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-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 #else
  32 #define arm_iommu_create_mapping(...)   NULL
  33 #define arm_iommu_attach_device(...)    -ENODEV
  34 #define arm_iommu_release_mapping(...)  do {} while (0)
  35 #define arm_iommu_detach_device(...)    do {} while (0)
  36 #endif
  37
  38 #define IPMMU_CTX_MAX           8U
  39 #define IPMMU_CTX_INVALID       -1
  40
  41 #define IPMMU_UTLB_MAX          48U
  42
  43 struct ipmmu_features {
  44         bool use_ns_alias_offset;
  45         bool has_cache_leaf_nodes;
  46         unsigned int number_of_contexts;
  47         unsigned int num_utlbs;
  48         bool setup_imbuscr;
  49         bool twobit_imttbcr_sl0;
  50         bool reserved_context;
  51         bool cache_snoop;
  52         unsigned int ctx_offset_base;
  53         unsigned int ctx_offset_stride;
  54         unsigned int utlb_offset_base;
  55 };
  56
  57 struct ipmmu_vmsa_device {
  58         struct device *dev;
  59         void __iomem *base;
  60         struct iommu_device iommu;
  61         struct ipmmu_vmsa_device *root;
  62         const struct ipmmu_features *features;
  63         unsigned int num_ctx;
  64         spinlock_t lock;                        /* Protects ctx and domains[] */
  65         DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
  66         struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
  67         s8 utlb_ctx[IPMMU_UTLB_MAX];
  68
  69         struct iommu_group *group;
  70         struct dma_iommu_mapping *mapping;
  71 };
  72
  73 struct ipmmu_vmsa_domain {
  74         struct ipmmu_vmsa_device *mmu;
  75         struct iommu_domain io_domain;
  76
  77         struct io_pgtable_cfg cfg;
  78         struct io_pgtable_ops *iop;
  79
  80         unsigned int context_id;
  81         struct mutex mutex;                     /* Protects mappings */
  82 };
  83
  84 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
  85 {
  86         return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
  87 }
  88
  89 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
  90 {
  91         return dev_iommu_priv_get(dev);
  92 }
  93
  94 #define TLB_LOOP_TIMEOUT                100     /* 100us */
  95
  96 /* -----------------------------------------------------------------------------
  97  * Registers Definition
  98  */
  99
 100 #define IM_NS_ALIAS_OFFSET              0x800
 101
 102 /* MMU "context" registers */
 103 #define IMCTR                           0x0000          /* R-Car Gen2/3 */
 104 #define IMCTR_INTEN                     (1 << 2)        /* R-Car Gen2/3 */
 105 #define IMCTR_FLUSH                     (1 << 1)        /* R-Car Gen2/3 */
 106 #define IMCTR_MMUEN                     (1 << 0)        /* R-Car Gen2/3 */
 107
 108 #define IMTTBCR                         0x0008          /* R-Car Gen2/3 */
 109 #define IMTTBCR_EAE                     (1 << 31)       /* R-Car Gen2/3 */
 110 #define IMTTBCR_SH0_INNER_SHAREABLE     (3 << 12)       /* R-Car Gen2 only */
 111 #define IMTTBCR_ORGN0_WB_WA             (1 << 10)       /* R-Car Gen2 only */
 112 #define IMTTBCR_IRGN0_WB_WA             (1 << 8)        /* R-Car Gen2 only */
 113 #define IMTTBCR_SL0_TWOBIT_LVL_1        (2 << 6)        /* R-Car Gen3 only */
 114 #define IMTTBCR_SL0_LVL_1               (1 << 4)        /* R-Car Gen2 only */
 115
 116 #define IMBUSCR                         0x000c          /* R-Car Gen2 only */
 117 #define IMBUSCR_DVM                     (1 << 2)        /* R-Car Gen2 only */
 118 #define IMBUSCR_BUSSEL_MASK             (3 << 0)        /* R-Car Gen2 only */
 119
 120 #define IMTTLBR0                        0x0010          /* R-Car Gen2/3 */
 121 #define IMTTUBR0                        0x0014          /* R-Car Gen2/3 */
 122
 123 #define IMSTR                           0x0020          /* R-Car Gen2/3 */
 124 #define IMSTR_MHIT                      (1 << 4)        /* R-Car Gen2/3 */
 125 #define IMSTR_ABORT                     (1 << 2)        /* R-Car Gen2/3 */
 126 #define IMSTR_PF                        (1 << 1)        /* R-Car Gen2/3 */
 127 #define IMSTR_TF                        (1 << 0)        /* R-Car Gen2/3 */
 128
 129 #define IMMAIR0                         0x0028          /* R-Car Gen2/3 */
 130
 131 #define IMELAR                          0x0030          /* R-Car Gen2/3, IMEAR on R-Car Gen2 */
 132 #define IMEUAR                          0x0034          /* R-Car Gen3 only */
 133
 134 /* uTLB registers */
 135 #define IMUCTR(n)                       ((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
 136 #define IMUCTR0(n)                      (0x0300 + ((n) * 16))           /* R-Car Gen2/3 */
 137 #define IMUCTR32(n)                     (0x0600 + (((n) - 32) * 16))    /* R-Car Gen3 only */
 138 #define IMUCTR_TTSEL_MMU(n)             ((n) << 4)      /* R-Car Gen2/3 */
 139 #define IMUCTR_FLUSH                    (1 << 1)        /* R-Car Gen2/3 */
 140 #define IMUCTR_MMUEN                    (1 << 0)        /* R-Car Gen2/3 */
 141
