drivers/iommu/iommu.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
iommu_set_cmd_line_dma_api
iommu_cmd_line_dma_api
iommu_domain_type_str
iommu_subsys_init
iommu_device_register
iommu_device_unregister
iommu_get_dev_param
iommu_free_dev_param
iommu_probe_device
iommu_release_device
iommu_set_def_domain_type
iommu_dma_setup
iommu_group_attr_show
iommu_group_attr_store
iommu_group_create_file
iommu_group_remove_file
iommu_group_show_name
iommu_insert_resv_region
iommu_insert_device_resv_regions
iommu_get_group_resv_regions
iommu_group_show_resv_regions
iommu_group_show_type
iommu_group_release
iommu_group_alloc
iommu_group_get_by_id
iommu_group_get_iommudata
iommu_group_set_iommudata
iommu_group_set_name
iommu_group_create_direct_mappings
iommu_group_add_device
iommu_group_remove_device
iommu_group_device_count
__iommu_group_for_each_dev
iommu_group_for_each_dev
iommu_group_get
iommu_group_ref_get
iommu_group_put
iommu_group_register_notifier
iommu_group_unregister_notifier
iommu_register_device_fault_handler
iommu_unregister_device_fault_handler
iommu_report_device_fault
iommu_page_response
iommu_group_id
get_pci_function_alias_group
get_pci_alias_group
get_pci_alias_or_group
generic_device_group
pci_device_group
fsl_mc_device_group
iommu_group_get_for_dev
iommu_group_default_domain
add_iommu_group
remove_iommu_group
iommu_bus_notifier
iommu_bus_init
bus_set_iommu
iommu_present
iommu_capable
iommu_set_fault_handler
__iommu_domain_alloc
iommu_domain_alloc
iommu_domain_free
__iommu_attach_device
iommu_attach_device
__iommu_detach_device
iommu_detach_device
iommu_get_domain_for_dev
iommu_get_dma_domain
iommu_group_do_attach_device
__iommu_attach_group
iommu_attach_group
iommu_group_do_detach_device
__iommu_detach_group
iommu_detach_group
iommu_iova_to_phys
iommu_pgsize
iommu_map
__iommu_unmap
iommu_unmap
iommu_unmap_fast
iommu_map_sg
iommu_domain_window_enable
iommu_domain_window_disable
report_iommu_fault
iommu_init
iommu_domain_get_attr
iommu_domain_set_attr
iommu_get_resv_regions
iommu_put_resv_regions
iommu_alloc_resv_region
request_default_domain_for_dev
iommu_request_dm_for_dev
iommu_request_dma_domain_for_dev
iommu_set_default_passthrough
iommu_set_default_translated
iommu_default_passthrough
iommu_ops_from_fwnode
iommu_fwspec_init
iommu_fwspec_free
iommu_fwspec_add_ids
iommu_dev_has_feature
iommu_dev_enable_feature
iommu_dev_disable_feature
iommu_dev_feature_enabled
iommu_aux_attach_device
iommu_aux_detach_device
iommu_aux_get_pasid
iommu_sva_bind_device
iommu_sva_unbind_device
iommu_sva_set_ops
iommu_sva_get_pasid
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
   4  * Author: Joerg Roedel <jroedel@suse.de>
   5  */
   6 
   7 #define pr_fmt(fmt)    "iommu: " fmt
   8 
   9 #include <linux/device.h>
  10 #include <linux/kernel.h>
  11 #include <linux/bug.h>
  12 #include <linux/types.h>
  13 #include <linux/init.h>
  14 #include <linux/export.h>
  15 #include <linux/slab.h>
  16 #include <linux/errno.h>
  17 #include <linux/iommu.h>
  18 #include <linux/idr.h>
  19 #include <linux/notifier.h>
  20 #include <linux/err.h>
  21 #include <linux/pci.h>
  22 #include <linux/bitops.h>
  23 #include <linux/property.h>
  24 #include <linux/fsl/mc.h>
  25 #include <trace/events/iommu.h>
  26 
  27 static struct kset *iommu_group_kset;
  28 static DEFINE_IDA(iommu_group_ida);
  29 
  30 static unsigned int iommu_def_domain_type __read_mostly;
  31 static bool iommu_dma_strict __read_mostly = true;
  32 static u32 iommu_cmd_line __read_mostly;
  33 
  34 struct iommu_group {
  35         struct kobject kobj;
  36         struct kobject *devices_kobj;
  37         struct list_head devices;
  38         struct mutex mutex;
  39         struct blocking_notifier_head notifier;
  40         void *iommu_data;
  41         void (*iommu_data_release)(void *iommu_data);
  42         char *name;
  43         int id;
  44         struct iommu_domain *default_domain;
  45         struct iommu_domain *domain;
  46 };
  47 
  48 struct group_device {
  49         struct list_head list;
  50         struct device *dev;
  51         char *name;
  52 };
  53 
  54 struct iommu_group_attribute {
  55         struct attribute attr;
  56         ssize_t (*show)(struct iommu_group *group, char *buf);
  57         ssize_t (*store)(struct iommu_group *group,
  58                          const char *buf, size_t count);
  59 };
  60 
  61 static const char * const iommu_group_resv_type_string[] = {
  62         [IOMMU_RESV_DIRECT]                     = "direct",
  63         [IOMMU_RESV_DIRECT_RELAXABLE]           = "direct-relaxable",
  64         [IOMMU_RESV_RESERVED]                   = "reserved",
  65         [IOMMU_RESV_MSI]                        = "msi",
  66         [IOMMU_RESV_SW_MSI]                     = "msi",
  67 };
  68 
  69 #define IOMMU_CMD_LINE_DMA_API          BIT(0)
  70 
  71 static void iommu_set_cmd_line_dma_api(void)
  72 {
  73         iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API;
  74 }
  75 
  76 static bool iommu_cmd_line_dma_api(void)
  77 {
  78         return !!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API);
  79 }
  80 
  81 #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)           \
  82 struct iommu_group_attribute iommu_group_attr_##_name =         \
  83         __ATTR(_name, _mode, _show, _store)
  84 
  85 #define to_iommu_group_attr(_attr)      \
  86         container_of(_attr, struct iommu_group_attribute, attr)
  87 #define to_iommu_group(_kobj)           \
  88         container_of(_kobj, struct iommu_group, kobj)
  89 
  90 static LIST_HEAD(iommu_device_list);
  91 static DEFINE_SPINLOCK(iommu_device_lock);
  92 
  93 /*
  94  * Use a function instead of an array here because the domain-type is a
  95  * bit-field, so an array would waste memory.
  96  */
  97 static const char *iommu_domain_type_str(unsigned int t)
  98 {
  99         switch (t) {
 100         case IOMMU_DOMAIN_BLOCKED:
 101                 return "Blocked";
 102         case IOMMU_DOMAIN_IDENTITY:
 103                 return "Passthrough";
 104         case IOMMU_DOMAIN_UNMANAGED:
 105                 return "Unmanaged";
 106         case IOMMU_DOMAIN_DMA:
 107                 return "Translated";
 108         default:
 109                 return "Unknown";
 110         }
 111 }
 112 
 113 static int __init iommu_subsys_init(void)
 114 {
 115         bool cmd_line = iommu_cmd_line_dma_api();
 116 
 117         if (!cmd_line) {
 118                 if (IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH))
 119                         iommu_set_default_passthrough(false);
 120                 else
 121                         iommu_set_default_translated(false);
 122 
 123                 if (iommu_default_passthrough() && mem_encrypt_active()) {
 124                         pr_info("Memory encryption detected - Disabling default IOMMU Passthrough\n");
 125                         iommu_set_default_translated(false);
 126                 }
 127         }
 128 
 129         pr_info("Default domain type: %s %s\n",
 130                 iommu_domain_type_str(iommu_def_domain_type),
 131                 cmd_line ? "(set via kernel command line)" : "");
 132 
 133         return 0;
 134 }
 135 subsys_initcall(iommu_subsys_init);
 136 
 137 int iommu_device_register(struct iommu_device *iommu)
 138 {
 139         spin_lock(&iommu_device_lock);
 140         list_add_tail(&iommu->list, &iommu_device_list);
 141         spin_unlock(&iommu_device_lock);
 142         return 0;
 143 }
 144 
 145 void iommu_device_unregister(struct iommu_device *iommu)
 146 {
 147         spin_lock(&iommu_device_lock);
 148         list_del(&iommu->list);
 149         spin_unlock(&iommu_device_lock);
 150 }
 151 
 152 static struct iommu_param *iommu_get_dev_param(struct device *dev)
 153 {
 154         struct iommu_param *param = dev->iommu_param;
 155 
 156         if (param)
 157                 return param;
 158 
 159         param = kzalloc(sizeof(*param), GFP_KERNEL);
 160         if (!param)
 161                 return NULL;
 162 
 163         mutex_init(&param->lock);
 164         dev->iommu_param = param;
 165         return param;
 166 }
 167 
 168 static void iommu_free_dev_param(struct device *dev)
 169 {
 170         kfree(dev->iommu_param);
 171         dev->iommu_param = NULL;
 172 }
 173 
 174 int iommu_probe_device(struct device *dev)
 175 {
 176         const struct iommu_ops *ops = dev->bus->iommu_ops;
 177         int ret;
 178 
 179         WARN_ON(dev->iommu_group);
 180         if (!ops)
 181                 return -EINVAL;
 182 
 183         if (!iommu_get_dev_param(dev))
 184                 return -ENOMEM;
 185 
 186         ret = ops->add_device(dev);
 187         if (ret)
 188                 iommu_free_dev_param(dev);
 189 
 190         return ret;
 191 }
 192 
 193 void iommu_release_device(struct device *dev)
 194 {
 195         const struct iommu_ops *ops = dev->bus->iommu_ops;
 196 
 197         if (dev->iommu_group)
 198                 ops->remove_device(dev);
 199 
 200         iommu_free_dev_param(dev);
 201 }
 202 
 203 static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
 204                                                  unsigned type);
 205 static int __iommu_attach_device(struct iommu_domain *domain,
 206                                  struct device *dev);
 207 static int __iommu_attach_group(struct iommu_domain *domain,
 208                                 struct iommu_group *group);
 209 static void __iommu_detach_group(struct iommu_domain *domain,
 210                                  struct iommu_group *group);
 211 
 212 static int __init iommu_set_def_domain_type(char *str)
 213 {
 214         bool pt;
 215         int ret;
 216 
 217         ret = kstrtobool(str, &pt);
 218         if (ret)
 219                 return ret;
 220 
 221         if (pt)
 222                 iommu_set_default_passthrough(true);
 223         else
 224                 iommu_set_default_translated(true);
 225 
 226         return 0;
 227 }
 228 early_param("iommu.passthrough", iommu_set_def_domain_type);
 229 
 230 static int __init iommu_dma_setup(char *str)
 231 {
 232         return kstrtobool(str, &iommu_dma_strict);
 233 }
 234 early_param("iommu.strict", iommu_dma_setup);
 235 
 236 static ssize_t iommu_group_attr_show(struct kobject *kobj,
 237                                      struct attribute *__attr, char *buf)
 238 {
 239         struct iommu_group_attribute *attr = to_iommu_group_attr(__attr);
 240         struct iommu_group *group = to_iommu_group(kobj);
 241         ssize_t ret = -EIO;
 242 
 243         if (attr->show)
 244                 ret = attr->show(group, buf);
 245         return ret;
 246 }
 247 
 248 static ssize_t iommu_group_attr_store(struct kobject *kobj,
 249                                       struct attribute *__attr,
 250                                       const char *buf, size_t count)
 251 {
 252         struct iommu_group_attribute *attr = to_iommu_group_attr(__attr);
 253         struct iommu_group *group = to_iommu_group(kobj);
 254         ssize_t ret = -EIO;
 255 
 256         if (attr->store)
 257                 ret = attr->store(group, buf, count);
 258         return ret;
 259 }
 260 
 261 static const struct sysfs_ops iommu_group_sysfs_ops = {
 262         .show = iommu_group_attr_show,
 263         .store = iommu_group_attr_store,
 264 };
 265 
 266 static int iommu_group_create_file(struct iommu_group *group,
 267                                    struct iommu_group_attribute *attr)
 268 {
 269         return sysfs_create_file(&group->kobj, &attr->attr);
 270 }
 271 
 272 static void iommu_group_remove_file(struct iommu_group *group,
 273                                     struct iommu_group_attribute *attr)
 274 {
 275         sysfs_remove_file(&group->kobj, &attr->attr);
 276 }
 277 
 278 static ssize_t iommu_group_show_name(struct iommu_group *group, char *buf)
 279 {
 280         return sprintf(buf, "%s\n", group->name);
 281 }
 282 
 283 /**
 284  * iommu_insert_resv_region - Insert a new region in the
 285  * list of reserved regions.
