drivers/iommu/ipmmu-vmsa.c

   1 /*
   2  * IPMMU VMSA
   3  *
   4  * Copyright (C) 2014 Renesas Electronics Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  */
  10
  11 #include <linux/bitmap.h>
  12 #include <linux/delay.h>
  13 #include <linux/dma-iommu.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/err.h>
  16 #include <linux/export.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/iommu.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/of_iommu.h>
  24 #include <linux/of_platform.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/sizes.h>
  27 #include <linux/slab.h>
  28 #include <linux/sys_soc.h>
  29
  30 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
  31 #include <asm/dma-iommu.h>
  32 #include <asm/pgalloc.h>
  33 #else
  34 #define arm_iommu_create_mapping(...)   NULL
  35 #define arm_iommu_attach_device(...)    -ENODEV
  36 #define arm_iommu_release_mapping(...)  do {} while (0)
  37 #define arm_iommu_detach_device(...)    do {} while (0)
  38 #endif
  39
  40 #include "io-pgtable.h"
  41
  42 #define IPMMU_CTX_MAX 8
  43
  44 struct ipmmu_features {
  45         bool use_ns_alias_offset;
  46         bool has_cache_leaf_nodes;
  47         unsigned int number_of_contexts;
  48         bool setup_imbuscr;
  49         bool twobit_imttbcr_sl0;
  50 };
  51
  52 struct ipmmu_vmsa_device {
  53         struct device *dev;
  54         void __iomem *base;
  55         struct iommu_device iommu;
  56         struct ipmmu_vmsa_device *root;
  57         const struct ipmmu_features *features;
  58         unsigned int num_utlbs;
  59         unsigned int num_ctx;
  60         spinlock_t lock;                        /* Protects ctx and domains[] */
  61         DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
  62         struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
  63
  64         struct iommu_group *group;
  65         struct dma_iommu_mapping *mapping;
  66 };
  67
  68 struct ipmmu_vmsa_domain {
  69         struct ipmmu_vmsa_device *mmu;
  70         struct iommu_domain io_domain;
  71
  72         struct io_pgtable_cfg cfg;
  73         struct io_pgtable_ops *iop;
  74
  75         unsigned int context_id;
  76         spinlock_t lock;                        /* Protects mappings */
  77 };
  78
  79 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
  80 {
  81         return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
  82 }
  83
  84 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
  85 {
  86         return dev->iommu_fwspec ? dev->iommu_fwspec->iommu_priv : NULL;
  87 }
  88
  89 #define TLB_LOOP_TIMEOUT                100     /* 100us */
  90
  91 /* -----------------------------------------------------------------------------
  92  * Registers Definition
  93  */
  94
  95 #define IM_NS_ALIAS_OFFSET              0x800
  96
  97 #define IM_CTX_SIZE                     0x40
  98
  99 #define IMCTR                           0x0000
 100 #define IMCTR_TRE                       (1 << 17)
 101 #define IMCTR_AFE                       (1 << 16)
 102 #define IMCTR_RTSEL_MASK                (3 << 4)
 103 #define IMCTR_RTSEL_SHIFT               4
 104 #define IMCTR_TREN                      (1 << 3)
 105 #define IMCTR_INTEN                     (1 << 2)
 106 #define IMCTR_FLUSH                     (1 << 1)
 107 #define IMCTR_MMUEN                     (1 << 0)
 108
 109 #define IMCAAR                          0x0004
 110
 111 #define IMTTBCR                         0x0008
 112 #define IMTTBCR_EAE                     (1 << 31)
 113 #define IMTTBCR_PMB                     (1 << 30)
 114 #define IMTTBCR_SH1_NON_SHAREABLE       (0 << 28)
 115 #define IMTTBCR_SH1_OUTER_SHAREABLE     (2 << 28)
 116 #define IMTTBCR_SH1_INNER_SHAREABLE     (3 << 28)
 117 #define IMTTBCR_SH1_MASK                (3 << 28)
 118 #define IMTTBCR_ORGN1_NC                (0 << 26)
 119 #define IMTTBCR_ORGN1_WB_WA             (1 << 26)
 120 #define IMTTBCR_ORGN1_WT                (2 << 26)
 121 #define IMTTBCR_ORGN1_WB                (3 << 26)
 122 #define IMTTBCR_ORGN1_MASK              (3 << 26)
 123 #define IMTTBCR_IRGN1_NC                (0 << 24)
 124 #define IMTTBCR_IRGN1_WB_WA             (1 << 24)
