1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2014 Intel Corp.
4  * Author: Jiang Liu <jiang.liu@linux.intel.com>
5  *
6  * This file is licensed under GPLv2.
7  *
8  * This file contains common code to support Message Signaled Interrupts for
9  * PCI compatible and non PCI compatible devices.
10  */
11 #include <linux/device.h>
12 #include <linux/irq.h>
13 #include <linux/irqdomain.h>
14 #include <linux/msi.h>
15 #include <linux/mutex.h>
16 #include <linux/pci.h>
17 #include <linux/slab.h>
18 #include <linux/sysfs.h>
19 #include <linux/types.h>
20 #include <linux/xarray.h>
21 
22 #include "internals.h"
23 
24 /**
25  * struct msi_device_data - MSI per device data
26  * @properties:		MSI properties which are interesting to drivers
27  * @mutex:		Mutex protecting the MSI descriptor store
28  * @__domains:		Internal data for per device MSI domains
29  * @__iter_idx:		Index to search the next entry for iterators
30  */
31 struct msi_device_data {
32 	unsigned long			properties;
33 	struct mutex			mutex;
34 	struct msi_dev_domain		__domains[MSI_MAX_DEVICE_IRQDOMAINS];
35 	unsigned long			__iter_idx;
36 };
37 
38 /**
39  * struct msi_ctrl - MSI internal management control structure
40  * @domid:	ID of the domain on which management operations should be done
41  * @first:	First (hardware) slot index to operate on
42  * @last:	Last (hardware) slot index to operate on
43  * @nirqs:	The number of Linux interrupts to allocate. Can be larger
44  *		than the range due to PCI/multi-MSI.
45  */
46 struct msi_ctrl {
47 	unsigned int			domid;
48 	unsigned int			first;
49 	unsigned int			last;
50 	unsigned int			nirqs;
51 };
52 
53 /* Invalid Xarray index which is outside of any searchable range */
54 #define MSI_XA_MAX_INDEX	(ULONG_MAX - 1)
55 /* The maximum domain size */
56 #define MSI_XA_DOMAIN_SIZE	(MSI_MAX_INDEX + 1)
57 
58 static void msi_domain_free_locked(struct device *dev, struct msi_ctrl *ctrl);
59 static unsigned int msi_domain_get_hwsize(struct device *dev, unsigned int domid);
60 static inline int msi_sysfs_create_group(struct device *dev);
61 
62 
63 /**
64  * msi_alloc_desc - Allocate an initialized msi_desc
65  * @dev:	Pointer to the device for which this is allocated
66  * @nvec:	The number of vectors used in this entry
67  * @affinity:	Optional pointer to an affinity mask array size of @nvec
68  *
69  * If @affinity is not %NULL then an affinity array[@nvec] is allocated
70  * and the affinity masks and flags from @affinity are copied.
71  *
72  * Return: pointer to allocated &msi_desc on success or %NULL on failure
73  */
msi_alloc_desc(struct device * dev,int nvec,const struct irq_affinity_desc * affinity)74 static struct msi_desc *msi_alloc_desc(struct device *dev, int nvec,
75 				       const struct irq_affinity_desc *affinity)
76 {
77 	struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
78 
79 	if (!desc)
80 		return NULL;
81 
82 	desc->dev = dev;
83 	desc->nvec_used = nvec;
84 	if (affinity) {
85 		desc->affinity = kmemdup_array(affinity, nvec, sizeof(*desc->affinity), GFP_KERNEL);
86 		if (!desc->affinity) {
87 			kfree(desc);
88 			return NULL;
89 		}
90 	}
91 	return desc;
92 }
93 
msi_free_desc(struct msi_desc * desc)94 static void msi_free_desc(struct msi_desc *desc)
95 {
96 	kfree(desc->affinity);
97 	kfree(desc);
98 }
99 
msi_insert_desc(struct device * dev,struct msi_desc * desc,unsigned int domid,unsigned int index)100 static int msi_insert_desc(struct device *dev, struct msi_desc *desc,
101 			   unsigned int domid, unsigned int index)
102 {
103 	struct msi_device_data *md = dev->msi.data;
104 	struct xarray *xa = &md->__domains[domid].store;
105 	unsigned int hwsize;
106 	int ret;
107 
108 	hwsize = msi_domain_get_hwsize(dev, domid);
109 
110 	if (index == MSI_ANY_INDEX) {
111 		struct xa_limit limit = { .min = 0, .max = hwsize - 1 };
112 		unsigned int index;
113 
114 		/* Let the xarray allocate a free index within the limit */
115 		ret = xa_alloc(xa, &index, desc, limit, GFP_KERNEL);
116 		if (ret)
117 			goto fail;
118 
119 		desc->msi_index = index;
120 		return 0;
121 	} else {
122 		if (index >= hwsize) {
123 			ret = -ERANGE;
124 			goto fail;
125 		}
126 
127 		desc->msi_index = index;
128 		ret = xa_insert(xa, index, desc, GFP_KERNEL);
129 		if (ret)
130 			goto fail;
131 		return 0;
132 	}
133 fail:
134 	msi_free_desc(desc);
135 	return ret;
136 }
137 
138 /**
139  * msi_domain_insert_msi_desc - Allocate and initialize a MSI descriptor and
140  *				insert it at @init_desc->msi_index
141  *
142  * @dev:	Pointer to the device for which the descriptor is allocated
143  * @domid:	The id of the interrupt domain to which the desriptor is added
144  * @init_desc:	Pointer to an MSI descriptor to initialize the new descriptor
145  *
146  * Return: 0 on success or an appropriate failure code.
147  */
msi_domain_insert_msi_desc(struct device * dev,unsigned int domid,struct msi_desc * init_desc)148 int msi_domain_insert_msi_desc(struct device *dev, unsigned int domid,
149 			       struct msi_desc *init_desc)
150 {
151 	struct msi_desc *desc;
152 
153 	lockdep_assert_held(&dev->msi.data->mutex);
154 
155 	desc = msi_alloc_desc(dev, init_desc->nvec_used, init_desc->affinity);
156 	if (!desc)
157 		return -ENOMEM;
158 
159 	/* Copy type specific data to the new descriptor. */
160 	desc->pci = init_desc->pci;
161 
162 	return msi_insert_desc(dev, desc, domid, init_desc->msi_index);
163 }
164 
msi_desc_match(struct msi_desc * desc,enum msi_desc_filter filter)165 static bool msi_desc_match(struct msi_desc *desc, enum msi_desc_filter filter)
166 {
167 	switch (filter) {
168 	case MSI_DESC_ALL:
169 		return true;
170 	case MSI_DESC_NOTASSOCIATED:
171 		return !desc->irq;
172 	case MSI_DESC_ASSOCIATED:
173 		return !!desc->irq;
174 	}
175 	WARN_ON_ONCE(1);
176 	return false;
177 }
178 
msi_ctrl_valid(struct device * dev,struct msi_ctrl * ctrl)179 static bool msi_ctrl_valid(struct device *dev, struct msi_ctrl *ctrl)
180 {
181 	unsigned int hwsize;
182 
183 	if (WARN_ON_ONCE(ctrl->domid >= MSI_MAX_DEVICE_IRQDOMAINS ||
184 			 (dev->msi.domain &&
185 			  !dev->msi.data->__domains[ctrl->domid].domain)))
186 		return false;
187 
188 	hwsize = msi_domain_get_hwsize(dev, ctrl->domid);
189 	if (WARN_ON_ONCE(ctrl->first > ctrl->last ||
190 			 ctrl->first >= hwsize ||
191 			 ctrl->last >= hwsize))
192 		return false;
193 	return true;
194 }
195 
msi_domain_free_descs(struct device * dev,struct msi_ctrl * ctrl)196 static void msi_domain_free_descs(struct device *dev, struct msi_ctrl *ctrl)
197 {
198 	struct msi_desc *desc;
199 	struct xarray *xa;
200 	unsigned long idx;
201 
202 	lockdep_assert_held(&dev->msi.data->mutex);
203 
204 	if (!msi_ctrl_valid(dev, ctrl))
205 		return;
206 
207 	xa = &dev->msi.data->__domains[ctrl->domid].store;
208 	xa_for_each_range(xa, idx, desc, ctrl->first, ctrl->last) {
209 		xa_erase(xa, idx);
210 
211 		/* Leak the descriptor when it is still referenced */
212 		if (WARN_ON_ONCE(msi_desc_match(desc, MSI_DESC_ASSOCIATED)))
213 			continue;
214 		msi_free_desc(desc);
215 	}
216 }
217 
218 /**
219  * msi_domain_free_msi_descs_range - Free a range of MSI descriptors of a device in an irqdomain
220  * @dev:	Device for which to free the descriptors
221  * @domid:	Id of the domain to operate on
222  * @first:	Index to start freeing from (inclusive)
223  * @last:	Last index to be freed (inclusive)
224  */
msi_domain_free_msi_descs_range(struct device * dev,unsigned int domid,unsigned int first,unsigned int last)225 void msi_domain_free_msi_descs_range(struct device *dev, unsigned int domid,
226 				     unsigned int first, unsigned int last)
227 {
228 	struct msi_ctrl ctrl = {
229 		.domid	= domid,
230 		.first	= first,
231 		.last	= last,
232 	};
233 
234 	msi_domain_free_descs(dev, &ctrl);
235 }
236 
237 /**
238  * msi_domain_add_simple_msi_descs - Allocate and initialize MSI descriptors
239  * @dev:	Pointer to the device for which the descriptors are allocated
240  * @ctrl:	Allocation control struct
241  *
242  * Return: 0 on success or an appropriate failure code.
