From bd624d75db21ea5402f9ecf4450b311794d80352 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 13 Feb 2015 08:54:56 +0800 Subject: clockevents: Introduce mode specific callbacks It is not possible for the clockevents core to know which modes (other than those with a corresponding feature flag) are supported by a particular implementation. And drivers are expected to handle transition to all modes elegantly, as ->set_mode() would be issued for them unconditionally. Now, adding support for a new mode complicates things a bit if we want to use the legacy ->set_mode() callback. We need to closely review all clockevents drivers to see if they would break on addition of a new mode. And after such reviews, it is found that we have to do non-trivial changes to most of the drivers [1]. Introduce mode-specific set_mode_*() callbacks, some of which the drivers may or may not implement. A missing callback would clearly convey the message that the corresponding mode isn't supported. A driver may still choose to keep supporting the legacy ->set_mode() callback, but ->set_mode() wouldn't be supporting any new modes beyond RESUME. If a driver wants to benefit from using a new mode, it would be required to migrate to the mode specific callbacks. The legacy ->set_mode() callback and the newly introduced mode-specific callbacks are mutually exclusive. Only one of them should be supported by the driver. Sanity check is done at the time of registration to distinguish between optional and required callbacks and to make error recovery and handling simpler. If the legacy ->set_mode() callback is provided, all mode specific ones would be ignored by the core but a warning is thrown if they are present. Call sites calling ->set_mode() directly are also updated to use __clockevents_set_mode() instead, as ->set_mode() may not be available anymore for few drivers. [1] https://lkml.org/lkml/2014/12/9/605 [2] https://lkml.org/lkml/2015/1/23/255 Suggested-by: Thomas Gleixner [2] Signed-off-by: Viresh Kumar Signed-off-by: Peter Zijlstra (Intel) Cc: Daniel Lezcano Cc: Frederic Weisbecker Cc: John Stultz Cc: Kevin Hilman Cc: Linus Torvalds Cc: Preeti U Murthy Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Link: http://lkml.kernel.org/r/792d59a40423f0acffc9bb0bec9de1341a06fa02.1423788565.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 2e4cb67f6e56..59af26b54d15 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -39,6 +39,8 @@ enum clock_event_mode { CLOCK_EVT_MODE_PERIODIC, CLOCK_EVT_MODE_ONESHOT, CLOCK_EVT_MODE_RESUME, + + /* Legacy ->set_mode() callback doesn't support below modes */ }; /* @@ -81,7 +83,11 @@ enum clock_event_mode { * @mode: operating mode assigned by the management code * @features: features * @retries: number of forced programming retries - * @set_mode: set mode function + * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. + * @set_mode_periodic: switch mode to periodic, if !set_mode + * @set_mode_oneshot: switch mode to oneshot, if !set_mode + * @set_mode_shutdown: switch mode to shutdown, if !set_mode + * @set_mode_resume: resume clkevt device, if !set_mode * @broadcast: function to broadcast events * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration @@ -108,9 +114,20 @@ struct clock_event_device { unsigned int features; unsigned long retries; - void (*broadcast)(const struct cpumask *mask); + /* + * Mode transition callback(s): Only one of the two groups should be + * defined: + * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. + * - set_mode_{shutdown|periodic|oneshot|resume}(). + */ void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); + int (*set_mode_periodic)(struct clock_event_device *); + int (*set_mode_oneshot)(struct clock_event_device *); + int (*set_mode_shutdown)(struct clock_event_device *); + int (*set_mode_resume)(struct clock_event_device *); + + void (*broadcast)(const struct cpumask *mask); void (*suspend)(struct clock_event_device *); void (*resume)(struct clock_event_device *); unsigned long min_delta_ticks; -- cgit v1.2.2 From fb82fe2fe8588745edd73aa3a6229facac5c1e15 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 11 Mar 2015 21:16:31 -0700 Subject: clocksource: Add 'max_cycles' to 'struct clocksource' In order to facilitate clocksource validation, add a 'max_cycles' field to the clocksource structure which will hold the maximum cycle value that can safely be multiplied without potentially causing an overflow. Signed-off-by: John Stultz Cc: Dave Jones Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Prarit Bhargava Cc: Richard Cochran Cc: Stephen Boyd Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1426133800-29329-4-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- include/linux/clocksource.