 142 #define IMUASID(n)                      ((n) < 32 ? IMUASID0(n) : IMUASID32(n))
 143 #define IMUASID0(n)                     (0x0308 + ((n) * 16))           /* R-Car Gen2/3 */
 144 #define IMUASID32(n)                    (0x0608 + (((n) - 32) * 16))    /* R-Car Gen3 only */
 145
 146 /* -----------------------------------------------------------------------------
 147  * Root device handling
 148  */
 149
 150 static struct platform_driver ipmmu_driver;
 151
 152 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
 153 {
 154         return mmu->root == mmu;
 155 }
 156
 157 static int __ipmmu_check_device(struct device *dev, void *data)
 158 {
 159         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
 160         struct ipmmu_vmsa_device **rootp = data;
 161
 162         if (ipmmu_is_root(mmu))
 163                 *rootp = mmu;
 164
 165         return 0;
 166 }
 167
 168 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
 169 {
 170         struct ipmmu_vmsa_device *root = NULL;
 171
 172         return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
 173                                       __ipmmu_check_device) == 0 ? root : NULL;
 174 }
 175
 176 /* -----------------------------------------------------------------------------
 177  * Read/Write Access
 178  */
 179
 180 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
 181 {
 182         return ioread32(mmu->base + offset);
 183 }
 184
 185 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 186                         u32 data)
 187 {
 188         iowrite32(data, mmu->base + offset);
 189 }
 190
 191 static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
 192                                   unsigned int context_id, unsigned int reg)
 193 {
 194         return mmu->features->ctx_offset_base +
 195                context_id * mmu->features->ctx_offset_stride + reg;
 196 }
 197
 198 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
 199                           unsigned int context_id, unsigned int reg)
 200 {
 201         return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
 202 }
 203
 204 static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
 205                             unsigned int context_id, unsigned int reg, u32 data)
 206 {
 207         ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
 208 }
 209
 210 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 211                                unsigned int reg)
 212 {
 213         return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
 214 }
 215
 216 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 217                                  unsigned int reg, u32 data)
 218 {
 219         ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 220 }
 221
 222 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 223                                 unsigned int reg, u32 data)
 224 {
 225         if (domain->mmu != domain->mmu->root)
 226                 ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
 227
 228         ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
 229 }
 230
 231 static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
 232 {
 233         return mmu->features->utlb_offset_base + reg;
 234 }
 235
 236 static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
 237                                 unsigned int utlb, u32 data)
 238 {
 239         ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
 240 }
 241
 242 static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
 243                                unsigned int utlb, u32 data)
 244 {
 245         ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
 246 }
 247
 248 /* -----------------------------------------------------------------------------
 249  * TLB and microTLB Management
 250  */
 251
 252 /* Wait for any pending TLB invalidations to complete */
 253 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
 254 {
 255         unsigned int count = 0;
 256
 257         while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
 258                 cpu_relax();
 259                 if (++count == TLB_LOOP_TIMEOUT) {
 260                         dev_err_ratelimited(domain->mmu->dev,
 261                         "TLB sync timed out -- MMU may be deadlocked\n");
 262                         return;
 263                 }
 264                 udelay(1);
 265         }
 266 }
 267
 268 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
 269 {
 270         u32 reg;
 271
 272         reg = ipmmu_ctx_read_root(domain, IMCTR);
 273         reg |= IMCTR_FLUSH;
 274         ipmmu_ctx_write_all(domain, IMCTR, reg);
 275
 276         ipmmu_tlb_sync(domain);
 277 }
 278
 279 /*
 280  * Enable MMU translation for the microTLB.
 281  */
 282 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 283                               unsigned int utlb)
 284 {
 285         struct ipmmu_vmsa_device *mmu = domain->mmu;
 286
 287         /*
 288          * TODO: Reference-count the microTLB as several bus masters can be
 289          * connected to the same microTLB.