243  */
msi_domain_add_simple_msi_descs(struct device * dev,struct msi_ctrl * ctrl)244 static int msi_domain_add_simple_msi_descs(struct device *dev, struct msi_ctrl *ctrl)
245 {
246 	struct msi_desc *desc;
247 	unsigned int idx;
248 	int ret;
249 
250 	lockdep_assert_held(&dev->msi.data->mutex);
251 
252 	if (!msi_ctrl_valid(dev, ctrl))
253 		return -EINVAL;
254 
255 	for (idx = ctrl->first; idx <= ctrl->last; idx++) {
256 		desc = msi_alloc_desc(dev, 1, NULL);
257 		if (!desc)
258 			goto fail_mem;
259 		ret = msi_insert_desc(dev, desc, ctrl->domid, idx);
260 		if (ret)
261 			goto fail;
262 	}
263 	return 0;
264 
265 fail_mem:
266 	ret = -ENOMEM;
267 fail:
268 	msi_domain_free_descs(dev, ctrl);
269 	return ret;
270 }
271 
__get_cached_msi_msg(struct msi_desc * entry,struct msi_msg * msg)272 void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
273 {
274 	*msg = entry->msg;
275 }
276 
get_cached_msi_msg(unsigned int irq,struct msi_msg * msg)277 void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
278 {
279 	struct msi_desc *entry = irq_get_msi_desc(irq);
280 
281 	__get_cached_msi_msg(entry, msg);
282 }
283 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
284 
msi_device_data_release(struct device * dev,void * res)285 static void msi_device_data_release(struct device *dev, void *res)
286 {
287 	struct msi_device_data *md = res;
288 	int i;
289 
290 	for (i = 0; i < MSI_MAX_DEVICE_IRQDOMAINS; i++) {
291 		msi_remove_device_irq_domain(dev, i);
292 		WARN_ON_ONCE(!xa_empty(&md->__domains[i].store));
293 		xa_destroy(&md->__domains[i].store);
294 	}
295 	dev->msi.data = NULL;
296 }
297 
298 /**
299  * msi_setup_device_data - Setup MSI device data
300  * @dev:	Device for which MSI device data should be set up
301  *
302  * Return: 0 on success, appropriate error code otherwise
303  *
304  * This can be called more than once for @dev. If the MSI device data is
305  * already allocated the call succeeds. The allocated memory is
306  * automatically released when the device is destroyed.
307  */
msi_setup_device_data(struct device * dev)308 int msi_setup_device_data(struct device *dev)
309 {
310 	struct msi_device_data *md;
311 	int ret, i;
312 
313 	if (dev->msi.data)
314 		return 0;
315 
316 	md = devres_alloc(msi_device_data_release, sizeof(*md), GFP_KERNEL);
317 	if (!md)
318 		return -ENOMEM;
319 
320 	ret = msi_sysfs_create_group(dev);
321 	if (ret) {
322 		devres_free(md);
323 		return ret;
324 	}
325 
326 	for (i = 0; i < MSI_MAX_DEVICE_IRQDOMAINS; i++)
327 		xa_init_flags(&md->__domains[i].store, XA_FLAGS_ALLOC);
328 
329 	/*
330 	 * If @dev::msi::domain is set and is a global MSI domain, copy the
331 	 * pointer into the domain array so all code can operate on domain
332 	 * ids. The NULL pointer check is required to keep the legacy
333 	 * architecture specific PCI/MSI support working.
334 	 */
335 	if (dev->msi.domain && !irq_domain_is_msi_parent(dev->msi.domain))
336 		md->__domains[MSI_DEFAULT_DOMAIN].domain = dev->msi.domain;
337 
338 	mutex_init(&md->mutex);
339 	dev->msi.data = md;
340 	devres_add(dev, md);
341 	return 0;
342 }
343 
344 /**
345  * msi_lock_descs - Lock the MSI descriptor storage of a device
346  * @dev:	Device to operate on
347  */
msi_lock_descs(struct device * dev)348 void msi_lock_descs(struct device *dev)
349 {
350 	mutex_lock(&dev->msi.data->mutex);
351 }
352 EXPORT_SYMBOL_GPL(msi_lock_descs);
353 
354 /**
355  * msi_unlock_descs - Unlock the MSI descriptor storage of a device
356  * @dev:	Device to operate on
357  */
msi_unlock_descs(struct device * dev)358 void msi_unlock_descs(struct device *dev)
359 {
360 	/* Invalidate the index which was cached by the iterator */
361 	dev->msi.data->__iter_idx = MSI_XA_MAX_INDEX;
362 	mutex_unlock(&dev->msi.data->mutex);
363 }
364 EXPORT_SYMBOL_GPL(msi_unlock_descs);
365 
msi_find_desc(struct msi_device_data * md,unsigned int domid,enum msi_desc_filter filter)366 static struct msi_desc *msi_find_desc(struct msi_device_data *md, unsigned int domid,
367 				      enum msi_desc_filter filter)
368 {
369 	struct xarray *xa = &md->__domains[domid].store;
370 	struct msi_desc *desc;
371 
372 	xa_for_each_start(xa, md->__iter_idx, desc, md->__iter_idx) {
373 		if (msi_desc_match(desc, filter))
374 			return desc;
375 	}
376 	md->__iter_idx = MSI_XA_MAX_INDEX;
377 	return NULL;
378 }
379 
380 /**
381  * msi_domain_first_desc - Get the first MSI descriptor of an irqdomain associated to a device
382  * @dev:	Device to operate on
383  * @domid:	The id of the interrupt domain which should be walked.
384  * @filter:	Descriptor state filter
385  *
386  * Must be called with the MSI descriptor mutex held, i.e. msi_lock_descs()
387  * must be invoked before the call.
388  *
389  * Return: Pointer to the first MSI descriptor matching the search
390  *	   criteria, NULL if none found.
391  */
msi_domain_first_desc(struct device * dev,unsigned int domid,enum msi_desc_filter filter)392 struct msi_desc *msi_domain_first_desc(struct device *dev, unsigned int domid,
393 				       enum msi_desc_filter filter)
394 {
395 	struct msi_device_data *md = dev->msi.data;
396 
397 	if (WARN_ON_ONCE(!md || domid >= MSI_MAX_DEVICE_IRQDOMAINS))
398 		return NULL;
399 
400 	lockdep_assert_held(&md->mutex);
401 
402 	md->__iter_idx = 0;
403 	return msi_find_desc(md, domid, filter);
404 }
405 EXPORT_SYMBOL_GPL(msi_domain_first_desc);
406 
407 /**
408  * msi_next_desc - Get the next MSI descriptor of a device
409  * @dev:	Device to operate on
410  * @domid:	The id of the interrupt domain which should be walked.
411  * @filter:	Descriptor state filter
412  *
413  * The first invocation of msi_next_desc() has to be preceeded by a
414  * successful invocation of __msi_first_desc(). Consecutive invocations are
415  * only valid if the previous one was successful. All these operations have
416  * to be done within the same MSI mutex held region.
417  *
418  * Return: Pointer to the next MSI descriptor matching the search
419  *	   criteria, NULL if none found.
420  */
msi_next_desc(struct device * dev,unsigned int domid,enum msi_desc_filter filter)421 struct msi_desc *msi_next_desc(struct device *dev, unsigned int domid,
422 			       enum msi_desc_filter filter)
423 {
424 	struct msi_device_data *md = dev->msi.data;
425 
426 	if (WARN_ON_ONCE(!md || domid >= MSI_MAX_DEVICE_IRQDOMAINS))
427 		return NULL;
428 
429 	lockdep_assert_held(&md->mutex);
430 
431 	if (md->__iter_idx >= (unsigned long)MSI_MAX_INDEX)
432 		return NULL;
433 
434 	md->__iter_idx++;
435 	return msi_find_desc(md, domid, filter);
436 }
437 EXPORT_SYMBOL_GPL(msi_next_desc);
438 
439 /**
440  * msi_domain_get_virq - Lookup the Linux interrupt number for a MSI index on a interrupt domain
441  * @dev:	Device to operate on
442  * @domid:	Domain ID of the interrupt domain associated to the device
443  * @index:	MSI interrupt index to look for (0-based)
444  *
445  * Return: The Linux interrupt number on success (> 0), 0 if not found
446  */
msi_domain_get_virq(struct device * dev,unsigned int domid,unsigned int index)447 unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index)
448 {
449 	struct msi_desc *desc;
450 	unsigned int ret = 0;
451 	bool pcimsi = false;
452 	struct xarray *xa;
453 
454 	if (!dev->msi.data)
455 		return 0;
456 
457 	if (WARN_ON_ONCE(index > MSI_MAX_INDEX || domid >= MSI_MAX_DEVICE_IRQDOMAINS))
458 		return 0;
459 
460 	/* This check is only valid for the PCI default MSI domain */
461 	if (dev_is_pci(dev) && domid == MSI_DEFAULT_DOMAIN)
462 		pcimsi = to_pci_dev(dev)->msi_enabled;
463 
464 	msi_lock_descs(dev);
465 	xa = &dev->msi.data->__domains[domid].store;
466 	desc = xa_load(xa, pcimsi ? 0 : index);
467 	if (desc && desc->irq) {
468 		/*
469 		 * PCI-MSI has only one descriptor for multiple interrupts.
