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/mc146818rtc.h | 4 ++-- arch/x86/include/asm/x86_init.h | 6 ++++-- 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'arch/x86/include/asm') diff --git a/arch/x86/include/asm/mc146818rtc.h b/arch/x86/include/asm/mc146818rtc.h index d354fb781c5..a55c7efcc4e 100644 --- a/arch/x86/include/asm/mc146818rtc.h +++ b/arch/x86/include/asm/mc146818rtc.h @@ -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 diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index d8d99222b36..828a1565ba5 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 v1.2.3-70-g09d2 From ce0b098981544d9f4e910ea48f3af3e726ca6d6b Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 28 May 2013 17:03:09 -0700 Subject: x86: Fix vrtc_get_time/set_mmss to use new timespec interface The patch "x86: Increase precision of x86_platform.get/set_wallclock" changed the x86 platform set_wallclock/get_wallclock interfaces to use nsec granular timespecs instead of a second granular interface. However, that patch missed converting the vrtc code, so this patch converts those functions to use timespecs. Many thanks to the kbuild test robot for finding this! Reported-by: kbuild test robot Signed-off-by: John Stultz --- arch/x86/include/asm/mrst-vrtc.h | 4 ++-- arch/x86/platform/mrst/vrtc.c | 11 ++++++----- 2 files changed, 8 insertions(+), 7 deletions(-) (limited to 'arch/x86/include/asm') diff --git a/arch/x86/include/asm/mrst-vrtc.h b/arch/x86/include/asm/mrst-vrtc.h index 73668abdbed..1e69a75412a 100644 --- a/arch/x86/include/asm/mrst-vrtc.h +++ b/arch/x86/include/asm/mrst-vrtc.h @@ -3,7 +3,7 @@ extern unsigned char vrtc_cmos_read(unsigned char reg); extern void vrtc_cmos_write(unsigned char val, unsigned char reg); -extern unsigned long vrtc_get_time(void); -extern int vrtc_set_mmss(unsigned long nowtime); +extern void vrtc_get_time(struct timespec *now); +extern int vrtc_set_mmss(const struct timespec *now); #endif diff --git a/arch/x86/platform/mrst/vrtc.c b/arch/x86/platform/mrst/vrtc.c index d62b0a3b5c1..5e355b134ba 100644 --- a/arch/x86/platform/mrst/vrtc.c +++ b/arch/x86/platform/mrst/vrtc.c @@ -56,7 +56,7 @@ void vrtc_cmos_write(unsigned char val, unsigned char reg) } EXPORT_SYMBOL_GPL(vrtc_cmos_write); -unsigned long vrtc_get_time(void) +void vrtc_get_time(struct timespec *now) { u8 sec, min, hour, mday, mon; unsigned long flags; @@ -82,17 +82,18 @@ unsigned long vrtc_get_time(void) printk(KERN_INFO "vRTC: sec: %d min: %d hour: %d day: %d " "mon: %d year: %d\n", sec, min, hour, mday, mon, year); - return mktime(year, mon, mday, hour, min, sec); + now->tv_sec = mktime(year, mon, mday, hour, min, sec); + now->tv_nsec = 0; } -int vrtc_set_mmss(unsigned long nowtime) +int vrtc_set_mmss(const struct timespec *now) { unsigned long flags; struct rtc_time tm; int year; int retval = 0; - rtc_time_to_tm(nowtime, &tm); + rtc_time_to_tm(now->tv_sec, &tm); if (!rtc_valid_tm(&tm) && tm.tm_year >= 72) { /* * tm.year is the number of years since 1900, and the @@ -110,7 +111,7 @@ int vrtc_set_mmss(unsigned long nowtime) } else { printk(KERN_ERR "%s: Invalid vRTC value: write of %lx to vRTC failed\n", - __FUNCTION__, nowtime); + __FUNCTION__, now->tv_sec); retval = -EINVAL; } return retval; -- cgit v1.2.3-70-g09d2