/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_TIMER_H #define _ASM_X86_TIMER_H #include #include #include #include #define TICK_SIZE (tick_nsec / 1000) unsigned long long native_sched_clock(void); extern void recalibrate_cpu_khz(void); extern int no_timer_check; extern bool using_native_sched_clock(void); /* * We use the full linear equation: f(x) = a + b*x, in order to allow * a continuous function in the face of dynamic freq changes. * * Continuity means that when our frequency changes our slope (b); we want to * ensure that: f(t) == f'(t), which gives: a + b*t == a' + b'*t. * * Without an offset (a) the above would not be possible. * * See the comment near cycles_2_ns() for details on how we compute (b). */ struct cyc2ns_data { u32 cyc2ns_mul; u32 cyc2ns_shift; u64 cyc2ns_offset; }; /* 16 bytes */ extern void cyc2ns_read_begin(struct cyc2ns_data *); extern void cyc2ns_read_end(void); #endif /* _ASM_X86_TIMER_H */