irq_domain: Move irq_domain code from powerpc to kernel/irq

This patch only moves the code.  It doesn't make any changes, and the
code is still only compiled for powerpc.  Follow-on patches will generalize
the code for other architectures.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>

1 files changed, 600 insertions, 0 deletions

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 509adb8762d7..f551bc1d3167 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1,14 +1,612 @@
+#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/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);
 
+#ifdef CONFIG_PPC
+static DEFINE_MUTEX(revmap_trees_mutex);
+static unsigned int irq_virq_count = NR_IRQS;
+static struct irq_domain *irq_default_host;
+
+static int default_irq_host_match(struct irq_domain *h, struct device_node *np)
+{
+	return h->of_node != NULL && h->of_node == np;
+}
+
+/**
+ * irq_alloc_host() - Allocate a new irq_domain data structure
+ * @of_node: optional device-tree node of the interrupt controller
+ * @revmap_type: type of reverse mapping to use
+ * @revmap_arg: for IRQ_DOMAIN_MAP_LINEAR linear only: size of the map
+ * @ops: map/unmap host callbacks
+ * @inval_irq: provide a hw number in that host space that is always invalid
+ *
+ * Allocates and initialize and irq_domain structure. Note that in the case of
+ * IRQ_DOMAIN_MAP_LEGACY, the map() callback will be called before this returns
+ * for all legacy interrupts except 0 (which is always the invalid irq for
+ * a legacy controller). For a IRQ_DOMAIN_MAP_LINEAR, the map is allocated by
+ * this call as well. For a IRQ_DOMAIN_MAP_TREE, the radix tree will be
+ * allocated later during boot automatically (the reverse mapping will use the
+ * slow path until that happens).
+ */
+struct irq_domain *irq_alloc_host(struct device_node *of_node,
+				unsigned int revmap_type,
+				unsigned int revmap_arg,
+				struct irq_domain_ops *ops,
+				irq_hw_number_t inval_irq)
+{
+	struct irq_domain *host, *h;
+	unsigned int size = sizeof(struct irq_domain);
+	unsigned int i;
+	unsigned int *rmap;
+
+	/* Allocate structure and revmap table if using linear mapping */
+	if (revmap_type == IRQ_DOMAIN_MAP_LINEAR)
+		size += revmap_arg * sizeof(unsigned int);
+	host = kzalloc(size, GFP_KERNEL);
+	if (host == NULL)
+		return NULL;
+
+	/* Fill structure */
+	host->revmap_type = revmap_type;
+	host->inval_irq = inval_irq;
+	host->ops = ops;
+	host->of_node = of_node_get(of_node);
+
+	if (host->ops->match == NULL)
+		host->ops->match = default_irq_host_match;
+
+	mutex_lock(&irq_domain_mutex);
+	/* Make sure only one legacy controller can be created */
+	if (revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
+		list_for_each_entry(h, &irq_domain_list, link) {
+			if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) {
+				mutex_unlock(&irq_domain_mutex);
+				of_node_put(host->of_node);
+				kfree(host);
+				return NULL;
+			}
+		}
+	}
+	list_add(&host->link, &irq_domain_list);
+	mutex_unlock(&irq_domain_mutex);
+
+	/* Additional setups per revmap type */
+	switch(revmap_type) {
+	case IRQ_DOMAIN_MAP_LEGACY:
+		/* 0 is always the invalid number for legacy */
+		host->inval_irq = 0;
+		/* setup us as the host for all legacy interrupts */
+		for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
+			struct irq_data *irq_data = irq_get_irq_data(i);
+			irq_data->hwirq = i;
+			irq_data->domain = host;
+
+			/* Legacy flags are left to default at this point,
+			 * one can then use irq_create_mapping() to
+			 * explicitly change them
+			 */
+			ops->map(host, i, i);
+
+			/* Clear norequest flags */
+			irq_clear_status_flags(i, IRQ_NOREQUEST);
+		}
+		break;
+	case IRQ_DOMAIN_MAP_LINEAR:
+		rmap = (unsigned int *)(host + 1);
+		for (i = 0; i < revmap_arg; i++)
+			rmap[i] = NO_IRQ;
+		host->revmap_data.linear.size = revmap_arg;
+		host->revmap_data.linear.revmap = rmap;
+		break;
+	case IRQ_DOMAIN_MAP_TREE:
+		INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
+		break;
+	default:
+		break;
+	}
+
+	pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
+
+	return host;
+}
+
+/**
+ * irq_find_host() - Locates a domain for a given device node
+ * @node: device-tree node of the interrupt controller
+ */
+struct irq_domain *irq_find_host(struct device_node *node)
+{
+	struct irq_domain *h, *found = NULL;
+
+	/* 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...
