include/linux/iommu.h

   1 /*
   2  * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
   3  * Author: Joerg Roedel <joerg.roedel@amd.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published
   7  * by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  */
  18
  19 #ifndef __LINUX_IOMMU_H
  20 #define __LINUX_IOMMU_H
  21
  22 #include <linux/errno.h>
  23 #include <linux/err.h>
  24 #include <linux/of.h>
  25 #include <linux/types.h>
  26 #include <linux/scatterlist.h>
  27 #include <trace/events/iommu.h>
  28
  29 #define IOMMU_READ      (1 << 0)
  30 #define IOMMU_WRITE     (1 << 1)
  31 #define IOMMU_CACHE     (1 << 2) /* DMA cache coherency */
  32 #define IOMMU_NOEXEC    (1 << 3)
  33 #define IOMMU_MMIO      (1 << 4) /* e.g. things like MSI doorbells */
  34 /*
  35  * This is to make the IOMMU API setup privileged
  36  * mapppings accessible by the master only at higher
  37  * privileged execution level and inaccessible at
  38  * less privileged levels.
  39  */
  40 #define IOMMU_PRIV      (1 << 5)
  41
  42 struct iommu_ops;
  43 struct iommu_group;
  44 struct bus_type;
  45 struct device;
  46 struct iommu_domain;
  47 struct notifier_block;
  48
  49 /* iommu fault flags */
  50 #define IOMMU_FAULT_READ        0x0
  51 #define IOMMU_FAULT_WRITE       0x1
  52
  53 typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
  54                         struct device *, unsigned long, int, void *);
  55
  56 struct iommu_domain_geometry {
  57         dma_addr_t aperture_start; /* First address that can be mapped    */
  58         dma_addr_t aperture_end;   /* Last address that can be mapped     */
  59         bool force_aperture;       /* DMA only allowed in mappable range? */
  60 };
  61
  62 /* Domain feature flags */
  63 #define __IOMMU_DOMAIN_PAGING   (1U << 0)  /* Support for iommu_map/unmap */
  64 #define __IOMMU_DOMAIN_DMA_API  (1U << 1)  /* Domain for use in DMA-API
  65                                               implementation              */
  66 #define __IOMMU_DOMAIN_PT       (1U << 2)  /* Domain is identity mapped   */
  67
  68 /*
  69  * This are the possible domain-types
  70  *
  71  *      IOMMU_DOMAIN_BLOCKED    - All DMA is blocked, can be used to isolate
  72  *                                devices
  73  *      IOMMU_DOMAIN_IDENTITY   - DMA addresses are system physical addresses
  74  *      IOMMU_DOMAIN_UNMANAGED  - DMA mappings managed by IOMMU-API user, used
  75  *                                for VMs
  76  *      IOMMU_DOMAIN_DMA        - Internally used for DMA-API implementations.
  77  *                                This flag allows IOMMU drivers to implement
  78  *                                certain optimizations for these domains
  79  */
  80 #define IOMMU_DOMAIN_BLOCKED    (0U)
  81 #define IOMMU_DOMAIN_IDENTITY   (__IOMMU_DOMAIN_PT)
  82 #define IOMMU_DOMAIN_UNMANAGED  (__IOMMU_DOMAIN_PAGING)
  83 #define IOMMU_DOMAIN_DMA        (__IOMMU_DOMAIN_PAGING |        \
  84                                  __IOMMU_DOMAIN_DMA_API)
  85
  86 struct iommu_domain {
  87         unsigned type;
  88         const struct iommu_ops *ops;
  89         unsigned long pgsize_bitmap;    /* Bitmap of page sizes in use */
  90         iommu_fault_handler_t handler;
  91         void *handler_token;
  92         struct iommu_domain_geometry geometry;
  93         void *iova_cookie;
  94 };
  95
  96 enum iommu_cap {
  97         IOMMU_CAP_CACHE_COHERENCY,      /* IOMMU can enforce cache coherent DMA
  98                                            transactions */
  99         IOMMU_CAP_INTR_REMAP,           /* IOMMU supports interrupt isolation */
 100         IOMMU_CAP_NOEXEC,               /* IOMMU_NOEXEC flag */
 101 };
 102
 103 /*
 104  * Following constraints are specifc to FSL_PAMUV1:
 105  *  -aperture must be power of 2, and naturally aligned
 106  *  -number of windows must be power of 2, and address space size
 107  *   of each window is determined by aperture size / # of windows
 108  *  -the actual size of the mapped region of a window must be power
 109  *   of 2 starting with 4KB and physical address must be naturally
 110  *   aligned.