 125 #define IMTTBCR_IRGN1_WT                (2 << 24)
 126 #define IMTTBCR_IRGN1_WB                (3 << 24)
 127 #define IMTTBCR_IRGN1_MASK              (3 << 24)
 128 #define IMTTBCR_TSZ1_MASK               (7 << 16)
 129 #define IMTTBCR_TSZ1_SHIFT              16
 130 #define IMTTBCR_SH0_NON_SHAREABLE       (0 << 12)
 131 #define IMTTBCR_SH0_OUTER_SHAREABLE     (2 << 12)
 132 #define IMTTBCR_SH0_INNER_SHAREABLE     (3 << 12)
 133 #define IMTTBCR_SH0_MASK                (3 << 12)
 134 #define IMTTBCR_ORGN0_NC                (0 << 10)
 135 #define IMTTBCR_ORGN0_WB_WA             (1 << 10)
 136 #define IMTTBCR_ORGN0_WT                (2 << 10)
 137 #define IMTTBCR_ORGN0_WB                (3 << 10)
 138 #define IMTTBCR_ORGN0_MASK              (3 << 10)
 139 #define IMTTBCR_IRGN0_NC                (0 << 8)
 140 #define IMTTBCR_IRGN0_WB_WA             (1 << 8)
 141 #define IMTTBCR_IRGN0_WT                (2 << 8)
 142 #define IMTTBCR_IRGN0_WB                (3 << 8)
 143 #define IMTTBCR_IRGN0_MASK              (3 << 8)
 144 #define IMTTBCR_SL0_LVL_2               (0 << 4)
 145 #define IMTTBCR_SL0_LVL_1               (1 << 4)
 146 #define IMTTBCR_TSZ0_MASK               (7 << 0)
 147 #define IMTTBCR_TSZ0_SHIFT              O
 148
 149 #define IMTTBCR_SL0_TWOBIT_LVL_3        (0 << 6)
 150 #define IMTTBCR_SL0_TWOBIT_LVL_2        (1 << 6)
 151 #define IMTTBCR_SL0_TWOBIT_LVL_1        (2 << 6)
 152
 153 #define IMBUSCR                         0x000c
 154 #define IMBUSCR_DVM                     (1 << 2)
 155 #define IMBUSCR_BUSSEL_SYS              (0 << 0)
 156 #define IMBUSCR_BUSSEL_CCI              (1 << 0)
 157 #define IMBUSCR_BUSSEL_IMCAAR           (2 << 0)
 158 #define IMBUSCR_BUSSEL_CCI_IMCAAR       (3 << 0)
 159 #define IMBUSCR_BUSSEL_MASK             (3 << 0)
 160
 161 #define IMTTLBR0                        0x0010
 162 #define IMTTUBR0                        0x0014
 163 #define IMTTLBR1                        0x0018
 164 #define IMTTUBR1                        0x001c
 165
 166 #define IMSTR                           0x0020
 167 #define IMSTR_ERRLVL_MASK               (3 << 12)
 168 #define IMSTR_ERRLVL_SHIFT              12
 169 #define IMSTR_ERRCODE_TLB_FORMAT        (1 << 8)
 170 #define IMSTR_ERRCODE_ACCESS_PERM       (4 << 8)
 171 #define IMSTR_ERRCODE_SECURE_ACCESS     (5 << 8)
 172 #define IMSTR_ERRCODE_MASK              (7 << 8)
 173 #define IMSTR_MHIT                      (1 << 4)
 174 #define IMSTR_ABORT                     (1 << 2)
 175 #define IMSTR_PF                        (1 << 1)
 176 #define IMSTR_TF                        (1 << 0)
 177
 178 #define IMMAIR0                         0x0028
 179 #define IMMAIR1                         0x002c
 180 #define IMMAIR_ATTR_MASK                0xff
 181 #define IMMAIR_ATTR_DEVICE              0x04
 182 #define IMMAIR_ATTR_NC                  0x44
 183 #define IMMAIR_ATTR_WBRWA               0xff
 184 #define IMMAIR_ATTR_SHIFT(n)            ((n) << 3)
 185 #define IMMAIR_ATTR_IDX_NC              0
 186 #define IMMAIR_ATTR_IDX_WBRWA           1
 187 #define IMMAIR_ATTR_IDX_DEV             2
 188
 189 #define IMEAR                           0x0030
 190
 191 #define IMPCTR                          0x0200
 192 #define IMPSTR                          0x0208
 193 #define IMPEAR                          0x020c
 194 #define IMPMBA(n)                       (0x0280 + ((n) * 4))
 195 #define IMPMBD(n)                       (0x02c0 + ((n) * 4))
 196
 197 #define IMUCTR(n)                       (0x0300 + ((n) * 16))
 198 #define IMUCTR_FIXADDEN                 (1 << 31)
 199 #define IMUCTR_FIXADD_MASK              (0xff << 16)
 200 #define IMUCTR_FIXADD_SHIFT             16
 201 #define IMUCTR_TTSEL_MMU(n)             ((n) << 4)
 202 #define IMUCTR_TTSEL_PMB                (8 << 4)
 203 #define IMUCTR_TTSEL_MASK               (15 << 4)
 204 #define IMUCTR_FLUSH                    (1 << 1)
 205 #define IMUCTR_MMUEN                    (1 << 0)
 206
 207 #define IMUASID(n)                      (0x0308 + ((n) * 16))
 208 #define IMUASID_ASID8_MASK              (0xff << 8)
 209 #define IMUASID_ASID8_SHIFT             8
 210 #define IMUASID_ASID0_MASK              (0xff << 0)
