linux/kernel/irq/irqdomain.c

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#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
*
* Registers an irq_domain structure. The irq_domain must at a minimum be
* initialized with an ops structure pointer, and either a ->to_irq hook or
* a valid irq_base value. Everything else is optional.
*/
void irq_domain_add(struct irq_domain *domain)
{
struct irq_data *d;
int hwirq, irq;
/*
* This assumes that the irq_domain owner has already allocated
* the irq_descs. This block will be removed when support for dynamic
* allocation of irq_descs is added to irq_domain.
*/
irq_domain_for_each_irq(domain, hwirq, irq) {
d = irq_get_irq_data(irq);
if (!d) {
WARN(1, "error: assigning domain to non existant irq_desc");
return;
}
if (d->domain) {
/* things are broken; just report, don't clean up */
WARN(1, "error: irq_desc already assigned to a domain");
return;
}
d->domain = domain;
d->hwirq = hwirq;
}
mutex_lock(&irq_domain_mutex);
list_add(&domain->link, &irq_domain_list);
mutex_unlock(&irq_domain_mutex);
}
/**
* irq_domain_del() - Unregister an irq_domain
* @domain: ptr to registered irq_domain.
*/
void irq_domain_del(struct irq_domain *domain)
{
struct irq_data *d;
int hwirq, irq;
mutex_lock(&irq_domain_mutex);
list_del(&domain->link);
mutex_unlock(&irq_domain_mutex);
/* Clear the irq_domain assignments */
irq_domain_for_each_irq(domain, hwirq, irq) {
d = irq_get_irq_data(irq);
d->domain = NULL;
}
}
#if defined(CONFIG_OF_IRQ)
/**
* irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
*
* Used by the device tree interrupt mapping code to translate a device tree
* interrupt specifier to a valid linux irq number. Returns either a valid
* linux IRQ number or 0.
*
* When the caller no longer need the irq number returned by this function it
* should arrange to call irq_dispose_mapping().
*/
unsigned int irq_create_of_mapping(struct device_node *controller,
const u32 *intspec, unsigned int intsize)
{
struct irq_domain *domain;
unsigned long hwirq;
unsigned int irq, type;
int rc = -EINVAL;
/* Find a domain which can translate the irq spec */
mutex_lock(&irq_domain_mutex);
list_for_each_entry(domain, &irq_domain_list, link) {
if (!domain->ops->xlate)
continue;
rc = domain->ops->xlate(domain, controller,
intspec, intsize, &hwirq, &type);
if (rc == 0)
break;
}
mutex_unlock(&irq_domain_mutex);
if (rc != 0)
return 0;
irq = irq_domain_to_irq(domain, hwirq);
if (type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, type);
pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
controller->full_name, (int)hwirq, irq, type);
return irq;
}
EXPORT_SYMBOL_GPL(irq_create_of_mapping);
/**
* irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
* @irq: linux irq number to be discarded
*
* Calling this function indicates the caller no longer needs a reference to
* the linux irq number returned by a prior call to irq_create_of_mapping().
*/
void irq_dispose_mapping(unsigned int irq)
{
/*
* nothing yet; will be filled when support for dynamic allocation of
* irq_descs is added to irq_domain
*/
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);
int irq_domain_simple_xlate(struct irq_domain *d,
struct device_node *controller,
const u32 *intspec, unsigned int intsize,
unsigned long *out_hwirq, unsigned int *out_type)
{
if (d->of_node != controller)
return -EINVAL;
if (intsize < 1)
return -EINVAL;
if (d->nr_irq && ((intspec[0] < d->hwirq_base) ||
(intspec[0] >= d->hwirq_base + d->nr_irq)))
return -EINVAL;
*out_hwirq = intspec[0];
*out_type = IRQ_TYPE_NONE;
if (intsize > 1)
*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
return 0;
}
/**
* irq_domain_create_simple() - Set up a 'simple' translation range
*/
void irq_domain_add_simple(struct device_node *controller, int irq_base)
{
struct irq_domain *domain;
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!domain) {
WARN_ON(1);
return;
}
domain->irq_base = irq_base;
domain->of_node = of_node_get(controller);
domain->ops = &irq_domain_simple_ops;
irq_domain_add(domain);
}
EXPORT_SYMBOL_GPL(irq_domain_add_simple);
void irq_domain_generate_simple(const struct of_device_id *match,
u64 phys_base, unsigned int irq_start)
{
struct device_node *node;
pr_debug("looking for phys_base=%llx, irq_start=%i\n",
(unsigned long long) phys_base, (int) irq_start);
node = of_find_matching_node_by_address(NULL, match, phys_base);
if (node)
irq_domain_add_simple(node, irq_start);
}
EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
#endif /* CONFIG_OF_IRQ */
struct irq_domain_ops irq_domain_simple_ops = {
#ifdef CONFIG_OF_IRQ
.xlate = irq_domain_simple_xlate,
#endif /* CONFIG_OF_IRQ */
};
EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
#endif /* !CONFIG_PPC */