drivers/iommu/ipmmu-vmsa.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * IPMMU VMSA
   4  *
   5  * Copyright (C) 2014 Renesas Electronics Corporation
   6  */
   7
   8 #include <linux/bitmap.h>
   9 #include <linux/delay.h>
  10 #include <linux/dma-iommu.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/err.h>
  13 #include <linux/export.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16 #include <linux/iommu.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/of_device.h>
  20 #include <linux/of_iommu.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/sizes.h>
  24 #include <linux/slab.h>
  25 #include <linux/sys_soc.h>
  26
  27 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
  28 #include <asm/dma-iommu.h>
  29 #include <asm/pgalloc.h>
  30 #else
  31 #define arm_iommu_create_mapping(...)   NULL
  32 #define arm_iommu_attach_device(...)    -ENODEV
  33 #define arm_iommu_release_mapping(...)  do {} while (0)
  34 #define arm_iommu_detach_device(...)    do {} while (0)
  35 #endif
  36
  37 #include "io-pgtable.h"
  38
  39 #define IPMMU_CTX_MAX 8
  40
  41 struct ipmmu_features {
  42         bool use_ns_alias_offset;
  43         bool has_cache_leaf_nodes;
  44         unsigned int number_of_contexts;
  45         bool setup_imbuscr;
  46         bool twobit_imttbcr_sl0;
  47         bool reserved_context;
  48 };
  49
  50 struct ipmmu_vmsa_device {
  51         struct device *dev;
  52         void __iomem *base;
  53         struct iommu_device iommu;
  54         struct ipmmu_vmsa_device *root;
  55         const struct ipmmu_features *features;
  56         unsigned int num_utlbs;
  57         unsigned int num_ctx;
  58         spinlock_t lock;                        /* Protects ctx and domains[] */
  59         DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
  60         struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
  61
  62         struct iommu_group *group;
  63         struct dma_iommu_mapping *mapping;
  64 };
  65
  66 struct ipmmu_vmsa_domain {
  67         struct ipmmu_vmsa_device *mmu;
  68         struct iommu_domain io_domain;
  69
  70         struct io_pgtable_cfg cfg;
  71         struct io_pgtable_ops *iop;
  72
  73         unsigned int context_id;
  74         struct mutex mutex;                     /* Protects mappings */
  75 };
  76
  77 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
  78 {
  79         return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
  80 }
  81
  82 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
  83 {
  84         return dev->iommu_fwspec ? dev->iommu_fwspec->iommu_priv : NULL;
  85 }
  86
  87 #define TLB_LOOP_TIMEOUT                100     /* 100us */
  88
  89 /* -----------------------------------------------------------------------------
  90  * Registers Definition
  91  */
  92
  93 #define IM_NS_ALIAS_OFFSET              0x800
  94
  95 #define IM_CTX_SIZE                     0x40
  96
  97 #define IMCTR                           0x0000
  98 #define IMCTR_TRE                       (1 << 17)
  99 #define IMCTR_AFE                       (1 << 16)
 100 #define IMCTR_RTSEL_MASK                (3 << 4)
 101 #define IMCTR_RTSEL_SHIFT               4
 102 #define IMCTR_TREN                      (1 << 3)
 103 #define IMCTR_INTEN                     (1 << 2)
 104 #define IMCTR_FLUSH                     (1 << 1)
 105 #define IMCTR_MMUEN                     (1 << 0)
 106
 107 #define IMCAAR                          0x0004
 108
 109 #define IMTTBCR                         0x0008
 110 #define IMTTBCR_EAE                     (1 << 31)
 111 #define IMTTBCR_PMB                     (1 << 30)
 112 #define IMTTBCR_SH1_NON_SHAREABLE       (0 << 28)
 113 #define IMTTBCR_SH1_OUTER_SHAREABLE     (2 << 28)
 114 #define IMTTBCR_SH1_INNER_SHAREABLE     (3 << 28)
 115 #define IMTTBCR_SH1_MASK                (3 << 28)
 116 #define IMTTBCR_ORGN1_NC                (0 << 26)
 117 #define IMTTBCR_ORGN1_WB_WA             (1 << 26)
 118 #define IMTTBCR_ORGN1_WT                (2 << 26)
 119 #define IMTTBCR_ORGN1_WB                (3 << 26)
 120 #define IMTTBCR_ORGN1_MASK              (3 << 26)
 121 #define IMTTBCR_IRGN1_NC                (0 << 24)
 122 #define IMTTBCR_IRGN1_WB_WA             (1 << 24)
 123 #define IMTTBCR_IRGN1_WT                (2 << 24)
 124 #define IMTTBCR_IRGN1_WB                (3 << 24)
 125 #define IMTTBCR_IRGN1_MASK              (3 << 24)
 126 #define IMTTBCR_TSZ1_MASK               (7 << 16)
 127 #define IMTTBCR_TSZ1_SHIFT              16
 128 #define IMTTBCR_SH0_NON_SHAREABLE       (0 << 12)
 129 #define IMTTBCR_SH0_OUTER_SHAREABLE     (2 << 12)
 130 #define IMTTBCR_SH0_INNER_SHAREABLE     (3 << 12)
 131 #define IMTTBCR_SH0_MASK                (3 << 12)
 132 #define IMTTBCR_ORGN0_NC                (0 << 10)
 133 #define IMTTBCR_ORGN0_WB_WA             (1 << 10)
 134 #define IMTTBCR_ORGN0_WT                (2 << 10)