 286  * @new: new region to insert
 287  * @regions: list of regions
 288  *
 289  * Elements are sorted by start address and overlapping segments
 290  * of the same type are merged.
 291  */
 292 int iommu_insert_resv_region(struct iommu_resv_region *new,
 293                              struct list_head *regions)
 294 {
 295         struct iommu_resv_region *iter, *tmp, *nr, *top;
 296         LIST_HEAD(stack);
 297 
 298         nr = iommu_alloc_resv_region(new->start, new->length,
 299                                      new->prot, new->type);
 300         if (!nr)
 301                 return -ENOMEM;
 302 
 303         /* First add the new element based on start address sorting */
 304         list_for_each_entry(iter, regions, list) {
 305                 if (nr->start < iter->start ||
 306                     (nr->start == iter->start && nr->type <= iter->type))
 307                         break;
 308         }
 309         list_add_tail(&nr->list, &iter->list);
 310 
 311         /* Merge overlapping segments of type nr->type in @regions, if any */
 312         list_for_each_entry_safe(iter, tmp, regions, list) {
 313                 phys_addr_t top_end, iter_end = iter->start + iter->length - 1;
 314 
 315                 /* no merge needed on elements of different types than @new */
 316                 if (iter->type != new->type) {
 317                         list_move_tail(&iter->list, &stack);
 318                         continue;
 319                 }
 320 
 321                 /* look for the last stack element of same type as @iter */
 322                 list_for_each_entry_reverse(top, &stack, list)
 323                         if (top->type == iter->type)
 324                                 goto check_overlap;
 325 
 326                 list_move_tail(&iter->list, &stack);
 327                 continue;
 328 
 329 check_overlap:
 330                 top_end = top->start + top->length - 1;
 331 
 332                 if (iter->start > top_end + 1) {
 333                         list_move_tail(&iter->list, &stack);
 334                 } else {
 335                         top->length = max(top_end, iter_end) - top->start + 1;
 336                         list_del(&iter->list);
 337                         kfree(iter);
 338                 }
 339         }
 340         list_splice(&stack, regions);
 341         return 0;
 342 }
 343 
 344 static int
 345 iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
 346                                  struct list_head *group_resv_regions)
 347 {
 348         struct iommu_resv_region *entry;
 349         int ret = 0;
 350 
 351         list_for_each_entry(entry, dev_resv_regions, list) {
 352                 ret = iommu_insert_resv_region(entry, group_resv_regions);
 353                 if (ret)
 354                         break;
 355         }
 356         return ret;
 357 }
 358 
 359 int iommu_get_group_resv_regions(struct iommu_group *group,
 360                                  struct list_head *head)
 361 {
 362         struct group_device *device;
 363         int ret = 0;
 364 
 365         mutex_lock(&group->mutex);
 366         list_for_each_entry(device, &group->devices, list) {
 367                 struct list_head dev_resv_regions;
 368 
 369                 INIT_LIST_HEAD(&dev_resv_regions);
 370                 iommu_get_resv_regions(device->dev, &dev_resv_regions);
 371                 ret = iommu_insert_device_resv_regions(&dev_resv_regions, head);
 372                 iommu_put_resv_regions(device->dev, &dev_resv_regions);
 373                 if (ret)
 374                         break;
 375         }
 376         mutex_unlock(&group->mutex);
 377         return ret;
 378 }
 379 EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions);
 380 
 381 static ssize_t iommu_group_show_resv_regions(struct iommu_group *group,
 382                                              char *buf)
 383 {
 384         struct iommu_resv_region *region, *next;
 385         struct list_head group_resv_regions;
 386         char *str = buf;
 387 
 388         INIT_LIST_HEAD(&group_resv_regions);
 389         iommu_get_group_resv_regions(group, &group_resv_regions);
 390 
 391         list_for_each_entry_safe(region, next, &group_resv_regions, list) {
 392                 str += sprintf(str, "0x%016llx 0x%016llx %s\n",
 393                                (long long int)region->start,
 394                                (long long int)(region->start +
 395                                                 region->length - 1),
 396                                iommu_group_resv_type_string[region->type]);
 397                 kfree(region);
 398         }
 399 
 400         return (str - buf);
 401 }
 402 
 403 static ssize_t iommu_group_show_type(struct iommu_group *group,
 404                                      char *buf)
 405 {
 406         char *type = "unknown\n";
 407 
 408         if (group->default_domain) {
 409                 switch (group->default_domain->type) {
 410                 case IOMMU_DOMAIN_BLOCKED:
 411                         type = "blocked\n";
 412                         break;
 413                 case IOMMU_DOMAIN_IDENTITY:
 414                         type = "identity\n";
 415                         break;
 416                 case IOMMU_DOMAIN_UNMANAGED:
 417                         type = "unmanaged\n";
 418                         break;
 419                 case IOMMU_DOMAIN_DMA:
 420                         type = "DMA\n";
 421                         break;
 422                 }
 423         }
 424         strcpy(buf, type);
 425 
 426         return strlen(type);
 427 }
 428 
 429 static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
 430 
 431 static IOMMU_GROUP_ATTR(reserved_regions, 0444,
 432                         iommu_group_show_resv_regions, NULL);
 433 
 434 static IOMMU_GROUP_ATTR(type, 0444, iommu_group_show_type, NULL);
 435 
 436 static void iommu_group_release(struct kobject *kobj)
 437 {
 438         struct iommu_group *group = to_iommu_group(kobj);
 439 
 440         pr_debug("Releasing group %d\n", group->id);
 441 
 442         if (group->iommu_data_release)
 443                 group->iommu_data_release(group->iommu_data);
 444 
 445         ida_simple_remove(&iommu_group_ida, group->id);
 446 
 447         if (group->default_domain)
 448                 iommu_domain_free(group->default_domain);
 449 
 450         kfree(group->name);
 451         kfree(group);
 452 }
 453 
 454 static struct kobj_type iommu_group_ktype = {
 455         .sysfs_ops = &iommu_group_sysfs_ops,
 456         .release = iommu_group_release,
 457 };
 458 
 459 /**
 460  * iommu_group_alloc - Allocate a new group
 461  *
 462  * This function is called by an iommu driver to allocate a new iommu
 463  * group.  The iommu group represents the minimum granularity of the iommu.
 464  * Upon successful return, the caller holds a reference to the supplied
 465  * group in order to hold the group until devices are added.  Use
 466  * iommu_group_put() to release this extra reference count, allowing the
 467  * group to be automatically reclaimed once it has no devices or external
 468  * references.
 469  */
 470 struct iommu_group *iommu_group_alloc(void)
 471 {
 472         struct iommu_group *group;
 473         int ret;
 474 
 475         group = kzalloc(sizeof(*group), GFP_KERNEL);
 476         if (!group)
 477                 return ERR_PTR(-ENOMEM);
 478 
 479         group->kobj.kset = iommu_group_kset;
 480         mutex_init(&group->mutex);
 481         INIT_LIST_HEAD(&group->devices);
 482         BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
 483 
 484         ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL);
 485         if (ret < 0) {
 486                 kfree(group);
 487                 return ERR_PTR(ret);
 488         }
 489         group->id = ret;
 490 
 491         ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype,
 492                                    NULL, "%d", group->id);
 493         if (ret) {
 494                 ida_simple_remove(&iommu_group_ida, group->id);
 495                 kobject_put(&group->kobj);
 496                 return ERR_PTR(ret);
 497         }
 498 
 499         group->devices_kobj = kobject_create_and_add("devices", &group->kobj);
 500         if (!group->devices_kobj) {
 501                 kobject_put(&group->kobj); /* triggers .release & free */
 502                 return ERR_PTR(-ENOMEM);
 503         }
 504 
 505         /*
 506          * The devices_kobj holds a reference on the group kobject, so
 507          * as long as that exists so will the group.  We can therefore
 508          * use the devices_kobj for reference counting.
 509          */
 510         kobject_put(&group->kobj);
 511 
 512         ret = iommu_group_create_file(group,
 513                                       &iommu_group_attr_reserved_regions);
 514         if (ret)
 515                 return ERR_PTR(ret);
 516 
 517         ret = iommu_group_create_file(group, &iommu_group_attr_type);
 518         if (ret)
 519                 return ERR_PTR(ret);
 520 
 521         pr_debug("Allocated group %d\n", group->id);
 522 
 523         return group;
 524 }
 525 EXPORT_SYMBOL_GPL(iommu_group_alloc);
 526 
 527 struct iommu_group *iommu_group_get_by_id(int id)
 528 {
 529         struct kobject *group_kobj;
 530         struct iommu_group *group;
 531         const char *name;
 532 
 533         if (!iommu_group_kset)
 534                 return NULL;
 535 
 536         name = kasprintf(GFP_KERNEL, "%d", id);
 537         if (!name)
 538                 return NULL;
 539 
 540         group_kobj = kset_find_obj(iommu_group_kset, name);
 541         kfree(name);
 542 
 543         if (!group_kobj)
 544                 return NULL;
 545 
 546         group = container_of(group_kobj, struct iommu_group, kobj);
 547         BUG_ON(group->id != id);
 548 
 549         kobject_get(group->devices_kobj);
 550         kobject_put(&group->kobj);
 551 
 552         return group;
 553 }
 554 EXPORT_SYMBOL_GPL(iommu_group_get_by_id);
 555 
 556 /**
 557  * iommu_group_get_iommudata - retrieve iommu_data registered for a group
 558  * @group: the group
 559  *
 560  * iommu drivers can store data in the group for use when doing iommu
 561  * operations.  This function provides a way to retrieve it.  Caller
 562  * should hold a group reference.
