1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * IRQ offload/bypass manager
4 *
5 * Copyright (C) 2015 Red Hat, Inc.
6 * Copyright (c) 2015 Linaro Ltd.
7 */
8 #ifndef IRQBYPASS_H
9 #define IRQBYPASS_H
10
11 #include <linux/list.h>
12
13 struct irq_bypass_consumer;
14
15 /*
16 * Theory of operation
17 *
18 * The IRQ bypass manager is a simple set of lists and callbacks that allows
19 * IRQ producers (ex. physical interrupt sources) to be matched to IRQ
20 * consumers (ex. virtualization hardware that allows IRQ bypass or offload)
21 * via a shared token (ex. eventfd_ctx). Producers and consumers register
22 * independently. When a token match is found, the optional @stop callback
23 * will be called for each participant. The pair will then be connected via
24 * the @add_* callbacks, and finally the optional @start callback will allow
25 * any final coordination. When either participant is unregistered, the
26 * process is repeated using the @del_* callbacks in place of the @add_*
27 * callbacks. Match tokens must be unique per producer/consumer, 1:N pairings
28 * are not supported.
29 */
30
31 /**
32 * struct irq_bypass_producer - IRQ bypass producer definition
33 * @node: IRQ bypass manager private list management
34 * @token: opaque token to match between producer and consumer (non-NULL)
35 * @irq: Linux IRQ number for the producer device
36 * @add_consumer: Connect the IRQ producer to an IRQ consumer (optional)
37 * @del_consumer: Disconnect the IRQ producer from an IRQ consumer (optional)
38 * @stop: Perform any quiesce operations necessary prior to add/del (optional)
39 * @start: Perform any startup operations necessary after add/del (optional)
40 *
41 * The IRQ bypass producer structure represents an interrupt source for
42 * participation in possible host bypass, for instance an interrupt vector
43 * for a physical device assigned to a VM.
44 */
45 struct irq_bypass_producer {
46 struct list_head node;
47 void *token;
48 int irq;
49 int (*add_consumer)(struct irq_bypass_producer *,
50 struct irq_bypass_consumer *);
51 void (*del_consumer)(struct irq_bypass_producer *,
52 struct irq_bypass_consumer *);
53 void (*stop)(struct irq_bypass_producer *);
54 void (*start)(struct irq_bypass_producer *);
55 };
56
57 /**
58 * struct irq_bypass_consumer - IRQ bypass consumer definition
59 * @node: IRQ bypass manager private list management
60 * @token: opaque token to match between producer and consumer (non-NULL)
61 * @add_producer: Connect the IRQ consumer to an IRQ producer
62 * @del_producer: Disconnect the IRQ consumer from an IRQ producer
63 * @stop: Perform any quiesce operations necessary prior to add/del (optional)
64 * @start: Perform any startup operations necessary after add/del (optional)
65 *
66 * The IRQ bypass consumer structure represents an interrupt sink for
67 * participation in possible host bypass, for instance a hypervisor may
68 * support offloads to allow bypassing the host entirely or offload
69 * portions of the interrupt handling to the VM.
70 */
71 struct irq_bypass_consumer {
72 struct list_head node;
73 void *token;
74 int (*add_producer)(struct irq_bypass_consumer *,
75 struct irq_bypass_producer *);
76 void (*del_producer)(struct irq_bypass_consumer *,
77 struct irq_bypass_producer *);
78 void (*stop)(struct irq_bypass_consumer *);
79 void (*start)(struct irq_bypass_consumer *);
80 };
81
82 int irq_bypass_register_producer(struct irq_bypass_producer *);
83 void irq_bypass_unregister_producer(struct irq_bypass_producer *);
84 int irq_bypass_register_consumer(struct irq_bypass_consumer *);
85 void irq_bypass_unregister_consumer(struct irq_bypass_consumer *);
86
87 #endif /* IRQBYPASS_H */