linux/kernel/irq/chip.c

// 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 core interrupt handling code, for irq-chip based
 * architectures. Detailed information is available in
 * Documentation/core-api/genericirq.rst
 */

#include <linux/irq.h>
#include <linux/msi.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/irqdomain.h>

#include <trace/events/irq.h>

#include "internals.h"

static irqreturn_t bad_chained_irq(int irq, void *dev_id)
{ … }

/*
 * Chained handlers should never call action on their IRQ. This default
 * action will emit warning if such thing happens.
 */
struct irqaction chained_action = …;

/**
 *	irq_set_chip - set the irq chip for an irq
 *	@irq:	irq number
 *	@chip:	pointer to irq chip description structure
 */
int irq_set_chip(unsigned int irq, const struct irq_chip *chip)
{ … }
EXPORT_SYMBOL(…);

/**
 *	irq_set_irq_type - set the irq trigger type for an irq
 *	@irq:	irq number
 *	@type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
 */
int irq_set_irq_type(unsigned int irq, unsigned int type)
{ … }
EXPORT_SYMBOL(…);

/**
 *	irq_set_handler_data - set irq handler data for an irq
 *	@irq:	Interrupt number
 *	@data:	Pointer to interrupt specific data
 *
 *	Set the hardware irq controller data for an irq
 */
int irq_set_handler_data(unsigned int irq, void *data)
{ … }
EXPORT_SYMBOL(…);

/**
 *	irq_set_msi_desc_off - set MSI descriptor data for an irq at offset
 *	@irq_base:	Interrupt number base
 *	@irq_offset:	Interrupt number offset
 *	@entry:		Pointer to MSI descriptor data
 *
 *	Set the MSI descriptor entry for an irq at offset
 */
int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
			 struct msi_desc *entry)
{ … }

/**
 *	irq_set_msi_desc - set MSI descriptor data for an irq
 *	@irq:	Interrupt number
 *	@entry:	Pointer to MSI descriptor data
 *
 *	Set the MSI descriptor entry for an irq
 */
int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
{ … }

/**
 *	irq_set_chip_data - set irq chip data for an irq
 *	@irq:	Interrupt number
 *	@data:	Pointer to chip specific data
 *
 *	Set the hardware irq chip data for an irq
 */
int irq_set_chip_data(unsigned int irq, void *data)
{ … }
EXPORT_SYMBOL(…);

struct irq_data *irq_get_irq_data(unsigned int irq)
{ … }
EXPORT_SYMBOL_GPL(…);

static void irq_state_clr_disabled(struct irq_desc *desc)
{ … }

static void irq_state_clr_masked(struct irq_desc *desc)
{ … }

static void irq_state_clr_started(struct irq_desc *desc)
{ … }

static void irq_state_set_started(struct irq_desc *desc)
{ … }

enum { … };

#ifdef CONFIG_SMP
static int
__irq_startup_managed(struct irq_desc *desc, const struct cpumask *aff,
		      bool force)
{ … }
#else
static __always_inline int
__irq_startup_managed(struct irq_desc *desc, const struct cpumask *aff,
		      bool force)
{
	return IRQ_STARTUP_NORMAL;
}
#endif

static int __irq_startup(struct irq_desc *desc)
{ … }

int irq_startup(struct irq_desc *desc, bool resend, bool force)
{ … }

int irq_activate(struct irq_desc *desc)
{ … }

int irq_activate_and_startup(struct irq_desc *desc, bool resend)
{ … }

static void __irq_disable(struct irq_desc *desc, bool mask);

void irq_shutdown(struct irq_desc *desc)
{ … }


void irq_shutdown_and_deactivate(struct irq_desc *desc)
{ … }

void irq_enable(struct irq_desc *desc)
{ … }

static void __irq_disable(struct irq_desc *desc, bool mask)
{ … }

/**
 * irq_disable - Mark interrupt disabled
 * @desc:	irq descriptor which should be disabled
 *
 * If the chip does not implement the irq_disable callback, we
 * use a lazy disable approach. That means we mark the interrupt
 * disabled, but leave the hardware unmasked. That's an
 * optimization because we avoid the hardware access for the
 * common case where no interrupt happens after we marked it
 * disabled. If an interrupt happens, then the interrupt flow
 * handler masks the line at the hardware level and marks it
 * pending.
 *
 * If the interrupt chip does not implement the irq_disable callback,
 * a driver can disable the lazy approach for a particular irq line by
 * calling 'irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY)'. This can
 * be used for devices which cannot disable the interrupt at the
 * device level under certain circumstances and have to use
 * disable_irq[_nosync] instead.
 */
void irq_disable(struct irq_desc *desc)
{ … }

