| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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 */ |