1 files changed, 966 insertions, 0 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
new file mode 100644
index 000000000..3633540b0
--- /dev/null
+++ b/kernel/irq/irqdesc.c
@@ -0,0 +1,966 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
+ *
+ * This file contains the interrupt descriptor management code. Detailed
+ * information is available in Documentation/core-api/genericirq.rst
+ *
+ */
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/radix-tree.h>
+#include <linux/bitmap.h>
+#include <linux/irqdomain.h>
+#include <linux/sysfs.h>
+
+#include "internals.h"
+
+/*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+static struct lock_class_key irq_desc_lock_class;
+
+#if defined(CONFIG_SMP)
+static int __init irq_affinity_setup(char *str)
+{
+	alloc_bootmem_cpumask_var(&irq_default_affinity);
+	cpulist_parse(str, irq_default_affinity);
+	/*
+	 * Set at least the boot cpu. We don't want to end up with
+	 * bugreports caused by random comandline masks
+	 */
+	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
+	return 1;
+}
+__setup("irqaffinity=", irq_affinity_setup);
+
+static void __init init_irq_default_affinity(void)
+{
+	if (!cpumask_available(irq_default_affinity))
+		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
+	if (cpumask_empty(irq_default_affinity))
+		cpumask_setall(irq_default_affinity);
+}
+#else
+static void __init init_irq_default_affinity(void)
+{
+}
+#endif
+
+#ifdef CONFIG_SMP
+static int alloc_masks(struct irq_desc *desc, int node)
+{
+	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
+				     GFP_KERNEL, node))
+		return -ENOMEM;
+
+#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
+	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
+				     GFP_KERNEL, node)) {
+		free_cpumask_var(desc->irq_common_data.affinity);
+		return -ENOMEM;
+	}
+#endif
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
+#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
+		free_cpumask_var(desc->irq_common_data.effective_affinity);
+#endif
+		free_cpumask_var(desc->irq_common_data.affinity);
+		return -ENOMEM;
+	}
+#endif
+	return 0;
+}
+
+static void desc_smp_init(struct irq_desc *desc, int node,
+			  const struct cpumask *affinity)
+{
+	if (!affinity)
+		affinity = irq_default_affinity;
+	cpumask_copy(desc->irq_common_data.affinity, affinity);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	cpumask_clear(desc->pending_mask);
+#endif
+#ifdef CONFIG_NUMA
+	desc->irq_common_data.node = node;
+#endif
+}
+
+#else
+static inline int
+alloc_masks(struct irq_desc *desc, int node) { return 0; }
+static inline void
+desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
+#endif
+
+static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
+			      const struct cpumask *affinity, struct module *owner)
+{
+	int cpu;
+
+	desc->irq_common_data.handler_data = NULL;
+	desc->irq_common_data.msi_desc = NULL;
+
+	desc->irq_data.common = &desc->irq_common_data;
+	desc->irq_data.irq = irq;
+	desc->irq_data.chip = &no_irq_chip;
+	desc->irq_data.chip_data = NULL;
+	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
+	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
+	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
+	desc->handle_irq = handle_bad_irq;
+	desc->depth = 1;
+	desc->irq_count = 0;
+	desc->irqs_unhandled = 0;
+	desc->tot_count = 0;
+	desc->name = NULL;
+	desc->owner = owner;
+	for_each_possible_cpu(cpu)
+		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
+	desc_smp_init(desc, node, affinity);
+}