 135 #define IMTTBCR_ORGN0_WB                (3 << 10)
 136 #define IMTTBCR_ORGN0_MASK              (3 << 10)
 137 #define IMTTBCR_IRGN0_NC                (0 << 8)
 138 #define IMTTBCR_IRGN0_WB_WA             (1 << 8)
 139 #define IMTTBCR_IRGN0_WT                (2 << 8)
 140 #define IMTTBCR_IRGN0_WB                (3 << 8)
 141 #define IMTTBCR_IRGN0_MASK              (3 << 8)
 142 #define IMTTBCR_SL0_LVL_2               (0 << 4)
 143 #define IMTTBCR_SL0_LVL_1               (1 << 4)
 144 #define IMTTBCR_TSZ0_MASK               (7 << 0)
 145 #define IMTTBCR_TSZ0_SHIFT              O
 146
 147 #define IMTTBCR_SL0_TWOBIT_LVL_3        (0 << 6)
 148 #define IMTTBCR_SL0_TWOBIT_LVL_2        (1 << 6)
 149 #define IMTTBCR_SL0_TWOBIT_LVL_1        (2 << 6)
 150
 151 #define IMBUSCR                         0x000c
 152 #define IMBUSCR_DVM                     (1 << 2)
 153 #define IMBUSCR_BUSSEL_SYS              (0 << 0)
 154 #define IMBUSCR_BUSSEL_CCI              (1 << 0)
 155 #define IMBUSCR_BUSSEL_IMCAAR           (2 << 0)
 156 #define IMBUSCR_BUSSEL_CCI_IMCAAR       (3 << 0)
 157 #define IMBUSCR_BUSSEL_MASK             (3 << 0)
 158
 159 #define IMTTLBR0                        0x0010
 160 #define IMTTUBR0                        0x0014
 161 #define IMTTLBR1                        0x0018
 162 #define IMTTUBR1                        0x001c
 163
 164 #define IMSTR                           0x0020
 165 #define IMSTR_ERRLVL_MASK               (3 << 12)
 166 #define IMSTR_ERRLVL_SHIFT              12
 167 #define IMSTR_ERRCODE_TLB_FORMAT        (1 << 8)
 168 #define IMSTR_ERRCODE_ACCESS_PERM       (4 << 8)
 169 #define IMSTR_ERRCODE_SECURE_ACCESS     (5 << 8)
 170 #define IMSTR_ERRCODE_MASK              (7 << 8)
 171 #define IMSTR_MHIT                      (1 << 4)
 172 #define IMSTR_ABORT                     (1 << 2)
 173 #define IMSTR_PF                        (1 << 1)
 174 #define IMSTR_TF                        (1 << 0)
 175
 176 #define IMMAIR0                         0x0028
 177 #define IMMAIR1                         0x002c
 178 #define IMMAIR_ATTR_MASK                0xff
 179 #define IMMAIR_ATTR_DEVICE              0x04
 180 #define IMMAIR_ATTR_NC                  0x44
 181 #define IMMAIR_ATTR_WBRWA               0xff
 182 #define IMMAIR_ATTR_SHIFT(n)            ((n) << 3)
 183 #define IMMAIR_ATTR_IDX_NC              0
 184 #define IMMAIR_ATTR_IDX_WBRWA           1
 185 #define IMMAIR_ATTR_IDX_DEV             2
 186
 187 #define IMEAR                           0x0030
 188
 189 #define IMPCTR                          0x0200
 190 #define IMPSTR                          0x0208
 191 #define IMPEAR                          0x020c
 192 #define IMPMBA(n)                       (0x0280 + ((n) * 4))
 193 #define IMPMBD(n)                       (0x02c0 + ((n) * 4))
 194
 195 #define IMUCTR(n)                       ((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
 196 #define IMUCTR0(n)                      (0x0300 + ((n) * 16))
 197 #define IMUCTR32(n)                     (0x0600 + (((n) - 32) * 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)                      ((n) < 32 ? IMUASID0(n) : IMUASID32(n))
 208 #define IMUASID0(n)                     (0x0308 + ((n) * 16))
 209 #define IMUASID32(n)                    (0x0608 + (((n) - 32) * 16))
 210 #define IMUASID_ASID8_MASK              (0xff << 8)
 211 #define IMUASID_ASID8_SHIFT             8
 212 #define IMUASID_ASID0_MASK              (0xff << 0)
 213 #define IMUASID_ASID0_SHIFT             0
 214
 215 /* -----------------------------------------------------------------------------
 216  * Root device handling
 217  */
 218
 219 static struct platform_driver ipmmu_driver;
 220
 221 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
 222 {
 223         return mmu->root == mmu;
 224 }
 225
 226 static int __ipmmu_check_device(struct device *dev, void *data)
 227 {
 228         struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
 229         struct ipmmu_vmsa_device **rootp = data;
 230
 231         if (ipmmu_is_root(mmu))
 232                 *rootp = mmu;
 233
 234         return 0;
 235 }
 236
 237 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
 238 {
 239         struct ipmmu_vmsa_device *root = NULL;
 240
 241         return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
 242                                       __ipmmu_check_device) == 0 ? root : NULL;
 243 }
 244
 245 /* -----------------------------------------------------------------------------
 246  * Read/Write Access
 247  */
 248
 249 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
 250 {
 251         return ioread32(mmu->base + offset);
 252 }
 253
 254 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
 255                         u32 data)
 256 {
 257         iowrite32(data, mmu->base + offset);
 258 }
 259
 260 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
 261                                unsigned int reg)
