Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 1770 insertions, 0 deletions

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
new file mode 100644
index 000000000..1e42fc2ad
--- /dev/null
+++ b/kernel/irq/irqdomain.c
@@ -0,0 +1,1770 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt)  "irq: " fmt
+
+#include <linux/acpi.h>
+#include <linux/debugfs.h>
+#include <linux/hardirq.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/topology.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/fs.h>
+
+static LIST_HEAD(irq_domain_list);
+static DEFINE_MUTEX(irq_domain_mutex);
+
+static struct irq_domain *irq_default_domain;
+
+static void irq_domain_check_hierarchy(struct irq_domain *domain);
+
+struct irqchip_fwid {
+	struct fwnode_handle	fwnode;
+	unsigned int		type;
+	char			*name;
+	void *data;
+};
+
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+static void debugfs_add_domain_dir(struct irq_domain *d);
+static void debugfs_remove_domain_dir(struct irq_domain *d);
+#else
+static inline void debugfs_add_domain_dir(struct irq_domain *d) { }
+static inline void debugfs_remove_domain_dir(struct irq_domain *d) { }
+#endif
+
+const struct fwnode_operations irqchip_fwnode_ops;
+EXPORT_SYMBOL_GPL(irqchip_fwnode_ops);
+
+/**
+ * irq_domain_alloc_fwnode - Allocate a fwnode_handle suitable for
+ *                           identifying an irq domain
+ * @type:	Type of irqchip_fwnode. See linux/irqdomain.h
+ * @name:	Optional user provided domain name
+ * @id:		Optional user provided id if name != NULL
+ * @data:	Optional user-provided data
+ *
+ * Allocate a struct irqchip_fwid, and return a poiner to the embedded
+ * fwnode_handle (or NULL on failure).
+ *
+ * Note: The types IRQCHIP_FWNODE_NAMED and IRQCHIP_FWNODE_NAMED_ID are
+ * solely to transport name information to irqdomain creation code. The
+ * node is not stored. For other types the pointer is kept in the irq
+ * domain struct.
+ */
+struct fwnode_handle *__irq_domain_alloc_fwnode(unsigned int type, int id,
+						const char *name, void *data)
+{
+	struct irqchip_fwid *fwid;
+	char *n;
+
+	fwid = kzalloc(sizeof(*fwid), GFP_KERNEL);
+
+	switch (type) {
+	case IRQCHIP_FWNODE_NAMED:
+		n = kasprintf(GFP_KERNEL, "%s", name);
+		break;
+	case IRQCHIP_FWNODE_NAMED_ID:
+		n = kasprintf(GFP_KERNEL, "%s-%d", name, id);
+		break;
+	default:
+		n = kasprintf(GFP_KERNEL, "irqchip@%p", data);
+		break;
+	}
+
+	if (!fwid || !n) {
+		kfree(fwid);
+		kfree(n);
+		return NULL;
+	}
+
+	fwid->type = type;
+	fwid->name = n;
+	fwid->data = data;
+	fwid->fwnode.ops = &irqchip_fwnode_ops;
+	return &fwid->fwnode;
+}
+EXPORT_SYMBOL_GPL(__irq_domain_alloc_fwnode);
+
+/**
+ * irq_domain_free_fwnode - Free a non-OF-backed fwnode_handle
+ *
+ * Free a fwnode_handle allocated with irq_domain_alloc_fwnode.
+ */
+void irq_domain_free_fwnode(struct fwnode_handle *fwnode)
+{
+	struct irqchip_fwid *fwid;
+
+	if (WARN_ON(!is_fwnode_irqchip(fwnode)))
+		return;
+
+	fwid = container_of(fwnode, struct irqchip_fwid, fwnode);
+	kfree(fwid->name);
+	kfree(fwid);
+}
+EXPORT_SYMBOL_GPL(irq_domain_free_fwnode);
+
+/**
+ * __irq_domain_add() - Allocate a new irq_domain data structure
+ * @fwnode: firmware node for the interrupt controller
+ * @size: Size of linear map; 0 for radix mapping only
+ * @hwirq_max: Maximum number of interrupts supported by controller
+ * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
+ *              direct mapping
+ * @ops: domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Allocates and initialize and irq_domain structure.
+ * Returns pointer to IRQ domain, or NULL on failure.
+ */
+struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
+				    irq_hw_number_t hwirq_max, int direct_max,
+				    const struct irq_domain_ops *ops,
+				    void *host_data)
+{
+	struct device_node *of_node = to_of_node(fwnode);
+	struct irqchip_fwid *fwid;
+	struct irq_domain *domain;
+
+	static atomic_t unknown_domains;
+
+	domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
+			      GFP_KERNEL, of_node_to_nid(of_node));
+	if (WARN_ON(!domain))
+		return NULL;
+
+	if (fwnode && is_fwnode_irqchip(fwnode)) {
+		fwid = container_of(fwnode, struct irqchip_fwid, fwnode);
+
+		switch (fwid->type) {
+		case IRQCHIP_FWNODE_NAMED:
+		case IRQCHIP_FWNODE_NAMED_ID:
+			domain->fwnode = fwnode;
+			domain->name = kstrdup(fwid->name, GFP_KERNEL);
+			if (!domain->name) {
+				kfree(domain);
+				return NULL;
+			}
+			domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
+			break;
+		default:
+			domain->fwnode = fwnode;
+			domain->name = fwid->name;
+			break;
+		}
+#ifdef CONFIG_ACPI
+	} else if (is_acpi_device_node(fwnode)) {
+		struct acpi_buffer buf = {
+			.length = ACPI_ALLOCATE_BUFFER,
+		};
+		acpi_handle handle;
+
+		handle = acpi_device_handle(to_acpi_device_node(fwnode));
+		if (acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf) == AE_OK) {
+			domain->name = buf.pointer;
+			domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
+		}
+
+		domain->fwnode = fwnode;
+#endif
+	} else if (of_node) {
+		char *name;
+
+		/*
+		 * DT paths contain '/', which debugfs is legitimately
+		 * unhappy about. Replace them with ':', which does
+		 * the trick and is not as offensive as '\'...
+		 */
+		name = kasprintf(GFP_KERNEL, "%pOF", of_node);
+		if (!name) {
+			kfree(domain);
+			return NULL;
+		}
+
+		strreplace(name, '/', ':');
+
+		domain->name = name;
+		domain->fwnode = fwnode;
+		domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
+	}
+
+	if (!domain->name) {
+		if (fwnode)
+			pr_err("Invalid fwnode type for irqdomain\n");
+		domain->name = kasprintf(GFP_KERNEL, "unknown-%d",
+					 atomic_inc_return(&unknown_domains));
+		if (!domain->name) {
+			kfree(domain);
+			return NULL;
+		}
+		domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
+	}
+
+	of_node_get(of_node);
+
+	/* Fill structure */
+	INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
+	mutex_init(&domain->revmap_tree_mutex);
+	domain->ops = ops;
+	domain->host_data = host_data;
+	domain->hwirq_max = hwirq_max;
+	domain->revmap_size = size;
+	domain->revmap_direct_max_irq = direct_max;
+	irq_domain_check_hierarchy(domain);
+
+	mutex_lock(&irq_domain_mutex);
+	debugfs_add_domain_dir(domain);
+	list_add(&domain->link, &irq_domain_list);
+	mutex_unlock(&irq_domain_mutex);
+
+	pr_debug("Added domain %s\n", domain->name);
+	return domain;
+}
+EXPORT_SYMBOL_GPL(__irq_domain_add);
+
+/**
+ * irq_domain_remove() - Remove an irq domain.