 211 #define IMUASID_ASID0_SHIFT             0
 212
 213 /* -----------------------------------------------------------------------------
 214  * Root device handling
 215  */
 216
 217 static struct platform_driver ipmmu_driver;
 218
 219 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
 220 {
 221         return mmu->root == mmu;
 222 }
 223
 224 static int __ipmmu_check_device(struct device *dev, void *data)
 225 {
 226         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
 227         struct ipmmu_vmsa_device **rootp = data;
 228
 229         if (ipmmu_is_root(mmu))
 230                 *rootp = mmu;
 231
 232         return 0;
 233 }
 234
 235 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
 236 {
 237         struct ipmmu_vmsa_device *root = NULL;
 238
 239         return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
 240                                       __ipmmu_check_device) == 0 ? root : NULL;
 241 }
 242
 243 /* -----------------------------------------------------------------------------
 244  * Read/Write Access
 245  */
 246
 247 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
 248 {
 249         return ioread32(mmu->base + offset);
 250 }
 251
 252 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 253                         u32 data)
 254 {
 255         iowrite32(data, mmu->base + offset);
 256 }
 257
 258 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 259                                unsigned int reg)
 260 {
 261         return ipmmu_read(domain->mmu->root,
 262                           domain->context_id * IM_CTX_SIZE + reg);
 263 }
 264
 265 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 266                                  unsigned int reg, u32 data)
 267 {
 268         ipmmu_write(domain->mmu->root,
 269                     domain->context_id * IM_CTX_SIZE + reg, data);
 270 }
 271
 272 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 273                                 unsigned int reg, u32 data)
 274 {
 275         if (domain->mmu != domain->mmu->root)
 276                 ipmmu_write(domain->mmu,
 277                             domain->context_id * IM_CTX_SIZE + reg, data);
 278
 279         ipmmu_write(domain->mmu->root,
 280                     domain->context_id * IM_CTX_SIZE + reg, data);
 281 }
 282
 283 /* -----------------------------------------------------------------------------
 284  * TLB and microTLB Management
 285  */
 286
 287 /* Wait for any pending TLB invalidations to complete */
 288 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
 289 {
 290         unsigned int count = 0;
 291
 292         while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
 293                 cpu_relax();
 294                 if (++count == TLB_LOOP_TIMEOUT) {
 295                         dev_err_ratelimited(domain->mmu->dev,
 296                         "TLB sync timed out -- MMU may be deadlocked\n");
 297                         return;
 298                 }
 299                 udelay(1);
 300         }
 301 }
 302
 303 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
 304 {
 305         u32 reg;
 306
 307         reg = ipmmu_ctx_read_root(domain, IMCTR);
 308         reg |= IMCTR_FLUSH;
 309         ipmmu_ctx_write_all(domain, IMCTR, reg);
 310
 311         ipmmu_tlb_sync(domain);
 312 }
 313
 314 /*
 315  * Enable MMU translation for the microTLB.
 316  */
 317 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 318                               unsigned int utlb)
 319 {
 320         struct ipmmu_vmsa_device *mmu = domain->mmu;
 321
 322         /*
 323          * TODO: Reference-count the microTLB as several bus masters can be
 324          * connected to the same microTLB.
 325          */
 326
 327         /* TODO: What should we set the ASID to ? */
 328         ipmmu_write(mmu, IMUASID(utlb), 0);
 329         /* TODO: Do we need to flush the microTLB ? */
 330         ipmmu_write(mmu, IMUCTR(utlb),
 331                     IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_FLUSH |
 332                     IMUCTR_MMUEN);
 333 }
 334
 335 /*
 336  * Disable MMU translation for the microTLB.