 290          */
 291
 292         /* TODO: What should we set the ASID to ? */
 293         ipmmu_imuasid_write(mmu, utlb, 0);
 294         /* TODO: Do we need to flush the microTLB ? */
 295         ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
 296                                       IMUCTR_FLUSH | IMUCTR_MMUEN);
 297         mmu->utlb_ctx[utlb] = domain->context_id;
 298 }
 299
 300 /*
 301  * Disable MMU translation for the microTLB.
 302  */
 303 static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 304                                unsigned int utlb)
 305 {
 306         struct ipmmu_vmsa_device *mmu = domain->mmu;
 307
 308         ipmmu_imuctr_write(mmu, utlb, 0);
 309         mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
 310 }
 311
 312 static void ipmmu_tlb_flush_all(void *cookie)
 313 {
 314         struct ipmmu_vmsa_domain *domain = cookie;
 315
 316         ipmmu_tlb_invalidate(domain);
 317 }
 318
 319 static void ipmmu_tlb_flush(unsigned long iova, size_t size,
 320                                 size_t granule, void *cookie)
 321 {
 322         ipmmu_tlb_flush_all(cookie);
 323 }
 324
 325 static const struct iommu_flush_ops ipmmu_flush_ops = {
 326         .tlb_flush_all = ipmmu_tlb_flush_all,
 327         .tlb_flush_walk = ipmmu_tlb_flush,
 328 };
 329
 330 /* -----------------------------------------------------------------------------
 331  * Domain/Context Management
 332  */
 333
 334 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
 335                                          struct ipmmu_vmsa_domain *domain)
 336 {
 337         unsigned long flags;
 338         int ret;
 339
 340         spin_lock_irqsave(&mmu->lock, flags);
 341
 342         ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
 343         if (ret != mmu->num_ctx) {
 344                 mmu->domains[ret] = domain;
 345                 set_bit(ret, mmu->ctx);
 346         } else
 347                 ret = -EBUSY;
 348
 349         spin_unlock_irqrestore(&mmu->lock, flags);
 350
 351         return ret;
 352 }
 353
 354 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 355                                       unsigned int context_id)
 356 {
 357         unsigned long flags;
 358
 359         spin_lock_irqsave(&mmu->lock, flags);
 360
 361         clear_bit(context_id, mmu->ctx);
 362         mmu->domains[context_id] = NULL;
 363
 364         spin_unlock_irqrestore(&mmu->lock, flags);
 365 }
 366
 367 static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
 368 {
 369         u64 ttbr;
 370         u32 tmp;
 371
 372         /* TTBR0 */
 373         ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
 374         ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
 375         ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 376
 377         /*
 378          * TTBCR
 379          * We use long descriptors and allocate the whole 32-bit VA space to
 380          * TTBR0.
 381          */
 382         if (domain->mmu->features->twobit_imttbcr_sl0)
 383                 tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
 384         else
 385                 tmp = IMTTBCR_SL0_LVL_1;
 386
 387         if (domain->mmu->features->cache_snoop)
 388                 tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
 389                        IMTTBCR_IRGN0_WB_WA;
 390
 391         ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
 392
 393         /* MAIR0 */
 394         ipmmu_ctx_write_root(domain, IMMAIR0,
 395                              domain->cfg.arm_lpae_s1_cfg.mair);
 396
 397         /* IMBUSCR */
 398         if (domain->mmu->features->setup_imbuscr)
 399                 ipmmu_ctx_write_root(domain, IMBUSCR,
 400                                      ipmmu_ctx_read_root(domain, IMBUSCR) &
 401                                      ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 402
 403         /*
 404          * IMSTR
 405          * Clear all interrupt flags.
 406          */
 407         ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
 408
 409         /*
 410          * IMCTR
 411          * Enable the MMU and interrupt generation. The long-descriptor
 412          * translation table format doesn't use TEX remapping. Don't enable AF
 413          * software management as we have no use for it. Flush the TLB as
 414          * required when modifying the context registers.
 415          */
 416         ipmmu_ctx_write_all(domain, IMCTR,
 417                             IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 418 }
 419
 420 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 421 {
 422         int ret;
 423
 424         /*
 425          * Allocate the page table operations.
 426          *
 427          * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
 428          * access, Long-descriptor format" that the NStable bit being set in a
 429          * table descriptor will result in the NStable and NS bits of all child
 430          * entries being ignored and considered as being set. The IPMMU seems
 431          * not to comply with this, as it generates a secure access page fault
 432          * if any of the NStable and NS bits isn't set when running in
 433          * non-secure mode.
 434          */
 435         domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
 436         domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
 437         domain->cfg.ias = 32;
 438         domain->cfg.oas = 40;
 439         domain->cfg.tlb = &ipmmu_flush_ops;
 440         domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
 441         domain->io_domain.geometry.force_aperture = true;
 442         /*
 443          * TODO: Add support for coherent walk through CCI with DVM and remove
 444          * cache handling. For now, delegate it to the io-pgtable code.