+ * @domain: domain to remove
+ *
+ * This routine is used to remove an irq domain. The caller must ensure
+ * that all mappings within the domain have been disposed of prior to
+ * use, depending on the revmap type.
+ */
+void irq_domain_remove(struct irq_domain *domain)
+{
+	mutex_lock(&irq_domain_mutex);
+	debugfs_remove_domain_dir(domain);
+
+	WARN_ON(!radix_tree_empty(&domain->revmap_tree));
+
+	list_del(&domain->link);
+
+	/*
+	 * If the going away domain is the default one, reset it.
+	 */
+	if (unlikely(irq_default_domain == domain))
+		irq_set_default_host(NULL);
+
+	mutex_unlock(&irq_domain_mutex);
+
+	pr_debug("Removed domain %s\n", domain->name);
+
+	of_node_put(irq_domain_get_of_node(domain));
+	if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
+		kfree(domain->name);
+	kfree(domain);
+}
+EXPORT_SYMBOL_GPL(irq_domain_remove);
+
+void irq_domain_update_bus_token(struct irq_domain *domain,
+				 enum irq_domain_bus_token bus_token)
+{
+	char *name;
+
+	if (domain->bus_token == bus_token)
+		return;
+
+	mutex_lock(&irq_domain_mutex);
+
+	domain->bus_token = bus_token;
+
+	name = kasprintf(GFP_KERNEL, "%s-%d", domain->name, bus_token);
+	if (!name) {
+		mutex_unlock(&irq_domain_mutex);
+		return;
+	}
+
+	debugfs_remove_domain_dir(domain);
+
+	if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
+		kfree(domain->name);
+	else
+		domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
+
+	domain->name = name;
+	debugfs_add_domain_dir(domain);
+
+	mutex_unlock(&irq_domain_mutex);
+}
+
+/**
+ * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @size: total number of irqs in mapping
+ * @first_irq: first number of irq block assigned to the domain,
+ *	pass zero to assign irqs on-the-fly. If first_irq is non-zero, then
+ *	pre-map all of the irqs in the domain to virqs starting at first_irq.
+ * @ops: domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Allocates an irq_domain, and optionally if first_irq is positive then also
+ * allocate irq_descs and map all of the hwirqs to virqs starting at first_irq.
+ *
+ * This is intended to implement the expected behaviour for most
+ * interrupt controllers. If device tree is used, then first_irq will be 0 and
+ * irqs get mapped dynamically on the fly. However, if the controller requires
+ * static virq assignments (non-DT boot) then it will set that up correctly.
+ */
+struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
+					 unsigned int size,
+					 unsigned int first_irq,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain;
+
+	domain = __irq_domain_add(of_node_to_fwnode(of_node), size, size, 0, ops, host_data);
+	if (!domain)
+		return NULL;
+
+	if (first_irq > 0) {
+		if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
+			/* attempt to allocated irq_descs */
+			int rc = irq_alloc_descs(first_irq, first_irq, size,
+						 of_node_to_nid(of_node));
+			if (rc < 0)
+				pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
+					first_irq);
+		}
+		irq_domain_associate_many(domain, first_irq, 0, size);
+	}
+
+	return domain;
+}
+EXPORT_SYMBOL_GPL(irq_domain_add_simple);
+
+/**
+ * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @size: total number of irqs in legacy mapping
+ * @first_irq: first number of irq block assigned to the domain
+ * @first_hwirq: first hwirq number to use for the translation. Should normally
+ *               be '0', but a positive integer can be used if the effective
+ *               hwirqs numbering does not begin at zero.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Note: the map() callback will be called before this function returns
+ * for all legacy interrupts except 0 (which is always the invalid irq for
+ * a legacy controller).
+ */
+struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
+					 unsigned int size,
+					 unsigned int first_irq,
+					 irq_hw_number_t first_hwirq,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain;
+
+	domain = __irq_domain_add(of_node_to_fwnode(of_node), first_hwirq + size,
+				  first_hwirq + size, 0, ops, host_data);
+	if (domain)
+		irq_domain_associate_many(domain, first_irq, first_hwirq, size);
+
+	return domain;
+}
+EXPORT_SYMBOL_GPL(irq_domain_add_legacy);
+
+/**
+ * irq_find_matching_fwspec() - Locates a domain for a given fwspec
+ * @fwspec: FW specifier for an interrupt
+ * @bus_token: domain-specific data
+ */
+struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec,
+					    enum irq_domain_bus_token bus_token)
+{
+	struct irq_domain *h, *found = NULL;
+	struct fwnode_handle *fwnode = fwspec->fwnode;
+	int rc;
+
+	/* We might want to match the legacy controller last since
+	 * it might potentially be set to match all interrupts in
+	 * the absence of a device node. This isn't a problem so far
+	 * yet though...
+	 *
+	 * bus_token == DOMAIN_BUS_ANY matches any domain, any other
+	 * values must generate an exact match for the domain to be
+	 * selected.
+	 */
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(h, &irq_domain_list, link) {
+		if (h->ops->select && fwspec->param_count)
+			rc = h->ops->select(h, fwspec, bus_token);
+		else if (h->ops->match)
+			rc = h->ops->match(h, to_of_node(fwnode), bus_token);
+		else
+			rc = ((fwnode != NULL) && (h->fwnode == fwnode) &&
+			      ((bus_token == DOMAIN_BUS_ANY) ||
+			       (h->bus_token == bus_token)));
+
+		if (rc) {
+			found = h;
+			break;
+		}
+	}
+	mutex_unlock(&irq_domain_mutex);
+	return found;
+}
+EXPORT_SYMBOL_GPL(irq_find_matching_fwspec);
+
+/**
+ * irq_domain_check_msi_remap - Check whether all MSI irq domains implement
+ * IRQ remapping
+ *
+ * Return: false if any MSI irq domain does not support IRQ remapping,
+ * true otherwise (including if there is no MSI irq domain)
+ */
+bool irq_domain_check_msi_remap(void)
+{
+	struct irq_domain *h;
+	bool ret = true;
+
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(h, &irq_domain_list, link) {
+		if (irq_domain_is_msi(h) &&
+		    !irq_domain_hierarchical_is_msi_remap(h)) {
+			ret = false;
+			break;
+		}
+	}
+	mutex_unlock(&irq_domain_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(irq_domain_check_msi_remap);
+
+/**
+ * irq_set_default_host() - Set a "default" irq domain
+ * @domain: default domain pointer
+ *
+ * For convenience, it's possible to set a "default" domain that will be used
+ * whenever NULL is passed to irq_create_mapping(). It makes life easier for
+ * platforms that want to manipulate a few hard coded interrupt numbers that
+ * aren't properly represented in the device-tree.
