LXR linux/arch/x86/include/asm/timer.h

   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 */
  39