 337  */
 338 static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 339                                unsigned int utlb)
 340 {
 341         struct ipmmu_vmsa_device *mmu = domain->mmu;
 342
 343         ipmmu_write(mmu, IMUCTR(utlb), 0);
 344 }
 345
 346 static void ipmmu_tlb_flush_all(void *cookie)
 347 {
 348         struct ipmmu_vmsa_domain *domain = cookie;
 349
 350         ipmmu_tlb_invalidate(domain);
 351 }
 352
 353 static void ipmmu_tlb_add_flush(unsigned long iova, size_t size,
 354                                 size_t granule, bool leaf, void *cookie)
 355 {
 356         /* The hardware doesn't support selective TLB flush. */
 357 }
 358
 359 static const struct iommu_gather_ops ipmmu_gather_ops = {
 360         .tlb_flush_all = ipmmu_tlb_flush_all,
 361         .tlb_add_flush = ipmmu_tlb_add_flush,
 362         .tlb_sync = ipmmu_tlb_flush_all,
 363 };
 364
 365 /* -----------------------------------------------------------------------------
 366  * Domain/Context Management
 367  */
 368
 369 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
 370                                          struct ipmmu_vmsa_domain *domain)
 371 {
 372         unsigned long flags;
 373         int ret;
 374
 375         spin_lock_irqsave(&mmu->lock, flags);
 376
 377         ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
 378         if (ret != mmu->num_ctx) {
 379                 mmu->domains[ret] = domain;
 380                 set_bit(ret, mmu->ctx);
 381         } else
 382                 ret = -EBUSY;
 383
 384         spin_unlock_irqrestore(&mmu->lock, flags);
 385
 386         return ret;
 387 }
 388
 389 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 390                                       unsigned int context_id)
 391 {
 392         unsigned long flags;
 393
 394         spin_lock_irqsave(&mmu->lock, flags);
 395
 396         clear_bit(context_id, mmu->ctx);
 397         mmu->domains[context_id] = NULL;
 398
 399         spin_unlock_irqrestore(&mmu->lock, flags);
 400 }
 401
 402 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 403 {
 404         u64 ttbr;
 405         u32 tmp;
 406         int ret;
 407
 408         /*
 409          * Allocate the page table operations.
 410          *
 411          * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
 412          * access, Long-descriptor format" that the NStable bit being set in a
 413          * table descriptor will result in the NStable and NS bits of all child
 414          * entries being ignored and considered as being set. The IPMMU seems
 415          * not to comply with this, as it generates a secure access page fault
 416          * if any of the NStable and NS bits isn't set when running in
 417          * non-secure mode.
 418          */
 419         domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
 420         domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
 421         domain->cfg.ias = 32;
 422         domain->cfg.oas = 40;
 423         domain->cfg.tlb = &ipmmu_gather_ops;
 424         domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
 425         domain->io_domain.geometry.force_aperture = true;
 426         /*
 427          * TODO: Add support for coherent walk through CCI with DVM and remove
 428          * cache handling. For now, delegate it to the io-pgtable code.
 429          */
 430         domain->cfg.iommu_dev = domain->mmu->root->dev;
 431
 432         /*
 433          * Find an unused context.
 434          */
 435         ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
 436         if (ret < 0)
 437                 return ret;
 438
 439         domain->context_id = ret;
 440
 441         domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 442                                            domain);
 443         if (!domain->iop) {
 444                 ipmmu_domain_free_context(domain->mmu->root,
 445                                           domain->context_id);
 446                 return -EINVAL;
 447         }
 448
 449         /* TTBR0 */
 450         ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
 451         ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
 452         ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 453
 454         /*
 455          * TTBCR
 456          * We use long descriptors with inner-shareable WBWA tables and allocate
 457          * the whole 32-bit VA space to TTBR0.
 458          */
 459         if (domain->mmu->features->twobit_imttbcr_sl0)
 460                 tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
 461         else
 462                 tmp = IMTTBCR_SL0_LVL_1;
 463
 464         ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE |
 465                              IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
 466                              IMTTBCR_IRGN0_WB_WA | tmp);
 467
 468         /* MAIR0 */
 469         ipmmu_ctx_write_root(domain, IMMAIR0,
 470                              domain->cfg.arm_lpae_s1_cfg.mair[0]);
 471
 472         /* IMBUSCR */
 473         if (domain->mmu->features->setup_imbuscr)
 474                 ipmmu_ctx_write_root(domain, IMBUSCR,
 475                                      ipmmu_ctx_read_root(domain, IMBUSCR) &
 476                                      ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 477
 478         /*
 479          * IMSTR
 480          * Clear all interrupt flags.
 481          */
 482         ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
 483
 484         /*
 485          * IMCTR
 486          * Enable the MMU and interrupt generation. The long-descriptor
 487          * translation table format doesn't use TEX remapping. Don't enable AF
 488          * software management as we have no use for it. Flush the TLB as
 489          * required when modifying the context registers.
 490          */
 491         ipmmu_ctx_write_all(domain, IMCTR,
 492                             IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 493
 494         return 0;
 495 }
 496
 497 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 498 {
 499         /*
 500          * Disable the context. Flush the TLB as required when modifying the
 501          * context registers.
 502          *
 503          * TODO: Is TLB flush really needed ?