470 		 * PCI-MSIX and platform MSI use a descriptor per
471 		 * interrupt.
472 		 */
473 		if (pcimsi) {
474 			if (index < desc->nvec_used)
475 				ret = desc->irq + index;
476 		} else {
477 			ret = desc->irq;
478 		}
479 	}
480 
481 	msi_unlock_descs(dev);
482 	return ret;
483 }
484 EXPORT_SYMBOL_GPL(msi_domain_get_virq);
485 
486 #ifdef CONFIG_SYSFS
487 static struct attribute *msi_dev_attrs[] = {
488 	NULL
489 };
490 
491 static const struct attribute_group msi_irqs_group = {
492 	.name	= "msi_irqs",
493 	.attrs	= msi_dev_attrs,
494 };
495 
msi_sysfs_create_group(struct device * dev)496 static inline int msi_sysfs_create_group(struct device *dev)
497 {
498 	return devm_device_add_group(dev, &msi_irqs_group);
499 }
500 
msi_mode_show(struct device * dev,struct device_attribute * attr,char * buf)501 static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
502 			     char *buf)
503 {
504 	/* MSI vs. MSIX is per device not per interrupt */
505 	bool is_msix = dev_is_pci(dev) ? to_pci_dev(dev)->msix_enabled : false;
506 
507 	return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi");
508 }
509 
msi_sysfs_remove_desc(struct device * dev,struct msi_desc * desc)510 static void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc)
511 {
512 	struct device_attribute *attrs = desc->sysfs_attrs;
513 	int i;
514 
515 	if (!attrs)
516 		return;
517 
518 	desc->sysfs_attrs = NULL;
519 	for (i = 0; i < desc->nvec_used; i++) {
520 		if (attrs[i].show)
521 			sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
522 		kfree(attrs[i].attr.name);
523 	}
524 	kfree(attrs);
525 }
526 
msi_sysfs_populate_desc(struct device * dev,struct msi_desc * desc)527 static int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc)
528 {
529 	struct device_attribute *attrs;
530 	int ret, i;
531 
532 	attrs = kcalloc(desc->nvec_used, sizeof(*attrs), GFP_KERNEL);
533 	if (!attrs)
534 		return -ENOMEM;
535 
536 	desc->sysfs_attrs = attrs;
537 	for (i = 0; i < desc->nvec_used; i++) {
538 		sysfs_attr_init(&attrs[i].attr);
539 		attrs[i].attr.name = kasprintf(GFP_KERNEL, "%d", desc->irq + i);
540 		if (!attrs[i].attr.name) {
541 			ret = -ENOMEM;
542 			goto fail;
543 		}
544 
545 		attrs[i].attr.mode = 0444;
546 		attrs[i].show = msi_mode_show;
547 
548 		ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
549 		if (ret) {
550 			attrs[i].show = NULL;
551 			goto fail;
552 		}
553 	}
554 	return 0;
555 
556 fail:
557 	msi_sysfs_remove_desc(dev, desc);
558 	return ret;
559 }
560 
561 #if defined(CONFIG_PCI_MSI_ARCH_FALLBACKS) || defined(CONFIG_PCI_XEN)
562 /**
563  * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
564  * @dev:	The device (PCI, platform etc) which will get sysfs entries
565  */
msi_device_populate_sysfs(struct device * dev)566 int msi_device_populate_sysfs(struct device *dev)
567 {
568 	struct msi_desc *desc;
569 	int ret;
570 
571 	msi_for_each_desc(desc, dev, MSI_DESC_ASSOCIATED) {
572 		if (desc->sysfs_attrs)
573 			continue;
574 		ret = msi_sysfs_populate_desc(dev, desc);
575 		if (ret)
576 			return ret;
577 	}
578 	return 0;
579 }
580 
581 /**
582  * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
583  * @dev:		The device (PCI, platform etc) for which to remove
584  *			sysfs entries
585  */
msi_device_destroy_sysfs(struct device * dev)586 void msi_device_destroy_sysfs(struct device *dev)
587 {
588 	struct msi_desc *desc;
589 
590 	msi_for_each_desc(desc, dev, MSI_DESC_ALL)
591 		msi_sysfs_remove_desc(dev, desc);
592 }
593 #endif /* CONFIG_PCI_MSI_ARCH_FALLBACK || CONFIG_PCI_XEN */
594 #else /* CONFIG_SYSFS */
msi_sysfs_create_group(struct device * dev)595 static inline int msi_sysfs_create_group(struct device *dev) { return 0; }
msi_sysfs_populate_desc(struct device * dev,struct msi_desc * desc)596 static inline int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc) { return 0; }
msi_sysfs_remove_desc(struct device * dev,struct msi_desc * desc)597 static inline void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc) { }
598 #endif /* !CONFIG_SYSFS */
599 
msi_get_device_domain(struct device * dev,unsigned int domid)600 static struct irq_domain *msi_get_device_domain(struct device *dev, unsigned int domid)
601 {
602 	struct irq_domain *domain;
603 
604 	lockdep_assert_held(&dev->msi.data->mutex);
605 
606 	if (WARN_ON_ONCE(domid >= MSI_MAX_DEVICE_IRQDOMAINS))
607 		return NULL;
608 
609 	domain = dev->msi.data->__domains[domid].domain;
610 	if (!domain)
611 		return NULL;
612 
613 	if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain)))
614 		return NULL;
615 
616 	return domain;
617 }
618 
msi_domain_get_hwsize(struct device * dev,unsigned int domid)619 static unsigned int msi_domain_get_hwsize(struct device *dev, unsigned int domid)
620 {
621 	struct msi_domain_info *info;
622 	struct irq_domain *domain;
623 
624 	domain = msi_get_device_domain(dev, domid);
625 	if (domain) {
626 		info = domain->host_data;
627 		return info->hwsize;
628 	}
629 	/* No domain, default to MSI_XA_DOMAIN_SIZE */
630 	return MSI_XA_DOMAIN_SIZE;
631 }
632 
irq_chip_write_msi_msg(struct irq_data * data,struct msi_msg * msg)633 static inline void irq_chip_write_msi_msg(struct irq_data *data,
634 					  struct msi_msg *msg)
635 {
636 	data->chip->irq_write_msi_msg(data, msg);
637 }
638 
msi_check_level(struct irq_domain * domain,struct msi_msg * msg)639 static void msi_check_level(struct irq_domain *domain, struct msi_msg *msg)
640 {
641 	struct msi_domain_info *info = domain->host_data;
642 
643 	/*
644 	 * If the MSI provider has messed with the second message and
645 	 * not advertized that it is level-capable, signal the breakage.
646 	 */
647 	WARN_ON(!((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
648 		  (info->chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)) &&
649 		(msg[1].address_lo || msg[1].address_hi || msg[1].data));
650 }
651 
652 /**
653  * msi_domain_set_affinity - Generic affinity setter function for MSI domains
654  * @irq_data:	The irq data associated to the interrupt
655  * @mask:	The affinity mask to set
656  * @force:	Flag to enforce setting (disable online checks)
657  *
658  * Intended to be used by MSI interrupt controllers which are
659  * implemented with hierarchical domains.
