Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1667 insertions, 0 deletions

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
new file mode 100644
index 0000000000..79b4a58ba9
--- /dev/null
+++ b/kernel/irq/msi.c
@@ -0,0 +1,1667 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014 Intel Corp.
+ * Author: Jiang Liu <jiang.liu@linux.intel.com>
+ *
+ * This file is licensed under GPLv2.
+ *
+ * This file contains common code to support Message Signaled Interrupts for
+ * PCI compatible and non PCI compatible devices.
+ */
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/pci.h>
+
+#include "internals.h"
+
+/**
+ * struct msi_ctrl - MSI internal management control structure
+ * @domid:	ID of the domain on which management operations should be done
+ * @first:	First (hardware) slot index to operate on
+ * @last:	Last (hardware) slot index to operate on
+ * @nirqs:	The number of Linux interrupts to allocate. Can be larger
+ *		than the range due to PCI/multi-MSI.
+ */
+struct msi_ctrl {
+	unsigned int			domid;
+	unsigned int			first;
+	unsigned int			last;
+	unsigned int			nirqs;
+};
+
+/* Invalid Xarray index which is outside of any searchable range */
+#define MSI_XA_MAX_INDEX	(ULONG_MAX - 1)
+/* The maximum domain size */
+#define MSI_XA_DOMAIN_SIZE	(MSI_MAX_INDEX + 1)
+
+static void msi_domain_free_locked(struct device *dev, struct msi_ctrl *ctrl);
+static unsigned int msi_domain_get_hwsize(struct device *dev, unsigned int domid);
+static inline int msi_sysfs_create_group(struct device *dev);
+
+
+/**
+ * msi_alloc_desc - Allocate an initialized msi_desc
+ * @dev:	Pointer to the device for which this is allocated
+ * @nvec:	The number of vectors used in this entry
+ * @affinity:	Optional pointer to an affinity mask array size of @nvec
+ *
+ * If @affinity is not %NULL then an affinity array[@nvec] is allocated
+ * and the affinity masks and flags from @affinity are copied.
+ *
+ * Return: pointer to allocated &msi_desc on success or %NULL on failure
+ */
+static struct msi_desc *msi_alloc_desc(struct device *dev, int nvec,
+				       const struct irq_affinity_desc *affinity)
+{
+	struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+
+	if (!desc)
+		return NULL;
+
+	desc->dev = dev;
+	desc->nvec_used = nvec;
+	if (affinity) {
+		desc->affinity = kmemdup(affinity, nvec * sizeof(*desc->affinity), GFP_KERNEL);
+		if (!desc->affinity) {
+			kfree(desc);
+			return NULL;
+		}
+	}
+	return desc;
+}
+
+static void msi_free_desc(struct msi_desc *desc)
+{
+	kfree(desc->affinity);
+	kfree(desc);
+}
+
+static int msi_insert_desc(struct device *dev, struct msi_desc *desc,
+			   unsigned int domid, unsigned int index)
+{
+	struct msi_device_data *md = dev->msi.data;
+	struct xarray *xa = &md->__domains[domid].store;
+	unsigned int hwsize;
+	int ret;
+
+	hwsize = msi_domain_get_hwsize(dev, domid);
+
+	if (index == MSI_ANY_INDEX) {
+		struct xa_limit limit = { .min = 0, .max = hwsize - 1 };
+		unsigned int index;
+
+		/* Let the xarray allocate a free index within the limit */
+		ret = xa_alloc(xa, &index, desc, limit, GFP_KERNEL);
+		if (ret)
+			goto fail;
+
+		desc->msi_index = index;
+		return 0;
+	} else {
+		if (index >= hwsize) {
+			ret = -ERANGE;
+			goto fail;
+		}
+
+		desc->msi_index = index;
+		ret = xa_insert(xa, index, desc, GFP_KERNEL);
+		if (ret)
+			goto fail;
+		return 0;
+	}
+fail:
+	msi_free_desc(desc);
+	return ret;
+}
+
+/**
+ * msi_domain_insert_msi_desc - Allocate and initialize a MSI descriptor and
+ *				insert it at @init_desc->msi_index
+ *
+ * @dev:	Pointer to the device for which the descriptor is allocated
+ * @domid:	The id of the interrupt domain to which the desriptor is added
+ * @init_desc:	Pointer to an MSI descriptor to initialize the new descriptor
+ *
+ * Return: 0 on success or an appropriate failure code.
+ */
+int msi_domain_insert_msi_desc(struct device *dev, unsigned int domid,
+			       struct msi_desc *init_desc)
+{
+	struct msi_desc *desc;
+
+	lockdep_assert_held(&dev->msi.data->mutex);
+
+	desc = msi_alloc_desc(dev, init_desc->nvec_used, init_desc->affinity);
+	if (!desc)
+		return -ENOMEM;
+
+	/* Copy type specific data to the new descriptor. */
+	desc->pci = init_desc->pci;
+
+	return msi_insert_desc(dev, desc, domid, init_desc->msi_index);
+}
+
+static bool msi_desc_match(struct msi_desc *desc, enum msi_desc_filter filter)
+{
+	switch (filter) {
+	case MSI_DESC_ALL:
+		return true;
+	case MSI_DESC_NOTASSOCIATED:
+		return !desc->irq;
+	case MSI_DESC_ASSOCIATED:
+		return !!desc->irq;
+	}
+	WARN_ON_ONCE(1);
+	return false;
+}
+
+static bool msi_ctrl_valid(struct device *dev, struct msi_ctrl *ctrl)
+{
+	unsigned int hwsize;
+
+	if (WARN_ON_ONCE(ctrl->domid >= MSI_MAX_DEVICE_IRQDOMAINS ||
+			 (dev->msi.domain &&
+			  !dev->msi.data->__domains[ctrl->domid].domain)))
+		return false;
+
+	hwsize = msi_domain_get_hwsize(dev, ctrl->domid);
+	if (WARN_ON_ONCE(ctrl->first > ctrl->last ||
+			 ctrl->first >= hwsize ||
+			 ctrl->last >= hwsize))
+		return false;
+	return true;
+}
+
+static void msi_domain_free_descs(struct device *dev, struct msi_ctrl *ctrl)
+{
+	struct msi_desc *desc;
+	struct xarray *xa;
+	unsigned long idx;
+
+	lockdep_assert_held(&dev->msi.data->mutex);
+
+	if (!msi_ctrl_valid(dev, ctrl))
+		return;
+
+	xa = &dev->msi.data->__domains[ctrl->domid].store;
+	xa_for_each_range(xa, idx, desc, ctrl->first, ctrl->last) {
+		xa_erase(xa, idx);
+
+		/* Leak the descriptor when it is still referenced */
+		if (WARN_ON_ONCE(msi_desc_match(desc, MSI_DESC_ASSOCIATED)))
+			continue;
+		msi_free_desc(desc);
+	}
+}
+
+/**
+ * msi_domain_free_msi_descs_range - Free a range of MSI descriptors of a device in an irqdomain
+ * @dev:	Device for which to free the descriptors
+ * @domid:	Id of the domain to operate on
+ * @first:	Index to start freeing from (inclusive)
+ * @last:	Last index to be freed (inclusive)
+ */
+void msi_domain_free_msi_descs_range(struct device *dev, unsigned int domid,
+				     unsigned int first, unsigned int last)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= domid,
+		.first	= first,
+		.last	= last,
+	};
+
+	msi_domain_free_descs(dev, &ctrl);
+}
+
+/**
+ * msi_domain_add_simple_msi_descs - Allocate and initialize MSI descriptors
+ * @dev:	Pointer to the device for which the descriptors are allocated
+ * @ctrl:	Allocation control struct
+ *
+ * Return: 0 on success or an appropriate failure code.