 504          */
 505         ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
 506         ipmmu_tlb_sync(domain);
 507         ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
 508 }
 509
 510 /* -----------------------------------------------------------------------------
 511  * Fault Handling
 512  */
 513
 514 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 515 {
 516         const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
 517         struct ipmmu_vmsa_device *mmu = domain->mmu;
 518         u32 status;
 519         u32 iova;
 520
 521         status = ipmmu_ctx_read_root(domain, IMSTR);
 522         if (!(status & err_mask))
 523                 return IRQ_NONE;
 524
 525         iova = ipmmu_ctx_read_root(domain, IMEAR);
 526
 527         /*
 528          * Clear the error status flags. Unlike traditional interrupt flag
 529          * registers that must be cleared by writing 1, this status register
 530          * seems to require 0. The error address register must be read before,
 531          * otherwise its value will be 0.
 532          */
 533         ipmmu_ctx_write_root(domain, IMSTR, 0);
 534
 535         /* Log fatal errors. */
 536         if (status & IMSTR_MHIT)
 537                 dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%08x\n",
 538                                     iova);
 539         if (status & IMSTR_ABORT)
 540                 dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%08x\n",
 541                                     iova);
 542
 543         if (!(status & (IMSTR_PF | IMSTR_TF)))
 544                 return IRQ_NONE;
 545
 546         /*
 547          * Try to handle page faults and translation faults.
 548          *
 549          * TODO: We need to look up the faulty device based on the I/O VA. Use
 550          * the IOMMU device for now.
 551          */
 552         if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
 553                 return IRQ_HANDLED;
 554
 555         dev_err_ratelimited(mmu->dev,
 556                             "Unhandled fault: status 0x%08x iova 0x%08x\n",
 557                             status, iova);
 558
 559         return IRQ_HANDLED;
 560 }
 561
 562 static irqreturn_t ipmmu_irq(int irq, void *dev)
 563 {
 564         struct ipmmu_vmsa_device *mmu = dev;
 565         irqreturn_t status = IRQ_NONE;
 566         unsigned int i;
 567         unsigned long flags;
 568
 569         spin_lock_irqsave(&mmu->lock, flags);
 570
 571         /*
 572          * Check interrupts for all active contexts.
 573          */
 574         for (i = 0; i < mmu->num_ctx; i++) {
 575                 if (!mmu->domains[i])
 576                         continue;
 577                 if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
 578                         status = IRQ_HANDLED;
 579         }
 580
 581         spin_unlock_irqrestore(&mmu->lock, flags);
 582
 583         return status;
 584 }
 585
 586 /* -----------------------------------------------------------------------------
 587  * IOMMU Operations
 588  */
 589
 590 static struct iommu_domain *__ipmmu_domain_alloc(unsigned type)
 591 {
 592         struct ipmmu_vmsa_domain *domain;
 593
 594         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 595         if (!domain)
 596                 return NULL;
 597
 598         spin_lock_init(&domain->lock);
 599
 600         return &domain->io_domain;
 601 }
 602
 603 static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
 604 {
 605         struct iommu_domain *io_domain = NULL;
 606
 607         switch (type) {
 608         case IOMMU_DOMAIN_UNMANAGED:
 609                 io_domain = __ipmmu_domain_alloc(type);
 610                 break;
 611
 612         case IOMMU_DOMAIN_DMA:
 613                 io_domain = __ipmmu_domain_alloc(type);
 614                 if (io_domain && iommu_get_dma_cookie(io_domain)) {
 615                         kfree(io_domain);
 616                         io_domain = NULL;
 617                 }
 618                 break;
 619         }
 620
 621         return io_domain;
 622 }
 623
 624 static void ipmmu_domain_free(struct iommu_domain *io_domain)
 625 {
 626         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 627
 628         /*
 629          * Free the domain resources. We assume that all devices have already
 630          * been detached.
 631          */
 632         iommu_put_dma_cookie(io_domain);
 633         ipmmu_domain_destroy_context(domain);
 634         free_io_pgtable_ops(domain->iop);
 635         kfree(domain);
 636 }
 637
 638 static int ipmmu_attach_device(struct iommu_domain *io_domain,
 639                                struct device *dev)
 640 {
 641         struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 642         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 643         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 644         unsigned long flags;
 645         unsigned int i;
 646         int ret = 0;
 647
 648         if (!mmu) {
 649                 dev_err(dev, "Cannot attach to IPMMU\n");
 650                 return -ENXIO;
 651         }
 652
 653         spin_lock_irqsave(&domain->lock, flags);
 654
 655         if (!domain->mmu) {
 656                 /* The domain hasn't been used yet, initialize it. */
 657                 domain->mmu = mmu;
 658                 ret = ipmmu_domain_init_context(domain);
 659                 if (ret < 0) {
 660                         dev_err(dev, "Unable to initialize IPMMU context\n");
 661                         domain->mmu = NULL;
 662                 } else {
 663                         dev_info(dev, "Using IPMMU context %u\n",
 664                                  domain->context_id);
 665                 }
 666         } else if (domain->mmu != mmu) {
 667                 /*
 668                  * Something is wrong, we can't attach two devices using
 669                  * different IOMMUs to the same domain.