 445          */
 446         domain->cfg.coherent_walk = false;
 447         domain->cfg.iommu_dev = domain->mmu->root->dev;
 448
 449         /*
 450          * Find an unused context.
 451          */
 452         ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
 453         if (ret < 0)
 454                 return ret;
 455
 456         domain->context_id = ret;
 457
 458         domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 459                                            domain);
 460         if (!domain->iop) {
 461                 ipmmu_domain_free_context(domain->mmu->root,
 462                                           domain->context_id);
 463                 return -EINVAL;
 464         }
 465
 466         ipmmu_domain_setup_context(domain);
 467         return 0;
 468 }
 469
 470 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 471 {
 472         if (!domain->mmu)
 473                 return;
 474
 475         /*
 476          * Disable the context. Flush the TLB as required when modifying the
 477          * context registers.
 478          *
 479          * TODO: Is TLB flush really needed ?
 480          */
 481         ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
 482         ipmmu_tlb_sync(domain);
 483         ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
 484 }
 485
 486 /* -----------------------------------------------------------------------------
 487  * Fault Handling
 488  */
 489
 490 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 491 {
 492         const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
 493         struct ipmmu_vmsa_device *mmu = domain->mmu;
 494         unsigned long iova;
 495         u32 status;
 496
 497         status = ipmmu_ctx_read_root(domain, IMSTR);
 498         if (!(status & err_mask))
 499                 return IRQ_NONE;
 500
 501         iova = ipmmu_ctx_read_root(domain, IMELAR);
 502         if (IS_ENABLED(CONFIG_64BIT))
 503                 iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
 504
 505         /*
 506          * Clear the error status flags. Unlike traditional interrupt flag
 507          * registers that must be cleared by writing 1, this status register
 508          * seems to require 0. The error address register must be read before,
 509          * otherwise its value will be 0.
 510          */
 511         ipmmu_ctx_write_root(domain, IMSTR, 0);
 512
 513         /* Log fatal errors. */
 514         if (status & IMSTR_MHIT)
 515                 dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
 516                                     iova);
 517         if (status & IMSTR_ABORT)
 518                 dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
 519                                     iova);
 520
 521         if (!(status & (IMSTR_PF | IMSTR_TF)))
 522                 return IRQ_NONE;
 523
 524         /*
 525          * Try to handle page faults and translation faults.
 526          *
 527          * TODO: We need to look up the faulty device based on the I/O VA. Use
 528          * the IOMMU device for now.
 529          */
 530         if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
 531                 return IRQ_HANDLED;
 532
 533         dev_err_ratelimited(mmu->dev,
 534                             "Unhandled fault: status 0x%08x iova 0x%lx\n",
 535                             status, iova);
 536
 537         return IRQ_HANDLED;
 538 }
 539
 540 static irqreturn_t ipmmu_irq(int irq, void *dev)
 541 {
 542         struct ipmmu_vmsa_device *mmu = dev;
 543         irqreturn_t status = IRQ_NONE;
 544         unsigned int i;
 545         unsigned long flags;
 546
 547         spin_lock_irqsave(&mmu->lock, flags);
 548
 549         /*
 550          * Check interrupts for all active contexts.
 551          */
 552         for (i = 0; i < mmu->num_ctx; i++) {
 553                 if (!mmu->domains[i])
 554                         continue;
 555                 if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
 556                         status = IRQ_HANDLED;
 557         }
 558
 559         spin_unlock_irqrestore(&mmu->lock, flags);
 560
 561         return status;
 562 }
 563
 564 /* -----------------------------------------------------------------------------
 565  * IOMMU Operations
 566  */
 567
 568 static struct iommu_domain *__ipmmu_domain_alloc(unsigned type)
 569 {
 570         struct ipmmu_vmsa_domain *domain;
 571
 572         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 573         if (!domain)
 574                 return NULL;
 575
 576         mutex_init(&domain->mutex);
 577
 578         return &domain->io_domain;
 579 }
 580
 581 static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
 582 {
 583         struct iommu_domain *io_domain = NULL;
 584
 585         switch (type) {
 586         case IOMMU_DOMAIN_UNMANAGED:
 587                 io_domain = __ipmmu_domain_alloc(type);
 588                 break;
 589
 590         case IOMMU_DOMAIN_DMA:
 591                 io_domain = __ipmmu_domain_alloc(type);
 592                 if (io_domain && iommu_get_dma_cookie(io_domain)) {
 593                         kfree(io_domain);
 594                         io_domain = NULL;
 595                 }
 596                 break;
 597         }
 598
 599         return io_domain;
 600 }
 601
 602 static void ipmmu_domain_free(struct iommu_domain *io_domain)
 603 {
 604         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 605
 606         /*
 607          * Free the domain resources. We assume that all devices have already
 608          * been detached.
