cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dm-io-tracker.h (1530B)

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