void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)
{ … }

void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu)
{ … }

static inline void mask_ack_irq(struct irq_desc *desc)
{ … }

void mask_irq(struct irq_desc *desc)
{ … }

void unmask_irq(struct irq_desc *desc)
{ … }

void unmask_threaded_irq(struct irq_desc *desc)
{ … }

/*
 *	handle_nested_irq - Handle a nested irq from a irq thread
 *	@irq:	the interrupt number
 *
 *	Handle interrupts which are nested into a threaded interrupt
 *	handler. The handler function is called inside the calling
 *	threads context.
 */
void handle_nested_irq(unsigned int irq)
{ … }
EXPORT_SYMBOL_GPL(…);

static bool irq_check_poll(struct irq_desc *desc)
{ … }

static bool irq_may_run(struct irq_desc *desc)
{ … }

/**
 *	handle_simple_irq - Simple and software-decoded IRQs.
 *	@desc:	the interrupt description structure for this irq
 *
 *	Simple interrupts are either sent from a demultiplexing interrupt
 *	handler or come from hardware, where no interrupt hardware control
 *	is necessary.
 *
 *	Note: The caller is expected to handle the ack, clear, mask and
 *	unmask issues if necessary.
 */
void handle_simple_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 *	handle_untracked_irq - Simple and software-decoded IRQs.
 *	@desc:	the interrupt description structure for this irq
 *
 *	Untracked interrupts are sent from a demultiplexing interrupt
 *	handler when the demultiplexer does not know which device it its
 *	multiplexed irq domain generated the interrupt. IRQ's handled
 *	through here are not subjected to stats tracking, randomness, or
 *	spurious interrupt detection.
 *
 *	Note: Like handle_simple_irq, the caller is expected to handle
 *	the ack, clear, mask and unmask issues if necessary.
 */
void handle_untracked_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * Called unconditionally from handle_level_irq() and only for oneshot
 * interrupts from handle_fasteoi_irq()
 */
static void cond_unmask_irq(struct irq_desc *desc)
{ … }

/**
 *	handle_level_irq - Level type irq handler
 *	@desc:	the interrupt description structure for this irq
 *
 *	Level type interrupts are active as long as the hardware line has
 *	the active level. This may require to mask the interrupt and unmask
 *	it after the associated handler has acknowledged the device, so the
 *	interrupt line is back to inactive.
 */
void handle_level_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
{ … }

/**
 *	handle_fasteoi_irq - irq handler for transparent controllers
 *	@desc:	the interrupt description structure for this irq
 *
 *	Only a single callback will be issued to the chip: an ->eoi()
 *	call when the interrupt has been serviced. This enables support
 *	for modern forms of interrupt handlers, which handle the flow
 *	details in hardware, transparently.
 */
void handle_fasteoi_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 *	handle_fasteoi_nmi - irq handler for NMI interrupt lines
 *	@desc:	the interrupt description structure for this irq
 *
 *	A simple NMI-safe handler, considering the restrictions
 *	from request_nmi.
 *
 *	Only a single callback will be issued to the chip: an ->eoi()
 *	call when the interrupt has been serviced. This enables support
 *	for modern forms of interrupt handlers, which handle the flow
 *	details in hardware, transparently.
 */
void handle_fasteoi_nmi(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 *	handle_edge_irq - edge type IRQ handler
 *	@desc:	the interrupt description structure for this irq
 *
 *	Interrupt occurs on the falling and/or rising edge of a hardware
 *	signal. The occurrence is latched into the irq controller hardware
 *	and must be acked in order to be reenabled. After the ack another
 *	interrupt can happen on the same source even before the first one
 *	is handled by the associated event handler. If this happens it
 *	might be necessary to disable (mask) the interrupt depending on the
 *	controller hardware. This requires to reenable the interrupt inside
 *	of the loop which handles the interrupts which have arrived while
 *	the handler was running. If all pending interrupts are handled, the
 *	loop is left.
 */
void handle_edge_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL(…);

#ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
/**
 *	handle_edge_eoi_irq - edge eoi type IRQ handler
 *	@desc:	the interrupt description structure for this irq
 *
 * Similar as the above handle_edge_irq, but using eoi and w/o the
 * mask/unmask logic.
 */
void handle_edge_eoi_irq(struct irq_desc *desc)
{
	struct irq_chip *chip = irq_desc_get_chip(desc);

	raw_spin_lock(&desc->lock);

	desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);

	if (!irq_may_run(desc)) {
		desc->istate |= IRQS_PENDING;
		goto out_eoi;
	}

	/*
	 * If its disabled or no action available then mask it and get
	 * out of here.
	 */
	if (irqd_irq_disabled(&desc->irq_data) || !desc->action) {
		desc->istate |= IRQS_PENDING;
		goto out_eoi;
	}

	kstat_incr_irqs_this_cpu(desc);

	do {
		if (unlikely(!desc->action))
			goto out_eoi;

		handle_irq_event(desc);