+ */
+static int msi_domain_add_simple_msi_descs(struct device *dev, struct msi_ctrl *ctrl)
+{
+	struct msi_desc *desc;
+	unsigned int idx;
+	int ret;
+
+	lockdep_assert_held(&dev->msi.data->mutex);
+
+	if (!msi_ctrl_valid(dev, ctrl))
+		return -EINVAL;
+
+	for (idx = ctrl->first; idx <= ctrl->last; idx++) {
+		desc = msi_alloc_desc(dev, 1, NULL);
+		if (!desc)
+			goto fail_mem;
+		ret = msi_insert_desc(dev, desc, ctrl->domid, idx);
+		if (ret)
+			goto fail;
+	}
+	return 0;
+
+fail_mem:
+	ret = -ENOMEM;
+fail:
+	msi_domain_free_descs(dev, ctrl);
+	return ret;
+}
+
+void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
+	*msg = entry->msg;
+}
+
+void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
+{
+	struct msi_desc *entry = irq_get_msi_desc(irq);
+
+	__get_cached_msi_msg(entry, msg);
+}
+EXPORT_SYMBOL_GPL(get_cached_msi_msg);
+
+static void msi_device_data_release(struct device *dev, void *res)
+{
+	struct msi_device_data *md = res;
+	int i;
+
+	for (i = 0; i < MSI_MAX_DEVICE_IRQDOMAINS; i++) {
+		msi_remove_device_irq_domain(dev, i);
+		WARN_ON_ONCE(!xa_empty(&md->__domains[i].store));
+		xa_destroy(&md->__domains[i].store);
+	}
+	dev->msi.data = NULL;
+}
+
+/**
+ * msi_setup_device_data - Setup MSI device data
+ * @dev:	Device for which MSI device data should be set up
+ *
+ * Return: 0 on success, appropriate error code otherwise
+ *
+ * This can be called more than once for @dev. If the MSI device data is
+ * already allocated the call succeeds. The allocated memory is
+ * automatically released when the device is destroyed.
+ */
+int msi_setup_device_data(struct device *dev)
+{
+	struct msi_device_data *md;
+	int ret, i;
+
+	if (dev->msi.data)
+		return 0;
+
+	md = devres_alloc(msi_device_data_release, sizeof(*md), GFP_KERNEL);
+	if (!md)
+		return -ENOMEM;
+
+	ret = msi_sysfs_create_group(dev);
+	if (ret) {
+		devres_free(md);
+		return ret;
+	}
+
+	for (i = 0; i < MSI_MAX_DEVICE_IRQDOMAINS; i++)
+		xa_init_flags(&md->__domains[i].store, XA_FLAGS_ALLOC);
+
+	/*
+	 * If @dev::msi::domain is set and is a global MSI domain, copy the
+	 * pointer into the domain array so all code can operate on domain
+	 * ids. The NULL pointer check is required to keep the legacy
+	 * architecture specific PCI/MSI support working.
+	 */
+	if (dev->msi.domain && !irq_domain_is_msi_parent(dev->msi.domain))
+		md->__domains[MSI_DEFAULT_DOMAIN].domain = dev->msi.domain;
+
+	mutex_init(&md->mutex);
+	dev->msi.data = md;
+	devres_add(dev, md);
+	return 0;
+}
+
+/**
+ * msi_lock_descs - Lock the MSI descriptor storage of a device
+ * @dev:	Device to operate on
+ */
+void msi_lock_descs(struct device *dev)
+{
+	mutex_lock(&dev->msi.data->mutex);
+}
+EXPORT_SYMBOL_GPL(msi_lock_descs);
+
+/**
+ * msi_unlock_descs - Unlock the MSI descriptor storage of a device
+ * @dev:	Device to operate on
+ */
+void msi_unlock_descs(struct device *dev)
+{
+	/* Invalidate the index which was cached by the iterator */
+	dev->msi.data->__iter_idx = MSI_XA_MAX_INDEX;
+	mutex_unlock(&dev->msi.data->mutex);
+}
+EXPORT_SYMBOL_GPL(msi_unlock_descs);
+
+static struct msi_desc *msi_find_desc(struct msi_device_data *md, unsigned int domid,
+				      enum msi_desc_filter filter)
+{
+	struct xarray *xa = &md->__domains[domid].store;
+	struct msi_desc *desc;
+
+	xa_for_each_start(xa, md->__iter_idx, desc, md->__iter_idx) {
+		if (msi_desc_match(desc, filter))
+			return desc;
+	}
+	md->__iter_idx = MSI_XA_MAX_INDEX;
+	return NULL;
+}
+
+/**
+ * msi_domain_first_desc - Get the first MSI descriptor of an irqdomain associated to a device
+ * @dev:	Device to operate on
+ * @domid:	The id of the interrupt domain which should be walked.
+ * @filter:	Descriptor state filter
+ *
+ * Must be called with the MSI descriptor mutex held, i.e. msi_lock_descs()
+ * must be invoked before the call.
+ *
+ * Return: Pointer to the first MSI descriptor matching the search
+ *	   criteria, NULL if none found.
+ */
+struct msi_desc *msi_domain_first_desc(struct device *dev, unsigned int domid,
+				       enum msi_desc_filter filter)
+{
+	struct msi_device_data *md = dev->msi.data;
+
+	if (WARN_ON_ONCE(!md || domid >= MSI_MAX_DEVICE_IRQDOMAINS))
+		return NULL;
+
+	lockdep_assert_held(&md->mutex);
+
+	md->__iter_idx = 0;
+	return msi_find_desc(md, domid, filter);
+}
+EXPORT_SYMBOL_GPL(msi_domain_first_desc);
+
+/**
+ * msi_next_desc - Get the next MSI descriptor of a device
+ * @dev:	Device to operate on
+ * @domid:	The id of the interrupt domain which should be walked.
+ * @filter:	Descriptor state filter
+ *
+ * The first invocation of msi_next_desc() has to be preceeded by a
+ * successful invocation of __msi_first_desc(). Consecutive invocations are
+ * only valid if the previous one was successful. All these operations have
+ * to be done within the same MSI mutex held region.
+ *
+ * Return: Pointer to the next MSI descriptor matching the search
+ *	   criteria, NULL if none found.