+	 */
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(h, &irq_domain_list, link)
+		if (h->ops->match(h, node)) {
+			found = h;
+			break;
+		}
+	mutex_unlock(&irq_domain_mutex);
+	return found;
+}
+EXPORT_SYMBOL_GPL(irq_find_host);
+
+/**
+ * irq_set_default_host() - Set a "default" irq domain
+ * @host: default host 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 *host)
+{
+	pr_debug("irq: Default host set to @0x%p\n", host);
+
+	irq_default_host = host;
+}
+
+/**
+ * irq_set_virq_count() - Set the maximum number of linux irqs
+ * @count: number of linux irqs, capped with NR_IRQS
+ *
+ * This is mainly for use by platforms like iSeries who want to program
+ * the virtual irq number in the controller to avoid the reverse mapping
+ */
+void irq_set_virq_count(unsigned int count)
+{
+	pr_debug("irq: Trying to set virq count to %d\n", count);
+
+	BUG_ON(count < NUM_ISA_INTERRUPTS);
+	if (count < NR_IRQS)
+		irq_virq_count = count;
+}
+
+static int irq_setup_virq(struct irq_domain *host, unsigned int virq,
+			    irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+
+	irq_data->hwirq = hwirq;
+	irq_data->domain = host;
+	if (host->ops->map(host, virq, hwirq)) {
+		pr_debug("irq: -> mapping failed, freeing\n");
+		irq_data->domain = NULL;
+		irq_data->hwirq = 0;
+		return -1;
+	}
+
+	irq_clear_status_flags(virq, IRQ_NOREQUEST);
+
+	return 0;
+}
+
+/**
+ * irq_create_direct_mapping() - Allocate an irq for direct mapping
+ * @host: domain to allocate the irq for or NULL for default host
+ *
+ * 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.
+ */
+unsigned int irq_create_direct_mapping(struct irq_domain *host)
+{
+	unsigned int virq;
+
+	if (host == NULL)
+		host = irq_default_host;
+
+	BUG_ON(host == NULL);
+	WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
+
+	virq = irq_alloc_desc_from(1, 0);
+	if (virq == NO_IRQ) {
+		pr_debug("irq: create_direct virq allocation failed\n");
+		return NO_IRQ;
+	}
+	if (virq >= irq_virq_count) {
+		pr_err("ERROR: no free irqs available below %i maximum\n",
+			irq_virq_count);
+		irq_free_desc(virq);
+		return 0;
+	}
+
+	pr_debug("irq: create_direct obtained virq %d\n", virq);
+
+	if (irq_setup_virq(host, virq, virq)) {
+		irq_free_desc(virq);
+		return NO_IRQ;
+	}
+
+	return virq;
+}
+
+/**
+ * irq_create_mapping() - Map a hardware interrupt into linux irq space
+ * @host: host owning this hardware interrupt or NULL for default host
+ * @hwirq: hardware irq number in that host 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 *host,
+				irq_hw_number_t hwirq)
+{
+	unsigned int virq, hint;
+
+	pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
+
+	/* Look for default host if nececssary */
+	if (host == NULL)
+		host = irq_default_host;
+	if (host == NULL) {
+		printk(KERN_WARNING "irq_create_mapping called for"
+		       " NULL host, hwirq=%lx\n", hwirq);
+		WARN_ON(1);
+		return NO_IRQ;
+	}
+	pr_debug("irq: -> using host @%p\n", host);
+
+	/* Check if mapping already exists */
+	virq = irq_find_mapping(host, hwirq);
+	if (virq != NO_IRQ) {
+		pr_debug("irq: -> existing mapping on virq %d\n", virq);
+		return virq;
+	}
+
+	/* Get a virtual interrupt number */
+	if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
+		/* Handle legacy */
+		virq = (unsigned int)hwirq;
+		if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
+			return NO_IRQ;
+		return virq;
+	} else {
+		/* Allocate a virtual interrupt number */
+		hint = hwirq % irq_virq_count;
+		if (hint == 0)
+			hint++;
+		virq = irq_alloc_desc_from(hint, 0);
+		if (!virq)
+			virq = irq_alloc_desc_from(1, 0);
+		if (virq == NO_IRQ) {
+			pr_debug("irq: -> virq allocation failed\n");
+			return NO_IRQ;
+		}
+	}
+
+	if (irq_setup_virq(host, virq, hwirq)) {
+		if (host->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
+			irq_free_desc(virq);
+		return NO_IRQ;
+	}
+
+	pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
