1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
4 */
5
6#ifndef __IRQ_KERN_H__
7#define __IRQ_KERN_H__
8
9#include <linux/interrupt.h>
10#include <linux/time-internal.h>
11#include <asm/ptrace.h>
12#include "irq_user.h"
13
14#define UM_IRQ_ALLOC	-1
15
16int um_request_irq(int irq, int fd, enum um_irq_type type,
17		   irq_handler_t handler, unsigned long irqflags,
18		   const char *devname, void *dev_id);
19
20#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
21/**
22 * um_request_irq_tt - request an IRQ with timetravel handler
23 *
24 * @irq: the IRQ number, or %UM_IRQ_ALLOC
25 * @fd: The file descriptor to request an IRQ for
26 * @type: read or write
27 * @handler: the (generic style) IRQ handler
28 * @irqflags: Linux IRQ flags
29 * @devname: name for this to show
30 * @dev_id: data pointer to pass to the IRQ handler
31 * @timetravel_handler: the timetravel interrupt handler, invoked with the IRQ
32 *	number, fd, dev_id and time-travel event pointer.
33 *
34 * Returns: The interrupt number assigned or a negative error.
35 *
36 * Note that the timetravel handler is invoked only if the time_travel_mode is
37 * %TT_MODE_EXTERNAL, and then it is invoked even while the system is suspended!
38 * This function must call time_travel_add_irq_event() for the event passed with
39 * an appropriate delay, before sending an ACK on the socket it was invoked for.
40 *
41 * If this was called while the system is suspended, then adding the event will
42 * cause the system to resume.
43 *
44 * Since this function will almost certainly have to handle the FD's condition,
45 * a read will consume the message, and after that it is up to the code using
46 * it to pass such a message to the @handler in whichever way it can.
47 *
48 * If time_travel_mode is not %TT_MODE_EXTERNAL the @timetravel_handler will
49 * not be invoked at all and the @handler must handle the FD becoming
50 * readable (or writable) instead. Use um_irq_timetravel_handler_used() to
51 * distinguish these cases.
52 *
53 * See virtio_uml.c for an example.
54 */
55int um_request_irq_tt(int irq, int fd, enum um_irq_type type,
56		      irq_handler_t handler, unsigned long irqflags,
57		      const char *devname, void *dev_id,
58		      void (*timetravel_handler)(int, int, void *,
59						 struct time_travel_event *));
60#else
61static inline
62int um_request_irq_tt(int irq, int fd, enum um_irq_type type,
63		      irq_handler_t handler, unsigned long irqflags,
64		      const char *devname, void *dev_id,
65		      void (*timetravel_handler)(int, int, void *,
66						 struct time_travel_event *))
67{
68	return um_request_irq(irq, fd, type, handler, irqflags,
69			      devname, dev_id);
70}
71#endif
72
73static inline bool um_irq_timetravel_handler_used(void)
74{
75	return time_travel_mode == TT_MODE_EXTERNAL;
76}
77
78void um_free_irq(int irq, void *dev_id);
79void free_irqs(void);
80#endif
81