 111  * DOMAIN_ATTR_FSL_PAMUV1 corresponds to the above mentioned contraints.
 112  * The caller can invoke iommu_domain_get_attr to check if the underlying
 113  * iommu implementation supports these constraints.
 114  */
 115
 116 enum iommu_attr {
 117         DOMAIN_ATTR_GEOMETRY,
 118         DOMAIN_ATTR_PAGING,
 119         DOMAIN_ATTR_WINDOWS,
 120         DOMAIN_ATTR_FSL_PAMU_STASH,
 121         DOMAIN_ATTR_FSL_PAMU_ENABLE,
 122         DOMAIN_ATTR_FSL_PAMUV1,
 123         DOMAIN_ATTR_NESTING,    /* two stages of translation */
 124         DOMAIN_ATTR_MAX,
 125 };
 126
 127 /**
 128  * struct iommu_dm_region - descriptor for a direct mapped memory region
 129  * @list: Linked list pointers
 130  * @start: System physical start address of the region
 131  * @length: Length of the region in bytes
 132  * @prot: IOMMU Protection flags (READ/WRITE/...)
 133  */
 134 struct iommu_dm_region {
 135         struct list_head        list;
 136         phys_addr_t             start;
 137         size_t                  length;
 138         int                     prot;
 139 };
 140
 141 #ifdef CONFIG_IOMMU_API
 142
 143 /**
 144  * struct iommu_ops - iommu ops and capabilities
 145  * @capable: check capability
 146  * @domain_alloc: allocate iommu domain
 147  * @domain_free: free iommu domain
 148  * @attach_dev: attach device to an iommu domain
 149  * @detach_dev: detach device from an iommu domain
 150  * @map: map a physically contiguous memory region to an iommu domain
 151  * @unmap: unmap a physically contiguous memory region from an iommu domain
 152  * @map_sg: map a scatter-gather list of physically contiguous memory chunks
 153  * to an iommu domain
 154  * @iova_to_phys: translate iova to physical address
 155  * @add_device: add device to iommu grouping
 156  * @remove_device: remove device from iommu grouping
 157  * @device_group: find iommu group for a particular device
 158  * @domain_get_attr: Query domain attributes
 159  * @domain_set_attr: Change domain attributes
 160  * @get_dm_regions: Request list of direct mapping requirements for a device
 161  * @put_dm_regions: Free list of direct mapping requirements for a device
 162  * @apply_dm_region: Temporary helper call-back for iova reserved ranges
 163  * @domain_window_enable: Configure and enable a particular window for a domain
 164  * @domain_window_disable: Disable a particular window for a domain
 165  * @domain_set_windows: Set the number of windows for a domain
 166  * @domain_get_windows: Return the number of windows for a domain
 167  * @of_xlate: add OF master IDs to iommu grouping
 168  * @pgsize_bitmap: bitmap of all possible supported page sizes
 169  */
 170 struct iommu_ops {
 171         bool (*capable)(enum iommu_cap);
 172
 173         /* Domain allocation and freeing by the iommu driver */
 174         struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type);
 175         void (*domain_free)(struct iommu_domain *);
 176
 177         int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
 178         void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
 179         int (*map)(struct iommu_domain *domain, unsigned long iova,
 180                    phys_addr_t paddr, size_t size, int prot);
 181         size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
 182                      size_t size);
 183         size_t (*map_sg)(struct iommu_domain *domain, unsigned long iova,
 184                          struct scatterlist *sg, unsigned int nents, int prot);
 185         phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t iova);
 186         int (*add_device)(struct device *dev);
 187         void (*remove_device)(struct device *dev);
 188         struct iommu_group *(*device_group)(struct device *dev);
 189         int (*domain_get_attr)(struct iommu_domain *domain,
