libnx  v4.2.2
counter.h
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1 /**
2  * @file counter.h
3  * @brief AArch64 system counter-timer.
4  * @author fincs
5  * @copyright libnx Authors
6  */
7 #pragma once
8 #include "../types.h"
9 
10 /**
11  * @brief Gets the current system tick.
12  * @return The current system tick.
13  */
14 static inline u64 armGetSystemTick(void) {
15  u64 ret;
16  __asm__ __volatile__ ("mrs %x[data], cntpct_el0" : [data] "=r" (ret));
17  return ret;
18 }
19 
20 /**
21  * @brief Gets the system counter-timer frequency
22  * @return The system counter-timer frequency, in Hz.
23  */
24 static inline u64 armGetSystemTickFreq(void) {
25  u64 ret;
26  __asm__ ("mrs %x[data], cntfrq_el0" : [data] "=r" (ret));
27  return ret;
28 }
29 
30 /**
31  * @brief Converts from nanoseconds to CPU ticks unit.
32  * @param ns Time in nanoseconds.
33  * @return Time in CPU ticks.
34  */
35 static inline u64 armNsToTicks(u64 ns) {
36  return (ns * 12) / 625;
37 }
38 
39 /**
40  * @brief Converts from CPU ticks unit to nanoseconds.
41  * @param tick Time in ticks.
42  * @return Time in nanoseconds.
43  */
44 static inline u64 armTicksToNs(u64 tick) {
45  return (tick * 625) / 12;
46 }
armGetSystemTickFreq
static u64 armGetSystemTickFreq(void)
Gets the system counter-timer frequency.
Definition: counter.h:24
armTicksToNs
static u64 armTicksToNs(u64 tick)
Converts from CPU ticks unit to nanoseconds.
Definition: counter.h:44
u64
uint64_t u64
64-bit unsigned integer.
Definition: types.h:22
armGetSystemTick
static u64 armGetSystemTick(void)
Gets the current system tick.
Definition: counter.h:14
armNsToTicks
static u64 armNsToTicks(u64 ns)
Converts from nanoseconds to CPU ticks unit.
Definition: counter.h:35