 563  */
 564 void *iommu_group_get_iommudata(struct iommu_group *group)
 565 {
 566         return group->iommu_data;
 567 }
 568 EXPORT_SYMBOL_GPL(iommu_group_get_iommudata);
 569 
 570 /**
 571  * iommu_group_set_iommudata - set iommu_data for a group
 572  * @group: the group
 573  * @iommu_data: new data
 574  * @release: release function for iommu_data
 575  *
 576  * iommu drivers can store data in the group for use when doing iommu
 577  * operations.  This function provides a way to set the data after
 578  * the group has been allocated.  Caller should hold a group reference.
 579  */
 580 void iommu_group_set_iommudata(struct iommu_group *group, void *iommu_data,
 581                                void (*release)(void *iommu_data))
 582 {
 583         group->iommu_data = iommu_data;
 584         group->iommu_data_release = release;
 585 }
 586 EXPORT_SYMBOL_GPL(iommu_group_set_iommudata);
 587 
 588 /**
 589  * iommu_group_set_name - set name for a group
 590  * @group: the group
 591  * @name: name
 592  *
 593  * Allow iommu driver to set a name for a group.  When set it will
 594  * appear in a name attribute file under the group in sysfs.
 595  */
 596 int iommu_group_set_name(struct iommu_group *group, const char *name)
 597 {
 598         int ret;
 599 
 600         if (group->name) {
 601                 iommu_group_remove_file(group, &iommu_group_attr_name);
 602                 kfree(group->name);
 603                 group->name = NULL;
 604                 if (!name)
 605                         return 0;
 606         }
 607 
 608         group->name = kstrdup(name, GFP_KERNEL);
 609         if (!group->name)
 610                 return -ENOMEM;
 611 
 612         ret = iommu_group_create_file(group, &iommu_group_attr_name);
 613         if (ret) {
 614                 kfree(group->name);
 615                 group->name = NULL;
 616                 return ret;
 617         }
 618 
 619         return 0;
 620 }
 621 EXPORT_SYMBOL_GPL(iommu_group_set_name);
 622 
 623 static int iommu_group_create_direct_mappings(struct iommu_group *group,
 624                                               struct device *dev)
 625 {
 626         struct iommu_domain *domain = group->default_domain;
 627         struct iommu_resv_region *entry;
 628         struct list_head mappings;
 629         unsigned long pg_size;
 630         int ret = 0;
 631 
 632         if (!domain || domain->type != IOMMU_DOMAIN_DMA)
 633                 return 0;
 634 
 635         BUG_ON(!domain->pgsize_bitmap);
 636 
 637         pg_size = 1UL << __ffs(domain->pgsize_bitmap);
 638         INIT_LIST_HEAD(&mappings);
 639 
 640         iommu_get_resv_regions(dev, &mappings);
 641 
 642         /* We need to consider overlapping regions for different devices */
 643         list_for_each_entry(entry, &mappings, list) {
 644                 dma_addr_t start, end, addr;
 645 
 646                 if (domain->ops->apply_resv_region)
 647                         domain->ops->apply_resv_region(dev, domain, entry);
 648 
 649                 start = ALIGN(entry->start, pg_size);
 650                 end   = ALIGN(entry->start + entry->length, pg_size);
 651 
 652                 if (entry->type != IOMMU_RESV_DIRECT &&
 653                     entry->type != IOMMU_RESV_DIRECT_RELAXABLE)
 654                         continue;
 655 
 656                 for (addr = start; addr < end; addr += pg_size) {
 657                         phys_addr_t phys_addr;
 658 
 659                         phys_addr = iommu_iova_to_phys(domain, addr);
 660                         if (phys_addr)
 661                                 continue;
 662 
 663                         ret = iommu_map(domain, addr, addr, pg_size, entry->prot);
 664                         if (ret)
 665                                 goto out;
 666                 }
 667 
 668         }
 669 
 670         iommu_flush_tlb_all(domain);
 671 
 672 out:
 673         iommu_put_resv_regions(dev, &mappings);
 674 
 675         return ret;
 676 }
 677 
 678 /**
 679  * iommu_group_add_device - add a device to an iommu group
 680  * @group: the group into which to add the device (reference should be held)
 681  * @dev: the device
 682  *
 683  * This function is called by an iommu driver to add a device into a
 684  * group.  Adding a device increments the group reference count.
 685  */
 686 int iommu_group_add_device(struct iommu_group *group, struct device *dev)
 687 {
 688         int ret, i = 0;
 689         struct group_device *device;
 690 
 691         device = kzalloc(sizeof(*device), GFP_KERNEL);
 692         if (!device)
 693                 return -ENOMEM;
 694 
 695         device->dev = dev;
 696 
 697         ret = sysfs_create_link(&dev->kobj, &group->kobj, "iommu_group");
 698         if (ret)
 699                 goto err_free_device;
 700 
 701         device->name = kasprintf(GFP_KERNEL, "%s", kobject_name(&dev->kobj));
 702 rename:
 703         if (!device->name) {
 704                 ret = -ENOMEM;
 705                 goto err_remove_link;
 706         }
 707 
 708         ret = sysfs_create_link_nowarn(group->devices_kobj,
 709                                        &dev->kobj, device->name);
 710         if (ret) {
 711                 if (ret == -EEXIST && i >= 0) {
 712                         /*
 713                          * Account for the slim chance of collision
 714                          * and append an instance to the name.
 715                          */
 716                         kfree(device->name);
 717                         device->name = kasprintf(GFP_KERNEL, "%s.%d",
 718                                                  kobject_name(&dev->kobj), i++);
 719                         goto rename;
 720                 }
 721                 goto err_free_name;
 722         }
 723 
 724         kobject_get(group->devices_kobj);
 725 
 726         dev->iommu_group = group;
 727 
 728         iommu_group_create_direct_mappings(group, dev);
 729 
 730         mutex_lock(&group->mutex);
 731         list_add_tail(&device->list, &group->devices);
 732         if (group->domain)
 733                 ret = __iommu_attach_device(group->domain, dev);
 734         mutex_unlock(&group->mutex);
 735         if (ret)
 736                 goto err_put_group;
 737 
 738         /* Notify any listeners about change to group. */
 739         blocking_notifier_call_chain(&group->notifier,
 740                                      IOMMU_GROUP_NOTIFY_ADD_DEVICE, dev);
 741 
 742         trace_add_device_to_group(group->id, dev);
 743 
 744         dev_info(dev, "Adding to iommu group %d\n", group->id);
 745 
 746         return 0;
 747 
 748 err_put_group:
 749         mutex_lock(&group->mutex);
 750         list_del(&device->list);
 751         mutex_unlock(&group->mutex);
 752         dev->iommu_group = NULL;
 753         kobject_put(group->devices_kobj);
 754         sysfs_remove_link(group->devices_kobj, device->name);
 755 err_free_name:
 756         kfree(device->name);
 757 err_remove_link:
 758         sysfs_remove_link(&dev->kobj, "iommu_group");
 759 err_free_device:
 760         kfree(device);
 761         dev_err(dev, "Failed to add to iommu group %d: %d\n", group->id, ret);
 762         return ret;
 763 }
 764 EXPORT_SYMBOL_GPL(iommu_group_add_device);
 765 
 766 /**
 767  * iommu_group_remove_device - remove a device from it's current group
 768  * @dev: device to be removed
 769  *
 770  * This function is called by an iommu driver to remove the device from
 771  * it's current group.  This decrements the iommu group reference count.
 772  */
 773 void iommu_group_remove_device(struct device *dev)
 774 {
 775         struct iommu_group *group = dev->iommu_group;
 776         struct group_device *tmp_device, *device = NULL;
 777 
 778         dev_info(dev, "Removing from iommu group %d\n", group->id);
 779 
 780         /* Pre-notify listeners that a device is being removed. */
 781         blocking_notifier_call_chain(&group->notifier,
 782                                      IOMMU_GROUP_NOTIFY_DEL_DEVICE, dev);
 783 
 784         mutex_lock(&group->mutex);
 785         list_for_each_entry(tmp_device, &group->devices, list) {
 786                 if (tmp_device->dev == dev) {
 787                         device = tmp_device;
 788                         list_del(&device->list);
 789                         break;
 790                 }
 791         }
 792         mutex_unlock(&group->mutex);
 793 
 794         if (!device)
 795                 return;
 796 
 797         sysfs_remove_link(group->devices_kobj, device->name);
 798         sysfs_remove_link(&dev->kobj, "iommu_group");
 799 
 800         trace_remove_device_from_group(group->id, dev);
 801 
 802         kfree(device->name);
 803         kfree(device);
 804         dev->iommu_group = NULL;
 805         kobject_put(group->devices_kobj);
 806 }
 807 EXPORT_SYMBOL_GPL(iommu_group_remove_device);
 808 
 809 static int iommu_group_device_count(struct iommu_group *group)
 810 {
 811         struct group_device *entry;
 812         int ret = 0;
 813 
 814         list_for_each_entry(entry, &group->devices, list)
 815                 ret++;
 816 
 817         return ret;
 818 }
 819 
 820 /**
 821  * iommu_group_for_each_dev - iterate over each device in the group
 822  * @group: the group
 823  * @data: caller opaque data to be passed to callback function
 824  * @fn: caller supplied callback function
 825  *
 826  * This function is called by group users to iterate over group devices.
 827  * Callers should hold a reference count to the group during callback.
 828  * The group->mutex is held across callbacks, which will block calls to
 829  * iommu_group_add/remove_device.
 830  */
 831 static int __iommu_group_for_each_dev(struct iommu_group *group, void *data,
 832                                       int (*fn)(struct device *, void *))
 833 {
 834         struct group_device *device;
 835         int ret = 0;
 836 
 837         list_for_each_entry(device, &group->devices, list) {
 838                 ret = fn(device->dev, data);
 839                 if (ret)
 840                         break;
 841         }
 842         return ret;
 843 }
 844 
 845 
 846 int iommu_group_for_each_dev(struct iommu_group *group, void *data,
 847                              int (*fn)(struct device *, void *))
 848 {
 849         int ret;
 850 
 851         mutex_lock(&group->mutex);
 852         ret = __iommu_group_for_each_dev(group, data, fn);
 853         mutex_unlock(&group->mutex);
 854 
 855         return ret;
 856 }
 857 EXPORT_SYMBOL_GPL(iommu_group_for_each_dev);
 858 
 859 /**
 860  * iommu_group_get - Return the group for a device and increment reference
 861  * @dev: get the group that this device belongs to
 862  *
 863  * This function is called by iommu drivers and users to get the group
 864  * for the specified device.  If found, the group is returned and the group
 865  * reference in incremented, else NULL.
 866  */
 867 struct iommu_group *iommu_group_get(struct device *dev)
 868 {
 869         struct iommu_group *group = dev->iommu_group;
 870 
 871         if (group)
 872                 kobject_get(group->devices_kobj);
 873 
 874         return group;
 875 }
 876 EXPORT_SYMBOL_GPL(iommu_group_get);
 877 
 878 /**
 879  * iommu_group_ref_get - Increment reference on a group
 880  * @group: the group to use, must not be NULL
 881  *
 882  * This function is called by iommu drivers to take additional references on an
 883  * existing group.  Returns the given group for convenience.
