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>
#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
* ie. legacy 8259, gets irqs 1..15 */
#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
static LIST_HEAD(irq_domain_list);
static DEFINE_MUTEX(irq_domain_mutex);
static DEFINE_MUTEX(revmap_trees_mutex);
static unsigned int irq_virq_count = NR_IRQS;
static struct irq_domain *irq_default_domain;
/**
* irq_domain_alloc() - 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
* @ops: map/unmap domain callbacks
* @host_data: Controller private data pointer
*
* Allocates and initialize and irq_domain structure. Caller is expected to
* register allocated irq_domain with irq_domain_register(). Returns pointer
* to IRQ domain, or NULL on failure.
*/
static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
unsigned int revmap_type,
const struct irq_domain_ops *ops,
void *host_data)
{
struct irq_domain *domain;
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (WARN_ON(!domain))
return NULL;
/* Fill structure */
domain->revmap_type = revmap_type;
domain->ops = ops;
domain->host_data = host_data;
domain->of_node = of_node_get(of_node);
return domain;
}
static void irq_domain_add(struct irq_domain *domain)
{
mutex_lock(&irq_domain_mutex);
list_add(&domain->link, &irq_domain_list);
mutex_unlock(&irq_domain_mutex);
pr_debug("irq: Allocated domain of type %d @0x%p\n",
domain->revmap_type, domain);
}
static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
irq_hw_number_t hwirq)
{
irq_hw_number_t first_hwirq = domain->revmap_data.legacy.first_hwirq;
int size = domain->revmap_data.legacy.size;
if (WARN_ON(hwirq < first_hwirq || hwirq >= first_hwirq + size))
return 0;
return hwirq - first_hwirq + domain->revmap_data.legacy.first_irq;
}
/**
* 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;
unsigned int i;
domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
if (!domain)
return NULL;
domain->revmap_data.legacy.first_irq = first_irq;
domain->revmap_data.legacy.first_hwirq = first_hwirq;
domain->revmap_data.legacy.size = size;
mutex_lock(&irq_domain_mutex);
/* Verify that all the irqs are available */
for (i = 0; i < size; i++) {
int irq = first_irq + i;
struct irq_data *irq_data = irq_get_irq_data(irq);
if (WARN_ON(!irq_data || irq_data->domain)) {
mutex_unlock(&irq_domain_mutex);
of_node_put(domain->of_node);
kfree(domain);
return NULL;
}
}
/* Claim all of the irqs before registering a legacy domain */
for (i = 0; i < size; i++) {
struct irq_data *irq_data = irq_get_irq_data(first_irq + i);
irq_data->hwirq = first_hwirq + i;
irq_data->domain = domain;
}
mutex_unlock(&irq_domain_mutex);
for (i = 0; i < size; i++) {
int irq = first_irq + i;
int hwirq = first_hwirq + i;
/* IRQ0 gets ignored */
if (!irq)
continue;
/* Legacy flags are left to default at this point,
* one can then use irq_create_mapping() to
* explicitly change them
*/
ops->map(domain, irq, hwirq);
/* Clear norequest flags */
irq_clear_status_flags(irq, IRQ_NOREQUEST);
}
irq_domain_add(domain);
return domain;
}
/**
* irq_domain_add_linear() - Allocate and register a legacy revmap irq_domain.
* @of_node: pointer to interrupt controller's device tree node.
* @ops: map/unmap domain callbacks
* @host_data: Controller private data pointer
*/
struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
unsigned int size,
const struct irq_domain_ops *ops,
void *host_data)
{
struct irq_domain *domain;
unsigned int *revmap;
revmap = kzalloc(sizeof(*revmap) * size, GFP_KERNEL);
if (WARN_ON(!revmap))
return NULL;
domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LINEAR, ops, host_data);
if (!domain) {
kfree(revmap);
return NULL;
}
domain->revmap_data.linear.size = size;
domain->revmap_data.linear.revmap = revmap;
irq_domain_add(domain);
return domain;
}
struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
const struct irq_domain_ops *ops,
void *host_data)
{
struct irq_domain *domain = irq_domain_alloc(of_node,
IRQ_DOMAIN_MAP_NOMAP, ops, host_data);
if (domain)
irq_domain_add(domain);
return domain;
}
/**
* irq_domain_add_tree()
* @of_node: pointer to interrupt controller's device tree node.