 190                                enum iommu_attr attr, void *data);
 191         int (*domain_set_attr)(struct iommu_domain *domain,
 192                                enum iommu_attr attr, void *data);
 193
 194         /* Request/Free a list of direct mapping requirements for a device */
 195         void (*get_dm_regions)(struct device *dev, struct list_head *list);
 196         void (*put_dm_regions)(struct device *dev, struct list_head *list);
 197         void (*apply_dm_region)(struct device *dev, struct iommu_domain *domain,
 198                                 struct iommu_dm_region *region);
 199
 200         /* Window handling functions */
 201         int (*domain_window_enable)(struct iommu_domain *domain, u32 wnd_nr,
 202                                     phys_addr_t paddr, u64 size, int prot);
 203         void (*domain_window_disable)(struct iommu_domain *domain, u32 wnd_nr);
 204         /* Set the number of windows per domain */
 205         int (*domain_set_windows)(struct iommu_domain *domain, u32 w_count);
 206         /* Get the number of windows per domain */
 207         u32 (*domain_get_windows)(struct iommu_domain *domain);
 208
 209         int (*of_xlate)(struct device *dev, struct of_phandle_args *args);
 210
 211         unsigned long pgsize_bitmap;
 212 };
 213
 214 #define IOMMU_GROUP_NOTIFY_ADD_DEVICE           1 /* Device added */
 215 #define IOMMU_GROUP_NOTIFY_DEL_DEVICE           2 /* Pre Device removed */
 216 #define IOMMU_GROUP_NOTIFY_BIND_DRIVER          3 /* Pre Driver bind */
 217 #define IOMMU_GROUP_NOTIFY_BOUND_DRIVER         4 /* Post Driver bind */
 218 #define IOMMU_GROUP_NOTIFY_UNBIND_DRIVER        5 /* Pre Driver unbind */
 219 #define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER       6 /* Post Driver unbind */
 220
 221 extern int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops);
 222 extern bool iommu_present(struct bus_type *bus);
 223 extern bool iommu_capable(struct bus_type *bus, enum iommu_cap cap);
 224 extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
 225 extern struct iommu_group *iommu_group_get_by_id(int id);
 226 extern void iommu_domain_free(struct iommu_domain *domain);
 227 extern int iommu_attach_device(struct iommu_domain *domain,
 228                                struct device *dev);
 229 extern void iommu_detach_device(struct iommu_domain *domain,
 230                                 struct device *dev);
 231 extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
 232 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
 233                      phys_addr_t paddr, size_t size, int prot);
 234 extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 235                        size_t size);
 236 extern size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 237                                 struct scatterlist *sg,unsigned int nents,
 238                                 int prot);
 239 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova);
 240 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 241                         iommu_fault_handler_t handler, void *token);
 242
 243 extern void iommu_get_dm_regions(struct device *dev, struct list_head *list);
 244 extern void iommu_put_dm_regions(struct device *dev, struct list_head *list);
 245 extern int iommu_request_dm_for_dev(struct device *dev);
 246
 247 extern int iommu_attach_group(struct iommu_domain *domain,
 248                               struct iommu_group *group);
 249 extern void iommu_detach_group(struct iommu_domain *domain,
 250                                struct iommu_group *group);
 251 extern struct iommu_group *iommu_group_alloc(void);
 252 extern void *iommu_group_get_iommudata(struct iommu_group *group);
 253 extern void iommu_group_set_iommudata(struct iommu_group *group,