 262 {
 263         return ipmmu_read(domain->mmu->root,
 264                           domain->context_id * IM_CTX_SIZE + reg);
 265 }
 266
 267 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
 268                                  unsigned int reg, u32 data)
 269 {
 270         ipmmu_write(domain->mmu->root,
 271                     domain->context_id * IM_CTX_SIZE + reg, data);
 272 }
 273
 274 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
 275                                 unsigned int reg, u32 data)
 276 {
 277         if (domain->mmu != domain->mmu->root)
 278                 ipmmu_write(domain->mmu,
 279                             domain->context_id * IM_CTX_SIZE + reg, data);
 280
 281         ipmmu_write(domain->mmu->root,
 282                     domain->context_id * IM_CTX_SIZE + reg, data);
 283 }
 284
 285 /* -----------------------------------------------------------------------------
 286  * TLB and microTLB Management
 287  */
 288
 289 /* Wait for any pending TLB invalidations to complete */
 290 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
 291 {
 292         unsigned int count = 0;
 293
 294         while (ipmmu_ctx_read_root(domain, IMCTR) & IMCTR_FLUSH) {
 295                 cpu_relax();
 296                 if (++count == TLB_LOOP_TIMEOUT) {
 297                         dev_err_ratelimited(domain->mmu->dev,
 298                         "TLB sync timed out -- MMU may be deadlocked\n");
 299                         return;
 300                 }
 301                 udelay(1);
 302         }
 303 }
 304
 305 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
 306 {
 307         u32 reg;
 308
 309         reg = ipmmu_ctx_read_root(domain, IMCTR);
 310         reg |= IMCTR_FLUSH;
 311         ipmmu_ctx_write_all(domain, IMCTR, reg);
 312
 313         ipmmu_tlb_sync(domain);
 314 }
 315
 316 /*
 317  * Enable MMU translation for the microTLB.
 318  */
 319 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
 320                               unsigned int utlb)
 321 {
 322         struct ipmmu_vmsa_device *mmu = domain->mmu;
 323
 324         /*
 325          * TODO: Reference-count the microTLB as several bus masters can be
 326          * connected to the same microTLB.
 327          */
 328
 329         /* TODO: What should we set the ASID to ? */
 330         ipmmu_write(mmu, IMUASID(utlb), 0);
 331         /* TODO: Do we need to flush the microTLB ? */
 332         ipmmu_write(mmu, IMUCTR(utlb),
 333                     IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_FLUSH |
 334                     IMUCTR_MMUEN);
 335 }
 336
 337 /*
 338  * Disable MMU translation for the microTLB.
 339  */
 340 static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
 341                                unsigned int utlb)
 342 {
 343         struct ipmmu_vmsa_device *mmu = domain->mmu;
 344
 345         ipmmu_write(mmu, IMUCTR(utlb), 0);
 346 }
 347
 348 static void ipmmu_tlb_flush_all(void *cookie)
 349 {
 350         struct ipmmu_vmsa_domain *domain = cookie;
 351
 352         ipmmu_tlb_invalidate(domain);
 353 }
 354
 355 static void ipmmu_tlb_add_flush(unsigned long iova, size_t size,
 356                                 size_t granule, bool leaf, void *cookie)
 357 {
 358         /* The hardware doesn't support selective TLB flush. */
 359 }
 360
 361 static const struct iommu_gather_ops ipmmu_gather_ops = {
 362         .tlb_flush_all = ipmmu_tlb_flush_all,
 363         .tlb_add_flush = ipmmu_tlb_add_flush,
 364         .tlb_sync = ipmmu_tlb_flush_all,
 365 };
 366
 367 /* -----------------------------------------------------------------------------
 368  * Domain/Context Management
 369  */
 370
 371 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
 372                                          struct ipmmu_vmsa_domain *domain)
 373 {
 374         unsigned long flags;
 375         int ret;
 376
 377         spin_lock_irqsave(&mmu->lock, flags);
 378
 379         ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
 380         if (ret != mmu->num_ctx) {
 381                 mmu->domains[ret] = domain;
 382                 set_bit(ret, mmu->ctx);
 383         } else
 384                 ret = -EBUSY;
 385
 386         spin_unlock_irqrestore(&mmu->lock, flags);
 387
 388         return ret;
 389 }
 390
 391 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
 392                                       unsigned int context_id)
 393 {
 394         unsigned long flags;
 395
 396         spin_lock_irqsave(&mmu->lock, flags);
 397
 398         clear_bit(context_id, mmu->ctx);
 399         mmu->domains[context_id] = NULL;
 400
 401         spin_unlock_irqrestore(&mmu->lock, flags);
 402 }
 403
 404 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 405 {
 406         u64 ttbr;
 407         u32 tmp;
 408         int ret;
 409
 410         /*
 411          * Allocate the page table operations.
