xref: /linux/drivers/iommu/iommu.c (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a)
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/amba/bus.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/bits.h>
13 #include <linux/bug.h>
14 #include <linux/types.h>
15 #include <linux/init.h>
16 #include <linux/export.h>
17 #include <linux/slab.h>
18 #include <linux/errno.h>
19 #include <linux/host1x_context_bus.h>
20 #include <linux/iommu.h>
21 #include <linux/idr.h>
22 #include <linux/err.h>
23 #include <linux/pci.h>
24 #include <linux/pci-ats.h>
25 #include <linux/bitops.h>
26 #include <linux/platform_device.h>
27 #include <linux/property.h>
28 #include <linux/fsl/mc.h>
29 #include <linux/module.h>
30 #include <linux/cc_platform.h>
31 #include <linux/cdx/cdx_bus.h>
32 #include <trace/events/iommu.h>
33 #include <linux/sched/mm.h>
34 #include <linux/msi.h>
35 #include <uapi/linux/iommufd.h>
36 
37 #include "dma-iommu.h"
38 #include "iommu-priv.h"
39 
40 static struct kset *iommu_group_kset;
41 static DEFINE_IDA(iommu_group_ida);
42 static DEFINE_IDA(iommu_global_pasid_ida);
43 
44 static unsigned int iommu_def_domain_type __read_mostly;
45 static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT);
46 static u32 iommu_cmd_line __read_mostly;
47 
48 struct iommu_group {
49 	struct kobject kobj;
50 	struct kobject *devices_kobj;
51 	struct list_head devices;
52 	struct xarray pasid_array;
53 	struct mutex mutex;
54 	void *iommu_data;
55 	void (*iommu_data_release)(void *iommu_data);
56 	char *name;
57 	int id;
58 	struct iommu_domain *default_domain;
59 	struct iommu_domain *blocking_domain;
60 	struct iommu_domain *domain;
61 	struct list_head entry;
62 	unsigned int owner_cnt;
63 	void *owner;
64 };
65 
66 struct group_device {
67 	struct list_head list;
68 	struct device *dev;
69 	char *name;
70 };
71 
72 /* Iterate over each struct group_device in a struct iommu_group */
73 #define for_each_group_device(group, pos) \
74 	list_for_each_entry(pos, &(group)->devices, list)
75 
76 struct iommu_group_attribute {
77 	struct attribute attr;
78 	ssize_t (*show)(struct iommu_group *group, char *buf);
79 	ssize_t (*store)(struct iommu_group *group,
80 			 const char *buf, size_t count);
81 };
82 
83 static const char * const iommu_group_resv_type_string[] = {
84 	[IOMMU_RESV_DIRECT]			= "direct",
85 	[IOMMU_RESV_DIRECT_RELAXABLE]		= "direct-relaxable",
86 	[IOMMU_RESV_RESERVED]			= "reserved",
87 	[IOMMU_RESV_MSI]			= "msi",
88 	[IOMMU_RESV_SW_MSI]			= "msi",
89 };
90 
91 #define IOMMU_CMD_LINE_DMA_API		BIT(0)
92 #define IOMMU_CMD_LINE_STRICT		BIT(1)
93 
94 static int bus_iommu_probe(const struct bus_type *bus);
95 static int iommu_bus_notifier(struct notifier_block *nb,
96 			      unsigned long action, void *data);
97 static void iommu_release_device(struct device *dev);
98 static int __iommu_attach_device(struct iommu_domain *domain,
99 				 struct device *dev);
100 static int __iommu_attach_group(struct iommu_domain *domain,
101 				struct iommu_group *group);
102 static struct iommu_domain *__iommu_paging_domain_alloc_flags(struct device *dev,
103 						       unsigned int type,
104 						       unsigned int flags);
105 
106 enum {
107 	IOMMU_SET_DOMAIN_MUST_SUCCEED = 1 << 0,
108 };
109 
110 static int __iommu_device_set_domain(struct iommu_group *group,
111 				     struct device *dev,
112 				     struct iommu_domain *new_domain,
113 				     unsigned int flags);
114 static int __iommu_group_set_domain_internal(struct iommu_group *group,
115 					     struct iommu_domain *new_domain,
116 					     unsigned int flags);
__iommu_group_set_domain(struct iommu_group * group,struct iommu_domain * new_domain)117 static int __iommu_group_set_domain(struct iommu_group *group,
118 				    struct iommu_domain *new_domain)
119 {
120 	return __iommu_group_set_domain_internal(group, new_domain, 0);
121 }
__iommu_group_set_domain_nofail(struct iommu_group * group,struct iommu_domain * new_domain)122 static void __iommu_group_set_domain_nofail(struct iommu_group *group,
123 					    struct iommu_domain *new_domain)
124 {
125 	WARN_ON(__iommu_group_set_domain_internal(
126 		group, new_domain, IOMMU_SET_DOMAIN_MUST_SUCCEED));
127 }
128 
129 static int iommu_setup_default_domain(struct iommu_group *group,
130 				      int target_type);
131 static int iommu_create_device_direct_mappings(struct iommu_domain *domain,
132 					       struct device *dev);
133 static ssize_t iommu_group_store_type(struct iommu_group *group,
134 				      const char *buf, size_t count);
135 static struct group_device *iommu_group_alloc_device(struct iommu_group *group,
136 						     struct device *dev);
137 static void __iommu_group_free_device(struct iommu_group *group,
138 				      struct group_device *grp_dev);
139 static void iommu_domain_init(struct iommu_domain *domain, unsigned int type,
140 			      const struct iommu_ops *ops);
141 
142 #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)		\
143 struct iommu_group_attribute iommu_group_attr_##_name =		\
144 	__ATTR(_name, _mode, _show, _store)
145 
146 #define to_iommu_group_attr(_attr)	\
147 	container_of(_attr, struct iommu_group_attribute, attr)
148 #define to_iommu_group(_kobj)		\
149 	container_of(_kobj, struct iommu_group, kobj)
150 
151 static LIST_HEAD(iommu_device_list);
152 static DEFINE_SPINLOCK(iommu_device_lock);
153 
154 static const struct bus_type * const iommu_buses[] = {
155 	&platform_bus_type,
156 #ifdef CONFIG_PCI
157 	&pci_bus_type,
158 #endif
159 #ifdef CONFIG_ARM_AMBA
160 	&amba_bustype,
161 #endif
162 #ifdef CONFIG_FSL_MC_BUS
163 	&fsl_mc_bus_type,
164 #endif
165 #ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS
166 	&host1x_context_device_bus_type,
167 #endif
168 #ifdef CONFIG_CDX_BUS
169 	&cdx_bus_type,
170 #endif
171 };
172 
173 /*
174  * Use a function instead of an array here because the domain-type is a
175  * bit-field, so an array would waste memory.
176  */
iommu_domain_type_str(unsigned int t)177 static const char *iommu_domain_type_str(unsigned int t)
178 {
179 	switch (t) {
180 	case IOMMU_DOMAIN_BLOCKED:
181 		return "Blocked";
182 	case IOMMU_DOMAIN_IDENTITY:
183 		return "Passthrough";
184 	case IOMMU_DOMAIN_UNMANAGED:
185 		return "Unmanaged";
186 	case IOMMU_DOMAIN_DMA:
187 	case IOMMU_DOMAIN_DMA_FQ:
188 		return "Translated";
189 	case IOMMU_DOMAIN_PLATFORM:
190 		return "Platform";
191 	default:
192 		return "Unknown";
193 	}
194 }
195 
iommu_subsys_init(void)196 static int __init iommu_subsys_init(void)
197 {
198 	struct notifier_block *nb;
199 
200 	if (!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API)) {
201 		if (IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH))
202 			iommu_set_default_passthrough(false);
203 		else
204 			iommu_set_default_translated(false);
205 
206 		if (iommu_default_passthrough() && cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
207 			pr_info("Memory encryption detected - Disabling default IOMMU Passthrough\n");
208 			iommu_set_default_translated(false);
209 		}
210 	}
211 
212 	if (!iommu_default_passthrough() && !iommu_dma_strict)
213 		iommu_def_domain_type = IOMMU_DOMAIN_DMA_FQ;
214 
215 	pr_info("Default domain type: %s%s\n",
216 		iommu_domain_type_str(iommu_def_domain_type),
217 		(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API) ?
218 			" (set via kernel command line)" : "");
219 
220 	if (!iommu_default_passthrough())
221 		pr_info("DMA domain TLB invalidation policy: %s mode%s\n",
222 			iommu_dma_strict ? "strict" : "lazy",
223 			(iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ?
224 				" (set via kernel command line)" : "");
225 
226 	nb = kcalloc(ARRAY_SIZE(iommu_buses), sizeof(*nb), GFP_KERNEL);
227 	if (!nb)
228 		return -ENOMEM;
229 
230 	for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) {
231 		nb[i].notifier_call = iommu_bus_notifier;
232 		bus_register_notifier(iommu_buses[i], &nb[i]);
233 	}
234 
235 	return 0;
236 }
237 subsys_initcall(iommu_subsys_init);
238 
remove_iommu_group(struct device * dev,void * data)239 static int remove_iommu_group(struct device *dev, void *data)
240 {
241 	if (dev->iommu && dev->iommu->iommu_dev == data)
242 		iommu_release_device(dev);
243 
244 	return 0;
245 }
246 
247 /**
248  * iommu_device_register() - Register an IOMMU hardware instance
249  * @iommu: IOMMU handle for the instance
250  * @ops:   IOMMU ops to associate with the instance
251  * @hwdev: (optional) actual instance device, used for fwnode lookup
252  *
253  * Return: 0 on success, or an error.
254  */
iommu_device_register(struct iommu_device * iommu,const struct iommu_ops * ops,struct device * hwdev)255 int iommu_device_register(struct iommu_device *iommu,
256 			  const struct iommu_ops *ops, struct device *hwdev)
257 {
258 	int err = 0;
259 
260 	/* We need to be able to take module references appropriately */
261 	if (WARN_ON(is_module_address((unsigned long)ops) && !ops->owner))
262 		return -EINVAL;
263 
264 	iommu->ops = ops;
265 	if (hwdev)
266 		iommu->fwnode = dev_fwnode(hwdev);
267 
268 	spin_lock(&iommu_device_lock);
269 	list_add_tail(&iommu->list, &iommu_device_list);
270 	spin_unlock(&iommu_device_lock);
271 
272 	for (int i = 0; i < ARRAY_SIZE(iommu_buses) && !err; i++)
273 		err = bus_iommu_probe(iommu_buses[i]);
274 	if (err)
275 		iommu_device_unregister(iommu);
276 	return err;
277 }
278 EXPORT_SYMBOL_GPL(iommu_device_register);
279 
iommu_device_unregister(struct iommu_device * iommu)280 void iommu_device_unregister(struct iommu_device *iommu)
281 {
282 	for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++)
283 		bus_for_each_dev(iommu_buses[i], NULL, iommu, remove_iommu_group);
284 
285 	spin_lock(&iommu_device_lock);
286 	list_del(&iommu->list);
287 	spin_unlock(&iommu_device_lock);
288 
289 	/* Pairs with the alloc in generic_single_device_group() */
290 	iommu_group_put(iommu->singleton_group);
291 	iommu->singleton_group = NULL;
292 }
293 EXPORT_SYMBOL_GPL(iommu_device_unregister);
294 
295 #if IS_ENABLED(CONFIG_IOMMUFD_TEST)
iommu_device_unregister_bus(struct iommu_device * iommu,const struct bus_type * bus,struct notifier_block * nb)296 void iommu_device_unregister_bus(struct iommu_device *iommu,
297 				 const struct bus_type *bus,
298 				 struct notifier_block *nb)
299 {
300 	bus_unregister_notifier(bus, nb);
301 	iommu_device_unregister(iommu);
302 }
303 EXPORT_SYMBOL_GPL(iommu_device_unregister_bus);
304 
305 /*
306  * Register an iommu driver against a single bus. This is only used by iommufd
307  * selftest to create a mock iommu driver. The caller must provide
308  * some memory to hold a notifier_block.
309  */
iommu_device_register_bus(struct iommu_device * iommu,const struct iommu_ops * ops,const struct bus_type * bus,struct notifier_block * nb)310 int iommu_device_register_bus(struct iommu_device *iommu,
311 			      const struct iommu_ops *ops,
312 			      const struct bus_type *bus,
313 			      struct notifier_block *nb)
314 {
315 	int err;
316 
317 	iommu->ops = ops;
318 	nb->notifier_call = iommu_bus_notifier;
319 	err = bus_register_notifier(bus, nb);
320 	if (err)
321 		return err;
322 
323 	spin_lock(&iommu_device_lock);
324 	list_add_tail(&iommu->list, &iommu_device_list);
325 	spin_unlock(&iommu_device_lock);
326 
327 	err = bus_iommu_probe(bus);
328 	if (err) {
329 		iommu_device_unregister_bus(iommu, bus, nb);
330 		return err;
331 	}
332 	return 0;
333 }
334 EXPORT_SYMBOL_GPL(iommu_device_register_bus);
335 #endif
336 
dev_iommu_get(struct device * dev)337 static struct dev_iommu *dev_iommu_get(struct device *dev)
338 {
339 	struct dev_iommu *param = dev->iommu;
340 
341 	lockdep_assert_held(&iommu_probe_device_lock);
342 
343 	if (param)
344 		return param;
345 
346 	param = kzalloc(sizeof(*param), GFP_KERNEL);
347 	if (!param)
348 		return NULL;
349 
350 	mutex_init(&param->lock);
351 	dev->iommu = param;
352 	return param;
353 }
354 
dev_iommu_free(struct device * dev)355 static void dev_iommu_free(struct device *dev)
356 {
357 	struct dev_iommu *param = dev->iommu;
358 
359 	dev->iommu = NULL;
360 	if (param->fwspec) {
361 		fwnode_handle_put(param->fwspec->iommu_fwnode);
362 		kfree(param->fwspec);
363 	}
364 	kfree(param);
365 }
366 
367 /*
368  * Internal equivalent of device_iommu_mapped() for when we care that a device
369  * actually has API ops, and don't want false positives from VFIO-only groups.
370  */
dev_has_iommu(struct device * dev)371 static bool dev_has_iommu(struct device *dev)
372 {
373 	return dev->iommu && dev->iommu->iommu_dev;
374 }
375 
dev_iommu_get_max_pasids(struct device * dev)376 static u32 dev_iommu_get_max_pasids(struct device *dev)
377 {
378 	u32 max_pasids = 0, bits = 0;
379 	int ret;
380 
381 	if (dev_is_pci(dev)) {
382 		ret = pci_max_pasids(to_pci_dev(dev));
383 		if (ret > 0)
384 			max_pasids = ret;
385 	} else {
386 		ret = device_property_read_u32(dev, "pasid-num-bits", &bits);
387 		if (!ret)
388 			max_pasids = 1UL << bits;
389 	}
390 
391 	return min_t(u32, max_pasids, dev->iommu->iommu_dev->max_pasids);
392 }
393 
dev_iommu_priv_set(struct device * dev,void * priv)394 void dev_iommu_priv_set(struct device *dev, void *priv)
395 {
396 	/* FSL_PAMU does something weird */
397 	if (!IS_ENABLED(CONFIG_FSL_PAMU))
398 		lockdep_assert_held(&iommu_probe_device_lock);
399 	dev->iommu->priv = priv;
400 }
401 EXPORT_SYMBOL_GPL(dev_iommu_priv_set);
402 
403 /*
404  * Init the dev->iommu and dev->iommu_group in the struct device and get the
405  * driver probed
406  */
iommu_init_device(struct device * dev,const struct iommu_ops * ops)407 static int iommu_init_device(struct device *dev, const struct iommu_ops *ops)
408 {
409 	struct iommu_device *iommu_dev;
410 	struct iommu_group *group;
411 	int ret;
412 
413 	if (!dev_iommu_get(dev))
414 		return -ENOMEM;
415 
416 	if (!try_module_get(ops->owner)) {
417 		ret = -EINVAL;
418 		goto err_free;
419 	}
420 
421 	iommu_dev = ops->probe_device(dev);
422 	if (IS_ERR(iommu_dev)) {
423 		ret = PTR_ERR(iommu_dev);
424 		goto err_module_put;
425 	}
426 	dev->iommu->iommu_dev = iommu_dev;
427 
428 	ret = iommu_device_link(iommu_dev, dev);
429 	if (ret)
430 		goto err_release;
431 
432 	group = ops->device_group(dev);
433 	if (WARN_ON_ONCE(group == NULL))
434 		group = ERR_PTR(-EINVAL);
435 	if (IS_ERR(group)) {
436 		ret = PTR_ERR(group);
437 		goto err_unlink;
438 	}
439 	dev->iommu_group = group;
440 
441 	dev->iommu->max_pasids = dev_iommu_get_max_pasids(dev);
442 	if (ops->is_attach_deferred)
443 		dev->iommu->attach_deferred = ops->is_attach_deferred(dev);
444 	return 0;
445 
446 err_unlink:
447 	iommu_device_unlink(iommu_dev, dev);
448 err_release:
449 	if (ops->release_device)
450 		ops->release_device(dev);
451 err_module_put:
452 	module_put(ops->owner);
453 err_free:
454 	dev->iommu->iommu_dev = NULL;
455 	dev_iommu_free(dev);
456 	return ret;
457 }
458 
iommu_deinit_device(struct device * dev)459 static void iommu_deinit_device(struct device *dev)
460 {
461 	struct iommu_group *group = dev->iommu_group;
462 	const struct iommu_ops *ops = dev_iommu_ops(dev);
463 
464 	lockdep_assert_held(&group->mutex);
465 
466 	iommu_device_unlink(dev->iommu->iommu_dev, dev);
467 
468 	/*
469 	 * release_device() must stop using any attached domain on the device.