+		hwirq, host->of_node ? host->of_node->full_name : "null", virq);
+
+	return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_mapping);
+
+unsigned int irq_create_of_mapping(struct device_node *controller,
+				   const u32 *intspec, unsigned int intsize)
+{
+	struct irq_domain *host;
+	irq_hw_number_t hwirq;
+	unsigned int type = IRQ_TYPE_NONE;
+	unsigned int virq;
+
+	if (controller == NULL)
+		host = irq_default_host;
+	else
+		host = irq_find_host(controller);
+	if (host == NULL) {
+		printk(KERN_WARNING "irq: no irq host found for %s !\n",
+		       controller->full_name);
+		return NO_IRQ;
+	}
+
+	/* If host has no translation, then we assume interrupt line */
+	if (host->ops->xlate == NULL)
+		hwirq = intspec[0];
+	else {
+		if (host->ops->xlate(host, controller, intspec, intsize,
+				     &hwirq, &type))
+			return NO_IRQ;
+	}
+
+	/* Create mapping */
+	virq = irq_create_mapping(host, hwirq);
+	if (virq == NO_IRQ)
+		return virq;
+
+	/* Set type if specified and different than the current one */
+	if (type != IRQ_TYPE_NONE &&
+	    type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
+		irq_set_irq_type(virq, type);
+	return virq;
+}
+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 *host;
+	irq_hw_number_t hwirq;
+
+	if (virq == NO_IRQ || !irq_data)
+		return;
+
+	host = irq_data->domain;
+	if (WARN_ON(host == NULL))
+		return;
+
+	/* Never unmap legacy interrupts */
+	if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+		return;
+
+	irq_set_status_flags(virq, IRQ_NOREQUEST);
+
+	/* remove chip and handler */
+	irq_set_chip_and_handler(virq, NULL, NULL);
+
+	/* Make sure it's completed */
+	synchronize_irq(virq);
+
+	/* Tell the PIC about it */
+	if (host->ops->unmap)
+		host->ops->unmap(host, virq);
+	smp_mb();
+
+	/* Clear reverse map */
+	hwirq = irq_data->hwirq;
+	switch(host->revmap_type) {
+	case IRQ_DOMAIN_MAP_LINEAR:
+		if (hwirq < host->revmap_data.linear.size)
+			host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
+		break;
+	case IRQ_DOMAIN_MAP_TREE:
+		mutex_lock(&revmap_trees_mutex);
+		radix_tree_delete(&host->revmap_data.tree, hwirq);
+		mutex_unlock(&revmap_trees_mutex);
+		break;
+	}
+
+	/* Destroy map */
+	irq_data->hwirq = host->inval_irq;
+
+	irq_free_desc(virq);
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+
+/**
+ * irq_find_mapping() - Find a linux irq from an hw irq number.
+ * @host: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that host space
+ *
+ * This is a slow path, for use by generic code. It's expected that an
+ * irq controller implementation directly calls the appropriate low level
+ * mapping function.
+ */
+unsigned int irq_find_mapping(struct irq_domain *host,
+			      irq_hw_number_t hwirq)
+{
+	unsigned int i;
+	unsigned int hint = hwirq % irq_virq_count;
+
+	/* Look for default host if nececssary */
+	if (host == NULL)
+		host = irq_default_host;
+	if (host == NULL)
+		return NO_IRQ;
+
+	/* legacy -> bail early */
+	if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+		return hwirq;
+
+	/* Slow path does a linear search of the map */
+	if (hint == 0)
+		hint = 1;
+	i = hint;
+	do {
+		struct irq_data *data = irq_get_irq_data(i);
+		if (data && (data->domain == host) && (data->hwirq == hwirq))
+			return i;
+		i++;
+		if (i >= irq_virq_count)
+			i = 1;
+	} while(i != hint);
+	return NO_IRQ;
+}
+EXPORT_SYMBOL_GPL(irq_find_mapping);
+
+/**
+ * irq_radix_revmap_lookup() - Find a linux irq from a hw irq number.
+ * @host: host owning this hardware interrupt
+ * @hwirq: hardware irq number in that host space
+ *
+ * This is a fast path, for use by irq controller code that uses radix tree
+ * revmaps
+ */
+unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
+				     irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data;
+
+	if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
+		return irq_find_mapping(host, hwirq);
+
+	/*
+	 * Freeing an irq can delete nodes along the path to
+	 * do the lookup via call_rcu.
