From 197c12b1a19f5fe05adf8359ff9013f43ba027da Mon Sep 17 00:00:00 2001 From: Yang Zhang Date: Wed, 7 Mar 2012 07:36:15 +0000 Subject: [PATCH] RTC: Add UIP(update in progress) check logic The UIP(update in progress) is set when RTC is in updating. And the update cycle begins 244us later after UIP is set. Signed-off-by: Yang Zhang Committed-by: Keir Fraser --- xen/arch/x86/hvm/rtc.c | 20 ++++++++++++++++++++ xen/arch/x86/time.c | 7 +++++++ xen/include/xen/time.h | 1 + 3 files changed, 28 insertions(+) diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c index b5fffc1634..00e5c83125 100644 --- a/xen/arch/x86/hvm/rtc.c +++ b/xen/arch/x86/hvm/rtc.c @@ -28,6 +28,8 @@ #include #include +#define USEC_PER_SEC 1000000UL + #define domain_vrtc(x) (&(x)->arch.hvm_domain.pl_time.vrtc) #define vcpu_vrtc(x) (domain_vrtc((x)->domain)) #define vrtc_domain(x) (container_of((x), struct domain, \ @@ -239,6 +241,22 @@ static void rtc_copy_date(RTCState *s) s->hw.cmos_data[RTC_YEAR] = to_bcd(s, tm->tm_year % 100); } +static int update_in_progress(RTCState *s) +{ + uint64_t guest_usec; + struct domain *d = vrtc_domain(s); + + if (s->hw.cmos_data[RTC_REG_B] & RTC_SET) + return 0; + + guest_usec = get_localtime_us(d); + /* UIP bit will be set at last 244us of every second. */ + if ((guest_usec % USEC_PER_SEC) >= (USEC_PER_SEC - 244)) + return 1; + + return 0; +} + static uint32_t rtc_ioport_read(RTCState *s, uint32_t addr) { int ret; @@ -268,6 +286,8 @@ static uint32_t rtc_ioport_read(RTCState *s, uint32_t addr) break; case RTC_REG_A: ret = s->hw.cmos_data[s->hw.cmos_index]; + if (update_in_progress(s)) + ret |= RTC_UIP; break; case RTC_REG_C: ret = s->hw.cmos_data[s->hw.cmos_index]; diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index f1a2a2599a..91682bd0f1 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -1601,6 +1601,13 @@ unsigned long get_localtime(struct domain *d) + d->time_offset_seconds; } +/* Return microsecs after 00:00:00 localtime, 1 January, 1970. */ +uint64_t get_localtime_us(struct domain *d) +{ + return ((wc_sec + d->time_offset_seconds) * 1000000000ULL + + wc_nsec + NOW()) / 1000UL; +} + unsigned long get_sec(void) { return wc_sec + (wc_nsec + NOW()) / 1000000000ULL; diff --git a/xen/include/xen/time.h b/xen/include/xen/time.h index 31c9ce5938..0b2eaade3a 100644 --- a/xen/include/xen/time.h +++ b/xen/include/xen/time.h @@ -34,6 +34,7 @@ typedef s64 s_time_t; s_time_t get_s_time(void); unsigned long get_localtime(struct domain *d); +uint64_t get_localtime_us(struct domain *d); struct tm { int tm_sec; /* seconds */ -- 2.30.2