+ */
+struct msi_desc *msi_next_desc(struct device *dev, unsigned int domid,
+			       enum msi_desc_filter filter)
+{
+	struct msi_device_data *md = dev->msi.data;
+
+	if (WARN_ON_ONCE(!md || domid >= MSI_MAX_DEVICE_IRQDOMAINS))
+		return NULL;
+
+	lockdep_assert_held(&md->mutex);
+
+	if (md->__iter_idx >= (unsigned long)MSI_MAX_INDEX)
+		return NULL;
+
+	md->__iter_idx++;
+	return msi_find_desc(md, domid, filter);
+}
+EXPORT_SYMBOL_GPL(msi_next_desc);
+
+/**
+ * msi_domain_get_virq - Lookup the Linux interrupt number for a MSI index on a interrupt domain
+ * @dev:	Device to operate on
+ * @domid:	Domain ID of the interrupt domain associated to the device
+ * @index:	MSI interrupt index to look for (0-based)
+ *
+ * Return: The Linux interrupt number on success (> 0), 0 if not found
+ */
+unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index)
+{
+	struct msi_desc *desc;
+	unsigned int ret = 0;
+	bool pcimsi = false;
+	struct xarray *xa;
+
+	if (!dev->msi.data)
+		return 0;
+
+	if (WARN_ON_ONCE(index > MSI_MAX_INDEX || domid >= MSI_MAX_DEVICE_IRQDOMAINS))
+		return 0;
+
+	/* This check is only valid for the PCI default MSI domain */
+	if (dev_is_pci(dev) && domid == MSI_DEFAULT_DOMAIN)
+		pcimsi = to_pci_dev(dev)->msi_enabled;
+
+	msi_lock_descs(dev);
+	xa = &dev->msi.data->__domains[domid].store;
+	desc = xa_load(xa, pcimsi ? 0 : index);
+	if (desc && desc->irq) {
+		/*
+		 * PCI-MSI has only one descriptor for multiple interrupts.
+		 * PCI-MSIX and platform MSI use a descriptor per
+		 * interrupt.
+		 */
+		if (pcimsi) {
+			if (index < desc->nvec_used)
+				ret = desc->irq + index;
+		} else {
+			ret = desc->irq;
+		}
+	}
+
+	msi_unlock_descs(dev);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(msi_domain_get_virq);
+
+#ifdef CONFIG_SYSFS
+static struct attribute *msi_dev_attrs[] = {
+	NULL
+};
+
+static const struct attribute_group msi_irqs_group = {
+	.name	= "msi_irqs",
+	.attrs	= msi_dev_attrs,
+};
+
+static inline int msi_sysfs_create_group(struct device *dev)
+{
+	return devm_device_add_group(dev, &msi_irqs_group);
+}
+
+static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	/* MSI vs. MSIX is per device not per interrupt */
+	bool is_msix = dev_is_pci(dev) ? to_pci_dev(dev)->msix_enabled : false;
+
+	return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi");
+}
+
+static void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc)
+{
+	struct device_attribute *attrs = desc->sysfs_attrs;
+	int i;
+
+	if (!attrs)
+		return;
+
+	desc->sysfs_attrs = NULL;
+	for (i = 0; i < desc->nvec_used; i++) {
+		if (attrs[i].show)
+			sysfs_remove_file_from_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
+		kfree(attrs[i].attr.name);
+	}
+	kfree(attrs);
+}
+
+static int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc)
+{
+	struct device_attribute *attrs;
+	int ret, i;
+
+	attrs = kcalloc(desc->nvec_used, sizeof(*attrs), GFP_KERNEL);
+	if (!attrs)
+		return -ENOMEM;
+
+	desc->sysfs_attrs = attrs;
+	for (i = 0; i < desc->nvec_used; i++) {
+		sysfs_attr_init(&attrs[i].attr);
+		attrs[i].attr.name = kasprintf(GFP_KERNEL, "%d", desc->irq + i);
+		if (!attrs[i].attr.name) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		attrs[i].attr.mode = 0444;
+		attrs[i].show = msi_mode_show;
+
+		ret = sysfs_add_file_to_group(&dev->kobj, &attrs[i].attr, msi_irqs_group.name);
+		if (ret) {
+			attrs[i].show = NULL;
+			goto fail;
+		}
+	}
+	return 0;
+
+fail:
+	msi_sysfs_remove_desc(dev, desc);
+	return ret;
+}
+
+#if defined(CONFIG_PCI_MSI_ARCH_FALLBACKS) || defined(CONFIG_PCI_XEN)
+/**
+ * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
+ * @dev:	The device (PCI, platform etc) which will get sysfs entries
+ */
+int msi_device_populate_sysfs(struct device *dev)
+{
+	struct msi_desc *desc;
+	int ret;
+
+	msi_for_each_desc(desc, dev, MSI_DESC_ASSOCIATED) {
+		if (desc->sysfs_attrs)
+			continue;
+		ret = msi_sysfs_populate_desc(dev, desc);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+/**
+ * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
+ * @dev:		The device (PCI, platform etc) for which to remove
+ *			sysfs entries
+ */
+void msi_device_destroy_sysfs(struct device *dev)
+{
+	struct msi_desc *desc;
+
+	msi_for_each_desc(desc, dev, MSI_DESC_ALL)
+		msi_sysfs_remove_desc(dev, desc);
+}
+#endif /* CONFIG_PCI_MSI_ARCH_FALLBACK || CONFIG_PCI_XEN */
+#else /* CONFIG_SYSFS */
+static inline int msi_sysfs_create_group(struct device *dev) { return 0; }
+static inline int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc) { return 0; }
+static inline void msi_sysfs_remove_desc(struct device *dev, struct msi_desc *desc) { }
+#endif /* !CONFIG_SYSFS */
+
+static struct irq_domain *msi_get_device_domain(struct device *dev, unsigned int domid)
+{
+	struct irq_domain *domain;
+
+	lockdep_assert_held(&dev->msi.data->mutex);
+
+	if (WARN_ON_ONCE(domid >= MSI_MAX_DEVICE_IRQDOMAINS))
+		return NULL;
+
+	domain = dev->msi.data->__domains[domid].domain;
+	if (!domain)
+		return NULL;
+
+	if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain)))
+		return NULL;
+
+	return domain;
+}
+
+static unsigned int msi_domain_get_hwsize(struct device *dev, unsigned int domid)
+{
+	struct msi_domain_info *info;
+	struct irq_domain *domain;
+
+	domain = msi_get_device_domain(dev, domid);
+	if (domain) {
+		info = domain->host_data;
+		return info->hwsize;
+	}
+	/* No domain, default to MSI_XA_DOMAIN_SIZE */
+	return MSI_XA_DOMAIN_SIZE;
+}
+
+static inline void irq_chip_write_msi_msg(struct irq_data *data,
+					  struct msi_msg *msg)
+{
+	data->chip->irq_write_msi_msg(data, msg);
+}
+
+static void msi_check_level(struct irq_domain *domain, struct msi_msg *msg)
+{
+	struct msi_domain_info *info = domain->host_data;
+
+	/*
+	 * If the MSI provider has messed with the second message and
+	 * not advertized that it is level-capable, signal the breakage.
