Linux preempt-rt

Check our new training course

Real-Time Linux with PREEMPT_RT

Check our new training course
with Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

/* SPDX-License-Identifier: GPL-2.0 */

#include <linux/rcupdate.h>
#include <linux/kobject.h>
#include <linux/mutex.h>

 * Core internal functions to deal with irq descriptors

struct irq_affinity_notify;
struct proc_dir_entry;
struct module;
struct irq_desc;
struct irq_domain;
struct pt_regs;

 * struct irq_desc - interrupt descriptor
 * @irq_common_data:	per irq and chip data passed down to chip functions
 * @kstat_irqs:		irq stats per cpu
 * @handle_irq:		highlevel irq-events handler
 * @action:		the irq action chain
 * @status_use_accessors: status information
 * @core_internal_state__do_not_mess_with_it: core internal status information
 * @depth:		disable-depth, for nested irq_disable() calls
 * @wake_depth:		enable depth, for multiple irq_set_irq_wake() callers
 * @tot_count:		stats field for non-percpu irqs
 * @irq_count:		stats field to detect stalled irqs
 * @last_unhandled:	aging timer for unhandled count
 * @irqs_unhandled:	stats field for spurious unhandled interrupts
 * @threads_handled:	stats field for deferred spurious detection of threaded handlers
 * @threads_handled_last: comparator field for deferred spurious detection of threaded handlers
 * @lock:		locking for SMP
 * @affinity_hint:	hint to user space for preferred irq affinity
 * @affinity_notify:	context for notification of affinity changes
 * @pending_mask:	pending rebalanced interrupts
 * @threads_oneshot:	bitfield to handle shared oneshot threads
 * @threads_active:	number of irqaction threads currently running
 * @wait_for_threads:	wait queue for sync_irq to wait for threaded handlers
 * @nr_actions:		number of installed actions on this descriptor
 * @no_suspend_depth:	number of irqactions on a irq descriptor with
 * @force_resume_depth:	number of irqactions on a irq descriptor with
 * @rcu:		rcu head for delayed free
 * @kobj:		kobject used to represent this struct in sysfs
 * @request_mutex:	mutex to protect request/free before locking desc->lock
 * @dir:		/proc/irq/ procfs entry
 * @debugfs_file:	dentry for the debugfs file
 * @name:		flow handler name for /proc/interrupts output
struct irq_desc {
	struct irq_common_data	irq_common_data;
	struct irq_data		irq_data;
	unsigned int __percpu	*kstat_irqs;
	irq_flow_handler_t	handle_irq;
	struct irqaction	*action;	/* IRQ action list */
	unsigned int		status_use_accessors;
	unsigned int		core_internal_state__do_not_mess_with_it;
	unsigned int		depth;		/* nested irq disables */
	unsigned int		wake_depth;	/* nested wake enables */
	unsigned int		tot_count;
	unsigned int		irq_count;	/* For detecting broken IRQs */
	unsigned long		last_unhandled;	/* Aging timer for unhandled count */
	unsigned int		irqs_unhandled;
	atomic_t		threads_handled;
	int			threads_handled_last;
	raw_spinlock_t		lock;
	struct cpumask		*percpu_enabled;
	const struct cpumask	*percpu_affinity;
	const struct cpumask	*affinity_hint;
	struct irq_affinity_notify *affinity_notify;
	cpumask_var_t		pending_mask;
	unsigned long		threads_oneshot;
	atomic_t		threads_active;
	wait_queue_head_t       wait_for_threads;
	unsigned int		nr_actions;
	unsigned int		no_suspend_depth;
	unsigned int		cond_suspend_depth;
	unsigned int		force_resume_depth;
	struct proc_dir_entry	*dir;
	struct dentry		*debugfs_file;
	const char		*dev_name;
	struct rcu_head		rcu;
	struct kobject		kobj;
	struct mutex		request_mutex;
	int			parent_irq;
	struct module		*owner;
	const char		*name;
} ____cacheline_internodealigned_in_smp;