+ */
+void irq_set_default_host(struct irq_domain *domain)
+{
+	pr_debug("Default domain set to @0x%p\n", domain);
+
+	irq_default_domain = domain;
+}
+EXPORT_SYMBOL_GPL(irq_set_default_host);
+
+static void irq_domain_clear_mapping(struct irq_domain *domain,
+				     irq_hw_number_t hwirq)
+{
+	if (hwirq < domain->revmap_size) {
+		domain->linear_revmap[hwirq] = 0;
+	} else {
+		mutex_lock(&domain->revmap_tree_mutex);
+		radix_tree_delete(&domain->revmap_tree, hwirq);
+		mutex_unlock(&domain->revmap_tree_mutex);
+	}
+}
+
+static void irq_domain_set_mapping(struct irq_domain *domain,
+				   irq_hw_number_t hwirq,
+				   struct irq_data *irq_data)
+{
+	if (hwirq < domain->revmap_size) {
+		domain->linear_revmap[hwirq] = irq_data->irq;
+	} else {
+		mutex_lock(&domain->revmap_tree_mutex);
+		radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
+		mutex_unlock(&domain->revmap_tree_mutex);
+	}
+}
+
+void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(irq);
+	irq_hw_number_t hwirq;
+
+	if (WARN(!irq_data || irq_data->domain != domain,
+		 "virq%i doesn't exist; cannot disassociate\n", irq))
+		return;
+
+	hwirq = irq_data->hwirq;
+	irq_set_status_flags(irq, IRQ_NOREQUEST);
+
+	/* remove chip and handler */
+	irq_set_chip_and_handler(irq, NULL, NULL);
+
+	/* Make sure it's completed */
+	synchronize_irq(irq);
+
+	/* Tell the PIC about it */
+	if (domain->ops->unmap)
+		domain->ops->unmap(domain, irq);
+	smp_mb();
+
+	irq_data->domain = NULL;
+	irq_data->hwirq = 0;
+	domain->mapcount--;
+
+	/* Clear reverse map for this hwirq */
+	irq_domain_clear_mapping(domain, hwirq);
+}
+
+int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
+			 irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	int ret;
+
+	if (WARN(hwirq >= domain->hwirq_max,
+		 "error: hwirq 0x%x is too large for %s\n", (int)hwirq, domain->name))
+		return -EINVAL;
+	if (WARN(!irq_data, "error: virq%i is not allocated", virq))
+		return -EINVAL;
+	if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
+		return -EINVAL;
+
+	mutex_lock(&irq_domain_mutex);
+	irq_data->hwirq = hwirq;
+	irq_data->domain = domain;
+	if (domain->ops->map) {
+		ret = domain->ops->map(domain, virq, hwirq);
+		if (ret != 0) {
+			/*
+			 * If map() returns -EPERM, this interrupt is protected
+			 * by the firmware or some other service and shall not
+			 * be mapped. Don't bother telling the user about it.
+			 */
+			if (ret != -EPERM) {
+				pr_info("%s didn't like hwirq-0x%lx to VIRQ%i mapping (rc=%d)\n",
+				       domain->name, hwirq, virq, ret);
+			}
+			irq_data->domain = NULL;
+			irq_data->hwirq = 0;
+			mutex_unlock(&irq_domain_mutex);
+			return ret;
+		}
+
+		/* If not already assigned, give the domain the chip's name */
+		if (!domain->name && irq_data->chip)
+			domain->name = irq_data->chip->name;
+	}
+
+	domain->mapcount++;
+	irq_domain_set_mapping(domain, hwirq, irq_data);
+	mutex_unlock(&irq_domain_mutex);
+
+	irq_clear_status_flags(virq, IRQ_NOREQUEST);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_associate);
+
+void irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
+			       irq_hw_number_t hwirq_base, int count)
+{
+	struct device_node *of_node;
+	int i;
+
+	of_node = irq_domain_get_of_node(domain);
+	pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
+		of_node_full_name(of_node), irq_base, (int)hwirq_base, count);
+
+	for (i = 0; i < count; i++) {
+		irq_domain_associate(domain, irq_base + i, hwirq_base + i);
+	}
+}
+EXPORT_SYMBOL_GPL(irq_domain_associate_many);
+
+/**
+ * irq_create_direct_mapping() - Allocate an irq for direct mapping
+ * @domain: domain to allocate the irq for or NULL for default domain
+ *
+ * This routine is used for irq controllers which can choose the hardware
+ * interrupt numbers they generate. In such a case it's simplest to use
+ * the linux irq as the hardware interrupt number. It still uses the linear
+ * or radix tree to store the mapping, but the irq controller can optimize
+ * the revmap path by using the hwirq directly.
+ */
+unsigned int irq_create_direct_mapping(struct irq_domain *domain)
+{
+	struct device_node *of_node;
+	unsigned int virq;
+
+	if (domain == NULL)
+		domain = irq_default_domain;
+
+	of_node = irq_domain_get_of_node(domain);
+	virq = irq_alloc_desc_from(1, of_node_to_nid(of_node));
+	if (!virq) {
+		pr_debug("create_direct virq allocation failed\n");
+		return 0;
+	}
+	if (virq >= domain->revmap_direct_max_irq) {
+		pr_err("ERROR: no free irqs available below %i maximum\n",
+			domain->revmap_direct_max_irq);
+		irq_free_desc(virq);
+		return 0;
+	}
+	pr_debug("create_direct obtained virq %d\n", virq);
+
+	if (irq_domain_associate(domain, virq, virq)) {
+		irq_free_desc(virq);
+		return 0;
+	}
+
+	return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
+
+/**
+ * irq_create_mapping() - Map a hardware interrupt into linux irq space
+ * @domain: domain owning this hardware interrupt or NULL for default domain
+ * @hwirq: hardware irq number in that domain space
+ *
+ * Only one mapping per hardware interrupt is permitted. Returns a linux
+ * irq number.
+ * If the sense/trigger is to be specified, set_irq_type() should be called
+ * on the number returned from that call.
+ */
+unsigned int irq_create_mapping(struct irq_domain *domain,
+				irq_hw_number_t hwirq)
+{
+	struct device_node *of_node;
+	int virq;
+
+	pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
+
+	/* Look for default domain if nececssary */
+	if (domain == NULL)
+		domain = irq_default_domain;
+	if (domain == NULL) {
+		WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
+		return 0;
+	}
+	pr_debug("-> using domain @%p\n", domain);
+
+	of_node = irq_domain_get_of_node(domain);
+
+	/* Check if mapping already exists */
+	virq = irq_find_mapping(domain, hwirq);
+	if (virq) {
+		pr_debug("-> existing mapping on virq %d\n", virq);
+		return virq;
+	}
+
+	/* Allocate a virtual interrupt number */
+	virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), NULL);
+	if (virq <= 0) {
+		pr_debug("-> virq allocation failed\n");
+		return 0;
+	}
+
+	if (irq_domain_associate(domain, virq, hwirq)) {
+		irq_free_desc(virq);
+		return 0;
+	}
+
+	pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
+		hwirq, of_node_full_name(of_node), virq);
+
+	return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_mapping);
+
+/**
+ * irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs
+ * @domain: domain owning the interrupt range
+ * @irq_base: beginning of linux IRQ range
+ * @hwirq_base: beginning of hardware IRQ range
+ * @count: Number of interrupts to map
+ *
+ * This routine is used for allocating and mapping a range of hardware
+ * irqs to linux irqs where the linux irq numbers are at pre-defined
+ * locations. For use by controllers that already have static mappings
+ * to insert in to the domain.