+	 */
+	WARN_ON(!((info->flags & MSI_FLAG_LEVEL_CAPABLE) &&
+		  (info->chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)) &&
+		(msg[1].address_lo || msg[1].address_hi || msg[1].data));
+}
+
+/**
+ * msi_domain_set_affinity - Generic affinity setter function for MSI domains
+ * @irq_data:	The irq data associated to the interrupt
+ * @mask:	The affinity mask to set
+ * @force:	Flag to enforce setting (disable online checks)
+ *
+ * Intended to be used by MSI interrupt controllers which are
+ * implemented with hierarchical domains.
+ *
+ * Return: IRQ_SET_MASK_* result code
+ */
+int msi_domain_set_affinity(struct irq_data *irq_data,
+			    const struct cpumask *mask, bool force)
+{
+	struct irq_data *parent = irq_data->parent_data;
+	struct msi_msg msg[2] = { [1] = { }, };
+	int ret;
+
+	ret = parent->chip->irq_set_affinity(parent, mask, force);
+	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) {
+		BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
+		msi_check_level(irq_data->domain, msg);
+		irq_chip_write_msi_msg(irq_data, msg);
+	}
+
+	return ret;
+}
+
+static int msi_domain_activate(struct irq_domain *domain,
+			       struct irq_data *irq_data, bool early)
+{
+	struct msi_msg msg[2] = { [1] = { }, };
+
+	BUG_ON(irq_chip_compose_msi_msg(irq_data, msg));
+	msi_check_level(irq_data->domain, msg);
+	irq_chip_write_msi_msg(irq_data, msg);
+	return 0;
+}
+
+static void msi_domain_deactivate(struct irq_domain *domain,
+				  struct irq_data *irq_data)
+{
+	struct msi_msg msg[2];
+
+	memset(msg, 0, sizeof(msg));
+	irq_chip_write_msi_msg(irq_data, msg);
+}
+
+static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+			    unsigned int nr_irqs, void *arg)
+{
+	struct msi_domain_info *info = domain->host_data;
+	struct msi_domain_ops *ops = info->ops;
+	irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
+	int i, ret;
+
+	if (irq_find_mapping(domain, hwirq) > 0)
+		return -EEXIST;
+
+	if (domain->parent) {
+		ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
+		if (ret < 0)
+			return ret;
+	}
+
+	for (i = 0; i < nr_irqs; i++) {
+		ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg);
+		if (ret < 0) {
+			if (ops->msi_free) {
+				for (i--; i > 0; i--)
+					ops->msi_free(domain, info, virq + i);
+			}
+			irq_domain_free_irqs_top(domain, virq, nr_irqs);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void msi_domain_free(struct irq_domain *domain, unsigned int virq,
+			    unsigned int nr_irqs)
+{
+	struct msi_domain_info *info = domain->host_data;
+	int i;
+
+	if (info->ops->msi_free) {
+		for (i = 0; i < nr_irqs; i++)
+			info->ops->msi_free(domain, info, virq + i);
+	}
+	irq_domain_free_irqs_top(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+	.alloc		= msi_domain_alloc,
+	.free		= msi_domain_free,
+	.activate	= msi_domain_activate,
+	.deactivate	= msi_domain_deactivate,
+};
+
+static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,
+						msi_alloc_info_t *arg)
+{
+	return arg->hwirq;
+}
+
+static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev,
+				  int nvec, msi_alloc_info_t *arg)
+{
+	memset(arg, 0, sizeof(*arg));
+	return 0;
+}
+
+static void msi_domain_ops_set_desc(msi_alloc_info_t *arg,
+				    struct msi_desc *desc)
+{
+	arg->desc = desc;
+}
+
+static int 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)
+{
+	irq_domain_set_hwirq_and_chip(domain, virq, hwirq, info->chip,
+				      info->chip_data);
+	if (info->handler && info->handler_name) {
+		__irq_set_handler(virq, info->handler, 0, info->handler_name);
+		if (info->handler_data)
+			irq_set_handler_data(virq, info->handler_data);
+	}
+	return 0;
+}
+
+static struct msi_domain_ops msi_domain_ops_default = {
+	.get_hwirq		= msi_domain_ops_get_hwirq,
+	.msi_init		= msi_domain_ops_init,
+	.msi_prepare		= msi_domain_ops_prepare,
+	.set_desc		= msi_domain_ops_set_desc,
+};
+
+static void msi_domain_update_dom_ops(struct msi_domain_info *info)
+{
+	struct msi_domain_ops *ops = info->ops;
+
+	if (ops == NULL) {
+		info->ops = &msi_domain_ops_default;
+		return;
+	}
+
+	if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
+		return;
+
+	if (ops->get_hwirq == NULL)
+		ops->get_hwirq = msi_domain_ops_default.get_hwirq;
+	if (ops->msi_init == NULL)
+		ops->msi_init = msi_domain_ops_default.msi_init;
+	if (ops->msi_prepare == NULL)
+		ops->msi_prepare = msi_domain_ops_default.msi_prepare;
+	if (ops->set_desc == NULL)
+		ops->set_desc = msi_domain_ops_default.set_desc;
+}
+
+static void msi_domain_update_chip_ops(struct msi_domain_info *info)
+{
+	struct irq_chip *chip = info->chip;
+
+	BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
+	if (!chip->irq_set_affinity)
+		chip->irq_set_affinity = msi_domain_set_affinity;
+}
+
+static struct irq_domain *__msi_create_irq_domain(struct fwnode_handle *fwnode,
+						  struct msi_domain_info *info,
+						  unsigned int flags,
+						  struct irq_domain *parent)
+{
+	struct irq_domain *domain;
+
+	if (info->hwsize > MSI_XA_DOMAIN_SIZE)
+		return NULL;
+
+	/*
+	 * Hardware size 0 is valid for backwards compatibility and for
+	 * domains which are not backed by a hardware table. Grant the
+	 * maximum index space.
+	 */
+	if (!info->hwsize)
+		info->hwsize = MSI_XA_DOMAIN_SIZE;
+
+	msi_domain_update_dom_ops(info);
+	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
+		msi_domain_update_chip_ops(info);
+
+	domain = irq_domain_create_hierarchy(parent, flags | IRQ_DOMAIN_FLAG_MSI, 0,
+					     fwnode, &msi_domain_ops, info);
+
+	if (domain)
+		irq_domain_update_bus_token(domain, info->bus_token);
+
+	return domain;
+}
+
+/**
+ * msi_create_irq_domain - Create an MSI interrupt domain
+ * @fwnode:	Optional fwnode of the interrupt controller
+ * @info:	MSI domain info
+ * @parent:	Parent irq domain
+ *
+ * Return: pointer to the created &struct irq_domain or %NULL on failure
+ */
+struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
+					 struct msi_domain_info *info,
+					 struct irq_domain *parent)
+{
+	return __msi_create_irq_domain(fwnode, info, 0, parent);
+}
+
+/**
+ * msi_parent_init_dev_msi_info - Delegate initialization of device MSI info down
+ *				  in the domain hierarchy
+ * @dev:		The device for which the domain should be created
+ * @domain:		The domain in the hierarchy this op is being called on
+ * @msi_parent_domain:	The IRQ_DOMAIN_FLAG_MSI_PARENT domain for the child to
+ *			be created
+ * @msi_child_info:	The MSI domain info of the IRQ_DOMAIN_FLAG_MSI_DEVICE
+ *			domain to be created
+ *
+ * Return: true on success, false otherwise
+ *
+ * This is the most complex problem of per device MSI domains and the
+ * underlying interrupt domain hierarchy:
+ *
+ * The device domain to be initialized requests the broadest feature set
+ * possible and the underlying domain hierarchy puts restrictions on it.