 609          */
 610         iommu_put_dma_cookie(io_domain);
 611         ipmmu_domain_destroy_context(domain);
 612         free_io_pgtable_ops(domain->iop);
 613         kfree(domain);
 614 }
 615
 616 static int ipmmu_attach_device(struct iommu_domain *io_domain,
 617                                struct device *dev)
 618 {
 619         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 620         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 621         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 622         unsigned int i;
 623         int ret = 0;
 624
 625         if (!mmu) {
 626                 dev_err(dev, "Cannot attach to IPMMU\n");
 627                 return -ENXIO;
 628         }
 629
 630         mutex_lock(&domain->mutex);
 631
 632         if (!domain->mmu) {
 633                 /* The domain hasn't been used yet, initialize it. */
 634                 domain->mmu = mmu;
 635                 ret = ipmmu_domain_init_context(domain);
 636                 if (ret < 0) {
 637                         dev_err(dev, "Unable to initialize IPMMU context\n");
 638                         domain->mmu = NULL;
 639                 } else {
 640                         dev_info(dev, "Using IPMMU context %u\n",
 641                                  domain->context_id);
 642                 }
 643         } else if (domain->mmu != mmu) {
 644                 /*
 645                  * Something is wrong, we can't attach two devices using
 646                  * different IOMMUs to the same domain.
 647                  */
 648                 dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
 649                         dev_name(mmu->dev), dev_name(domain->mmu->dev));
 650                 ret = -EINVAL;
 651         } else
 652                 dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
 653
 654         mutex_unlock(&domain->mutex);
 655
 656         if (ret < 0)
 657                 return ret;
 658
 659         for (i = 0; i < fwspec->num_ids; ++i)
 660                 ipmmu_utlb_enable(domain, fwspec->ids[i]);
 661
 662         return 0;
 663 }
 664
 665 static void ipmmu_detach_device(struct iommu_domain *io_domain,
 666                                 struct device *dev)
 667 {
 668         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 669         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 670         unsigned int i;
 671
 672         for (i = 0; i < fwspec->num_ids; ++i)
 673                 ipmmu_utlb_disable(domain, fwspec->ids[i]);
 674
 675         /*
 676          * TODO: Optimize by disabling the context when no device is attached.
 677          */
 678 }
 679
 680 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 681                      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 682 {
 683         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 684
 685         if (!domain)
 686                 return -ENODEV;
 687
 688         return domain->iop->map(domain->iop, iova, paddr, size, prot, gfp);
 689 }
 690
 691 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
 692                           size_t size, struct iommu_iotlb_gather *gather)
 693 {
 694         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 695
 696         return domain->iop->unmap(domain->iop, iova, size, gather);
 697 }
 698
 699 static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
 700 {
 701         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 702
 703         if (domain->mmu)
 704                 ipmmu_tlb_flush_all(domain);
 705 }
 706
 707 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
 708                              struct iommu_iotlb_gather *gather)
 709 {
 710         ipmmu_flush_iotlb_all(io_domain);
 711 }
 712
 713 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 714                                       dma_addr_t iova)
 715 {
 716         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 717
 718         /* TODO: Is locking needed ? */
 719
 720         return domain->iop->iova_to_phys(domain->iop, iova);
 721 }
 722
 723 static int ipmmu_init_platform_device(struct device *dev,
 724                                       struct of_phandle_args *args)
 725 {
 726         struct platform_device *ipmmu_pdev;
 727
 728         ipmmu_pdev = of_find_device_by_node(args->np);
 729         if (!ipmmu_pdev)
 730                 return -ENODEV;
 731
 732         dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
 733
 734         return 0;
 735 }
 736
 737 static const struct soc_device_attribute soc_rcar_gen3[] = {
 738         { .soc_id = "r8a774a1", },
 739         { .soc_id = "r8a774b1", },
 740         { .soc_id = "r8a774c0", },
 741         { .soc_id = "r8a774e1", },
 742         { .soc_id = "r8a7795", },
 743         { .soc_id = "r8a77961", },
 744         { .soc_id = "r8a7796", },
 745         { .soc_id = "r8a77965", },
 746         { .soc_id = "r8a77970", },
 747         { .soc_id = "r8a77990", },
 748         { .soc_id = "r8a77995", },
 749         { /* sentinel */ }
 750 };
 751
 752 static const struct soc_device_attribute soc_rcar_gen3_whitelist[] = {
 753         { .soc_id = "r8a774b1", },
 754         { .soc_id = "r8a774c0", },
 755         { .soc_id = "r8a774e1", },
 756         { .soc_id = "r8a7795", .revision = "ES3.*" },
 757         { .soc_id = "r8a77961", },
 758         { .soc_id = "r8a77965", },
 759         { .soc_id = "r8a77990", },
 760         { .soc_id = "r8a77995", },
 761         { /* sentinel */ }
 762 };
 763
 764 static const char * const rcar_gen3_slave_whitelist[] = {
 765 };
 766
 767 static bool ipmmu_slave_whitelist(struct device *dev)
 768 {
 769         unsigned int i;
 770
 771         /*
 772          * For R-Car Gen3 use a white list to opt-in slave devices.
