[PATCH 2/5] Added functions mapping TSC value to system time
From: Christopher Hall <hidden>
Date: 2015-07-28 00:47:21
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
* tsc_to_rawmono64 * tsc_to_realtime64 * tsc_to_mono64 These function build on the counter_to_* time translation function specifically for TSC based system clock Signed-off-by: Christopher Hall <redacted> --- arch/x86/include/asm/tsc.h | 5 +++++ arch/x86/kernel/tsc.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index 94605c0..3fdf8b1 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h@@ -5,6 +5,7 @@ #define _ASM_X86_TSC_H #include <asm/processor.h> +#include <linux/time64.h> #define NS_SCALE 10 /* 2^10, carefully chosen */ #define US_SCALE 32 /* 2^32, arbitralrily chosen */
@@ -52,6 +53,10 @@ extern int check_tsc_unstable(void); extern int check_tsc_disabled(void); extern unsigned long native_calibrate_tsc(void); +extern int tsc_to_rawmono64(struct timespec64 *rawmono, cycle_t counterval); +extern int tsc_to_realtime64(struct timespec64 *realtime, cycle_t counterval); +extern int tsc_to_mono64(struct timespec64 *mono, cycle_t counterval); + extern int tsc_clocksource_reliable; /*
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 7437b41..a192271 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c@@ -979,6 +979,24 @@ static cycle_t read_tsc(struct clocksource *cs) return (cycle_t)get_cycles(); } +int tsc_to_rawmono64(struct timespec64 *rawmono, cycle_t counterval) +{ + return counter_to_rawmono64(rawmono, counterval, &clocksource_tsc); +} +EXPORT_SYMBOL(tsc_to_rawmono64); + +int tsc_to_realtime64(struct timespec64 *realtime, cycle_t counterval) +{ + return counter_to_realtime64(realtime, counterval, &clocksource_tsc); +} +EXPORT_SYMBOL(tsc_to_realtime64); + +int tsc_to_mono64(struct timespec64 *mono, cycle_t counterval) +{ + return counter_to_mono64(mono, counterval, &clocksource_tsc); +} +EXPORT_SYMBOL(tsc_to_mono64); + /* * .mask MUST be CLOCKSOURCE_MASK(64). See comment above read_tsc() */
--
1.9.1