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/linux/clockchips.h') 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 v1.2.3 From 554ef3876c6acdff1331feab10275e9e9e0adb84 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 27 Feb 2015 17:21:32 +0530 Subject: clockevents: Handle tick device's resume separately Upcoming patch will redefine possible states of a clockevent device. The RESUME mode is a special case only for tick's clockevent devices. In future it can be replaced by ->resume() callback already available for clockevent devices. Lets handle it separately so that clockevents_set_mode() only handles states valid across all devices. This also renames set_mode_resume() to tick_resume() to make it more explicit. Signed-off-by: Viresh Kumar Acked-by: Peter Zijlstra Cc: Daniel Lezcano Cc: Frederic Weisbecker Cc: Kevin Hilman Cc: Peter Zijlstra Cc: Preeti U Murthy Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/c1b0112410870f49e7bf06958e1483eac6c15e20.1425037853.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 59af26b54d15..a41749543d48 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -87,7 +87,7 @@ enum clock_event_mode { * @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 + * @tick_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 @@ -125,7 +125,7 @@ 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 *); + int (*tick_resume)(struct clock_event_device *); void (*broadcast)(const struct cpumask *mask); void (*suspend)(struct clock_event_device *); -- cgit v1.2.3 From 77e32c89a7117614ab3d66d20c1088de721abfaa Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 27 Feb 2015 17:21:33 +0530 Subject: clockevents: Manage device's state separately for the core 'enum clock_event_mode' is used for two purposes today: - to pass mode to the driver of clockevent device::set_mode(). - for managing state of the device for clockevents core. For supporting new modes/states we have moved away from the legacy set_mode() callback to new per-mode/state callbacks. New modes/states shouldn't be exposed to the legacy (now OBSOLOTE) callbacks and so we shouldn't add new states to 'enum clock_event_mode'. Lets have separate enums for the two use cases mentioned above. Keep using the earlier enum for legacy set_mode() callback and mark it OBSOLETE. And add another enum to clearly specify the possible states of a clockevent device. This also renames the newly added per-mode callbacks to reflect state changes. We haven't got rid of 'mode' member of 'struct clock_event_device' as it is used by some of the clockevent drivers and it would automatically die down once we migrate those drivers to the new interface. It ('mode') is only updated now for the drivers using the legacy interface. Suggested-by: Peter Zijlstra Suggested-by: Ingo Molnar Signed-off-by: Viresh Kumar Acked-by: Peter Zijlstra Cc: Daniel Lezcano Cc: Frederic Weisbecker Cc: Kevin Hilman Cc: Preeti U Murthy Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/b6b0143a8a57bd58352ad35e08c25424c879c0cb.1425037853.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 44 +++++++++++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 13 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index a41749543d48..e20232c3320a 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -32,15 +32,31 @@ enum clock_event_nofitiers { struct clock_event_device; struct module; -/* Clock event mode commands */ +/* Clock event mode commands for legacy ->set_mode(): OBSOLETE */ enum clock_event_mode { CLOCK_EVT_MODE_UNUSED = 0, CLOCK_EVT_MODE_SHUTDOWN, CLOCK_EVT_MODE_PERIODIC, CLOCK_EVT_MODE_ONESHOT, CLOCK_EVT_MODE_RESUME, +}; - /* Legacy ->set_mode() callback doesn't support below modes */ +/* + * Possible states of a clock event device. + * + * DETACHED: Device is not used by clockevents core. Initial state or can be + * reached from SHUTDOWN. + * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT. + * PERIODIC: Device is programmed to generate events periodically. Can be + * reached from DETACHED or SHUTDOWN. + * ONESHOT: Device is programmed to generate event only once. Can be reached + * from DETACHED or SHUTDOWN. + */ +enum clock_event_state { + CLOCK_EVT_STATE_DETACHED = 0, + CLOCK_EVT_STATE_SHUTDOWN, + CLOCK_EVT_STATE_PERIODIC, + CLOCK_EVT_STATE_ONESHOT, }; /* @@ -80,13 +96,14 @@ enum clock_event_mode { * @min_delta_ns: minimum delta value in ns * @mult: nanosecond to cycles multiplier * @shift: nanoseconds to cycles divisor (power of two) - * @mode: operating mode assigned by the management code + * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE + * @state: current state of the device, assigned by the core code * @features: features * @retries: number