 773          * For Other SoCs, this returns true anyway.
 774          */
 775         if (!soc_device_match(soc_rcar_gen3))
 776                 return true;
 777
 778         /* Check whether this R-Car Gen3 can use the IPMMU correctly or not */
 779         if (!soc_device_match(soc_rcar_gen3_whitelist))
 780                 return false;
 781
 782         /* Check whether this slave device can work with the IPMMU */
 783         for (i = 0; i < ARRAY_SIZE(rcar_gen3_slave_whitelist); i++) {
 784                 if (!strcmp(dev_name(dev), rcar_gen3_slave_whitelist[i]))
 785                         return true;
 786         }
 787
 788         /* Otherwise, do not allow use of IPMMU */
 789         return false;
 790 }
 791
 792 static int ipmmu_of_xlate(struct device *dev,
 793                           struct of_phandle_args *spec)
 794 {
 795         if (!ipmmu_slave_whitelist(dev))
 796                 return -ENODEV;
 797
 798         iommu_fwspec_add_ids(dev, spec->args, 1);
 799
 800         /* Initialize once - xlate() will call multiple times */
 801         if (to_ipmmu(dev))
 802                 return 0;
 803
 804         return ipmmu_init_platform_device(dev, spec);
 805 }
 806
 807 static int ipmmu_init_arm_mapping(struct device *dev)
 808 {
 809         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 810         int ret;
 811
 812         /*
 813          * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 814          * VAs. This will allocate a corresponding IOMMU domain.
 815          *
 816          * TODO:
 817          * - Create one mapping per context (TLB).
 818          * - Make the mapping size configurable ? We currently use a 2GB mapping
 819          *   at a 1GB offset to ensure that NULL VAs will fault.
 820          */
 821         if (!mmu->mapping) {
 822                 struct dma_iommu_mapping *mapping;
 823
 824                 mapping = arm_iommu_create_mapping(&platform_bus_type,
 825                                                    SZ_1G, SZ_2G);
 826                 if (IS_ERR(mapping)) {
 827                         dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 828                         ret = PTR_ERR(mapping);
 829                         goto error;
 830                 }
 831
 832                 mmu->mapping = mapping;
 833         }
 834
 835         /* Attach the ARM VA mapping to the device. */
 836         ret = arm_iommu_attach_device(dev, mmu->mapping);
 837         if (ret < 0) {
 838                 dev_err(dev, "Failed to attach device to VA mapping\n");
 839                 goto error;
 840         }
 841
 842         return 0;
 843
 844 error:
 845         if (mmu->mapping)
 846                 arm_iommu_release_mapping(mmu->mapping);
 847
 848         return ret;
 849 }
 850
 851 static struct iommu_device *ipmmu_probe_device(struct device *dev)
 852 {
 853         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 854
 855         /*
 856          * Only let through devices that have been verified in xlate()
 857          */
 858         if (!mmu)
 859                 return ERR_PTR(-ENODEV);
 860
 861         return &mmu->iommu;
 862 }
 863
 864 static void ipmmu_probe_finalize(struct device *dev)
 865 {
 866         int ret = 0;
 867
 868         if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
 869                 ret = ipmmu_init_arm_mapping(dev);
 870
 871         if (ret)
 872                 dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
 873 }
 874
 875 static void ipmmu_release_device(struct device *dev)
 876 {
 877         arm_iommu_detach_device(dev);
 878 }
 879
 880 static struct iommu_group *ipmmu_find_group(struct device *dev)
 881 {
 882         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 883         struct iommu_group *group;
 884
 885         if (mmu->group)
 886                 return iommu_group_ref_get(mmu->group);
 887
 888         group = iommu_group_alloc();
 889         if (!IS_ERR(group))
 890                 mmu->group = group;
 891
 892         return group;
 893 }
 894
 895 static const struct iommu_ops ipmmu_ops = {
 896         .domain_alloc = ipmmu_domain_alloc,
 897         .domain_free = ipmmu_domain_free,
 898         .attach_dev = ipmmu_attach_device,
 899         .detach_dev = ipmmu_detach_device,
 900         .map = ipmmu_map,
 901         .unmap = ipmmu_unmap,
 902         .flush_iotlb_all = ipmmu_flush_iotlb_all,
 903         .iotlb_sync = ipmmu_iotlb_sync,
 904         .iova_to_phys = ipmmu_iova_to_phys,
 905         .probe_device = ipmmu_probe_device,