 412          *
 413          * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
 414          * access, Long-descriptor format" that the NStable bit being set in a
 415          * table descriptor will result in the NStable and NS bits of all child
 416          * entries being ignored and considered as being set. The IPMMU seems
 417          * not to comply with this, as it generates a secure access page fault
 418          * if any of the NStable and NS bits isn't set when running in
 419          * non-secure mode.
 420          */
 421         domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
 422         domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
 423         domain->cfg.ias = 32;
 424         domain->cfg.oas = 40;
 425         domain->cfg.tlb = &ipmmu_gather_ops;
 426         domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
 427         domain->io_domain.geometry.force_aperture = true;
 428         /*
 429          * TODO: Add support for coherent walk through CCI with DVM and remove
 430          * cache handling. For now, delegate it to the io-pgtable code.
 431          */
 432         domain->cfg.iommu_dev = domain->mmu->root->dev;
 433
 434         /*
 435          * Find an unused context.
 436          */
 437         ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
 438         if (ret < 0)
 439                 return ret;
 440
 441         domain->context_id = ret;
 442
 443         domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 444                                            domain);
 445         if (!domain->iop) {
 446                 ipmmu_domain_free_context(domain->mmu->root,
 447                                           domain->context_id);
 448                 return -EINVAL;
 449         }
 450
 451         /* TTBR0 */
 452         ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
 453         ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
 454         ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 455
 456         /*
 457          * TTBCR
 458          * We use long descriptors with inner-shareable WBWA tables and allocate
 459          * the whole 32-bit VA space to TTBR0.
 460          */
 461         if (domain->mmu->features->twobit_imttbcr_sl0)
 462                 tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
 463         else
 464                 tmp = IMTTBCR_SL0_LVL_1;
 465
 466         ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE |
 467                              IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
 468                              IMTTBCR_IRGN0_WB_WA | tmp);
 469
 470         /* MAIR0 */
 471         ipmmu_ctx_write_root(domain, IMMAIR0,
 472                              domain->cfg.arm_lpae_s1_cfg.mair[0]);
 473
 474         /* IMBUSCR */
 475         if (domain->mmu->features->setup_imbuscr)
 476                 ipmmu_ctx_write_root(domain, IMBUSCR,
 477                                      ipmmu_ctx_read_root(domain, IMBUSCR) &
 478                                      ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 479
 480         /*
 481          * IMSTR
 482          * Clear all interrupt flags.
 483          */
 484         ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
 485
 486         /*
 487          * IMCTR
 488          * Enable the MMU and interrupt generation. The long-descriptor
 489          * translation table format doesn't use TEX remapping. Don't enable AF
 490          * software management as we have no use for it. Flush the TLB as
 491          * required when modifying the context registers.
 492          */
 493         ipmmu_ctx_write_all(domain, IMCTR,
 494                             IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 495
 496         return 0;
 497 }
 498
 499 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 500 {
 501         if (!domain->mmu)
 502                 return;
 503
 504         /*
 505          * Disable the context. Flush the TLB as required when modifying the
 506          * context registers.
 507          *
 508          * TODO: Is TLB flush really needed ?
 509          */
 510         ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
 511         ipmmu_tlb_sync(domain);
 512         ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
 513 }
 514
 515 /* -----------------------------------------------------------------------------
 516  * Fault Handling
 517  */
 518
 519 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 520 {
 521         const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
 522         struct ipmmu_vmsa_device *mmu = domain->mmu;
 523         u32 status;
 524         u32 iova;
 525
 526         status = ipmmu_ctx_read_root(domain, IMSTR);
 527         if (!(status & err_mask))
 528                 return IRQ_NONE;
 529
 530         iova = ipmmu_ctx_read_root(domain, IMEAR);
 531
 532         /*
 533          * Clear the error status flags. Unlike traditional interrupt flag
 534          * registers that must be cleared by writing 1, this status register
 535          * seems to require 0. The error address register must be read before,
 536          * otherwise its value will be 0.