* @ops: map/unmap domain callbacks
*
* Note: 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_domain_add_tree(struct device_node *of_node,
const struct irq_domain_ops *ops,
void *host_data)
{
struct irq_domain *domain = irq_domain_alloc(of_node,
IRQ_DOMAIN_MAP_TREE, ops, host_data);
if (domain) {
INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
irq_domain_add(domain);
}
return domain;
}
/**
* 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;
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...
*/
mutex_lock(&irq_domain_mutex);
list_for_each_entry(h, &irq_domain_list, link) {
if (h->ops->match)
rc = h->ops->match(h, node);
else
rc = (h->of_node != NULL) && (h->of_node == node);
if (rc) {
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
* @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("irq: Default domain set to @0x%p\n", domain);
irq_default_domain = domain;
}
/**
* 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 *domain, 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 = domain;
if (domain->ops->map(domain, 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
* @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.
*/
unsigned int irq_create_direct_mapping(struct irq_domain *domain)
{
unsigned int virq;
if (domain == NULL)
domain = irq_default_domain;
BUG_ON(domain == NULL);
WARN_ON(domain->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
virq = irq_alloc_desc_from(1, 0);
if (!virq) {
pr_debug("irq: create_direct virq allocation failed\n");
return 0;
}
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(domain, virq, virq)) {
irq_free_desc(virq);
return 0;
}
return virq;
}
/**
* 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)
{
unsigned int virq, hint;
pr_debug("irq: 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) {
printk(KERN_WARNING "irq_create_mapping called for"
" NULL domain, hwirq=%lx\n", hwirq);
WARN_ON(1);
return 0;
}
pr_debug("irq: -> using domain @%p\n", domain);
/* Check if mapping already exists */
virq = irq_find_mapping(domain, hwirq);
if (virq) {
pr_debug("irq: -> existing mapping on virq %d\n", virq);
return virq;
}
/* Get a virtual interrupt number */
if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
return irq_domain_legacy_revmap(domain, hwirq);
/* 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) {
pr_debug("irq: -> virq allocation failed\n");
return 0;
}
if (irq_setup_virq(domain, virq, hwirq)) {
if (domain->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
irq_free_desc(virq);
return 0;
}
pr_debug("irq: irq %lu on domain %s mapped to virtual irq %u\n",
hwirq, domain->of_node ? domain->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 *domain;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
unsigned int virq;
domain = controller ? irq_find_host(controller) : irq_default_domain;
if (!domain) {
#ifdef CONFIG_MIPS
/*
* Workaround to avoid breaking interrupt controller drivers
* that don't yet register an irq_domain. This is temporary
* code. ~~~gcl, Feb 24, 2012
*
* Scheduled for removal in Linux v3.6. That should be enough
* time.
