From 3565184ed0c1ea46bea5b792da5f72a83c43e49b Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Mon, 13 May 2013 18:56:06 +0100 Subject: x86: Increase precision of x86_platform.get/set_wallclock() 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 Signed-off-by: John Stultz --- arch/x86/include/asm/x86_init.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch/x86/include/asm/x86_init.h') diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index d8d99222b36a..828a1565ba57 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -142,6 +142,8 @@ struct x86_cpuinit_ops { void (*fixup_cpu_id)(struct cpuinfo_x86 *c, int node); }; +struct timespec; + /** * struct x86_platform_ops - platform specific runtime functions * @calibrate_tsc: calibrate TSC @@ -156,8 +158,8 @@ struct x86_cpuinit_ops { */ struct x86_platform_ops { unsigned long (*calibrate_tsc)(void); - unsigned long (*get_wallclock)(void); - int (*set_wallclock)(unsigned long nowtime); + void (*get_wallclock)(struct timespec *ts); + int (*set_wallclock)(const struct timespec *ts); void (*iommu_shutdown)(void); bool (*is_untracked_pat_range)(u64 start, u64 end); void (*nmi_init)(void); -- cgit