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 Renesas Electronics Corporation
   7  */
   8
   9 #include <linux/bitmap.h>
  10 #include <linux/delay.h>
  11 #include <linux/dma-iommu.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/err.h>
  14 #include <linux/export.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/io.h>
  18 #include <linux/io-pgtable.h>
  19 #include <linux/iommu.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/of_iommu.h>
  23 #include <linux/of_platform.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/sizes.h>
  26 #include <linux/slab.h>
  27 #include <linux/sys_soc.h>
  28
  29 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
  30 #include <asm/dma-iommu.h>
  31 #include <asm/pgalloc.h>
  32 #else
  33 #define arm_iommu_create_mapping(...)   NULL
  34 #define arm_iommu_attach_device(...)    -ENODEV
  35 #define arm_iommu_release_mapping(...)  do {} while (0)
  36 #define arm_iommu_detach_device(...)    do {} while (0)
  37 #endif
  38
  39 #define IPMMU_CTX_MAX           8U
  40 #define IPMMU_CTX_INVALID       -1
  41
  42 #define IPMMU_UTLB_MAX          48U
  43
  44 struct ipmmu_features {
  45         bool use_ns_alias_offset;
  46         bool has_cache_leaf_nodes;
  47         unsigned int number_of_contexts;
  48         unsigned int num_utlbs;
  49         bool setup_imbuscr;
  50         bool twobit_imttbcr_sl0;
  51         bool reserved_context;
  52         bool cache_snoop;
  53         unsigned int ctx_offset_base;
  54         unsigned int ctx_offset_stride;
  55         unsigned int utlb_offset_base;
  56 };
  57
  58 struct ipmmu_vmsa_device {
  59         struct device *dev;
  60         void __iomem *base;
  61         struct iommu_device iommu;
  62         struct ipmmu_vmsa_device *root;
  63         const struct ipmmu_features *features;
  64         unsigned int num_ctx;
  65         spinlock_t lock;                        /* Protects ctx and domains[] */
  66         DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
  67         struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
  68         s8 utlb_ctx[IPMMU_UTLB_MAX];
  69
  70         struct iommu_group *group;
  71         struct dma_iommu_mapping *mapping;
  72 };
  73
  74 struct ipmmu_vmsa_domain {
  75         struct ipmmu_vmsa_device *mmu;
  76         struct iommu_domain io_domain;
  77
  78         struct io_pgtable_cfg cfg;
  79         struct io_pgtable_ops *iop;
  80
  81         unsigned int context_id;
  82         struct mutex mutex;                     /* Protects mappings */
  83 };
  84
  85 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
  86 {
  87         return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
  88 }
  89
  90 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
  91 {
  92         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
  93
  94         return fwspec ? fwspec->iommu_priv : NULL;
  95 }
  96
  97 #define TLB_LOOP_TIMEOUT                100     /* 100us */
  98
  99 /* -----------------------------------------------------------------------------
 100  * Registers Definition
 101  */
 102
 103 #define IM_NS_ALIAS_OFFSET              0x800
 104
 105 /* MMU "context" registers */
 106 #define IMCTR                           0x0000          /* R-Car Gen2/3 */
 107 #define IMCTR_INTEN                     (1 << 2)        /* R-Car Gen2/3 */
 108 #define IMCTR_FLUSH                     (1 << 1)        /* R-Car Gen2/3 */
 109 #define IMCTR_MMUEN                     (1 << 0)        /* R-Car Gen2/3 */
 110
 111 #define IMTTBCR                         0x0008          /* R-Car Gen2/3 */
 112 #define IMTTBCR_EAE                     (1 << 31)       /* R-Car Gen2/3 */
 113 #define IMTTBCR_SH0_INNER_SHAREABLE     (3 << 12)       /* R-Car Gen2 only */
 114 #define IMTTBCR_ORGN0_WB_WA             (1 << 10)       /* R-Car Gen2 only */
 115 #define IMTTBCR_IRGN0_WB_WA             (1 << 8)        /* R-Car Gen2 only */
 116 #define IMTTBCR_SL0_TWOBIT_LVL_1        (2 << 6)        /* R-Car Gen3 only */
 117 #define IMTTBCR_SL0_LVL_1               (1 << 4)        /* R-Car Gen2 only */
 118
 119 #define IMBUSCR                         0x000c          /* R-Car Gen2 only */
 120 #define IMBUSCR_DVM                     (1 << 2)        /* R-Car Gen2 only */
 121 #define IMBUSCR_BUSSEL_MASK             (3 << 0)        /* R-Car Gen2 only */
 122
 123 #define IMTTLBR0                        0x0010          /* R-Car Gen2/3 */
 124 #define IMTTUBR0                        0x0014          /* R-Car Gen2/3 */
 125
 126 #define IMSTR                           0x0020          /* R-Car Gen2/3 */
 127 #define IMSTR_MHIT                      (1 << 4)        /* R-Car Gen2/3 */
 128 #define IMSTR_ABORT                     (1 << 2)        /* R-Car Gen2/3 */
 129 #define IMSTR_PF                        (1 << 1)        /* R-Car Gen2/3 */
 130 #define IMSTR_TF                        (1 << 0)        /* R-Car Gen2/3 */
 131
 132 #define IMMAIR0                         0x0028          /* R-Car Gen2/3 */
 133
 134 #define IMELAR                          0x0030          /* R-Car Gen2/3, IMEAR on R-Car Gen2 */
 135 #define IMEUAR                          0x0034          /* R-Car Gen3 only */
 136
 137 /* uTLB registers */
 138 #define IMUCTR(n)                       ((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
 139 #define IMUCTR0(n)                      (0x0300 + ((n) * 16))           /* R-Car Gen2/3 */
