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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* IRQ offload/bypass manager
*
* Copyright (C) 2015 Red Hat, Inc.
* Copyright (c) 2015 Linaro Ltd.
*/
#ifndef IRQBYPASS_H
#define IRQBYPASS_H
#include <linux/list.h>
struct irq_bypass_consumer;
/*
* Theory of operation
*
* The IRQ bypass manager is a simple set of lists and callbacks that allows
* IRQ producers (ex. physical interrupt sources) to be matched to IRQ
* consumers (ex. virtualization hardware that allows IRQ bypass or offload)
* via a shared token (ex. eventfd_ctx). Producers and consumers register
* independently. When a token match is found, the optional @stop callback
* will be called for each participant. The pair will then be connected via
* the @add_* callbacks, and finally the optional @start callback will allow
* any final coordination. When either participant is unregistered, the
* process is repeated using the @del_* callbacks in place of the @add_*
* callbacks. Match tokens must be unique per producer/consumer, 1:N pairings
* are not supported.
*/
/**
* struct irq_bypass_producer - IRQ bypass producer definition
* @node: IRQ bypass manager private list management
* @token: opaque token to match between producer and consumer (non-NULL)
* @irq: Linux IRQ number for the producer device
* @add_consumer: Connect the IRQ producer to an IRQ consumer (optional)
* @del_consumer: Disconnect the IRQ producer from an IRQ consumer (optional)
* @stop: Perform any quiesce operations necessary prior to add/del (optional)
* @start: Perform any startup operations necessary after add/del (optional)
*
* The IRQ bypass producer structure represents an interrupt source for
* participation in possible host bypass, for instance an interrupt vector
* for a physical device assigned to a VM.
*/
struct irq_bypass_producer {
struct list_head node;
void *token;
int irq;
int (*add_consumer)(struct irq_bypass_producer *,
struct irq_bypass_consumer *);
void (*del_consumer)(struct irq_bypass_producer *,
struct irq_bypass_consumer *);
void (*stop)(struct irq_bypass_producer *);
void (*start)(struct irq_bypass_producer *);
};
/**
* struct irq_bypass_consumer - IRQ bypass consumer definition
* @node: IRQ bypass manager private list management
* @token: opaque token to match between producer and consumer (non-NULL)
* @add_producer: Connect the IRQ consumer to an IRQ producer
* @del_producer: Disconnect the IRQ consumer from an IRQ producer
* @stop: Perform any quiesce operations necessary prior to add/del (optional)
* @start: Perform any startup operations necessary after add/del (optional)
*
* The IRQ bypass consumer structure represents an interrupt sink for
* participation in possible host bypass, for instance a hypervisor may
* support offloads to allow bypassing the host entirely or offload
* portions of the interrupt handling to the VM.
*/
struct irq_bypass_consumer {
struct list_head node;
void *token;
int (*add_producer)(struct irq_bypass_consumer *,
struct irq_bypass_producer *);
void (*del_producer)(struct irq_bypass_consumer *,
struct irq_bypass_producer *);
void (*stop)(struct irq_bypass_consumer *);
void (*start)(struct irq_bypass_consumer *);
};
int irq_bypass_register_producer(struct irq_bypass_producer *);
void irq_bypass_unregister_producer(struct irq_bypass_producer *);
int irq_bypass_register_consumer(struct irq_bypass_consumer *);
void irq_bypass_unregister_consumer(struct irq_bypass_consumer *);
#endif /* IRQBYPASS_H */
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