 906         .release_device = ipmmu_release_device,
 907         .probe_finalize = ipmmu_probe_finalize,
 908         .device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
 909                         ? generic_device_group : ipmmu_find_group,
 910         .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 911         .of_xlate = ipmmu_of_xlate,
 912 };
 913
 914 /* -----------------------------------------------------------------------------
 915  * Probe/remove and init
 916  */
 917
 918 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 919 {
 920         unsigned int i;
 921
 922         /* Disable all contexts. */
 923         for (i = 0; i < mmu->num_ctx; ++i)
 924                 ipmmu_ctx_write(mmu, i, IMCTR, 0);
 925 }
 926
 927 static const struct ipmmu_features ipmmu_features_default = {
 928         .use_ns_alias_offset = true,
 929         .has_cache_leaf_nodes = false,
 930         .number_of_contexts = 1, /* software only tested with one context */
 931         .num_utlbs = 32,
 932         .setup_imbuscr = true,
 933         .twobit_imttbcr_sl0 = false,
 934         .reserved_context = false,
 935         .cache_snoop = true,
 936         .ctx_offset_base = 0,
 937         .ctx_offset_stride = 0x40,
 938         .utlb_offset_base = 0,
 939 };
 940
 941 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 942         .use_ns_alias_offset = false,
 943         .has_cache_leaf_nodes = true,
 944         .number_of_contexts = 8,
 945         .num_utlbs = 48,
 946         .setup_imbuscr = false,
 947         .twobit_imttbcr_sl0 = true,
 948         .reserved_context = true,
 949         .cache_snoop = false,
 950         .ctx_offset_base = 0,
 951         .ctx_offset_stride = 0x40,
 952         .utlb_offset_base = 0,
 953 };
 954
 955 static const struct of_device_id ipmmu_of_ids[] = {
 956         {
 957                 .compatible = "renesas,ipmmu-vmsa",
 958                 .data = &ipmmu_features_default,
 959         }, {
 960                 .compatible = "renesas,ipmmu-r8a774a1",
 961                 .data = &ipmmu_features_rcar_gen3,
 962         }, {
 963                 .compatible = "renesas,ipmmu-r8a774b1",
 964                 .data = &ipmmu_features_rcar_gen3,
 965         }, {
 966                 .compatible = "renesas,ipmmu-r8a774c0",
 967                 .data = &ipmmu_features_rcar_gen3,
 968         }, {
 969                 .compatible = "renesas,ipmmu-r8a774e1",
 970                 .data = &ipmmu_features_rcar_gen3,
 971         }, {
 972                 .compatible = "renesas,ipmmu-r8a7795",
 973                 .data = &ipmmu_features_rcar_gen3,
 974         }, {
 975                 .compatible = "renesas,ipmmu-r8a7796",
 976                 .data = &ipmmu_features_rcar_gen3,
 977         }, {
 978                 .compatible = "renesas,ipmmu-r8a77961",
 979                 .data = &ipmmu_features_rcar_gen3,
 980         }, {
 981                 .compatible = "renesas,ipmmu-r8a77965",
 982                 .data = &ipmmu_features_rcar_gen3,
 983         }, {
 984                 .compatible = "renesas,ipmmu-r8a77970",
 985                 .data = &ipmmu_features_rcar_gen3,
 986         }, {
 987                 .compatible = "renesas,ipmmu-r8a77990",
 988                 .data = &ipmmu_features_rcar_gen3,
 989         }, {
 990                 .compatible = "renesas,ipmmu-r8a77995",
 991                 .data = &ipmmu_features_rcar_gen3,
 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         dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
1016
1017         /* Map I/O memory and request IRQ. */
1018         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1019         mmu->base = devm_ioremap_resource(&pdev->dev, res);
1020         if (IS_ERR(mmu->base))
1021                 return PTR_ERR(mmu->base);
1022
1023         /*
1024          * The IPMMU has two register banks, for secure and non-secure modes.
1025          * The bank mapped at the beginning of the IPMMU address space
1026          * corresponds to the running mode of the CPU. When running in secure
1027          * mode the non-secure register bank is also available at an offset.
1028          *
1029          * Secure mode operation isn't clearly documented and is thus currently
1030          * not implemented in the driver. Furthermore, preliminary tests of
1031          * non-secure operation with the main register bank were not successful.
1032          * Offset the registers base unconditionally to point to the non-secure
1033          * alias space for now.
