From 7b1f62076bba10786d2118006ae68ac120cd6c56 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 7 Nov 2012 17:58:54 -0700 Subject: time: convert arch_gettimeoffset to a pointer Currently, whenever CONFIG_ARCH_USES_GETTIMEOFFSET is enabled, each arch core provides a single implementation of arch_gettimeoffset(). In many cases, different sub-architectures, different machines, or different timer providers exist, and so the arch ends up implementing arch_gettimeoffset() as a call-through-pointer anyway. Examples are ARM, Cris, M68K, and it's arguable that the remaining architectures, M32R and Blackfin, should be doing this anyway. Modify arch_gettimeoffset so that it itself is a function pointer, which the arch initializes. This will allow later changes to move the initialization of this function into individual machine support or timer drivers. This is particularly useful for code in drivers/clocksource which should rely on an arch-independant mechanism to register their implementation of arch_gettimeoffset(). This patch also converts the Cris architecture to set arch_gettimeoffset directly to the final implementation in time_init(), because Cris already had separate time_init() functions per sub-architecture. M68K and ARM are converted to set arch_gettimeoffset to the final implementation in later patches, because they already have function pointers in place for this purpose. Cc: Russell King Cc: Mike Frysinger Cc: Mikael Starvik Cc: Hirokazu Takata Cc: Thomas Gleixner Acked-by: Geert Uytterhoeven Acked-by: Jesper Nilsson Acked-by: John Stultz Signed-off-by: Stephen Warren --- include/linux/time.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index 4d358e9d10f1..05e32a72103c 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -142,9 +142,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta); * finer then tick granular time. */ #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET -extern u32 arch_gettimeoffset(void); -#else -static inline u32 arch_gettimeoffset(void) { return 0; } +extern u32 (*arch_gettimeoffset)(void); #endif extern void do_gettimeofday(struct timeval *tv); -- cgit v1.2.2 From 1e817fb62cd185a2232ad4302579491805609489 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 19 Nov 2012 10:26:16 -0800 Subject: time: create __getnstimeofday for WARNless calls The pstore RAM backend can get called during resume, and must be defensive against a suspended time source. Expose getnstimeofday logic that returns an error instead of a WARN. This can be detected and the timestamp can be zeroed out. Reported-by: Doug Anderson Cc: John Stultz Cc: Anton Vorontsov Signed-off-by: Kees Cook Signed-off-by: John Stultz --- include/linux/time.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index 4d358e9d10f1..0015aea4c4a7 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -158,6 +158,7 @@ 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, -- cgit v1.2.2 From 31ade30692dc9680bfc95700d794818fa3f754ac Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Wed, 16 Jan 2013 00:09:47 +0800 Subject: timekeeping: Add persistent_clock_exist flag In current kernel, there are several places which need to check whether there is a persistent clock for the platform. Current check is done by calling the read_persistent_clock() and validating its return value. So one optimization is to do the check only once in timekeeping_init(), and use a flag persistent_clock_exist to record it. v2: Add a has_persistent_clock() helper function, as suggested by John. Cc: Thomas Gleixner Cc: John Stultz Signed-off-by: Feng Tang Signed-off-by: John Stultz --- include/linux/time.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index 0015aea4c4a7..dfbc4e82e8ba 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -115,6 +115,12 @@ static inline bool timespec_valid_strict(const struct timespec *ts) return true; } +extern bool persistent_clock_exist; +static inline bool has_persistent_clock(void) +{ + return persistent_clock_exist; +} + extern void read_persistent_clock(struct timespec *ts); extern void read_boot_clock(struct timespec *ts); extern int update_persistent_clock(struct timespec now); -- cgit v1.2.2 From 05ad717c77b1b8e98a1dd768c3700036d634629e Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Wed, 16 Jan 2013 00:09:49 +0800 Subject: timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK option Make the persistent clock check a kernel config option, so that some platform can explicitely select it, also make CONFIG_RTC_HCTOSYS and RTC_SYSTOHC depend on its non-existence, which could prevent the persistent clock and RTC code from doing similar thing twice during system's init/suspend/resume phases. If the CONFIG_HAS_PERSISTENT_CLOCK=n, then no change happens for kernel which still does the persistent clock check in timekeeping_init(). Cc: Thomas Gleixner Suggested-by: John Stultz Signed-off-by: Feng Tang [jstultz: Added dependency for RTC_SYSTOHC as well] Signed-off-by: John Stultz --- include/linux/time.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index dfbc4e82e8ba..369b6e3b87d8 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -116,10 +116,15 @@ static inline bool timespec_valid_strict(const struct timespec *ts) } extern bool persistent_clock_exist; + +#ifdef CONFIG_HAS_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); -- cgit v1.2.2 From 6f16eebe1ff82176339a0439c98ebec9768b0ee2 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 25 Jan 2013 17:08:12 -0800 Subject: timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCK Jason pointed out the HAS_PERSISTENT_CLOCK name isn't quite accurate for the config, as some systems may have the persistent_clock in some cases, but not always. So change the config name to the more clear ALWAYS_USE_PERSISTENT_CLOCK. Signed-off-by: John Stultz --- include/linux/time.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index 369b6e3b87d8..476e1d7b2c37 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -117,7 +117,7 @@ static inline bool timespec_valid_strict(const struct timespec *ts) extern bool persistent_clock_exist; -#ifdef CONFIG_HAS_PERSISTENT_CLOCK +#ifdef ALWAYS_USE_PERSISTENT_CLOCK #define has_persistent_clock() true #else static inline bool has_persistent_clock(void) -- cgit v1.2.2 From 84e345e4e209cbe796c88fa2ad1732d7121ec100 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Fri, 8 Feb 2013 17:59:53 -0500 Subject: time, Fix setting of hardware clock in NTP code At init time, if the system time is "warped" forward in warp_clock() it will differ from the hardware clock by sys_tz.tz_minuteswest. This time difference is not taken into account when ntp updates the hardware clock, and this causes the system time to jump forward by this offset every reboot. The kernel must take this offset into account when writing the system time to the hardware clock in the ntp code. This patch adds persistent_clock_is_local which indicates that an offset has been applied in warp_clock() and accounts for the "warp" before writing the hardware clock. x86 does not have this problem as rtc writes are software limited to a +/-15 minute window relative to the current rtc time. Other arches, such as powerpc, however do a full synchronization of the system time to the rtc and will see this problem. [v2]: generated against tip/timers/core Signed-off-by: Prarit Bhargava Cc: John Stultz Cc: Thomas Gleixner Signed-off-by: John Stultz --- include/linux/time.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/time.h') diff --git a/include/linux/time.h b/include/linux/time.h index 476e1d7b2c37..a3ab6a814a9c 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -128,6 +128,7 @@ static inline bool has_persistent_clock(void) extern void read_persistent_clock(struct timespec *ts); extern void read_boot_clock(struct timespec *ts); +extern int persistent_clock_is_local; extern int update_persistent_clock(struct timespec now); void timekeeping_init(void); extern int timekeeping_suspended; -- cgit v1.2.2