470 	 * If there are still other devices in the group, they are not affected
471 	 * by this callback.
472 	 *
473 	 * If the iommu driver provides release_domain, the core code ensures
474 	 * that domain is attached prior to calling release_device. Drivers can
475 	 * use this to enforce a translation on the idle iommu. Typically, the
476 	 * global static blocked_domain is a good choice.
477 	 *
478 	 * Otherwise, the iommu driver must set the device to either an identity
479 	 * or a blocking translation in release_device() and stop using any
480 	 * domain pointer, as it is going to be freed.
481 	 *
482 	 * Regardless, if a delayed attach never occurred, then the release
483 	 * should still avoid touching any hardware configuration either.
484 	 */
485 	if (!dev->iommu->attach_deferred && ops->release_domain)
486 		ops->release_domain->ops->attach_dev(ops->release_domain, dev);
487 
488 	if (ops->release_device)
489 		ops->release_device(dev);
490 
491 	/*
492 	 * If this is the last driver to use the group then we must free the
493 	 * domains before we do the module_put().
494 	 */
495 	if (list_empty(&group->devices)) {
496 		if (group->default_domain) {
497 			iommu_domain_free(group->default_domain);
498 			group->default_domain = NULL;
499 		}
500 		if (group->blocking_domain) {
501 			iommu_domain_free(group->blocking_domain);
502 			group->blocking_domain = NULL;
503 		}
504 		group->domain = NULL;
505 	}
506 
507 	/* Caller must put iommu_group */
508 	dev->iommu_group = NULL;
509 	module_put(ops->owner);
510 	dev_iommu_free(dev);
511 }
512 
513 DEFINE_MUTEX(iommu_probe_device_lock);
514 
__iommu_probe_device(struct device * dev,struct list_head * group_list)515 static int __iommu_probe_device(struct device *dev, struct list_head *group_list)
516 {
517 	const struct iommu_ops *ops;
518 	struct iommu_group *group;
519 	struct group_device *gdev;
520 	int ret;
521 
522 	/*
523 	 * For FDT-based systems and ACPI IORT/VIOT, drivers register IOMMU
524 	 * instances with non-NULL fwnodes, and client devices should have been
525 	 * identified with a fwspec by this point. Otherwise, we can currently
526 	 * assume that only one of Intel, AMD, s390, PAMU or legacy SMMUv2 can
527 	 * be present, and that any of their registered instances has suitable
528 	 * ops for probing, and thus cheekily co-opt the same mechanism.
529 	 */
530 	ops = iommu_fwspec_ops(dev_iommu_fwspec_get(dev));
531 	if (!ops)
532 		return -ENODEV;
533 	/*
534 	 * Serialise to avoid races between IOMMU drivers registering in
535 	 * parallel and/or the "replay" calls from ACPI/OF code via client
536 	 * driver probe. Once the latter have been cleaned up we should
537 	 * probably be able to use device_lock() here to minimise the scope,
538 	 * but for now enforcing a simple global ordering is fine.
539 	 */
540 	lockdep_assert_held(&iommu_probe_device_lock);
541 
542 	/* Device is probed already if in a group */
543 	if (dev->iommu_group)
544 		return 0;
545 
546 	ret = iommu_init_device(dev, ops);
547 	if (ret)
548 		return ret;
549 
550 	group = dev->iommu_group;
551 	gdev = iommu_group_alloc_device(group, dev);
552 	mutex_lock(&group->mutex);
553 	if (IS_ERR(gdev)) {
554 		ret = PTR_ERR(gdev);
555 		goto err_put_group;
556 	}
557 
558 	/*
559 	 * The gdev must be in the list before calling
560 	 * iommu_setup_default_domain()
561 	 */
562 	list_add_tail(&gdev->list, &group->devices);
563 	WARN_ON(group->default_domain && !group->domain);
564 	if (group->default_domain)
565 		iommu_create_device_direct_mappings(group->default_domain, dev);
566 	if (group->domain) {
567 		ret = __iommu_device_set_domain(group, dev, group->domain, 0);
568 		if (ret)
569 			goto err_remove_gdev;
570 	} else if (!group->default_domain && !group_list) {
571 		ret = iommu_setup_default_domain(group, 0);
572 		if (ret)
573 			goto err_remove_gdev;
574 	} else if (!group->default_domain) {
575 		/*
576 		 * With a group_list argument we defer the default_domain setup
577 		 * to the caller by providing a de-duplicated list of groups
578 		 * that need further setup.
579 		 */
580 		if (list_empty(&group->entry))
581 			list_add_tail(&group->entry, group_list);
582 	}
583 
584 	if (group->default_domain)
585 		iommu_setup_dma_ops(dev);
586 
587 	mutex_unlock(&group->mutex);
588 
589 	return 0;
590 
591 err_remove_gdev:
592 	list_del(&gdev->list);
593 	__iommu_group_free_device(group, gdev);
594 err_put_group:
595 	iommu_deinit_device(dev);
596 	mutex_unlock(&group->mutex);
597 	iommu_group_put(group);
598 
599 	return ret;
600 }
601 
iommu_probe_device(struct device * dev)602 int iommu_probe_device(struct device *dev)
603 {
604 	const struct iommu_ops *ops;
605 	int ret;
606 
607 	mutex_lock(&iommu_probe_device_lock);
608 	ret = __iommu_probe_device(dev, NULL);
609 	mutex_unlock(&iommu_probe_device_lock);
610 	if (ret)
611 		return ret;
612 
613 	ops = dev_iommu_ops(dev);
614 	if (ops->probe_finalize)
615 		ops->probe_finalize(dev);
616 
617 	return 0;
618 }
619 
__iommu_group_free_device(struct iommu_group * group,struct group_device * grp_dev)620 static void __iommu_group_free_device(struct iommu_group *group,
621 				      struct group_device *grp_dev)
622 {
623 	struct device *dev = grp_dev->dev;
624 
625 	sysfs_remove_link(group->devices_kobj, grp_dev->name);
626 	sysfs_remove_link(&dev->kobj, "iommu_group");
627 
628 	trace_remove_device_from_group(group->id, dev);
629 
630 	/*
631 	 * If the group has become empty then ownership must have been
632 	 * released, and the current domain must be set back to NULL or
633 	 * the default domain.
634 	 */
635 	if (list_empty(&group->devices))
636 		WARN_ON(group->owner_cnt ||
637 			group->domain != group->default_domain);
638 
639 	kfree(grp_dev->name);
640 	kfree(grp_dev);
641 }
642 
643 /* Remove the iommu_group from the struct device. */
__iommu_group_remove_device(struct device * dev)644 static void __iommu_group_remove_device(struct device *dev)
645 {
646 	struct iommu_group *group = dev->iommu_group;
647 	struct group_device *device;
648 
649 	mutex_lock(&group->mutex);
650 	for_each_group_device(group, device) {
651 		if (device->dev != dev)
652 			continue;
653 
654 		list_del(&device->list);
655 		__iommu_group_free_device(group, device);
656 		if (dev_has_iommu(dev))
657 			iommu_deinit_device(dev);
658 		else
659 			dev->iommu_group = NULL;
660 		break;
661 	}
662 	mutex_unlock(&group->mutex);
663 
664 	/*
665 	 * Pairs with the get in iommu_init_device() or
666 	 * iommu_group_add_device()
667 	 */
668 	iommu_group_put(group);
669 }
670 
iommu_release_device(struct device * dev)671 static void iommu_release_device(struct device *dev)
672 {
673 	struct iommu_group *group = dev->iommu_group;
674 
675 	if (group)
676 		__iommu_group_remove_device(dev);
677 
678 	/* Free any fwspec if no iommu_driver was ever attached */
679 	if (dev->iommu)
680 		dev_iommu_free(dev);
681 }
682 
iommu_set_def_domain_type(char * str)683 static int __init iommu_set_def_domain_type(char *str)
684 {
685 	bool pt;
686 	int ret;
687 
688 	ret = kstrtobool(str, &pt);
689 	if (ret)
690 		return ret;
691 
692 	if (pt)
693 		iommu_set_default_passthrough(true);
694 	else
695 		iommu_set_default_translated(true);
696 
697 	return 0;
698 }
699 early_param("iommu.passthrough", iommu_set_def_domain_type);
700 
iommu_dma_setup(char * str)701 static int __init iommu_dma_setup(char *str)
702 {
703 	int ret = kstrtobool(str, &iommu_dma_strict);
704 
705 	if (!ret)
706 		iommu_cmd_line |= IOMMU_CMD_LINE_STRICT;
707 	return ret;
708 }
709 early_param("iommu.strict", iommu_dma_setup);
710 
iommu_set_dma_strict(void)711 void iommu_set_dma_strict(void)
712 {
713 	iommu_dma_strict = true;
714 	if (iommu_def_domain_type == IOMMU_DOMAIN_DMA_FQ)
715 		iommu_def_domain_type = IOMMU_DOMAIN_DMA;
716 }
717 
iommu_group_attr_show(struct kobject * kobj,struct attribute * __attr,char * buf)718 static ssize_t iommu_group_attr_show(struct kobject *kobj,
719 				     struct attribute *__attr, char *buf)
720 {
721 	struct iommu_group_attribute *attr = to_iommu_group_attr(__attr);
722 	struct iommu_group *group = to_iommu_group(kobj);
723 	ssize_t ret = -EIO;
724 
725 	if (attr->show)
726 		ret = attr->show(group, buf);
727 	return ret;
728 }
729 
iommu_group_attr_store(struct kobject * kobj,struct attribute * __attr,const char * buf,size_t count)730 static ssize_t iommu_group_attr_store(struct kobject *kobj,
731 				      struct attribute *__attr,
732 				      const char *buf, size_t count)
733 {
734 	struct iommu_group_attribute *attr = to_iommu_group_attr(__attr);
735 	struct iommu_group *group = to_iommu_group(kobj);
736 	ssize_t ret = -EIO;
737 
738 	if (attr->store)
739 		ret = attr->store(group, buf, count);
740 	return ret;
741 }
742 
743 static const struct sysfs_ops iommu_group_sysfs_ops = {
744 	.show = iommu_group_attr_show,
745 	.store = iommu_group_attr_store,
746 };
747 
iommu_group_create_file(struct iommu_group * group,struct iommu_group_attribute * attr)748 static int iommu_group_create_file(struct iommu_group *group,
749 				   struct iommu_group_attribute *attr)
750 {
751 	return sysfs_create_file(&group->kobj, &attr->attr);
752 }
753 
iommu_group_remove_file(struct iommu_group * group,struct iommu_group_attribute * attr)754 static void iommu_group_remove_file(struct iommu_group *group,
755 				    struct iommu_group_attribute *attr)
756 {
757 	sysfs_remove_file(&group->kobj, &attr->attr);
758 }
759 
iommu_group_show_name(struct iommu_group * group,char * buf)760 static ssize_t iommu_group_show_name(struct iommu_group *group, char *buf)
761 {
762 	return sysfs_emit(buf, "%s\n", group->name);
763 }
764 
765 /**
766  * iommu_insert_resv_region - Insert a new region in the
767  * list of reserved regions.
768  * @new: new region to insert
769  * @regions: list of regions
770  *
771  * Elements are sorted by start address and overlapping segments
772  * of the same type are merged.
773  */
iommu_insert_resv_region(struct iommu_resv_region * new,struct list_head * regions)774 static int iommu_insert_resv_region(struct iommu_resv_region *new,
775 				    struct list_head *regions)
776 {
777 	struct iommu_resv_region *iter, *tmp, *nr, *top;
778 	LIST_HEAD(stack);
779 
780 	nr = iommu_alloc_resv_region(new->start, new->length,
781 				     new->prot, new->type, GFP_KERNEL);
782 	if (!nr)
783 		return -ENOMEM;
784 
785 	/* First add the new element based on start address sorting */
786 	list_for_each_entry(iter, regions, list) {
787 		if (nr->start < iter->start ||
788 		    (nr->start == iter->start && nr->type <= iter->type))
789 			break;
790 	}
791 	list_add_tail(&nr->list, &iter->list);
792 
793 	/* Merge overlapping segments of type nr->type in @regions, if any */
794 	list_for_each_entry_safe(iter, tmp, regions, list) {
795 		phys_addr_t top_end, iter_end = iter->start + iter->length - 1;
796 
797 		/* no merge needed on elements of different types than @new */
798 		if (iter->type != new->type) {
799 			list_move_tail(&iter->list, &stack);
800 			continue;
801 		}
802 
803 		/* look for the last stack element of same type as @iter */
804 		list_for_each_entry_reverse(top, &stack, list)
805 			if (top->type == iter->type)
806 				goto check_overlap;
807 
808 		list_move_tail(&iter->list, &stack);
809 		continue;
810 
811 check_overlap:
812 		top_end = top->start + top->length - 1;
813 
814 		if (iter->start > top_end + 1) {
815 			list_move_tail(&iter->list, &stack);
816 		} else {
817 			top->length = max(top_end, iter_end) - top->start + 1;
818 			list_del(&iter->list);
819 			kfree(iter);
820 		}
821 	}
822 	list_splice(&stack, regions);
823 	return 0;
824 }
825 
826 static int
iommu_insert_device_resv_regions(struct list_head * dev_resv_regions,struct list_head * group_resv_regions)827 iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
828 				 struct list_head *group_resv_regions)
829 {
830 	struct iommu_resv_region *entry;
831 	int ret = 0;
832 
833 	list_for_each_entry(entry, dev_resv_regions, list) {
834 		ret = iommu_insert_resv_region(entry, group_resv_regions);
835 		if (ret)
836 			break;
837 	}
838 	return ret;
839 }
840 
iommu_get_group_resv_regions(struct iommu_group * group,struct list_head * head)841 int iommu_get_group_resv_regions(struct iommu_group *group,
842 				 struct list_head *head)
843 {
844 	struct group_device *device;
845 	int ret = 0;
846 
847 	mutex_lock(&group->mutex);
848 	for_each_group_device(group, device) {
849 		struct list_head dev_resv_regions;
850 
851 		/*
852 		 * Non-API groups still expose reserved_regions in sysfs,
853 		 * so filter out calls that get here that way.
854 		 */
855 		if (!dev_has_iommu(device->dev))
856 			break;
857 
858 		INIT_LIST_HEAD(&dev_resv_regions);
859 		iommu_get_resv_regions(device->dev, &dev_resv_regions);
860 		ret = iommu_insert_device_resv_regions(&dev_resv_regions, head);
861 		iommu_put_resv_regions(device->dev, &dev_resv_regions);
862 		if (ret)
863 			break;
864 	}
865 	mutex_unlock(&group->mutex);
866 	return ret;
867 }
868 EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions);
869 
iommu_group_show_resv_regions(struct iommu_group * group,char * buf)870 static ssize_t iommu_group_show_resv_regions(struct iommu_group *group,
871 					     char *buf)
872 {
873 	struct iommu_resv_region *region, *next;
874 	struct list_head group_resv_regions;
875 	int offset = 0;
876 
877 	INIT_LIST_HEAD(&group_resv_regions);
878 	iommu_get_group_resv_regions(group, &group_resv_regions);
879 
880 	list_for_each_entry_safe(region, next, &group_resv_regions, list) {
881 		offset += sysfs_emit_at(buf, offset, "0x%016llx 0x%016llx %s\n",
882 					(long long)region->start,
883 					(long long)(region->start +
884 						    region->length - 1),
885 					iommu_group_resv_type_string[region->type]);
886 		kfree(region);
887 	}
888 
889 	return offset;
890 }
891 
iommu_group_show_type(struct iommu_group * group,char * buf)892 static ssize_t iommu_group_show_type(struct iommu_group *group,
893 				     char *buf)
894 {
895 	char *type = "unknown";
896 
897 	mutex_lock(&group->mutex);
898 	if (group->default_domain) {
899 		switch (group->default_domain->type) {
900 		case IOMMU_DOMAIN_BLOCKED:
901 			type = "blocked";
902 			break;
903 		case IOMMU_DOMAIN_IDENTITY:
904 			type = "identity";
905 			break;
906 		case IOMMU_DOMAIN_UNMANAGED:
907 			type = "unmanaged";
908 			break;
909 		case IOMMU_DOMAIN_DMA:
910 			type = "DMA";
911 			break;
912 		case IOMMU_DOMAIN_DMA_FQ:
913 			type = "DMA-FQ";
914 			break;
915 		}
916 	}
917 	mutex_unlock(&group->mutex);
918 
919 	return sysfs_emit(buf, "%s\n", type);
920 }
921 
922 static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
923 
924 static IOMMU_GROUP_ATTR(reserved_regions, 0444,
925 			iommu_group_show_resv_regions, NULL);
926 
927 static IOMMU_GROUP_ATTR(type, 0644, iommu_group_show_type,
928 			iommu_group_store_type);
929 
iommu_group_release(struct kobject * kobj)930 static void iommu_group_release(struct kobject *kobj)
931 {
932 	struct iommu_group *group = to_iommu_group(kobj);
933 
934 	pr_debug("Releasing group %d\n", group->id);
935 
936 	if (group->iommu_data_release)
937 		group->iommu_data_release(group->iommu_data);
938 
939 	ida_free(&iommu_group_ida, group->id);
940 
941 	/* Domains are free'd by iommu_deinit_device() */
942 	WARN_ON(group->default_domain);
943 	WARN_ON(group->blocking_domain);
944 
945 	kfree(group->name);
946 	kfree(group);
947 }
948 
949 static const struct kobj_type iommu_group_ktype = {
950 	.sysfs_ops = &iommu_group_sysfs_ops,
951 	.release = iommu_group_release,
952 };
953 
954 /**
955  * iommu_group_alloc - Allocate a new group
956  *
957  * This function is called by an iommu driver to allocate a new iommu
958  * group.  The iommu group represents the minimum granularity of the iommu.