660  *
661  * Return: IRQ_SET_MASK_* result code
662  */
msi_domain_set_affinity(struct irq_data * irq_data,const struct cpumask * mask,bool force)663 int msi_domain_set_affinity(struct irq_data *irq_data,
664 			    const struct cpumask *mask, bool force)
665 {
666 	struct irq_data *parent = irq_data->parent_data;
667 	struct msi_msg msg[2] = { [1] = { }, };
668 	int ret;
669 
670 	ret = parent->chip->irq_set_affinity(parent, mask, force);
671 	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
672 		BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
673 		msi_check_level(irq_data->domain, msg);
674 		irq_chip_write_msi_msg(irq_data, msg);
675 	}
676 
677 	return ret;
678 }
679 
msi_domain_activate(struct irq_domain * domain,struct irq_data * irq_data,bool early)680 static int msi_domain_activate(struct irq_domain *domain,
681 			       struct irq_data *irq_data, bool early)
682 {
683 	struct msi_msg msg[2] = { [1] = { }, };
684 
685 	BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
686 	msi_check_level(irq_data->domain, msg);
687 	irq_chip_write_msi_msg(irq_data, msg);
688 	return 0;
689 }
690 
msi_domain_deactivate(struct irq_domain * domain,struct irq_data * irq_data)691 static void msi_domain_deactivate(struct irq_domain *domain,
692 				  struct irq_data *irq_data)
693 {
694 	struct msi_msg msg[2];
695 
696 	memset(msg, 0, sizeof(msg));
697 	irq_chip_write_msi_msg(irq_data, msg);
698 }
699 
msi_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)700 static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
701 			    unsigned int nr_irqs, void *arg)
702 {
703 	struct msi_domain_info *info = domain->host_data;
704 	struct msi_domain_ops *ops = info->ops;
705 	irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
706 	int i, ret;
707 
708 	if (irq_find_mapping(domain, hwirq) > 0)
709 		return -EEXIST;
710 
711 	if (domain->parent) {
712 		ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
713 		if (ret < 0)
714 			return ret;
715 	}
716 
717 	for (i = 0; i < nr_irqs; i++) {
718 		ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
719 		if (ret < 0) {
720 			if (ops->msi_free) {
721 				for (i--; i >= 0; i--)
722 					ops->msi_free(domain, info, virq + i);
723 			}
724 			irq_domain_free_irqs_top(domain, virq, nr_irqs);
725 			return ret;
726 		}
727 	}
728 
729 	return 0;
730 }
731 
msi_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)732 static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
733 			    unsigned int nr_irqs)
734 {
735 	struct msi_domain_info *info = domain->host_data;
736 	int i;
737 
738 	if (info->ops->msi_free) {
739 		for (i = 0; i < nr_irqs; i++)
740 			info->ops->msi_free(domain, info, virq + i);
741 	}
742 	irq_domain_free_irqs_top(domain, virq, nr_irqs);
743 }
744 
msi_domain_translate(struct irq_domain * domain,struct irq_fwspec * fwspec,irq_hw_number_t * hwirq,unsigned int * type)745 static int msi_domain_translate(struct irq_domain *domain, struct irq_fwspec *fwspec,
746 				irq_hw_number_t *hwirq, unsigned int *type)
747 {
748 	struct msi_domain_info *info = domain->host_data;
749 
750 	/*
751 	 * This will catch allocations through the regular irqdomain path except
752 	 * for MSI domains which really support this, e.g. MBIGEN.
753 	 */
754 	if (!info->ops->msi_translate)
755 		return -ENOTSUPP;
756 	return info->ops->msi_translate(domain, fwspec, hwirq, type);
757 }
758 
759 static const struct irq_domain_ops msi_domain_ops = {
760 	.alloc		= msi_domain_alloc,
761 	.free		= msi_domain_free,
762 	.activate	= msi_domain_activate,
763 	.deactivate	= msi_domain_deactivate,
764 	.translate	= msi_domain_translate,
765 };
766 
msi_domain_ops_get_hwirq(struct msi_domain_info * info,msi_alloc_info_t * arg)767 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
768 						msi_alloc_info_t *arg)
769 {
770 	return arg->hwirq;
771 }
772 
msi_domain_ops_prepare(struct irq_domain * domain,struct device * dev,int nvec,msi_alloc_info_t * arg)773 static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
774 				  int nvec, msi_alloc_info_t *arg)
775 {
776 	memset(arg, 0, sizeof(*arg));
777 	return 0;
778 }
779 
msi_domain_ops_set_desc(msi_alloc_info_t * arg,struct msi_desc * desc)780 static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
781 				    struct msi_desc *desc)
782 {
783 	arg->desc = desc;
784 }
785 
msi_domain_ops_init(struct irq_domain * domain,struct msi_domain_info * info,unsigned int virq,irq_hw_number_t hwirq,msi_alloc_info_t * arg)786 static int msi_domain_ops_init(struct irq_domain *domain,
787 			       struct msi_domain_info *info,
788 			       unsigned int virq, irq_hw_number_t hwirq,
789 			       msi_alloc_info_t *arg)
790 {
791 	irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
792 				      info->chip_data);
793 	if (info->handler && info->handler_name) {
794 		__irq_set_handler(virq, info->handler, 0, info->handler_name);
795 		if (info->handler_data)
796 			irq_set_handler_data(virq, info->handler_data);
797 	}
798 	return 0;
799 }
800 
801 static struct msi_domain_ops msi_domain_ops_default = {
802 	.get_hwirq		= msi_domain_ops_get_hwirq,
803 	.msi_init		= msi_domain_ops_init,
804 	.msi_prepare		= msi_domain_ops_prepare,
805 	.set_desc		= msi_domain_ops_set_desc,
806 };
807 
msi_domain_update_dom_ops(struct msi_domain_info * info)808 static void msi_domain_update_dom_ops(struct msi_domain_info *info)
809 {
810 	struct msi_domain_ops *ops = info->ops;
811 
812 	if (ops == NULL) {
813 		info->ops = &msi_domain_ops_default;
814 		return;
815 	}
816 
817 	if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
818 		return;
819 
820 	if (ops->get_hwirq == NULL)
821 		ops->get_hwirq = msi_domain_ops_default.get_hwirq;
822 	if (ops->msi_init == NULL)
823 		ops->msi_init = msi_domain_ops_default.msi_init;
824 	if (ops->msi_prepare == NULL)
825 		ops->msi_prepare = msi_domain_ops_default.msi_prepare;
826 	if (ops->set_desc == NULL)
827 		ops->set_desc = msi_domain_ops_default.set_desc;
828 }
829 
msi_domain_update_chip_ops(struct msi_domain_info * info)830 static void msi_domain_update_chip_ops(struct msi_domain_info *info)
831 {
832 	struct irq_chip *chip = info->chip;
833 
834 	BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
835 	if (!chip->irq_set_affinity && !(info->flags & MSI_FLAG_NO_AFFINITY))
836 		chip->irq_set_affinity = msi_domain_set_affinity;
837 }
838 
__msi_create_irq_domain(struct fwnode_handle * fwnode,struct msi_domain_info * info,unsigned int flags,struct irq_domain * parent)839 static struct irq_domain *__msi_create_irq_domain(struct fwnode_handle *fwnode,
840 						  struct msi_domain_info *info,
841 						  unsigned int flags,
842 						  struct irq_domain *parent)
843 {
844 	struct irq_domain *domain;
845 
846 	if (info->hwsize > MSI_XA_DOMAIN_SIZE)
847 		return NULL;
848 
849 	/*
850 	 * Hardware size 0 is valid for backwards compatibility and for
851 	 * domains which are not backed by a hardware table. Grant the
852 	 * maximum index space.
853 	 */
854 	if (!info->hwsize)
855 		info->hwsize = MSI_XA_DOMAIN_SIZE;
856 
857 	msi_domain_update_dom_ops(info);
858 	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
859 		msi_domain_update_chip_ops(info);
860 
861 	domain = irq_domain_create_hierarchy(parent, flags | IRQ_DOMAIN_FLAG_MSI, 0,
862 					     fwnode, &msi_domain_ops, info);
863 
864 	if (domain) {
865 		irq_domain_update_bus_token(domain, info->bus_token);
866 		if (info->flags & MSI_FLAG_PARENT_PM_DEV)
867 			domain->pm_dev = parent->pm_dev;
868 	}
869 
870 	return domain;
871 }
872 
873 /**
874  * msi_create_irq_domain - Create an MSI interrupt domain
875  * @fwnode:	Optional fwnode of the interrupt controller
876  * @info:	MSI domain info
877  * @parent:	Parent irq domain
878  *
879  * Return: pointer to the created &struct irq_domain or %NULL on failure
880  */
msi_create_irq_domain(struct fwnode_handle * fwnode,struct msi_domain_info * info,struct irq_domain * parent)881 struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
882 					 struct msi_domain_info *info,
883 					 struct irq_domain *parent)
884 {
885 	return __msi_create_irq_domain(fwnode, info, 0, parent);
886 }
887 
888 /**
889  * msi_parent_init_dev_msi_info - Delegate initialization of device MSI info down
890  *				  in the domain hierarchy
891  * @dev:		The device for which the domain should be created
892  * @domain:		The domain in the hierarchy this op is being called on
893  * @msi_parent_domain:	The IRQ_DOMAIN_FLAG_MSI_PARENT domain for the child to
894  *			be created
895  * @msi_child_info:	The MSI domain info of the IRQ_DOMAIN_FLAG_MSI_DEVICE
896  *			domain to be created
897  *
898  * Return: true on success, false otherwise
899  *
900  * This is the most complex problem of per device MSI domains and the
901  * underlying interrupt domain hierarchy:
902  *
903  * The device domain to be initialized requests the broadest feature set
904  * possible and the underlying domain hierarchy puts restrictions on it.
905  *
906  * That's trivial for a simple parent->child relationship, but it gets
907  * interesting with an intermediate domain: root->parent->child.  The
908  * intermediate 'parent' can expand the capabilities which the 'root'
909  * domain is providing. So that creates a classic hen and egg problem:
910  * Which entity is doing the restrictions/expansions?
911  *
912  * One solution is to let the root domain handle the initialization that's
913  * why there is the @domain and the @msi_parent_domain pointer.