 254                                       void *iommu_data,
 255                                       void (*release)(void *iommu_data));
 256 extern int iommu_group_set_name(struct iommu_group *group, const char *name);
 257 extern int iommu_group_add_device(struct iommu_group *group,
 258                                   struct device *dev);
 259 extern void iommu_group_remove_device(struct device *dev);
 260 extern int iommu_group_for_each_dev(struct iommu_group *group, void *data,
 261                                     int (*fn)(struct device *, void *));
 262 extern struct iommu_group *iommu_group_get(struct device *dev);
 263 extern struct iommu_group *iommu_group_ref_get(struct iommu_group *group);
 264 extern void iommu_group_put(struct iommu_group *group);
 265 extern int iommu_group_register_notifier(struct iommu_group *group,
 266                                          struct notifier_block *nb);
 267 extern int iommu_group_unregister_notifier(struct iommu_group *group,
 268                                            struct notifier_block *nb);
 269 extern int iommu_group_id(struct iommu_group *group);
 270 extern struct iommu_group *iommu_group_get_for_dev(struct device *dev);
 271 extern struct iommu_domain *iommu_group_default_domain(struct iommu_group *);
 272
 273 extern int iommu_domain_get_attr(struct iommu_domain *domain, enum iommu_attr,
 274                                  void *data);
 275 extern int iommu_domain_set_attr(struct iommu_domain *domain, enum iommu_attr,
 276                                  void *data);
 277 struct device *iommu_device_create(struct device *parent, void *drvdata,
 278                                    const struct attribute_group **groups,
 279                                    const char *fmt, ...) __printf(4, 5);
 280 void iommu_device_destroy(struct device *dev);
 281 int iommu_device_link(struct device *dev, struct device *link);
 282 void iommu_device_unlink(struct device *dev, struct device *link);
 283
 284 /* Window handling function prototypes */
 285 extern int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr,
 286                                       phys_addr_t offset, u64 size,
 287                                       int prot);
 288 extern void iommu_domain_window_disable(struct iommu_domain *domain, u32 wnd_nr);
 289 /**
 290  * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
 291  * @domain: the iommu domain where the fault has happened
 292  * @dev: the device where the fault has happened
 293  * @iova: the faulting address
 294  * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
 295  *
 296  * This function should be called by the low-level IOMMU implementations
 297  * whenever IOMMU faults happen, to allow high-level users, that are
 298  * interested in such events, to know about them.
 299  *
 300  * This event may be useful for several possible use cases:
 301  * - mere logging of the event
 302  * - dynamic TLB/PTE loading
 303  * - if restarting of the faulting device is required
 304  *
 305  * Returns 0 on success and an appropriate error code otherwise (if dynamic
 306  * PTE/TLB loading will one day be supported, implementations will be able
 307  * to tell whether it succeeded or not according to this return value).
 308  *
 309  * Specifically, -ENOSYS is returned if a fault handler isn't installed
 310  * (though fault handlers can also return -ENOSYS, in case they want to
 311  * elicit the default behavior of the IOMMU drivers).
 312  */
 313 static inline int report_iommu_fault(struct iommu_domain *domain,
 314                 struct device *dev, unsigned long iova, int flags)
 315 {
 316         int ret = -ENOSYS;
 317
 318         /*
 319          * if upper layers showed interest and installed a fault handler,
 320          * invoke it.