959  * Upon successful return, the caller holds a reference to the supplied
960  * group in order to hold the group until devices are added.  Use
961  * iommu_group_put() to release this extra reference count, allowing the
962  * group to be automatically reclaimed once it has no devices or external
963  * references.
964  */
iommu_group_alloc(void)965 struct iommu_group *iommu_group_alloc(void)
966 {
967 	struct iommu_group *group;
968 	int ret;
969 
970 	group = kzalloc(sizeof(*group), GFP_KERNEL);
971 	if (!group)
972 		return ERR_PTR(-ENOMEM);
973 
974 	group->kobj.kset = iommu_group_kset;
975 	mutex_init(&group->mutex);
976 	INIT_LIST_HEAD(&group->devices);
977 	INIT_LIST_HEAD(&group->entry);
978 	xa_init(&group->pasid_array);
979 
980 	ret = ida_alloc(&iommu_group_ida, GFP_KERNEL);
981 	if (ret < 0) {
982 		kfree(group);
983 		return ERR_PTR(ret);
984 	}
985 	group->id = ret;
986 
987 	ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype,
988 				   NULL, "%d", group->id);
989 	if (ret) {
990 		kobject_put(&group->kobj);
991 		return ERR_PTR(ret);
992 	}
993 
994 	group->devices_kobj = kobject_create_and_add("devices", &group->kobj);
995 	if (!group->devices_kobj) {
996 		kobject_put(&group->kobj); /* triggers .release & free */
997 		return ERR_PTR(-ENOMEM);
998 	}
999 
1000 	/*
1001 	 * The devices_kobj holds a reference on the group kobject, so
1002 	 * as long as that exists so will the group.  We can therefore
1003 	 * use the devices_kobj for reference counting.
1004 	 */
1005 	kobject_put(&group->kobj);
1006 
1007 	ret = iommu_group_create_file(group,
1008 				      &iommu_group_attr_reserved_regions);
1009 	if (ret) {
1010 		kobject_put(group->devices_kobj);
1011 		return ERR_PTR(ret);
1012 	}
1013 
1014 	ret = iommu_group_create_file(group, &iommu_group_attr_type);
1015 	if (ret) {
1016 		kobject_put(group->devices_kobj);
1017 		return ERR_PTR(ret);
1018 	}
1019 
1020 	pr_debug("Allocated group %d\n", group->id);
1021 
1022 	return group;
1023 }
1024 EXPORT_SYMBOL_GPL(iommu_group_alloc);
1025 
1026 /**
1027  * iommu_group_get_iommudata - retrieve iommu_data registered for a group
1028  * @group: the group
1029  *
1030  * iommu drivers can store data in the group for use when doing iommu
1031  * operations.  This function provides a way to retrieve it.  Caller
1032  * should hold a group reference.
1033  */
iommu_group_get_iommudata(struct iommu_group * group)1034 void *iommu_group_get_iommudata(struct iommu_group *group)
1035 {
1036 	return group->iommu_data;
1037 }
1038 EXPORT_SYMBOL_GPL(iommu_group_get_iommudata);
1039 
1040 /**
1041  * iommu_group_set_iommudata - set iommu_data for a group
1042  * @group: the group
1043  * @iommu_data: new data
1044  * @release: release function for iommu_data
1045  *
1046  * iommu drivers can store data in the group for use when doing iommu
1047  * operations.  This function provides a way to set the data after
1048  * the group has been allocated.  Caller should hold a group reference.
1049  */
iommu_group_set_iommudata(struct iommu_group * group,void * iommu_data,void (* release)(void * iommu_data))1050 void iommu_group_set_iommudata(struct iommu_group *group, void *iommu_data,
1051 			       void (*release)(void *iommu_data))
1052 {
1053 	group->iommu_data = iommu_data;
1054 	group->iommu_data_release = release;
1055 }
1056 EXPORT_SYMBOL_GPL(iommu_group_set_iommudata);
1057 
1058 /**
1059  * iommu_group_set_name - set name for a group
1060  * @group: the group
1061  * @name: name
1062  *
1063  * Allow iommu driver to set a name for a group.  When set it will
1064  * appear in a name attribute file under the group in sysfs.
1065  */
iommu_group_set_name(struct iommu_group * group,const char * name)1066 int iommu_group_set_name(struct iommu_group *group, const char *name)
1067 {
1068 	int ret;
1069 
1070 	if (group->name) {
1071 		iommu_group_remove_file(group, &iommu_group_attr_name);
1072 		kfree(group->name);
1073 		group->name = NULL;
1074 		if (!name)
1075 			return 0;
1076 	}
1077 
1078 	group->name = kstrdup(name, GFP_KERNEL);
1079 	if (!group->name)
1080 		return -ENOMEM;
1081 
1082 	ret = iommu_group_create_file(group, &iommu_group_attr_name);
1083 	if (ret) {
1084 		kfree(group->name);
1085 		group->name = NULL;
1086 		return ret;
1087 	}
1088 
1089 	return 0;
1090 }
1091 EXPORT_SYMBOL_GPL(iommu_group_set_name);
1092 
iommu_create_device_direct_mappings(struct iommu_domain * domain,struct device * dev)1093 static int iommu_create_device_direct_mappings(struct iommu_domain *domain,
1094 					       struct device *dev)
1095 {
1096 	struct iommu_resv_region *entry;
1097 	struct list_head mappings;
1098 	unsigned long pg_size;
1099 	int ret = 0;
1100 
1101 	pg_size = domain->pgsize_bitmap ? 1UL << __ffs(domain->pgsize_bitmap) : 0;
1102 	INIT_LIST_HEAD(&mappings);
1103 
1104 	if (WARN_ON_ONCE(iommu_is_dma_domain(domain) && !pg_size))
1105 		return -EINVAL;
1106 
1107 	iommu_get_resv_regions(dev, &mappings);
1108 
1109 	/* We need to consider overlapping regions for different devices */
1110 	list_for_each_entry(entry, &mappings, list) {
1111 		dma_addr_t start, end, addr;
1112 		size_t map_size = 0;
1113 
1114 		if (entry->type == IOMMU_RESV_DIRECT)
1115 			dev->iommu->require_direct = 1;
1116 
1117 		if ((entry->type != IOMMU_RESV_DIRECT &&
1118 		     entry->type != IOMMU_RESV_DIRECT_RELAXABLE) ||
1119 		    !iommu_is_dma_domain(domain))
1120 			continue;
1121 
1122 		start = ALIGN(entry->start, pg_size);
1123 		end   = ALIGN(entry->start + entry->length, pg_size);
1124 
1125 		for (addr = start; addr <= end; addr += pg_size) {
1126 			phys_addr_t phys_addr;
1127 
1128 			if (addr == end)
1129 				goto map_end;
1130 
1131 			phys_addr = iommu_iova_to_phys(domain, addr);
1132 			if (!phys_addr) {
1133 				map_size += pg_size;
1134 				continue;
1135 			}
1136 
1137 map_end:
1138 			if (map_size) {
1139 				ret = iommu_map(domain, addr - map_size,
1140 						addr - map_size, map_size,
1141 						entry->prot, GFP_KERNEL);
1142 				if (ret)
1143 					goto out;
1144 				map_size = 0;
1145 			}
1146 		}
1147 
1148 	}
1149 out:
1150 	iommu_put_resv_regions(dev, &mappings);
1151 
1152 	return ret;
1153 }
1154 
1155 /* This is undone by __iommu_group_free_device() */
iommu_group_alloc_device(struct iommu_group * group,struct device * dev)1156 static struct group_device *iommu_group_alloc_device(struct iommu_group *group,
1157 						     struct device *dev)
1158 {
1159 	int ret, i = 0;
1160 	struct group_device *device;
1161 
1162 	device = kzalloc(sizeof(*device), GFP_KERNEL);
1163 	if (!device)
1164 		return ERR_PTR(-ENOMEM);
1165 
1166 	device->dev = dev;
1167 
1168 	ret = sysfs_create_link(&dev->kobj, &group->kobj, "iommu_group");
1169 	if (ret)
1170 		goto err_free_device;
1171 
1172 	device->name = kasprintf(GFP_KERNEL, "%s", kobject_name(&dev->kobj));
1173 rename:
1174 	if (!device->name) {
1175 		ret = -ENOMEM;
1176 		goto err_remove_link;
1177 	}
1178 
1179 	ret = sysfs_create_link_nowarn(group->devices_kobj,
1180 				       &dev->kobj, device->name);
1181 	if (ret) {
1182 		if (ret == -EEXIST && i >= 0) {
1183 			/*
1184 			 * Account for the slim chance of collision
1185 			 * and append an instance to the name.
1186 			 */
1187 			kfree(device->name);
1188 			device->name = kasprintf(GFP_KERNEL, "%s.%d",
1189 						 kobject_name(&dev->kobj), i++);
1190 			goto rename;
1191 		}
1192 		goto err_free_name;
1193 	}
1194 
1195 	trace_add_device_to_group(group->id, dev);
1196 
1197 	dev_info(dev, "Adding to iommu group %d\n", group->id);
1198 
1199 	return device;
1200 
1201 err_free_name:
1202 	kfree(device->name);
1203 err_remove_link:
1204 	sysfs_remove_link(&dev->kobj, "iommu_group");
1205 err_free_device:
1206 	kfree(device);
1207 	dev_err(dev, "Failed to add to iommu group %d: %d\n", group->id, ret);
1208 	return ERR_PTR(ret);
1209 }
1210 
1211 /**
1212  * iommu_group_add_device - add a device to an iommu group
1213  * @group: the group into which to add the device (reference should be held)
1214  * @dev: the device
1215  *
1216  * This function is called by an iommu driver to add a device into a
1217  * group.  Adding a device increments the group reference count.
1218  */
iommu_group_add_device(struct iommu_group * group,struct device * dev)1219 int iommu_group_add_device(struct iommu_group *group, struct device *dev)
1220 {
1221 	struct group_device *gdev;
1222 
1223 	gdev = iommu_group_alloc_device(group, dev);
1224 	if (IS_ERR(gdev))
1225 		return PTR_ERR(gdev);
1226 
1227 	iommu_group_ref_get(group);
1228 	dev->iommu_group = group;
1229 
1230 	mutex_lock(&group->mutex);
1231 	list_add_tail(&gdev->list, &group->devices);
1232 	mutex_unlock(&group->mutex);
1233 	return 0;
1234 }
1235 EXPORT_SYMBOL_GPL(iommu_group_add_device);
1236 
1237 /**
1238  * iommu_group_remove_device - remove a device from it's current group
1239  * @dev: device to be removed
1240  *
1241  * This function is called by an iommu driver to remove the device from
1242  * it's current group.  This decrements the iommu group reference count.
1243  */
iommu_group_remove_device(struct device * dev)1244 void iommu_group_remove_device(struct device *dev)
1245 {
1246 	struct iommu_group *group = dev->iommu_group;
1247 
1248 	if (!group)
1249 		return;
1250 
1251 	dev_info(dev, "Removing from iommu group %d\n", group->id);
1252 
1253 	__iommu_group_remove_device(dev);
1254 }
1255 EXPORT_SYMBOL_GPL(iommu_group_remove_device);
1256 
1257 #if IS_ENABLED(CONFIG_LOCKDEP) && IS_ENABLED(CONFIG_IOMMU_API)
1258 /**
1259  * iommu_group_mutex_assert - Check device group mutex lock
1260  * @dev: the device that has group param set
1261  *
1262  * This function is called by an iommu driver to check whether it holds
1263  * group mutex lock for the given device or not.
1264  *
1265  * Note that this function must be called after device group param is set.
1266  */
iommu_group_mutex_assert(struct device * dev)1267 void iommu_group_mutex_assert(struct device *dev)
1268 {
1269 	struct iommu_group *group = dev->iommu_group;
1270 
1271 	lockdep_assert_held(&group->mutex);
1272 }
1273 EXPORT_SYMBOL_GPL(iommu_group_mutex_assert);
1274 #endif
1275 
iommu_group_first_dev(struct iommu_group * group)1276 static struct device *iommu_group_first_dev(struct iommu_group *group)
1277 {
1278 	lockdep_assert_held(&group->mutex);
1279 	return list_first_entry(&group->devices, struct group_device, list)->dev;
1280 }
1281 
1282 /**
1283  * iommu_group_for_each_dev - iterate over each device in the group
1284  * @group: the group
1285  * @data: caller opaque data to be passed to callback function
1286  * @fn: caller supplied callback function
1287  *
1288  * This function is called by group users to iterate over group devices.
1289  * Callers should hold a reference count to the group during callback.
1290  * The group->mutex is held across callbacks, which will block calls to
1291  * iommu_group_add/remove_device.
1292  */
iommu_group_for_each_dev(struct iommu_group * group,void * data,int (* fn)(struct device *,void *))1293 int iommu_group_for_each_dev(struct iommu_group *group, void *data,
1294 			     int (*fn)(struct device *, void *))
1295 {
1296 	struct group_device *device;
1297 	int ret = 0;
1298 
1299 	mutex_lock(&group->mutex);
1300 	for_each_group_device(group, device) {
1301 		ret = fn(device->dev, data);
1302 		if (ret)
1303 			break;
1304 	}
1305 	mutex_unlock(&group->mutex);
1306 
1307 	return ret;
1308 }
1309 EXPORT_SYMBOL_GPL(iommu_group_for_each_dev);
1310 
1311 /**
1312  * iommu_group_get - Return the group for a device and increment reference
1313  * @dev: get the group that this device belongs to
1314  *
1315  * This function is called by iommu drivers and users to get the group
1316  * for the specified device.  If found, the group is returned and the group
1317  * reference in incremented, else NULL.
1318  */
iommu_group_get(struct device * dev)1319 struct iommu_group *iommu_group_get(struct device *dev)
1320 {
1321 	struct iommu_group *group = dev->iommu_group;
1322 
1323 	if (group)
1324 		kobject_get(group->devices_kobj);
1325 
1326 	return group;
1327 }
1328 EXPORT_SYMBOL_GPL(iommu_group_get);
1329 
1330 /**
1331  * iommu_group_ref_get - Increment reference on a group
1332  * @group: the group to use, must not be NULL
1333  *
1334  * This function is called by iommu drivers to take additional references on an
1335  * existing group.  Returns the given group for convenience.
1336  */
iommu_group_ref_get(struct iommu_group * group)1337 struct iommu_group *iommu_group_ref_get(struct iommu_group *group)
1338 {
1339 	kobject_get(group->devices_kobj);
1340 	return group;
1341 }
1342 EXPORT_SYMBOL_GPL(iommu_group_ref_get);
1343 
1344 /**
1345  * iommu_group_put - Decrement group reference
1346  * @group: the group to use
1347  *
1348  * This function is called by iommu drivers and users to release the
1349  * iommu group.  Once the reference count is zero, the group is released.
1350  */
iommu_group_put(struct iommu_group * group)1351 void iommu_group_put(struct iommu_group *group)
1352 {
1353 	if (group)
1354 		kobject_put(group->devices_kobj);
1355 }
1356 EXPORT_SYMBOL_GPL(iommu_group_put);
1357 
1358 /**
1359  * iommu_group_id - Return ID for a group
1360  * @group: the group to ID
1361  *
1362  * Return the unique ID for the group matching the sysfs group number.
1363  */
iommu_group_id(struct iommu_group * group)1364 int iommu_group_id(struct iommu_group *group)
1365 {
1366 	return group->id;
1367 }
1368 EXPORT_SYMBOL_GPL(iommu_group_id);
1369 
1370 static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev,
1371 					       unsigned long *devfns);
1372 
1373 /*
1374  * To consider a PCI device isolated, we require ACS to support Source
1375  * Validation, Request Redirection, Completer Redirection, and Upstream
1376  * Forwarding.  This effectively means that devices cannot spoof their
1377  * requester ID, requests and completions cannot be redirected, and all
1378  * transactions are forwarded upstream, even as it passes through a
1379  * bridge where the target device is downstream.
1380  */
1381 #define REQ_ACS_FLAGS   (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
1382 
1383 /*
1384  * For multifunction devices which are not isolated from each other, find
1385  * all the other non-isolated functions and look for existing groups.  For
1386  * each function, we also need to look for aliases to or from other devices
1387  * that may already have a group.