 140 #define IMUCTR32(n)                     (0x0600 + (((n) - 32) * 16))    /* R-Car Gen3 only */
 141 #define IMUCTR_TTSEL_MMU(n)             ((n) << 4)      /* R-Car Gen2/3 */
 142 #define IMUCTR_FLUSH                    (1 << 1)        /* R-Car Gen2/3 */
 143 #define IMUCTR_MMUEN                    (1 << 0)        /* R-Car Gen2/3 */
 144
 145 #define IMUASID(n)                      ((n) < 32 ? IMUASID0(n) : IMUASID32(n))
 146 #define IMUASID0(n)                     (0x0308 + ((n) * 16))           /* R-Car Gen2/3 */
 147 #define IMUASID32(n)                    (0x0608 + (((n) - 32) * 16))    /* R-Car Gen3 only */
 148
 149 /* -----------------------------------------------------------------------------
 150  * Root device handling
 151  */
 152
 153 static struct platform_driver ipmmu_driver;
 154
 155 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
 156 {
 157         return mmu->root == mmu;
 158 }
 159
 160 static int __ipmmu_check_device(struct device *dev, void *data)
 161 {
 162         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
 163         struct ipmmu_vmsa_device **rootp = data;
 164
 165         if (ipmmu_is_root(mmu))
 166                 *rootp = mmu;
 167
 168         return 0;
 169 }
 170
 171 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
 172 {
 173         struct ipmmu_vmsa_device *root = NULL;
 174
 175         return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
 176                                       __ipmmu_check_device) == 0 ? root : NULL;
 177 }
 178
 179 /* -----------------------------------------------------------------------------
 180  * Read/Write Access
 181  */
 182
 183 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
 184 {
 185         return ioread32(mmu->base + offset);
 186 }
 187
 188 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 189                         u32 data)
 190 {
 191         iowrite32(data, mmu->base + offset);
 192 }
 193
 194 static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
 195                                   unsigned int context_id, unsigned int reg)
 196 {
 197         return mmu->features->ctx_offset_base +
 198                context_id * mmu->features->ctx_offset_stride + reg;
 199 }
 200
 201 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
 202                           unsigned int context_id, unsigned int reg)
 203 {
 204         return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
 205 }
 206
 207 static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
 208                             unsigned int context_id, unsigned int reg, u32 data)
 209 {
 210         ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
 211 }
 212
 213 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 214                                unsigned int reg)
 215 {
 216         return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
 217 }
 218
 219 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 220                                  unsigned int reg, u32 data)
 221 {
 222         ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 223 }
 224
 225 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 226                                 unsigned int reg, u32 data)
 227 {
 228         if (domain->mmu != domain->mmu->root)
 229                 ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
 230
 231         ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 232 }
 233
 234 static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
 235 {
 236         return mmu->features->utlb_offset_base + reg;
 237 }
 238
 239 static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
 240                                 unsigned int utlb, u32 data)
 241 {
 242         ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
 243 }
 244
 245 static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
 246                                unsigned int utlb, u32 data)
 247 {
 248         ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
 249 }
 250
 251 /* -----------------------------------------------------------------------------
 252  * TLB and microTLB Management
 253  */
 254
 255 /* Wait for any pending TLB invalidations to complete */
 256 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
 257 {
 258         unsigned int count = 0;
 259
 260         while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
 261                 cpu_relax();
 262                 if (++count == TLB_LOOP_TIMEOUT) {
 263                         dev_err_ratelimited(domain->mmu->dev,
 264                         "TLB sync timed out -- MMU may be deadlocked\n");
 265                         return;
 266                 }
 267                 udelay(1);
 268         }
 269 }
 270
 271 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
 272 {
 273         u32 reg;
 274
 275         reg = ipmmu_ctx_read_root(domain, IMCTR);
 276         reg |= IMCTR_FLUSH;
 277         ipmmu_ctx_write_all(domain, IMCTR, reg);
 278
 279         ipmmu_tlb_sync(domain);
 280 }
 281
 282 /*
 283  * Enable MMU translation for the microTLB.
 284  */
 285 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 286                               unsigned int utlb)
 287 {
 288         struct ipmmu_vmsa_device *mmu = domain->mmu;
 289
 290         /*
 291          * TODO: Reference-count the microTLB as several bus masters can be
 292          * connected to the same microTLB.