 884  */
 885 struct iommu_group *iommu_group_ref_get(struct iommu_group *group)
 886 {
 887         kobject_get(group->devices_kobj);
 888         return group;
 889 }
 890 
 891 /**
 892  * iommu_group_put - Decrement group reference
 893  * @group: the group to use
 894  *
 895  * This function is called by iommu drivers and users to release the
 896  * iommu group.  Once the reference count is zero, the group is released.
 897  */
 898 void iommu_group_put(struct iommu_group *group)
 899 {
 900         if (group)
 901                 kobject_put(group->devices_kobj);
 902 }
 903 EXPORT_SYMBOL_GPL(iommu_group_put);
 904 
 905 /**
 906  * iommu_group_register_notifier - Register a notifier for group changes
 907  * @group: the group to watch
 908  * @nb: notifier block to signal
 909  *
 910  * This function allows iommu group users to track changes in a group.
 911  * See include/linux/iommu.h for actions sent via this notifier.  Caller
 912  * should hold a reference to the group throughout notifier registration.
 913  */
 914 int iommu_group_register_notifier(struct iommu_group *group,
 915                                   struct notifier_block *nb)
 916 {
 917         return blocking_notifier_chain_register(&group->notifier, nb);
 918 }
 919 EXPORT_SYMBOL_GPL(iommu_group_register_notifier);
 920 
 921 /**
 922  * iommu_group_unregister_notifier - Unregister a notifier
 923  * @group: the group to watch
 924  * @nb: notifier block to signal
 925  *
 926  * Unregister a previously registered group notifier block.
 927  */
 928 int iommu_group_unregister_notifier(struct iommu_group *group,
 929                                     struct notifier_block *nb)
 930 {
 931         return blocking_notifier_chain_unregister(&group->notifier, nb);
 932 }
 933 EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier);
 934 
 935 /**
 936  * iommu_register_device_fault_handler() - Register a device fault handler
 937  * @dev: the device
 938  * @handler: the fault handler
 939  * @data: private data passed as argument to the handler
 940  *
 941  * When an IOMMU fault event is received, this handler gets called with the
 942  * fault event and data as argument. The handler should return 0 on success. If
 943  * the fault is recoverable (IOMMU_FAULT_PAGE_REQ), the consumer should also
 944  * complete the fault by calling iommu_page_response() with one of the following
 945  * response code:
 946  * - IOMMU_PAGE_RESP_SUCCESS: retry the translation
 947  * - IOMMU_PAGE_RESP_INVALID: terminate the fault
 948  * - IOMMU_PAGE_RESP_FAILURE: terminate the fault and stop reporting
 949  *   page faults if possible.
 950  *
 951  * Return 0 if the fault handler was installed successfully, or an error.
 952  */
 953 int iommu_register_device_fault_handler(struct device *dev,
 954                                         iommu_dev_fault_handler_t handler,
 955                                         void *data)
 956 {
 957         struct iommu_param *param = dev->iommu_param;
 958         int ret = 0;
 959 
 960         if (!param)
 961                 return -EINVAL;
 962 
 963         mutex_lock(&param->lock);
 964         /* Only allow one fault handler registered for each device */
 965         if (param->fault_param) {
 966                 ret = -EBUSY;
 967                 goto done_unlock;
 968         }
 969 
 970         get_device(dev);
 971         param->fault_param = kzalloc(sizeof(*param->fault_param), GFP_KERNEL);
 972         if (!param->fault_param) {
 973                 put_device(dev);
 974                 ret = -ENOMEM;
 975                 goto done_unlock;
 976         }
 977         param->fault_param->handler = handler;
 978         param->fault_param->data = data;
 979         mutex_init(&param->fault_param->lock);
 980         INIT_LIST_HEAD(&param->fault_param->faults);
 981 
 982 done_unlock:
 983         mutex_unlock(&param->lock);
 984 
 985         return ret;
 986 }
 987 EXPORT_SYMBOL_GPL(iommu_register_device_fault_handler);
 988 
 989 /**
 990  * iommu_unregister_device_fault_handler() - Unregister the device fault handler
 991  * @dev: the device
 992  *
 993  * Remove the device fault handler installed with
 994  * iommu_register_device_fault_handler().
 995  *
 996  * Return 0 on success, or an error.
 997  */
 998 int iommu_unregister_device_fault_handler(struct device *dev)
 999 {
1000         struct iommu_param *param = dev->iommu_param;
1001         int ret = 0;
1002 
1003         if (!param)
1004                 return -EINVAL;
1005 
1006         mutex_lock(&param->lock);
1007 
1008         if (!param->fault_param)
1009                 goto unlock;
1010 
1011         /* we cannot unregister handler if there are pending faults */
1012         if (!list_empty(&param->fault_param->faults)) {
1013                 ret = -EBUSY;
1014                 goto unlock;
1015         }
1016 
1017         kfree(param->fault_param);
1018         param->fault_param = NULL;
1019         put_device(dev);
1020 unlock:
1021         mutex_unlock(&param->lock);
1022 
1023         return ret;
1024 }
1025 EXPORT_SYMBOL_GPL(iommu_unregister_device_fault_handler);
1026 
1027 /**
1028  * iommu_report_device_fault() - Report fault event to device driver
1029  * @dev: the device
1030  * @evt: fault event data
1031  *
1032  * Called by IOMMU drivers when a fault is detected, typically in a threaded IRQ
1033  * handler. When this function fails and the fault is recoverable, it is the
1034  * caller's responsibility to complete the fault.
1035  *
1036  * Return 0 on success, or an error.
1037  */
1038 int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt)
1039 {
1040         struct iommu_param *param = dev->iommu_param;
1041         struct iommu_fault_event *evt_pending = NULL;
1042         struct iommu_fault_param *fparam;
1043         int ret = 0;
1044 
1045         if (!param || !evt)
1046                 return -EINVAL;
1047 
1048         /* we only report device fault if there is a handler registered */
1049         mutex_lock(&param->lock);
1050         fparam = param->fault_param;
1051         if (!fparam || !fparam->handler) {
1052                 ret = -EINVAL;
1053                 goto done_unlock;
1054         }
1055 
1056         if (evt->fault.type == IOMMU_FAULT_PAGE_REQ &&
1057             (evt->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) {
1058                 evt_pending = kmemdup(evt, sizeof(struct iommu_fault_event),
1059                                       GFP_KERNEL);
1060                 if (!evt_pending) {
1061                         ret = -ENOMEM;
1062                         goto done_unlock;
1063                 }
1064                 mutex_lock(&fparam->lock);
1065                 list_add_tail(&evt_pending->list, &fparam->faults);
1066                 mutex_unlock(&fparam->lock);
1067         }
1068 
1069         ret = fparam->handler(&evt->fault, fparam->data);
1070         if (ret && evt_pending) {
1071                 mutex_lock(&fparam->lock);
1072                 list_del(&evt_pending->list);
1073                 mutex_unlock(&fparam->lock);
1074                 kfree(evt_pending);
1075         }
1076 done_unlock:
1077         mutex_unlock(&param->lock);
1078         return ret;
1079 }
1080 EXPORT_SYMBOL_GPL(iommu_report_device_fault);
1081 
1082 int iommu_page_response(struct device *dev,
1083                         struct iommu_page_response *msg)
1084 {
1085         bool pasid_valid;
1086         int ret = -EINVAL;
1087         struct iommu_fault_event *evt;
1088         struct iommu_fault_page_request *prm;
1089         struct iommu_param *param = dev->iommu_param;
1090         struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
1091 
1092         if (!domain || !domain->ops->page_response)
1093                 return -ENODEV;
1094 
1095         if (!param || !param->fault_param)
1096                 return -EINVAL;
1097 
1098         if (msg->version != IOMMU_PAGE_RESP_VERSION_1 ||
1099             msg->flags & ~IOMMU_PAGE_RESP_PASID_VALID)
1100                 return -EINVAL;
1101 
1102         /* Only send response if there is a fault report pending */
1103         mutex_lock(&param->fault_param->lock);
1104         if (list_empty(&param->fault_param->faults)) {
1105                 dev_warn_ratelimited(dev, "no pending PRQ, drop response\n");
1106                 goto done_unlock;
1107         }
1108         /*
1109          * Check if we have a matching page request pending to respond,
1110          * otherwise return -EINVAL
1111          */
1112         list_for_each_entry(evt, &param->fault_param->faults, list) {
1113                 prm = &evt->fault.prm;
1114                 pasid_valid = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
1115 
1116                 if ((pasid_valid && prm->pasid != msg->pasid) ||
1117                     prm->grpid != msg->grpid)
1118                         continue;
1119 
1120                 /* Sanitize the reply */
1121                 msg->flags = pasid_valid ? IOMMU_PAGE_RESP_PASID_VALID : 0;
1122 
1123                 ret = domain->ops->page_response(dev, evt, msg);
1124                 list_del(&evt->list);
1125                 kfree(evt);
1126                 break;
1127         }
1128 
1129 done_unlock:
1130         mutex_unlock(&param->fault_param->lock);
1131         return ret;
1132 }
1133 EXPORT_SYMBOL_GPL(iommu_page_response);
1134 
1135 /**
1136  * iommu_group_id - Return ID for a group
1137  * @group: the group to ID
1138  *
1139  * Return the unique ID for the group matching the sysfs group number.
1140  */
1141 int iommu_group_id(struct iommu_group *group)
1142 {
1143         return group->id;
1144 }
1145 EXPORT_SYMBOL_GPL(iommu_group_id);
1146 
1147 static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev,
1148                                                unsigned long *devfns);
1149 
1150 /*
1151  * To consider a PCI device isolated, we require ACS to support Source
1152  * Validation, Request Redirection, Completer Redirection, and Upstream
1153  * Forwarding.  This effectively means that devices cannot spoof their
1154  * requester ID, requests and completions cannot be redirected, and all
1155  * transactions are forwarded upstream, even as it passes through a
1156  * bridge where the target device is downstream.
1157  */
1158 #define REQ_ACS_FLAGS   (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
1159 
1160 /*
1161  * For multifunction devices which are not isolated from each other, find
1162  * all the other non-isolated functions and look for existing groups.  For
1163  * each function, we also need to look for aliases to or from other devices
1164  * that may already have a group.
1165  */
1166 static struct iommu_group *get_pci_function_alias_group(struct pci_dev *pdev,
1167                                                         unsigned long *devfns)
1168 {
1169         struct pci_dev *tmp = NULL;
1170         struct iommu_group *group;
1171 
1172         if (!pdev->multifunction || pci_acs_enabled(pdev, REQ_ACS_FLAGS))
1173                 return NULL;
1174 
1175         for_each_pci_dev(tmp) {
1176                 if (tmp == pdev || tmp->bus != pdev->bus ||
1177                     PCI_SLOT(tmp->devfn) != PCI_SLOT(pdev->devfn) ||
1178                     pci_acs_enabled(tmp, REQ_ACS_FLAGS))
1179                         continue;
1180 
1181                 group = get_pci_alias_group(tmp, devfns);
1182                 if (group) {
1183                         pci_dev_put(tmp);
1184                         return group;
1185                 }
1186         }
1187 
1188         return NULL;
1189 }
1190 
1191 /*
1192  * Look for aliases to or from the given device for existing groups. DMA
1193  * aliases are only supported on the same bus, therefore the search
1194  * space is quite small (especially since we're really only looking at pcie
1195  * device, and therefore only expect multiple slots on the root complex or
1196  * downstream switch ports).  It's conceivable though that a pair of
1197  * multifunction devices could have aliases between them that would cause a
1198  * loop.  To prevent this, we use a bitmap to track where we've been.