 670                  */
 671                 dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
 672                         dev_name(mmu->dev), dev_name(domain->mmu->dev));
 673                 ret = -EINVAL;
 674         } else
 675                 dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
 676
 677         spin_unlock_irqrestore(&domain->lock, flags);
 678
 679         if (ret < 0)
 680                 return ret;
 681
 682         for (i = 0; i < fwspec->num_ids; ++i)
 683                 ipmmu_utlb_enable(domain, fwspec->ids[i]);
 684
 685         return 0;
 686 }
 687
 688 static void ipmmu_detach_device(struct iommu_domain *io_domain,
 689                                 struct device *dev)
 690 {
 691         struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 692         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 693         unsigned int i;
 694
 695         for (i = 0; i < fwspec->num_ids; ++i)
 696                 ipmmu_utlb_disable(domain, fwspec->ids[i]);
 697
 698         /*
 699          * TODO: Optimize by disabling the context when no device is attached.
 700          */
 701 }
 702
 703 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 704                      phys_addr_t paddr, size_t size, int prot)
 705 {
 706         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 707
 708         if (!domain)
 709                 return -ENODEV;
 710
 711         return domain->iop->map(domain->iop, iova, paddr, size, prot);
 712 }
 713
 714 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
 715                           size_t size)
 716 {
 717         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 718
 719         return domain->iop->unmap(domain->iop, iova, size);
 720 }
 721
 722 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain)
 723 {
 724         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 725
 726         if (domain->mmu)
 727                 ipmmu_tlb_flush_all(domain);
 728 }
 729
 730 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 731                                       dma_addr_t iova)
 732 {
 733         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 734
 735         /* TODO: Is locking needed ? */
 736
 737         return domain->iop->iova_to_phys(domain->iop, iova);
 738 }
 739
 740 static int ipmmu_init_platform_device(struct device *dev,
 741                                       struct of_phandle_args *args)
 742 {
 743         struct platform_device *ipmmu_pdev;
 744
 745         ipmmu_pdev = of_find_device_by_node(args->np);
 746         if (!ipmmu_pdev)
 747                 return -ENODEV;
 748
 749         dev->iommu_fwspec->iommu_priv = platform_get_drvdata(ipmmu_pdev);
 750         return 0;
 751 }
 752
 753 static bool ipmmu_slave_whitelist(struct device *dev)
 754 {
 755         /* By default, do not allow use of IPMMU */
 756         return false;
 757 }
 758
 759 static const struct soc_device_attribute soc_r8a7795[] = {
 760         { .soc_id = "r8a7795", },
 761         { /* sentinel */ }
 762 };
 763
 764 static int ipmmu_of_xlate(struct device *dev,
 765                           struct of_phandle_args *spec)
 766 {
 767         /* For R-Car Gen3 use a white list to opt-in slave devices */
 768         if (soc_device_match(soc_r8a7795) && !ipmmu_slave_whitelist(dev))
 769                 return -ENODEV;
 770
 771         iommu_fwspec_add_ids(dev, spec->args, 1);
 772
 773         /* Initialize once - xlate() will call multiple times */
 774         if (to_ipmmu(dev))
 775                 return 0;
 776
 777         return ipmmu_init_platform_device(dev, spec);
 778 }
 779
 780 static int ipmmu_init_arm_mapping(struct device *dev)
 781 {
 782         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 783         struct iommu_group *group;
 784         int ret;
 785
 786         /* Create a device group and add the device to it. */
 787         group = iommu_group_alloc();
 788         if (IS_ERR(group)) {
 789                 dev_err(dev, "Failed to allocate IOMMU group\n");
 790                 return PTR_ERR(group);
 791         }
 792
 793         ret = iommu_group_add_device(group, dev);
 794         iommu_group_put(group);
 795
 796         if (ret < 0) {
 797                 dev_err(dev, "Failed to add device to IPMMU group\n");
 798                 return ret;
 799         }
 800
 801         /*
 802          * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 803          * VAs. This will allocate a corresponding IOMMU domain.
 804          *
 805          * TODO:
 806          * - Create one mapping per context (TLB).
 807          * - Make the mapping size configurable ? We currently use a 2GB mapping
 808          *   at a 1GB offset to ensure that NULL VAs will fault.