+ *
+ * That's trivial for a simple parent->child relationship, but it gets
+ * interesting with an intermediate domain: root->parent->child.  The
+ * intermediate 'parent' can expand the capabilities which the 'root'
+ * domain is providing. So that creates a classic hen and egg problem:
+ * Which entity is doing the restrictions/expansions?
+ *
+ * One solution is to let the root domain handle the initialization that's
+ * why there is the @domain and the @msi_parent_domain pointer.
+ */
+bool 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)
+{
+	struct irq_domain *parent = domain->parent;
+
+	if (WARN_ON_ONCE(!parent || !parent->msi_parent_ops ||
+			 !parent->msi_parent_ops->init_dev_msi_info))
+		return false;
+
+	return parent->msi_parent_ops->init_dev_msi_info(dev, parent, msi_parent_domain,
+							 msi_child_info);
+}
+
+/**
+ * msi_create_device_irq_domain - Create a device MSI interrupt domain
+ * @dev:		Pointer to the device
+ * @domid:		Domain id
+ * @template:		MSI domain info bundle used as template
+ * @hwsize:		Maximum number of MSI table entries (0 if unknown or unlimited)
+ * @domain_data:	Optional pointer to domain specific data which is set in
+ *			msi_domain_info::data
+ * @chip_data:		Optional pointer to chip specific data which is set in
+ *			msi_domain_info::chip_data
+ *
+ * Return: True on success, false otherwise
+ *
+ * There is no firmware node required for this interface because the per
+ * device domains are software constructs which are actually closer to the
+ * hardware reality than any firmware can describe them.
+ *
+ * The domain name and the irq chip name for a MSI device domain are
+ * composed by: "$(PREFIX)$(CHIPNAME)-$(DEVNAME)"
+ *
+ * $PREFIX:   Optional prefix provided by the underlying MSI parent domain
+ *	      via msi_parent_ops::prefix. If that pointer is NULL the prefix
+ *	      is empty.
+ * $CHIPNAME: The name of the irq_chip in @template
+ * $DEVNAME:  The name of the device
+ *
+ * This results in understandable chip names and hardware interrupt numbers
+ * in e.g. /proc/interrupts
+ *
+ * PCI-MSI-0000:00:1c.0     0-edge  Parent domain has no prefix
+ * IR-PCI-MSI-0000:00:1c.4  0-edge  Same with interrupt remapping prefix 'IR-'
+ *
+ * IR-PCI-MSIX-0000:3d:00.0 0-edge  Hardware interrupt numbers reflect
+ * IR-PCI-MSIX-0000:3d:00.0 1-edge  the real MSI-X index on that device
+ * IR-PCI-MSIX-0000:3d:00.0 2-edge
+ *
+ * On IMS domains the hardware interrupt number is either a table entry
+ * index or a purely software managed index but it is guaranteed to be
+ * unique.
+ *
+ * The domain pointer is stored in @dev::msi::data::__irqdomains[]. All
+ * subsequent operations on the domain depend on the domain id.
+ *
+ * The domain is automatically freed when the device is removed via devres
+ * in the context of @dev::msi::data freeing, but it can also be
+ * independently removed via @msi_remove_device_irq_domain().
+ */
+bool 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)
+{
+	struct irq_domain *domain, *parent = dev->msi.domain;
+	const struct msi_parent_ops *pops;
+	struct msi_domain_template *bundle;
+	struct fwnode_handle *fwnode;
+
+	if (!irq_domain_is_msi_parent(parent))
+		return false;
+
+	if (domid >= MSI_MAX_DEVICE_IRQDOMAINS)
+		return false;
+
+	bundle = kmemdup(template, sizeof(*bundle), GFP_KERNEL);
+	if (!bundle)
+		return false;
+
+	bundle->info.hwsize = hwsize;
+	bundle->info.chip = &bundle->chip;
+	bundle->info.ops = &bundle->ops;
+	bundle->info.data = domain_data;
+	bundle->info.chip_data = chip_data;
+
+	pops = parent->msi_parent_ops;
+	snprintf(bundle->name, sizeof(bundle->name), "%s%s-%s",
+		 pops->prefix ? : "", bundle->chip.name, dev_name(dev));
+	bundle->chip.name = bundle->name;
+
+	fwnode = irq_domain_alloc_named_fwnode(bundle->name);
+	if (!fwnode)
+		goto free_bundle;
+
+	if (msi_setup_device_data(dev))
+		goto free_fwnode;
+
+	msi_lock_descs(dev);
+
+	if (WARN_ON_ONCE(msi_get_device_domain(dev, domid)))
+		goto fail;
+
+	if (!pops->init_dev_msi_info(dev, parent, parent, &bundle->info))
+		goto fail;
+
+	domain = __msi_create_irq_domain(fwnode, &bundle->info, IRQ_DOMAIN_FLAG_MSI_DEVICE, parent);
+	if (!domain)
+		goto fail;
+
+	domain->dev = dev;
+	dev->msi.data->__domains[domid].domain = domain;
+	msi_unlock_descs(dev);
+	return true;
+
+fail:
+	msi_unlock_descs(dev);
+free_fwnode:
+	irq_domain_free_fwnode(fwnode);
+free_bundle:
+	kfree(bundle);
+	return false;
+}
+
+/**
+ * msi_remove_device_irq_domain - Free a device MSI interrupt domain
+ * @dev:	Pointer to the device
+ * @domid:	Domain id
+ */
+void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
+{
+	struct fwnode_handle *fwnode = NULL;
+	struct msi_domain_info *info;
+	struct irq_domain *domain;
+
+	msi_lock_descs(dev);
+
+	domain = msi_get_device_domain(dev, domid);
+
+	if (!domain || !irq_domain_is_msi_device(domain))
+		goto unlock;
+
+	dev->msi.data->__domains[domid].domain = NULL;
+	info = domain->host_data;
+	if (irq_domain_is_msi_device(domain))
+		fwnode = domain->fwnode;
+	irq_domain_remove(domain);
+	irq_domain_free_fwnode(fwnode);
+	kfree(container_of(info, struct msi_domain_template, info));
+
+unlock:
+	msi_unlock_descs(dev);
+}
+
+/**
+ * msi_match_device_irq_domain - Match a device irq domain against a bus token
+ * @dev:	Pointer to the device
+ * @domid:	Domain id
+ * @bus_token:	Bus token to match against the domain bus token
+ *
+ * Return: True if device domain exists and bus tokens match.