+ *
+ * Non-linear users can use irq_create_identity_mapping() for IRQ-at-a-time
+ * domain insertion.
+ *
+ * 0 is returned upon success, while any failure to establish a static
+ * mapping is treated as an error.
+ */
+int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
+			       irq_hw_number_t hwirq_base, int count)
+{
+	struct device_node *of_node;
+	int ret;
+
+	of_node = irq_domain_get_of_node(domain);
+	ret = irq_alloc_descs(irq_base, irq_base, count,
+			      of_node_to_nid(of_node));
+	if (unlikely(ret < 0))
+		return ret;
+
+	irq_domain_associate_many(domain, irq_base, hwirq_base, count);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_create_strict_mappings);
+
+static int irq_domain_translate(struct irq_domain *d,
+				struct irq_fwspec *fwspec,
+				irq_hw_number_t *hwirq, unsigned int *type)
+{
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+	if (d->ops->translate)
+		return d->ops->translate(d, fwspec, hwirq, type);
+#endif
+	if (d->ops->xlate)
+		return d->ops->xlate(d, to_of_node(fwspec->fwnode),
+				     fwspec->param, fwspec->param_count,
+				     hwirq, type);
+
+	/* If domain has no translation, then we assume interrupt line */
+	*hwirq = fwspec->param[0];
+	return 0;
+}
+
+static void of_phandle_args_to_fwspec(struct of_phandle_args *irq_data,
+				      struct irq_fwspec *fwspec)
+{
+	int i;
+
+	fwspec->fwnode = irq_data->np ? &irq_data->np->fwnode : NULL;
+	fwspec->param_count = irq_data->args_count;
+
+	for (i = 0; i < irq_data->args_count; i++)
+		fwspec->param[i] = irq_data->args[i];
+}
+
+unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
+{
+	struct irq_domain *domain;
+	struct irq_data *irq_data;
+	irq_hw_number_t hwirq;
+	unsigned int type = IRQ_TYPE_NONE;
+	int virq;
+
+	if (fwspec->fwnode) {
+		domain = irq_find_matching_fwspec(fwspec, DOMAIN_BUS_WIRED);
+		if (!domain)
+			domain = irq_find_matching_fwspec(fwspec, DOMAIN_BUS_ANY);
+	} else {
+		domain = irq_default_domain;
+	}
+
+	if (!domain) {
+		pr_warn("no irq domain found for %s !\n",
+			of_node_full_name(to_of_node(fwspec->fwnode)));
+		return 0;
+	}
+
+	if (irq_domain_translate(domain, fwspec, &hwirq, &type))
+		return 0;
+
+	/*
+	 * WARN if the irqchip returns a type with bits
+	 * outside the sense mask set and clear these bits.
+	 */
+	if (WARN_ON(type & ~IRQ_TYPE_SENSE_MASK))
+		type &= IRQ_TYPE_SENSE_MASK;
+
+	/*
+	 * If we've already configured this interrupt,
+	 * don't do it again, or hell will break loose.
+	 */
+	virq = irq_find_mapping(domain, hwirq);
+	if (virq) {
+		/*
+		 * If the trigger type is not specified or matches the
+		 * current trigger type then we are done so return the
+		 * interrupt number.
+		 */
+		if (type == IRQ_TYPE_NONE || type == irq_get_trigger_type(virq))
+			return virq;
+
+		/*
+		 * If the trigger type has not been set yet, then set
+		 * it now and return the interrupt number.
+		 */
+		if (irq_get_trigger_type(virq) == IRQ_TYPE_NONE) {
+			irq_data = irq_get_irq_data(virq);
+			if (!irq_data)
+				return 0;
+
+			irqd_set_trigger_type(irq_data, type);
+			return virq;
+		}
+
+		pr_warn("type mismatch, failed to map hwirq-%lu for %s!\n",
+			hwirq, of_node_full_name(to_of_node(fwspec->fwnode)));
+		return 0;
+	}
+
+	if (irq_domain_is_hierarchy(domain)) {
+		virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, fwspec);
+		if (virq <= 0)
+			return 0;
+	} else {
+		/* Create mapping */
+		virq = irq_create_mapping(domain, hwirq);
+		if (!virq)
+			return virq;
+	}
+
+	irq_data = irq_get_irq_data(virq);
+	if (!irq_data) {
+		if (irq_domain_is_hierarchy(domain))
+			irq_domain_free_irqs(virq, 1);
+		else
+			irq_dispose_mapping(virq);
+		return 0;
+	}
+
+	/* Store trigger type */
+	irqd_set_trigger_type(irq_data, type);
+
+	return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_fwspec_mapping);
+
+unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
+{
+	struct irq_fwspec fwspec;
+
+	of_phandle_args_to_fwspec(irq_data, &fwspec);
+	return irq_create_fwspec_mapping(&fwspec);
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+/**
+ * irq_dispose_mapping() - Unmap an interrupt
+ * @virq: linux irq number of the interrupt to unmap
+ */
+void irq_dispose_mapping(unsigned int virq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	struct irq_domain *domain;
+
+	if (!virq || !irq_data)
+		return;
+
+	domain = irq_data->domain;
+	if (WARN_ON(domain == NULL))
+		return;
+
+	if (irq_domain_is_hierarchy(domain)) {
+		irq_domain_free_irqs(virq, 1);
+	} else {
+		irq_domain_disassociate(domain, virq);
+		irq_free_desc(virq);
+	}
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+
+/**
+ * irq_find_mapping() - Find a linux irq from an hw irq number.
+ * @domain: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that domain space
+ */
+unsigned int irq_find_mapping(struct irq_domain *domain,
+			      irq_hw_number_t hwirq)
+{
+	struct irq_data *data;
+
+	/* Look for default domain if nececssary */
+	if (domain == NULL)
+		domain = irq_default_domain;
+	if (domain == NULL)
+		return 0;
+
+	if (hwirq < domain->revmap_direct_max_irq) {
+		data = irq_domain_get_irq_data(domain, hwirq);
+		if (data && data->hwirq == hwirq)
+			return hwirq;
+	}
+
+	/* Check if the hwirq is in the linear revmap. */
+	if (hwirq < domain->revmap_size)
+		return domain->linear_revmap[hwirq];
+
+	rcu_read_lock();
+	data = radix_tree_lookup(&domain->revmap_tree, hwirq);
+	rcu_read_unlock();
+	return data ? data->irq : 0;
+}
+EXPORT_SYMBOL_GPL(irq_find_mapping);
+
+/**
+ * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings
+ *
+ * Device Tree IRQ specifier translation function which works with one cell
+ * bindings where the cell value maps directly to the hwirq number.