1199  */
1200 static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev,
1201                                                unsigned long *devfns)
1202 {
1203         struct pci_dev *tmp = NULL;
1204         struct iommu_group *group;
1205 
1206         if (test_and_set_bit(pdev->devfn & 0xff, devfns))
1207                 return NULL;
1208 
1209         group = iommu_group_get(&pdev->dev);
1210         if (group)
1211                 return group;
1212 
1213         for_each_pci_dev(tmp) {
1214                 if (tmp == pdev || tmp->bus != pdev->bus)
1215                         continue;
1216 
1217                 /* We alias them or they alias us */
1218                 if (pci_devs_are_dma_aliases(pdev, tmp)) {
1219                         group = get_pci_alias_group(tmp, devfns);
1220                         if (group) {
1221                                 pci_dev_put(tmp);
1222                                 return group;
1223                         }
1224 
1225                         group = get_pci_function_alias_group(tmp, devfns);
1226                         if (group) {
1227                                 pci_dev_put(tmp);
1228                                 return group;
1229                         }
1230                 }
1231         }
1232 
1233         return NULL;
1234 }
1235 
1236 struct group_for_pci_data {
1237         struct pci_dev *pdev;
1238         struct iommu_group *group;
1239 };
1240 
1241 /*
1242  * DMA alias iterator callback, return the last seen device.  Stop and return
1243  * the IOMMU group if we find one along the way.
1244  */
1245 static int get_pci_alias_or_group(struct pci_dev *pdev, u16 alias, void *opaque)
1246 {
1247         struct group_for_pci_data *data = opaque;
1248 
1249         data->pdev = pdev;
1250         data->group = iommu_group_get(&pdev->dev);
1251 
1252         return data->group != NULL;
1253 }
1254 
1255 /*
1256  * Generic device_group call-back function. It just allocates one
1257  * iommu-group per device.
1258  */
1259 struct iommu_group *generic_device_group(struct device *dev)
1260 {
1261         return iommu_group_alloc();
1262 }
1263 
1264 /*
1265  * Use standard PCI bus topology, isolation features, and DMA alias quirks
1266  * to find or create an IOMMU group for a device.
1267  */
1268 struct iommu_group *pci_device_group(struct device *dev)
1269 {
1270         struct pci_dev *pdev = to_pci_dev(dev);
1271         struct group_for_pci_data data;
1272         struct pci_bus *bus;
1273         struct iommu_group *group = NULL;
1274         u64 devfns[4] = { 0 };
1275 
1276         if (WARN_ON(!dev_is_pci(dev)))
1277                 return ERR_PTR(-EINVAL);
1278 
1279         /*
1280          * Find the upstream DMA alias for the device.  A device must not
1281          * be aliased due to topology in order to have its own IOMMU group.
1282          * If we find an alias along the way that already belongs to a
1283          * group, use it.
1284          */
1285         if (pci_for_each_dma_alias(pdev, get_pci_alias_or_group, &data))
1286                 return data.group;
1287 
1288         pdev = data.pdev;
1289 
1290         /*
1291          * Continue upstream from the point of minimum IOMMU granularity
1292          * due to aliases to the point where devices are protected from
1293          * peer-to-peer DMA by PCI ACS.  Again, if we find an existing
1294          * group, use it.
1295          */
1296         for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
1297                 if (!bus->self)
1298                         continue;
1299 
1300                 if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS))
1301                         break;
1302 
1303                 pdev = bus->self;
1304 
1305                 group = iommu_group_get(&pdev->dev);
1306                 if (group)
1307                         return group;
1308         }
1309 
1310         /*
1311          * Look for existing groups on device aliases.  If we alias another
1312          * device or another device aliases us, use the same group.
1313          */
1314         group = get_pci_alias_group(pdev, (unsigned long *)devfns);
1315         if (group)
1316                 return group;
1317 
1318         /*
1319          * Look for existing groups on non-isolated functions on the same
1320          * slot and aliases of those funcions, if any.  No need to clear
1321          * the search bitmap, the tested devfns are still valid.
1322          */
1323         group = get_pci_function_alias_group(pdev, (unsigned long *)devfns);
1324         if (group)
1325                 return group;
1326 
1327         /* No shared group found, allocate new */
1328         return iommu_group_alloc();
1329 }
1330 
1331 /* Get the IOMMU group for device on fsl-mc bus */
1332 struct iommu_group *fsl_mc_device_group(struct device *dev)
1333 {
1334         struct device *cont_dev = fsl_mc_cont_dev(dev);
1335         struct iommu_group *group;
1336 
1337         group = iommu_group_get(cont_dev);
1338         if (!group)
1339                 group = iommu_group_alloc();
1340         return group;
1341 }
1342 
1343 /**
1344  * iommu_group_get_for_dev - Find or create the IOMMU group for a device
1345  * @dev: target device
1346  *
1347  * This function is intended to be called by IOMMU drivers and extended to
1348  * support common, bus-defined algorithms when determining or creating the
1349  * IOMMU group for a device.  On success, the caller will hold a reference
1350  * to the returned IOMMU group, which will already include the provided
1351  * device.  The reference should be released with iommu_group_put().
1352  */
1353 struct iommu_group *iommu_group_get_for_dev(struct device *dev)
1354 {
1355         const struct iommu_ops *ops = dev->bus->iommu_ops;
1356         struct iommu_group *group;
1357         int ret;
1358 
1359         group = iommu_group_get(dev);
1360         if (group)
1361                 return group;
1362 
1363         if (!ops)
1364                 return ERR_PTR(-EINVAL);
1365 
1366         group = ops->device_group(dev);
1367         if (WARN_ON_ONCE(group == NULL))
1368                 return ERR_PTR(-EINVAL);
1369 
1370         if (IS_ERR(group))
1371                 return group;
1372 
1373         /*
1374          * Try to allocate a default domain - needs support from the
1375          * IOMMU driver.
1376          */
1377         if (!group->default_domain) {
1378                 struct iommu_domain *dom;
1379 
1380                 dom = __iommu_domain_alloc(dev->bus, iommu_def_domain_type);
1381                 if (!dom && iommu_def_domain_type != IOMMU_DOMAIN_DMA) {
1382                         dom = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_DMA);
1383                         if (dom) {
1384                                 dev_warn(dev,
1385                                          "failed to allocate default IOMMU domain of type %u; falling back to IOMMU_DOMAIN_DMA",
1386                                          iommu_def_domain_type);
1387                         }
1388                 }
1389 
1390                 group->default_domain = dom;
1391                 if (!group->domain)
1392                         group->domain = dom;
1393 
1394                 if (dom && !iommu_dma_strict) {
1395                         int attr = 1;
1396                         iommu_domain_set_attr(dom,
1397                                               DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
1398                                               &attr);
1399                 }
1400         }
1401 
1402         ret = iommu_group_add_device(group, dev);
1403         if (ret) {
1404                 iommu_group_put(group);
1405                 return ERR_PTR(ret);
1406         }
1407 
1408         return group;
1409 }
1410 
1411 struct iommu_domain *iommu_group_default_domain(struct iommu_group *group)
1412 {
1413         return group->default_domain;
1414 }
1415 
1416 static int add_iommu_group(struct device *dev, void *data)
1417 {
1418         int ret = iommu_probe_device(dev);
1419 
1420         /*
1421          * We ignore -ENODEV errors for now, as they just mean that the
1422          * device is not translated by an IOMMU. We still care about
1423          * other errors and fail to initialize when they happen.
1424          */
1425         if (ret == -ENODEV)
1426                 ret = 0;
1427 
1428         return ret;
1429 }
1430 
1431 static int remove_iommu_group(struct device *dev, void *data)
1432 {
1433         iommu_release_device(dev);
1434 
1435         return 0;
1436 }
1437 
1438 static int iommu_bus_notifier(struct notifier_block *nb,
1439                               unsigned long action, void *data)
1440 {
1441         unsigned long group_action = 0;
1442         struct device *dev = data;
1443         struct iommu_group *group;
1444 
1445         /*
1446          * ADD/DEL call into iommu driver ops if provided, which may
1447          * result in ADD/DEL notifiers to group->notifier
1448          */
1449         if (action == BUS_NOTIFY_ADD_DEVICE) {
1450                 int ret;
1451 
1452                 ret = iommu_probe_device(dev);
1453                 return (ret) ? NOTIFY_DONE : NOTIFY_OK;
1454         } else if (action == BUS_NOTIFY_REMOVED_DEVICE) {
1455                 iommu_release_device(dev);
1456                 return NOTIFY_OK;
1457         }
1458 
1459         /*
1460          * Remaining BUS_NOTIFYs get filtered and republished to the
1461          * group, if anyone is listening
1462          */
1463         group = iommu_group_get(dev);
1464         if (!group)
1465                 return 0;
1466 
1467         switch (action) {
1468         case BUS_NOTIFY_BIND_DRIVER:
1469                 group_action = IOMMU_GROUP_NOTIFY_BIND_DRIVER;
1470                 break;
1471         case BUS_NOTIFY_BOUND_DRIVER:
1472                 group_action = IOMMU_GROUP_NOTIFY_BOUND_DRIVER;
1473                 break;
1474         case BUS_NOTIFY_UNBIND_DRIVER:
1475                 group_action = IOMMU_GROUP_NOTIFY_UNBIND_DRIVER;
1476                 break;
1477         case BUS_NOTIFY_UNBOUND_DRIVER:
1478                 group_action = IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER;
1479                 break;
1480         }
1481 
1482         if (group_action)
1483                 blocking_notifier_call_chain(&group->notifier,
1484                                              group_action, dev);
1485 
1486         iommu_group_put(group);
1487         return 0;
1488 }
1489 
1490 static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
1491 {
1492         int err;
1493         struct notifier_block *nb;
1494 
1495         nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
1496         if (!nb)
1497                 return -ENOMEM;
1498 
1499         nb->notifier_call = iommu_bus_notifier;
1500 
1501         err = bus_register_notifier(bus, nb);
1502         if (err)
1503                 goto out_free;
1504 
1505         err = bus_for_each_dev(bus, NULL, NULL, add_iommu_group);
1506         if (err)
1507                 goto out_err;
1508 
1509 
1510         return 0;
1511 
1512 out_err:
1513         /* Clean up */
1514         bus_for_each_dev(bus, NULL, NULL, remove_iommu_group);
1515         bus_unregister_notifier(bus, nb);
1516 
1517 out_free:
1518         kfree(nb);
1519 
1520         return err;
1521 }
1522 
1523 /**
1524  * bus_set_iommu - set iommu-callbacks for the bus
1525  * @bus: bus.
1526  * @ops: the callbacks provided by the iommu-driver
1527  *
1528  * This function is called by an iommu driver to set the iommu methods
1529  * used for a particular bus. Drivers for devices on that bus can use
1530  * the iommu-api after these ops are registered.
