xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86: Increase precision of x86_platform.get/set_wallclock()

Browse Source 
All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.

read_persistent_wallclock() and update_persistent_wallclock() allow
for nanosecond precision but their implementation on x86 with
x86_platform.get/set_wallclock() only allows for one second precision.
This means guests may see a wallclock time that is off by up to 1
second.

Make set_wallclock() and get_wallclock() take a struct timespec
parameter (which allows for nanosecond precision) so KVM and Xen
guests may start with a more accurate wallclock time and a Xen dom0
can maintain a more accurate wallclock for guests.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
David Vrabel
2013-05-13 18:56:06 +01:00
committed by John Stultz
parent 0a0a7e66fa
commit 3565184ed0
8 changed files with 32 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/include/asm/mc146818rtc.h
View File

@@ -95,8 +95,8 @@ static inline unsigned char current_lock_cmos_reg(void)
unsigned char rtc_cmos_read(unsigned char addr);
void rtc_cmos_write(unsigned char val, unsigned char addr);
extern int mach_set_rtc_mmss(unsigned long nowtime);
extern unsigned long mach_get_cmos_time(void);
extern int mach_set_rtc_mmss(const struct timespec *now);
extern void mach_get_cmos_time(struct timespec *now);
#define RTC_IRQ 8