1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __I8254_H
3#define __I8254_H
4
5#include <linux/kthread.h>
6
7#include <kvm/iodev.h>
8
9struct kvm_kpit_channel_state {
10 u32 count; /* can be 65536 */
11 u16 latched_count;
12 u8 count_latched;
13 u8 status_latched;
14 u8 status;
15 u8 read_state;
16 u8 write_state;
17 u8 write_latch;
18 u8 rw_mode;
19 u8 mode;
20 u8 bcd; /* not supported */
21 u8 gate; /* timer start */
22 ktime_t count_load_time;
23};
24
25struct kvm_kpit_state {
26 /* All members before "struct mutex lock" are protected by the lock. */
27 struct kvm_kpit_channel_state channels[3];
28 u32 flags;
29 bool is_periodic;
30 s64 period; /* unit: ns */
31 struct hrtimer timer;
32
33 struct mutex lock;
34 atomic_t reinject;
35 atomic_t pending; /* accumulated triggered timers */
36 atomic_t irq_ack;
37 struct kvm_irq_ack_notifier irq_ack_notifier;
38};
39
40struct kvm_pit {
41 struct kvm_io_device dev;
42 struct kvm_io_device speaker_dev;
43 struct kvm *kvm;
44 struct kvm_kpit_state pit_state;
45 int irq_source_id;
46 struct kvm_irq_mask_notifier mask_notifier;
47 struct kthread_worker *worker;
48 struct kthread_work expired;
49};
50
51#define KVM_PIT_BASE_ADDRESS 0x40
52#define KVM_SPEAKER_BASE_ADDRESS 0x61
53#define KVM_PIT_MEM_LENGTH 4
54#define KVM_PIT_FREQ 1193181
55#define KVM_MAX_PIT_INTR_INTERVAL HZ / 100
56#define KVM_PIT_CHANNEL_MASK 0x3
57
58struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags);
59void kvm_free_pit(struct kvm *kvm);
60
61void kvm_pit_load_count(struct kvm_pit *pit, int channel, u32 val,
62 int hpet_legacy_start);
63void kvm_pit_set_reinject(struct kvm_pit *pit, bool reinject);
64
65#endif
66

source code of linux/arch/x86/kvm/i8254.h