914  */
msi_parent_init_dev_msi_info(struct device * dev,struct irq_domain * domain,struct irq_domain * msi_parent_domain,struct msi_domain_info * msi_child_info)915 bool msi_parent_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
916 				  struct irq_domain *msi_parent_domain,
917 				  struct msi_domain_info *msi_child_info)
918 {
919 	struct irq_domain *parent = domain->parent;
920 
921 	if (WARN_ON_ONCE(!parent || !parent->msi_parent_ops ||
922 			 !parent->msi_parent_ops->init_dev_msi_info))
923 		return false;
924 
925 	return parent->msi_parent_ops->init_dev_msi_info(dev, parent, msi_parent_domain,
926 							 msi_child_info);
927 }
928 
929 /**
930  * msi_create_device_irq_domain - Create a device MSI interrupt domain
931  * @dev:		Pointer to the device
932  * @domid:		Domain id
933  * @template:		MSI domain info bundle used as template
934  * @hwsize:		Maximum number of MSI table entries (0 if unknown or unlimited)
935  * @domain_data:	Optional pointer to domain specific data which is set in
936  *			msi_domain_info::data
937  * @chip_data:		Optional pointer to chip specific data which is set in
938  *			msi_domain_info::chip_data
939  *
940  * Return: True on success, false otherwise
941  *
942  * There is no firmware node required for this interface because the per
943  * device domains are software constructs which are actually closer to the
944  * hardware reality than any firmware can describe them.
945  *
946  * The domain name and the irq chip name for a MSI device domain are
947  * composed by: "$(PREFIX)$(CHIPNAME)-$(DEVNAME)"
948  *
949  * $PREFIX:   Optional prefix provided by the underlying MSI parent domain
950  *	      via msi_parent_ops::prefix. If that pointer is NULL the prefix
951  *	      is empty.
952  * $CHIPNAME: The name of the irq_chip in @template
953  * $DEVNAME:  The name of the device
954  *
955  * This results in understandable chip names and hardware interrupt numbers
956  * in e.g. /proc/interrupts
957  *
958  * PCI-MSI-0000:00:1c.0     0-edge  Parent domain has no prefix
959  * IR-PCI-MSI-0000:00:1c.4  0-edge  Same with interrupt remapping prefix 'IR-'
960  *
961  * IR-PCI-MSIX-0000:3d:00.0 0-edge  Hardware interrupt numbers reflect
962  * IR-PCI-MSIX-0000:3d:00.0 1-edge  the real MSI-X index on that device
963  * IR-PCI-MSIX-0000:3d:00.0 2-edge
964  *
965  * On IMS domains the hardware interrupt number is either a table entry
966  * index or a purely software managed index but it is guaranteed to be
967  * unique.
968  *
969  * The domain pointer is stored in @dev::msi::data::__irqdomains[]. All
970  * subsequent operations on the domain depend on the domain id.
971  *
972  * The domain is automatically freed when the device is removed via devres
973  * in the context of @dev::msi::data freeing, but it can also be
974  * independently removed via @msi_remove_device_irq_domain().
975  */
msi_create_device_irq_domain(struct device * dev,unsigned int domid,const struct msi_domain_template * template,unsigned int hwsize,void * domain_data,void * chip_data)976 bool msi_create_device_irq_domain(struct device *dev, unsigned int domid,
977 				  const struct msi_domain_template *template,
978 				  unsigned int hwsize, void *domain_data,
979 				  void *chip_data)
980 {
981 	struct irq_domain *domain, *parent = dev->msi.domain;
982 	struct fwnode_handle *fwnode, *fwnalloced = NULL;
983 	struct msi_domain_template *bundle;
984 	const struct msi_parent_ops *pops;
985 
986 	if (!irq_domain_is_msi_parent(parent))
987 		return false;
988 
989 	if (domid >= MSI_MAX_DEVICE_IRQDOMAINS)
990 		return false;
991 
992 	bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);
993 	if (!bundle)
994 		return false;
995 
996 	bundle->info.hwsize = hwsize;
997 	bundle->info.chip = &bundle->chip;
998 	bundle->info.ops = &bundle->ops;
999 	bundle->info.data = domain_data;
1000 	bundle->info.chip_data = chip_data;
1001 
1002 	pops = parent->msi_parent_ops;
1003 	snprintf(bundle->name, sizeof(bundle->name), "%s%s-%s",
1004 		 pops->prefix ? : "", bundle->chip.name, dev_name(dev));
1005 	bundle->chip.name = bundle->name;
1006 
1007 	/*
1008 	 * Using the device firmware node is required for wire to MSI
1009 	 * device domains so that the existing firmware results in a domain
1010 	 * match.
1011 	 * All other device domains like PCI/MSI use the named firmware
1012 	 * node as they are not guaranteed to have a fwnode. They are never
1013 	 * looked up and always handled in the context of the device.
1014 	 */
1015 	if (bundle->info.flags & MSI_FLAG_USE_DEV_FWNODE)
1016 		fwnode = dev->fwnode;
1017 	else
1018 		fwnode = fwnalloced = irq_domain_alloc_named_fwnode(bundle->name);
1019 
1020 	if (!fwnode)
1021 		goto free_bundle;
1022 
1023 	if (msi_setup_device_data(dev))
1024 		goto free_fwnode;
1025 
1026 	msi_lock_descs(dev);
1027 
1028 	if (WARN_ON_ONCE(msi_get_device_domain(dev, domid)))
1029 		goto fail;
1030 
1031 	if (!pops->init_dev_msi_info(dev, parent, parent, &bundle->info))
1032 		goto fail;
1033 
1034 	domain = __msi_create_irq_domain(fwnode, &bundle->info, IRQ_DOMAIN_FLAG_MSI_DEVICE, parent);
1035 	if (!domain)
1036 		goto fail;
1037 
1038 	domain->dev = dev;
1039 	dev->msi.data->__domains[domid].domain = domain;
1040 	msi_unlock_descs(dev);
1041 	return true;
1042 
1043 fail:
1044 	msi_unlock_descs(dev);
1045 free_fwnode:
1046 	irq_domain_free_fwnode(fwnalloced);
1047 free_bundle:
1048 	kfree(bundle);
1049 	return false;
1050 }
1051 
1052 /**
1053  * msi_remove_device_irq_domain - Free a device MSI interrupt domain
1054  * @dev:	Pointer to the device
1055  * @domid:	Domain id
1056  */
msi_remove_device_irq_domain(struct device * dev,unsigned int domid)1057 void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
1058 {
1059 	struct fwnode_handle *fwnode = NULL;
1060 	struct msi_domain_info *info;
1061 	struct irq_domain *domain;
1062 
1063 	msi_lock_descs(dev);
1064 
1065 	domain = msi_get_device_domain(dev, domid);
1066 
1067 	if (!domain || !irq_domain_is_msi_device(domain))
1068 		goto unlock;
1069 
1070 	dev->msi.data->__domains[domid].domain = NULL;
1071 	info = domain->host_data;
1072 	if (irq_domain_is_msi_device(domain))
1073 		fwnode = domain->fwnode;
1074 	irq_domain_remove(domain);
1075 	irq_domain_free_fwnode(fwnode);
1076 	kfree(container_of(info, struct msi_domain_template, info));
1077 
1078 unlock:
1079 	msi_unlock_descs(dev);
1080 }
1081 
1082 /**
1083  * msi_match_device_irq_domain - Match a device irq domain against a bus token
1084  * @dev:	Pointer to the device
1085  * @domid:	Domain id
1086  * @bus_token:	Bus token to match against the domain bus token
1087  *
1088  * Return: True if device domain exists and bus tokens match.
1089  */
msi_match_device_irq_domain(struct device * dev,unsigned int domid,enum irq_domain_bus_token bus_token)1090 bool msi_match_device_irq_domain(struct device *dev, unsigned int domid,
1091 				 enum irq_domain_bus_token bus_token)
1092 {
1093 	struct msi_domain_info *info;
1094 	struct irq_domain *domain;
1095 	bool ret = false;
1096 
1097 	msi_lock_descs(dev);
1098 	domain = msi_get_device_domain(dev, domid);
1099 	if (domain && irq_domain_is_msi_device(domain)) {
1100 		info = domain->host_data;
1101 		ret = info->bus_token == bus_token;
1102 	}
1103 	msi_unlock_descs(dev);
1104 	return ret;
1105 }
1106 
msi_domain_prepare_irqs(struct irq_domain * domain,struct device * dev,int nvec,msi_alloc_info_t * arg)1107 static int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
1108 				   int nvec, msi_alloc_info_t *arg)
1109 {
1110 	struct msi_domain_info *info = domain->host_data;
1111 	struct msi_domain_ops *ops = info->ops;
1112 
1113 	return ops->msi_prepare(domain, dev, nvec, arg);
1114 }
1115 
1116 /*
1117  * Carefully check whether the device can use reservation mode. If
1118  * reservation mode is enabled then the early activation will assign a
1119  * dummy vector to the device. If the PCI/MSI device does not support
1120  * masking of the entry then this can result in spurious interrupts when
1121  * the device driver is not absolutely careful. But even then a malfunction
1122  * of the hardware could result in a spurious interrupt on the dummy vector
1123  * and render the device unusable. If the entry can be masked then the core
1124  * logic will prevent the spurious interrupt and reservation mode can be
1125  * used. For now reservation mode is restricted to PCI/MSI.
