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-rw-r--r--MAINTAINERS2
-rw-r--r--arch/powerpc/kernel/time.c2
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/kernel/tsc.c3
-rw-r--r--drivers/rtc/Kconfig12
-rw-r--r--drivers/rtc/Makefile1
-rw-r--r--drivers/rtc/class.c7
-rw-r--r--drivers/rtc/systohc.c44
-rw-r--r--fs/pstore/ram.c10
-rw-r--r--include/linux/rtc.h1
-rw-r--r--include/linux/time.h12
-rw-r--r--kernel/posix-timers.c2
-rw-r--r--kernel/time/Kconfig5
-rw-r--r--kernel/time/ntp.c16
-rw-r--r--kernel/time/timekeeping.c45
15 files changed, 141 insertions, 22 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 212c255b934..f5bda78792d 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 127361e093f..aaba2e05a41 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 225543bf45a..97b023f0cbe 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 06ccb5073a3..4b9ea101fe3 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 923a9da9c82..5e44eaabf45 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 4418ef3f9ec..ec2988b00a4 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 5143629dedb..26388f18259 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 00000000000..bf3e242ccc5
--- /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 7003e5266f2..288f068740f 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 9531845c419..11d05f9fe8b 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 4d358e9d10f..476e1d7b2c3 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 69185ae6b70..10349d5f2ec 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 b69692250af..24510d84efd 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 24174b4d669..313b161504b 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 cbc6acb0db3..1e35515a875 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);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-01 18:43:22 +0000