+ */
+int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
+			     const u32 *intspec, unsigned int intsize,
+			     unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = intspec[0];
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_onecell);
+
+/**
+ * irq_domain_xlate_twocell() - Generic xlate for direct two cell bindings
+ *
+ * Device Tree IRQ specifier translation function which works with two cell
+ * bindings where the cell values map directly to the hwirq number
+ * and linux irq flags.
+ */
+int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 2))
+		return -EINVAL;
+	*out_hwirq = intspec[0];
+	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);
+
+/**
+ * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
+ *
+ * Device Tree IRQ specifier translation function which works with either one
+ * or two cell bindings where the cell values map directly to the hwirq number
+ * and linux irq flags.
+ *
+ * Note: don't use this function unless your interrupt controller explicitly
+ * supports both one and two cell bindings.  For the majority of controllers
+ * the _onecell() or _twocell() variants above should be used.
+ */
+int irq_domain_xlate_onetwocell(struct irq_domain *d,
+				struct device_node *ctrlr,
+				const u32 *intspec, unsigned int intsize,
+				unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = intspec[0];
+	if (intsize > 1)
+		*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
+	else
+		*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);
+
+const struct irq_domain_ops irq_domain_simple_ops = {
+	.xlate = irq_domain_xlate_onetwocell,
+};
+EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
+
+int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
+			   int node, const struct cpumask *affinity)
+{
+	unsigned int hint;
+
+	if (virq >= 0) {
+		virq = __irq_alloc_descs(virq, virq, cnt, node, THIS_MODULE,
+					 affinity);
+	} else {
+		hint = hwirq % nr_irqs;
+		if (hint == 0)
+			hint++;
+		virq = __irq_alloc_descs(-1, hint, cnt, node, THIS_MODULE,
+					 affinity);
+		if (virq <= 0 && hint > 1) {
+			virq = __irq_alloc_descs(-1, 1, cnt, node, THIS_MODULE,
+						 affinity);
+		}
+	}
+
+	return virq;
+}
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+/**
+ * irq_domain_create_hierarchy - Add a irqdomain into the hierarchy
+ * @parent:	Parent irq domain to associate with the new domain
+ * @flags:	Irq domain flags associated to the domain
+ * @size:	Size of the domain. See below
+ * @fwnode:	Optional fwnode of the interrupt controller
+ * @ops:	Pointer to the interrupt domain callbacks
+ * @host_data:	Controller private data pointer
+ *
+ * If @size is 0 a tree domain is created, otherwise a linear domain.
+ *
+ * If successful the parent is associated to the new domain and the
+ * domain flags are set.
+ * Returns pointer to IRQ domain, or NULL on failure.
+ */
+struct irq_domain *irq_domain_create_hierarchy(struct irq_domain *parent,
+					    unsigned int flags,
+					    unsigned int size,
+					    struct fwnode_handle *fwnode,
+					    const struct irq_domain_ops *ops,
+					    void *host_data)
+{
+	struct irq_domain *domain;
+
+	if (size)
+		domain = irq_domain_create_linear(fwnode, size, ops, host_data);
+	else
+		domain = irq_domain_create_tree(fwnode, ops, host_data);
+	if (domain) {
+		domain->parent = parent;
+		domain->flags |= flags;
+	}
+
+	return domain;
+}
+EXPORT_SYMBOL_GPL(irq_domain_create_hierarchy);
+
+static void irq_domain_insert_irq(int virq)
+{
+	struct irq_data *data;
+
+	for (data = irq_get_irq_data(virq); data; data = data->parent_data) {
+		struct irq_domain *domain = data->domain;
+
+		domain->mapcount++;
+		irq_domain_set_mapping(domain, data->hwirq, data);
+
+		/* If not already assigned, give the domain the chip's name */
+		if (!domain->name && data->chip)
+			domain->name = data->chip->name;
+	}
+
+	irq_clear_status_flags(virq, IRQ_NOREQUEST);
+}
+
+static void irq_domain_remove_irq(int virq)
+{
+	struct irq_data *data;
+
+	irq_set_status_flags(virq, IRQ_NOREQUEST);
+	irq_set_chip_and_handler(virq, NULL, NULL);
+	synchronize_irq(virq);
+	smp_mb();
+
+	for (data = irq_get_irq_data(virq); data; data = data->parent_data) {
+		struct irq_domain *domain = data->domain;
+		irq_hw_number_t hwirq = data->hwirq;
+
+		domain->mapcount--;
+		irq_domain_clear_mapping(domain, hwirq);
+	}
+}
+
+static struct irq_data *irq_domain_insert_irq_data(struct irq_domain *domain,
+						   struct irq_data *child)
+{
+	struct irq_data *irq_data;
+
+	irq_data = kzalloc_node(sizeof(*irq_data), GFP_KERNEL,
+				irq_data_get_node(child));
+	if (irq_data) {
+		child->parent_data = irq_data;
+		irq_data->irq = child->irq;
+		irq_data->common = child->common;
+		irq_data->domain = domain;
+	}
+
+	return irq_data;
+}
+
+static void irq_domain_free_irq_data(unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *irq_data, *tmp;
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_data = irq_get_irq_data(virq + i);
+		tmp = irq_data->parent_data;
+		irq_data->parent_data = NULL;
+		irq_data->domain = NULL;
+
+		while (tmp) {
+			irq_data = tmp;
+			tmp = tmp->parent_data;
+			kfree(irq_data);
+		}
+	}
+}
+
+static int irq_domain_alloc_irq_data(struct irq_domain *domain,
+				     unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *irq_data;
+	struct irq_domain *parent;
+	int i;
+
+	/* The outermost irq_data is embedded in struct irq_desc */
+	for (i = 0; i < nr_irqs; i++) {
+		irq_data = irq_get_irq_data(virq + i);
+		irq_data->domain = domain;
+
+		for (parent = domain->parent; parent; parent = parent->parent) {
+			irq_data = irq_domain_insert_irq_data(parent, irq_data);
+			if (!irq_data) {
+				irq_domain_free_irq_data(virq, i + 1);
+				return -ENOMEM;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * irq_domain_get_irq_data - Get irq_data associated with @virq and @domain
+ * @domain:	domain to match
+ * @virq:	IRQ number to get irq_data
+ */
+struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain,
+					 unsigned int virq)
+{
+	struct irq_data *irq_data;
+
+	for (irq_data = irq_get_irq_data(virq); irq_data;
+	     irq_data = irq_data->parent_data)
+		if (irq_data->domain == domain)
+			return irq_data;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(irq_domain_get_irq_data);
+
+/**
+ * irq_domain_set_hwirq_and_chip - Set hwirq and irqchip of @virq at @domain