1126  */
msi_check_reservation_mode(struct irq_domain * domain,struct msi_domain_info * info,struct device * dev)1127 static bool msi_check_reservation_mode(struct irq_domain *domain,
1128 				       struct msi_domain_info *info,
1129 				       struct device *dev)
1130 {
1131 	struct msi_desc *desc;
1132 
1133 	switch(domain->bus_token) {
1134 	case DOMAIN_BUS_PCI_MSI:
1135 	case DOMAIN_BUS_PCI_DEVICE_MSI:
1136 	case DOMAIN_BUS_PCI_DEVICE_MSIX:
1137 	case DOMAIN_BUS_VMD_MSI:
1138 		break;
1139 	default:
1140 		return false;
1141 	}
1142 
1143 	if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
1144 		return false;
1145 
1146 	if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask)
1147 		return false;
1148 
1149 	/*
1150 	 * Checking the first MSI descriptor is sufficient. MSIX supports
1151 	 * masking and MSI does so when the can_mask attribute is set.
1152 	 */
1153 	desc = msi_first_desc(dev, MSI_DESC_ALL);
1154 	return desc->pci.msi_attrib.is_msix || desc->pci.msi_attrib.can_mask;
1155 }
1156 
msi_handle_pci_fail(struct irq_domain * domain,struct msi_desc * desc,int allocated)1157 static int msi_handle_pci_fail(struct irq_domain *domain, struct msi_desc *desc,
1158 			       int allocated)
1159 {
1160 	switch(domain->bus_token) {
1161 	case DOMAIN_BUS_PCI_MSI:
1162 	case DOMAIN_BUS_PCI_DEVICE_MSI:
1163 	case DOMAIN_BUS_PCI_DEVICE_MSIX:
1164 	case DOMAIN_BUS_VMD_MSI:
1165 		if (IS_ENABLED(CONFIG_PCI_MSI))
1166 			break;
1167 		fallthrough;
1168 	default:
1169 		return -ENOSPC;
1170 	}
1171 
1172 	/* Let a failed PCI multi MSI allocation retry */
1173 	if (desc->nvec_used > 1)
1174 		return 1;
1175 
1176 	/* If there was a successful allocation let the caller know */
1177 	return allocated ? allocated : -ENOSPC;
1178 }
1179 
1180 #define VIRQ_CAN_RESERVE	0x01
1181 #define VIRQ_ACTIVATE		0x02
1182 
msi_init_virq(struct irq_domain * domain,int virq,unsigned int vflags)1183 static int msi_init_virq(struct irq_domain *domain, int virq, unsigned int vflags)
1184 {
1185 	struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
1186 	int ret;
1187 
1188 	if (!(vflags & VIRQ_CAN_RESERVE)) {
1189 		irqd_clr_can_reserve(irqd);
1190 
1191 		/*
1192 		 * If the interrupt is managed but no CPU is available to
1193 		 * service it, shut it down until better times. Note that
1194 		 * we only do this on the !RESERVE path as x86 (the only
1195 		 * architecture using this flag) deals with this in a
1196 		 * different way by using a catch-all vector.
1197 		 */
1198 		if ((vflags & VIRQ_ACTIVATE) &&
1199 		    irqd_affinity_is_managed(irqd) &&
1200 		    !cpumask_intersects(irq_data_get_affinity_mask(irqd),
1201 					cpu_online_mask)) {
1202 			    irqd_set_managed_shutdown(irqd);
1203 			    return 0;
1204 		    }
1205 	}
1206 
1207 	if (!(vflags & VIRQ_ACTIVATE))
1208 		return 0;
1209 
1210 	ret = irq_domain_activate_irq(irqd, vflags & VIRQ_CAN_RESERVE);
1211 	if (ret)
1212 		return ret;
1213 	/*
1214 	 * If the interrupt uses reservation mode, clear the activated bit
1215 	 * so request_irq() will assign the final vector.
1216 	 */
1217 	if (vflags & VIRQ_CAN_RESERVE)
1218 		irqd_clr_activated(irqd);
1219 	return 0;
1220 }
1221 
__msi_domain_alloc_irqs(struct device * dev,struct irq_domain * domain,struct msi_ctrl * ctrl)1222 static int __msi_domain_alloc_irqs(struct device *dev, struct irq_domain *domain,
1223 				   struct msi_ctrl *ctrl)
1224 {
1225 	struct xarray *xa = &dev->msi.data->__domains[ctrl->domid].store;
1226 	struct msi_domain_info *info = domain->host_data;
1227 	struct msi_domain_ops *ops = info->ops;
1228 	unsigned int vflags = 0, allocated = 0;
1229 	msi_alloc_info_t arg = { };
1230 	struct msi_desc *desc;
1231 	unsigned long idx;
1232 	int i, ret, virq;
1233 
1234 	ret = msi_domain_prepare_irqs(domain, dev, ctrl->nirqs, &arg);
1235 	if (ret)
1236 		return ret;
1237 
1238 	/*
1239 	 * This flag is set by the PCI layer as we need to activate
1240 	 * the MSI entries before the PCI layer enables MSI in the
1241 	 * card. Otherwise the card latches a random msi message.
1242 	 */
1243 	if (info->flags & MSI_FLAG_ACTIVATE_EARLY)
1244 		vflags |= VIRQ_ACTIVATE;
1245 
1246 	/*
1247 	 * Interrupt can use a reserved vector and will not occupy
1248 	 * a real device vector until the interrupt is requested.
1249 	 */
1250 	if (msi_check_reservation_mode(domain, info, dev))
1251 		vflags |= VIRQ_CAN_RESERVE;
1252 
1253 	xa_for_each_range(xa, idx, desc, ctrl->first, ctrl->last) {
1254 		if (!msi_desc_match(desc, MSI_DESC_NOTASSOCIATED))
1255 			continue;
1256 
1257 		/* This should return -ECONFUSED... */
1258 		if (WARN_ON_ONCE(allocated >= ctrl->nirqs))
1259 			return -EINVAL;
1260 
1261 		if (ops->prepare_desc)
1262 			ops->prepare_desc(domain, &arg, desc);
1263 
1264 		ops->set_desc(&arg, desc);
1265 
1266 		virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
1267 					       dev_to_node(dev), &arg, false,
1268 					       desc->affinity);
1269 		if (virq < 0)
1270 			return msi_handle_pci_fail(domain, desc, allocated);
1271 
1272 		for (i = 0; i < desc->nvec_used; i++) {
1273 			irq_set_msi_desc_off(virq, i, desc);
1274 			irq_debugfs_copy_devname(virq + i, dev);
1275 			ret = msi_init_virq(domain, virq + i, vflags);
1276 			if (ret)
1277 				return ret;
1278 		}
1279 		if (info->flags & MSI_FLAG_DEV_SYSFS) {
1280 			ret = msi_sysfs_populate_desc(dev, desc);
1281 			if (ret)
1282 				return ret;
1283 		}
1284 		allocated++;
1285 	}
1286 	return 0;
1287 }
1288 
msi_domain_alloc_simple_msi_descs(struct device * dev,struct msi_domain_info * info,struct msi_ctrl * ctrl)1289 static int msi_domain_alloc_simple_msi_descs(struct device *dev,
1290 					     struct msi_domain_info *info,
1291 					     struct msi_ctrl *ctrl)
1292 {
1293 	if (!(info->flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS))
1294 		return 0;
1295 
1296 	return msi_domain_add_simple_msi_descs(dev, ctrl);
1297 }
1298 
__msi_domain_alloc_locked(struct device * dev,struct msi_ctrl * ctrl)1299 static int __msi_domain_alloc_locked(struct device *dev, struct msi_ctrl *ctrl)
1300 {
1301 	struct msi_domain_info *info;
1302 	struct msi_domain_ops *ops;
1303 	struct irq_domain *domain;
1304 	int ret;
1305 
1306 	if (!msi_ctrl_valid(dev, ctrl))
1307 		return -EINVAL;
1308 
1309 	domain = msi_get_device_domain(dev, ctrl->domid);
1310 	if (!domain)
1311 		return -ENODEV;
1312 
1313 	info = domain->host_data;
1314 
1315 	ret = msi_domain_alloc_simple_msi_descs(dev, info, ctrl);
1316 	if (ret)
1317 		return ret;
1318 
1319 	ops = info->ops;
1320 	if (ops->domain_alloc_irqs)
1321 		return ops->domain_alloc_irqs(domain, dev, ctrl->nirqs);
1322 
1323 	return __msi_domain_alloc_irqs(dev, domain, ctrl);
1324 }
1325 
msi_domain_alloc_locked(struct device * dev,struct msi_ctrl * ctrl)1326 static int msi_domain_alloc_locked(struct device *dev, struct msi_ctrl *ctrl)
1327 {
1328 	int ret = __msi_domain_alloc_locked(dev, ctrl);
1329 
1330 	if (ret)
1331 		msi_domain_free_locked(dev, ctrl);
1332 	return ret;
1333 }
1334 
1335 /**
1336  * msi_domain_alloc_irqs_range_locked - Allocate interrupts from a MSI interrupt domain
1337  * @dev:	Pointer to device struct of the device for which the interrupts
1338  *		are allocated
1339  * @domid:	Id of the interrupt domain to operate on
1340  * @first:	First index to allocate (inclusive)
1341  * @last:	Last index to allocate (inclusive)
1342  *
1343  * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
1344  * pair. Use this for MSI irqdomains which implement their own descriptor
1345  * allocation/free.
