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
  11 unsigned long long native_sched_clock(void);
  12 extern void recalibrate_cpu_khz(void);
  13
  14 extern int no_timer_check;
  15
  16 extern 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  */
  29 struct cyc2ns_data {
  30         u32 cyc2ns_mul;
  31         u32 cyc2ns_shift;
  32         u64 cyc2ns_offset;
  33 }; /* 16 bytes */
  34
  35 extern void cyc2ns_read_begin(struct cyc2ns_data *);
  36 extern void cyc2ns_read_end(void);
  37
  38 #endif /* _ASM_X86_TIMER_H */