 293          */
 294
 295         /* TODO: What should we set the ASID to ? */
 296         ipmmu_imuasid_write(mmu, utlb, 0);
 297         /* TODO: Do we need to flush the microTLB ? */
 298         ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
 299                                       IMUCTR_FLUSH | IMUCTR_MMUEN);
 300         mmu->utlb_ctx[utlb] = domain->context_id;
 301 }
 302
 303 /*
 304  * Disable MMU translation for the microTLB.
 305  */
 306 static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 307                                unsigned int utlb)
 308 {
 309         struct ipmmu_vmsa_device *mmu = domain->mmu;
 310
 311         ipmmu_imuctr_write(mmu, utlb, 0);
 312         mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
 313 }
 314
 315 static void ipmmu_tlb_flush_all(void *cookie)
 316 {
 317         struct ipmmu_vmsa_domain *domain = cookie;
 318
 319         ipmmu_tlb_invalidate(domain);
 320 }
 321
 322 static void ipmmu_tlb_flush(unsigned long iova, size_t size,
 323                                 size_t granule, void *cookie)
 324 {
 325         ipmmu_tlb_flush_all(cookie);
 326 }
 327
 328 static const struct iommu_flush_ops ipmmu_flush_ops = {
 329         .tlb_flush_all = ipmmu_tlb_flush_all,
 330         .tlb_flush_walk = ipmmu_tlb_flush,
 331         .tlb_flush_leaf = ipmmu_tlb_flush,
 332 };
 333
 334 /* -----------------------------------------------------------------------------
 335  * Domain/Context Management
 336  */
 337
 338 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
 339                                          struct ipmmu_vmsa_domain *domain)
 340 {
 341         unsigned long flags;
 342         int ret;
 343
 344         spin_lock_irqsave(&mmu->lock, flags);
 345
 346         ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
 347         if (ret != mmu->num_ctx) {
 348                 mmu->domains[ret] = domain;
 349                 set_bit(ret, mmu->ctx);
 350         } else
 351                 ret = -EBUSY;
 352
 353         spin_unlock_irqrestore(&mmu->lock, flags);
 354
 355         return ret;
 356 }
 357
 358 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 359                                       unsigned int context_id)
 360 {
 361         unsigned long flags;
 362
 363         spin_lock_irqsave(&mmu->lock, flags);
 364
 365         clear_bit(context_id, mmu->ctx);
 366         mmu->domains[context_id] = NULL;
 367
 368         spin_unlock_irqrestore(&mmu->lock, flags);
 369 }
 370
 371 static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
 372 {
 373         u64 ttbr;
 374         u32 tmp;
 375
 376         /* TTBR0 */
 377         ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
 378         ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
 379         ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 380
 381         /*
 382          * TTBCR
 383          * We use long descriptors and allocate the whole 32-bit VA space to
 384          * TTBR0.
 385          */
 386         if (domain->mmu->features->twobit_imttbcr_sl0)
 387                 tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
 388         else
 389                 tmp = IMTTBCR_SL0_LVL_1;
 390
 391         if (domain->mmu->features->cache_snoop)
 392                 tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
 393                        IMTTBCR_IRGN0_WB_WA;
 394
 395         ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
 396
 397         /* MAIR0 */
 398         ipmmu_ctx_write_root(domain, IMMAIR0,
 399                              domain->cfg.arm_lpae_s1_cfg.mair);
 400
 401         /* IMBUSCR */
 402         if (domain->mmu->features->setup_imbuscr)
 403                 ipmmu_ctx_write_root(domain, IMBUSCR,
 404                                      ipmmu_ctx_read_root(domain, IMBUSCR) &
 405                                      ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 406
 407         /*
 408          * IMSTR
 409          * Clear all interrupt flags.
 410          */
 411         ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
 412
 413         /*
 414          * IMCTR
 415          * Enable the MMU and interrupt generation. The long-descriptor
 416          * translation table format doesn't use TEX remapping. Don't enable AF
 417          * software management as we have no use for it. Flush the TLB as
 418          * required when modifying the context registers.
 419          */
 420         ipmmu_ctx_write_all(domain, IMCTR,
 421                             IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 422 }
 423
 424 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 425 {
 426         int ret;
 427
 428         /*
 429          * Allocate the page table operations.
 430          *
 431          * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
 432          * access, Long-descriptor format" that the NStable bit being set in a
 433          * table descriptor will result in the NStable and NS bits of all child
 434          * entries being ignored and considered as being set. The IPMMU seems
 435          * not to comply with this, as it generates a secure access page fault
 436          * if any of the NStable and NS bits isn't set when running in
 437          * non-secure mode.
 438          */
 439         domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
 440         domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
 441         domain->cfg.ias = 32;
 442         domain->cfg.oas = 40;
 443         domain->cfg.tlb = &ipmmu_flush_ops;
 444         domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
 445         domain->io_domain.geometry.force_aperture = true;
 446         /*
 447          * TODO: Add support for coherent walk through CCI with DVM and remove
 448          * cache handling. For now, delegate it to the io-pgtable code.