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 9c78d15d33e4..16d048cadebb 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -56,6 +56,7 @@ struct module; * @shift: cycle to nanosecond divisor (power of two) * @max_idle_ns: max idle time permitted by the clocksource (nsecs) * @maxadj: maximum adjustment value to mult (~11%) + * @max_cycles: maximum safe cycle value which won't overflow on multiplication * @flags: flags describing special properties * @archdata: arch-specific data * @suspend: suspend function for the clocksource, if necessary @@ -76,7 +77,7 @@ struct clocksource { #ifdef CONFIG_ARCH_CLOCKSOURCE_DATA struct arch_clocksource_data archdata; #endif - + u64 max_cycles; const char *name; struct list_head list; int rating; @@ -189,7 +190,7 @@ extern struct clocksource * __init clocksource_default_clock(void); extern void clocksource_mark_unstable(struct clocksource *cs); extern u64 -clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask); +clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask, u64 *max_cycles); extern void clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec); -- cgit v1.2.2 From f8935983f110505daa38e8d36ee406807f83a069 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 11 Mar 2015 21:16:37 -0700 Subject: clocksource: Mostly kill clocksource_register() A long running project has been to clean up remaining uses of clocksource_register(), replacing it with the simpler clocksource_register_khz/hz() functions. However, there are a few cases where we need to self-define our mult/shift values, so switch the function to a more obviously internal __clocksource_register() name, and consolidate much of the internal logic so we don't have duplication. Signed-off-by: John Stultz Cc: Dave Jones Cc: David S. Miller Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Peter Zijlstra Cc: Prarit Bhargava Cc: Richard Cochran Cc: Stephen Boyd Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1426133800-29329-10-git-send-email-john.stultz@linaro.org [ Minor cleanups. ] Signed-off-by: Ingo Molnar --- include/linux/clocksource.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 16d048cadebb..bd98eaa4d005 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -179,7 +179,6 @@ static inline s64 clocksource_cyc2ns(cycle_t cycles, u32 mult, u32 shift) } -extern int clocksource_register(struct clocksource*); extern int clocksource_unregister(struct clocksource*); extern void clocksource_touch_watchdog(void); extern struct clocksource* clocksource_get_next(void); @@ -203,6 +202,15 @@ __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq); extern void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq); +/* + * Don't call this unless you are a default clocksource + * (AKA: jiffies) and absolutely have to. + */ +static inline int __clocksource_register(struct clocksource *cs) +{ + return __clocksource_register_scale(cs, 1, 0); +} + static inline int clocksource_register_hz(struct clocksource *cs, u32 hz) { return __clocksource_register_scale(cs, 1, hz); -- cgit v1.2.2 From fba9e07208c0f9d92d9f73761c99c8612039da44 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 11 Mar 2015 21:16:40 -0700 Subject: clocksource: Rename __clocksource_updatefreq_*() to __clocksource_update_freq_*() Ingo requested this function be renamed to improve readability, so I've renamed __clocksource_updatefreq_scale() as well as the __clocksource_updatefreq_hz/khz() functions to avoid squishedtogethernames. This touches some of the sh clocksources, which I've not tested. The arch/arm/plat-omap change is just a comment change for consistency. Signed-off-by: John Stultz Cc: Daniel Lezcano Cc: Dave Jones Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Prarit Bhargava Cc: Richard Cochran Cc: Stephen Boyd Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1426133800-29329-13-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- include/linux/clocksource.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index bd98eaa4d005..135509821c39 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -200,7 +200,7 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec); extern int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq); extern void -__clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq); +__clocksource_update_freq_scale(struct clocksource *cs, u32 scale, u32 freq); /* * Don't call this unless you are a default clocksource @@ -221,14 +221,14 @@ static inline int clocksource_register_khz(struct clocksource *cs, u32 khz) return __clocksource_register_scale(cs, 1000, khz); } -static inline void __clocksource_updatefreq_hz(struct clocksource *cs, u32 hz) +static inline void __clocksource_update_freq_hz(struct clocksource *cs, u32 hz) { - __clocksource_updatefreq_scale(cs, 1, hz); + __clocksource_update_freq_scale(cs, 1, hz); } -static inline void __clocksource_updatefreq_khz(struct clocksource *cs, u32 khz) +static inline void __clocksource_update_freq_khz(struct clocksource *cs, u32 khz) { - __clocksource_updatefreq_scale(cs, 1000, khz); + __clocksource_update_freq_scale(cs, 1000, khz); } -- cgit v1.2.2 From 876e78818def2983be55878b21f7152fbaebbd36 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Mar 2015 10:09:06 +0100 Subject: time: Rename timekeeper::tkr to timekeeper::tkr_mono In preparation of adding another tkr field, rename this one to tkr_mono. Also rename tk_read_base::base_mono to tk_read_base::base, since the structure is not specific to CLOCK_MONOTONIC and the mono name got added to the tk_read_base instance. Lots of trivial churn. Signed-off-by: Peter Zijlstra (Intel) Acked-by: John Stultz Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150319093400.344679419@infradead.org Signed-off-by: Ingo Molnar --- include/linux/timekeeper_internal.