 321          */
 322         if (domain->handler)
 323                 ret = domain->handler(domain, dev, iova, flags,
 324                                                 domain->handler_token);
 325
 326         trace_io_page_fault(dev, iova, flags);
 327         return ret;
 328 }
 329
 330 static inline size_t iommu_map_sg(struct iommu_domain *domain,
 331                                   unsigned long iova, struct scatterlist *sg,
 332                                   unsigned int nents, int prot)
 333 {
 334         return domain->ops->map_sg(domain, iova, sg, nents, prot);
 335 }
 336
 337 /* PCI device grouping function */
 338 extern struct iommu_group *pci_device_group(struct device *dev);
 339 /* Generic device grouping function */
 340 extern struct iommu_group *generic_device_group(struct device *dev);
 341
 342 /**
 343  * struct iommu_fwspec - per-device IOMMU instance data
 344  * @ops: ops for this device's IOMMU
 345  * @iommu_fwnode: firmware handle for this device's IOMMU
 346  * @iommu_priv: IOMMU driver private data for this device
 347  * @num_ids: number of associated device IDs
 348  * @ids: IDs which this device may present to the IOMMU
 349  */
 350 struct iommu_fwspec {
 351         const struct iommu_ops  *ops;
 352         struct fwnode_handle    *iommu_fwnode;
 353         void                    *iommu_priv;
 354         unsigned int            num_ids;
 355         u32                     ids[1];
 356 };
 357
 358 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
 359                       const struct iommu_ops *ops);
 360 void iommu_fwspec_free(struct device *dev);
 361 int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids);
 362 void iommu_register_instance(struct fwnode_handle *fwnode,
 363                              const struct iommu_ops *ops);
 364 const struct iommu_ops *iommu_get_instance(struct fwnode_handle *fwnode);
 365
 366 #else /* CONFIG_IOMMU_API */
 367
 368 struct iommu_ops {};
 369 struct iommu_group {};
 370 struct iommu_fwspec {};
 371
 372 static inline bool iommu_present(struct bus_type *bus)
 373 {
 374         return false;
 375 }
 376
 377 static inline bool iommu_capable(struct bus_type *bus, enum iommu_cap cap)
 378 {
 379         return false;
 380 }
 381
 382 static inline struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
 383 {
 384         return NULL;
 385 }
 386
 387 static inline struct iommu_group *iommu_group_get_by_id(int id)
 388 {
 389         return NULL;
 390 }
 391
 392 static inline void iommu_domain_free(struct iommu_domain *domain)
 393 {
 394 }
 395
 396 static inline int iommu_attach_device(struct iommu_domain *domain,
 397                                       struct device *dev)
 398 {
 399         return -ENODEV;
 400 }
 401
 402 static inline void iommu_detach_device(struct iommu_domain *domain,
 403                                        struct device *dev)
 404 {
 405 }
 406
 407 static inline struct iommu_domain *iommu_get_domain_for_dev(struct device *dev)
 408 {
 409         return NULL;
 410 }
 411
 412 static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
 413                             phys_addr_t paddr, int gfp_order, int prot)
 414 {
 415         return -ENODEV;
 416 }
 417
 418 static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 419                               int gfp_order)
 420 {
 421         return -ENODEV;
 422 }
 423
 424 static inline size_t iommu_map_sg(struct iommu_domain *domain,
 425                                   unsigned long iova, struct scatterlist *sg,
 426                                   unsigned int nents, int prot)
 427 {
 428         return -ENODEV;
 429 }
 430
 431 static inline int iommu_domain_window_enable(struct iommu_domain *domain,
 432                                              u32 wnd_nr, phys_addr_t paddr,
 433                                              u64 size, int prot)
 434 {
 435         return -ENODEV;
 436 }
 437
 438 static inline void iommu_domain_window_disable(struct iommu_domain *domain,
 439                                                u32 wnd_nr)
 440 {
 441 }
 442
 443 static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
 444 {
 445         return 0;
 446 }
 447
 448 static inline void iommu_set_fault_handler(struct iommu_domain *domain,
 449                                 iommu_fault_handler_t handler, void *token)
 450 {
 451 }
 452
 453 static inline void iommu_get_dm_regions(struct device *dev,
 454                                         struct list_head *list)
 455 {
