1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2021 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8 #ifndef DM_IO_TRACKER_H
9 #define DM_IO_TRACKER_H
10
11 #include <linux/jiffies.h>
12
13 struct dm_io_tracker {
14 spinlock_t lock;
15
16 /*
17 * Sectors of in-flight IO.
18 */
19 sector_t in_flight;
20
21 /*
22 * The time, in jiffies, when this device became idle
23 * (if it is indeed idle).
24 */
25 unsigned long idle_time;
26 unsigned long last_update_time;
27 };
28
dm_iot_init(struct dm_io_tracker * iot)29 static inline void dm_iot_init(struct dm_io_tracker *iot)
30 {
31 spin_lock_init(&iot->lock);
32 iot->in_flight = 0ul;
33 iot->idle_time = 0ul;
34 iot->last_update_time = jiffies;
35 }
36
dm_iot_idle_for(struct dm_io_tracker * iot,unsigned long j)37 static inline bool dm_iot_idle_for(struct dm_io_tracker *iot, unsigned long j)
38 {
39 bool r = false;
40
41 spin_lock_irq(&iot->lock);
42 if (!iot->in_flight)
43 r = time_after(jiffies, iot->idle_time + j);
44 spin_unlock_irq(&iot->lock);
45
46 return r;
47 }
48
dm_iot_idle_time(struct dm_io_tracker * iot)49 static inline unsigned long dm_iot_idle_time(struct dm_io_tracker *iot)
50 {
51 unsigned long r = 0;
52
53 spin_lock_irq(&iot->lock);
54 if (!iot->in_flight)
55 r = jiffies - iot->idle_time;
56 spin_unlock_irq(&iot->lock);
57
58 return r;
59 }
60
dm_iot_io_begin(struct dm_io_tracker * iot,sector_t len)61 static inline void dm_iot_io_begin(struct dm_io_tracker *iot, sector_t len)
62 {
63 spin_lock_irq(&iot->lock);
64 iot->in_flight += len;
65 spin_unlock_irq(&iot->lock);
66 }
67
dm_iot_io_end(struct dm_io_tracker * iot,sector_t len)68 static inline void dm_iot_io_end(struct dm_io_tracker *iot, sector_t len)
69 {
70 unsigned long flags;
71
72 if (!len)
73 return;
74
75 spin_lock_irqsave(&iot->lock, flags);
76 iot->in_flight -= len;
77 if (!iot->in_flight)
78 iot->idle_time = jiffies;
79 spin_unlock_irqrestore(&iot->lock, flags);
80 }
81
82 #endif
83