1388  */
get_pci_function_alias_group(struct pci_dev * pdev,unsigned long * devfns)1389 static struct iommu_group *get_pci_function_alias_group(struct pci_dev *pdev,
1390 							unsigned long *devfns)
1391 {
1392 	struct pci_dev *tmp = NULL;
1393 	struct iommu_group *group;
1394 
1395 	if (!pdev->multifunction || pci_acs_enabled(pdev, REQ_ACS_FLAGS))
1396 		return NULL;
1397 
1398 	for_each_pci_dev(tmp) {
1399 		if (tmp == pdev || tmp->bus != pdev->bus ||
1400 		    PCI_SLOT(tmp->devfn) != PCI_SLOT(pdev->devfn) ||
1401 		    pci_acs_enabled(tmp, REQ_ACS_FLAGS))
1402 			continue;
1403 
1404 		group = get_pci_alias_group(tmp, devfns);
1405 		if (group) {
1406 			pci_dev_put(tmp);
1407 			return group;
1408 		}
1409 	}
1410 
1411 	return NULL;
1412 }
1413 
1414 /*
1415  * Look for aliases to or from the given device for existing groups. DMA
1416  * aliases are only supported on the same bus, therefore the search
1417  * space is quite small (especially since we're really only looking at pcie
1418  * device, and therefore only expect multiple slots on the root complex or
1419  * downstream switch ports).  It's conceivable though that a pair of
1420  * multifunction devices could have aliases between them that would cause a
1421  * loop.  To prevent this, we use a bitmap to track where we've been.
1422  */
get_pci_alias_group(struct pci_dev * pdev,unsigned long * devfns)1423 static struct iommu_group *get_pci_alias_group(struct pci_dev *pdev,
1424 					       unsigned long *devfns)
1425 {
1426 	struct pci_dev *tmp = NULL;
1427 	struct iommu_group *group;
1428 
1429 	if (test_and_set_bit(pdev->devfn & 0xff, devfns))
1430 		return NULL;
1431 
1432 	group = iommu_group_get(&pdev->dev);
1433 	if (group)
1434 		return group;
1435 
1436 	for_each_pci_dev(tmp) {
1437 		if (tmp == pdev || tmp->bus != pdev->bus)
1438 			continue;
1439 
1440 		/* We alias them or they alias us */
1441 		if (pci_devs_are_dma_aliases(pdev, tmp)) {
1442 			group = get_pci_alias_group(tmp, devfns);
1443 			if (group) {
1444 				pci_dev_put(tmp);
1445 				return group;
1446 			}
1447 
1448 			group = get_pci_function_alias_group(tmp, devfns);
1449 			if (group) {
1450 				pci_dev_put(tmp);
1451 				return group;
1452 			}
1453 		}
1454 	}
1455 
1456 	return NULL;
1457 }
1458 
1459 struct group_for_pci_data {
1460 	struct pci_dev *pdev;
1461 	struct iommu_group *group;
1462 };
1463 
1464 /*
1465  * DMA alias iterator callback, return the last seen device.  Stop and return
1466  * the IOMMU group if we find one along the way.
1467  */
get_pci_alias_or_group(struct pci_dev * pdev,u16 alias,void * opaque)1468 static int get_pci_alias_or_group(struct pci_dev *pdev, u16 alias, void *opaque)
1469 {
1470 	struct group_for_pci_data *data = opaque;
1471 
1472 	data->pdev = pdev;
1473 	data->group = iommu_group_get(&pdev->dev);
1474 
1475 	return data->group != NULL;
1476 }
1477 
1478 /*
1479  * Generic device_group call-back function. It just allocates one
1480  * iommu-group per device.
1481  */
generic_device_group(struct device * dev)1482 struct iommu_group *generic_device_group(struct device *dev)
1483 {
1484 	return iommu_group_alloc();
1485 }
1486 EXPORT_SYMBOL_GPL(generic_device_group);
1487 
1488 /*
1489  * Generic device_group call-back function. It just allocates one
1490  * iommu-group per iommu driver instance shared by every device
1491  * probed by that iommu driver.
1492  */
generic_single_device_group(struct device * dev)1493 struct iommu_group *generic_single_device_group(struct device *dev)
1494 {
1495 	struct iommu_device *iommu = dev->iommu->iommu_dev;
1496 
1497 	if (!iommu->singleton_group) {
1498 		struct iommu_group *group;
1499 
1500 		group = iommu_group_alloc();
1501 		if (IS_ERR(group))
1502 			return group;
1503 		iommu->singleton_group = group;
1504 	}
1505 	return iommu_group_ref_get(iommu->singleton_group);
1506 }
1507 EXPORT_SYMBOL_GPL(generic_single_device_group);
1508 
1509 /*
1510  * Use standard PCI bus topology, isolation features, and DMA alias quirks
1511  * to find or create an IOMMU group for a device.
1512  */
pci_device_group(struct device * dev)1513 struct iommu_group *pci_device_group(struct device *dev)
1514 {
1515 	struct pci_dev *pdev = to_pci_dev(dev);
1516 	struct group_for_pci_data data;
1517 	struct pci_bus *bus;
1518 	struct iommu_group *group = NULL;
1519 	u64 devfns[4] = { 0 };
1520 
1521 	if (WARN_ON(!dev_is_pci(dev)))
1522 		return ERR_PTR(-EINVAL);
1523 
1524 	/*
1525 	 * Find the upstream DMA alias for the device.  A device must not
1526 	 * be aliased due to topology in order to have its own IOMMU group.
1527 	 * If we find an alias along the way that already belongs to a
1528 	 * group, use it.
1529 	 */
1530 	if (pci_for_each_dma_alias(pdev, get_pci_alias_or_group, &data))
1531 		return data.group;
1532 
1533 	pdev = data.pdev;
1534 
1535 	/*
1536 	 * Continue upstream from the point of minimum IOMMU granularity
1537 	 * due to aliases to the point where devices are protected from
1538 	 * peer-to-peer DMA by PCI ACS.  Again, if we find an existing
1539 	 * group, use it.
1540 	 */
1541 	for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
1542 		if (!bus->self)
1543 			continue;
1544 
1545 		if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS))
1546 			break;
1547 
1548 		pdev = bus->self;
1549 
1550 		group = iommu_group_get(&pdev->dev);
1551 		if (group)
1552 			return group;
1553 	}
1554 
1555 	/*
1556 	 * Look for existing groups on device aliases.  If we alias another
1557 	 * device or another device aliases us, use the same group.
1558 	 */
1559 	group = get_pci_alias_group(pdev, (unsigned long *)devfns);
1560 	if (group)
1561 		return group;
1562 
1563 	/*
1564 	 * Look for existing groups on non-isolated functions on the same
1565 	 * slot and aliases of those funcions, if any.  No need to clear
1566 	 * the search bitmap, the tested devfns are still valid.
1567 	 */
1568 	group = get_pci_function_alias_group(pdev, (unsigned long *)devfns);
1569 	if (group)
1570 		return group;
1571 
1572 	/* No shared group found, allocate new */
1573 	return iommu_group_alloc();
1574 }
1575 EXPORT_SYMBOL_GPL(pci_device_group);
1576 
1577 /* Get the IOMMU group for device on fsl-mc bus */
fsl_mc_device_group(struct device * dev)1578 struct iommu_group *fsl_mc_device_group(struct device *dev)
1579 {
1580 	struct device *cont_dev = fsl_mc_cont_dev(dev);
1581 	struct iommu_group *group;
1582 
1583 	group = iommu_group_get(cont_dev);
1584 	if (!group)
1585 		group = iommu_group_alloc();
1586 	return group;
1587 }
1588 EXPORT_SYMBOL_GPL(fsl_mc_device_group);
1589 
__iommu_alloc_identity_domain(struct device * dev)1590 static struct iommu_domain *__iommu_alloc_identity_domain(struct device *dev)
1591 {
1592 	const struct iommu_ops *ops = dev_iommu_ops(dev);
1593 	struct iommu_domain *domain;
1594 
1595 	if (ops->identity_domain)
1596 		return ops->identity_domain;
1597 
1598 	/* Older drivers create the identity domain via ops->domain_alloc() */
1599 	if (!ops->domain_alloc)
1600 		return ERR_PTR(-EOPNOTSUPP);
1601 
1602 	domain = ops->domain_alloc(IOMMU_DOMAIN_IDENTITY);
1603 	if (IS_ERR(domain))
1604 		return domain;
1605 	if (!domain)
1606 		return ERR_PTR(-ENOMEM);
1607 
1608 	iommu_domain_init(domain, IOMMU_DOMAIN_IDENTITY, ops);
1609 	return domain;
1610 }
1611 
1612 static struct iommu_domain *
__iommu_group_alloc_default_domain(struct iommu_group * group,int req_type)1613 __iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
1614 {
1615 	struct device *dev = iommu_group_first_dev(group);
1616 	struct iommu_domain *dom;
1617 
1618 	if (group->default_domain && group->default_domain->type == req_type)
1619 		return group->default_domain;
1620 
1621 	/*
1622 	 * When allocating the DMA API domain assume that the driver is going to
1623 	 * use PASID and make sure the RID's domain is PASID compatible.
1624 	 */
1625 	if (req_type & __IOMMU_DOMAIN_PAGING) {
1626 		dom = __iommu_paging_domain_alloc_flags(dev, req_type,
1627 			   dev->iommu->max_pasids ? IOMMU_HWPT_ALLOC_PASID : 0);
1628 
1629 		/*
1630 		 * If driver does not support PASID feature then
1631 		 * try to allocate non-PASID domain
1632 		 */
1633 		if (PTR_ERR(dom) == -EOPNOTSUPP)
1634 			dom = __iommu_paging_domain_alloc_flags(dev, req_type, 0);
1635 
1636 		return dom;
1637 	}
1638 
1639 	if (req_type == IOMMU_DOMAIN_IDENTITY)
1640 		return __iommu_alloc_identity_domain(dev);
1641 
1642 	return ERR_PTR(-EINVAL);
1643 }
1644 
1645 /*
1646  * req_type of 0 means "auto" which means to select a domain based on
1647  * iommu_def_domain_type or what the driver actually supports.
1648  */
1649 static struct iommu_domain *
iommu_group_alloc_default_domain(struct iommu_group * group,int req_type)1650 iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
1651 {
1652 	const struct iommu_ops *ops = dev_iommu_ops(iommu_group_first_dev(group));
1653 	struct iommu_domain *dom;
1654 
1655 	lockdep_assert_held(&group->mutex);
1656 
1657 	/*
1658 	 * Allow legacy drivers to specify the domain that will be the default
1659 	 * domain. This should always be either an IDENTITY/BLOCKED/PLATFORM
1660 	 * domain. Do not use in new drivers.
1661 	 */
1662 	if (ops->default_domain) {
1663 		if (req_type != ops->default_domain->type)
1664 			return ERR_PTR(-EINVAL);
1665 		return ops->default_domain;
1666 	}
1667 
1668 	if (req_type)
1669 		return __iommu_group_alloc_default_domain(group, req_type);
1670 
1671 	/* The driver gave no guidance on what type to use, try the default */
1672 	dom = __iommu_group_alloc_default_domain(group, iommu_def_domain_type);
1673 	if (!IS_ERR(dom))
1674 		return dom;
1675 
1676 	/* Otherwise IDENTITY and DMA_FQ defaults will try DMA */
1677 	if (iommu_def_domain_type == IOMMU_DOMAIN_DMA)
1678 		return ERR_PTR(-EINVAL);
1679 	dom = __iommu_group_alloc_default_domain(group, IOMMU_DOMAIN_DMA);
1680 	if (IS_ERR(dom))
1681 		return dom;
1682 
1683 	pr_warn("Failed to allocate default IOMMU domain of type %u for group %s - Falling back to IOMMU_DOMAIN_DMA",
1684 		iommu_def_domain_type, group->name);
1685 	return dom;
1686 }
1687 
iommu_group_default_domain(struct iommu_group * group)1688 struct iommu_domain *iommu_group_default_domain(struct iommu_group *group)
1689 {
1690 	return group->default_domain;
1691 }
1692 
probe_iommu_group(struct device * dev,void * data)1693 static int probe_iommu_group(struct device *dev, void *data)
1694 {
1695 	struct list_head *group_list = data;
1696 	int ret;
1697 
1698 	mutex_lock(&iommu_probe_device_lock);
1699 	ret = __iommu_probe_device(dev, group_list);
1700 	mutex_unlock(&iommu_probe_device_lock);
1701 	if (ret == -ENODEV)
1702 		ret = 0;
1703 
1704 	return ret;
1705 }
1706 
iommu_bus_notifier(struct notifier_block * nb,unsigned long action,void * data)1707 static int iommu_bus_notifier(struct notifier_block *nb,
1708 			      unsigned long action, void *data)
1709 {
1710 	struct device *dev = data;
1711 
1712 	if (action == BUS_NOTIFY_ADD_DEVICE) {
1713 		int ret;
1714 
1715 		ret = iommu_probe_device(dev);
1716 		return (ret) ? NOTIFY_DONE : NOTIFY_OK;
1717 	} else if (action == BUS_NOTIFY_REMOVED_DEVICE) {
1718 		iommu_release_device(dev);
1719 		return NOTIFY_OK;
1720 	}
1721 
1722 	return 0;
1723 }
1724 
1725 /*
1726  * Combine the driver's chosen def_domain_type across all the devices in a
1727  * group. Drivers must give a consistent result.
1728  */
iommu_get_def_domain_type(struct iommu_group * group,struct device * dev,int cur_type)1729 static int iommu_get_def_domain_type(struct iommu_group *group,
1730 				     struct device *dev, int cur_type)
1731 {
1732 	const struct iommu_ops *ops = dev_iommu_ops(dev);
1733 	int type;
1734 
1735 	if (ops->default_domain) {
1736 		/*
1737 		 * Drivers that declare a global static default_domain will
1738 		 * always choose that.
1739 		 */
1740 		type = ops->default_domain->type;
1741 	} else {
1742 		if (ops->def_domain_type)
1743 			type = ops->def_domain_type(dev);
1744 		else
1745 			return cur_type;
1746 	}
1747 	if (!type || cur_type == type)
1748 		return cur_type;
1749 	if (!cur_type)
1750 		return type;
1751 
1752 	dev_err_ratelimited(
1753 		dev,
1754 		"IOMMU driver error, requesting conflicting def_domain_type, %s and %s, for devices in group %u.\n",
1755 		iommu_domain_type_str(cur_type), iommu_domain_type_str(type),
1756 		group->id);
1757 
1758 	/*
1759 	 * Try to recover, drivers are allowed to force IDENITY or DMA, IDENTITY
1760 	 * takes precedence.
1761 	 */
1762 	if (type == IOMMU_DOMAIN_IDENTITY)
1763 		return type;
1764 	return cur_type;
1765 }
1766 
1767 /*
1768  * A target_type of 0 will select the best domain type. 0 can be returned in
1769  * this case meaning the global default should be used.
1770  */
iommu_get_default_domain_type(struct iommu_group * group,int target_type)1771 static int iommu_get_default_domain_type(struct iommu_group *group,
1772 					 int target_type)
1773 {
1774 	struct device *untrusted = NULL;
1775 	struct group_device *gdev;
1776 	int driver_type = 0;
1777 
1778 	lockdep_assert_held(&group->mutex);
1779 
1780 	/*
1781 	 * ARM32 drivers supporting CONFIG_ARM_DMA_USE_IOMMU can declare an
1782 	 * identity_domain and it will automatically become their default
1783 	 * domain. Later on ARM_DMA_USE_IOMMU will install its UNMANAGED domain.
1784 	 * Override the selection to IDENTITY.
1785 	 */
1786 	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
1787 		static_assert(!(IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU) &&
1788 				IS_ENABLED(CONFIG_IOMMU_DMA)));
1789 		driver_type = IOMMU_DOMAIN_IDENTITY;
1790 	}
1791 
1792 	for_each_group_device(group, gdev) {
1793 		driver_type = iommu_get_def_domain_type(group, gdev->dev,
1794 							driver_type);
1795 
1796 		if (dev_is_pci(gdev->dev) && to_pci_dev(gdev->dev)->untrusted) {
1797 			/*
1798 			 * No ARM32 using systems will set untrusted, it cannot
1799 			 * work.
1800 			 */
1801 			if (WARN_ON(IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)))
1802 				return -1;
1803 			untrusted = gdev->dev;
1804 		}
1805 	}
1806 
1807 	/*
1808 	 * If the common dma ops are not selected in kconfig then we cannot use
1809 	 * IOMMU_DOMAIN_DMA at all. Force IDENTITY if nothing else has been
1810 	 * selected.
1811 	 */
1812 	if (!IS_ENABLED(CONFIG_IOMMU_DMA)) {
1813 		if (WARN_ON(driver_type == IOMMU_DOMAIN_DMA))
1814 			return -1;
1815 		if (!driver_type)
1816 			driver_type = IOMMU_DOMAIN_IDENTITY;
1817 	}
1818 
1819 	if (untrusted) {
1820 		if (driver_type && driver_type != IOMMU_DOMAIN_DMA) {
1821 			dev_err_ratelimited(
1822 				untrusted,
1823 				"Device is not trusted, but driver is overriding group %u to %s, refusing to probe.\n",
1824 				group->id, iommu_domain_type_str(driver_type));
1825 			return -1;
1826 		}
1827 		driver_type = IOMMU_DOMAIN_DMA;
1828 	}
1829 
1830 	if (target_type) {
1831 		if (driver_type && target_type != driver_type)
1832 			return -1;
1833 		return target_type;
1834 	}
1835 	return driver_type;
1836 }
1837 
iommu_group_do_probe_finalize(struct device * dev)1838 static void iommu_group_do_probe_finalize(struct device *dev)
1839 {
1840 	const struct iommu_ops *ops = dev_iommu_ops(dev);
1841 
1842 	if (ops->probe_finalize)
1843 		ops->probe_finalize(dev);
1844 }
1845 
bus_iommu_probe(const struct bus_type * bus)1846 static int bus_iommu_probe(const struct bus_type *bus)
1847 {
1848 	struct iommu_group *group, *next;
1849 	LIST_HEAD(group_list);
1850 	int ret;
1851 
1852 	ret = bus_for_each_dev(bus, NULL, &group_list, probe_iommu_group);
1853 	if (ret)
1854 		return ret;
1855 
1856 	list_for_each_entry_safe(group, next, &group_list, entry) {
1857 		struct group_device *gdev;
1858 
1859 		mutex_lock(&group->mutex);
1860 
1861 		/* Remove item from the list */
1862 		list_del_init(&group->entry);
1863 
1864 		/*
1865 		 * We go to the trouble of deferred default domain creation so
1866 		 * that the cross-group default domain type and the setup of the
1867 		 * IOMMU_RESV_DIRECT will work correctly in non-hotpug scenarios.