1531  * This special function is needed because IOMMUs are usually devices on
1532  * the bus itself, so the iommu drivers are not initialized when the bus
1533  * is set up. With this function the iommu-driver can set the iommu-ops
1534  * afterwards.
1535  */
1536 int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
1537 {
1538         int err;
1539 
1540         if (bus->iommu_ops != NULL)
1541                 return -EBUSY;
1542 
1543         bus->iommu_ops = ops;
1544 
1545         /* Do IOMMU specific setup for this bus-type */
1546         err = iommu_bus_init(bus, ops);
1547         if (err)
1548                 bus->iommu_ops = NULL;
1549 
1550         return err;
1551 }
1552 EXPORT_SYMBOL_GPL(bus_set_iommu);
1553 
1554 bool iommu_present(struct bus_type *bus)
1555 {
1556         return bus->iommu_ops != NULL;
1557 }
1558 EXPORT_SYMBOL_GPL(iommu_present);
1559 
1560 bool iommu_capable(struct bus_type *bus, enum iommu_cap cap)
1561 {
1562         if (!bus->iommu_ops || !bus->iommu_ops->capable)
1563                 return false;
1564 
1565         return bus->iommu_ops->capable(cap);
1566 }
1567 EXPORT_SYMBOL_GPL(iommu_capable);
1568 
1569 /**
1570  * iommu_set_fault_handler() - set a fault handler for an iommu domain
1571  * @domain: iommu domain
1572  * @handler: fault handler
1573  * @token: user data, will be passed back to the fault handler
1574  *
1575  * This function should be used by IOMMU users which want to be notified
1576  * whenever an IOMMU fault happens.
1577  *
1578  * The fault handler itself should return 0 on success, and an appropriate
1579  * error code otherwise.
1580  */
1581 void iommu_set_fault_handler(struct iommu_domain *domain,
1582                                         iommu_fault_handler_t handler,
1583                                         void *token)
1584 {
1585         BUG_ON(!domain);
1586 
1587         domain->handler = handler;
1588         domain->handler_token = token;
1589 }
1590 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
1591 
1592 static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
1593                                                  unsigned type)
1594 {
1595         struct iommu_domain *domain;
1596 
1597         if (bus == NULL || bus->iommu_ops == NULL)
1598                 return NULL;
1599 
1600         domain = bus->iommu_ops->domain_alloc(type);
1601         if (!domain)
1602                 return NULL;
1603 
1604         domain->ops  = bus->iommu_ops;
1605         domain->type = type;
1606         /* Assume all sizes by default; the driver may override this later */
1607         domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;
1608 
1609         return domain;
1610 }
1611 
1612 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
1613 {
1614         return __iommu_domain_alloc(bus, IOMMU_DOMAIN_UNMANAGED);
1615 }
1616 EXPORT_SYMBOL_GPL(iommu_domain_alloc);
1617 
1618 void iommu_domain_free(struct iommu_domain *domain)
1619 {
1620         domain->ops->domain_free(domain);
1621 }
1622 EXPORT_SYMBOL_GPL(iommu_domain_free);
1623 
1624 static int __iommu_attach_device(struct iommu_domain *domain,
1625                                  struct device *dev)
1626 {
1627         int ret;
1628         if ((domain->ops->is_attach_deferred != NULL) &&
1629             domain->ops->is_attach_deferred(domain, dev))
1630                 return 0;
1631 
1632         if (unlikely(domain->ops->attach_dev == NULL))
1633                 return -ENODEV;
1634 
1635         ret = domain->ops->attach_dev(domain, dev);
1636         if (!ret)
1637                 trace_attach_device_to_domain(dev);
1638         return ret;
1639 }
1640 
1641 int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
1642 {
1643         struct iommu_group *group;
1644         int ret;
1645 
1646         group = iommu_group_get(dev);
1647         if (!group)
1648                 return -ENODEV;
1649 
1650         /*
1651          * Lock the group to make sure the device-count doesn't
1652          * change while we are attaching
1653          */
1654         mutex_lock(&group->mutex);
1655         ret = -EINVAL;
1656         if (iommu_group_device_count(group) != 1)
1657                 goto out_unlock;
1658 
1659         ret = __iommu_attach_group(domain, group);
1660 
1661 out_unlock:
1662         mutex_unlock(&group->mutex);
1663         iommu_group_put(group);
1664 
1665         return ret;
1666 }
1667 EXPORT_SYMBOL_GPL(iommu_attach_device);
1668 
1669 static void __iommu_detach_device(struct iommu_domain *domain,
1670                                   struct device *dev)
1671 {
1672         if ((domain->ops->is_attach_deferred != NULL) &&
1673             domain->ops->is_attach_deferred(domain, dev))
1674                 return;
1675 
1676         if (unlikely(domain->ops->detach_dev == NULL))
1677                 return;
1678 
1679         domain->ops->detach_dev(domain, dev);
1680         trace_detach_device_from_domain(dev);
1681 }
1682 
1683 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
1684 {
1685         struct iommu_group *group;
1686 
1687         group = iommu_group_get(dev);
1688         if (!group)
1689                 return;
1690 
1691         mutex_lock(&group->mutex);
1692         if (iommu_group_device_count(group) != 1) {
1693                 WARN_ON(1);
1694                 goto out_unlock;
1695         }
1696 
1697         __iommu_detach_group(domain, group);
1698 
1699 out_unlock:
1700         mutex_unlock(&group->mutex);
1701         iommu_group_put(group);
1702 }
1703 EXPORT_SYMBOL_GPL(iommu_detach_device);
1704 
1705 struct iommu_domain *iommu_get_domain_for_dev(struct device *dev)
1706 {
1707         struct iommu_domain *domain;
1708         struct iommu_group *group;
1709 
1710         group = iommu_group_get(dev);
1711         if (!group)
1712                 return NULL;
1713 
1714         domain = group->domain;
1715 
1716         iommu_group_put(group);
1717 
1718         return domain;
1719 }
1720 EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev);
1721 
1722 /*
1723  * For IOMMU_DOMAIN_DMA implementations which already provide their own
1724  * guarantees that the group and its default domain are valid and correct.
1725  */
1726 struct iommu_domain *iommu_get_dma_domain(struct device *dev)
1727 {
1728         return dev->iommu_group->default_domain;
1729 }
1730 
1731 /*
1732  * IOMMU groups are really the natural working unit of the IOMMU, but
1733  * the IOMMU API works on domains and devices.  Bridge that gap by
1734  * iterating over the devices in a group.  Ideally we'd have a single
1735  * device which represents the requestor ID of the group, but we also
1736  * allow IOMMU drivers to create policy defined minimum sets, where
1737  * the physical hardware may be able to distiguish members, but we
1738  * wish to group them at a higher level (ex. untrusted multi-function
1739  * PCI devices).  Thus we attach each device.
1740  */
1741 static int iommu_group_do_attach_device(struct device *dev, void *data)
1742 {
1743         struct iommu_domain *domain = data;
1744 
1745         return __iommu_attach_device(domain, dev);
1746 }
1747 
1748 static int __iommu_attach_group(struct iommu_domain *domain,
1749                                 struct iommu_group *group)
1750 {
1751         int ret;
1752 
1753         if (group->default_domain && group->domain != group->default_domain)
1754                 return -EBUSY;
1755 
1756         ret = __iommu_group_for_each_dev(group, domain,
1757                                          iommu_group_do_attach_device);
1758         if (ret == 0)
1759                 group->domain = domain;
1760 
1761         return ret;
1762 }
1763 
1764 int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
1765 {
1766         int ret;
1767 
1768         mutex_lock(&group->mutex);
1769         ret = __iommu_attach_group(domain, group);
1770         mutex_unlock(&group->mutex);
1771 
1772         return ret;
1773 }
1774 EXPORT_SYMBOL_GPL(iommu_attach_group);
1775 
1776 static int iommu_group_do_detach_device(struct device *dev, void *data)
1777 {
1778         struct iommu_domain *domain = data;
1779 
1780         __iommu_detach_device(domain, dev);
1781 
1782         return 0;
1783 }
1784 
1785 static void __iommu_detach_group(struct iommu_domain *domain,
1786                                  struct iommu_group *group)
1787 {
1788         int ret;
1789 
1790         if (!group->default_domain) {
1791                 __iommu_group_for_each_dev(group, domain,
1792                                            iommu_group_do_detach_device);
1793                 group->domain = NULL;
1794                 return;
1795         }
1796 
1797         if (group->domain == group->default_domain)
1798                 return;
1799 
1800         /* Detach by re-attaching to the default domain */
1801         ret = __iommu_group_for_each_dev(group, group->default_domain,
1802                                          iommu_group_do_attach_device);
1803         if (ret != 0)
1804                 WARN_ON(1);
1805         else
1806                 group->domain = group->default_domain;
1807 }
1808 
1809 void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group)
1810 {
1811         mutex_lock(&group->mutex);
1812         __iommu_detach_group(domain, group);
1813         mutex_unlock(&group->mutex);
1814 }
1815 EXPORT_SYMBOL_GPL(iommu_detach_group);
1816 
1817 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
1818 {
1819         if (unlikely(domain->ops->iova_to_phys == NULL))
1820                 return 0;
1821 
1822         return domain->ops->iova_to_phys(domain, iova);
1823 }
1824 EXPORT_SYMBOL_GPL(iommu_iova_to_phys);
1825 
1826 static size_t iommu_pgsize(struct iommu_domain *domain,
1827                            unsigned long addr_merge, size_t size)
1828 {
1829         unsigned int pgsize_idx;
1830         size_t pgsize;
1831 
1832         /* Max page size that still fits into 'size' */
1833         pgsize_idx = __fls(size);
1834 
1835         /* need to consider alignment requirements ? */
1836         if (likely(addr_merge)) {
1837                 /* Max page size allowed by address */
1838                 unsigned int align_pgsize_idx = __ffs(addr_merge);
1839                 pgsize_idx = min(pgsize_idx, align_pgsize_idx);
1840         }
1841 
1842         /* build a mask of acceptable page sizes */
1843         pgsize = (1UL << (pgsize_idx + 1)) - 1;
1844 
1845         /* throw away page sizes not supported by the hardware */
1846         pgsize &= domain->pgsize_bitmap;
1847 
1848         /* make sure we're still sane */
1849         BUG_ON(!pgsize);
1850 
1851         /* pick the biggest page */
1852         pgsize_idx = __fls(pgsize);
1853         pgsize = 1UL << pgsize_idx;
1854 
1855         return pgsize;
1856 }
1857 
1858 int iommu_map(struct iommu_domain *domain, unsigned long iova,
1859               phys_addr_t paddr, size_t size, int prot)
1860 {
1861         const struct iommu_ops *ops = domain->ops;
1862         unsigned long orig_iova = iova;
1863         unsigned int min_pagesz;
1864         size_t orig_size = size;
1865         phys_addr_t orig_paddr = paddr;
1866         int ret = 0;
1867 
1868         if (unlikely(ops->map == NULL ||
1869                      domain->pgsize_bitmap == 0UL))
1870                 return -ENODEV;
1871 
1872         if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
1873                 return -EINVAL;
1874 
1875         /* find out the minimum page size supported */
1876         min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
1877 
1878         /*
1879          * both the virtual address and the physical one, as well as
1880          * the size of the mapping, must be aligned (at least) to the
1881          * size of the smallest page supported by the hardware
1882          */
1883         if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) {
1884                 pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%x\n",
1885                        iova, &paddr, size, min_pagesz);
1886                 return -EINVAL;
1887         }
1888 
1889         pr_debug("map: iova 0x%lx pa %pa size 0x%zx\n", iova, &paddr, size);
1890 
1891         while (size) {
1892                 size_t pgsize = iommu_pgsize(domain, iova | paddr, size);
1893 
1894                 pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx\n",
1895                          iova, &paddr, pgsize);
1896 
1897                 ret = ops->map(domain, iova, paddr, pgsize, prot);
1898                 if (ret)
1899                         break;
1900 
1901                 iova += pgsize;
1902                 paddr += pgsize;
1903                 size -= pgsize;
1904         }
1905 
1906         if (ops->iotlb_sync_map)
1907                 ops->iotlb_sync_map(domain);
1908 
1909         /* unroll mapping in case something went wrong */
1910         if (ret)
1911                 iommu_unmap(domain, orig_iova, orig_size - size);
1912         else
1913                 trace_map(orig_iova, orig_paddr, orig_size);
1914 
1915         return ret;
1916 }
1917 EXPORT_SYMBOL_GPL(iommu_map);
1918 
1919 static size_t __iommu_unmap(struct iommu_domain *domain,
1920                             unsigned long iova, size_t size,
1921                             struct iommu_iotlb_gather *iotlb_gather)
1922 {
1923         const struct iommu_ops *ops = domain->ops;
1924         size_t unmapped_page, unmapped = 0;
1925         unsigned long orig_iova = iova;
1926         unsigned int min_pagesz;
1927 
1928         if (unlikely(ops->unmap == NULL ||
1929                      domain->pgsize_bitmap == 0UL))
1930                 return 0;
1931 
1932         if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
1933                 return 0;
1934 
1935         /* find out the minimum page size supported */
1936         min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
1937 
1938         /*
1939          * The virtual address, as well as the size of the mapping, must be
1940          * aligned (at least) to the size of the smallest page supported
1941          * by the hardware
1942          */
1943         if (!IS_ALIGNED(iova | size, min_pagesz)) {
1944                 pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n",
1945                        iova, size, min_pagesz);
1946                 return 0;
1947         }
1948 
1949         pr_debug("unmap this: iova 0x%lx size 0x%zx\n", iova, size);
1950 
1951         /*
1952          * Keep iterating until we either unmap 'size' bytes (or more)
1953          * or we hit an area that isn't mapped.
