1 #ifndef _ASM_X86_TIMER_H 2 #define _ASM_X86_TIMER_H 3 #include <linux/pm.h> 4 #include <linux/percpu.h> 5 #include <linux/interrupt.h> 6 #include <linux/math64.h> 7 8 #define TICK_SIZE (tick_nsec / 1000) 9 10 unsigned long long native_sched_clock(void); 11 extern int recalibrate_cpu_khz(void); 12 13 extern int no_timer_check; 14 15 extern bool using_native_sched_clock(void); 16 17 /* 18 * We use the full linear equation: f(x) = a + b*x, in order to allow 19 * a continuous function in the face of dynamic freq changes. 20 * 21 * Continuity means that when our frequency changes our slope (b); we want to 22 * ensure that: f(t) == f'(t), which gives: a + b*t == a' + b'*t. 23 * 24 * Without an offset (a) the above would not be possible. 25 * 26 * See the comment near cycles_2_ns() for details on how we compute (b). 27 */ 28 struct cyc2ns_data { 29 u32 cyc2ns_mul; 30 u32 cyc2ns_shift; 31 u64 cyc2ns_offset; 32 u32 __count; 33 /* u32 hole */ 34 }; /* 24 bytes -- do not grow */ 35 36 extern struct cyc2ns_data *cyc2ns_read_begin(void); 37 extern void cyc2ns_read_end(struct cyc2ns_data *); 38 39 #endif /* _ASM_X86_TIMER_H */ 40