
1054          */
1055         if (!mmu->root)
1056                 return -EPROBE_DEFER;
1057
1058         /* Root devices have mandatory IRQs */
1059         if (ipmmu_is_root(mmu)) {
1060                 irq = platform_get_irq(pdev, 0);
1061                 if (irq < 0)
1062                         return irq;
1063
1064                 ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1065                                        dev_name(&pdev->dev), mmu);
1066                 if (ret < 0) {
1067                         dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1068                         return ret;
1069                 }
1070
1071                 ipmmu_device_reset(mmu);
1072
1073                 if (mmu->features->reserved_context) {
1074                         dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1075                         set_bit(0, mmu->ctx);
1076                 }
1077         }
1078
1079         /*
1080          * Register the IPMMU to the IOMMU subsystem in the following cases:
1081          * - R-Car Gen2 IPMMU (all devices registered)
1082          * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1083          */
1084         if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1085                 ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1086                                              dev_name(&pdev->dev));
1087                 if (ret)
1088                         return ret;
1089
1090                 ret = iommu_device_register(&mmu->iommu, &ipmmu_ops, &pdev->dev);
1091                 if (ret)
1092                         return ret;
1093
1094 #if defined(CONFIG_IOMMU_DMA)
1095                 if (!iommu_present(&platform_bus_type))
1096                         bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1097 #endif
1098         }
1099
1100         /*
1101          * We can't create the ARM mapping here as it requires the bus to have
1102          * an IOMMU, which only happens when bus_set_iommu() is called in
1103          * ipmmu_init() after the probe function returns.
1104          */
1105
1106         platform_set_drvdata(pdev, mmu);
1107
1108         return 0;
1109 }
1110
1111 static int ipmmu_remove(struct platform_device *pdev)
1112 {
1113         struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1114
1115         iommu_device_sysfs_remove(&mmu->iommu);
1116         iommu_device_unregister(&mmu->iommu);
1117
1118         arm_iommu_release_mapping(mmu->mapping);
1119
1120         ipmmu_device_reset(mmu);
1121
1122         return 0;
1123 }
1124
1125 #ifdef CONFIG_PM_SLEEP
1126 static int ipmmu_resume_noirq(struct device *dev)
1127 {
1128         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1129         unsigned int i;
1130
1131         /* Reset root MMU and restore contexts */
1132         if (ipmmu_is_root(mmu)) {
1133                 ipmmu_device_reset(mmu);
1134
1135                 for (i = 0; i < mmu->num_ctx; i++) {
1136                         if (!mmu->domains[i])
1137                                 continue;
1138
1139                         ipmmu_domain_setup_context(mmu->domains[i]);
1140                 }
1141         }
1142
1143         /* Re-enable active micro-TLBs */
1144         for (i = 0; i < mmu->features->num_utlbs; i++) {
1145                 if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1146                         continue;
1147
1148                 ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1149         }
1150
1151         return 0;
1152 }
1153
1154 static const struct dev_pm_ops ipmmu_pm  = {
1155         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1156 };
1157 #define DEV_PM_OPS      &ipmmu_pm
1158 #else
1159 #define DEV_PM_OPS      NULL
1160 #endif /* CONFIG_PM_SLEEP */
1161
1162 static struct platform_driver ipmmu_driver = {
1163         .driver = {
1164                 .name = "ipmmu-vmsa",
1165                 .of_match_table = of_match_ptr(ipmmu_of_ids),
1166                 .pm = DEV_PM_OPS,
1167         },
1168         .probe = ipmmu_probe,
1169         .remove = ipmmu_remove,
1170 };
1171
1172 static int __init ipmmu_init(void)
1173 {
1174         struct device_node *np;
1175         static bool setup_done;
1176         int ret;
1177
1178         if (setup_done)
1179                 return 0;
1180
1181         np = of_find_matching_node(NULL, ipmmu_of_ids);
1182         if (!np)
1183                 return 0;
1184
1185         of_node_put(np);
1186
1187         ret = platform_driver_register(&ipmmu_driver);
1188         if (ret < 0)
1189                 return ret;
1190
1191 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
1192         if (!iommu_present(&platform_bus_type))
1193                 bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1194 #endif
1195
1196         setup_done = true;
1197         return 0;
1198 }
1199 subsys_initcall(ipmmu_init);