	} while ((desc->istate & IRQS_PENDING) &&
		 !irqd_irq_disabled(&desc->irq_data));

out_eoi:
	chip->irq_eoi(&desc->irq_data);
	raw_spin_unlock(&desc->lock);
}
#endif

/**
 *	handle_percpu_irq - Per CPU local irq handler
 *	@desc:	the interrupt description structure for this irq
 *
 *	Per CPU interrupts on SMP machines without locking requirements
 */
void handle_percpu_irq(struct irq_desc *desc)
{ … }

/**
 * handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
 * @desc:	the interrupt description structure for this irq
 *
 * Per CPU interrupts on SMP machines without locking requirements. Same as
 * handle_percpu_irq() above but with the following extras:
 *
 * action->percpu_dev_id is a pointer to percpu variables which
 * contain the real device id for the cpu on which this handler is
 * called
 */
void handle_percpu_devid_irq(struct irq_desc *desc)
{ … }

/**
 * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
 *				     dev ids
 * @desc:	the interrupt description structure for this irq
 *
 * Similar to handle_fasteoi_nmi, but handling the dev_id cookie
 * as a percpu pointer.
 */
void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc)
{ … }

static void
__irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
		     int is_chained, const char *name)
{ … }

void
__irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
		  const char *name)
{ … }
EXPORT_SYMBOL_GPL(…);

void
irq_set_chained_handler_and_data(unsigned int irq, irq_flow_handler_t handle,
				 void *data)
{ … }
EXPORT_SYMBOL_GPL(…);

void
irq_set_chip_and_handler_name(unsigned int irq, const struct irq_chip *chip,
			      irq_flow_handler_t handle, const char *name)
{ … }
EXPORT_SYMBOL_GPL(…);

void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
{ … }
EXPORT_SYMBOL_GPL(…);

#ifdef CONFIG_DEPRECATED_IRQ_CPU_ONOFFLINE
/**
 *	irq_cpu_online - Invoke all irq_cpu_online functions.
 *
 *	Iterate through all irqs and invoke the chip.irq_cpu_online()
 *	for each.
 */
void irq_cpu_online(void)
{
	struct irq_desc *desc;
	struct irq_chip *chip;
	unsigned long flags;
	unsigned int irq;

	for_each_active_irq(irq) {
		desc = irq_to_desc(irq);
		if (!desc)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);

		chip = irq_data_get_irq_chip(&desc->irq_data);
		if (chip && chip->irq_cpu_online &&
		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
		     !irqd_irq_disabled(&desc->irq_data)))
			chip->irq_cpu_online(&desc->irq_data);

		raw_spin_unlock_irqrestore(&desc->lock, flags);
	}
}

/**
 *	irq_cpu_offline - Invoke all irq_cpu_offline functions.
 *
 *	Iterate through all irqs and invoke the chip.irq_cpu_offline()
 *	for each.
 */
void irq_cpu_offline(void)
{
	struct irq_desc *desc;
	struct irq_chip *chip;
	unsigned long flags;
	unsigned int irq;

	for_each_active_irq(irq) {
		desc = irq_to_desc(irq);
		if (!desc)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);

		chip = irq_data_get_irq_chip(&desc->irq_data);
		if (chip && chip->irq_cpu_offline &&
		    (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
		     !irqd_irq_disabled(&desc->irq_data)))
			chip->irq_cpu_offline(&desc->irq_data);

		raw_spin_unlock_irqrestore(&desc->lock, flags);
	}
}
#endif

#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY

#ifdef CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS
/**
 *	handle_fasteoi_ack_irq - irq handler for edge hierarchy
 *	stacked on transparent controllers
 *
 *	@desc:	the interrupt description structure for this irq
 *
 *	Like handle_fasteoi_irq(), but for use with hierarchy where
 *	the irq_chip also needs to have its ->irq_ack() function
 *	called.
 */
void handle_fasteoi_ack_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 *	handle_fasteoi_mask_irq - irq handler for level hierarchy
 *	stacked on transparent controllers
 *
 *	@desc:	the interrupt description structure for this irq
 *
 *	Like handle_fasteoi_irq(), but for use with hierarchy where
 *	the irq_chip also needs to have its ->irq_mask_ack() function
 *	called.
 */
void handle_fasteoi_mask_irq(struct irq_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

