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(&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 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 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 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