of forced programming retries * @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_state_periodic: switch state to periodic, if !set_mode + * @set_state_oneshot: switch state to oneshot, if !set_mode + * @set_state_shutdown: switch state to shutdown, if !set_mode * @tick_resume: resume clkevt device, if !set_mode * @broadcast: function to broadcast events * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration @@ -111,20 +128,21 @@ struct clock_event_device { u32 mult; u32 shift; enum clock_event_mode mode; + enum clock_event_state state; unsigned int features; unsigned long retries; /* - * Mode transition callback(s): Only one of the two groups should be + * State 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}(). + * - set_state_{shutdown|periodic|oneshot}(), tick_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_state_periodic)(struct clock_event_device *); + int (*set_state_oneshot)(struct clock_event_device *); + int (*set_state_shutdown)(struct clock_event_device *); int (*tick_resume)(struct clock_event_device *); void (*broadcast)(const struct cpumask *mask); @@ -177,8 +195,8 @@ extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); extern void clockevents_exchange_device(struct clock_event_device *old, struct clock_event_device *new); -extern void clockevents_set_mode(struct clock_event_device *dev, - enum clock_event_mode mode); +extern void clockevents_set_state(struct clock_event_device *dev, + enum clock_event_state state); extern int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, bool force); -- cgit v1.2.3 From 9f083b74df3a7eaa100b456f2dc195512daf728e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 25 Mar 2015 13:05:19 +0100 Subject: clockevents: Remove CONFIG_GENERIC_CLOCKEVENTS_BUILD This option was for simpler migration to the clock events code. Most architectures have been converted and the option has been disfunctional as a standalone option for quite some time. Remove it. Signed-off-by: Thomas Gleixner Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/5021859.jl9OC1medj@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index e20232c3320a..57975131dac1 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -22,7 +22,7 @@ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_CPU_DEAD, }; -#ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD +#ifdef CONFIG_GENERIC_CLOCKEVENTS #include #include @@ -229,13 +229,9 @@ static inline int tick_check_broadcast_expired(void) { return 0; } static inline void tick_setup_hrtimer_broadcast(void) {}; #endif -#ifdef CONFIG_GENERIC_CLOCKEVENTS extern int clockevents_notify(unsigned long reason, void *arg); -#else -static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } -#endif -#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */ +#else /* CONFIG_GENERIC_CLOCKEVENTS */ static inline void clockevents_suspend(void) {} static inline void clockevents_resume(void) {} @@ -243,6 +239,7 @@ static inline void clockevents_resume(void) {} static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } static inline int tick_check_broadcast_expired(void) { return 0; } static inline void tick_setup_hrtimer_broadcast(void) {}; +static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } #endif -- cgit v1.2.3 From c1797baf6880174f899ce3960d0598f5bbeeb7ff Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 25 Mar 2015 13:07:37 +0100 Subject: tick: Move core only declarations and functions to core No point to expose everything to the world. People just believe such functions can be abused for whatever purposes. Sigh. Signed-off-by: Thomas Gleixner [ Rebased on top of 4.0-rc5 ] Signed-off-by: Rafael J. Wysocki Cc: Nicolas Pitre Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/28017337.VbCUc39Gme@vostro.rjw.lan [ Merged to latest timers/core ] Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 57975131dac1..bc3af821350b 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -193,15 +193,6 @@ extern void clockevents_config_and_register(struct clock_event_device *dev, extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); -extern void clockevents_exchange_device(struct clock_event_device *old, - struct clock_event_device *new); -extern void clockevents_set_state(struct clock_event_device *dev, - enum clock_event_state state); -extern int clockevents_program_event(struct clock_event_device *dev, - ktime_t expires, bool force); - -extern void clockevents_handle_noop(struct clock_event_device *dev); - static inline void clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) { @@ -209,6 +200,12 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) freq, minsec); } +/* Should be core only, but is abused by arm bl_switcher */ +extern void clockevents_set_state(struct clock_event_device *dev, + enum clock_event_state state); +extern int clockevents_program_event(struct clock_event_device *dev, + ktime_t expires, bool force); + extern void clockevents_suspend(void); extern void clockevents_resume(void); -- cgit v1.2.3 From 4ffee521f36390c7720d493591b764ca35c8030b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 25 Mar 2015 13:09:16 +0100 Subject: clockevents: Make suspend/resume calls explicit clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the suspend/resume() calls and invoke them directly from the call sites. No locking required at this point because these calls happen with interrupts disabled and a single cpu online. Signed-off-by: Thomas Gleixner [ Rebased on top of 4.0-rc5. ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/713674030.jVm1qaHuPf@vostro.rjw.lan [ Rebased on top of latest timers/core. ] Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index bc3af821350b..50ce9750754f 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -16,8 +16,6 @@ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_BROADCAST_FORCE, CLOCK_EVT_NOTIFY_BROADCAST_ENTER, CLOCK_EVT_NOTIFY_BROADCAST_EXIT, - CLOCK_EVT_NOTIFY_SUSPEND, - CLOCK_EVT_NOTIFY_RESUME, CLOCK_EVT_NOTIFY_CPU_DYING, CLOCK_EVT_NOTIFY_CPU_DEAD, }; -- cgit v1.2.3 From 7270d11c56f594af4d166b2988421cd8ed933dc1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 25 Mar 2015 13:11:52 +0100 Subject: arm/bL_switcher: Kill tick suspend hackery Use the new tick_suspend/resume_local() and get rid of the homebrewn implementation of these in the ARM bL switcher. The check for the cpumask is completely pointless. There is no harm to suspend a per cpu tick device unconditionally. If that's a real issue then we fix it proper at the core level and not with some completely undocumented hacks in some random core code. Move the tick internals to the core code, now that this nuisance is gone. Signed-off-by: Thomas Gleixner [ rjw: Rebase, changelog ] Signed-off-by: Rafael J. Wysocki Cc: Nicolas Pitre Cc: Peter Zijlstra Cc: Russell King Link: http://lkml.kernel.org/r/1655112.Ws17YsMfN7@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 50ce9750754f..3ac7e2d90374 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -198,12 +198,6 @@ clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) freq, minsec); } -/* Should be core only, but is abused by arm bl_switcher */ -extern void clockevents_set_state(struct clock_event_device *dev, - enum clock_event_state state); -extern int clockevents_program_event(struct clock_event_device *dev, - ktime_t expires, bool force); - extern void clockevents_suspend(void); extern void clockevents_resume(void); -- cgit v1.2.3 From 9eed56e889d8a0bb7870e1216d8d4326dd63ec50 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 2 Apr 2015 11:26:23 +0200 Subject: clockevents: Clean up clockchips.h Do various cleanups on the clockchips.h file: - indent preprocessor blocks to make it more clear which block we are in, this also makes merge resolution easier - comment larger preprocessor blocks consistently, using the: #if FOO ... #else /* !FOO: */ ... #endif /* !FOO */ notation. - unbreak lines - etc. No change in functionality. Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 87 ++++++++++++++++++++++------------------------ 1 file changed, 41 insertions(+), 46 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 3ac7e2d90374..caeca76d7b32 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -22,17 +22,17 @@ enum clock_event_nofitiers { #ifdef CONFIG_GENERIC_CLOCKEVENTS -#include -#include -#include -#include +# include +# include +# include +# include struct clock_event_device; struct module; /* Clock event mode commands for legacy ->set_mode(): OBSOLETE */ enum clock_event_mode { - CLOCK_EVT_MODE_UNUSED = 0, + CLOCK_EVT_MODE_UNUSED, CLOCK_EVT_MODE_SHUTDOWN, CLOCK_EVT_MODE_PERIODIC, CLOCK_EVT_MODE_ONESHOT, @@ -51,7 +51,7 @@ enum clock_event_mode { * from DETACHED or SHUTDOWN. */ enum clock_event_state { - CLOCK_EVT_STATE_DETACHED = 0, + CLOCK_EVT_STATE_DETACHED, CLOCK_EVT_STATE_SHUTDOWN, CLOCK_EVT_STATE_PERIODIC, CLOCK_EVT_STATE_ONESHOT, @@ -60,28 +60,29 @@ enum clock_event_state { /* * Clock event features */ -#define CLOCK_EVT_FEAT_PERIODIC 0x000001 -#define CLOCK_EVT_FEAT_ONESHOT 0x000002 -#define CLOCK_EVT_FEAT_KTIME 0x000004 +# define CLOCK_EVT_FEAT_PERIODIC 0x000001 +# define CLOCK_EVT_FEAT_ONESHOT 0x000002 +# define CLOCK_EVT_FEAT_KTIME 0x000004 + /* - * x86(64) specific misfeatures: + * x86(64) specific (mis)features: * * - Clockevent source stops in C3 State and needs broadcast support. * - Local APIC timer is used as a dummy device. */ -#define