1868 		 */
1869 		ret = iommu_setup_default_domain(group, 0);
1870 		if (ret) {
1871 			mutex_unlock(&group->mutex);
1872 			return ret;
1873 		}
1874 		for_each_group_device(group, gdev)
1875 			iommu_setup_dma_ops(gdev->dev);
1876 		mutex_unlock(&group->mutex);
1877 
1878 		/*
1879 		 * FIXME: Mis-locked because the ops->probe_finalize() call-back
1880 		 * of some IOMMU drivers calls arm_iommu_attach_device() which
1881 		 * in-turn might call back into IOMMU core code, where it tries
1882 		 * to take group->mutex, resulting in a deadlock.
1883 		 */
1884 		for_each_group_device(group, gdev)
1885 			iommu_group_do_probe_finalize(gdev->dev);
1886 	}
1887 
1888 	return 0;
1889 }
1890 
1891 /**
1892  * device_iommu_capable() - check for a general IOMMU capability
1893  * @dev: device to which the capability would be relevant, if available
1894  * @cap: IOMMU capability
1895  *
1896  * Return: true if an IOMMU is present and supports the given capability
1897  * for the given device, otherwise false.
1898  */
device_iommu_capable(struct device * dev,enum iommu_cap cap)1899 bool device_iommu_capable(struct device *dev, enum iommu_cap cap)
1900 {
1901 	const struct iommu_ops *ops;
1902 
1903 	if (!dev_has_iommu(dev))
1904 		return false;
1905 
1906 	ops = dev_iommu_ops(dev);
1907 	if (!ops->capable)
1908 		return false;
1909 
1910 	return ops->capable(dev, cap);
1911 }
1912 EXPORT_SYMBOL_GPL(device_iommu_capable);
1913 
1914 /**
1915  * iommu_group_has_isolated_msi() - Compute msi_device_has_isolated_msi()
1916  *       for a group
1917  * @group: Group to query
1918  *
1919  * IOMMU groups should not have differing values of
1920  * msi_device_has_isolated_msi() for devices in a group. However nothing
1921  * directly prevents this, so ensure mistakes don't result in isolation failures
1922  * by checking that all the devices are the same.
1923  */
iommu_group_has_isolated_msi(struct iommu_group * group)1924 bool iommu_group_has_isolated_msi(struct iommu_group *group)
1925 {
1926 	struct group_device *group_dev;
1927 	bool ret = true;
1928 
1929 	mutex_lock(&group->mutex);
1930 	for_each_group_device(group, group_dev)
1931 		ret &= msi_device_has_isolated_msi(group_dev->dev);
1932 	mutex_unlock(&group->mutex);
1933 	return ret;
1934 }
1935 EXPORT_SYMBOL_GPL(iommu_group_has_isolated_msi);
1936 
1937 /**
1938  * iommu_set_fault_handler() - set a fault handler for an iommu domain
1939  * @domain: iommu domain
1940  * @handler: fault handler
1941  * @token: user data, will be passed back to the fault handler
1942  *
1943  * This function should be used by IOMMU users which want to be notified
1944  * whenever an IOMMU fault happens.
1945  *
1946  * The fault handler itself should return 0 on success, and an appropriate
1947  * error code otherwise.
1948  */
iommu_set_fault_handler(struct iommu_domain * domain,iommu_fault_handler_t handler,void * token)1949 void iommu_set_fault_handler(struct iommu_domain *domain,
1950 					iommu_fault_handler_t handler,
1951 					void *token)
1952 {
1953 	BUG_ON(!domain);
1954 
1955 	domain->handler = handler;
1956 	domain->handler_token = token;
1957 }
1958 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
1959 
iommu_domain_init(struct iommu_domain * domain,unsigned int type,const struct iommu_ops * ops)1960 static void iommu_domain_init(struct iommu_domain *domain, unsigned int type,
1961 			      const struct iommu_ops *ops)
1962 {
1963 	domain->type = type;
1964 	domain->owner = ops;
1965 	if (!domain->ops)
1966 		domain->ops = ops->default_domain_ops;
1967 
1968 	/*
1969 	 * If not already set, assume all sizes by default; the driver
1970 	 * may override this later
1971 	 */
1972 	if (!domain->pgsize_bitmap)
1973 		domain->pgsize_bitmap = ops->pgsize_bitmap;
1974 }
1975 
1976 static struct iommu_domain *
__iommu_paging_domain_alloc_flags(struct device * dev,unsigned int type,unsigned int flags)1977 __iommu_paging_domain_alloc_flags(struct device *dev, unsigned int type,
1978 				  unsigned int flags)
1979 {
1980 	const struct iommu_ops *ops;
1981 	struct iommu_domain *domain;
1982 
1983 	if (!dev_has_iommu(dev))
1984 		return ERR_PTR(-ENODEV);
1985 
1986 	ops = dev_iommu_ops(dev);
1987 
1988 	if (ops->domain_alloc_paging && !flags)
1989 		domain = ops->domain_alloc_paging(dev);
1990 	else if (ops->domain_alloc_paging_flags)
1991 		domain = ops->domain_alloc_paging_flags(dev, flags, NULL);
1992 	else if (ops->domain_alloc && !flags)
1993 		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);
1994 	else
1995 		return ERR_PTR(-EOPNOTSUPP);
1996 
1997 	if (IS_ERR(domain))
1998 		return domain;
1999 	if (!domain)
2000 		return ERR_PTR(-ENOMEM);
2001 
2002 	iommu_domain_init(domain, type, ops);
2003 	return domain;
2004 }
2005 
2006 /**
2007  * iommu_paging_domain_alloc_flags() - Allocate a paging domain
2008  * @dev: device for which the domain is allocated
2009  * @flags: Bitmap of iommufd_hwpt_alloc_flags
2010  *
2011  * Allocate a paging domain which will be managed by a kernel driver. Return
2012  * allocated domain if successful, or an ERR pointer for failure.
2013  */
iommu_paging_domain_alloc_flags(struct device * dev,unsigned int flags)2014 struct iommu_domain *iommu_paging_domain_alloc_flags(struct device *dev,
2015 						     unsigned int flags)
2016 {
2017 	return __iommu_paging_domain_alloc_flags(dev,
2018 					 IOMMU_DOMAIN_UNMANAGED, flags);
2019 }
2020 EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc_flags);
2021 
iommu_domain_free(struct iommu_domain * domain)2022 void iommu_domain_free(struct iommu_domain *domain)
2023 {
2024 	if (domain->type == IOMMU_DOMAIN_SVA)
2025 		mmdrop(domain->mm);
2026 	iommu_put_dma_cookie(domain);
2027 	if (domain->ops->free)
2028 		domain->ops->free(domain);
2029 }
2030 EXPORT_SYMBOL_GPL(iommu_domain_free);
2031 
2032 /*
2033  * Put the group's domain back to the appropriate core-owned domain - either the
2034  * standard kernel-mode DMA configuration or an all-DMA-blocked domain.
2035  */
__iommu_group_set_core_domain(struct iommu_group * group)2036 static void __iommu_group_set_core_domain(struct iommu_group *group)
2037 {
2038 	struct iommu_domain *new_domain;
2039 
2040 	if (group->owner)
2041 		new_domain = group->blocking_domain;
2042 	else
2043 		new_domain = group->default_domain;
2044 
2045 	__iommu_group_set_domain_nofail(group, new_domain);
2046 }
2047 
__iommu_attach_device(struct iommu_domain * domain,struct device * dev)2048 static int __iommu_attach_device(struct iommu_domain *domain,
2049 				 struct device *dev)
2050 {
2051 	int ret;
2052 
2053 	if (unlikely(domain->ops->attach_dev == NULL))
2054 		return -ENODEV;
2055 
2056 	ret = domain->ops->attach_dev(domain, dev);
2057 	if (ret)
2058 		return ret;
2059 	dev->iommu->attach_deferred = 0;
2060 	trace_attach_device_to_domain(dev);
2061 	return 0;
2062 }
2063 
2064 /**
2065  * iommu_attach_device - Attach an IOMMU domain to a device
2066  * @domain: IOMMU domain to attach
2067  * @dev: Device that will be attached
2068  *
2069  * Returns 0 on success and error code on failure
2070  *
2071  * Note that EINVAL can be treated as a soft failure, indicating
2072  * that certain configuration of the domain is incompatible with
2073  * the device. In this case attaching a different domain to the
2074  * device may succeed.
2075  */
iommu_attach_device(struct iommu_domain * domain,struct device * dev)2076 int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
2077 {
2078 	/* Caller must be a probed driver on dev */
2079 	struct iommu_group *group = dev->iommu_group;
2080 	int ret;
2081 
2082 	if (!group)
2083 		return -ENODEV;
2084 
2085 	/*
2086 	 * Lock the group to make sure the device-count doesn't
2087 	 * change while we are attaching
2088 	 */
2089 	mutex_lock(&group->mutex);
2090 	ret = -EINVAL;
2091 	if (list_count_nodes(&group->devices) != 1)
2092 		goto out_unlock;
2093 
2094 	ret = __iommu_attach_group(domain, group);
2095 
2096 out_unlock:
2097 	mutex_unlock(&group->mutex);
2098 	return ret;
2099 }
2100 EXPORT_SYMBOL_GPL(iommu_attach_device);
2101 
iommu_deferred_attach(struct device * dev,struct iommu_domain * domain)2102 int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain)
2103 {
2104 	if (dev->iommu && dev->iommu->attach_deferred)
2105 		return __iommu_attach_device(domain, dev);
2106 
2107 	return 0;
2108 }
2109 
iommu_detach_device(struct iommu_domain * domain,struct device * dev)2110 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
2111 {
2112 	/* Caller must be a probed driver on dev */
2113 	struct iommu_group *group = dev->iommu_group;
2114 
2115 	if (!group)
2116 		return;
2117 
2118 	mutex_lock(&group->mutex);
2119 	if (WARN_ON(domain != group->domain) ||
2120 	    WARN_ON(list_count_nodes(&group->devices) != 1))
2121 		goto out_unlock;
2122 	__iommu_group_set_core_domain(group);
2123 
2124 out_unlock:
2125 	mutex_unlock(&group->mutex);
2126 }
2127 EXPORT_SYMBOL_GPL(iommu_detach_device);
2128 
iommu_get_domain_for_dev(struct device * dev)2129 struct iommu_domain *iommu_get_domain_for_dev(struct device *dev)
2130 {
2131 	/* Caller must be a probed driver on dev */
2132 	struct iommu_group *group = dev->iommu_group;
2133 
2134 	if (!group)
2135 		return NULL;
2136 
2137 	return group->domain;
2138 }
2139 EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev);
2140 
2141 /*
2142  * For IOMMU_DOMAIN_DMA implementations which already provide their own
2143  * guarantees that the group and its default domain are valid and correct.
2144  */
iommu_get_dma_domain(struct device * dev)2145 struct iommu_domain *iommu_get_dma_domain(struct device *dev)
2146 {
2147 	return dev->iommu_group->default_domain;
2148 }
2149 
__iommu_attach_group(struct iommu_domain * domain,struct iommu_group * group)2150 static int __iommu_attach_group(struct iommu_domain *domain,
2151 				struct iommu_group *group)
2152 {
2153 	struct device *dev;
2154 
2155 	if (group->domain && group->domain != group->default_domain &&
2156 	    group->domain != group->blocking_domain)
2157 		return -EBUSY;
2158 
2159 	dev = iommu_group_first_dev(group);
2160 	if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner)
2161 		return -EINVAL;
2162 
2163 	return __iommu_group_set_domain(group, domain);
2164 }
2165 
2166 /**
2167  * iommu_attach_group - Attach an IOMMU domain to an IOMMU group
2168  * @domain: IOMMU domain to attach
2169  * @group: IOMMU group that will be attached
2170  *
2171  * Returns 0 on success and error code on failure
2172  *
2173  * Note that EINVAL can be treated as a soft failure, indicating
2174  * that certain configuration of the domain is incompatible with
2175  * the group. In this case attaching a different domain to the
2176  * group may succeed.
2177  */
iommu_attach_group(struct iommu_domain * domain,struct iommu_group * group)2178 int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
2179 {
2180 	int ret;
2181 
2182 	mutex_lock(&group->mutex);
2183 	ret = __iommu_attach_group(domain, group);
2184 	mutex_unlock(&group->mutex);
2185 
2186 	return ret;
2187 }
2188 EXPORT_SYMBOL_GPL(iommu_attach_group);
2189 
2190 /**
2191  * iommu_group_replace_domain - replace the domain that a group is attached to
2192  * @group: IOMMU group that will be attached to the new domain
2193  * @new_domain: new IOMMU domain to replace with
2194  *
2195  * This API allows the group to switch domains without being forced to go to
2196  * the blocking domain in-between.
2197  *
2198  * If the currently attached domain is a core domain (e.g. a default_domain),
2199  * it will act just like the iommu_attach_group().
2200  */
iommu_group_replace_domain(struct iommu_group * group,struct iommu_domain * new_domain)2201 int iommu_group_replace_domain(struct iommu_group *group,
2202 			       struct iommu_domain *new_domain)
2203 {
2204 	int ret;
2205 
2206 	if (!new_domain)
2207 		return -EINVAL;
2208 
2209 	mutex_lock(&group->mutex);
2210 	ret = __iommu_group_set_domain(group, new_domain);
2211 	mutex_unlock(&group->mutex);
2212 	return ret;
2213 }
2214 EXPORT_SYMBOL_NS_GPL(iommu_group_replace_domain, "IOMMUFD_INTERNAL");
2215 
__iommu_device_set_domain(struct iommu_group * group,struct device * dev,struct iommu_domain * new_domain,unsigned int flags)2216 static int __iommu_device_set_domain(struct iommu_group *group,
2217 				     struct device *dev,
2218 				     struct iommu_domain *new_domain,
2219 				     unsigned int flags)
2220 {
2221 	int ret;
2222 
2223 	/*
2224 	 * If the device requires IOMMU_RESV_DIRECT then we cannot allow
2225 	 * the blocking domain to be attached as it does not contain the
2226 	 * required 1:1 mapping. This test effectively excludes the device
2227 	 * being used with iommu_group_claim_dma_owner() which will block
2228 	 * vfio and iommufd as well.
2229 	 */
2230 	if (dev->iommu->require_direct &&
2231 	    (new_domain->type == IOMMU_DOMAIN_BLOCKED ||
2232 	     new_domain == group->blocking_domain)) {
2233 		dev_warn(dev,
2234 			 "Firmware has requested this device have a 1:1 IOMMU mapping, rejecting configuring the device without a 1:1 mapping. Contact your platform vendor.\n");
2235 		return -EINVAL;
2236 	}
2237 
2238 	if (dev->iommu->attach_deferred) {
2239 		if (new_domain == group->default_domain)
2240 			return 0;
2241 		dev->iommu->attach_deferred = 0;
2242 	}
2243 
2244 	ret = __iommu_attach_device(new_domain, dev);
2245 	if (ret) {
2246 		/*
2247 		 * If we have a blocking domain then try to attach that in hopes
2248 		 * of avoiding a UAF. Modern drivers should implement blocking
2249 		 * domains as global statics that cannot fail.
2250 		 */
2251 		if ((flags & IOMMU_SET_DOMAIN_MUST_SUCCEED) &&
2252 		    group->blocking_domain &&
2253 		    group->blocking_domain != new_domain)
2254 			__iommu_attach_device(group->blocking_domain, dev);
2255 		return ret;
2256 	}
2257 	return 0;
2258 }
2259 
2260 /*
2261  * If 0 is returned the group's domain is new_domain. If an error is returned
2262  * then the group's domain will be set back to the existing domain unless
2263  * IOMMU_SET_DOMAIN_MUST_SUCCEED, otherwise an error is returned and the group's
2264  * domains is left inconsistent. This is a driver bug to fail attach with a
2265  * previously good domain. We try to avoid a kernel UAF because of this.
2266  *
2267  * IOMMU groups are really the natural working unit of the IOMMU, but the IOMMU
2268  * API works on domains and devices.  Bridge that gap by iterating over the
2269  * devices in a group.  Ideally we'd have a single device which represents the
2270  * requestor ID of the group, but we also allow IOMMU drivers to create policy
2271  * defined minimum sets, where the physical hardware may be able to distiguish
2272  * members, but we wish to group them at a higher level (ex. untrusted
2273  * multi-function PCI devices).  Thus we attach each device.