 449          */
 450         domain->cfg.coherent_walk = false;
 451         domain->cfg.iommu_dev = domain->mmu->root->dev;
 452
 453         /*
 454          * Find an unused context.
 455          */
 456         ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
 457         if (ret < 0)
 458                 return ret;
 459
 460         domain->context_id = ret;
 461
 462         domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 463                                            domain);
 464         if (!domain->iop) {
 465                 ipmmu_domain_free_context(domain->mmu->root,
 466                                           domain->context_id);
 467                 return -EINVAL;
 468         }
 469
 470         ipmmu_domain_setup_context(domain);
 471         return 0;
 472 }
 473
 474 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 475 {
 476         if (!domain->mmu)
 477                 return;
 478
 479         /*
 480          * Disable the context. Flush the TLB as required when modifying the
 481          * context registers.
 482          *
 483          * TODO: Is TLB flush really needed ?
 484          */
 485         ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
 486         ipmmu_tlb_sync(domain);
 487         ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
 488 }
 489
 490 /* -----------------------------------------------------------------------------
 491  * Fault Handling
 492  */
 493
 494 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 495 {
 496         const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
 497         struct ipmmu_vmsa_device *mmu = domain->mmu;
 498         unsigned long iova;
 499         u32 status;
 500
 501         status = ipmmu_ctx_read_root(domain, IMSTR);
 502         if (!(status & err_mask))
 503                 return IRQ_NONE;
 504
 505         iova = ipmmu_ctx_read_root(domain, IMELAR);
 506         if (IS_ENABLED(CONFIG_64BIT))
 507                 iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
 508
 509         /*
 510          * Clear the error status flags. Unlike traditional interrupt flag
 511          * registers that must be cleared by writing 1, this status register
 512          * seems to require 0. The error address register must be read before,
 513          * otherwise its value will be 0.
 514          */
 515         ipmmu_ctx_write_root(domain, IMSTR, 0);
 516
 517         /* Log fatal errors. */
 518         if (status & IMSTR_MHIT)
 519                 dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
 520                                     iova);
 521         if (status & IMSTR_ABORT)
 522                 dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
 523                                     iova);
 524
 525         if (!(status & (IMSTR_PF | IMSTR_TF)))
 526                 return IRQ_NONE;
 527
 528         /*
 529          * Try to handle page faults and translation faults.
 530          *
 531          * TODO: We need to look up the faulty device based on the I/O VA. Use
 532          * the IOMMU device for now.
 533          */
 534         if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
 535                 return IRQ_HANDLED;
 536
 537         dev_err_ratelimited(mmu->dev,
 538                             "Unhandled fault: status 0x%08x iova 0x%lx\n",
 539                             status, iova);
 540
 541         return IRQ_HANDLED;
 542 }
 543
 544 static irqreturn_t ipmmu_irq(int irq, void *dev)
 545 {
 546         struct ipmmu_vmsa_device *mmu = dev;
 547         irqreturn_t status = IRQ_NONE;
 548         unsigned int i;
 549         unsigned long flags;
 550
 551         spin_lock_irqsave(&mmu->lock, flags);
 552
 553         /*
 554          * Check interrupts for all active contexts.
 555          */
 556         for (i = 0; i < mmu->num_ctx; i++) {
 557                 if (!mmu->domains[i])
 558                         continue;
 559                 if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
 560                         status = IRQ_HANDLED;
 561         }
 562
 563         spin_unlock_irqrestore(&mmu->lock, flags);
 564
 565         return status;
 566 }
 567
 568 /* -----------------------------------------------------------------------------
 569  * IOMMU Operations
 570  */
 571
 572 static struct iommu_domain *__ipmmu_domain_alloc(unsigned type)
 573 {
 574         struct ipmmu_vmsa_domain *domain;
 575
 576         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 577         if (!domain)
 578                 return NULL;
 579
 580         mutex_init(&domain->mutex);
 581
 582         return &domain->io_domain;
 583 }
 584
 585 static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
 586 {
 587         struct iommu_domain *io_domain = NULL;
 588
 589         switch (type) {
 590         case IOMMU_DOMAIN_UNMANAGED:
 591                 io_domain = __ipmmu_domain_alloc(type);
 592                 break;
 593
 594         case IOMMU_DOMAIN_DMA:
 595                 io_domain = __ipmmu_domain_alloc(type);
 596                 if (io_domain && iommu_get_dma_cookie(io_domain)) {
 597                         kfree(io_domain);
 598                         io_domain = NULL;
 599                 }
 600                 break;
 601         }
 602
 603         return io_domain;
 604 }
 605
 606 static void ipmmu_domain_free(struct iommu_domain *io_domain)
 607 {
 608         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 609
 610         /*
 611          * Free the domain resources. We assume that all devices have already
 612          * been detached.