+
+int nr_irqs = NR_IRQS;
+EXPORT_SYMBOL_GPL(nr_irqs);
+
+static DEFINE_MUTEX(sparse_irq_lock);
+static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
+
+#ifdef CONFIG_SPARSE_IRQ
+
+static void irq_kobj_release(struct kobject *kobj);
+
+#ifdef CONFIG_SYSFS
+static struct kobject *irq_kobj_base;
+
+#define IRQ_ATTR_RO(_name) \
+static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+static ssize_t per_cpu_count_show(struct kobject *kobj,
+				  struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	int cpu, irq = desc->irq_data.irq;
+	ssize_t ret = 0;
+	char *p = "";
+
+	for_each_possible_cpu(cpu) {
+		unsigned int c = kstat_irqs_cpu(irq, cpu);
+
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
+		p = ",";
+	}
+
+	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
+	return ret;
+}
+IRQ_ATTR_RO(per_cpu_count);
+
+static ssize_t chip_name_show(struct kobject *kobj,
+			      struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	if (desc->irq_data.chip && desc->irq_data.chip->name) {
+		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
+				desc->irq_data.chip->name);
+	}
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+}
+IRQ_ATTR_RO(chip_name);
+
+static ssize_t hwirq_show(struct kobject *kobj,
+			  struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	if (desc->irq_data.domain)
+		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+}
+IRQ_ATTR_RO(hwirq);
+
+static ssize_t type_show(struct kobject *kobj,
+			 struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	ret = sprintf(buf, "%s\n",
+		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+
+}
+IRQ_ATTR_RO(type);
+
+static ssize_t wakeup_show(struct kobject *kobj,
+			   struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	ret = sprintf(buf, "%s\n",
+		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+
+}
+IRQ_ATTR_RO(wakeup);
+
+static ssize_t name_show(struct kobject *kobj,
+			 struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	if (desc->name)
+		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+}
+IRQ_ATTR_RO(name);
+
+static ssize_t actions_show(struct kobject *kobj,
+			    struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	struct irqaction *action;
+	ssize_t ret = 0;
+	char *p = "";
+
+	raw_spin_lock_irq(&desc->lock);
+	for (action = desc->action; action != NULL; action = action->next) {
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
+				 p, action->name);
+		p = ",";
+	}
+	raw_spin_unlock_irq(&desc->lock);
+
+	if (ret)
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
+
+	return ret;
+}
+IRQ_ATTR_RO(actions);
+
+static struct attribute *irq_attrs[] = {
+	&per_cpu_count_attr.attr,
+	&chip_name_attr.attr,
+	&hwirq_attr.attr,
+	&type_attr.attr,
+	&wakeup_attr.attr,
+	&name_attr.attr,
+	&actions_attr.attr,
+	NULL
+};
+
+static struct kobj_type irq_kobj_type = {
+	.release	= irq_kobj_release,
+	.sysfs_ops	= &kobj_sysfs_ops,
+	.default_attrs	= irq_attrs,
+};
+
+static void irq_sysfs_add(int irq, struct irq_desc *desc)
+{
+	if (irq_kobj_base) {
+		/*
+		 * Continue even in case of failure as this is nothing
+		 * crucial.
+		 */
+		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
+			pr_warn("Failed to add kobject for irq %d\n", irq);
+	}
+}
+
+static void irq_sysfs_del(struct irq_desc *desc)
+{
+	/*
+	 * If irq_sysfs_init() has not yet been invoked (early boot), then
+	 * irq_kobj_base is NULL and the descriptor was never added.
+	 * kobject_del() complains about a object with no parent, so make
+	 * it conditional.