CLOCK_EVT_FEAT_C3STOP 0x000008 -#define CLOCK_EVT_FEAT_DUMMY 0x000010 +# define CLOCK_EVT_FEAT_C3STOP 0x000008 +# define CLOCK_EVT_FEAT_DUMMY 0x000010 /* * Core shall set the interrupt affinity dynamically in broadcast mode */ -#define CLOCK_EVT_FEAT_DYNIRQ 0x000020 -#define CLOCK_EVT_FEAT_PERCPU 0x000040 +# define CLOCK_EVT_FEAT_DYNIRQ 0x000020 +# define CLOCK_EVT_FEAT_PERCPU 0x000040 /* * Clockevent device is based on a hrtimer for broadcast */ -#define CLOCK_EVT_FEAT_HRTIMER 0x000080 +# define CLOCK_EVT_FEAT_HRTIMER 0x000080 /** * struct clock_event_device - clock event device descriptor @@ -116,10 +117,8 @@ enum clock_event_state { */ struct clock_event_device { void (*event_handler)(struct clock_event_device *); - int (*set_next_event)(unsigned long evt, - struct clock_event_device *); - int (*set_next_ktime)(ktime_t expires, - struct clock_event_device *); + int (*set_next_event)(unsigned long evt, struct clock_event_device *); + int (*set_next_ktime)(ktime_t expires, struct clock_event_device *); ktime_t next_event; u64 max_delta_ns; u64 min_delta_ns; @@ -136,8 +135,7 @@ struct clock_event_device { * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. * - set_state_{shutdown|periodic|oneshot}(), tick_resume(). */ - void (*set_mode)(enum clock_event_mode mode, - struct clock_event_device *); + void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); int (*set_state_periodic)(struct clock_event_device *); int (*set_state_oneshot)(struct clock_event_device *); int (*set_state_shutdown)(struct clock_event_device *); @@ -169,18 +167,18 @@ struct clock_event_device { * * factor = (clock_ticks << shift) / nanoseconds */ -static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec, - int shift) +static inline unsigned long +div_sc(unsigned long ticks, unsigned long nsec, int shift) { - uint64_t tmp = ((uint64_t)ticks) << shift; + u64 tmp = ((u64)ticks) << shift; do_div(tmp, nsec); + return (unsigned long) tmp; } /* Clock event layer functions */ -extern u64 clockevent_delta2ns(unsigned long latch, - struct clock_event_device *evt); +extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); extern void clockevents_register_device(struct clock_event_device *dev); extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); @@ -194,42 +192,39 @@ extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); static inline void clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec) { - return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, - freq, minsec); + return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, minsec); } extern void clockevents_suspend(void); extern void clockevents_resume(void); -#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST -#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST +# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +# ifdef CONFIG_ARCH_HAS_TICK_BROADCAST extern void tick_broadcast(const struct cpumask *mask); -#else -#define tick_broadcast NULL -#endif +# else +# define tick_broadcast NULL +# endif extern int tick_receive_broadcast(void); -#endif +# endif -#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) +# if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) extern void tick_setup_hrtimer_broadcast(void); extern int tick_check_broadcast_expired(void); -#else +# else static inline int tick_check_broadcast_expired(void) { return 0; } -static inline void tick_setup_hrtimer_broadcast(void) {}; -#endif +static inline void tick_setup_hrtimer_broadcast(void) { } +# endif extern int clockevents_notify(unsigned long reason, void *arg); -#else /* CONFIG_GENERIC_CLOCKEVENTS */ - -static inline void clockevents_suspend(void) {} -static inline void clockevents_resume(void) {} +#else /* !CONFIG_GENERIC_CLOCKEVENTS: */ +static inline void clockevents_suspend(void) { } +static inline void clockevents_resume(void) { } static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } static inline int tick_check_broadcast_expired(void) { return 0; } -static inline void tick_setup_hrtimer_broadcast(void) {}; -static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; } +static inline void tick_setup_hrtimer_broadcast(void) { } -#endif +#endif /* !CONFIG_GENERIC_CLOCKEVENTS */ -#endif +#endif /* _LINUX_CLOCKCHIPS_H */ -- cgit v1.2.3 From 89feddbfe7023ccfb4a6d7f5e3f5161d91b28b18 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 3 Apr 2015 02:03:42 +0200 Subject: clockevents: Remove the broadcast control leftovers All users converted. Remove the notify leftovers. Signed-off-by: Thomas Gleixner Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/2076318.76XJZ8QYP3@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index caeca76d7b32..438fafa75067 