2274  */
__iommu_group_set_domain_internal(struct iommu_group * group,struct iommu_domain * new_domain,unsigned int flags)2275 static int __iommu_group_set_domain_internal(struct iommu_group *group,
2276 					     struct iommu_domain *new_domain,
2277 					     unsigned int flags)
2278 {
2279 	struct group_device *last_gdev;
2280 	struct group_device *gdev;
2281 	int result;
2282 	int ret;
2283 
2284 	lockdep_assert_held(&group->mutex);
2285 
2286 	if (group->domain == new_domain)
2287 		return 0;
2288 
2289 	if (WARN_ON(!new_domain))
2290 		return -EINVAL;
2291 
2292 	/*
2293 	 * Changing the domain is done by calling attach_dev() on the new
2294 	 * domain. This switch does not have to be atomic and DMA can be
2295 	 * discarded during the transition. DMA must only be able to access
2296 	 * either new_domain or group->domain, never something else.
2297 	 */
2298 	result = 0;
2299 	for_each_group_device(group, gdev) {
2300 		ret = __iommu_device_set_domain(group, gdev->dev, new_domain,
2301 						flags);
2302 		if (ret) {
2303 			result = ret;
2304 			/*
2305 			 * Keep trying the other devices in the group. If a
2306 			 * driver fails attach to an otherwise good domain, and
2307 			 * does not support blocking domains, it should at least
2308 			 * drop its reference on the current domain so we don't
2309 			 * UAF.
2310 			 */
2311 			if (flags & IOMMU_SET_DOMAIN_MUST_SUCCEED)
2312 				continue;
2313 			goto err_revert;
2314 		}
2315 	}
2316 	group->domain = new_domain;
2317 	return result;
2318 
2319 err_revert:
2320 	/*
2321 	 * This is called in error unwind paths. A well behaved driver should
2322 	 * always allow us to attach to a domain that was already attached.
2323 	 */
2324 	last_gdev = gdev;
2325 	for_each_group_device(group, gdev) {
2326 		/*
2327 		 * A NULL domain can happen only for first probe, in which case
2328 		 * we leave group->domain as NULL and let release clean
2329 		 * everything up.
2330 		 */
2331 		if (group->domain)
2332 			WARN_ON(__iommu_device_set_domain(
2333 				group, gdev->dev, group->domain,
2334 				IOMMU_SET_DOMAIN_MUST_SUCCEED));
2335 		if (gdev == last_gdev)
2336 			break;
2337 	}
2338 	return ret;
2339 }
2340 
iommu_detach_group(struct iommu_domain * domain,struct iommu_group * group)2341 void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group)
2342 {
2343 	mutex_lock(&group->mutex);
2344 	__iommu_group_set_core_domain(group);
2345 	mutex_unlock(&group->mutex);
2346 }
2347 EXPORT_SYMBOL_GPL(iommu_detach_group);
2348 
iommu_iova_to_phys(struct iommu_domain * domain,dma_addr_t iova)2349 phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)
2350 {
2351 	if (domain->type == IOMMU_DOMAIN_IDENTITY)
2352 		return iova;
2353 
2354 	if (domain->type == IOMMU_DOMAIN_BLOCKED)
2355 		return 0;
2356 
2357 	return domain->ops->iova_to_phys(domain, iova);
2358 }
2359 EXPORT_SYMBOL_GPL(iommu_iova_to_phys);
2360 
iommu_pgsize(struct iommu_domain * domain,unsigned long iova,phys_addr_t paddr,size_t size,size_t * count)2361 static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova,
2362 			   phys_addr_t paddr, size_t size, size_t *count)
2363 {
2364 	unsigned int pgsize_idx, pgsize_idx_next;
2365 	unsigned long pgsizes;
2366 	size_t offset, pgsize, pgsize_next;
2367 	unsigned long addr_merge = paddr | iova;
2368 
2369 	/* Page sizes supported by the hardware and small enough for @size */
2370 	pgsizes = domain->pgsize_bitmap & GENMASK(__fls(size), 0);
2371 
2372 	/* Constrain the page sizes further based on the maximum alignment */
2373 	if (likely(addr_merge))
2374 		pgsizes &= GENMASK(__ffs(addr_merge), 0);
2375 
2376 	/* Make sure we have at least one suitable page size */
2377 	BUG_ON(!pgsizes);
2378 
2379 	/* Pick the biggest page size remaining */
2380 	pgsize_idx = __fls(pgsizes);
2381 	pgsize = BIT(pgsize_idx);
2382 	if (!count)
2383 		return pgsize;
2384 
2385 	/* Find the next biggest support page size, if it exists */
2386 	pgsizes = domain->pgsize_bitmap & ~GENMASK(pgsize_idx, 0);
2387 	if (!pgsizes)
2388 		goto out_set_count;
2389 
2390 	pgsize_idx_next = __ffs(pgsizes);
2391 	pgsize_next = BIT(pgsize_idx_next);
2392 
2393 	/*
2394 	 * There's no point trying a bigger page size unless the virtual
2395 	 * and physical addresses are similarly offset within the larger page.
2396 	 */
2397 	if ((iova ^ paddr) & (pgsize_next - 1))
2398 		goto out_set_count;
2399 
2400 	/* Calculate the offset to the next page size alignment boundary */
2401 	offset = pgsize_next - (addr_merge & (pgsize_next - 1));
2402 
2403 	/*
2404 	 * If size is big enough to accommodate the larger page, reduce
2405 	 * the number of smaller pages.
2406 	 */
2407 	if (offset + pgsize_next <= size)
2408 		size = offset;
2409 
2410 out_set_count:
2411 	*count = size >> pgsize_idx;
2412 	return pgsize;
2413 }
2414 
__iommu_map(struct iommu_domain * domain,unsigned long iova,phys_addr_t paddr,size_t size,int prot,gfp_t gfp)2415 static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
2416 		       phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
2417 {
2418 	const struct iommu_domain_ops *ops = domain->ops;
2419 	unsigned long orig_iova = iova;
2420 	unsigned int min_pagesz;
2421 	size_t orig_size = size;
2422 	phys_addr_t orig_paddr = paddr;
2423 	int ret = 0;
2424 
2425 	if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
2426 		return -EINVAL;
2427 
2428 	if (WARN_ON(!ops->map_pages || domain->pgsize_bitmap == 0UL))
2429 		return -ENODEV;
2430 
2431 	/* find out the minimum page size supported */
2432 	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
2433 
2434 	/*
2435 	 * both the virtual address and the physical one, as well as
2436 	 * the size of the mapping, must be aligned (at least) to the
2437 	 * size of the smallest page supported by the hardware
2438 	 */
2439 	if (!IS_ALIGNED(iova | paddr | size, min_pagesz)) {
2440 		pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%x\n",
2441 		       iova, &paddr, size, min_pagesz);
2442 		return -EINVAL;
2443 	}
2444 
2445 	pr_debug("map: iova 0x%lx pa %pa size 0x%zx\n", iova, &paddr, size);
2446 
2447 	while (size) {
2448 		size_t pgsize, count, mapped = 0;
2449 
2450 		pgsize = iommu_pgsize(domain, iova, paddr, size, &count);
2451 
2452 		pr_debug("mapping: iova 0x%lx pa %pa pgsize 0x%zx count %zu\n",
2453 			 iova, &paddr, pgsize, count);
2454 		ret = ops->map_pages(domain, iova, paddr, pgsize, count, prot,
2455 				     gfp, &mapped);
2456 		/*
2457 		 * Some pages may have been mapped, even if an error occurred,
2458 		 * so we should account for those so they can be unmapped.
2459 		 */
2460 		size -= mapped;
2461 
2462 		if (ret)
2463 			break;
2464 
2465 		iova += mapped;
2466 		paddr += mapped;
2467 	}
2468 
2469 	/* unroll mapping in case something went wrong */
2470 	if (ret)
2471 		iommu_unmap(domain, orig_iova, orig_size - size);
2472 	else
2473 		trace_map(orig_iova, orig_paddr, orig_size);
2474 
2475 	return ret;
2476 }
2477 
iommu_map(struct iommu_domain * domain,unsigned long iova,phys_addr_t paddr,size_t size,int prot,gfp_t gfp)2478 int iommu_map(struct iommu_domain *domain, unsigned long iova,
2479 	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
2480 {
2481 	const struct iommu_domain_ops *ops = domain->ops;
2482 	int ret;
2483 
2484 	might_sleep_if(gfpflags_allow_blocking(gfp));
2485 
2486 	/* Discourage passing strange GFP flags */
2487 	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
2488 				__GFP_HIGHMEM)))
2489 		return -EINVAL;
2490 
2491 	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
2492 	if (ret == 0 && ops->iotlb_sync_map) {
2493 		ret = ops->iotlb_sync_map(domain, iova, size);
2494 		if (ret)
2495 			goto out_err;
2496 	}
2497 
2498 	return ret;
2499 
2500 out_err:
2501 	/* undo mappings already done */
2502 	iommu_unmap(domain, iova, size);
2503 
2504 	return ret;
2505 }
2506 EXPORT_SYMBOL_GPL(iommu_map);
2507 
__iommu_unmap(struct iommu_domain * domain,unsigned long iova,size_t size,struct iommu_iotlb_gather * iotlb_gather)2508 static size_t __iommu_unmap(struct iommu_domain *domain,
2509 			    unsigned long iova, size_t size,
2510 			    struct iommu_iotlb_gather *iotlb_gather)
2511 {
2512 	const struct iommu_domain_ops *ops = domain->ops;
2513 	size_t unmapped_page, unmapped = 0;
2514 	unsigned long orig_iova = iova;
2515 	unsigned int min_pagesz;
2516 
2517 	if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
2518 		return 0;
2519 
2520 	if (WARN_ON(!ops->unmap_pages || domain->pgsize_bitmap == 0UL))
2521 		return 0;
2522 
2523 	/* find out the minimum page size supported */
2524 	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
2525 
2526 	/*
2527 	 * The virtual address, as well as the size of the mapping, must be
2528 	 * aligned (at least) to the size of the smallest page supported
2529 	 * by the hardware
2530 	 */
2531 	if (!IS_ALIGNED(iova | size, min_pagesz)) {
2532 		pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n",
2533 		       iova, size, min_pagesz);
2534 		return 0;
2535 	}
2536 
2537 	pr_debug("unmap this: iova 0x%lx size 0x%zx\n", iova, size);
2538 
2539 	/*
2540 	 * Keep iterating until we either unmap 'size' bytes (or more)
2541 	 * or we hit an area that isn't mapped.
2542 	 */
2543 	while (unmapped < size) {
2544 		size_t pgsize, count;
2545 
2546 		pgsize = iommu_pgsize(domain, iova, iova, size - unmapped, &count);
2547 		unmapped_page = ops->unmap_pages(domain, iova, pgsize, count, iotlb_gather);
2548 		if (!unmapped_page)
2549 			break;
2550 
2551 		pr_debug("unmapped: iova 0x%lx size 0x%zx\n",
2552 			 iova, unmapped_page);
2553 
2554 		iova += unmapped_page;
2555 		unmapped += unmapped_page;
2556 	}
2557 
2558 	trace_unmap(orig_iova, size, unmapped);
2559 	return unmapped;
2560 }
2561 
2562 /**
2563  * iommu_unmap() - Remove mappings from a range of IOVA
2564  * @domain: Domain to manipulate
2565  * @iova: IO virtual address to start
2566  * @size: Length of the range starting from @iova
2567  *
2568  * iommu_unmap() will remove a translation created by iommu_map(). It cannot
2569  * subdivide a mapping created by iommu_map(), so it should be called with IOVA
2570  * ranges that match what was passed to iommu_map(). The range can aggregate
2571  * contiguous iommu_map() calls so long as no individual range is split.
2572  *
2573  * Returns: Number of bytes of IOVA unmapped. iova + res will be the point
2574  * unmapping stopped.
2575  */
iommu_unmap(struct iommu_domain * domain,unsigned long iova,size_t size)2576 size_t iommu_unmap(struct iommu_domain *domain,
2577 		   unsigned long iova, size_t size)
2578 {
2579 	struct iommu_iotlb_gather iotlb_gather;
2580 	size_t ret;
2581 
2582 	iommu_iotlb_gather_init(&iotlb_gather);
2583 	ret = __iommu_unmap(domain, iova, size, &iotlb_gather);
2584 	iommu_iotlb_sync(domain, &iotlb_gather);
2585 
2586 	return ret;
2587 }
2588 EXPORT_SYMBOL_GPL(iommu_unmap);
2589 
iommu_unmap_fast(struct iommu_domain * domain,unsigned long iova,size_t size,struct iommu_iotlb_gather * iotlb_gather)2590 size_t iommu_unmap_fast(struct iommu_domain *domain,
2591 			unsigned long iova, size_t size,
2592 			struct iommu_iotlb_gather *iotlb_gather)
2593 {
2594 	return __iommu_unmap(domain, iova, size, iotlb_gather);
2595 }
2596 EXPORT_SYMBOL_GPL(iommu_unmap_fast);
2597 
iommu_map_sg(struct iommu_domain * domain,unsigned long iova,struct scatterlist * sg,unsigned int nents,int prot,gfp_t gfp)2598 ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
2599 		     struct scatterlist *sg, unsigned int nents, int prot,
2600 		     gfp_t gfp)
2601 {
2602 	const struct iommu_domain_ops *ops = domain->ops;
2603 	size_t len = 0, mapped = 0;
2604 	phys_addr_t start;
2605 	unsigned int i = 0;
2606 	int ret;
2607 
2608 	might_sleep_if(gfpflags_allow_blocking(gfp));
2609 
2610 	/* Discourage passing strange GFP flags */
2611 	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
2612 				__GFP_HIGHMEM)))
2613 		return -EINVAL;
2614 
2615 	while (i <= nents) {
2616 		phys_addr_t s_phys = sg_phys(sg);
2617 
2618 		if (len && s_phys != start + len) {
2619 			ret = __iommu_map(domain, iova + mapped, start,
2620 					len, prot, gfp);
2621 
2622 			if (ret)
2623 				goto out_err;
2624 
2625 			mapped += len;
2626 			len = 0;
2627 		}
2628 
2629 		if (sg_dma_is_bus_address(sg))
2630 			goto next;
2631 
2632 		if (len) {
2633 			len += sg->length;
2634 		} else {
2635 			len = sg->length;
2636 			start = s_phys;
2637 		}
2638 
2639 next:
2640 		if (++i < nents)
2641 			sg = sg_next(sg);
2642 	}
2643 
2644 	if (ops->iotlb_sync_map) {
2645 		ret = ops->iotlb_sync_map(domain, iova, mapped);
2646 		if (ret)
2647 			goto out_err;
2648 	}
2649 	return mapped;
2650 
2651 out_err:
2652 	/* undo mappings already done */
2653 	iommu_unmap(domain, iova, mapped);
2654 
2655 	return ret;
2656 }
2657 EXPORT_SYMBOL_GPL(iommu_map_sg);
2658 
2659 /**
2660  * report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
2661  * @domain: the iommu domain where the fault has happened
2662  * @dev: the device where the fault has happened
2663  * @iova: the faulting address
2664  * @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
2665  *
2666  * This function should be called by the low-level IOMMU implementations
2667  * whenever IOMMU faults happen, to allow high-level users, that are
2668  * interested in such events, to know about them.
2669  *
2670  * This event may be useful for several possible use cases:
2671  * - mere logging of the event
2672  * - dynamic TLB/PTE loading
2673  * - if restarting of the faulting device is required
2674  *
2675  * Returns 0 on success and an appropriate error code otherwise (if dynamic
2676  * PTE/TLB loading will one day be supported, implementations will be able
2677  * to tell whether it succeeded or not according to this return value).
2678  *
2679  * Specifically, -ENOSYS is returned if a fault handler isn't installed
2680  * (though fault handlers can also return -ENOSYS, in case they want to
2681  * elicit the default behavior of the IOMMU drivers).
2682  */
report_iommu_fault(struct iommu_domain * domain,struct device * dev,unsigned long iova,int flags)2683 int report_iommu_fault(struct iommu_domain *domain, struct device *dev,
2684 		       unsigned long iova, int flags)
2685 {
2686 	int ret = -ENOSYS;
2687 
2688 	/*
2689 	 * if upper layers showed interest and installed a fault handler,
2690 	 * invoke it.
2691 	 */
2692 	if (domain->handler)
2693 		ret = domain->handler(domain, dev, iova, flags,
2694 						domain->handler_token);
2695 
2696 	trace_io_page_fault(dev, iova, flags);
2697 	return ret;
2698 }
2699 EXPORT_SYMBOL_GPL(report_iommu_fault);
2700 
iommu_init(void)2701 static int __init iommu_init(void)
2702 {
2703 	iommu_group_kset = kset_create_and_add("iommu_groups",
2704 					       NULL, kernel_kobj);
2705 	BUG_ON(!iommu_group_kset);
2706 
2707 	iommu_debugfs_setup();
2708 
2709 	return 0;
2710 }
2711 core_initcall(iommu_init);
2712 
iommu_set_pgtable_quirks(struct iommu_domain * domain,unsigned long quirk)2713 int iommu_set_pgtable_quirks(struct iommu_domain *domain,
2714 		unsigned long quirk)
2715 {
2716 	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
2717 		return -EINVAL;
2718 	if (!domain->ops->set_pgtable_quirks)
2719 		return -EINVAL;
2720 	return domain->ops->set_pgtable_quirks(domain, quirk);
2721 }
2722 EXPORT_SYMBOL_GPL(iommu_set_pgtable_quirks);
2723 
2724 /**
2725  * iommu_get_resv_regions - get reserved regions
2726  * @dev: device for which to get reserved regions
2727  * @list: reserved region list for device
2728  *
2729  * This returns a list of reserved IOVA regions specific to this device.
