Merge branch 'fortglx/3.9/time' of git://git.linaro.org/people/jstultz/linux into timers/core

Trivial conflict in arch/x86/Kconfig

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

15 files changed, 141 insertions, 22 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 212c255b9347..f5bda78792d9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6598,7 +6598,7 @@ F:	drivers/dma/dw_dmac_regs.h
 F:      drivers/dma/dw_dmac.c
 
 TIMEKEEPING, NTP
-M:      John Stultz <johnstul@us.ibm.com>
+M:      John Stultz <john.stultz@linaro.org>
 M:      Thomas Gleixner <tglx@linutronix.de>
 T:      git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core
 S:      Supported
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 127361e093f4..aaba2e05a417 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -668,7 +668,7 @@ int update_persistent_clock(struct timespec now)
         struct rtc_time tm;
 
         if (!ppc_md.set_rtc_time)
-                return 0;
+                return -ENODEV;
 
         to_tm(now.tv_sec + 1 + timezone_offset, &tm);
         tm.tm_year -= 1900;
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 225543bf45a5..97b023f0cbe8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -106,6 +106,7 @@ config X86
         select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
         select GENERIC_TIME_VSYSCALL if X86_64
         select KTIME_SCALAR if X86_32
+        select ALWAYS_USE_PERSISTENT_CLOCK
         select GENERIC_STRNCPY_FROM_USER
         select GENERIC_STRNLEN_USER
         select HAVE_CONTEXT_TRACKING if X86_64
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 06ccb5073a3f..4b9ea101fe3b 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -623,7 +623,8 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
         ns_now = __cycles_2_ns(tsc_now);
 
         if (cpu_khz) {
-                *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
+                *scale = ((NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR) +
+                                cpu_khz / 2) / cpu_khz;
                 *offset = ns_now - mult_frac(tsc_now, *scale,
                                              (1UL << CYC2NS_SCALE_FACTOR));
         }
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 923a9da9c829..5e44eaabf457 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -20,14 +20,24 @@ if RTC_CLASS
 config RTC_HCTOSYS
         bool "Set system time from RTC on startup and resume"
         default y
+        depends on !ALWAYS_USE_PERSISTENT_CLOCK
         help
           If you say yes here, the system time (wall clock) will be set using
           the value read from a specified RTC device. This is useful to avoid
           unnecessary fsck runs at boot time, and to network better.
 
+config RTC_SYSTOHC
+        bool "Set the RTC time based on NTP synchronization"
+        default y
+        depends on !ALWAYS_USE_PERSISTENT_CLOCK
+        help
+          If you say yes here, the system time (wall clock) will be stored
+          in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11
+          minutes if userspace reports synchronized NTP status.
+
 config RTC_HCTOSYS_DEVICE
         string "RTC used to set the system time"
-        depends on RTC_HCTOSYS = y
+        depends on RTC_HCTOSYS = y || RTC_SYSTOHC = y
         default "rtc0"
         help
           The RTC device that will be used to (re)initialize the system
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 4418ef3f9ecc..ec2988b00a44 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -6,6 +6,7 @@ ccflags-$(CONFIG_RTC_DEBUG)	:= -DDEBUG
 
 obj-$(CONFIG_RTC_LIB)           += rtc-lib.o
 obj-$(CONFIG_RTC_HCTOSYS)       += hctosys.o
+obj-$(CONFIG_RTC_SYSTOHC)       += systohc.o
 obj-$(CONFIG_RTC_CLASS)         += rtc-core.o
 rtc-core-y                      := class.o interface.o
 
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 5143629dedbd..26388f182594 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -50,6 +50,10 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg)
         struct rtc_device       *rtc = to_rtc_device(dev);
         struct rtc_time         tm;
         struct timespec         delta, delta_delta;
+
+        if (has_persistent_clock())
+                return 0;
+
         if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
                 return 0;
 
@@ -88,6 +92,9 @@ static int rtc_resume(struct device *dev)
         struct timespec         new_system, new_rtc;
         struct timespec         sleep_time;
 