 809          */
 810         if (!mmu->mapping) {
 811                 struct dma_iommu_mapping *mapping;
 812
 813                 mapping = arm_iommu_create_mapping(&platform_bus_type,
 814                                                    SZ_1G, SZ_2G);
 815                 if (IS_ERR(mapping)) {
 816                         dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 817                         ret = PTR_ERR(mapping);
 818                         goto error;
 819                 }
 820
 821                 mmu->mapping = mapping;
 822         }
 823
 824         /* Attach the ARM VA mapping to the device. */
 825         ret = arm_iommu_attach_device(dev, mmu->mapping);
 826         if (ret < 0) {
 827                 dev_err(dev, "Failed to attach device to VA mapping\n");
 828                 goto error;
 829         }
 830
 831         return 0;
 832
 833 error:
 834         iommu_group_remove_device(dev);
 835         if (mmu->mapping)
 836                 arm_iommu_release_mapping(mmu->mapping);
 837
 838         return ret;
 839 }
 840
 841 static int ipmmu_add_device(struct device *dev)
 842 {
 843         struct iommu_group *group;
 844
 845         /*
 846          * Only let through devices that have been verified in xlate()
 847          */
 848         if (!to_ipmmu(dev))
 849                 return -ENODEV;
 850
 851         if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
 852                 return ipmmu_init_arm_mapping(dev);
 853
 854         group = iommu_group_get_for_dev(dev);
 855         if (IS_ERR(group))
 856                 return PTR_ERR(group);
 857
 858         iommu_group_put(group);
 859         return 0;
 860 }
 861
 862 static void ipmmu_remove_device(struct device *dev)
 863 {
 864         arm_iommu_detach_device(dev);
 865         iommu_group_remove_device(dev);
 866 }
 867
 868 static struct iommu_group *ipmmu_find_group(struct device *dev)
 869 {
 870         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 871         struct iommu_group *group;
 872
 873         if (mmu->group)
 874                 return iommu_group_ref_get(mmu->group);
 875
 876         group = iommu_group_alloc();
 877         if (!IS_ERR(group))
 878                 mmu->group = group;
 879
 880         return group;
 881 }
 882
 883 static const struct iommu_ops ipmmu_ops = {
 884         .domain_alloc = ipmmu_domain_alloc,
 885         .domain_free = ipmmu_domain_free,
 886         .attach_dev = ipmmu_attach_device,
 887         .detach_dev = ipmmu_detach_device,
 888         .map = ipmmu_map,
 889         .unmap = ipmmu_unmap,
 890         .flush_iotlb_all = ipmmu_iotlb_sync,
 891         .iotlb_sync = ipmmu_iotlb_sync,
 892         .map_sg = default_iommu_map_sg,
 893         .iova_to_phys = ipmmu_iova_to_phys,
 894         .add_device = ipmmu_add_device,
 895         .remove_device = ipmmu_remove_device,
 896         .device_group = ipmmu_find_group,
 897         .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 898         .of_xlate = ipmmu_of_xlate,
 899 };
 900
 901 /* -----------------------------------------------------------------------------
 902  * Probe/remove and init
 903  */
 904
 905 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 906 {
 907         unsigned int i;
 908
 909         /* Disable all contexts. */
 910         for (i = 0; i < mmu->num_ctx; ++i)
 911                 ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
 912 }
 913
 914 static const struct ipmmu_features ipmmu_features_default = {
 915         .use_ns_alias_offset = true,
 916         .has_cache_leaf_nodes = false,
 917         .number_of_contexts = 1, /* software only tested with one context */
 918         .setup_imbuscr = true,
 919         .twobit_imttbcr_sl0 = false,
 920 };
 921
 922 static const struct ipmmu_features ipmmu_features_r8a7795 = {
 923         .use_ns_alias_offset = false,
 924         .has_cache_leaf_nodes = true,
 925         .number_of_contexts = 8,
 926         .setup_imbuscr = false,
 927         .twobit_imttbcr_sl0 = true,
 928 };
 929
 930 static const struct of_device_id ipmmu_of_ids[] = {
 931         {
 932                 .compatible = "renesas,ipmmu-vmsa",
 933                 .data = &ipmmu_features_default,
 934         }, {
 935                 .compatible = "renesas,ipmmu-r8a7795",
 936                 .data = &ipmmu_features_r8a7795,
 937         }, {
 938                 /* Terminator */
 939         },
 940 };
 941
 942 MODULE_DEVICE_TABLE(of, ipmmu_of_ids);
 943
 944 static int ipmmu_probe(struct platform_device *pdev)
 945 {
 946         struct ipmmu_vmsa_device *mmu;
 947         struct resource *res;
 948         int irq;
 949         int ret;
 950
 951         mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
 952         if (!mmu) {
 953                 dev_err(&pdev->dev, "cannot allocate device data\n");
 954                 return -ENOMEM;
 955         }
 956
 957         mmu->dev = &pdev->dev;
 958         mmu->num_utlbs = 32;
 959         spin_lock_init(&mmu->lock);
 960         bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
 961         mmu->features = of_device_get_match_data(&pdev->dev);
 962         dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
 963
 964         /* Map I/O memory and request IRQ. */
 965         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 966         mmu->base = devm_ioremap_resource(&pdev->dev, res);
 967         if (IS_ERR(mmu->base))
 968                 return PTR_ERR(mmu->base);
 969
 970         /*
 971          * The IPMMU has two register banks, for secure and non-secure modes.