+	 */
+	if (irq_kobj_base)
+		kobject_del(&desc->kobj);
+}
+
+static int __init irq_sysfs_init(void)
+{
+	struct irq_desc *desc;
+	int irq;
+
+	/* Prevent concurrent irq alloc/free */
+	irq_lock_sparse();
+
+	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
+	if (!irq_kobj_base) {
+		irq_unlock_sparse();
+		return -ENOMEM;
+	}
+
+	/* Add the already allocated interrupts */
+	for_each_irq_desc(irq, desc)
+		irq_sysfs_add(irq, desc);
+	irq_unlock_sparse();
+
+	return 0;
+}
+postcore_initcall(irq_sysfs_init);
+
+#else /* !CONFIG_SYSFS */
+
+static struct kobj_type irq_kobj_type = {
+	.release	= irq_kobj_release,
+};
+
+static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
+static void irq_sysfs_del(struct irq_desc *desc) {}
+
+#endif /* CONFIG_SYSFS */
+
+static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
+
+static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
+{
+	radix_tree_insert(&irq_desc_tree, irq, desc);
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+	return radix_tree_lookup(&irq_desc_tree, irq);
+}
+EXPORT_SYMBOL(irq_to_desc);
+
+static void delete_irq_desc(unsigned int irq)
+{
+	radix_tree_delete(&irq_desc_tree, irq);
+}
+
+#ifdef CONFIG_SMP
+static void free_masks(struct irq_desc *desc)
+{
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+	free_cpumask_var(desc->pending_mask);
+#endif
+	free_cpumask_var(desc->irq_common_data.affinity);
+#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
+	free_cpumask_var(desc->irq_common_data.effective_affinity);
+#endif
+}
+#else
+static inline void free_masks(struct irq_desc *desc) { }
+#endif
+
+void irq_lock_sparse(void)
+{
+	mutex_lock(&sparse_irq_lock);
+}
+
+void irq_unlock_sparse(void)
+{
+	mutex_unlock(&sparse_irq_lock);
+}
+
+static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
+				   const struct cpumask *affinity,
+				   struct module *owner)
+{
+	struct irq_desc *desc;
+
+	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
+	if (!desc)
+		return NULL;
+	/* allocate based on nr_cpu_ids */
+	desc->kstat_irqs = alloc_percpu(unsigned int);
+	if (!desc->kstat_irqs)
+		goto err_desc;
+
+	if (alloc_masks(desc, node))
+		goto err_kstat;
+
+	raw_spin_lock_init(&desc->lock);
+	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+	mutex_init(&desc->request_mutex);
+	init_rcu_head(&desc->rcu);
+	init_waitqueue_head(&desc->wait_for_threads);
+
+	desc_set_defaults(irq, desc, node, affinity, owner);
+	irqd_set(&desc->irq_data, flags);
+	kobject_init(&desc->kobj, &irq_kobj_type);
+
+	return desc;
+
+err_kstat:
+	free_percpu(desc->kstat_irqs);
+err_desc:
+	kfree(desc);
+	return NULL;
+}
+
+static void irq_kobj_release(struct kobject *kobj)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+
+	free_masks(desc);
+	free_percpu(desc->kstat_irqs);
+	kfree(desc);
+}
+
+static void delayed_free_desc(struct rcu_head *rhp)
+{
+	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
+
+	kobject_put(&desc->kobj);
+}
+
+static void free_desc(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	irq_remove_debugfs_entry(desc);
+	unregister_irq_proc(irq, desc);
+
+	/*
+	 * sparse_irq_lock protects also show_interrupts() and
+	 * kstat_irq_usr(). Once we deleted the descriptor from the
+	 * sparse tree we can free it. Access in proc will fail to
+	 * lookup the descriptor.
+	 *
+	 * The sysfs entry must be serialized against a concurrent
+	 * irq_sysfs_init() as well.
+	 */
+	irq_sysfs_del(desc);
+	delete_irq_desc(irq);
+
+	/*
+	 * We free the descriptor, masks and stat fields via RCU. That
+	 * allows demultiplex interrupts to do rcu based management of
+	 * the child interrupts.
+	 * This also allows us to use rcu in kstat_irqs_usr().