 613          */
 614         iommu_put_dma_cookie(io_domain);
 615         ipmmu_domain_destroy_context(domain);
 616         free_io_pgtable_ops(domain->iop);
 617         kfree(domain);
 618 }
 619
 620 static int ipmmu_attach_device(struct iommu_domain *io_domain,
 621                                struct device *dev)
 622 {
 623         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 624         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 625         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 626         unsigned int i;
 627         int ret = 0;
 628
 629         if (!mmu) {
 630                 dev_err(dev, "Cannot attach to IPMMU\n");
 631                 return -ENXIO;
 632         }
 633
 634         mutex_lock(&domain->mutex);
 635
 636         if (!domain->mmu) {
 637                 /* The domain hasn't been used yet, initialize it. */
 638                 domain->mmu = mmu;
 639                 ret = ipmmu_domain_init_context(domain);
 640                 if (ret < 0) {
 641                         dev_err(dev, "Unable to initialize IPMMU context\n");
 642                         domain->mmu = NULL;
 643                 } else {
 644                         dev_info(dev, "Using IPMMU context %u\n",
 645                                  domain->context_id);
 646                 }
 647         } else if (domain->mmu != mmu) {
 648                 /*
 649                  * Something is wrong, we can't attach two devices using
 650                  * different IOMMUs to the same domain.
 651                  */
 652                 dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
 653                         dev_name(mmu->dev), dev_name(domain->mmu->dev));
 654                 ret = -EINVAL;
 655         } else
 656                 dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
 657
 658         mutex_unlock(&domain->mutex);
 659
 660         if (ret < 0)
 661                 return ret;
 662
 663         for (i = 0; i < fwspec->num_ids; ++i)
 664                 ipmmu_utlb_enable(domain, fwspec->ids[i]);
 665
 666         return 0;
 667 }
 668
 669 static void ipmmu_detach_device(struct iommu_domain *io_domain,
 670                                 struct device *dev)
 671 {
 672         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 673         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 674         unsigned int i;
 675
 676         for (i = 0; i < fwspec->num_ids; ++i)
 677                 ipmmu_utlb_disable(domain, fwspec->ids[i]);
 678
 679         /*
 680          * TODO: Optimize by disabling the context when no device is attached.
 681          */
 682 }
 683
 684 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 685                      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 686 {
 687         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 688
 689         if (!domain)
 690                 return -ENODEV;
 691
 692         return domain->iop->map(domain->iop, iova, paddr, size, prot);
 693 }
 694
 695 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
 696                           size_t size, struct iommu_iotlb_gather *gather)
 697 {
 698         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 699
 700         return domain->iop->unmap(domain->iop, iova, size, gather);
 701 }
 702
 703 static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
 704 {
 705         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 706
 707         if (domain->mmu)
 708                 ipmmu_tlb_flush_all(domain);
 709 }
 710
 711 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
 712                              struct iommu_iotlb_gather *gather)
 713 {
 714         ipmmu_flush_iotlb_all(io_domain);
 715 }
 716
 717 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 718                                       dma_addr_t iova)
 719 {
 720         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 721
 722         /* TODO: Is locking needed ? */
 723
 724         return domain->iop->iova_to_phys(domain->iop, iova);
 725 }
 726
 727 static int ipmmu_init_platform_device(struct device *dev,
 728                                       struct of_phandle_args *args)
 729 {
 730         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 731         struct platform_device *ipmmu_pdev;
 732
 733         ipmmu_pdev = of_find_device_by_node(args->np);
 734         if (!ipmmu_pdev)
 735                 return -ENODEV;
 736
 737         fwspec->iommu_priv = platform_get_drvdata(ipmmu_pdev);
 738
 739         return 0;
 740 }
 741
 742 static const struct soc_device_attribute soc_rcar_gen3[] = {
 743         { .soc_id = "r8a774a1", },
 744         { .soc_id = "r8a774b1", },
 745         { .soc_id = "r8a774c0", },
 746         { .soc_id = "r8a7795", },
 747         { .soc_id = "r8a7796", },
 748         { .soc_id = "r8a77965", },
 749         { .soc_id = "r8a77970", },
 750         { .soc_id = "r8a77990", },
 751         { .soc_id = "r8a77995", },
 752         { /* sentinel */ }
 753 };
 754
 755 static const struct soc_device_attribute soc_rcar_gen3_whitelist[] = {
 756         { .soc_id = "r8a774b1", },
 757         { .soc_id = "r8a774c0", },
 758         { .soc_id = "r8a7795", .revision = "ES3.*" },
 759         { .soc_id = "r8a77965", },
 760         { .soc_id = "r8a77990", },
 761         { .soc_id = "r8a77995", },
 762         { /* sentinel */ }
 763 };
 764
 765 static const char * const rcar_gen3_slave_whitelist[] = {
 766 };
 767
 768 static bool ipmmu_slave_whitelist(struct device *dev)
 769 {
 770         unsigned int i;
 771
 772         /*
 773          * For R-Car Gen3 use a white list to opt-in slave devices.