+ * @domain:	Interrupt domain to match
+ * @virq:	IRQ number
+ * @hwirq:	The hwirq number
+ * @chip:	The associated interrupt chip
+ * @chip_data:	The associated chip data
+ */
+int irq_domain_set_hwirq_and_chip(struct irq_domain *domain, unsigned int virq,
+				  irq_hw_number_t hwirq, struct irq_chip *chip,
+				  void *chip_data)
+{
+	struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
+
+	if (!irq_data)
+		return -ENOENT;
+
+	irq_data->hwirq = hwirq;
+	irq_data->chip = chip ? chip : &no_irq_chip;
+	irq_data->chip_data = chip_data;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_set_hwirq_and_chip);
+
+/**
+ * irq_domain_set_info - Set the complete data for a @virq in @domain
+ * @domain:		Interrupt domain to match
+ * @virq:		IRQ number
+ * @hwirq:		The hardware interrupt number
+ * @chip:		The associated interrupt chip
+ * @chip_data:		The associated interrupt chip data
+ * @handler:		The interrupt flow handler
+ * @handler_data:	The interrupt flow handler data
+ * @handler_name:	The interrupt handler name
+ */
+void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
+			 irq_hw_number_t hwirq, struct irq_chip *chip,
+			 void *chip_data, irq_flow_handler_t handler,
+			 void *handler_data, const char *handler_name)
+{
+	irq_domain_set_hwirq_and_chip(domain, virq, hwirq, chip, chip_data);
+	__irq_set_handler(virq, handler, 0, handler_name);
+	irq_set_handler_data(virq, handler_data);
+}
+EXPORT_SYMBOL(irq_domain_set_info);
+
+/**
+ * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
+ * @irq_data:	The pointer to irq_data
+ */
+void irq_domain_reset_irq_data(struct irq_data *irq_data)
+{
+	irq_data->hwirq = 0;
+	irq_data->chip = &no_irq_chip;
+	irq_data->chip_data = NULL;
+}
+EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);
+
+/**
+ * irq_domain_free_irqs_common - Clear irq_data and free the parent
+ * @domain:	Interrupt domain to match
+ * @virq:	IRQ number to start with
+ * @nr_irqs:	The number of irqs to free
+ */
+void irq_domain_free_irqs_common(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs)
+{
+	struct irq_data *irq_data;
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_data = irq_domain_get_irq_data(domain, virq + i);
+		if (irq_data)
+			irq_domain_reset_irq_data(irq_data);
+	}
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+EXPORT_SYMBOL_GPL(irq_domain_free_irqs_common);
+
+/**
+ * irq_domain_free_irqs_top - Clear handler and handler data, clear irqdata and free parent
+ * @domain:	Interrupt domain to match
+ * @virq:	IRQ number to start with
+ * @nr_irqs:	The number of irqs to free
+ */
+void irq_domain_free_irqs_top(struct irq_domain *domain, unsigned int virq,
+			      unsigned int nr_irqs)
+{
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_set_handler_data(virq + i, NULL);
+		irq_set_handler(virq + i, NULL);
+	}
+	irq_domain_free_irqs_common(domain, virq, nr_irqs);
+}
+
+static void irq_domain_free_irqs_hierarchy(struct irq_domain *domain,
+					   unsigned int irq_base,
+					   unsigned int nr_irqs)
+{
+	unsigned int i;
+
+	if (!domain->ops->free)
+		return;
+
+	for (i = 0; i < nr_irqs; i++) {
+		if (irq_domain_get_irq_data(domain, irq_base + i))
+			domain->ops->free(domain, irq_base + i, 1);
+	}
+}
+
+int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain,
+				    unsigned int irq_base,
+				    unsigned int nr_irqs, void *arg)
+{
+	if (!domain->ops->alloc) {
+		pr_debug("domain->ops->alloc() is NULL\n");
+		return -ENOSYS;
+	}
+
+	return domain->ops->alloc(domain, irq_base, nr_irqs, arg);
+}
+
+/**
+ * __irq_domain_alloc_irqs - Allocate IRQs from domain
+ * @domain:	domain to allocate from
+ * @irq_base:	allocate specified IRQ nubmer if irq_base >= 0
+ * @nr_irqs:	number of IRQs to allocate
+ * @node:	NUMA node id for memory allocation
+ * @arg:	domain specific argument
+ * @realloc:	IRQ descriptors have already been allocated if true
+ * @affinity:	Optional irq affinity mask for multiqueue devices
+ *
+ * Allocate IRQ numbers and initialized all data structures to support
+ * hierarchy IRQ domains.
+ * Parameter @realloc is mainly to support legacy IRQs.
+ * Returns error code or allocated IRQ number
+ *
+ * The whole process to setup an IRQ has been split into two steps.
+ * The first step, __irq_domain_alloc_irqs(), is to allocate IRQ
+ * descriptor and required hardware resources. The second step,
+ * irq_domain_activate_irq(), is to program hardwares with preallocated
+ * resources. In this way, it's easier to rollback when failing to
+ * allocate resources.
+ */
+int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
+			    unsigned int nr_irqs, int node, void *arg,
+			    bool realloc, const struct cpumask *affinity)
+{
+	int i, ret, virq;
+
+	if (domain == NULL) {
+		domain = irq_default_domain;
+		if (WARN(!domain, "domain is NULL; cannot allocate IRQ\n"))
+			return -EINVAL;
+	}
+
+	if (realloc && irq_base >= 0) {
+		virq = irq_base;
+	} else {
+		virq = irq_domain_alloc_descs(irq_base, nr_irqs, 0, node,
+					      affinity);
+		if (virq < 0) {
+			pr_debug("cannot allocate IRQ(base %d, count %d)\n",
+				 irq_base, nr_irqs);
+			return virq;
+		}
+	}
+
+	if (irq_domain_alloc_irq_data(domain, virq, nr_irqs)) {
+		pr_debug("cannot allocate memory for IRQ%d\n", virq);
+		ret = -ENOMEM;
+		goto out_free_desc;
+	}
+
+	mutex_lock(&irq_domain_mutex);
+	ret = irq_domain_alloc_irqs_hierarchy(domain, virq, nr_irqs, arg);
+	if (ret < 0) {
+		mutex_unlock(&irq_domain_mutex);
+		goto out_free_irq_data;
+	}
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_insert_irq(virq + i);
+	mutex_unlock(&irq_domain_mutex);
+
+	return virq;
+
+out_free_irq_data:
+	irq_domain_free_irq_data(virq, nr_irqs);
+out_free_desc:
+	irq_free_descs(virq, nr_irqs);
+	return ret;
+}
+
+/* The irq_data was moved, fix the revmap to refer to the new location */
+static void irq_domain_fix_revmap(struct irq_data *d)
+{
+	void __rcu **slot;
+
+	if (d->hwirq < d->domain->revmap_size)
+		return; /* Not using radix tree. */
+
+	/* Fix up the revmap. */
+	mutex_lock(&d->domain->revmap_tree_mutex);
+	slot = radix_tree_lookup_slot(&d->domain->revmap_tree, d->hwirq);
+	if (slot)
+		radix_tree_replace_slot(&d->domain->revmap_tree, slot, d);
+	mutex_unlock(&d->domain->revmap_tree_mutex);
+}
+
+/**
+ * irq_domain_push_irq() - Push a domain in to the top of a hierarchy.