1346  *
1347  * Return: %0 on success or an error code.
1348  */
msi_domain_alloc_irqs_range_locked(struct device * dev,unsigned int domid,unsigned int first,unsigned int last)1349 int msi_domain_alloc_irqs_range_locked(struct device *dev, unsigned int domid,
1350 				       unsigned int first, unsigned int last)
1351 {
1352 	struct msi_ctrl ctrl = {
1353 		.domid	= domid,
1354 		.first	= first,
1355 		.last	= last,
1356 		.nirqs	= last + 1 - first,
1357 	};
1358 
1359 	return msi_domain_alloc_locked(dev, &ctrl);
1360 }
1361 
1362 /**
1363  * msi_domain_alloc_irqs_range - Allocate interrupts from a MSI interrupt domain
1364  * @dev:	Pointer to device struct of the device for which the interrupts
1365  *		are allocated
1366  * @domid:	Id of the interrupt domain to operate on
1367  * @first:	First index to allocate (inclusive)
1368  * @last:	Last index to allocate (inclusive)
1369  *
1370  * Return: %0 on success or an error code.
1371  */
msi_domain_alloc_irqs_range(struct device * dev,unsigned int domid,unsigned int first,unsigned int last)1372 int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
1373 				unsigned int first, unsigned int last)
1374 {
1375 	int ret;
1376 
1377 	msi_lock_descs(dev);
1378 	ret = msi_domain_alloc_irqs_range_locked(dev, domid, first, last);
1379 	msi_unlock_descs(dev);
1380 	return ret;
1381 }
1382 EXPORT_SYMBOL_GPL(msi_domain_alloc_irqs_range);
1383 
1384 /**
1385  * msi_domain_alloc_irqs_all_locked - Allocate all interrupts from a MSI interrupt domain
1386  *
1387  * @dev:	Pointer to device struct of the device for which the interrupts
1388  *		are allocated
1389  * @domid:	Id of the interrupt domain to operate on
1390  * @nirqs:	The number of interrupts to allocate
1391  *
1392  * This function scans all MSI descriptors of the MSI domain and allocates interrupts
1393  * for all unassigned ones. That function is to be used for MSI domain usage where
1394  * the descriptor allocation is handled at the call site, e.g. PCI/MSI[X].
1395  *
1396  * Return: %0 on success or an error code.
1397  */
msi_domain_alloc_irqs_all_locked(struct device * dev,unsigned int domid,int nirqs)1398 int msi_domain_alloc_irqs_all_locked(struct device *dev, unsigned int domid, int nirqs)
1399 {
1400 	struct msi_ctrl ctrl = {
1401 		.domid	= domid,
1402 		.first	= 0,
1403 		.last	= msi_domain_get_hwsize(dev, domid) - 1,
1404 		.nirqs	= nirqs,
1405 	};
1406 
1407 	return msi_domain_alloc_locked(dev, &ctrl);
1408 }
1409 
__msi_domain_alloc_irq_at(struct device * dev,unsigned int domid,unsigned int index,const struct irq_affinity_desc * affdesc,union msi_instance_cookie * icookie)1410 static struct msi_map __msi_domain_alloc_irq_at(struct device *dev, unsigned int domid,
1411 						unsigned int index,
1412 						const struct irq_affinity_desc *affdesc,
1413 						union msi_instance_cookie *icookie)
1414 {
1415 	struct msi_ctrl ctrl = { .domid	= domid, .nirqs = 1, };
1416 	struct irq_domain *domain;
1417 	struct msi_map map = { };
1418 	struct msi_desc *desc;
1419 	int ret;
1420 
1421 	domain = msi_get_device_domain(dev, domid);
1422 	if (!domain) {
1423 		map.index = -ENODEV;
1424 		return map;
1425 	}
1426 
1427 	desc = msi_alloc_desc(dev, 1, affdesc);
1428 	if (!desc) {
1429 		map.index = -ENOMEM;
1430 		return map;
1431 	}
1432 
1433 	if (icookie)
1434 		desc->data.icookie = *icookie;
1435 
1436 	ret = msi_insert_desc(dev, desc, domid, index);
1437 	if (ret) {
1438 		map.index = ret;
1439 		return map;
1440 	}
1441 
1442 	ctrl.first = ctrl.last = desc->msi_index;
1443 
1444 	ret = __msi_domain_alloc_irqs(dev, domain, &ctrl);
1445 	if (ret) {
1446 		map.index = ret;
1447 		msi_domain_free_locked(dev, &ctrl);
1448 	} else {
1449 		map.index = desc->msi_index;
1450 		map.virq = desc->irq;
1451 	}
1452 	return map;
1453 }
1454 
1455 /**
1456  * msi_domain_alloc_irq_at - Allocate an interrupt from a MSI interrupt domain at
1457  *			     a given index - or at the next free index
1458  *
1459  * @dev:	Pointer to device struct of the device for which the interrupts
1460  *		are allocated
1461  * @domid:	Id of the interrupt domain to operate on
1462  * @index:	Index for allocation. If @index == %MSI_ANY_INDEX the allocation
1463  *		uses the next free index.
1464  * @affdesc:	Optional pointer to an interrupt affinity descriptor structure
1465  * @icookie:	Optional pointer to a domain specific per instance cookie. If
1466  *		non-NULL the content of the cookie is stored in msi_desc::data.
1467  *		Must be NULL for MSI-X allocations
1468  *
1469  * This requires a MSI interrupt domain which lets the core code manage the
1470  * MSI descriptors.
1471  *
1472  * Return: struct msi_map
1473  *
1474  *	On success msi_map::index contains the allocated index number and
1475  *	msi_map::virq the corresponding Linux interrupt number
1476  *
1477  *	On failure msi_map::index contains the error code and msi_map::virq
1478  *	is %0.
1479  */
msi_domain_alloc_irq_at(struct device * dev,unsigned int domid,unsigned int index,const struct irq_affinity_desc * affdesc,union msi_instance_cookie * icookie)1480 struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, unsigned int index,
1481 				       const struct irq_affinity_desc *affdesc,
1482 				       union msi_instance_cookie *icookie)
1483 {
1484 	struct msi_map map;
1485 
1486 	msi_lock_descs(dev);
1487 	map = __msi_domain_alloc_irq_at(dev, domid, index, affdesc, icookie);
1488 	msi_unlock_descs(dev);
1489 	return map;
1490 }
1491 
1492 /**
1493  * msi_device_domain_alloc_wired - Allocate a "wired" interrupt on @domain
1494  * @domain:	The domain to allocate on
1495  * @hwirq:	The hardware interrupt number to allocate for
1496  * @type:	The interrupt type
1497  *
1498  * This weirdness supports wire to MSI controllers like MBIGEN.
1499  *
1500  * @hwirq is the hardware interrupt number which is handed in from
1501  * irq_create_fwspec_mapping(). As the wire to MSI domain is sparse, but
1502  * sized in firmware, the hardware interrupt number cannot be used as MSI
1503  * index. For the underlying irq chip the MSI index is irrelevant and
1504  * all it needs is the hardware interrupt number.
1505  *
1506  * To handle this the MSI index is allocated with MSI_ANY_INDEX and the
1507  * hardware interrupt number is stored along with the type information in
1508  * msi_desc::cookie so the underlying interrupt chip and domain code can
1509  * retrieve it.