1954          */
1955         while (unmapped < size) {
1956                 size_t pgsize = iommu_pgsize(domain, iova, size - unmapped);
1957 
1958                 unmapped_page = ops->unmap(domain, iova, pgsize, iotlb_gather);
1959                 if (!unmapped_page)
1960                         break;
1961 
1962                 pr_debug("unmapped: iova 0x%lx size 0x%zx\n",
1963                          iova, unmapped_page);
1964 
1965                 iova += unmapped_page;
1966                 unmapped += unmapped_page;
1967         }
1968 
1969         trace_unmap(orig_iova, size, unmapped);
1970         return unmapped;
1971 }
1972 
1973 size_t iommu_unmap(struct iommu_domain *domain,
1974                    unsigned long iova, size_t size)
1975 {
1976         struct iommu_iotlb_gather iotlb_gather;
1977         size_t ret;
1978 
1979         iommu_iotlb_gather_init(&iotlb_gather);
1980         ret = __iommu_unmap(domain, iova, size, &iotlb_gather);
1981         iommu_tlb_sync(domain, &iotlb_gather);
1982 
1983         return ret;
1984 }
1985 EXPORT_SYMBOL_GPL(iommu_unmap);
1986 
1987 size_t iommu_unmap_fast(struct iommu_domain *domain,
1988                         unsigned long iova, size_t size,
1989                         struct iommu_iotlb_gather *iotlb_gather)
1990 {
1991         return __iommu_unmap(domain, iova, size, iotlb_gather);
1992 }
1993 EXPORT_SYMBOL_GPL(iommu_unmap_fast);
1994 
1995 size_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
1996                     struct scatterlist *sg, unsigned int nents, int prot)
1997 {
1998         size_t len = 0, mapped = 0;
1999         phys_addr_t start;
2000         unsigned int i = 0;
2001         int ret;
2002 
2003         while (i <= nents) {
2004                 phys_addr_t s_phys = sg_phys(sg);
2005 
2006                 if (len && s_phys != start + len) {
2007                         ret = iommu_map(domain, iova + mapped, start, len, prot);
2008                         if (ret)
2009                                 goto out_err;
2010 
2011                         mapped += len;
2012                         len = 0;
2013                 }
2014 
2015                 if (len) {
2016                         len += sg->length;
2017                 } else {
2018                         len = sg->length;
2019                         start = s_phys;
2020                 }
2021 
2022                 if (++i < nents)
2023                         sg = sg_next(sg);
2024         }
2025 
2026         return mapped;
2027 
2028 out_err:
2029         /* undo mappings already done */
2030         iommu_unmap(domain, iova, mapped);
2031 
2032         return 0;
2033 
2034 }
2035 EXPORT_SYMBOL_GPL(iommu_map_sg);
2036 
2037 int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr,
2038                                phys_addr_t paddr, u64 size, int prot)
2039 {
2040         if (unlikely(domain->ops->domain_window_enable == NULL))
2041                 return -ENODEV;
2042 
2043         return domain->ops->domain_window_enable(domain, wnd_nr, paddr, size,
2044                                                  prot);
2045 }
2046 EXPORT_SYMBOL_GPL(iommu_domain_window_enable);
2047 
2048 void iommu_domain_window_disable(struct iommu_domain *domain, u32 wnd_nr)
2049 {
2050         if (unlikely(domain->ops->domain_window_disable == NULL))
2051                 return;
2052 
2053         return domain->ops->domain_window_disable(domain, wnd_nr);
2054 }
2055 EXPORT_SYMBOL_GPL(iommu_domain_window_disable);
2056 
2057 /**
2058  * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
2059  * @domain: the iommu domain where the fault has happened
2060  * @dev: the device where the fault has happened
2061  * @iova: the faulting address
2062  * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
2063  *
2064  * This function should be called by the low-level IOMMU implementations
2065  * whenever IOMMU faults happen, to allow high-level users, that are
2066  * interested in such events, to know about them.
2067  *
2068  * This event may be useful for several possible use cases:
2069  * - mere logging of the event
2070  * - dynamic TLB/PTE loading
2071  * - if restarting of the faulting device is required
2072  *
2073  * Returns 0 on success and an appropriate error code otherwise (if dynamic
2074  * PTE/TLB loading will one day be supported, implementations will be able
2075  * to tell whether it succeeded or not according to this return value).
2076  *
2077  * Specifically, -ENOSYS is returned if a fault handler isn't installed
2078  * (though fault handlers can also return -ENOSYS, in case they want to
2079  * elicit the default behavior of the IOMMU drivers).
2080  */
2081 int report_iommu_fault(struct iommu_domain *domain, struct device *dev,
2082                        unsigned long iova, int flags)
2083 {
2084         int ret = -ENOSYS;
2085 
2086         /*
2087          * if upper layers showed interest and installed a fault handler,
2088          * invoke it.
2089          */
2090         if (domain->handler)
2091                 ret = domain->handler(domain, dev, iova, flags,
2092                                                 domain->handler_token);
2093 
2094         trace_io_page_fault(dev, iova, flags);
2095         return ret;
2096 }
2097 EXPORT_SYMBOL_GPL(report_iommu_fault);
2098 
2099 static int __init iommu_init(void)
2100 {
2101         iommu_group_kset = kset_create_and_add("iommu_groups",
2102                                                NULL, kernel_kobj);
2103         BUG_ON(!iommu_group_kset);
2104 
2105         iommu_debugfs_setup();
2106 
2107         return 0;
2108 }
2109 core_initcall(iommu_init);
2110 
2111 int iommu_domain_get_attr(struct iommu_domain *domain,
2112                           enum iommu_attr attr, void *data)
2113 {
2114         struct iommu_domain_geometry *geometry;
2115         bool *paging;
2116         int ret = 0;
2117 
2118         switch (attr) {
2119         case DOMAIN_ATTR_GEOMETRY:
2120                 geometry  = data;
2121                 *geometry = domain->geometry;
2122 
2123                 break;
2124         case DOMAIN_ATTR_PAGING:
2125                 paging  = data;
2126                 *paging = (domain->pgsize_bitmap != 0UL);
2127                 break;
2128         default:
2129                 if (!domain->ops->domain_get_attr)
2130                         return -EINVAL;
2131 
2132                 ret = domain->ops->domain_get_attr(domain, attr, data);
2133         }
2134 
2135         return ret;
2136 }
2137 EXPORT_SYMBOL_GPL(iommu_domain_get_attr);
2138 
2139 int iommu_domain_set_attr(struct iommu_domain *domain,
2140                           enum iommu_attr attr, void *data)
2141 {
2142         int ret = 0;
2143 
2144         switch (attr) {
2145         default:
2146                 if (domain->ops->domain_set_attr == NULL)
2147                         return -EINVAL;
2148 
2149                 ret = domain->ops->domain_set_attr(domain, attr, data);
2150         }
2151 
2152         return ret;
2153 }
2154 EXPORT_SYMBOL_GPL(iommu_domain_set_attr);
2155 
2156 void iommu_get_resv_regions(struct device *dev, struct list_head *list)
2157 {
2158         const struct iommu_ops *ops = dev->bus->iommu_ops;
2159 
2160         if (ops && ops->get_resv_regions)
2161                 ops->get_resv_regions(dev, list);
2162 }
2163 
2164 void iommu_put_resv_regions(struct device *dev, struct list_head *list)
2165 {
2166         const struct iommu_ops *ops = dev->bus->iommu_ops;
2167 
2168         if (ops && ops->put_resv_regions)
2169                 ops->put_resv_regions(dev, list);
2170 }
2171 
2172 struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
2173                                                   size_t length, int prot,
2174                                                   enum iommu_resv_type type)
2175 {
2176         struct iommu_resv_region *region;
2177 
2178         region = kzalloc(sizeof(*region), GFP_KERNEL);
2179         if (!region)
2180                 return NULL;
2181 
2182         INIT_LIST_HEAD(&region->list);
2183         region->start = start;
2184         region->length = length;
2185         region->prot = prot;
2186         region->type = type;
2187         return region;
2188 }
2189 
2190 static int
2191 request_default_domain_for_dev(struct device *dev, unsigned long type)
2192 {
2193         struct iommu_domain *domain;
2194         struct iommu_group *group;
2195         int ret;
2196 
2197         /* Device must already be in a group before calling this function */
2198         group = iommu_group_get(dev);
2199         if (!group)
2200                 return -EINVAL;
2201 
2202         mutex_lock(&group->mutex);
2203 
2204         ret = 0;
2205         if (group->default_domain && group->default_domain->type == type)
2206                 goto out;
2207 
2208         /* Don't change mappings of existing devices */
2209         ret = -EBUSY;
2210         if (iommu_group_device_count(group) != 1)
2211                 goto out;
2212 
2213         ret = -ENOMEM;
2214         domain = __iommu_domain_alloc(dev->bus, type);
2215         if (!domain)
2216                 goto out;
2217 
2218         /* Attach the device to the domain */
2219         ret = __iommu_attach_group(domain, group);
2220         if (ret) {
2221                 iommu_domain_free(domain);
2222                 goto out;
2223         }
2224 
2225         /* Make the domain the default for this group */
2226         if (group->default_domain)
2227                 iommu_domain_free(group->default_domain);
2228         group->default_domain = domain;
2229 
2230         iommu_group_create_direct_mappings(group, dev);
2231 
2232         dev_info(dev, "Using iommu %s mapping\n",
2233                  type == IOMMU_DOMAIN_DMA ? "dma" : "direct");
2234 
2235         ret = 0;
2236 out:
2237         mutex_unlock(&group->mutex);
2238         iommu_group_put(group);
2239 
2240         return ret;
2241 }
2242 
2243 /* Request that a device is direct mapped by the IOMMU */
2244 int iommu_request_dm_for_dev(struct device *dev)
2245 {
2246         return request_default_domain_for_dev(dev, IOMMU_DOMAIN_IDENTITY);
2247 }
2248 
2249 /* Request that a device can't be direct mapped by the IOMMU */