+	 */
+	call_rcu(&desc->rcu, delayed_free_desc);
+}
+
+static int alloc_descs(unsigned int start, unsigned int cnt, int node,
+		       const struct cpumask *affinity, struct module *owner)
+{
+	const struct cpumask *mask = NULL;
+	struct irq_desc *desc;
+	unsigned int flags;
+	int i;
+
+	/* Validate affinity mask(s) */
+	if (affinity) {
+		for (i = 0, mask = affinity; i < cnt; i++, mask++) {
+			if (cpumask_empty(mask))
+				return -EINVAL;
+		}
+	}
+
+	flags = affinity ? IRQD_AFFINITY_MANAGED | IRQD_MANAGED_SHUTDOWN : 0;
+	mask = NULL;
+
+	for (i = 0; i < cnt; i++) {
+		if (affinity) {
+			node = cpu_to_node(cpumask_first(affinity));
+			mask = affinity;
+			affinity++;
+		}
+		desc = alloc_desc(start + i, node, flags, mask, owner);
+		if (!desc)
+			goto err;
+		irq_insert_desc(start + i, desc);
+		irq_sysfs_add(start + i, desc);
+		irq_add_debugfs_entry(start + i, desc);
+	}
+	bitmap_set(allocated_irqs, start, cnt);
+	return start;
+
+err:
+	for (i--; i >= 0; i--)
+		free_desc(start + i);
+	return -ENOMEM;
+}
+
+static int irq_expand_nr_irqs(unsigned int nr)
+{
+	if (nr > IRQ_BITMAP_BITS)
+		return -ENOMEM;
+	nr_irqs = nr;
+	return 0;
+}
+
+int __init early_irq_init(void)
+{
+	int i, initcnt, node = first_online_node;
+	struct irq_desc *desc;
+
+	init_irq_default_affinity();
+
+	/* Let arch update nr_irqs and return the nr of preallocated irqs */
+	initcnt = arch_probe_nr_irqs();
+	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
+	       NR_IRQS, nr_irqs, initcnt);
+
+	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
+		nr_irqs = IRQ_BITMAP_BITS;
+
+	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
+		initcnt = IRQ_BITMAP_BITS;
+
+	if (initcnt > nr_irqs)
+		nr_irqs = initcnt;
+
+	for (i = 0; i < initcnt; i++) {
+		desc = alloc_desc(i, node, 0, NULL, NULL);
+		set_bit(i, allocated_irqs);
+		irq_insert_desc(i, desc);
+	}
+	return arch_early_irq_init();
+}
+
+#else /* !CONFIG_SPARSE_IRQ */
+
+struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
+	[0 ... NR_IRQS-1] = {
+		.handle_irq	= handle_bad_irq,
+		.depth		= 1,
+		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
+	}
+};
+
+int __init early_irq_init(void)
+{
+	int count, i, node = first_online_node;
+	struct irq_desc *desc;
+
+	init_irq_default_affinity();
+
+	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
+
+	desc = irq_desc;
+	count = ARRAY_SIZE(irq_desc);
+
+	for (i = 0; i < count; i++) {
+		desc[i].kstat_irqs = alloc_percpu(unsigned int);
+		alloc_masks(&desc[i], node);
+		raw_spin_lock_init(&desc[i].lock);
+		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
+		mutex_init(&desc[i].request_mutex);
+		init_waitqueue_head(&desc[i].wait_for_threads);
+		desc_set_defaults(i, &desc[i], node, NULL, NULL);
+	}
+	return arch_early_irq_init();
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
+}
+EXPORT_SYMBOL(irq_to_desc);
+
+static void free_desc(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&desc->lock, flags);
+	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
+	raw_spin_unlock_irqrestore(&desc->lock, flags);
+}
+
+static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
+			      const struct cpumask *affinity,
+			      struct module *owner)
+{
+	u32 i;
+
+	for (i = 0; i < cnt; i++) {
+		struct irq_desc *desc = irq_to_desc(start + i);
+
+		desc->owner = owner;
+	}
+	bitmap_set(allocated_irqs, start, cnt);
+	return start;
+}
+
+static int irq_expand_nr_irqs(unsigned int nr)
+{
+	return -ENOMEM;
+}
+
+void irq_mark_irq(unsigned int irq)
+{
+	mutex_lock(&sparse_irq_lock);
+	bitmap_set(allocated_irqs, irq, 1);
+	mutex_unlock(&sparse_irq_lock);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_LEGACY
+void irq_init_desc(unsigned int irq)
+{
+	free_desc(irq);
+}
+#endif
+
+#endif /* !CONFIG_SPARSE_IRQ */
+
+/**
+ * generic_handle_irq - Invoke the handler for a particular irq
+ * @irq:	The irq number to handle
+ *
+ */
+int generic_handle_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (!desc)
+		return -EINVAL;
+	generic_handle_irq_desc(desc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(generic_handle_irq);
+
+#ifdef CONFIG_HANDLE_DOMAIN_IRQ
+/**
+ * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
+ * @domain:	The domain where to perform the lookup
+ * @hwirq:	The HW irq number to convert to a logical one
+ * @lookup:	Whether to perform the domain lookup or not
+ * @regs:	Register file coming from the low-level handling code
+ *
+ * Returns:	0 on success, or -EINVAL if conversion has failed
+ */
+int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
+			bool lookup, struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	unsigned int irq = hwirq;
+	int ret = 0;
+
+	irq_enter();
+
+#ifdef CONFIG_IRQ_DOMAIN
+	if (lookup)
+		irq = irq_find_mapping(domain, hwirq);
+#endif
+
+	/*
+	 * Some hardware gives randomly wrong interrupts.  Rather
+	 * than crashing, do something sensible.