+ */
+bool msi_match_device_irq_domain(struct device *dev, unsigned int domid,
+				 enum irq_domain_bus_token bus_token)
+{
+	struct msi_domain_info *info;
+	struct irq_domain *domain;
+	bool ret = false;
+
+	msi_lock_descs(dev);
+	domain = msi_get_device_domain(dev, domid);
+	if (domain && irq_domain_is_msi_device(domain)) {
+		info = domain->host_data;
+		ret = info->bus_token == bus_token;
+	}
+	msi_unlock_descs(dev);
+	return ret;
+}
+
+int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
+			    int nvec, msi_alloc_info_t *arg)
+{
+	struct msi_domain_info *info = domain->host_data;
+	struct msi_domain_ops *ops = info->ops;
+
+	return ops->msi_prepare(domain, dev, nvec, arg);
+}
+
+int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
+			     int virq_base, int nvec, msi_alloc_info_t *arg)
+{
+	struct msi_domain_info *info = domain->host_data;
+	struct msi_domain_ops *ops = info->ops;
+	struct msi_ctrl ctrl = {
+		.domid	= MSI_DEFAULT_DOMAIN,
+		.first  = virq_base,
+		.last	= virq_base + nvec - 1,
+	};
+	struct msi_desc *desc;
+	struct xarray *xa;
+	int ret, virq;
+
+	msi_lock_descs(dev);
+
+	if (!msi_ctrl_valid(dev, &ctrl)) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	ret = msi_domain_add_simple_msi_descs(dev, &ctrl);
+	if (ret)
+		goto unlock;
+
+	xa = &dev->msi.data->__domains[ctrl.domid].store;
+
+	for (virq = virq_base; virq < virq_base + nvec; virq++) {
+		desc = xa_load(xa, virq);
+		desc->irq = virq;
+
+		ops->set_desc(arg, desc);
+		ret = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
+		if (ret)
+			goto fail;
+
+		irq_set_msi_desc(virq, desc);
+	}
+	msi_unlock_descs(dev);
+	return 0;
+
+fail:
+	for (--virq; virq >= virq_base; virq--) {
+		msi_domain_depopulate_descs(dev, virq, 1);
+		irq_domain_free_irqs_common(domain, virq, 1);
+	}
+	msi_domain_free_descs(dev, &ctrl);
+unlock:
+	msi_unlock_descs(dev);
+	return ret;
+}
+
+void msi_domain_depopulate_descs(struct device *dev, int virq_base, int nvec)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= MSI_DEFAULT_DOMAIN,
+		.first  = virq_base,
+		.last	= virq_base + nvec - 1,
+	};
+	struct msi_desc *desc;
+	struct xarray *xa;
+	unsigned long idx;
+
+	if (!msi_ctrl_valid(dev, &ctrl))
+		return;
+
+	xa = &dev->msi.data->__domains[ctrl.domid].store;
+	xa_for_each_range(xa, idx, desc, ctrl.first, ctrl.last)
+		desc->irq = 0;
+}
+
+/*
+ * Carefully check whether the device can use reservation mode. If
+ * reservation mode is enabled then the early activation will assign a
+ * dummy vector to the device. If the PCI/MSI device does not support
+ * masking of the entry then this can result in spurious interrupts when
+ * the device driver is not absolutely careful. But even then a malfunction
+ * of the hardware could result in a spurious interrupt on the dummy vector
+ * and render the device unusable. If the entry can be masked then the core
+ * logic will prevent the spurious interrupt and reservation mode can be
+ * used. For now reservation mode is restricted to PCI/MSI.
+ */
+static bool msi_check_reservation_mode(struct irq_domain *domain,
+				       struct msi_domain_info *info,
+				       struct device *dev)
+{
+	struct msi_desc *desc;
+
+	switch(domain->bus_token) {
+	case DOMAIN_BUS_PCI_MSI:
+	case DOMAIN_BUS_PCI_DEVICE_MSI:
+	case DOMAIN_BUS_PCI_DEVICE_MSIX:
+	case DOMAIN_BUS_VMD_MSI:
+		break;
+	default:
+		return false;
+	}
+
+	if (!(info->flags & MSI_FLAG_MUST_REACTIVATE))
+		return false;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask)
+		return false;
+
+	/*
+	 * Checking the first MSI descriptor is sufficient. MSIX supports
+	 * masking and MSI does so when the can_mask attribute is set.
+	 */
+	desc = msi_first_desc(dev, MSI_DESC_ALL);
+	return desc->pci.msi_attrib.is_msix || desc->pci.msi_attrib.can_mask;
+}
+
+static int msi_handle_pci_fail(struct irq_domain *domain, struct msi_desc *desc,
+			       int allocated)
+{
+	switch(domain->bus_token) {
+	case DOMAIN_BUS_PCI_MSI:
+	case DOMAIN_BUS_PCI_DEVICE_MSI:
+	case DOMAIN_BUS_PCI_DEVICE_MSIX:
+	case DOMAIN_BUS_VMD_MSI:
+		if (IS_ENABLED(CONFIG_PCI_MSI))
+			break;
+		fallthrough;
+	default:
+		return -ENOSPC;
+	}
+
+	/* Let a failed PCI multi MSI allocation retry */
+	if (desc->nvec_used > 1)
+		return 1;
+
+	/* If there was a successful allocation let the caller know */
+	return allocated ? allocated : -ENOSPC;
+}
+
+#define VIRQ_CAN_RESERVE	0x01
+#define VIRQ_ACTIVATE		0x02
+
+static int msi_init_virq(struct irq_domain *domain, int virq, unsigned int vflags)
+{
+	struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
+	int ret;
+
+	if (!(vflags & VIRQ_CAN_RESERVE)) {
+		irqd_clr_can_reserve(irqd);
+
+		/*
+		 * If the interrupt is managed but no CPU is available to
+		 * service it, shut it down until better times. Note that
+		 * we only do this on the !RESERVE path as x86 (the only
+		 * architecture using this flag) deals with this in a
+		 * different way by using a catch-all vector.
+		 */
+		if ((vflags & VIRQ_ACTIVATE) &&
+		    irqd_affinity_is_managed(irqd) &&
+		    !cpumask_intersects(irq_data_get_affinity_mask(irqd),
+					cpu_online_mask)) {
+			    irqd_set_managed_shutdown(irqd);
+			    return 0;
+		    }
+	}
+
+	if (!(vflags & VIRQ_ACTIVATE))
+		return 0;
+
+	ret = irq_domain_activate_irq(irqd, vflags & VIRQ_CAN_RESERVE);
+	if (ret)
+		return ret;
+	/*
+	 * If the interrupt uses reservation mode, clear the activated bit
+	 * so request_irq() will assign the final vector.
+	 */
+	if (vflags & VIRQ_CAN_RESERVE)
+		irqd_clr_activated(irqd);
+	return 0;
+}
+
+static int __msi_domain_alloc_irqs(struct device *dev, struct irq_domain *domain,
+				   struct msi_ctrl *ctrl)
+{
+	struct xarray *xa = &dev->msi.data->__domains[ctrl->domid].store;
+	struct msi_domain_info *info = domain->host_data;
+	struct msi_domain_ops *ops = info->ops;
+	unsigned int vflags = 0, allocated = 0;
+	msi_alloc_info_t arg = { };
+	struct msi_desc *desc;
+	unsigned long idx;
+	int i, ret, virq;
+
+	ret = msi_domain_prepare_irqs(domain, dev, ctrl->nirqs, &arg);
+	if (ret)
+		return ret;
+
+	/*
+	 * This flag is set by the PCI layer as we need to activate
+	 * the MSI entries before the PCI layer enables MSI in the
+	 * card. Otherwise the card latches a random msi message.