+        if (has_persistent_clock())
+                return 0;
+
         rtc_hctosys_ret = -ENODEV;
         if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
                 return 0;
diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c
new file mode 100644
index 000000000000..bf3e242ccc5c
--- /dev/null
+++ b/drivers/rtc/systohc.c
@@ -0,0 +1,44 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ */
+#include <linux/rtc.h>
+#include <linux/time.h>
+
+/**
+ * rtc_set_ntp_time - Save NTP synchronized time to the RTC
+ * @now: Current time of day
+ *
+ * Replacement for the NTP platform function update_persistent_clock
+ * that stores time for later retrieval by rtc_hctosys.
+ *
+ * Returns 0 on successful RTC update, -ENODEV if a RTC update is not
+ * possible at all, and various other -errno for specific temporary failure
+ * cases.
+ *
+ * If temporary failure is indicated the caller should try again 'soon'
+ */
+int rtc_set_ntp_time(struct timespec now)
+{
+        struct rtc_device *rtc;
+        struct rtc_time tm;
+        int err = -ENODEV;
+
+        if (now.tv_nsec < (NSEC_PER_SEC >> 1))
+                rtc_time_to_tm(now.tv_sec, &tm);
+        else
+                rtc_time_to_tm(now.tv_sec + 1, &tm);
+
+        rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
+        if (rtc) {
+                /* rtc_hctosys exclusively uses UTC, so we call set_time here,
+                 * not set_mmss. */
+                if (rtc->ops && (rtc->ops->set_time || rtc->ops->set_mmss))
+                        err = rtc_set_time(rtc, &tm);
+                rtc_class_close(rtc);
+        }
+
+        return err;
+}
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 7003e5266f25..288f068740f6 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -167,12 +167,16 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
 {
         char *hdr;
-        struct timeval timestamp;
+        struct timespec timestamp;
         size_t len;
 
-        do_gettimeofday(&timestamp);
+        /* Report zeroed timestamp if called before timekeeping has resumed. */
+        if (__getnstimeofday(&timestamp)) {
+                timestamp.tv_sec = 0;
+                timestamp.tv_nsec = 0;
+        }
         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
-                (long)timestamp.tv_sec, (long)timestamp.tv_usec);
+                (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000));
         WARN_ON_ONCE(!hdr);
         len = hdr ? strlen(hdr) : 0;
         persistent_ram_write(prz, hdr, len);
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 9531845c419f..11d05f9fe8b6 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -138,6 +138,7 @@ extern void rtc_device_unregister(struct rtc_device *rtc);
 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
+extern int rtc_set_ntp_time(struct timespec now);
 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
 extern int rtc_read_alarm(struct rtc_device *rtc,
                         struct rtc_wkalrm *alrm);
diff --git a/include/linux/time.h b/include/linux/time.h
index 4d358e9d10f1..476e1d7b2c37 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -115,6 +115,17 @@ static inline bool timespec_valid_strict(const struct timespec *ts)
         return true;
 }
 
+extern bool persistent_clock_exist;
+
+#ifdef ALWAYS_USE_PERSISTENT_CLOCK
+#define has_persistent_clock()  true
+#else
+static inline bool has_persistent_clock(void)
+{
+        return persistent_clock_exist;
+}
+#endif
+
 extern void read_persistent_clock(struct timespec *ts);
 extern void read_boot_clock(struct timespec *ts);
 extern int update_persistent_clock(struct timespec now);
@@ -158,6 +169,7 @@ extern int do_setitimer(int which, struct itimerval *value,
                         struct itimerval *ovalue);
 extern unsigned int alarm_setitimer(unsigned int seconds);
 extern int do_getitimer(int which, struct itimerval *value);
+extern int __getnstimeofday(struct timespec *tv);
 extern void getnstimeofday(struct timespec *tv);
 extern void getrawmonotonic(struct timespec *ts);
 extern void getnstime_raw_and_real(struct timespec *ts_raw,
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 69185ae6b701..10349d5f2ec3 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -997,7 +997,7 @@ SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
 
         err = kc->clock_adj(which_clock, &ktx);
 
-        if (!err && copy_to_user(utx, &ktx, sizeof(ktx)))
+        if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
                 return -EFAULT;
 
         return err;
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index b69692250af4..24510d84efd7 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -12,6 +12,11 @@ config CLOCKSOURCE_WATCHDOG
 config ARCH_CLOCKSOURCE_DATA
         bool
 