#endif /* CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS */

/**
 * irq_chip_set_parent_state - set the state of a parent interrupt.
 *
 * @data: Pointer to interrupt specific data
 * @which: State to be restored (one of IRQCHIP_STATE_*)
 * @val: Value corresponding to @which
 *
 * Conditional success, if the underlying irqchip does not implement it.
 */
int irq_chip_set_parent_state(struct irq_data *data,
			      enum irqchip_irq_state which,
			      bool val)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_get_parent_state - get the state of a parent interrupt.
 *
 * @data: Pointer to interrupt specific data
 * @which: one of IRQCHIP_STATE_* the caller wants to know
 * @state: a pointer to a boolean where the state is to be stored
 *
 * Conditional success, if the underlying irqchip does not implement it.
 */
int irq_chip_get_parent_state(struct irq_data *data,
			      enum irqchip_irq_state which,
			      bool *state)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_enable_parent - Enable the parent interrupt (defaults to unmask if
 * NULL)
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_enable_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_disable_parent - Disable the parent interrupt (defaults to mask if
 * NULL)
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_disable_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_ack_parent - Acknowledge the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_ack_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_mask_parent - Mask the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_mask_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_mask_ack_parent - Mask and acknowledge the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_mask_ack_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_unmask_parent - Unmask the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_unmask_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_eoi_parent - Invoke EOI on the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_eoi_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_set_affinity_parent - Set affinity on the parent interrupt
 * @data:	Pointer to interrupt specific data
 * @dest:	The affinity mask to set
 * @force:	Flag to enforce setting (disable online checks)
 *
 * Conditional, as the underlying parent chip might not implement it.
 */
int irq_chip_set_affinity_parent(struct irq_data *data,
				 const struct cpumask *dest, bool force)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_set_type_parent - Set IRQ type on the parent interrupt
 * @data:	Pointer to interrupt specific data
 * @type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
 *
 * Conditional, as the underlying parent chip might not implement it.
 */
int irq_chip_set_type_parent(struct irq_data *data, unsigned int type)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_retrigger_hierarchy - Retrigger an interrupt in hardware
 * @data:	Pointer to interrupt specific data
 *
 * Iterate through the domain hierarchy of the interrupt and check
 * whether a hw retrigger function exists. If yes, invoke it.
 */
int irq_chip_retrigger_hierarchy(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_set_vcpu_affinity_parent - Set vcpu affinity on the parent interrupt
 * @data:	Pointer to interrupt specific data
 * @vcpu_info:	The vcpu affinity information
 */
int irq_chip_set_vcpu_affinity_parent(struct irq_data *data, void *vcpu_info)
{ … }
EXPORT_SYMBOL_GPL(…);
/**
 * irq_chip_set_wake_parent - Set/reset wake-up on the parent interrupt
 * @data:	Pointer to interrupt specific data
 * @on:		Whether to set or reset the wake-up capability of this irq
 *
 * Conditional, as the underlying parent chip might not implement it.
 */
int irq_chip_set_wake_parent(struct irq_data *data, unsigned int on)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_request_resources_parent - Request resources on the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
int irq_chip_request_resources_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * irq_chip_release_resources_parent - Release resources on the parent interrupt
 * @data:	Pointer to interrupt specific data
 */
void irq_chip_release_resources_parent(struct irq_data *data)
{ … }
EXPORT_SYMBOL_GPL(…);
#endif

/**
 * irq_chip_compose_msi_msg - Compose msi message for a irq chip
 * @data:	Pointer to interrupt specific data
 * @msg:	Pointer to the MSI message
 *
 * For hierarchical domains we find the first chip in the hierarchy
 * which implements the irq_compose_msi_msg callback. For non
 * hierarchical we use the top level chip.
 */
int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{ … }

static struct device *irq_get_pm_device(struct irq_data *data)
{ … }

/**
 * irq_chip_pm_get - Enable power for an IRQ chip
 * @data:	Pointer to interrupt specific data
 *
 * Enable the power to the IRQ chip referenced by the interrupt data
 * structure.
 */
int irq_chip_pm_get(struct irq_data *data)
{ … }

/**
 * irq_chip_pm_put - Disable power for an IRQ chip
 * @data:	Pointer to interrupt specific data
 *
 * Disable the power to the IRQ chip referenced by the interrupt data
 * structure, belongs. Note that power will only be disabled, once this
 * function has been called for all IRQs that have called irq_chip_pm_get().
 */
int irq_chip_pm_put(struct irq_data *data)
{ … }