 456 }
 457
 458 static inline void iommu_put_dm_regions(struct device *dev,
 459                                         struct list_head *list)
 460 {
 461 }
 462
 463 static inline int iommu_request_dm_for_dev(struct device *dev)
 464 {
 465         return -ENODEV;
 466 }
 467
 468 static inline int iommu_attach_group(struct iommu_domain *domain,
 469                                      struct iommu_group *group)
 470 {
 471         return -ENODEV;
 472 }
 473
 474 static inline void iommu_detach_group(struct iommu_domain *domain,
 475                                       struct iommu_group *group)
 476 {
 477 }
 478
 479 static inline struct iommu_group *iommu_group_alloc(void)
 480 {
 481         return ERR_PTR(-ENODEV);
 482 }
 483
 484 static inline void *iommu_group_get_iommudata(struct iommu_group *group)
 485 {
 486         return NULL;
 487 }
 488
 489 static inline void iommu_group_set_iommudata(struct iommu_group *group,
 490                                              void *iommu_data,
 491                                              void (*release)(void *iommu_data))
 492 {
 493 }
 494
 495 static inline int iommu_group_set_name(struct iommu_group *group,
 496                                        const char *name)
 497 {
 498         return -ENODEV;
 499 }
 500
 501 static inline int iommu_group_add_device(struct iommu_group *group,
 502                                          struct device *dev)
 503 {
 504         return -ENODEV;
 505 }
 506
 507 static inline void iommu_group_remove_device(struct device *dev)
 508 {
 509 }
 510
 511 static inline int iommu_group_for_each_dev(struct iommu_group *group,
 512                                            void *data,
 513                                            int (*fn)(struct device *, void *))
 514 {
 515         return -ENODEV;
 516 }
 517
 518 static inline struct iommu_group *iommu_group_get(struct device *dev)
 519 {
 520         return NULL;
 521 }
 522
 523 static inline void iommu_group_put(struct iommu_group *group)
 524 {
 525 }
 526
 527 static inline int iommu_group_register_notifier(struct iommu_group *group,
 528                                                 struct notifier_block *nb)
 529 {
 530         return -ENODEV;
 531 }
 532
 533 static inline int iommu_group_unregister_notifier(struct iommu_group *group,
 534                                                   struct notifier_block *nb)
 535 {
 536         return 0;
 537 }
 538
 539 static inline int iommu_group_id(struct iommu_group *group)
 540 {
 541         return -ENODEV;
 542 }
 543
 544 static inline int iommu_domain_get_attr(struct iommu_domain *domain,
 545                                         enum iommu_attr attr, void *data)
 546 {
 547         return -EINVAL;
 548 }
 549
 550 static inline int iommu_domain_set_attr(struct iommu_domain *domain,
 551                                         enum iommu_attr attr, void *data)
 552 {
 553         return -EINVAL;
 554 }
 555
 556 static inline struct device *iommu_device_create(struct device *parent,
 557                                         void *drvdata,
 558                                         const struct attribute_group **groups,
 559                                         const char *fmt, ...)
 560 {
 561         return ERR_PTR(-ENODEV);
 562 }
 563
 564 static inline void iommu_device_destroy(struct device *dev)
 565 {
 566 }
 567
 568 static inline int iommu_device_link(struct device *dev, struct device *link)
 569 {
 570         return -EINVAL;
 571 }
 572
 573 static inline void iommu_device_unlink(struct device *dev, struct device *link)
 574 {
 575 }
 576
 577 static inline int iommu_fwspec_init(struct device *dev,
 578                                     struct fwnode_handle *iommu_fwnode,
 579                                     const struct iommu_ops *ops)
 580 {
 581         return -ENODEV;
 582 }
 583
 584 static inline void iommu_fwspec_free(struct device *dev)
 585 {
 586 }
 587
 588 static inline int iommu_fwspec_add_ids(struct device *dev, u32 *ids,
 589                                        int num_ids)
 590 {
 591         return -ENODEV;
 592 }
 593
 594 static inline void iommu_register_instance(struct fwnode_handle *fwnode,
 595                                            const struct iommu_ops *ops)
 596 {
 597 }
 598
 599 static inline
 600 const struct iommu_ops *iommu_get_instance(struct fwnode_handle *fwnode)
 601 {
 602         return NULL;
 603 }
 604
 605 #endif /* CONFIG_IOMMU_API */
 606
 607 #endif /* __LINUX_IOMMU_H */