+	 */
+	if (unlikely(!irq || irq >= nr_irqs)) {
+		ack_bad_irq(irq);
+		ret = -EINVAL;
+	} else {
+		generic_handle_irq(irq);
+	}
+
+	irq_exit();
+	set_irq_regs(old_regs);
+	return ret;
+}
+#endif
+
+/* Dynamic interrupt handling */
+
+/**
+ * irq_free_descs - free irq descriptors
+ * @from:	Start of descriptor range
+ * @cnt:	Number of consecutive irqs to free
+ */
+void irq_free_descs(unsigned int from, unsigned int cnt)
+{
+	int i;
+
+	if (from >= nr_irqs || (from + cnt) > nr_irqs)
+		return;
+
+	mutex_lock(&sparse_irq_lock);
+	for (i = 0; i < cnt; i++)
+		free_desc(from + i);
+
+	bitmap_clear(allocated_irqs, from, cnt);
+	mutex_unlock(&sparse_irq_lock);
+}
+EXPORT_SYMBOL_GPL(irq_free_descs);
+
+/**
+ * irq_alloc_descs - allocate and initialize a range of irq descriptors
+ * @irq:	Allocate for specific irq number if irq >= 0
+ * @from:	Start the search from this irq number
+ * @cnt:	Number of consecutive irqs to allocate.
+ * @node:	Preferred node on which the irq descriptor should be allocated
+ * @owner:	Owning module (can be NULL)
+ * @affinity:	Optional pointer to an affinity mask array of size @cnt which
+ *		hints where the irq descriptors should be allocated and which
+ *		default affinities to use
+ *
+ * Returns the first irq number or error code
+ */
+int __ref
+__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
+		  struct module *owner, const struct cpumask *affinity)
+{
+	int start, ret;
+
+	if (!cnt)
+		return -EINVAL;
+
+	if (irq >= 0) {
+		if (from > irq)
+			return -EINVAL;
+		from = irq;
+	} else {
+		/*
+		 * For interrupts which are freely allocated the
+		 * architecture can force a lower bound to the @from
+		 * argument. x86 uses this to exclude the GSI space.
+		 */
+		from = arch_dynirq_lower_bound(from);
+	}
+
+	mutex_lock(&sparse_irq_lock);
+
+	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
+					   from, cnt, 0);
+	ret = -EEXIST;
+	if (irq >=0 && start != irq)
+		goto unlock;
+
+	if (start + cnt > nr_irqs) {
+		ret = irq_expand_nr_irqs(start + cnt);
+		if (ret)
+			goto unlock;
+	}
+	ret = alloc_descs(start, cnt, node, affinity, owner);
+unlock:
+	mutex_unlock(&sparse_irq_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__irq_alloc_descs);
+
+#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
+/**
+ * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
+ * @cnt:	number of interrupts to allocate
+ * @node:	node on which to allocate
+ *
+ * Returns an interrupt number > 0 or 0, if the allocation fails.
+ */
+unsigned int irq_alloc_hwirqs(int cnt, int node)
+{
+	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
+
+	if (irq < 0)
+		return 0;
+
+	for (i = irq; cnt > 0; i++, cnt--) {
+		if (arch_setup_hwirq(i, node))
+			goto err;
+		irq_clear_status_flags(i, _IRQ_NOREQUEST);
+	}
+	return irq;
+
+err:
+	for (i--; i >= irq; i--) {
+		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
+		arch_teardown_hwirq(i);
+	}
+	irq_free_descs(irq, cnt);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
+
+/**
+ * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
+ * @from:	Free from irq number
+ * @cnt:	number of interrupts to free
+ *
+ */
+void irq_free_hwirqs(unsigned int from, int cnt)
+{
+	int i, j;
+
+	for (i = from, j = cnt; j > 0; i++, j--) {
+		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
+		arch_teardown_hwirq(i);
+	}
+	irq_free_descs(from, cnt);
+}
+EXPORT_SYMBOL_GPL(irq_free_hwirqs);
+#endif
+
+/**
+ * irq_get_next_irq - get next allocated irq number
+ * @offset:	where to start the search
+ *
+ * Returns next irq number after offset or nr_irqs if none is found.