1510  *
1511  * Return: The Linux interrupt number (> 0) or an error code
1512  */
msi_device_domain_alloc_wired(struct irq_domain * domain,unsigned int hwirq,unsigned int type)1513 int msi_device_domain_alloc_wired(struct irq_domain *domain, unsigned int hwirq,
1514 				  unsigned int type)
1515 {
1516 	unsigned int domid = MSI_DEFAULT_DOMAIN;
1517 	union msi_instance_cookie icookie = { };
1518 	struct device *dev = domain->dev;
1519 	struct msi_map map = { };
1520 
1521 	if (WARN_ON_ONCE(!dev || domain->bus_token != DOMAIN_BUS_WIRED_TO_MSI))
1522 		return -EINVAL;
1523 
1524 	icookie.value = ((u64)type << 32) | hwirq;
1525 
1526 	msi_lock_descs(dev);
1527 	if (WARN_ON_ONCE(msi_get_device_domain(dev, domid) != domain))
1528 		map.index = -EINVAL;
1529 	else
1530 		map = __msi_domain_alloc_irq_at(dev, domid, MSI_ANY_INDEX, NULL, &icookie);
1531 	msi_unlock_descs(dev);
1532 
1533 	return map.index >= 0 ? map.virq : map.index;
1534 }
1535 
__msi_domain_free_irqs(struct device * dev,struct irq_domain * domain,struct msi_ctrl * ctrl)1536 static void __msi_domain_free_irqs(struct device *dev, struct irq_domain *domain,
1537 				   struct msi_ctrl *ctrl)
1538 {
1539 	struct xarray *xa = &dev->msi.data->__domains[ctrl->domid].store;
1540 	struct msi_domain_info *info = domain->host_data;
1541 	struct irq_data *irqd;
1542 	struct msi_desc *desc;
1543 	unsigned long idx;
1544 	int i;
1545 
1546 	xa_for_each_range(xa, idx, desc, ctrl->first, ctrl->last) {
1547 		/* Only handle MSI entries which have an interrupt associated */
1548 		if (!msi_desc_match(desc, MSI_DESC_ASSOCIATED))
1549 			continue;
1550 
1551 		/* Make sure all interrupts are deactivated */
1552 		for (i = 0; i < desc->nvec_used; i++) {
1553 			irqd = irq_domain_get_irq_data(domain, desc->irq + i);
1554 			if (irqd && irqd_is_activated(irqd))
1555 				irq_domain_deactivate_irq(irqd);
1556 		}
1557 
1558 		irq_domain_free_irqs(desc->irq, desc->nvec_used);
1559 		if (info->flags & MSI_FLAG_DEV_SYSFS)
1560 			msi_sysfs_remove_desc(dev, desc);
1561 		desc->irq = 0;
1562 	}
1563 }
1564 
msi_domain_free_locked(struct device * dev,struct msi_ctrl * ctrl)1565 static void msi_domain_free_locked(struct device *dev, struct msi_ctrl *ctrl)
1566 {
1567 	struct msi_domain_info *info;
1568 	struct msi_domain_ops *ops;
1569 	struct irq_domain *domain;
1570 
1571 	if (!msi_ctrl_valid(dev, ctrl))
1572 		return;
1573 
1574 	domain = msi_get_device_domain(dev, ctrl->domid);
1575 	if (!domain)
1576 		return;
1577 
1578 	info = domain->host_data;
1579 	ops = info->ops;
1580 
1581 	if (ops->domain_free_irqs)
1582 		ops->domain_free_irqs(domain, dev);
1583 	else
1584 		__msi_domain_free_irqs(dev, domain, ctrl);
1585 
1586 	if (ops->msi_post_free)
1587 		ops->msi_post_free(domain, dev);
1588 
1589 	if (info->flags & MSI_FLAG_FREE_MSI_DESCS)
1590 		msi_domain_free_descs(dev, ctrl);
1591 }
1592 
1593 /**
1594  * msi_domain_free_irqs_range_locked - Free a range of interrupts from a MSI interrupt domain
1595  *				       associated to @dev with msi_lock held
1596  * @dev:	Pointer to device struct of the device for which the interrupts
1597  *		are freed
1598  * @domid:	Id of the interrupt domain to operate on
1599  * @first:	First index to free (inclusive)
1600  * @last:	Last index to free (inclusive)
1601  */
msi_domain_free_irqs_range_locked(struct device * dev,unsigned int domid,unsigned int first,unsigned int last)1602 void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int domid,
1603 				       unsigned int first, unsigned int last)
1604 {
1605 	struct msi_ctrl ctrl = {
1606 		.domid	= domid,
1607 		.first	= first,
1608 		.last	= last,
1609 	};
1610 	msi_domain_free_locked(dev, &ctrl);
1611 }
1612 
1613 /**
1614  * msi_domain_free_irqs_range - Free a range of interrupts from a MSI interrupt domain
1615  *				associated to @dev
1616  * @dev:	Pointer to device struct of the device for which the interrupts
1617  *		are freed
1618  * @domid:	Id of the interrupt domain to operate on
1619  * @first:	First index to free (inclusive)
1620  * @last:	Last index to free (inclusive)
1621  */
msi_domain_free_irqs_range(struct device * dev,unsigned int domid,unsigned int first,unsigned int last)1622 void msi_domain_free_irqs_range(struct device *dev, unsigned int domid,
1623 				unsigned int first, unsigned int last)
1624 {
1625 	msi_lock_descs(dev);
1626 	msi_domain_free_irqs_range_locked(dev, domid, first, last);
1627 	msi_unlock_descs(dev);
1628 }
1629 EXPORT_SYMBOL_GPL(msi_domain_free_irqs_all);
1630 
1631 /**
1632  * msi_domain_free_irqs_all_locked - Free all interrupts from a MSI interrupt domain
1633  *				     associated to a device
1634  * @dev:	Pointer to device struct of the device for which the interrupts
1635  *		are freed
1636  * @domid:	The id of the domain to operate on
1637  *
1638  * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
1639  * pair. Use this for MSI irqdomains which implement their own vector
1640  * allocation.
1641  */
msi_domain_free_irqs_all_locked(struct device * dev,unsigned int domid)1642 void msi_domain_free_irqs_all_locked(struct device *dev, unsigned int domid)
1643 {
1644 	msi_domain_free_irqs_range_locked(dev, domid, 0,
1645 					  msi_domain_get_hwsize(dev, domid) - 1);
1646 }
1647 
1648 /**
1649  * msi_domain_free_irqs_all - Free all interrupts from a MSI interrupt domain
1650  *			      associated to a device
1651  * @dev:	Pointer to device struct of the device for which the interrupts
1652  *		are freed
1653  * @domid:	The id of the domain to operate on
1654  */
msi_domain_free_irqs_all(struct device * dev,unsigned int domid)1655 void msi_domain_free_irqs_all(struct device *dev, unsigned int domid)
1656 {
1657 	msi_lock_descs(dev);
1658 	msi_domain_free_irqs_all_locked(dev, domid);
1659 	msi_unlock_descs(dev);
1660 }
1661 
1662 /**
1663  * msi_device_domain_free_wired - Free a wired interrupt in @domain
1664  * @domain:	The domain to free the interrupt on
1665  * @virq:	The Linux interrupt number to free
1666  *
1667  * This is the counterpart of msi_device_domain_alloc_wired() for the
1668  * weird wired to MSI converting domains.
1669  */
msi_device_domain_free_wired(struct irq_domain * domain,unsigned int virq)1670 void msi_device_domain_free_wired(struct irq_domain *domain, unsigned int virq)
1671 {
1672 	struct msi_desc *desc = irq_get_msi_desc(virq);
1673 	struct device *dev = domain->dev;
1674 
1675 	if (WARN_ON_ONCE(!dev || !desc || domain->bus_token != DOMAIN_BUS_WIRED_TO_MSI))
1676 		return;
1677 
1678 	msi_lock_descs(dev);
1679 	if (!WARN_ON_ONCE(msi_get_device_domain(dev, MSI_DEFAULT_DOMAIN) != domain)) {
1680 		msi_domain_free_irqs_range_locked(dev, MSI_DEFAULT_DOMAIN, desc->msi_index,
1681 						  desc->msi_index);
1682 	}
1683 	msi_unlock_descs(dev);
1684 }
1685 
1686 /**
1687  * msi_get_domain_info - Get the MSI interrupt domain info for @domain
1688  * @domain:	The interrupt domain to retrieve data from
1689  *
1690  * Return: the pointer to the msi_domain_info stored in @domain->host_data.
1691  */
msi_get_domain_info(struct irq_domain * domain)1692 struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
1693 {
1694 	return (struct msi_domain_info *)domain->host_data;
1695 }
1696 
1697 /**
1698  * msi_device_has_isolated_msi - True if the device has isolated MSI
1699  * @dev: The device to check
1700  *
1701  * Isolated MSI means that HW modeled by an irq_domain on the path from the
1702  * initiating device to the CPU will validate that the MSI message specifies an
1703  * interrupt number that the device is authorized to trigger. This must block
1704  * devices from triggering interrupts they are not authorized to trigger.
1705  * Currently authorization means the MSI vector is one assigned to the device.
1706  *
1707  * This is interesting for securing VFIO use cases where a rouge MSI (eg created
1708  * by abusing a normal PCI MemWr DMA) must not allow the VFIO userspace to
1709  * impact outside its security domain, eg userspace triggering interrupts on
1710  * kernel drivers, a VM triggering interrupts on the hypervisor, or a VM
1711  * triggering interrupts on another VM.
1712  */
msi_device_has_isolated_msi(struct device * dev)1713 bool msi_device_has_isolated_msi(struct device *dev)
1714 {
1715 	struct irq_domain *domain = dev_get_msi_domain(dev);
1716 
1717 	for (; domain; domain = domain->parent)
1718 		if (domain->flags & IRQ_DOMAIN_FLAG_ISOLATED_MSI)
1719 			return true;
1720 	return arch_is_isolated_msi();
1721 }
1722 EXPORT_SYMBOL_GPL(msi_device_has_isolated_msi);
1723