+	 */
+	rcu_read_lock();
+	irq_data = radix_tree_lookup(&host->revmap_data.tree, hwirq);
+	rcu_read_unlock();
+
+	/*
+	 * If found in radix tree, then fine.
+	 * Else fallback to linear lookup - this should not happen in practice
+	 * as it means that we failed to insert the node in the radix tree.
+	 */
+	return irq_data ? irq_data->irq : irq_find_mapping(host, hwirq);
+}
+
+/**
+ * irq_radix_revmap_insert() - Insert a hw irq to linux irq number mapping.
+ * @host: host owning this hardware interrupt
+ * @virq: linux irq number
+ * @hwirq: hardware irq number in that host space
+ *
+ * This is for use by irq controllers that use a radix tree reverse
+ * mapping for fast lookup.
+ */
+void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
+			     irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+
+	if (WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
+		return;
+
+	if (virq != NO_IRQ) {
+		mutex_lock(&revmap_trees_mutex);
+		radix_tree_insert(&host->revmap_data.tree, hwirq, irq_data);
+		mutex_unlock(&revmap_trees_mutex);
+	}
+}
+
+/**
+ * irq_linear_revmap() - Find a linux irq from a hw irq number.
+ * @host: host owning this hardware interrupt
+ * @hwirq: hardware irq number in that host space
+ *
+ * This is a fast path, for use by irq controller code that uses linear
+ * revmaps. It does fallback to the slow path if the revmap doesn't exist
+ * yet and will create the revmap entry with appropriate locking
+ */
+unsigned int irq_linear_revmap(struct irq_domain *host,
+			       irq_hw_number_t hwirq)
+{
+	unsigned int *revmap;
+
+	if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_LINEAR))
+		return irq_find_mapping(host, hwirq);
+
+	/* Check revmap bounds */
+	if (unlikely(hwirq >= host->revmap_data.linear.size))
+		return irq_find_mapping(host, hwirq);
+
+	/* Check if revmap was allocated */
+	revmap = host->revmap_data.linear.revmap;
+	if (unlikely(revmap == NULL))
+		return irq_find_mapping(host, hwirq);
+
+	/* Fill up revmap with slow path if no mapping found */
+	if (unlikely(revmap[hwirq] == NO_IRQ))
+		revmap[hwirq] = irq_find_mapping(host, hwirq);
+
+	return revmap[hwirq];
+}
+
+#ifdef CONFIG_VIRQ_DEBUG
+static int virq_debug_show(struct seq_file *m, void *private)
+{
+	unsigned long flags;
+	struct irq_desc *desc;
+	const char *p;
+	static const char none[] = "none";
+	void *data;
+	int i;
+
+	seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
+		      "chip name", "chip data", "host name");
+
+	for (i = 1; i < nr_irqs; i++) {
+		desc = irq_to_desc(i);
+		if (!desc)
+			continue;
+
+		raw_spin_lock_irqsave(&desc->lock, flags);
+
+		if (desc->action && desc->action->handler) {
+			struct irq_chip *chip;
+
+			seq_printf(m, "%5d  ", i);
+			seq_printf(m, "0x%05lx  ", desc->irq_data.hwirq);
+
+			chip = irq_desc_get_chip(desc);
+			if (chip && chip->name)
+				p = chip->name;
+			else
+				p = none;
+			seq_printf(m, "%-15s  ", p);
+
+			data = irq_desc_get_chip_data(desc);
+			seq_printf(m, "0x%16p  ", data);
+
+			if (desc->irq_data.domain->of_node)
+				p = desc->irq_data.domain->of_node->full_name;
+			else
+				p = none;
+			seq_printf(m, "%s\n", p);
+		}
+
+		raw_spin_unlock_irqrestore(&desc->lock, flags);
+	}
+
+	return 0;
+}
+
+static int virq_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, virq_debug_show, inode->i_private);
+}
+
+static const struct file_operations virq_debug_fops = {
+	.open = virq_debug_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int __init irq_debugfs_init(void)
+{
+	if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
+				 NULL, &virq_debug_fops) == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+__initcall(irq_debugfs_init);
+#endif /* CONFIG_VIRQ_DEBUG */
+
+#else /* CONFIG_PPC */
+
 /**
  * irq_domain_add() - Register an irq_domain
  * @domain: ptr to initialized irq_domain structure
@@ -185,3 +783,5 @@ struct irq_domain_ops irq_domain_simple_ops = {
 #endif /* CONFIG_OF_IRQ */
 };
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
+
+#endif /* !CONFIG_PPC */