1034          */
1035         if (mmu->features->use_ns_alias_offset)
1036                 mmu->base += IM_NS_ALIAS_OFFSET;
1037
1038         mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1039
1040         /*
1041          * Determine if this IPMMU instance is a root device by checking for
1042          * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1043          */
1044         if (!mmu->features->has_cache_leaf_nodes ||
1045             !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
1046                 mmu->root = mmu;
1047         else
1048                 mmu->root = ipmmu_find_root();
1049
1050         /*
1051          * Wait until the root device has been registered for sure.
1052          */
1053         if (!mmu->root)
1054                 return -EPROBE_DEFER;
1055
1056         /* Root devices have mandatory IRQs */
1057         if (ipmmu_is_root(mmu)) {
1058                 irq = platform_get_irq(pdev, 0);
1059                 if (irq < 0)
1060                         return irq;
1061
1062                 ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1063                                        dev_name(&pdev->dev), mmu);
1064                 if (ret < 0) {
1065                         dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1066                         return ret;
1067                 }
1068
1069                 ipmmu_device_reset(mmu);
1070
1071                 if (mmu->features->reserved_context) {
1072                         dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1073                         set_bit(0, mmu->ctx);
1074                 }
1075         }
1076
1077         /*
1078          * Register the IPMMU to the IOMMU subsystem in the following cases:
1079          * - R-Car Gen2 IPMMU (all devices registered)
1080          * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1081          */
1082         if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1083                 ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1084                                              dev_name(&pdev->dev));
1085                 if (ret)
1086                         return ret;
1087
1088                 iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
1089                 iommu_device_set_fwnode(&mmu->iommu,
1090                                         &pdev->dev.of_node->fwnode);
1091
1092                 ret = iommu_device_register(&mmu->iommu);
1093                 if (ret)
1094                         return ret;
1095
1096 #if defined(CONFIG_IOMMU_DMA)
1097                 if (!iommu_present(&platform_bus_type))
1098                         bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1099 #endif
1100         }
1101
1102         /*
1103          * We can't create the ARM mapping here as it requires the bus to have
1104          * an IOMMU, which only happens when bus_set_iommu() is called in
1105          * ipmmu_init() after the probe function returns.
1106          */
1107
1108         platform_set_drvdata(pdev, mmu);
1109
1110         return 0;
1111 }
1112
1113 static int ipmmu_remove(struct platform_device *pdev)
1114 {
1115         struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1116
1117         iommu_device_sysfs_remove(&mmu->iommu);
1118         iommu_device_unregister(&mmu->iommu);
1119
1120         arm_iommu_release_mapping(mmu->mapping);
1121
1122         ipmmu_device_reset(mmu);
1123
1124         return 0;
1125 }
1126
1127 #ifdef CONFIG_PM_SLEEP
1128 static int ipmmu_resume_noirq(struct device *dev)
1129 {
1130         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1131         unsigned int i;
1132
1133         /* Reset root MMU and restore contexts */
1134         if (ipmmu_is_root(mmu)) {
1135                 ipmmu_device_reset(mmu);
1136
1137                 for (i = 0; i < mmu->num_ctx; i++) {
1138                         if (!mmu->domains[i])
1139                                 continue;
1140
1141                         ipmmu_domain_setup_context(mmu->domains[i]);
1142                 }
1143         }
1144
1145         /* Re-enable active micro-TLBs */
1146         for (i = 0; i < mmu->features->num_utlbs; i++) {
1147                 if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1148                         continue;
1149
1150                 ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1151         }
1152
1153         return 0;
1154 }
1155
1156 static const struct dev_pm_ops ipmmu_pm  = {
1157         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1158 };
1159 #define DEV_PM_OPS      &ipmmu_pm
1160 #else
1161 #define DEV_PM_OPS      NULL
1162 #endif /* CONFIG_PM_SLEEP */
1163
1164 static struct platform_driver ipmmu_driver = {
1165         .driver = {
1166                 .name = "ipmmu-vmsa",
1167                 .of_match_table = of_match_ptr(ipmmu_of_ids),
1168                 .pm = DEV_PM_OPS,
1169         },
1170         .probe = ipmmu_probe,
1171         .remove = ipmmu_remove,
1172 };
1173
1174 static int __init ipmmu_init(void)
1175 {
1176         struct device_node *np;
1177         static bool setup_done;
1178         int ret;
1179
1180         if (setup_done)
1181                 return 0;
1182
1183         np = of_find_matching_node(NULL, ipmmu_of_ids);
1184         if (!np)
1185                 return 0;
1186
1187         of_node_put(np);
1188
1189         ret = platform_driver_register(&ipmmu_driver);
1190         if (ret < 0)
1191                 return ret;
1192
1193 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
1194         if (!iommu_present(&platform_bus_type))
1195                 bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1196 #endif
1197
1198         setup_done = true;
1199         return 0;
1200 }
1201 subsys_initcall(ipmmu_init);