+# Platforms has a persistent clock
+config ALWAYS_USE_PERSISTENT_CLOCK
+        bool
+        default n
+
 # Timekeeping vsyscall support
 config GENERIC_TIME_VSYSCALL
         bool
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 24174b4d669b..313b161504b7 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -15,6 +15,7 @@
 #include <linux/time.h>
 #include <linux/mm.h>
 #include <linux/module.h>
+#include <linux/rtc.h>
 
 #include "tick-internal.h"
 
@@ -483,8 +484,7 @@ out:
         return leap;
 }
 
-#ifdef CONFIG_GENERIC_CMOS_UPDATE
-
+#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC)
 static void sync_cmos_clock(struct work_struct *work);
 
 static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
@@ -510,14 +510,22 @@ static void sync_cmos_clock(struct work_struct *work)
         }
 
         getnstimeofday(&now);
-        if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
+        if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) {
+                fail = -ENODEV;
+#ifdef CONFIG_GENERIC_CMOS_UPDATE
                 fail = update_persistent_clock(now);
+#endif
+#ifdef CONFIG_RTC_SYSTOHC
+                if (fail == -ENODEV)
+                        fail = rtc_set_ntp_time(now);
+#endif
+        }
 
         next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
         if (next.tv_nsec <= 0)
                 next.tv_nsec += NSEC_PER_SEC;
 
-        if (!fail)
+        if (!fail || fail == -ENODEV)
                 next.tv_sec = 659;
         else
                 next.tv_sec = 0;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cbc6acb0db3f..1e35515a875e 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -29,6 +29,9 @@ static struct timekeeper timekeeper;
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
 
+/* Flag for if there is a persistent clock on this platform */
+bool __read_mostly persistent_clock_exist = false;
+
 static inline void tk_normalize_xtime(struct timekeeper *tk)
 {
         while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
@@ -264,19 +267,18 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 }
 
 /**
- * getnstimeofday - Returns the time of day in a timespec
+ * __getnstimeofday - Returns the time of day in a timespec.
  * @ts:         pointer to the timespec to be set
  *
- * Returns the time of day in a timespec.
+ * Updates the time of day in the timespec.
+ * Returns 0 on success, or -ve when suspended (timespec will be undefined).
  */
-void getnstimeofday(struct timespec *ts)
+int __getnstimeofday(struct timespec *ts)
 {
         struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         s64 nsecs = 0;
 
-        WARN_ON(timekeeping_suspended);
-
         do {
                 seq = read_seqbegin(&tk->lock);
 
@@ -287,6 +289,26 @@ void getnstimeofday(struct timespec *ts)
 
         ts->tv_nsec = 0;
         timespec_add_ns(ts, nsecs);
+
+        /*
+         * Do not bail out early, in case there were callers still using
+         * the value, even in the face of the WARN_ON.
+         */
+        if (unlikely(timekeeping_suspended))
+                return -EAGAIN;
+        return 0;
+}
+EXPORT_SYMBOL(__getnstimeofday);
+
+/**
+ * getnstimeofday - Returns the time of day in a timespec.
+ * @ts:         pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec (WARN if suspended).
+ */
+void getnstimeofday(struct timespec *ts)
+{
+        WARN_ON(__getnstimeofday(ts));
 }
 EXPORT_SYMBOL(getnstimeofday);
 
@@ -640,12 +662,14 @@ void __init timekeeping_init(void)
         struct timespec now, boot, tmp;
 
         read_persistent_clock(&now);
+
         if (!timespec_valid_strict(&now)) {
                 pr_warn("WARNING: Persistent clock returned invalid value!\n"
                         "         Check your CMOS/BIOS settings.\n");
                 now.tv_sec = 0;
                 now.tv_nsec = 0;
-        }
+        } else if (now.tv_sec || now.tv_nsec)
+                persistent_clock_exist = true;
 
         read_boot_clock(&boot);
         if (!timespec_valid_strict(&boot)) {
@@ -718,11 +742,12 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 {
         struct timekeeper *tk = &timekeeper;
         unsigned long flags;
-        struct timespec ts;
 
-        /* Make sure we don't set the clock twice */
-        read_persistent_clock(&ts);
-        if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
+        /*
+         * Make sure we don't set the clock twice, as timekeeping_resume()
+         * already did it
+         */
+        if (has_persistent_clock())
                 return;
 
         write_seqlock_irqsave(&tk->lock, flags);