 537          */
 538         ipmmu_ctx_write_root(domain, IMSTR, 0);
 539
 540         /* Log fatal errors. */
 541         if (status & IMSTR_MHIT)
 542                 dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%08x\n",
 543                                     iova);
 544         if (status & IMSTR_ABORT)
 545                 dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%08x\n",
 546                                     iova);
 547
 548         if (!(status & (IMSTR_PF | IMSTR_TF)))
 549                 return IRQ_NONE;
 550
 551         /*
 552          * Try to handle page faults and translation faults.
 553          *
 554          * TODO: We need to look up the faulty device based on the I/O VA. Use
 555          * the IOMMU device for now.
 556          */
 557         if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
 558                 return IRQ_HANDLED;
 559
 560         dev_err_ratelimited(mmu->dev,
 561                             "Unhandled fault: status 0x%08x iova 0x%08x\n",
 562                             status, iova);
 563
 564         return IRQ_HANDLED;
 565 }
 566
 567 static irqreturn_t ipmmu_irq(int irq, void *dev)
 568 {
 569         struct ipmmu_vmsa_device *mmu = dev;
 570         irqreturn_t status = IRQ_NONE;
 571         unsigned int i;
 572         unsigned long flags;
 573
 574         spin_lock_irqsave(&mmu->lock, flags);
 575
 576         /*
 577          * Check interrupts for all active contexts.
 578          */
 579         for (i = 0; i < mmu->num_ctx; i++) {
 580                 if (!mmu->domains[i])
 581                         continue;
 582                 if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
 583                         status = IRQ_HANDLED;
 584         }
 585
 586         spin_unlock_irqrestore(&mmu->lock, flags);
 587
 588         return status;
 589 }
 590
 591 /* -----------------------------------------------------------------------------
 592  * IOMMU Operations
 593  */
 594
 595 static struct iommu_domain *__ipmmu_domain_alloc(unsigned type)
 596 {
 597         struct ipmmu_vmsa_domain *domain;
 598
 599         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 600         if (!domain)
 601                 return NULL;
 602
 603         mutex_init(&domain->mutex);
 604
 605         return &domain->io_domain;
 606 }
 607
 608 static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
 609 {
 610         struct iommu_domain *io_domain = NULL;
 611
 612         switch (type) {
 613         case IOMMU_DOMAIN_UNMANAGED:
 614                 io_domain = __ipmmu_domain_alloc(type);
 615                 break;
 616
 617         case IOMMU_DOMAIN_DMA:
 618                 io_domain = __ipmmu_domain_alloc(type);
 619                 if (io_domain && iommu_get_dma_cookie(io_domain)) {
 620                         kfree(io_domain);
 621                         io_domain = NULL;
 622                 }
 623                 break;
 624         }
 625
 626         return io_domain;
 627 }
 628
 629 static void ipmmu_domain_free(struct iommu_domain *io_domain)
 630 {
 631         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 632
 633         /*
 634          * Free the domain resources. We assume that all devices have already
 635          * been detached.
 636          */
 637         iommu_put_dma_cookie(io_domain);
 638         ipmmu_domain_destroy_context(domain);
 639         free_io_pgtable_ops(domain->iop);
 640         kfree(domain);
 641 }
 642
 643 static int ipmmu_attach_device(struct iommu_domain *io_domain,
 644                                struct device *dev)
 645 {
 646         struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 647         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 648         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 649         unsigned int i;
 650         int ret = 0;
 651
 652         if (!mmu) {
 653                 dev_err(dev, "Cannot attach to IPMMU\n");
 654                 return -ENXIO;
 655         }
 656
 657         mutex_lock(&domain->mutex);
 658
 659         if (!domain->mmu) {
 660                 /* The domain hasn't been used yet, initialize it. */
 661                 domain->mmu = mmu;
 662                 ret = ipmmu_domain_init_context(domain);
 663                 if (ret < 0) {
 664                         dev_err(dev, "Unable to initialize IPMMU context\n");
 665                         domain->mmu = NULL;
 666                 } else {
 667                         dev_info(dev, "Using IPMMU context %u\n",
 668                                  domain->context_id);
 669                 }
 670         } else if (domain->mmu != mmu) {
 671                 /*
 672                  * Something is wrong, we can't attach two devices using
 673                  * different IOMMUs to the same domain.
 674                  */
 675                 dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
 676                         dev_name(mmu->dev), dev_name(domain->mmu->dev));
 677                 ret = -EINVAL;
 678         } else
 679                 dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
 680
 681         mutex_unlock(&domain->mutex);
 682
 683         if (ret < 0)
 684                 return ret;
 685
 686         for (i = 0; i < fwspec->num_ids; ++i)
 687                 ipmmu_utlb_enable(domain, fwspec->ids[i]);
 688
 689         return 0;
 690 }
 691
 692 static void ipmmu_detach_device(struct iommu_domain *io_domain,
 693                                 struct device *dev)
 694 {
 695         struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 696         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 697         unsigned int i;
 698
 699         for (i = 0; i < fwspec->num_ids; ++i)
 700                 ipmmu_utlb_disable(domain, fwspec->ids[i]);
 701
 702         /*
 703          * TODO: Optimize by disabling the context when no device is attached.