2730  * A domain user should not map IOVA in these ranges.
2731  */
iommu_get_resv_regions(struct device * dev,struct list_head * list)2732 void iommu_get_resv_regions(struct device *dev, struct list_head *list)
2733 {
2734 	const struct iommu_ops *ops = dev_iommu_ops(dev);
2735 
2736 	if (ops->get_resv_regions)
2737 		ops->get_resv_regions(dev, list);
2738 }
2739 EXPORT_SYMBOL_GPL(iommu_get_resv_regions);
2740 
2741 /**
2742  * iommu_put_resv_regions - release reserved regions
2743  * @dev: device for which to free reserved regions
2744  * @list: reserved region list for device
2745  *
2746  * This releases a reserved region list acquired by iommu_get_resv_regions().
2747  */
iommu_put_resv_regions(struct device * dev,struct list_head * list)2748 void iommu_put_resv_regions(struct device *dev, struct list_head *list)
2749 {
2750 	struct iommu_resv_region *entry, *next;
2751 
2752 	list_for_each_entry_safe(entry, next, list, list) {
2753 		if (entry->free)
2754 			entry->free(dev, entry);
2755 		else
2756 			kfree(entry);
2757 	}
2758 }
2759 EXPORT_SYMBOL(iommu_put_resv_regions);
2760 
iommu_alloc_resv_region(phys_addr_t start,size_t length,int prot,enum iommu_resv_type type,gfp_t gfp)2761 struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
2762 						  size_t length, int prot,
2763 						  enum iommu_resv_type type,
2764 						  gfp_t gfp)
2765 {
2766 	struct iommu_resv_region *region;
2767 
2768 	region = kzalloc(sizeof(*region), gfp);
2769 	if (!region)
2770 		return NULL;
2771 
2772 	INIT_LIST_HEAD(&region->list);
2773 	region->start = start;
2774 	region->length = length;
2775 	region->prot = prot;
2776 	region->type = type;
2777 	return region;
2778 }
2779 EXPORT_SYMBOL_GPL(iommu_alloc_resv_region);
2780 
iommu_set_default_passthrough(bool cmd_line)2781 void iommu_set_default_passthrough(bool cmd_line)
2782 {
2783 	if (cmd_line)
2784 		iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API;
2785 	iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
2786 }
2787 
iommu_set_default_translated(bool cmd_line)2788 void iommu_set_default_translated(bool cmd_line)
2789 {
2790 	if (cmd_line)
2791 		iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API;
2792 	iommu_def_domain_type = IOMMU_DOMAIN_DMA;
2793 }
2794 
iommu_default_passthrough(void)2795 bool iommu_default_passthrough(void)
2796 {
2797 	return iommu_def_domain_type == IOMMU_DOMAIN_IDENTITY;
2798 }
2799 EXPORT_SYMBOL_GPL(iommu_default_passthrough);
2800 
iommu_ops_from_fwnode(const struct fwnode_handle * fwnode)2801 const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode)
2802 {
2803 	const struct iommu_ops *ops = NULL;
2804 	struct iommu_device *iommu;
2805 
2806 	spin_lock(&iommu_device_lock);
2807 	list_for_each_entry(iommu, &iommu_device_list, list)
2808 		if (iommu->fwnode == fwnode) {
2809 			ops = iommu->ops;
2810 			break;
2811 		}
2812 	spin_unlock(&iommu_device_lock);
2813 	return ops;
2814 }
2815 
iommu_fwspec_init(struct device * dev,struct fwnode_handle * iommu_fwnode)2816 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode)
2817 {
2818 	const struct iommu_ops *ops = iommu_ops_from_fwnode(iommu_fwnode);
2819 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
2820 
2821 	if (!ops)
2822 		return -EPROBE_DEFER;
2823 
2824 	if (fwspec)
2825 		return ops == iommu_fwspec_ops(fwspec) ? 0 : -EINVAL;
2826 
2827 	if (!dev_iommu_get(dev))
2828 		return -ENOMEM;
2829 
2830 	/* Preallocate for the overwhelmingly common case of 1 ID */
2831 	fwspec = kzalloc(struct_size(fwspec, ids, 1), GFP_KERNEL);
2832 	if (!fwspec)
2833 		return -ENOMEM;
2834 
2835 	fwnode_handle_get(iommu_fwnode);
2836 	fwspec->iommu_fwnode = iommu_fwnode;
2837 	dev_iommu_fwspec_set(dev, fwspec);
2838 	return 0;
2839 }
2840 EXPORT_SYMBOL_GPL(iommu_fwspec_init);
2841 
iommu_fwspec_free(struct device * dev)2842 void iommu_fwspec_free(struct device *dev)
2843 {
2844 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
2845 
2846 	if (fwspec) {
2847 		fwnode_handle_put(fwspec->iommu_fwnode);
2848 		kfree(fwspec);
2849 		dev_iommu_fwspec_set(dev, NULL);
2850 	}
2851 }
2852 EXPORT_SYMBOL_GPL(iommu_fwspec_free);
2853 
iommu_fwspec_add_ids(struct device * dev,const u32 * ids,int num_ids)2854 int iommu_fwspec_add_ids(struct device *dev, const u32 *ids, int num_ids)
2855 {
2856 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
2857 	int i, new_num;
2858 
2859 	if (!fwspec)
2860 		return -EINVAL;
2861 
2862 	new_num = fwspec->num_ids + num_ids;
2863 	if (new_num > 1) {
2864 		fwspec = krealloc(fwspec, struct_size(fwspec, ids, new_num),
2865 				  GFP_KERNEL);
2866 		if (!fwspec)
2867 			return -ENOMEM;
2868 
2869 		dev_iommu_fwspec_set(dev, fwspec);
2870 	}
2871 
2872 	for (i = 0; i < num_ids; i++)
2873 		fwspec->ids[fwspec->num_ids + i] = ids[i];
2874 
2875 	fwspec->num_ids = new_num;
2876 	return 0;
2877 }
2878 EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
2879 
2880 /*
2881  * Per device IOMMU features.
2882  */
iommu_dev_enable_feature(struct device * dev,enum iommu_dev_features feat)2883 int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
2884 {
2885 	if (dev_has_iommu(dev)) {
2886 		const struct iommu_ops *ops = dev_iommu_ops(dev);
2887 
2888 		if (ops->dev_enable_feat)
2889 			return ops->dev_enable_feat(dev, feat);
2890 	}
2891 
2892 	return -ENODEV;
2893 }
2894 EXPORT_SYMBOL_GPL(iommu_dev_enable_feature);
2895 
2896 /*
2897  * The device drivers should do the necessary cleanups before calling this.
2898  */
iommu_dev_disable_feature(struct device * dev,enum iommu_dev_features feat)2899 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
2900 {
2901 	if (dev_has_iommu(dev)) {
2902 		const struct iommu_ops *ops = dev_iommu_ops(dev);
2903 
2904 		if (ops->dev_disable_feat)
2905 			return ops->dev_disable_feat(dev, feat);
2906 	}
2907 
2908 	return -EBUSY;
2909 }
2910 EXPORT_SYMBOL_GPL(iommu_dev_disable_feature);
2911 
2912 /**
2913  * iommu_setup_default_domain - Set the default_domain for the group
2914  * @group: Group to change
2915  * @target_type: Domain type to set as the default_domain
2916  *
2917  * Allocate a default domain and set it as the current domain on the group. If
2918  * the group already has a default domain it will be changed to the target_type.
2919  * When target_type is 0 the default domain is selected based on driver and
2920  * system preferences.
2921  */
iommu_setup_default_domain(struct iommu_group * group,int target_type)2922 static int iommu_setup_default_domain(struct iommu_group *group,
2923 				      int target_type)
2924 {
2925 	struct iommu_domain *old_dom = group->default_domain;
2926 	struct group_device *gdev;
2927 	struct iommu_domain *dom;
2928 	bool direct_failed;
2929 	int req_type;
2930 	int ret;
2931 
2932 	lockdep_assert_held(&group->mutex);
2933 
2934 	req_type = iommu_get_default_domain_type(group, target_type);
2935 	if (req_type < 0)
2936 		return -EINVAL;
2937 
2938 	dom = iommu_group_alloc_default_domain(group, req_type);
2939 	if (IS_ERR(dom))
2940 		return PTR_ERR(dom);
2941 
2942 	if (group->default_domain == dom)
2943 		return 0;
2944 
2945 	if (iommu_is_dma_domain(dom)) {
2946 		ret = iommu_get_dma_cookie(dom);
2947 		if (ret) {
2948 			iommu_domain_free(dom);
2949 			return ret;
2950 		}
2951 	}
2952 
2953 	/*
2954 	 * IOMMU_RESV_DIRECT and IOMMU_RESV_DIRECT_RELAXABLE regions must be
2955 	 * mapped before their device is attached, in order to guarantee
2956 	 * continuity with any FW activity
2957 	 */
2958 	direct_failed = false;
2959 	for_each_group_device(group, gdev) {
2960 		if (iommu_create_device_direct_mappings(dom, gdev->dev)) {
2961 			direct_failed = true;
2962 			dev_warn_once(
2963 				gdev->dev->iommu->iommu_dev->dev,
2964 				"IOMMU driver was not able to establish FW requested direct mapping.");
2965 		}
2966 	}
2967 
2968 	/* We must set default_domain early for __iommu_device_set_domain */
2969 	group->default_domain = dom;
2970 	if (!group->domain) {
2971 		/*
2972 		 * Drivers are not allowed to fail the first domain attach.
2973 		 * The only way to recover from this is to fail attaching the
2974 		 * iommu driver and call ops->release_device. Put the domain
2975 		 * in group->default_domain so it is freed after.
2976 		 */
2977 		ret = __iommu_group_set_domain_internal(
2978 			group, dom, IOMMU_SET_DOMAIN_MUST_SUCCEED);
2979 		if (WARN_ON(ret))
2980 			goto out_free_old;
2981 	} else {
2982 		ret = __iommu_group_set_domain(group, dom);
2983 		if (ret)
2984 			goto err_restore_def_domain;
2985 	}
2986 
2987 	/*
2988 	 * Drivers are supposed to allow mappings to be installed in a domain
2989 	 * before device attachment, but some don't. Hack around this defect by
2990 	 * trying again after attaching. If this happens it means the device
2991 	 * will not continuously have the IOMMU_RESV_DIRECT map.
2992 	 */
2993 	if (direct_failed) {
2994 		for_each_group_device(group, gdev) {
2995 			ret = iommu_create_device_direct_mappings(dom, gdev->dev);
2996 			if (ret)
2997 				goto err_restore_domain;
2998 		}
2999 	}
3000 
3001 out_free_old:
3002 	if (old_dom)
3003 		iommu_domain_free(old_dom);
3004 	return ret;
3005 
3006 err_restore_domain:
3007 	if (old_dom)
3008 		__iommu_group_set_domain_internal(
3009 			group, old_dom, IOMMU_SET_DOMAIN_MUST_SUCCEED);
3010 err_restore_def_domain:
3011 	if (old_dom) {
3012 		iommu_domain_free(dom);
3013 		group->default_domain = old_dom;
3014 	}
3015 	return ret;
3016 }
3017 
3018 /*
3019  * Changing the default domain through sysfs requires the users to unbind the
3020  * drivers from the devices in the iommu group, except for a DMA -> DMA-FQ
3021  * transition. Return failure if this isn't met.
3022  *
3023  * We need to consider the race between this and the device release path.
3024  * group->mutex is used here to guarantee that the device release path
3025  * will not be entered at the same time.
3026  */
iommu_group_store_type(struct iommu_group * group,const char * buf,size_t count)3027 static ssize_t iommu_group_store_type(struct iommu_group *group,
3028 				      const char *buf, size_t count)
3029 {
3030 	struct group_device *gdev;
3031 	int ret, req_type;
3032 
3033 	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
3034 		return -EACCES;
3035 
3036 	if (WARN_ON(!group) || !group->default_domain)
3037 		return -EINVAL;
3038 
3039 	if (sysfs_streq(buf, "identity"))
3040 		req_type = IOMMU_DOMAIN_IDENTITY;
3041 	else if (sysfs_streq(buf, "DMA"))
3042 		req_type = IOMMU_DOMAIN_DMA;
3043 	else if (sysfs_streq(buf, "DMA-FQ"))
3044 		req_type = IOMMU_DOMAIN_DMA_FQ;
3045 	else if (sysfs_streq(buf, "auto"))
3046 		req_type = 0;
3047 	else
3048 		return -EINVAL;
3049 
3050 	mutex_lock(&group->mutex);
3051 	/* We can bring up a flush queue without tearing down the domain. */
3052 	if (req_type == IOMMU_DOMAIN_DMA_FQ &&
3053 	    group->default_domain->type == IOMMU_DOMAIN_DMA) {
3054 		ret = iommu_dma_init_fq(group->default_domain);
3055 		if (ret)
3056 			goto out_unlock;
3057 
3058 		group->default_domain->type = IOMMU_DOMAIN_DMA_FQ;
3059 		ret = count;
3060 		goto out_unlock;
3061 	}
3062 
3063 	/* Otherwise, ensure that device exists and no driver is bound. */
3064 	if (list_empty(&group->devices) || group->owner_cnt) {
3065 		ret = -EPERM;
3066 		goto out_unlock;
3067 	}
3068 
3069 	ret = iommu_setup_default_domain(group, req_type);
3070 	if (ret)
3071 		goto out_unlock;
3072 
3073 	/* Make sure dma_ops is appropriatley set */
3074 	for_each_group_device(group, gdev)
3075 		iommu_setup_dma_ops(gdev->dev);
3076 
3077 out_unlock:
3078 	mutex_unlock(&group->mutex);
3079 	return ret ?: count;
3080 }
3081 
3082 /**
3083  * iommu_device_use_default_domain() - Device driver wants to handle device
3084  *                                     DMA through the kernel DMA API.
3085  * @dev: The device.
3086  *
3087  * The device driver about to bind @dev wants to do DMA through the kernel
3088  * DMA API. Return 0 if it is allowed, otherwise an error.
3089  */
iommu_device_use_default_domain(struct device * dev)3090 int iommu_device_use_default_domain(struct device *dev)
3091 {
3092 	/* Caller is the driver core during the pre-probe path */
3093 	struct iommu_group *group = dev->iommu_group;
3094 	int ret = 0;
3095 
3096 	if (!group)
3097 		return 0;
3098 
3099 	mutex_lock(&group->mutex);
3100 	if (group->owner_cnt) {
3101 		if (group->domain != group->default_domain || group->owner ||
3102 		    !xa_empty(&group->pasid_array)) {
3103 			ret = -EBUSY;
3104 			goto unlock_out;
3105 		}
3106 	}
3107 
3108 	group->owner_cnt++;
3109 
3110 unlock_out:
3111 	mutex_unlock(&group->mutex);
3112 	return ret;
3113 }
3114 
3115 /**
3116  * iommu_device_unuse_default_domain() - Device driver stops handling device
3117  *                                       DMA through the kernel DMA API.
3118  * @dev: The device.
3119  *
3120  * The device driver doesn't want to do DMA through kernel DMA API anymore.
3121  * It must be called after iommu_device_use_default_domain().
3122  */
iommu_device_unuse_default_domain(struct device * dev)3123 void iommu_device_unuse_default_domain(struct device *dev)
3124 {
3125 	/* Caller is the driver core during the post-probe path */
3126 	struct iommu_group *group = dev->iommu_group;
3127 
3128 	if (!group)
3129 		return;
3130 
3131 	mutex_lock(&group->mutex);
3132 	if (!WARN_ON(!group->owner_cnt || !xa_empty(&group->pasid_array)))
3133 		group->owner_cnt--;
3134 
3135 	mutex_unlock(&group->mutex);
3136 }
3137 
__iommu_group_alloc_blocking_domain(struct iommu_group * group)3138 static int __iommu_group_alloc_blocking_domain(struct iommu_group *group)
3139 {
3140 	struct device *dev = iommu_group_first_dev(group);
3141 	const struct iommu_ops *ops = dev_iommu_ops(dev);
3142 	struct iommu_domain *domain;
3143 
3144 	if (group->blocking_domain)
3145 		return 0;
3146 
3147 	if (ops->blocked_domain) {
3148 		group->blocking_domain = ops->blocked_domain;
3149 		return 0;
3150 	}
3151 
3152 	/*
3153 	 * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED create an
3154 	 * empty PAGING domain instead.