*/
if (intsize > 0)
return intspec[0];
#endif
printk(KERN_WARNING "irq: no irq domain found for %s !\n",
controller->full_name);
return 0;
}
/* If domain has no translation, then we assume interrupt line */
if (domain->ops->xlate == NULL)
hwirq = intspec[0];
else {
if (domain->ops->xlate(domain, controller, intspec, intsize,
&hwirq, &type))
return 0;
}
/* Create mapping */
virq = irq_create_mapping(domain, hwirq);
if (!virq)
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 *domain;
irq_hw_number_t hwirq;
if (!virq || !irq_data)
return;
domain = irq_data->domain;
if (WARN_ON(domain == NULL))
return;
/* Never unmap legacy interrupts */
if (domain->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 (domain->ops->unmap)
domain->ops->unmap(domain, virq);
smp_mb();
/* Clear reverse map */
hwirq = irq_data->hwirq;
switch(domain->revmap_type) {
case IRQ_DOMAIN_MAP_LINEAR:
if (hwirq < domain->revmap_data.linear.size)
domain->revmap_data.linear.revmap[hwirq] = 0;
break;
case IRQ_DOMAIN_MAP_TREE:
mutex_lock(&revmap_trees_mutex);
radix_tree_delete(&domain->revmap_data.tree, hwirq);
mutex_unlock(&revmap_trees_mutex);
break;
}
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
*
* 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 *domain,
irq_hw_number_t hwirq)
{
unsigned int i;
unsigned int hint = hwirq % irq_virq_count;
/* Look for default domain if nececssary */
if (domain == NULL)
domain = irq_default_domain;
if (domain == NULL)
return 0;
/* legacy -> bail early */
if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
return irq_domain_legacy_revmap(domain, 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 == domain) && (data->hwirq == hwirq))
return i;
i++;
if (i >= irq_virq_count)
i = 1;
} while(i != hint);
return 0;
}
EXPORT_SYMBOL_GPL(irq_find_mapping);
/**
* irq_radix_revmap_lookup() - Find a linux irq from a hw irq number.
* @domain: domain owning this hardware interrupt
* @hwirq: hardware irq number in that domain 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 *domain,
irq_hw_number_t hwirq)
{
struct irq_data *irq_data;
if (WARN_ON_ONCE(domain->revmap_type != IRQ_DOMAIN_MAP_TREE))
return irq_find_mapping(domain, 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(&domain->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(domain, hwirq);
}
/**
* irq_radix_revmap_insert() - Insert a hw irq to linux irq number mapping.
* @domain: domain owning this hardware interrupt
* @virq: linux irq number
* @hwirq: hardware irq number in that domain 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 *domain, unsigned int virq,
irq_hw_number_t hwirq)
{
struct irq_data *irq_data = irq_get_irq_data(virq);
if (WARN_ON(domain->revmap_type != IRQ_DOMAIN_MAP_TREE))
return;
if (virq) {
mutex_lock(&revmap_trees_mutex);
radix_tree_insert(&domain->revmap_data.tree, hwirq, irq_data);
mutex_unlock(&revmap_trees_mutex);
}
}
/**
* irq_linear_revmap() - Find a linux irq from a hw irq number.
* @domain: domain owning this hardware interrupt
* @hwirq: hardware irq number in that domain 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 *domain,
irq_hw_number_t hwirq)
{
unsigned int *revmap;
if (WARN_ON_ONCE(domain->revmap_type != IRQ_DOMAIN_MAP_LINEAR))
return irq_find_mapping(domain, hwirq);
/* Check revmap bounds */
if (unlikely(hwirq >= domain->revmap_data.linear.size))
return irq_find_mapping(domain, hwirq);
/* Check if revmap was allocated */
revmap = domain->revmap_data.linear.revmap;
if (unlikely(revmap == NULL))
return irq_find_mapping(domain, hwirq);
/* Fill up revmap with slow path if no mapping found */
if (unlikely(!revmap[hwirq]))
revmap[hwirq] = irq_find_mapping(domain, 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", "domain 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 */
int irq_domain_simple_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
return 0;
}
/**
* 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];
*out_type = (intsize > 1) ? intspec[1] : IRQ_TYPE_NONE;
return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);
const struct irq_domain_ops irq_domain_simple_ops = {
.map = irq_domain_simple_map,
.xlate = irq_domain_xlate_onetwocell,
};
EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
#ifdef CONFIG_OF_IRQ
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_legacy(node, 32, irq_start, 0,
&irq_domain_simple_ops, NULL);
}
EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
#endif