 774          * For Other SoCs, this returns true anyway.
 775          */
 776         if (!soc_device_match(soc_rcar_gen3))
 777                 return true;
 778
 779         /* Check whether this R-Car Gen3 can use the IPMMU correctly or not */
 780         if (!soc_device_match(soc_rcar_gen3_whitelist))
 781                 return false;
 782
 783         /* Check whether this slave device can work with the IPMMU */
 784         for (i = 0; i < ARRAY_SIZE(rcar_gen3_slave_whitelist); i++) {
 785                 if (!strcmp(dev_name(dev), rcar_gen3_slave_whitelist[i]))
 786                         return true;
 787         }
 788
 789         /* Otherwise, do not allow use of IPMMU */
 790         return false;
 791 }
 792
 793 static int ipmmu_of_xlate(struct device *dev,
 794                           struct of_phandle_args *spec)
 795 {
 796         if (!ipmmu_slave_whitelist(dev))
 797                 return -ENODEV;
 798
 799         iommu_fwspec_add_ids(dev, spec->args, 1);
 800
 801         /* Initialize once - xlate() will call multiple times */
 802         if (to_ipmmu(dev))
 803                 return 0;
 804
 805         return ipmmu_init_platform_device(dev, spec);
 806 }
 807
 808 static int ipmmu_init_arm_mapping(struct device *dev)
 809 {
 810         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 811         struct iommu_group *group;
 812         int ret;
 813
 814         /* Create a device group and add the device to it. */
 815         group = iommu_group_alloc();
 816         if (IS_ERR(group)) {
 817                 dev_err(dev, "Failed to allocate IOMMU group\n");
 818                 return PTR_ERR(group);
 819         }
 820
 821         ret = iommu_group_add_device(group, dev);
 822         iommu_group_put(group);
 823
 824         if (ret < 0) {
 825                 dev_err(dev, "Failed to add device to IPMMU group\n");
 826                 return ret;
 827         }
 828
 829         /*
 830          * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 831          * VAs. This will allocate a corresponding IOMMU domain.
 832          *
 833          * TODO:
 834          * - Create one mapping per context (TLB).
 835          * - Make the mapping size configurable ? We currently use a 2GB mapping
 836          *   at a 1GB offset to ensure that NULL VAs will fault.
 837          */
 838         if (!mmu->mapping) {
 839                 struct dma_iommu_mapping *mapping;
 840
 841                 mapping = arm_iommu_create_mapping(&platform_bus_type,
 842                                                    SZ_1G, SZ_2G);
 843                 if (IS_ERR(mapping)) {
 844                         dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 845                         ret = PTR_ERR(mapping);
 846                         goto error;
 847                 }
 848
 849                 mmu->mapping = mapping;
 850         }
 851
 852         /* Attach the ARM VA mapping to the device. */
 853         ret = arm_iommu_attach_device(dev, mmu->mapping);
 854         if (ret < 0) {
 855                 dev_err(dev, "Failed to attach device to VA mapping\n");
 856                 goto error;
 857         }
 858
 859         return 0;
 860
 861 error:
 862         iommu_group_remove_device(dev);
 863         if (mmu->mapping)
 864                 arm_iommu_release_mapping(mmu->mapping);
 865
 866         return ret;
 867 }
 868
 869 static int ipmmu_add_device(struct device *dev)
 870 {
 871         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 872         struct iommu_group *group;
 873         int ret;
 874
 875         /*
 876          * Only let through devices that have been verified in xlate()
 877          */
 878         if (!mmu)
 879                 return -ENODEV;
 880
 881         if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)) {
 882                 ret = ipmmu_init_arm_mapping(dev);
 883                 if (ret)
 884                         return ret;
 885         } else {
 886                 group = iommu_group_get_for_dev(dev);
 887                 if (IS_ERR(group))
 888                         return PTR_ERR(group);
 889
 890                 iommu_group_put(group);
 891         }
 892
 893         iommu_device_link(&mmu->iommu, dev);
 894         return 0;
 895 }
 896
 897 static void ipmmu_remove_device(struct device *dev)
 898 {
 899         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 900
 901         iommu_device_unlink(&mmu->iommu, dev);
 902         arm_iommu_detach_device(dev);
 903         iommu_group_remove_device(dev);
 904 }
 905
 906 static struct iommu_group *ipmmu_find_group(struct device *dev)
 907 {
 908         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 909         struct iommu_group *group;
 910
 911         if (mmu->group)
 912                 return iommu_group_ref_get(mmu->group);
 913
 914         group = iommu_group_alloc();
 915         if (!IS_ERR(group))
 916                 mmu->group = group;
 917
 918         return group;
 919 }
 920
 921 static const struct iommu_ops ipmmu_ops = {
 922         .domain_alloc = ipmmu_domain_alloc,