2250 int iommu_request_dma_domain_for_dev(struct device *dev)
2251 {
2252         return request_default_domain_for_dev(dev, IOMMU_DOMAIN_DMA);
2253 }
2254 
2255 void iommu_set_default_passthrough(bool cmd_line)
2256 {
2257         if (cmd_line)
2258                 iommu_set_cmd_line_dma_api();
2259 
2260         iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
2261 }
2262 
2263 void iommu_set_default_translated(bool cmd_line)
2264 {
2265         if (cmd_line)
2266                 iommu_set_cmd_line_dma_api();
2267 
2268         iommu_def_domain_type = IOMMU_DOMAIN_DMA;
2269 }
2270 
2271 bool iommu_default_passthrough(void)
2272 {
2273         return iommu_def_domain_type == IOMMU_DOMAIN_IDENTITY;
2274 }
2275 EXPORT_SYMBOL_GPL(iommu_default_passthrough);
2276 
2277 const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode)
2278 {
2279         const struct iommu_ops *ops = NULL;
2280         struct iommu_device *iommu;
2281 
2282         spin_lock(&iommu_device_lock);
2283         list_for_each_entry(iommu, &iommu_device_list, list)
2284                 if (iommu->fwnode == fwnode) {
2285                         ops = iommu->ops;
2286                         break;
2287                 }
2288         spin_unlock(&iommu_device_lock);
2289         return ops;
2290 }
2291 
2292 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
2293                       const struct iommu_ops *ops)
2294 {
2295         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
2296 
2297         if (fwspec)
2298                 return ops == fwspec->ops ? 0 : -EINVAL;
2299 
2300         fwspec = kzalloc(sizeof(*fwspec), GFP_KERNEL);
2301         if (!fwspec)
2302                 return -ENOMEM;
2303 
2304         of_node_get(to_of_node(iommu_fwnode));
2305         fwspec->iommu_fwnode = iommu_fwnode;
2306         fwspec->ops = ops;
2307         dev_iommu_fwspec_set(dev, fwspec);
2308         return 0;
2309 }
2310 EXPORT_SYMBOL_GPL(iommu_fwspec_init);
2311 
2312 void iommu_fwspec_free(struct device *dev)
2313 {
2314         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
2315 
2316         if (fwspec) {
2317                 fwnode_handle_put(fwspec->iommu_fwnode);
2318                 kfree(fwspec);
2319                 dev_iommu_fwspec_set(dev, NULL);
2320         }
2321 }
2322 EXPORT_SYMBOL_GPL(iommu_fwspec_free);
2323 
2324 int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids)
2325 {
2326         struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
2327         size_t size;
2328         int i;
2329 
2330         if (!fwspec)
2331                 return -EINVAL;
2332 
2333         size = offsetof(struct iommu_fwspec, ids[fwspec->num_ids + num_ids]);
2334         if (size > sizeof(*fwspec)) {
2335                 fwspec = krealloc(fwspec, size, GFP_KERNEL);
2336                 if (!fwspec)
2337                         return -ENOMEM;
2338 
2339                 dev_iommu_fwspec_set(dev, fwspec);
2340         }
2341 
2342         for (i = 0; i < num_ids; i++)
2343                 fwspec->ids[fwspec->num_ids + i] = ids[i];
2344 
2345         fwspec->num_ids += num_ids;
2346         return 0;
2347 }
2348 EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
2349 
2350 /*
2351  * Per device IOMMU features.
2352  */
2353 bool iommu_dev_has_feature(struct device *dev, enum iommu_dev_features feat)
2354 {
2355         const struct iommu_ops *ops = dev->bus->iommu_ops;
2356 
2357         if (ops && ops->dev_has_feat)
2358                 return ops->dev_has_feat(dev, feat);
2359 
2360         return false;
2361 }
2362 EXPORT_SYMBOL_GPL(iommu_dev_has_feature);
2363 
2364 int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
2365 {
2366         const struct iommu_ops *ops = dev->bus->iommu_ops;
2367 
2368         if (ops && ops->dev_enable_feat)
2369                 return ops->dev_enable_feat(dev, feat);
2370 
2371         return -ENODEV;
2372 }
2373 EXPORT_SYMBOL_GPL(iommu_dev_enable_feature);
2374 
2375 /*
2376  * The device drivers should do the necessary cleanups before calling this.
2377  * For example, before disabling the aux-domain feature, the device driver
2378  * should detach all aux-domains. Otherwise, this will return -EBUSY.
2379  */
2380 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
2381 {
2382         const struct iommu_ops *ops = dev->bus->iommu_ops;
2383 
2384         if (ops && ops->dev_disable_feat)
2385                 return ops->dev_disable_feat(dev, feat);
2386 
2387         return -EBUSY;
2388 }
2389 EXPORT_SYMBOL_GPL(iommu_dev_disable_feature);
2390 
2391 bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
2392 {
2393         const struct iommu_ops *ops = dev->bus->iommu_ops;
2394 
2395         if (ops && ops->dev_feat_enabled)
2396                 return ops->dev_feat_enabled(dev, feat);
2397 
2398         return false;
2399 }
2400 EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
2401 
2402 /*
2403  * Aux-domain specific attach/detach.
2404  *
2405  * Only works if iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) returns
2406  * true. Also, as long as domains are attached to a device through this
2407  * interface, any tries to call iommu_attach_device() should fail
2408  * (iommu_detach_device() can't fail, so we fail when trying to re-attach).
2409  * This should make us safe against a device being attached to a guest as a
2410  * whole while there are still pasid users on it (aux and sva).
2411  */
2412 int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
2413 {
2414         int ret = -ENODEV;
2415 
2416         if (domain->ops->aux_attach_dev)
2417                 ret = domain->ops->aux_attach_dev(domain, dev);
2418 
2419         if (!ret)
2420                 trace_attach_device_to_domain(dev);
2421 
2422         return ret;
2423 }
2424 EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
2425 
2426 void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
2427 {
2428         if (domain->ops->aux_detach_dev) {
2429                 domain->ops->aux_detach_dev(domain, dev);
2430                 trace_detach_device_from_domain(dev);
2431         }
2432 }
2433 EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
2434 
2435 int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
2436 {
2437         int ret = -ENODEV;
2438 
2439         if (domain->ops->aux_get_pasid)
2440                 ret = domain->ops->aux_get_pasid(domain, dev);
2441 
2442         return ret;
2443 }
2444 EXPORT_SYMBOL_GPL(iommu_aux_get_pasid);
2445 
2446 /**
2447  * iommu_sva_bind_device() - Bind a process address space to a device
2448  * @dev: the device
2449  * @mm: the mm to bind, caller must hold a reference to it
2450  *
2451  * Create a bond between device and address space, allowing the device to access
2452  * the mm using the returned PASID. If a bond already exists between @device and
2453  * @mm, it is returned and an additional reference is taken. Caller must call
2454  * iommu_sva_unbind_device() to release each reference.
2455  *
2456  * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
2457  * initialize the required SVA features.
2458  *
2459  * On error, returns an ERR_PTR value.
2460  */
2461 struct iommu_sva *
2462 iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
2463 {
2464         struct iommu_group *group;
2465         struct iommu_sva *handle = ERR_PTR(-EINVAL);
2466         const struct iommu_ops *ops = dev->bus->iommu_ops;
2467 
2468         if (!ops || !ops->sva_bind)
2469                 return ERR_PTR(-ENODEV);
2470 
2471         group = iommu_group_get(dev);
2472         if (!group)
2473                 return ERR_PTR(-ENODEV);
2474 
2475         /* Ensure device count and domain don't change while we're binding */
2476         mutex_lock(&group->mutex);
2477 
2478         /*
2479          * To keep things simple, SVA currently doesn't support IOMMU groups
2480          * with more than one device. Existing SVA-capable systems are not
2481          * affected by the problems that required IOMMU groups (lack of ACS
2482          * isolation, device ID aliasing and other hardware issues).
2483          */
2484         if (iommu_group_device_count(group) != 1)
2485                 goto out_unlock;
2486 
2487         handle = ops->sva_bind(dev, mm, drvdata);
2488 
2489 out_unlock:
2490         mutex_unlock(&group->mutex);
2491         iommu_group_put(group);
2492 
2493         return handle;
2494 }
2495 EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
2496 
2497 /**
2498  * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
2499  * @handle: the handle returned by iommu_sva_bind_device()
2500  *
2501  * Put reference to a bond between device and address space. The device should
2502  * not be issuing any more transaction for this PASID. All outstanding page
2503  * requests for this PASID must have been flushed to the IOMMU.
2504  *
2505  * Returns 0 on success, or an error value
2506  */
2507 void iommu_sva_unbind_device(struct iommu_sva *handle)
2508 {
2509         struct iommu_group *group;
2510         struct device *dev = handle->dev;
2511         const struct iommu_ops *ops = dev->bus->iommu_ops;
2512 
2513         if (!ops || !ops->sva_unbind)
2514                 return;
2515 
2516         group = iommu_group_get(dev);
2517         if (!group)
2518                 return;
2519 
2520         mutex_lock(&group->mutex);
2521         ops->sva_unbind(handle);
2522         mutex_unlock(&group->mutex);
2523 
2524         iommu_group_put(group);
2525 }
2526 EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
2527 
2528 int iommu_sva_set_ops(struct iommu_sva *handle,
2529                       const struct iommu_sva_ops *sva_ops)
2530 {
2531         if (handle->ops && handle->ops != sva_ops)
2532                 return -EEXIST;
2533 
2534         handle->ops = sva_ops;
2535         return 0;
2536 }
2537 EXPORT_SYMBOL_GPL(iommu_sva_set_ops);
2538 
2539 int iommu_sva_get_pasid(struct iommu_sva *handle)
2540 {
2541         const struct iommu_ops *ops = handle->dev->bus->iommu_ops;
2542 
2543         if (!ops || !ops->sva_get_pasid)
2544                 return IOMMU_PASID_INVALID;
2545 
2546         return ops->sva_get_pasid(handle);
2547 }
2548 EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/iommu/iommu.c

DEFINITIONS