 704          */
 705 }
 706
 707 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
 708                      phys_addr_t paddr, size_t size, int prot)
 709 {
 710         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 711
 712         if (!domain)
 713                 return -ENODEV;
 714
 715         return domain->iop->map(domain->iop, iova, paddr, size, prot);
 716 }
 717
 718 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
 719                           size_t size)
 720 {
 721         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 722
 723         return domain->iop->unmap(domain->iop, iova, size);
 724 }
 725
 726 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain)
 727 {
 728         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 729
 730         if (domain->mmu)
 731                 ipmmu_tlb_flush_all(domain);
 732 }
 733
 734 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
 735                                       dma_addr_t iova)
 736 {
 737         struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 738
 739         /* TODO: Is locking needed ? */
 740
 741         return domain->iop->iova_to_phys(domain->iop, iova);
 742 }
 743
 744 static int ipmmu_init_platform_device(struct device *dev,
 745                                       struct of_phandle_args *args)
 746 {
 747         struct platform_device *ipmmu_pdev;
 748
 749         ipmmu_pdev = of_find_device_by_node(args->np);
 750         if (!ipmmu_pdev)
 751                 return -ENODEV;
 752
 753         dev->iommu_fwspec->iommu_priv = platform_get_drvdata(ipmmu_pdev);
 754         return 0;
 755 }
 756
 757 static bool ipmmu_slave_whitelist(struct device *dev)
 758 {
 759         /* By default, do not allow use of IPMMU */
 760         return false;
 761 }
 762
 763 static const struct soc_device_attribute soc_rcar_gen3[] = {
 764         { .soc_id = "r8a7795", },
 765         { .soc_id = "r8a7796", },
 766         { .soc_id = "r8a77965", },
 767         { .soc_id = "r8a77970", },
 768         { .soc_id = "r8a77995", },
 769         { /* sentinel */ }
 770 };
 771
 772 static int ipmmu_of_xlate(struct device *dev,
 773                           struct of_phandle_args *spec)
 774 {
 775         /* For R-Car Gen3 use a white list to opt-in slave devices */
 776         if (soc_device_match(soc_rcar_gen3) && !ipmmu_slave_whitelist(dev))
 777                 return -ENODEV;
 778
 779         iommu_fwspec_add_ids(dev, spec->args, 1);
 780
 781         /* Initialize once - xlate() will call multiple times */
 782         if (to_ipmmu(dev))
 783                 return 0;
 784
 785         return ipmmu_init_platform_device(dev, spec);
 786 }
 787
 788 static int ipmmu_init_arm_mapping(struct device *dev)
 789 {
 790         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 791         struct iommu_group *group;
 792         int ret;
 793
 794         /* Create a device group and add the device to it. */
 795         group = iommu_group_alloc();
 796         if (IS_ERR(group)) {
 797                 dev_err(dev, "Failed to allocate IOMMU group\n");
 798                 return PTR_ERR(group);
 799         }
 800
 801         ret = iommu_group_add_device(group, dev);
 802         iommu_group_put(group);
 803
 804         if (ret < 0) {
 805                 dev_err(dev, "Failed to add device to IPMMU group\n");
 806                 return ret;
 807         }
 808
 809         /*
 810          * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 811          * VAs. This will allocate a corresponding IOMMU domain.
 812          *
 813          * TODO:
 814          * - Create one mapping per context (TLB).
 815          * - Make the mapping size configurable ? We currently use a 2GB mapping
 816          *   at a 1GB offset to ensure that NULL VAs will fault.