+	 */
+	if (info->flags & MSI_FLAG_ACTIVATE_EARLY)
+		vflags |= VIRQ_ACTIVATE;
+
+	/*
+	 * Interrupt can use a reserved vector and will not occupy
+	 * a real device vector until the interrupt is requested.
+	 */
+	if (msi_check_reservation_mode(domain, info, dev))
+		vflags |= VIRQ_CAN_RESERVE;
+
+	xa_for_each_range(xa, idx, desc, ctrl->first, ctrl->last) {
+		if (!msi_desc_match(desc, MSI_DESC_NOTASSOCIATED))
+			continue;
+
+		/* This should return -ECONFUSED... */
+		if (WARN_ON_ONCE(allocated >= ctrl->nirqs))
+			return -EINVAL;
+
+		if (ops->prepare_desc)
+			ops->prepare_desc(domain, &arg, desc);
+
+		ops->set_desc(&arg, desc);
+
+		virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,
+					       dev_to_node(dev), &arg, false,
+					       desc->affinity);
+		if (virq < 0)
+			return msi_handle_pci_fail(domain, desc, allocated);
+
+		for (i = 0; i < desc->nvec_used; i++) {
+			irq_set_msi_desc_off(virq, i, desc);
+			irq_debugfs_copy_devname(virq + i, dev);
+			ret = msi_init_virq(domain, virq + i, vflags);
+			if (ret)
+				return ret;
+		}
+		if (info->flags & MSI_FLAG_DEV_SYSFS) {
+			ret = msi_sysfs_populate_desc(dev, desc);
+			if (ret)
+				return ret;
+		}
+		allocated++;
+	}
+	return 0;
+}
+
+static int msi_domain_alloc_simple_msi_descs(struct device *dev,
+					     struct msi_domain_info *info,
+					     struct msi_ctrl *ctrl)
+{
+	if (!(info->flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS))
+		return 0;
+
+	return msi_domain_add_simple_msi_descs(dev, ctrl);
+}
+
+static int __msi_domain_alloc_locked(struct device *dev, struct msi_ctrl *ctrl)
+{
+	struct msi_domain_info *info;
+	struct msi_domain_ops *ops;
+	struct irq_domain *domain;
+	int ret;
+
+	if (!msi_ctrl_valid(dev, ctrl))
+		return -EINVAL;
+
+	domain = msi_get_device_domain(dev, ctrl->domid);
+	if (!domain)
+		return -ENODEV;
+
+	info = domain->host_data;
+
+	ret = msi_domain_alloc_simple_msi_descs(dev, info, ctrl);
+	if (ret)
+		return ret;
+
+	ops = info->ops;
+	if (ops->domain_alloc_irqs)
+		return ops->domain_alloc_irqs(domain, dev, ctrl->nirqs);
+
+	return __msi_domain_alloc_irqs(dev, domain, ctrl);
+}
+
+static int msi_domain_alloc_locked(struct device *dev, struct msi_ctrl *ctrl)
+{
+	int ret = __msi_domain_alloc_locked(dev, ctrl);
+
+	if (ret)
+		msi_domain_free_locked(dev, ctrl);
+	return ret;
+}
+
+/**
+ * msi_domain_alloc_irqs_range_locked - Allocate interrupts from a MSI interrupt domain
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are allocated
+ * @domid:	Id of the interrupt domain to operate on
+ * @first:	First index to allocate (inclusive)
+ * @last:	Last index to allocate (inclusive)
+ *
+ * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
+ * pair. Use this for MSI irqdomains which implement their own descriptor
+ * allocation/free.
+ *
+ * Return: %0 on success or an error code.
+ */
+int msi_domain_alloc_irqs_range_locked(struct device *dev, unsigned int domid,
+				       unsigned int first, unsigned int last)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= domid,
+		.first	= first,
+		.last	= last,
+		.nirqs	= last + 1 - first,
+	};
+
+	return msi_domain_alloc_locked(dev, &ctrl);
+}
+
+/**
+ * msi_domain_alloc_irqs_range - Allocate interrupts from a MSI interrupt domain
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are allocated
+ * @domid:	Id of the interrupt domain to operate on
+ * @first:	First index to allocate (inclusive)
+ * @last:	Last index to allocate (inclusive)
+ *
+ * Return: %0 on success or an error code.
+ */
+int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
+				unsigned int first, unsigned int last)
+{
+	int ret;
+
+	msi_lock_descs(dev);
+	ret = msi_domain_alloc_irqs_range_locked(dev, domid, first, last);
+	msi_unlock_descs(dev);
+	return ret;
+}
+
+/**
+ * msi_domain_alloc_irqs_all_locked - Allocate all interrupts from a MSI interrupt domain
+ *
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are allocated
+ * @domid:	Id of the interrupt domain to operate on
+ * @nirqs:	The number of interrupts to allocate
+ *
+ * This function scans all MSI descriptors of the MSI domain and allocates interrupts
+ * for all unassigned ones. That function is to be used for MSI domain usage where
+ * the descriptor allocation is handled at the call site, e.g. PCI/MSI[X].
+ *
+ * Return: %0 on success or an error code.
+ */
+int msi_domain_alloc_irqs_all_locked(struct device *dev, unsigned int domid, int nirqs)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= domid,
+		.first	= 0,
+		.last	= msi_domain_get_hwsize(dev, domid) - 1,
+		.nirqs	= nirqs,
+	};
+
+	return msi_domain_alloc_locked(dev, &ctrl);
+}
+
+/**
+ * msi_domain_alloc_irq_at - Allocate an interrupt from a MSI interrupt domain at
+ *			     a given index - or at the next free index
+ *
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are allocated
+ * @domid:	Id of the interrupt domain to operate on
+ * @index:	Index for allocation. If @index == %MSI_ANY_INDEX the allocation
+ *		uses the next free index.
+ * @affdesc:	Optional pointer to an interrupt affinity descriptor structure
+ * @icookie:	Optional pointer to a domain specific per instance cookie. If
+ *		non-NULL the content of the cookie is stored in msi_desc::data.
+ *		Must be NULL for MSI-X allocations
+ *
+ * This requires a MSI interrupt domain which lets the core code manage the
+ * MSI descriptors.
+ *
+ * Return: struct msi_map
+ *
+ *	On success msi_map::index contains the allocated index number and
+ *	msi_map::virq the corresponding Linux interrupt number
+ *
+ *	On failure msi_map::index contains the error code and msi_map::virq
+ *	is %0.
