| 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 | |
| 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 | |
| 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(lock: &iot->lock); |
| 42 | if (!iot->in_flight) |
| 43 | r = time_after(jiffies, iot->idle_time + j); |
| 44 | spin_unlock_irq(lock: &iot->lock); |
| 45 | |
| 46 | return r; |
| 47 | } |
| 48 | |
| 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(lock: &iot->lock); |
| 54 | if (!iot->in_flight) |
| 55 | r = jiffies - iot->idle_time; |
| 56 | spin_unlock_irq(lock: &iot->lock); |
| 57 | |
| 58 | return r; |
| 59 | } |
| 60 | |
| 61 | static inline void dm_iot_io_begin(struct dm_io_tracker *iot, sector_t len) |
| 62 | { |
| 63 | spin_lock_irq(lock: &iot->lock); |
| 64 | iot->in_flight += len; |
| 65 | spin_unlock_irq(lock: &iot->lock); |
| 66 | } |
| 67 | |
| 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(lock: &iot->lock, flags); |
| 80 | } |
| 81 | |
| 82 | #endif |
| 83 |