+ * @domain:	Domain to push.
+ * @virq:	Irq to push the domain in to.
+ * @arg:	Passed to the irq_domain_ops alloc() function.
+ *
+ * For an already existing irqdomain hierarchy, as might be obtained
+ * via a call to pci_enable_msix(), add an additional domain to the
+ * head of the processing chain.  Must be called before request_irq()
+ * has been called.
+ */
+int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg)
+{
+	struct irq_data *child_irq_data;
+	struct irq_data *root_irq_data = irq_get_irq_data(virq);
+	struct irq_desc *desc;
+	int rv = 0;
+
+	/*
+	 * Check that no action has been set, which indicates the virq
+	 * is in a state where this function doesn't have to deal with
+	 * races between interrupt handling and maintaining the
+	 * hierarchy.  This will catch gross misuse.  Attempting to
+	 * make the check race free would require holding locks across
+	 * calls to struct irq_domain_ops->alloc(), which could lead
+	 * to deadlock, so we just do a simple check before starting.
+	 */
+	desc = irq_to_desc(virq);
+	if (!desc)
+		return -EINVAL;
+	if (WARN_ON(desc->action))
+		return -EBUSY;
+
+	if (domain == NULL)
+		return -EINVAL;
+
+	if (WARN_ON(!irq_domain_is_hierarchy(domain)))
+		return -EINVAL;
+
+	if (!root_irq_data)
+		return -EINVAL;
+
+	if (domain->parent != root_irq_data->domain)
+		return -EINVAL;
+
+	child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL,
+				      irq_data_get_node(root_irq_data));
+	if (!child_irq_data)
+		return -ENOMEM;
+
+	mutex_lock(&irq_domain_mutex);
+
+	/* Copy the original irq_data. */
+	*child_irq_data = *root_irq_data;
+
+	/*
+	 * Overwrite the root_irq_data, which is embedded in struct
+	 * irq_desc, with values for this domain.
+	 */
+	root_irq_data->parent_data = child_irq_data;
+	root_irq_data->domain = domain;
+	root_irq_data->mask = 0;
+	root_irq_data->hwirq = 0;
+	root_irq_data->chip = NULL;
+	root_irq_data->chip_data = NULL;
+
+	/* May (probably does) set hwirq, chip, etc. */
+	rv = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
+	if (rv) {
+		/* Restore the original irq_data. */
+		*root_irq_data = *child_irq_data;
+		kfree(child_irq_data);
+		goto error;
+	}
+
+	irq_domain_fix_revmap(child_irq_data);
+	irq_domain_set_mapping(domain, root_irq_data->hwirq, root_irq_data);
+
+error:
+	mutex_unlock(&irq_domain_mutex);
+
+	return rv;
+}
+EXPORT_SYMBOL_GPL(irq_domain_push_irq);
+
+/**
+ * irq_domain_pop_irq() - Remove a domain from the top of a hierarchy.
+ * @domain:	Domain to remove.
+ * @virq:	Irq to remove the domain from.
+ *
+ * Undo the effects of a call to irq_domain_push_irq().  Must be
+ * called either before request_irq() or after free_irq().
+ */
+int irq_domain_pop_irq(struct irq_domain *domain, int virq)
+{
+	struct irq_data *root_irq_data = irq_get_irq_data(virq);
+	struct irq_data *child_irq_data;
+	struct irq_data *tmp_irq_data;
+	struct irq_desc *desc;
+
+	/*
+	 * Check that no action is set, which indicates the virq is in
+	 * a state where this function doesn't have to deal with races
+	 * between interrupt handling and maintaining the hierarchy.
+	 * This will catch gross misuse.  Attempting to make the check
+	 * race free would require holding locks across calls to
+	 * struct irq_domain_ops->free(), which could lead to
+	 * deadlock, so we just do a simple check before starting.
+	 */
+	desc = irq_to_desc(virq);
+	if (!desc)
+		return -EINVAL;
+	if (WARN_ON(desc->action))
+		return -EBUSY;
+
+	if (domain == NULL)
+		return -EINVAL;
+
+	if (!root_irq_data)
+		return -EINVAL;
+
+	tmp_irq_data = irq_domain_get_irq_data(domain, virq);
+
+	/* We can only "pop" if this domain is at the top of the list */
+	if (WARN_ON(root_irq_data != tmp_irq_data))
+		return -EINVAL;
+
+	if (WARN_ON(root_irq_data->domain != domain))
+		return -EINVAL;
+
+	child_irq_data = root_irq_data->parent_data;
+	if (WARN_ON(!child_irq_data))
+		return -EINVAL;
+
+	mutex_lock(&irq_domain_mutex);
+
+	root_irq_data->parent_data = NULL;
+
+	irq_domain_clear_mapping(domain, root_irq_data->hwirq);
+	irq_domain_free_irqs_hierarchy(domain, virq, 1);
+
+	/* Restore the original irq_data. */
+	*root_irq_data = *child_irq_data;
+
+	irq_domain_fix_revmap(root_irq_data);
+
+	mutex_unlock(&irq_domain_mutex);
+
+	kfree(child_irq_data);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_pop_irq);
+
+/**
+ * irq_domain_free_irqs - Free IRQ number and associated data structures
+ * @virq:	base IRQ number
+ * @nr_irqs:	number of IRQs to free
+ */
+void irq_domain_free_irqs(unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *data = irq_get_irq_data(virq);
+	int i;
+
+	if (WARN(!data || !data->domain || !data->domain->ops->free,
+		 "NULL pointer, cannot free irq\n"))
+		return;
+
+	mutex_lock(&irq_domain_mutex);
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_remove_irq(virq + i);
+	irq_domain_free_irqs_hierarchy(data->domain, virq, nr_irqs);
+	mutex_unlock(&irq_domain_mutex);
+
+	irq_domain_free_irq_data(virq, nr_irqs);
+	irq_free_descs(virq, nr_irqs);
+}
+
+/**
+ * irq_domain_alloc_irqs_parent - Allocate interrupts from parent domain
+ * @irq_base:	Base IRQ number
+ * @nr_irqs:	Number of IRQs to allocate
+ * @arg:	Allocation data (arch/domain specific)
+ *
+ * Check whether the domain has been setup recursive. If not allocate
+ * through the parent domain.
+ */
+int irq_domain_alloc_irqs_parent(struct irq_domain *domain,
+				 unsigned int irq_base, unsigned int nr_irqs,
+				 void *arg)
+{
+	if (!domain->parent)
+		return -ENOSYS;
+
+	return irq_domain_alloc_irqs_hierarchy(domain->parent, irq_base,
+					       nr_irqs, arg);
+}
+EXPORT_SYMBOL_GPL(irq_domain_alloc_irqs_parent);
+
+/**
+ * irq_domain_free_irqs_parent - Free interrupts from parent domain
+ * @irq_base:	Base IRQ number
+ * @nr_irqs:	Number of IRQs to free
+ *
+ * Check whether the domain has been setup recursive. If not free
+ * through the parent domain.