+ */
+struct msi_map 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)
+{
+	struct msi_ctrl ctrl = { .domid	= domid, .nirqs = 1, };
+	struct irq_domain *domain;
+	struct msi_map map = { };
+	struct msi_desc *desc;
+	int ret;
+
+	msi_lock_descs(dev);
+	domain = msi_get_device_domain(dev, domid);
+	if (!domain) {
+		map.index = -ENODEV;
+		goto unlock;
+	}
+
+	desc = msi_alloc_desc(dev, 1, affdesc);
+	if (!desc) {
+		map.index = -ENOMEM;
+		goto unlock;
+	}
+
+	if (icookie)
+		desc->data.icookie = *icookie;
+
+	ret = msi_insert_desc(dev, desc, domid, index);
+	if (ret) {
+		map.index = ret;
+		goto unlock;
+	}
+
+	ctrl.first = ctrl.last = desc->msi_index;
+
+	ret = __msi_domain_alloc_irqs(dev, domain, &ctrl);
+	if (ret) {
+		map.index = ret;
+		msi_domain_free_locked(dev, &ctrl);
+	} else {
+		map.index = desc->msi_index;
+		map.virq = desc->irq;
+	}
+unlock:
+	msi_unlock_descs(dev);
+	return map;
+}
+
+static void __msi_domain_free_irqs(struct device *dev, struct irq_domain *domain,
+				   struct msi_ctrl *ctrl)
+{
+	struct xarray *xa = &dev->msi.data->__domains[ctrl->domid].store;
+	struct msi_domain_info *info = domain->host_data;
+	struct irq_data *irqd;
+	struct msi_desc *desc;
+	unsigned long idx;
+	int i;
+
+	xa_for_each_range(xa, idx, desc, ctrl->first, ctrl->last) {
+		/* Only handle MSI entries which have an interrupt associated */
+		if (!msi_desc_match(desc, MSI_DESC_ASSOCIATED))
+			continue;
+
+		/* Make sure all interrupts are deactivated */
+		for (i = 0; i < desc->nvec_used; i++) {
+			irqd = irq_domain_get_irq_data(domain, desc->irq + i);
+			if (irqd && irqd_is_activated(irqd))
+				irq_domain_deactivate_irq(irqd);
+		}
+
+		irq_domain_free_irqs(desc->irq, desc->nvec_used);
+		if (info->flags & MSI_FLAG_DEV_SYSFS)
+			msi_sysfs_remove_desc(dev, desc);
+		desc->irq = 0;
+	}
+}
+
+static void msi_domain_free_locked(struct device *dev, struct msi_ctrl *ctrl)
+{
+	struct msi_domain_info *info;
+	struct msi_domain_ops *ops;
+	struct irq_domain *domain;
+
+	if (!msi_ctrl_valid(dev, ctrl))
+		return;
+
+	domain = msi_get_device_domain(dev, ctrl->domid);
+	if (!domain)
+		return;
+
+	info = domain->host_data;
+	ops = info->ops;
+
+	if (ops->domain_free_irqs)
+		ops->domain_free_irqs(domain, dev);
+	else
+		__msi_domain_free_irqs(dev, domain, ctrl);
+
+	if (ops->msi_post_free)
+		ops->msi_post_free(domain, dev);
+
+	if (info->flags & MSI_FLAG_FREE_MSI_DESCS)
+		msi_domain_free_descs(dev, ctrl);
+}
+
+/**
+ * msi_domain_free_irqs_range_locked - Free a range of interrupts from a MSI interrupt domain
+ *				       associated to @dev with msi_lock held
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are freed
+ * @domid:	Id of the interrupt domain to operate on
+ * @first:	First index to free (inclusive)
+ * @last:	Last index to free (inclusive)
+ */
+void msi_domain_free_irqs_range_locked(struct device *dev, unsigned int domid,
+				       unsigned int first, unsigned int last)
+{
+	struct msi_ctrl ctrl = {
+		.domid	= domid,
+		.first	= first,
+		.last	= last,
+	};
+	msi_domain_free_locked(dev, &ctrl);
+}
+
+/**
+ * msi_domain_free_irqs_range - Free a range of interrupts from a MSI interrupt domain
+ *				associated to @dev
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are freed
+ * @domid:	Id of the interrupt domain to operate on
+ * @first:	First index to free (inclusive)
+ * @last:	Last index to free (inclusive)
+ */
+void msi_domain_free_irqs_range(struct device *dev, unsigned int domid,
+				unsigned int first, unsigned int last)
+{
+	msi_lock_descs(dev);
+	msi_domain_free_irqs_range_locked(dev, domid, first, last);
+	msi_unlock_descs(dev);
+}
+
+/**
+ * msi_domain_free_irqs_all_locked - Free all interrupts from a MSI interrupt domain
+ *				     associated to a device
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are freed
+ * @domid:	The id of the domain to operate on
+ *
+ * Must be invoked from within a msi_lock_descs() / msi_unlock_descs()
+ * pair. Use this for MSI irqdomains which implement their own vector
+ * allocation.
+ */
+void msi_domain_free_irqs_all_locked(struct device *dev, unsigned int domid)
+{
+	msi_domain_free_irqs_range_locked(dev, domid, 0,
+					  msi_domain_get_hwsize(dev, domid) - 1);
+}
+
+/**
+ * msi_domain_free_irqs_all - Free all interrupts from a MSI interrupt domain
+ *			      associated to a device
+ * @dev:	Pointer to device struct of the device for which the interrupts
+ *		are freed
+ * @domid:	The id of the domain to operate on
+ */
+void msi_domain_free_irqs_all(struct device *dev, unsigned int domid)
+{
+	msi_lock_descs(dev);
+	msi_domain_free_irqs_all_locked(dev, domid);
+	msi_unlock_descs(dev);
+}
+
+/**
+ * msi_get_domain_info - Get the MSI interrupt domain info for @domain
+ * @domain:	The interrupt domain to retrieve data from
+ *
+ * Return: the pointer to the msi_domain_info stored in @domain->host_data.
+ */
+struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain)
+{
+	return (struct msi_domain_info *)domain->host_data;
+}
+
+/**
+ * msi_device_has_isolated_msi - True if the device has isolated MSI
+ * @dev: The device to check
+ *
+ * Isolated MSI means that HW modeled by an irq_domain on the path from the
+ * initiating device to the CPU will validate that the MSI message specifies an
+ * interrupt number that the device is authorized to trigger. This must block
+ * devices from triggering interrupts they are not authorized to trigger.
+ * Currently authorization means the MSI vector is one assigned to the device.
+ *
+ * This is interesting for securing VFIO use cases where a rouge MSI (eg created
+ * by abusing a normal PCI MemWr DMA) must not allow the VFIO userspace to
+ * impact outside its security domain, eg userspace triggering interrupts on
+ * kernel drivers, a VM triggering interrupts on the hypervisor, or a VM
+ * triggering interrupts on another VM.
+ */
+bool msi_device_has_isolated_msi(struct device *dev)
+{
+	struct irq_domain *domain = dev_get_msi_domain(dev);
+
+	for (; domain; domain = domain->parent)
+		if (domain->flags & IRQ_DOMAIN_FLAG_ISOLATED_MSI)
+			return true;
+	return arch_is_isolated_msi();
+}
+EXPORT_SYMBOL_GPL(msi_device_has_isolated_msi);