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 */ |
88 | |