 817          */
 818         if (!mmu->mapping) {
 819                 struct dma_iommu_mapping *mapping;
 820
 821                 mapping = arm_iommu_create_mapping(&platform_bus_type,
 822                                                    SZ_1G, SZ_2G);
 823                 if (IS_ERR(mapping)) {
 824                         dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 825                         ret = PTR_ERR(mapping);
 826                         goto error;
 827                 }
 828
 829                 mmu->mapping = mapping;
 830         }
 831
 832         /* Attach the ARM VA mapping to the device. */
 833         ret = arm_iommu_attach_device(dev, mmu->mapping);
 834         if (ret < 0) {
 835                 dev_err(dev, "Failed to attach device to VA mapping\n");
 836                 goto error;
 837         }
 838
 839         return 0;
 840
 841 error:
 842         iommu_group_remove_device(dev);
 843         if (mmu->mapping)
 844                 arm_iommu_release_mapping(mmu->mapping);
 845
 846         return ret;
 847 }
 848
 849 static int ipmmu_add_device(struct device *dev)
 850 {
 851         struct iommu_group *group;
 852
 853         /*
 854          * Only let through devices that have been verified in xlate()
 855          */
 856         if (!to_ipmmu(dev))
 857                 return -ENODEV;
 858
 859         if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
 860                 return ipmmu_init_arm_mapping(dev);
 861
 862         group = iommu_group_get_for_dev(dev);
 863         if (IS_ERR(group))
 864                 return PTR_ERR(group);
 865
 866         iommu_group_put(group);
 867         return 0;
 868 }
 869
 870 static void ipmmu_remove_device(struct device *dev)
 871 {
 872         arm_iommu_detach_device(dev);
 873         iommu_group_remove_device(dev);
 874 }
 875
 876 static struct iommu_group *ipmmu_find_group(struct device *dev)
 877 {
 878         struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
 879         struct iommu_group *group;
 880
 881         if (mmu->group)
 882                 return iommu_group_ref_get(mmu->group);
 883
 884         group = iommu_group_alloc();
 885         if (!IS_ERR(group))
 886                 mmu->group = group;
 887
 888         return group;
 889 }
 890
 891 static const struct iommu_ops ipmmu_ops = {
 892         .domain_alloc = ipmmu_domain_alloc,
 893         .domain_free = ipmmu_domain_free,
 894         .attach_dev = ipmmu_attach_device,
 895         .detach_dev = ipmmu_detach_device,
 896         .map = ipmmu_map,
 897         .unmap = ipmmu_unmap,
 898         .flush_iotlb_all = ipmmu_iotlb_sync,
 899         .iotlb_sync = ipmmu_iotlb_sync,
 900         .iova_to_phys = ipmmu_iova_to_phys,
 901         .add_device = ipmmu_add_device,
 902         .remove_device = ipmmu_remove_device,
 903         .device_group = ipmmu_find_group,
 904         .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
 905         .of_xlate = ipmmu_of_xlate,
 906 };
 907
 908 /* -----------------------------------------------------------------------------
 909  * Probe/remove and init
 910  */
 911
 912 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
 913 {
 914         unsigned int i;
 915
 916         /* Disable all contexts. */
 917         for (i = 0; i < mmu->num_ctx; ++i)
 918                 ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
 919 }
 920
 921 static const struct ipmmu_features ipmmu_features_default = {
 922         .use_ns_alias_offset = true,
 923         .has_cache_leaf_nodes = false,
 924         .number_of_contexts = 1, /* software only tested with one context */
 925         .setup_imbuscr = true,
 926         .twobit_imttbcr_sl0 = false,
 927         .reserved_context = false,
 928 };
 929
 930 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
 931         .use_ns_alias_offset = false,
 932         .has_cache_leaf_nodes = true,
 933         .number_of_contexts = 8,
 934         .setup_imbuscr = false,
 935         .twobit_imttbcr_sl0 = true,
 936         .reserved_context = true,
 937 };
 938
 939 static const struct of_device_id ipmmu_of_ids[] = {
 940         {
 941                 .compatible = "renesas,ipmmu-vmsa",
 942                 .data = &ipmmu_features_default,
 943         }, {
 944                 .compatible = "renesas,ipmmu-r8a7795",
 945                 .data = &ipmmu_features_rcar_gen3,
 946         }, {
 947                 .compatible = "renesas,ipmmu-r8a7796",
 948                 .data = &ipmmu_features_rcar_gen3,
 949         }, {
 950                 .compatible = "renesas,ipmmu-r8a77965",
 951                 .data = &ipmmu_features_rcar_gen3,
 952         }, {
 953                 .compatible = "renesas,ipmmu-r8a77970",
 954                 .data = &ipmmu_features_rcar_gen3,
 955         }, {
 956                 .compatible = "renesas,ipmmu-r8a77995",
 957                 .data = &ipmmu_features_rcar_gen3,
 958         }, {
 959                 /* Terminator */
 960         },
 961 };
 962
 963 MODULE_DEVICE_TABLE(of, ipmmu_of_ids);
 964
 965 static int ipmmu_probe(struct platform_device *pdev)
 966 {
 967         struct ipmmu_vmsa_device *mmu;
 968         struct resource *res;
 969         int irq;
 970         int ret;
 971
 972         mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
 973         if (!mmu) {
 974                 dev_err(&pdev->dev, "cannot allocate device data\n");
 975                 return -ENOMEM;
 976         }
 977
 978         mmu->dev = &pdev->dev;
 979         mmu->num_utlbs = 48;
 980         spin_lock_init(&mmu->lock);
 981         bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
 982         mmu->features = of_device_get_match_data(&pdev->dev);
 983         dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
 984
 985         /* Map I/O memory and request IRQ. */
 986         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 987         mmu->base = devm_ioremap_resource(&pdev->dev, res);
 988         if (IS_ERR(mmu->base))
 989                 return PTR_ERR(mmu->base);
 990
 991         /*
 992          * The IPMMU has two register banks, for secure and non-secure modes.