+ */
+void irq_domain_free_irqs_parent(struct irq_domain *domain,
+				 unsigned int irq_base, unsigned int nr_irqs)
+{
+	if (!domain->parent)
+		return;
+
+	irq_domain_free_irqs_hierarchy(domain->parent, irq_base, nr_irqs);
+}
+EXPORT_SYMBOL_GPL(irq_domain_free_irqs_parent);
+
+static void __irq_domain_deactivate_irq(struct irq_data *irq_data)
+{
+	if (irq_data && irq_data->domain) {
+		struct irq_domain *domain = irq_data->domain;
+
+		if (domain->ops->deactivate)
+			domain->ops->deactivate(domain, irq_data);
+		if (irq_data->parent_data)
+			__irq_domain_deactivate_irq(irq_data->parent_data);
+	}
+}
+
+static int __irq_domain_activate_irq(struct irq_data *irqd, bool reserve)
+{
+	int ret = 0;
+
+	if (irqd && irqd->domain) {
+		struct irq_domain *domain = irqd->domain;
+
+		if (irqd->parent_data)
+			ret = __irq_domain_activate_irq(irqd->parent_data,
+							reserve);
+		if (!ret && domain->ops->activate) {
+			ret = domain->ops->activate(domain, irqd, reserve);
+			/* Rollback in case of error */
+			if (ret && irqd->parent_data)
+				__irq_domain_deactivate_irq(irqd->parent_data);
+		}
+	}
+	return ret;
+}
+
+/**
+ * irq_domain_activate_irq - Call domain_ops->activate recursively to activate
+ *			     interrupt
+ * @irq_data:	Outermost irq_data associated with interrupt
+ * @reserve:	If set only reserve an interrupt vector instead of assigning one
+ *
+ * This is the second step to call domain_ops->activate to program interrupt
+ * controllers, so the interrupt could actually get delivered.
+ */
+int irq_domain_activate_irq(struct irq_data *irq_data, bool reserve)
+{
+	int ret = 0;
+
+	if (!irqd_is_activated(irq_data))
+		ret = __irq_domain_activate_irq(irq_data, reserve);
+	if (!ret)
+		irqd_set_activated(irq_data);
+	return ret;
+}
+
+/**
+ * irq_domain_deactivate_irq - Call domain_ops->deactivate recursively to
+ *			       deactivate interrupt
+ * @irq_data: outermost irq_data associated with interrupt
+ *
+ * It calls domain_ops->deactivate to program interrupt controllers to disable
+ * interrupt delivery.
+ */
+void irq_domain_deactivate_irq(struct irq_data *irq_data)
+{
+	if (irqd_is_activated(irq_data)) {
+		__irq_domain_deactivate_irq(irq_data);
+		irqd_clr_activated(irq_data);
+	}
+}
+
+static void irq_domain_check_hierarchy(struct irq_domain *domain)
+{
+	/* Hierarchy irq_domains must implement callback alloc() */
+	if (domain->ops->alloc)
+		domain->flags |= IRQ_DOMAIN_FLAG_HIERARCHY;
+}
+
+/**
+ * irq_domain_hierarchical_is_msi_remap - Check if the domain or any
+ * parent has MSI remapping support
+ * @domain: domain pointer
+ */
+bool irq_domain_hierarchical_is_msi_remap(struct irq_domain *domain)
+{
+	for (; domain; domain = domain->parent) {
+		if (irq_domain_is_msi_remap(domain))
+			return true;
+	}
+	return false;
+}
+#else	/* CONFIG_IRQ_DOMAIN_HIERARCHY */
+/**
+ * irq_domain_get_irq_data - Get irq_data associated with @virq and @domain
+ * @domain:	domain to match
+ * @virq:	IRQ number to get irq_data
+ */
+struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain,
+					 unsigned int virq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+
+	return (irq_data && irq_data->domain == domain) ? irq_data : NULL;
+}
+EXPORT_SYMBOL_GPL(irq_domain_get_irq_data);
+
+/**
+ * irq_domain_set_info - Set the complete data for a @virq in @domain
+ * @domain:		Interrupt domain to match
+ * @virq:		IRQ number
+ * @hwirq:		The hardware interrupt number
+ * @chip:		The associated interrupt chip
+ * @chip_data:		The associated interrupt chip data
+ * @handler:		The interrupt flow handler
+ * @handler_data:	The interrupt flow handler data
+ * @handler_name:	The interrupt handler name
+ */
+void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
+			 irq_hw_number_t hwirq, struct irq_chip *chip,
+			 void *chip_data, irq_flow_handler_t handler,
+			 void *handler_data, const char *handler_name)
+{
+	irq_set_chip_and_handler_name(virq, chip, handler, handler_name);
+	irq_set_chip_data(virq, chip_data);
+	irq_set_handler_data(virq, handler_data);
+}
+
+static void irq_domain_check_hierarchy(struct irq_domain *domain)
+{
+}
+#endif	/* CONFIG_IRQ_DOMAIN_HIERARCHY */
+
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+static struct dentry *domain_dir;
+
+static void
+irq_domain_debug_show_one(struct seq_file *m, struct irq_domain *d, int ind)
+{
+	seq_printf(m, "%*sname:   %s\n", ind, "", d->name);
+	seq_printf(m, "%*ssize:   %u\n", ind + 1, "",
+		   d->revmap_size + d->revmap_direct_max_irq);
+	seq_printf(m, "%*smapped: %u\n", ind + 1, "", d->mapcount);
+	seq_printf(m, "%*sflags:  0x%08x\n", ind +1 , "", d->flags);
+	if (d->ops && d->ops->debug_show)
+		d->ops->debug_show(m, d, NULL, ind + 1);
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+	if (!d->parent)
+		return;
+	seq_printf(m, "%*sparent: %s\n", ind + 1, "", d->parent->name);
+	irq_domain_debug_show_one(m, d->parent, ind + 4);
+#endif
+}
+
+static int irq_domain_debug_show(struct seq_file *m, void *p)
+{
+	struct irq_domain *d = m->private;
+
+	/* Default domain? Might be NULL */
+	if (!d) {
+		if (!irq_default_domain)
+			return 0;
+		d = irq_default_domain;
+	}
+	irq_domain_debug_show_one(m, d, 0);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(irq_domain_debug);
+
+static void debugfs_add_domain_dir(struct irq_domain *d)
+{
+	if (!d->name || !domain_dir || d->debugfs_file)
+		return;
+	d->debugfs_file = debugfs_create_file(d->name, 0444, domain_dir, d,
+					      &irq_domain_debug_fops);
+}
+
+static void debugfs_remove_domain_dir(struct irq_domain *d)
+{
+	debugfs_remove(d->debugfs_file);
+}
+
+void __init irq_domain_debugfs_init(struct dentry *root)
+{
+	struct irq_domain *d;
+
+	domain_dir = debugfs_create_dir("domains", root);
+	if (!domain_dir)
+		return;
+
+	debugfs_create_file("default", 0444, domain_dir, NULL,
+			    &irq_domain_debug_fops);
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(d, &irq_domain_list, link)
+		debugfs_add_domain_dir(d);
+	mutex_unlock(&irq_domain_mutex);
+}
+#endif