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -11,9 +11,6 @@ /* Clock event notification values */ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_BROADCAST_ON, - CLOCK_EVT_NOTIFY_BROADCAST_OFF, - CLOCK_EVT_NOTIFY_BROADCAST_FORCE, CLOCK_EVT_NOTIFY_BROADCAST_ENTER, CLOCK_EVT_NOTIFY_BROADCAST_EXIT, CLOCK_EVT_NOTIFY_CPU_DYING, -- cgit v1.2.3 From ffa48c0d76803057ee89bf220305466d74256d7b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 Apr 2015 02:36:10 +0200 Subject: clockevents: Remove broadcast oneshot control leftovers Now that all users are converted over to explicit calls into the clockevents state machine, remove the notification chain leftovers. Original-from: Thomas Gleixner Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Cc: Linus Torvalds Cc: Andrew Morton Cc: John Stultz Link: http://lkml.kernel.org/r/14018863.NQUzkFuafr@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 438fafa75067..f97f498a5d10 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -11,8 +11,6 @@ /* Clock event notification values */ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_BROADCAST_ENTER, - CLOCK_EVT_NOTIFY_BROADCAST_EXIT, CLOCK_EVT_NOTIFY_CPU_DYING, CLOCK_EVT_NOTIFY_CPU_DEAD, }; -- cgit v1.2.3 From 52c063d1adbc16c76e70fffa20727fcd4e9343b3 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 3 Apr 2015 02:37:24 +0200 Subject: clockevents: Make tick handover explicit clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the tick_handover call and invoke it explicitely from the hotplug code. Temporary solution will be cleaned up in later patches. Signed-off-by: Thomas Gleixner [ Rebase ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Cc: John Stultz Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index f97f498a5d10..f4bde22f8a05 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -11,7 +11,6 @@ /* Clock event notification values */ enum clock_event_nofitiers { CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_CPU_DYING, CLOCK_EVT_NOTIFY_CPU_DEAD, }; -- cgit v1.2.3 From a49b116dcb1265f238f3169507424257b0519069 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 3 Apr 2015 02:38:05 +0200 Subject: clockevents: Cleanup dead cpu explicitely clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the cleanup function for a dead cpu and invoke it directly from the cpu down code. Make it conditional on CPU_HOTPLUG as well. Temporary change, will be refined in the future. Signed-off-by: Thomas Gleixner [ Rebased, added clockevents_notify() removal ] Signed-off-by: Rafael J. Wysocki Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan Signed-off-by: Ingo Molnar --- include/linux/clockchips.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index f4bde22f8a05..96c280b2c263 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -8,12 +8,6 @@ #ifndef _LINUX_CLOCKCHIPS_H #define _LINUX_CLOCKCHIPS_H -/* Clock event notification values */ -enum clock_event_nofitiers { - CLOCK_EVT_NOTIFY_ADD, - CLOCK_EVT_NOTIFY_CPU_DEAD, -}; - #ifdef CONFIG_GENERIC_CLOCKEVENTS # include -- cgit v1.2.3 From 8fff52fd50934580c5108afed12043a774edf728 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 3 Apr 2015 09:04:04 +0530 Subject: clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state When no timers/hrtimers are pending, the expiry time is set to a special value: 'KTIME_MAX'. This normally happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes. When 'expiry == KTIME_MAX', we either cancel the 'tick-sched' hrtimer (NOHZ_MODE_HIGHRES) or skip reprogramming clockevent device (NOHZ_MODE_LOWRES). But, the clockevent device is already reprogrammed from the tick-handler for next tick. As the clock event device is programmed in ONESHOT mode it will at least fire one more time (unnecessarily). Timers on few implementations (like arm_arch_timer, etc.) only support PERIODIC mode and their drivers emulate ONESHOT over that. Which means that on these platforms we will get spurious interrupts periodically (at last programmed interval rate, normally tick rate). In order to avoid spurious interrupts, the clockevent device should be stopped or its interrupts should be masked. A simple (yet hacky) solution to get this fixed could be: update hrtimer_force_reprogram() to always reprogram clockevent device and update clockevent drivers to STOP generating events (or delay it to max time) when 'expires' is set to KTIME_MAX. But the drawback here is that every clockevent driver has to be hacked for this particular case and its very easy for new ones to miss this. However, Thomas suggested to add an optional state ONESHOT_STOPPED to solve this problem: lkml.org/lkml/2014/5/9/508. This patch adds support for ONESHOT_STOPPED state in clockevents core. It will only be available to drivers that implement the state-specific callbacks instead of the legacy ->set_mode() callback. Signed-off-by: Viresh Kumar Reviewed-by: Preeti U. Murthy Cc: linaro-kernel@lists.linaro.org Cc: Frederic Weisbecker Cc: Kevin Hilman Cc: Daniel Lezcano Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/b8b383a03ac07b13312c16850b5106b82e4245b5.1428031396.