extern void irq_lock_sparse(void);
extern void irq_unlock_sparse(void);
static inline void irq_lock_sparse(void) { }
static inline void irq_unlock_sparse(void) { }
extern struct irq_desc irq_desc[NR_IRQS];

static inline unsigned int irq_desc_kstat_cpu(struct irq_desc *desc,
					      unsigned int cpu)
	return desc->kstat_irqs ? *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;

static inline struct irq_desc *irq_data_to_desc(struct irq_data *data)
	return container_of(data->common, struct irq_desc, irq_common_data);

static inline unsigned int irq_desc_get_irq(struct irq_desc *desc)
	return desc->irq_data.irq;

static inline struct irq_data *irq_desc_get_irq_data(struct irq_desc *desc)
	return &desc->irq_data;

static inline struct irq_chip *irq_desc_get_chip(struct irq_desc *desc)
	return desc->irq_data.chip;

static inline void *irq_desc_get_chip_data(struct irq_desc *desc)
	return desc->irq_data.chip_data;

static inline void *irq_desc_get_handler_data(struct irq_desc *desc)
	return desc->irq_common_data.handler_data;

 * Architectures call this to let the generic IRQ layer
 * handle an interrupt.
static inline void generic_handle_irq_desc(struct irq_desc *desc)

int handle_irq_desc(struct irq_desc *desc);
int generic_handle_irq(unsigned int irq);
int generic_handle_irq_safe(unsigned int irq);

 * Convert a HW interrupt number to a logical one using a IRQ domain,
 * and handle the result interrupt number. Return -EINVAL if
 * conversion failed.
int generic_handle_domain_irq(struct irq_domain *domain, unsigned int hwirq);
int generic_handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq);

/* Test to see if a driver has successfully requested an irq */
static inline int irq_desc_has_action(struct irq_desc *desc)
	return desc && desc->action != NULL;

 * irq_set_handler_locked - Set irq handler from a locked region
 * @data:	Pointer to the irq_data structure which identifies the irq
 * @handler:	Flow control handler function for this interrupt
 * Sets the handler in the irq descriptor associated to @data.
 * Must be called with irq_desc locked and valid parameters. Typical
 * call site is the irq_set_type() callback.
static inline void irq_set_handler_locked(struct irq_data *data,
					  irq_flow_handler_t handler)
	struct irq_desc *desc = irq_data_to_desc(data);

	desc->handle_irq = handler;

 * irq_set_chip_handler_name_locked - Set chip, handler and name from a locked region
 * @data:	Pointer to the irq_data structure for which the chip is set
 * @chip:	Pointer to the new irq chip
 * @handler:	Flow control handler function for this interrupt
 * @name:	Name of the interrupt
 * Replace the irq chip at the proper hierarchy level in @data and
 * sets the handler and name in the associated irq descriptor.
 * Must be called with irq_desc locked and valid parameters.
static inline void
irq_set_chip_handler_name_locked(struct irq_data *data, struct irq_chip *chip,
				 irq_flow_handler_t handler, const char *name)
	struct irq_desc *desc = irq_data_to_desc(data);

	desc->handle_irq = handler;
	desc->name = name;
	data->chip = chip;

bool irq_check_status_bit(unsigned int irq, unsigned int bitmask);

static inline bool irq_balancing_disabled(unsigned int irq)
	return irq_check_status_bit(irq, IRQ_NO_BALANCING_MASK);

static inline bool irq_is_percpu(unsigned int irq)
	return irq_check_status_bit(irq, IRQ_PER_CPU);

static inline bool irq_is_percpu_devid(unsigned int irq)
	return irq_check_status_bit(irq, IRQ_PER_CPU_DEVID);

void __irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
			     struct lock_class_key *request_class);
static inline void
irq_set_lockdep_class(unsigned int irq, struct lock_class_key *lock_class,
		      struct lock_class_key *request_class)
		__irq_set_lockdep_class(irq, lock_class, request_class);