 923         .domain_free = ipmmu_domain_free,
 924         .attach_dev = ipmmu_attach_device,
 925         .detach_dev = ipmmu_detach_device,
 926         .map = ipmmu_map,
 927         .unmap = ipmmu_unmap,
 928         .flush_iotlb_all = ipmmu_flush_iotlb_all,
 929         .iotlb_sync = ipmmu_iotlb_sync,
 930         .iova_to_phys = ipmmu_iova_to_phys,
 931         .add_device = ipmmu_add_device,
 932         .remove_device = ipmmu_remove_device,
 933         .device_group = ipmmu_find_group,
 934         .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 935         .of_xlate = ipmmu_of_xlate,
 936 };
 937
 938 /* -----------------------------------------------------------------------------
 939  * Probe/remove and init
 940  */
 941
 942 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 943 {
 944         unsigned int i;
 945
 946         /* Disable all contexts. */
 947         for (i = 0; i < mmu->num_ctx; ++i)
 948                 ipmmu_ctx_write(mmu, i, IMCTR, 0);
 949 }
 950
 951 static const struct ipmmu_features ipmmu_features_default = {
 952         .use_ns_alias_offset = true,
 953         .has_cache_leaf_nodes = false,
 954         .number_of_contexts = 1, /* software only tested with one context */
 955         .num_utlbs = 32,
 956         .setup_imbuscr = true,
 957         .twobit_imttbcr_sl0 = false,
 958         .reserved_context = false,
 959         .cache_snoop = true,
 960         .ctx_offset_base = 0,
 961         .ctx_offset_stride = 0x40,
 962         .utlb_offset_base = 0,
 963 };
 964
 965 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 966         .use_ns_alias_offset = false,
 967         .has_cache_leaf_nodes = true,
 968         .number_of_contexts = 8,
 969         .num_utlbs = 48,
 970         .setup_imbuscr = false,
 971         .twobit_imttbcr_sl0 = true,
 972         .reserved_context = true,
 973         .cache_snoop = false,
 974         .ctx_offset_base = 0,
 975         .ctx_offset_stride = 0x40,
 976         .utlb_offset_base = 0,
 977 };
 978
 979 static const struct of_device_id ipmmu_of_ids[] = {
 980         {
 981                 .compatible = "renesas,ipmmu-vmsa",
 982                 .data = &ipmmu_features_default,
 983         }, {
 984                 .compatible = "renesas,ipmmu-r8a774a1",
 985                 .data = &ipmmu_features_rcar_gen3,
 986         }, {
 987                 .compatible = "renesas,ipmmu-r8a774b1",
 988                 .data = &ipmmu_features_rcar_gen3,
 989         }, {
 990                 .compatible = "renesas,ipmmu-r8a774c0",
 991                 .data = &ipmmu_features_rcar_gen3,
 992         }, {
 993                 .compatible = "renesas,ipmmu-r8a7795",
 994                 .data = &ipmmu_features_rcar_gen3,
 995         }, {
 996                 .compatible = "renesas,ipmmu-r8a7796",
 997                 .data = &ipmmu_features_rcar_gen3,
 998         }, {
 999                 .compatible = "renesas,ipmmu-r8a77965",
1000                 .data = &ipmmu_features_rcar_gen3,
1001         }, {
1002                 .compatible = "renesas,ipmmu-r8a77970",
1003                 .data = &ipmmu_features_rcar_gen3,
1004         }, {
1005                 .compatible = "renesas,ipmmu-r8a77990",
1006                 .data = &ipmmu_features_rcar_gen3,
1007         }, {
1008                 .compatible = "renesas,ipmmu-r8a77995",
1009                 .data = &ipmmu_features_rcar_gen3,
1010         }, {
1011                 /* Terminator */
1012         },
1013 };
1014
1015 static int ipmmu_probe(struct platform_device *pdev)
1016 {
1017         struct ipmmu_vmsa_device *mmu;
1018         struct resource *res;
1019         int irq;
1020         int ret;
1021
1022         mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
1023         if (!mmu) {
1024                 dev_err(&pdev->dev, "cannot allocate device data\n");
1025                 return -ENOMEM;
1026         }
1027
1028         mmu->dev = &pdev->dev;
1029         spin_lock_init(&mmu->lock);
1030         bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
1031         mmu->features = of_device_get_match_data(&pdev->dev);
1032         memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs);
1033         dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
1034
1035         /* Map I/O memory and request IRQ. */
1036         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1037         mmu->base = devm_ioremap_resource(&pdev->dev, res);
1038         if (IS_ERR(mmu->base))
1039                 return PTR_ERR(mmu->base);
1040
1041         /*
1042          * The IPMMU has two register banks, for secure and non-secure modes.
1043          * The bank mapped at the beginning of the IPMMU address space
1044          * corresponds to the running mode of the CPU. When running in secure
1045          * mode the non-secure register bank is also available at an offset.
1046          *
1047          * Secure mode operation isn't clearly documented and is thus currently
1048          * not implemented in the driver. Furthermore, preliminary tests of
1049          * non-secure operation with the main register bank were not successful.