 972          * The bank mapped at the beginning of the IPMMU address space
 973          * corresponds to the running mode of the CPU. When running in secure
 974          * mode the non-secure register bank is also available at an offset.
 975          *
 976          * Secure mode operation isn't clearly documented and is thus currently
 977          * not implemented in the driver. Furthermore, preliminary tests of
 978          * non-secure operation with the main register bank were not successful.
 979          * Offset the registers base unconditionally to point to the non-secure
 980          * alias space for now.
 981          */
 982         if (mmu->features->use_ns_alias_offset)
 983                 mmu->base += IM_NS_ALIAS_OFFSET;
 984
 985         mmu->num_ctx = min_t(unsigned int, IPMMU_CTX_MAX,
 986                              mmu->features->number_of_contexts);
 987
 988         irq = platform_get_irq(pdev, 0);
 989
 990         /*
 991          * Determine if this IPMMU instance is a root device by checking for
 992          * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
 993          */
 994         if (!mmu->features->has_cache_leaf_nodes ||
 995             !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
 996                 mmu->root = mmu;
 997         else
 998                 mmu->root = ipmmu_find_root();
 999
1000         /*
1001          * Wait until the root device has been registered for sure.
1002          */
1003         if (!mmu->root)
1004                 return -EPROBE_DEFER;
1005
1006         /* Root devices have mandatory IRQs */
1007         if (ipmmu_is_root(mmu)) {
1008                 if (irq < 0) {
1009                         dev_err(&pdev->dev, "no IRQ found\n");
1010                         return irq;
1011                 }
1012
1013                 ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1014                                        dev_name(&pdev->dev), mmu);
1015                 if (ret < 0) {
1016                         dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1017                         return ret;
1018                 }
1019
1020                 ipmmu_device_reset(mmu);
1021         }
1022
1023         /*
1024          * Register the IPMMU to the IOMMU subsystem in the following cases:
1025          * - R-Car Gen2 IPMMU (all devices registered)
1026          * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1027          */
1028         if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1029                 ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1030                                              dev_name(&pdev->dev));
1031                 if (ret)
1032                         return ret;
1033
1034                 iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
1035                 iommu_device_set_fwnode(&mmu->iommu,
1036                                         &pdev->dev.of_node->fwnode);
1037
1038                 ret = iommu_device_register(&mmu->iommu);
1039                 if (ret)
1040                         return ret;
1041
1042 #if defined(CONFIG_IOMMU_DMA)
1043                 if (!iommu_present(&platform_bus_type))
1044                         bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1045 #endif
1046         }
1047
1048         /*
1049          * We can't create the ARM mapping here as it requires the bus to have
1050          * an IOMMU, which only happens when bus_set_iommu() is called in
1051          * ipmmu_init() after the probe function returns.
1052          */
1053
1054         platform_set_drvdata(pdev, mmu);
1055
1056         return 0;
1057 }
1058
1059 static int ipmmu_remove(struct platform_device *pdev)
1060 {
1061         struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1062
1063         iommu_device_sysfs_remove(&mmu->iommu);
1064         iommu_device_unregister(&mmu->iommu);
1065
1066         arm_iommu_release_mapping(mmu->mapping);
1067
1068         ipmmu_device_reset(mmu);
1069
1070         return 0;
1071 }
1072
1073 static struct platform_driver ipmmu_driver = {
1074         .driver = {
1075                 .name = "ipmmu-vmsa",
1076                 .of_match_table = of_match_ptr(ipmmu_of_ids),
1077         },
1078         .probe = ipmmu_probe,
1079         .remove = ipmmu_remove,
1080 };
1081
1082 static int __init ipmmu_init(void)
1083 {
1084         static bool setup_done;
1085         int ret;
1086
1087         if (setup_done)
1088                 return 0;
1089
1090         ret = platform_driver_register(&ipmmu_driver);
1091         if (ret < 0)
1092                 return ret;
1093
1094 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
1095         if (!iommu_present(&platform_bus_type))
1096                 bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1097 #endif
1098
1099         setup_done = true;
1100         return 0;
1101 }
1102
1103 static void __exit ipmmu_exit(void)
1104 {
1105         return platform_driver_unregister(&ipmmu_driver);
1106 }
1107
1108 subsys_initcall(ipmmu_init);
1109 module_exit(ipmmu_exit);
1110
1111 MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
1112 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
1113 MODULE_LICENSE("GPL v2");