timer.h (1027B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_X86_TIMER_H 3#define _ASM_X86_TIMER_H 4#include <linux/pm.h> 5#include <linux/percpu.h> 6#include <linux/interrupt.h> 7#include <linux/math64.h> 8 9#define TICK_SIZE (tick_nsec / 1000) 10 11unsigned long long native_sched_clock(void); 12extern void recalibrate_cpu_khz(void); 13 14extern int no_timer_check; 15 16extern bool using_native_sched_clock(void); 17 18/* 19 * We use the full linear equation: f(x) = a + b*x, in order to allow 20 * a continuous function in the face of dynamic freq changes. 21 * 22 * Continuity means that when our frequency changes our slope (b); we want to 23 * ensure that: f(t) == f'(t), which gives: a + b*t == a' + b'*t. 24 * 25 * Without an offset (a) the above would not be possible. 26 * 27 * See the comment near cycles_2_ns() for details on how we compute (b). 28 */ 29struct cyc2ns_data { 30 u32 cyc2ns_mul; 31 u32 cyc2ns_shift; 32 u64 cyc2ns_offset; 33}; /* 16 bytes */ 34 35extern void cyc2ns_read_begin(struct cyc2ns_data *); 36extern void cyc2ns_read_end(void); 37 38#endif /* _ASM_X86_TIMER_H */