1050          * Offset the registers base unconditionally to point to the non-secure
1051          * alias space for now.
1052          */
1053         if (mmu->features->use_ns_alias_offset)
1054                 mmu->base += IM_NS_ALIAS_OFFSET;
1055
1056         mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1057
1058         /*
1059          * Determine if this IPMMU instance is a root device by checking for
1060          * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1061          */
1062         if (!mmu->features->has_cache_leaf_nodes ||
1063             !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
1064                 mmu->root = mmu;
1065         else
1066                 mmu->root = ipmmu_find_root();
1067
1068         /*
1069          * Wait until the root device has been registered for sure.
1070          */
1071         if (!mmu->root)
1072                 return -EPROBE_DEFER;
1073
1074         /* Root devices have mandatory IRQs */
1075         if (ipmmu_is_root(mmu)) {
1076                 irq = platform_get_irq(pdev, 0);
1077                 if (irq < 0)
1078                         return irq;
1079
1080                 ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1081                                        dev_name(&pdev->dev), mmu);
1082                 if (ret < 0) {
1083                         dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1084                         return ret;
1085                 }
1086
1087                 ipmmu_device_reset(mmu);
1088
1089                 if (mmu->features->reserved_context) {
1090                         dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1091                         set_bit(0, mmu->ctx);
1092                 }
1093         }
1094
1095         /*
1096          * Register the IPMMU to the IOMMU subsystem in the following cases:
1097          * - R-Car Gen2 IPMMU (all devices registered)
1098          * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1099          */
1100         if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1101                 ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1102                                              dev_name(&pdev->dev));
1103                 if (ret)
1104                         return ret;
1105
1106                 iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
1107                 iommu_device_set_fwnode(&mmu->iommu,
1108                                         &pdev->dev.of_node->fwnode);
1109
1110                 ret = iommu_device_register(&mmu->iommu);
1111                 if (ret)
1112                         return ret;
1113
1114 #if defined(CONFIG_IOMMU_DMA)
1115                 if (!iommu_present(&platform_bus_type))
1116                         bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1117 #endif
1118         }
1119
1120         /*
1121          * We can't create the ARM mapping here as it requires the bus to have
1122          * an IOMMU, which only happens when bus_set_iommu() is called in
1123          * ipmmu_init() after the probe function returns.
1124          */
1125
1126         platform_set_drvdata(pdev, mmu);
1127
1128         return 0;
1129 }
1130
1131 static int ipmmu_remove(struct platform_device *pdev)
1132 {
1133         struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1134
1135         iommu_device_sysfs_remove(&mmu->iommu);
1136         iommu_device_unregister(&mmu->iommu);
1137
1138         arm_iommu_release_mapping(mmu->mapping);
1139
1140         ipmmu_device_reset(mmu);
1141
1142         return 0;
1143 }
1144
1145 #ifdef CONFIG_PM_SLEEP
1146 static int ipmmu_resume_noirq(struct device *dev)
1147 {
1148         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1149         unsigned int i;
1150
1151         /* Reset root MMU and restore contexts */
1152         if (ipmmu_is_root(mmu)) {
1153                 ipmmu_device_reset(mmu);
1154
1155                 for (i = 0; i < mmu->num_ctx; i++) {
1156                         if (!mmu->domains[i])
1157                                 continue;
1158
1159                         ipmmu_domain_setup_context(mmu->domains[i]);
1160                 }
1161         }
1162
1163         /* Re-enable active micro-TLBs */
1164         for (i = 0; i < mmu->features->num_utlbs; i++) {
1165                 if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1166                         continue;
1167
1168                 ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1169         }
1170
1171         return 0;
1172 }
1173
1174 static const struct dev_pm_ops ipmmu_pm  = {
1175         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1176 };
1177 #define DEV_PM_OPS      &ipmmu_pm
1178 #else
1179 #define DEV_PM_OPS      NULL
1180 #endif /* CONFIG_PM_SLEEP */
1181
1182 static struct platform_driver ipmmu_driver = {
1183         .driver = {
1184                 .name = "ipmmu-vmsa",
1185                 .of_match_table = of_match_ptr(ipmmu_of_ids),
1186                 .pm = DEV_PM_OPS,
1187         },
1188         .probe = ipmmu_probe,
1189         .remove = ipmmu_remove,
1190 };
1191
1192 static int __init ipmmu_init(void)
1193 {
1194         struct device_node *np;
1195         static bool setup_done;
1196         int ret;
1197
1198         if (setup_done)
1199                 return 0;
1200
1201         np = of_find_matching_node(NULL, ipmmu_of_ids);
1202         if (!np)
1203                 return 0;
1204
1205         of_node_put(np);
1206
1207         ret = platform_driver_register(&ipmmu_driver);
1208         if (ret < 0)
1209                 return ret;
1210
1211 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
1212         if (!iommu_present(&platform_bus_type))
1213                 bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1214 #endif
1215
1216         setup_done = true;
1217         return 0;
1218 }
1219 subsys_initcall(ipmmu_init);