 993          * The bank mapped at the beginning of the IPMMU address space
 994          * corresponds to the running mode of the CPU. When running in secure
 995          * mode the non-secure register bank is also available at an offset.
 996          *
 997          * Secure mode operation isn't clearly documented and is thus currently
 998          * not implemented in the driver. Furthermore, preliminary tests of
 999          * non-secure operation with the main register bank were not successful.
1000          * Offset the registers base unconditionally to point to the non-secure
1001          * alias space for now.
1002          */
1003         if (mmu->features->use_ns_alias_offset)
1004                 mmu->base += IM_NS_ALIAS_OFFSET;
1005
1006         mmu->num_ctx = min_t(unsigned int, IPMMU_CTX_MAX,
1007                              mmu->features->number_of_contexts);
1008
1009         irq = platform_get_irq(pdev, 0);
1010
1011         /*
1012          * Determine if this IPMMU instance is a root device by checking for
1013          * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1014          */
1015         if (!mmu->features->has_cache_leaf_nodes ||
1016             !of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
1017                 mmu->root = mmu;
1018         else
1019                 mmu->root = ipmmu_find_root();
1020
1021         /*
1022          * Wait until the root device has been registered for sure.
1023          */
1024         if (!mmu->root)
1025                 return -EPROBE_DEFER;
1026
1027         /* Root devices have mandatory IRQs */
1028         if (ipmmu_is_root(mmu)) {
1029                 if (irq < 0) {
1030                         dev_err(&pdev->dev, "no IRQ found\n");
1031                         return irq;
1032                 }
1033
1034                 ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1035                                        dev_name(&pdev->dev), mmu);
1036                 if (ret < 0) {
1037                         dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1038                         return ret;
1039                 }
1040
1041                 ipmmu_device_reset(mmu);
1042
1043                 if (mmu->features->reserved_context) {
1044                         dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1045                         set_bit(0, mmu->ctx);
1046                 }
1047         }
1048
1049         /*
1050          * Register the IPMMU to the IOMMU subsystem in the following cases:
1051          * - R-Car Gen2 IPMMU (all devices registered)
1052          * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1053          */
1054         if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1055                 ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1056                                              dev_name(&pdev->dev));
1057                 if (ret)
1058                         return ret;
1059
1060                 iommu_device_set_ops(&mmu->iommu, &ipmmu_ops);
1061                 iommu_device_set_fwnode(&mmu->iommu,
1062                                         &pdev->dev.of_node->fwnode);
1063
1064                 ret = iommu_device_register(&mmu->iommu);
1065                 if (ret)
1066                         return ret;
1067
1068 #if defined(CONFIG_IOMMU_DMA)
1069                 if (!iommu_present(&platform_bus_type))
1070                         bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1071 #endif
1072         }
1073
1074         /*
1075          * We can't create the ARM mapping here as it requires the bus to have
1076          * an IOMMU, which only happens when bus_set_iommu() is called in
1077          * ipmmu_init() after the probe function returns.
1078          */
1079
1080         platform_set_drvdata(pdev, mmu);
1081
1082         return 0;
1083 }
1084
1085 static int ipmmu_remove(struct platform_device *pdev)
1086 {
1087         struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1088
1089         iommu_device_sysfs_remove(&mmu->iommu);
1090         iommu_device_unregister(&mmu->iommu);
1091
1092         arm_iommu_release_mapping(mmu->mapping);
1093
1094         ipmmu_device_reset(mmu);
1095
1096         return 0;
1097 }
1098
1099 static struct platform_driver ipmmu_driver = {
1100         .driver = {
1101                 .name = "ipmmu-vmsa",
1102                 .of_match_table = of_match_ptr(ipmmu_of_ids),
1103         },
1104         .probe = ipmmu_probe,
1105         .remove = ipmmu_remove,
1106 };
1107
1108 static int __init ipmmu_init(void)
1109 {
1110         struct device_node *np;
1111         static bool setup_done;
1112         int ret;
1113
1114         if (setup_done)
1115                 return 0;
1116
1117         np = of_find_matching_node(NULL, ipmmu_of_ids);
1118         if (!np)
1119                 return 0;
1120
1121         of_node_put(np);
1122
1123         ret = platform_driver_register(&ipmmu_driver);
1124         if (ret < 0)
1125                 return ret;
1126
1127 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
1128         if (!iommu_present(&platform_bus_type))
1129                 bus_set_iommu(&platform_bus_type, &ipmmu_ops);
1130 #endif
1131
1132         setup_done = true;
1133         return 0;
1134 }
1135
1136 static void __exit ipmmu_exit(void)
1137 {
1138         return platform_driver_unregister(&ipmmu_driver);
1139 }
1140
1141 subsys_initcall(ipmmu_init);
1142 module_exit(ipmmu_exit);
1143
1144 MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
1145 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
1146 MODULE_LICENSE("GPL v2");