3155 	 */
3156 	domain = iommu_paging_domain_alloc(dev);
3157 	if (IS_ERR(domain))
3158 		return PTR_ERR(domain);
3159 	group->blocking_domain = domain;
3160 	return 0;
3161 }
3162 
__iommu_take_dma_ownership(struct iommu_group * group,void * owner)3163 static int __iommu_take_dma_ownership(struct iommu_group *group, void *owner)
3164 {
3165 	int ret;
3166 
3167 	if ((group->domain && group->domain != group->default_domain) ||
3168 	    !xa_empty(&group->pasid_array))
3169 		return -EBUSY;
3170 
3171 	ret = __iommu_group_alloc_blocking_domain(group);
3172 	if (ret)
3173 		return ret;
3174 	ret = __iommu_group_set_domain(group, group->blocking_domain);
3175 	if (ret)
3176 		return ret;
3177 
3178 	group->owner = owner;
3179 	group->owner_cnt++;
3180 	return 0;
3181 }
3182 
3183 /**
3184  * iommu_group_claim_dma_owner() - Set DMA ownership of a group
3185  * @group: The group.
3186  * @owner: Caller specified pointer. Used for exclusive ownership.
3187  *
3188  * This is to support backward compatibility for vfio which manages the dma
3189  * ownership in iommu_group level. New invocations on this interface should be
3190  * prohibited. Only a single owner may exist for a group.
3191  */
iommu_group_claim_dma_owner(struct iommu_group * group,void * owner)3192 int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner)
3193 {
3194 	int ret = 0;
3195 
3196 	if (WARN_ON(!owner))
3197 		return -EINVAL;
3198 
3199 	mutex_lock(&group->mutex);
3200 	if (group->owner_cnt) {
3201 		ret = -EPERM;
3202 		goto unlock_out;
3203 	}
3204 
3205 	ret = __iommu_take_dma_ownership(group, owner);
3206 unlock_out:
3207 	mutex_unlock(&group->mutex);
3208 
3209 	return ret;
3210 }
3211 EXPORT_SYMBOL_GPL(iommu_group_claim_dma_owner);
3212 
3213 /**
3214  * iommu_device_claim_dma_owner() - Set DMA ownership of a device
3215  * @dev: The device.
3216  * @owner: Caller specified pointer. Used for exclusive ownership.
3217  *
3218  * Claim the DMA ownership of a device. Multiple devices in the same group may
3219  * concurrently claim ownership if they present the same owner value. Returns 0
3220  * on success and error code on failure
3221  */
iommu_device_claim_dma_owner(struct device * dev,void * owner)3222 int iommu_device_claim_dma_owner(struct device *dev, void *owner)
3223 {
3224 	/* Caller must be a probed driver on dev */
3225 	struct iommu_group *group = dev->iommu_group;
3226 	int ret = 0;
3227 
3228 	if (WARN_ON(!owner))
3229 		return -EINVAL;
3230 
3231 	if (!group)
3232 		return -ENODEV;
3233 
3234 	mutex_lock(&group->mutex);
3235 	if (group->owner_cnt) {
3236 		if (group->owner != owner) {
3237 			ret = -EPERM;
3238 			goto unlock_out;
3239 		}
3240 		group->owner_cnt++;
3241 		goto unlock_out;
3242 	}
3243 
3244 	ret = __iommu_take_dma_ownership(group, owner);
3245 unlock_out:
3246 	mutex_unlock(&group->mutex);
3247 	return ret;
3248 }
3249 EXPORT_SYMBOL_GPL(iommu_device_claim_dma_owner);
3250 
__iommu_release_dma_ownership(struct iommu_group * group)3251 static void __iommu_release_dma_ownership(struct iommu_group *group)
3252 {
3253 	if (WARN_ON(!group->owner_cnt || !group->owner ||
3254 		    !xa_empty(&group->pasid_array)))
3255 		return;
3256 
3257 	group->owner_cnt = 0;
3258 	group->owner = NULL;
3259 	__iommu_group_set_domain_nofail(group, group->default_domain);
3260 }
3261 
3262 /**
3263  * iommu_group_release_dma_owner() - Release DMA ownership of a group
3264  * @group: The group
3265  *
3266  * Release the DMA ownership claimed by iommu_group_claim_dma_owner().
3267  */
iommu_group_release_dma_owner(struct iommu_group * group)3268 void iommu_group_release_dma_owner(struct iommu_group *group)
3269 {
3270 	mutex_lock(&group->mutex);
3271 	__iommu_release_dma_ownership(group);
3272 	mutex_unlock(&group->mutex);
3273 }
3274 EXPORT_SYMBOL_GPL(iommu_group_release_dma_owner);
3275 
3276 /**
3277  * iommu_device_release_dma_owner() - Release DMA ownership of a device
3278  * @dev: The device.
3279  *
3280  * Release the DMA ownership claimed by iommu_device_claim_dma_owner().
3281  */
iommu_device_release_dma_owner(struct device * dev)3282 void iommu_device_release_dma_owner(struct device *dev)
3283 {
3284 	/* Caller must be a probed driver on dev */
3285 	struct iommu_group *group = dev->iommu_group;
3286 
3287 	mutex_lock(&group->mutex);
3288 	if (group->owner_cnt > 1)
3289 		group->owner_cnt--;
3290 	else
3291 		__iommu_release_dma_ownership(group);
3292 	mutex_unlock(&group->mutex);
3293 }
3294 EXPORT_SYMBOL_GPL(iommu_device_release_dma_owner);
3295 
3296 /**
3297  * iommu_group_dma_owner_claimed() - Query group dma ownership status
3298  * @group: The group.
3299  *
3300  * This provides status query on a given group. It is racy and only for
3301  * non-binding status reporting.
3302  */
iommu_group_dma_owner_claimed(struct iommu_group * group)3303 bool iommu_group_dma_owner_claimed(struct iommu_group *group)
3304 {
3305 	unsigned int user;
3306 
3307 	mutex_lock(&group->mutex);
3308 	user = group->owner_cnt;
3309 	mutex_unlock(&group->mutex);
3310 
3311 	return user;
3312 }
3313 EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
3314 
__iommu_set_group_pasid(struct iommu_domain * domain,struct iommu_group * group,ioasid_t pasid)3315 static int __iommu_set_group_pasid(struct iommu_domain *domain,
3316 				   struct iommu_group *group, ioasid_t pasid)
3317 {
3318 	struct group_device *device, *last_gdev;
3319 	int ret;
3320 
3321 	for_each_group_device(group, device) {
3322 		ret = domain->ops->set_dev_pasid(domain, device->dev,
3323 						 pasid, NULL);
3324 		if (ret)
3325 			goto err_revert;
3326 	}
3327 
3328 	return 0;
3329 
3330 err_revert:
3331 	last_gdev = device;
3332 	for_each_group_device(group, device) {
3333 		const struct iommu_ops *ops = dev_iommu_ops(device->dev);
3334 
3335 		if (device == last_gdev)
3336 			break;
3337 		ops->remove_dev_pasid(device->dev, pasid, domain);
3338 	}
3339 	return ret;
3340 }
3341 
__iommu_remove_group_pasid(struct iommu_group * group,ioasid_t pasid,struct iommu_domain * domain)3342 static void __iommu_remove_group_pasid(struct iommu_group *group,
3343 				       ioasid_t pasid,
3344 				       struct iommu_domain *domain)
3345 {
3346 	struct group_device *device;
3347 	const struct iommu_ops *ops;
3348 
3349 	for_each_group_device(group, device) {
3350 		ops = dev_iommu_ops(device->dev);
3351 		ops->remove_dev_pasid(device->dev, pasid, domain);
3352 	}
3353 }
3354 
3355 /*
3356  * iommu_attach_device_pasid() - Attach a domain to pasid of device
3357  * @domain: the iommu domain.
3358  * @dev: the attached device.
3359  * @pasid: the pasid of the device.
3360  * @handle: the attach handle.
3361  *
3362  * Return: 0 on success, or an error.
3363  */
iommu_attach_device_pasid(struct iommu_domain * domain,struct device * dev,ioasid_t pasid,struct iommu_attach_handle * handle)3364 int iommu_attach_device_pasid(struct iommu_domain *domain,
3365 			      struct device *dev, ioasid_t pasid,
3366 			      struct iommu_attach_handle *handle)
3367 {
3368 	/* Caller must be a probed driver on dev */
3369 	struct iommu_group *group = dev->iommu_group;
3370 	struct group_device *device;
3371 	int ret;
3372 
3373 	if (!domain->ops->set_dev_pasid)
3374 		return -EOPNOTSUPP;
3375 
3376 	if (!group)
3377 		return -ENODEV;
3378 
3379 	if (!dev_has_iommu(dev) || dev_iommu_ops(dev) != domain->owner ||
3380 	    pasid == IOMMU_NO_PASID)
3381 		return -EINVAL;
3382 
3383 	mutex_lock(&group->mutex);
3384 	for_each_group_device(group, device) {
3385 		if (pasid >= device->dev->iommu->max_pasids) {
3386 			ret = -EINVAL;
3387 			goto out_unlock;
3388 		}
3389 	}
3390 
3391 	if (handle)
3392 		handle->domain = domain;
3393 
3394 	ret = xa_insert(&group->pasid_array, pasid, handle, GFP_KERNEL);
3395 	if (ret)
3396 		goto out_unlock;
3397 
3398 	ret = __iommu_set_group_pasid(domain, group, pasid);
3399 	if (ret)
3400 		xa_erase(&group->pasid_array, pasid);
3401 out_unlock:
3402 	mutex_unlock(&group->mutex);
3403 	return ret;
3404 }
3405 EXPORT_SYMBOL_GPL(iommu_attach_device_pasid);
3406 
3407 /*
3408  * iommu_detach_device_pasid() - Detach the domain from pasid of device
3409  * @domain: the iommu domain.
3410  * @dev: the attached device.
3411  * @pasid: the pasid of the device.
3412  *
3413  * The @domain must have been attached to @pasid of the @dev with
3414  * iommu_attach_device_pasid().
3415  */
iommu_detach_device_pasid(struct iommu_domain * domain,struct device * dev,ioasid_t pasid)3416 void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
3417 			       ioasid_t pasid)
3418 {
3419 	/* Caller must be a probed driver on dev */
3420 	struct iommu_group *group = dev->iommu_group;
3421 
3422 	mutex_lock(&group->mutex);
3423 	__iommu_remove_group_pasid(group, pasid, domain);
3424 	xa_erase(&group->pasid_array, pasid);
3425 	mutex_unlock(&group->mutex);
3426 }
3427 EXPORT_SYMBOL_GPL(iommu_detach_device_pasid);
3428 
iommu_alloc_global_pasid(struct device * dev)3429 ioasid_t iommu_alloc_global_pasid(struct device *dev)
3430 {
3431 	int ret;
3432 
3433 	/* max_pasids == 0 means that the device does not support PASID */
3434 	if (!dev->iommu->max_pasids)
3435 		return IOMMU_PASID_INVALID;
3436 
3437 	/*
3438 	 * max_pasids is set up by vendor driver based on number of PASID bits
3439 	 * supported but the IDA allocation is inclusive.
3440 	 */
3441 	ret = ida_alloc_range(&iommu_global_pasid_ida, IOMMU_FIRST_GLOBAL_PASID,
3442 			      dev->iommu->max_pasids - 1, GFP_KERNEL);
3443 	return ret < 0 ? IOMMU_PASID_INVALID : ret;
3444 }
3445 EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid);
3446 
iommu_free_global_pasid(ioasid_t pasid)3447 void iommu_free_global_pasid(ioasid_t pasid)
3448 {
3449 	if (WARN_ON(pasid == IOMMU_PASID_INVALID))
3450 		return;
3451 
3452 	ida_free(&iommu_global_pasid_ida, pasid);
3453 }
3454 EXPORT_SYMBOL_GPL(iommu_free_global_pasid);
3455 
3456 /**
3457  * iommu_attach_handle_get - Return the attach handle
3458  * @group: the iommu group that domain was attached to
3459  * @pasid: the pasid within the group
3460  * @type: matched domain type, 0 for any match
3461  *
3462  * Return handle or ERR_PTR(-ENOENT) on none, ERR_PTR(-EBUSY) on mismatch.
3463  *
3464  * Return the attach handle to the caller. The life cycle of an iommu attach
3465  * handle is from the time when the domain is attached to the time when the
3466  * domain is detached. Callers are required to synchronize the call of
3467  * iommu_attach_handle_get() with domain attachment and detachment. The attach
3468  * handle can only be used during its life cycle.
3469  */
3470 struct iommu_attach_handle *
iommu_attach_handle_get(struct iommu_group * group,ioasid_t pasid,unsigned int type)3471 iommu_attach_handle_get(struct iommu_group *group, ioasid_t pasid, unsigned int type)
3472 {
3473 	struct iommu_attach_handle *handle;
3474 
3475 	xa_lock(&group->pasid_array);
3476 	handle = xa_load(&group->pasid_array, pasid);
3477 	if (!handle)
3478 		handle = ERR_PTR(-ENOENT);
3479 	else if (type && handle->domain->type != type)
3480 		handle = ERR_PTR(-EBUSY);
3481 	xa_unlock(&group->pasid_array);
3482 
3483 	return handle;
3484 }
3485 EXPORT_SYMBOL_NS_GPL(iommu_attach_handle_get, "IOMMUFD_INTERNAL");
3486 
3487 /**
3488  * iommu_attach_group_handle - Attach an IOMMU domain to an IOMMU group
3489  * @domain: IOMMU domain to attach
3490  * @group: IOMMU group that will be attached
3491  * @handle: attach handle
3492  *
3493  * Returns 0 on success and error code on failure.
3494  *
3495  * This is a variant of iommu_attach_group(). It allows the caller to provide
3496  * an attach handle and use it when the domain is attached. This is currently
3497  * used by IOMMUFD to deliver the I/O page faults.
3498  */
iommu_attach_group_handle(struct iommu_domain * domain,struct iommu_group * group,struct iommu_attach_handle * handle)3499 int iommu_attach_group_handle(struct iommu_domain *domain,
3500 			      struct iommu_group *group,
3501 			      struct iommu_attach_handle *handle)
3502 {
3503 	int ret;
3504 
3505 	if (handle)
3506 		handle->domain = domain;
3507 
3508 	mutex_lock(&group->mutex);
3509 	ret = xa_insert(&group->pasid_array, IOMMU_NO_PASID, handle, GFP_KERNEL);
3510 	if (ret)
3511 		goto err_unlock;
3512 
3513 	ret = __iommu_attach_group(domain, group);
3514 	if (ret)
3515 		goto err_erase;
3516 	mutex_unlock(&group->mutex);
3517 
3518 	return 0;
3519 err_erase:
3520 	xa_erase(&group->pasid_array, IOMMU_NO_PASID);
3521 err_unlock:
3522 	mutex_unlock(&group->mutex);
3523 	return ret;
3524 }
3525 EXPORT_SYMBOL_NS_GPL(iommu_attach_group_handle, "IOMMUFD_INTERNAL");
3526 
3527 /**
3528  * iommu_detach_group_handle - Detach an IOMMU domain from an IOMMU group
3529  * @domain: IOMMU domain to attach
3530  * @group: IOMMU group that will be attached
3531  *
3532  * Detach the specified IOMMU domain from the specified IOMMU group.
3533  * It must be used in conjunction with iommu_attach_group_handle().
3534  */
iommu_detach_group_handle(struct iommu_domain * domain,struct iommu_group * group)3535 void iommu_detach_group_handle(struct iommu_domain *domain,
3536 			       struct iommu_group *group)
3537 {
3538 	mutex_lock(&group->mutex);
3539 	__iommu_group_set_core_domain(group);
3540 	xa_erase(&group->pasid_array, IOMMU_NO_PASID);
3541 	mutex_unlock(&group->mutex);
3542 }
3543 EXPORT_SYMBOL_NS_GPL(iommu_detach_group_handle, "IOMMUFD_INTERNAL");
3544 
3545 /**
3546  * iommu_replace_group_handle - replace the domain that a group is attached to
3547  * @group: IOMMU group that will be attached to the new domain
3548  * @new_domain: new IOMMU domain to replace with
3549  * @handle: attach handle
3550  *
3551  * This is a variant of iommu_group_replace_domain(). It allows the caller to
3552  * provide an attach handle for the new domain and use it when the domain is
3553  * attached.
3554  */
iommu_replace_group_handle(struct iommu_group * group,struct iommu_domain * new_domain,struct iommu_attach_handle * handle)3555 int iommu_replace_group_handle(struct iommu_group *group,
3556 			       struct iommu_domain *new_domain,
3557 			       struct iommu_attach_handle *handle)
3558 {
3559 	void *curr;
3560 	int ret;
3561 
3562 	if (!new_domain)
3563 		return -EINVAL;
3564 
3565 	mutex_lock(&group->mutex);
3566 	if (handle) {
3567 		ret = xa_reserve(&group->pasid_array, IOMMU_NO_PASID, GFP_KERNEL);
3568 		if (ret)
3569 			goto err_unlock;
3570 		handle->domain = new_domain;
3571 	}
3572 
3573 	ret = __iommu_group_set_domain(group, new_domain);
3574 	if (ret)
3575 		goto err_release;
3576 
3577 	curr = xa_store(&group->pasid_array, IOMMU_NO_PASID, handle, GFP_KERNEL);
3578 	WARN_ON(xa_is_err(curr));
3579 
3580 	mutex_unlock(&group->mutex);
3581 
3582 	return 0;
3583 err_release:
3584 	xa_release(&group->pasid_array, IOMMU_NO_PASID);
3585 err_unlock:
3586 	mutex_unlock(&group->mutex);
3587 	return ret;
3588 }
3589 EXPORT_SYMBOL_NS_GPL(iommu_replace_group_handle, "IOMMUFD_INTERNAL");
3590