+ */
+unsigned int irq_get_next_irq(unsigned int offset)
+{
+	return find_next_bit(allocated_irqs, nr_irqs, offset);
+}
+
+struct irq_desc *
+__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
+		    unsigned int check)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (desc) {
+		if (check & _IRQ_DESC_CHECK) {
+			if ((check & _IRQ_DESC_PERCPU) &&
+			    !irq_settings_is_per_cpu_devid(desc))
+				return NULL;
+
+			if (!(check & _IRQ_DESC_PERCPU) &&
+			    irq_settings_is_per_cpu_devid(desc))
+				return NULL;
+		}
+
+		if (bus)
+			chip_bus_lock(desc);
+		raw_spin_lock_irqsave(&desc->lock, *flags);
+	}
+	return desc;
+}
+
+void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
+{
+	raw_spin_unlock_irqrestore(&desc->lock, flags);
+	if (bus)
+		chip_bus_sync_unlock(desc);
+}
+
+int irq_set_percpu_devid_partition(unsigned int irq,
+				   const struct cpumask *affinity)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (!desc)
+		return -EINVAL;
+
+	if (desc->percpu_enabled)
+		return -EINVAL;
+
+	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
+
+	if (!desc->percpu_enabled)
+		return -ENOMEM;
+
+	if (affinity)
+		desc->percpu_affinity = affinity;
+	else
+		desc->percpu_affinity = cpu_possible_mask;
+
+	irq_set_percpu_devid_flags(irq);
+	return 0;
+}
+
+int irq_set_percpu_devid(unsigned int irq)
+{
+	return irq_set_percpu_devid_partition(irq, NULL);
+}
+
+int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (!desc || !desc->percpu_enabled)
+		return -EINVAL;
+
+	if (affinity)
+		cpumask_copy(affinity, desc->percpu_affinity);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
+
+void kstat_incr_irq_this_cpu(unsigned int irq)
+{
+	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
+}
+
+/**
+ * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
+ * @irq:	The interrupt number
+ * @cpu:	The cpu number
+ *
+ * Returns the sum of interrupt counts on @cpu since boot for
+ * @irq. The caller must ensure that the interrupt is not removed
+ * concurrently.
+ */
+unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	return desc && desc->kstat_irqs ?
+			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
+}
+
+/**
+ * kstat_irqs - Get the statistics for an interrupt
+ * @irq:	The interrupt number
+ *
+ * Returns the sum of interrupt counts on all cpus since boot for
+ * @irq. The caller must ensure that the interrupt is not removed
+ * concurrently.
+ */
+unsigned int kstat_irqs(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+	unsigned int sum = 0;
+	int cpu;
+
+	if (!desc || !desc->kstat_irqs)
+		return 0;
+	if (!irq_settings_is_per_cpu_devid(desc) &&
+	    !irq_settings_is_per_cpu(desc))
+	    return desc->tot_count;
+
+	for_each_possible_cpu(cpu)
+		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
+	return sum;
+}
+
+/**
+ * kstat_irqs_usr - Get the statistics for an interrupt
+ * @irq:	The interrupt number
+ *
+ * Returns the sum of interrupt counts on all cpus since boot for @irq.
+ * Contrary to kstat_irqs() this can be called from any context.
+ * It uses rcu since a concurrent removal of an interrupt descriptor is
+ * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
+ */
+unsigned int kstat_irqs_usr(unsigned int irq)
+{
+	unsigned int sum;
+
+	rcu_read_lock();
+	sum = kstat_irqs(irq);
+	rcu_read_unlock();
+	return sum;
+}