diff options
Diffstat (limited to 'arch/x86/include/asm/timer.h')
-rw-r--r-- | arch/x86/include/asm/timer.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h new file mode 100644 index 000000000..7365dd4ac --- /dev/null +++ b/arch/x86/include/asm/timer.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_TIMER_H +#define _ASM_X86_TIMER_H +#include <linux/pm.h> +#include <linux/percpu.h> +#include <linux/interrupt.h> +#include <linux/math64.h> + +#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 */ |