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index 05af9a334893..73df17f1535f 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -16,16 +16,16 @@ * @read: Read function of @clock * @mask: Bitmask for two's complement subtraction of non 64bit clocks * @cycle_last: @clock cycle value at last update - * @mult: NTP adjusted multiplier for scaled math conversion + * @mult: (NTP adjusted) multiplier for scaled math conversion * @shift: Shift value for scaled math conversion * @xtime_nsec: Shifted (fractional) nano seconds offset for readout - * @base_mono: ktime_t (nanoseconds) base time for readout + * @base: ktime_t (nanoseconds) base time for readout * * This struct has size 56 byte on 64 bit. Together with a seqcount it * occupies a single 64byte cache line. * * The struct is separate from struct timekeeper as it is also used - * for a fast NMI safe accessor to clock monotonic. + * for a fast NMI safe accessors. */ struct tk_read_base { struct clocksource *clock; @@ -35,12 +35,12 @@ struct tk_read_base { u32 mult; u32 shift; u64 xtime_nsec; - ktime_t base_mono; + ktime_t base; }; /** * struct timekeeper - Structure holding internal timekeeping values. - * @tkr: The readout base structure + * @tkr_mono: The readout base structure for CLOCK_MONOTONIC * @xtime_sec: Current CLOCK_REALTIME time in seconds * @ktime_sec: Current CLOCK_MONOTONIC time in seconds * @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset @@ -76,7 +76,7 @@ struct tk_read_base { * used instead. */ struct timekeeper { - struct tk_read_base tkr; + struct tk_read_base tkr_mono; u64 xtime_sec; unsigned long ktime_sec; struct timespec64 wall_to_monotonic; -- cgit v1.2.2 From 4a4ad80d32cea69ee93bd4589f24dc478804cd80 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Mar 2015 09:28:44 +0100 Subject: time: Add timerkeeper::tkr_raw Introduce tkr_raw and make use of it. base_raw -> tkr_raw.base clock->{mult,shift} -> tkr_raw.{mult.shift} Kill timekeeping_get_ns_raw() in favour of timekeeping_get_ns(&tkr_raw), this removes all mono_raw special casing. Duplicate the updates to tkr_mono.cycle_last into tkr_raw.cycle_last, both need the same value. Signed-off-by: Peter Zijlstra (Intel) Acked-by: John Stultz Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150319093400.422589590@infradead.org Signed-off-by: Ingo Molnar --- include/linux/timekeeper_internal.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index 73df17f1535f..fb86963859c7 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -41,6 +41,7 @@ struct tk_read_base { /** * struct timekeeper - Structure holding internal timekeeping values. * @tkr_mono: The readout base structure for CLOCK_MONOTONIC + * @tkr_raw: The readout base structure for CLOCK_MONOTONIC_RAW * @xtime_sec: Current CLOCK_REALTIME time in seconds * @ktime_sec: Current CLOCK_MONOTONIC time in seconds * @wall_to_monotonic: CLOCK_REALTIME to CLOCK_MONOTONIC offset @@ -48,7 +49,6 @@ struct tk_read_base { * @offs_boot: Offset clock monotonic -> clock boottime * @offs_tai: Offset clock monotonic -> clock tai * @tai_offset: The current UTC to TAI offset in seconds - * @base_raw: Monotonic raw base time in ktime_t format * @raw_time: Monotonic raw base time in timespec64 format * @cycle_interval: Number of clock cycles in one NTP interval * @xtime_interval: Number of clock shifted nano seconds in one NTP @@ -77,6 +77,7 @@ struct tk_read_base { */ struct timekeeper { struct tk_read_base tkr_mono; + struct tk_read_base tkr_raw; u64 xtime_sec; unsigned long ktime_sec; struct timespec64 wall_to_monotonic; @@ -84,7 +85,6 @@ struct timekeeper { ktime_t offs_boot; ktime_t offs_tai; s32 tai_offset; - ktime_t base_raw; struct timespec64 raw_time; /* The following members are for timekeeping internal use */ -- cgit v1.2.2 From f09cb9a1808e35ad7502ea39b6bfb443c7fa0f19 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Mar 2015 09:39:08 +0100 Subject: time: Introduce tk_fast_raw Add the NMI safe CLOCK_MONOTONIC_RAW accessor.. Signed-off-by: Peter Zijlstra (Intel) Acked-by: John Stultz Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150319093400.562746929@infradead.org Signed-off-by: Ingo Molnar --- include/linux/timekeeping.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 3eaae4754275..f36b1edf3f73 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -220,6 +220,7 @@ static inline u64 ktime_get_raw_ns(void) } extern u64 ktime_get_mono_fast_ns(void); +extern u64 ktime_get_raw_fast_ns(void); /* * Timespec interfaces utilizing the ktime based ones -- cgit v1.2.2 From fe5fba05b46c791c95a9f34228ac495f81f72fc0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 17 Mar 2015 12:39:10 +0100 Subject: time: Add ktime_get_tai_ns() Because it was the only clock for which we didn't have a _ns() accessor yet. Signed-off-by: Peter Zijlstra (Intel) Cc: John Stultz Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- include/linux/timekeeping.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include') diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index f36b1edf3f73..5047b83483d6 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -214,6 +214,11 @@ static inline u64 ktime_get_boot_ns(void) return ktime_to_ns(ktime_get_boottime()); } +static inline u64 ktime_get_tai_ns(void) +{ + return ktime_to_ns(ktime_get_clocktai()); +} + static inline u64 ktime_get_raw_ns(void) { return ktime_to_ns(ktime_get_raw()); -- cgit v1.2.2