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner --- include/linux/clockchips.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 96c280b2c263..271fa4c8eb29 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -37,12 +37,15 @@ enum clock_event_mode { * reached from DETACHED or SHUTDOWN. * ONESHOT: Device is programmed to generate event only once. Can be reached * from DETACHED or SHUTDOWN. + * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily + * stopped. */ enum clock_event_state { CLOCK_EVT_STATE_DETACHED, CLOCK_EVT_STATE_SHUTDOWN, CLOCK_EVT_STATE_PERIODIC, CLOCK_EVT_STATE_ONESHOT, + CLOCK_EVT_STATE_ONESHOT_STOPPED, }; /* @@ -90,6 +93,7 @@ enum clock_event_state { * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. * @set_state_periodic: switch state to periodic, if !set_mode * @set_state_oneshot: switch state to oneshot, if !set_mode + * @set_state_oneshot_stopped: switch state to oneshot_stopped, if !set_mode * @set_state_shutdown: switch state to shutdown, if !set_mode * @tick_resume: resume clkevt device, if !set_mode * @broadcast: function to broadcast events @@ -121,11 +125,12 @@ struct clock_event_device { * State transition callback(s): Only one of the two groups should be * defined: * - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME. - * - set_state_{shutdown|periodic|oneshot}(), tick_resume(). + * - set_state_{shutdown|periodic|oneshot|oneshot_stopped}(), tick_resume(). */ void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); int (*set_state_periodic)(struct clock_event_device *); int (*set_state_oneshot)(struct clock_event_device *); + int (*set_state_oneshot_stopped)(struct clock_event_device *); int (*set_state_shutdown)(struct clock_event_device *); int (*tick_resume)(struct clock_event_device *); -- cgit v1.2.3 From 3434d23b694e5cb6e44e966914563406c31c4053 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 21 May 2015 13:33:45 +0530 Subject: clockevents: Add helpers to check the state of a clockevent device Some clockevent drivers, once migrated to use per-state callbacks, need to check the state of the clockevent device in their callbacks or interrupt handler. Add accessor functions clockevent_state_*() to get this information. Signed-off-by: Viresh Kumar Cc: linaro-kernel@lists.linaro.org Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/04a717d490335c688dd7af899fbcede97e1bb8ee.1432192527.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner --- include/linux/clockchips.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 271fa4c8eb29..64214ad85af9 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -149,6 +149,32 @@ struct clock_event_device { struct module *owner; } ____cacheline_aligned; +/* Helpers to verify state of a clockevent device */ +static inline bool clockevent_state_detached(struct clock_event_device *dev) +{ + return dev->state == CLOCK_EVT_STATE_DETACHED; +} + +static inline bool clockevent_state_shutdown(struct clock_event_device *dev) +{ + return dev->state == CLOCK_EVT_STATE_SHUTDOWN; +} + +static inline bool clockevent_state_periodic(struct clock_event_device *dev) +{ + return dev->state == CLOCK_EVT_STATE_PERIODIC; +} + +static inline bool clockevent_state_oneshot(struct clock_event_device *dev) +{ + return dev->state == CLOCK_EVT_STATE_ONESHOT; +} + +static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev) +{ + return dev->state == CLOCK_EVT_STATE_ONESHOT_STOPPED; +} + /* * Calculate a multiplication factor for scaled math, which is used to convert * nanoseconds based values to clock ticks: -- cgit v1.2.3 From be3ef76e9d9b97962c70bd6351787d29071ae481 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 2 Jun 2015 14:30:11 +0200 Subject: clockevents: Rename state to state_use_accessors The only sensible way to make abuse of core internal fields obvious and easy to grep for. Signed-off-by: Thomas Gleixner Cc: Viresh Kumar Cc: Peter Zijlstra --- include/linux/clockchips.h | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 64214ad85af9..597a1e836f22 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -87,7 +87,7 @@ enum clock_event_state { * @mult: nanosecond to cycles multiplier * @shift: nanoseconds to cycles divisor (power of two) * @mode: operating mode, relevant only to ->set_mode(), OBSOLETE - * @state: current state of the device, assigned by the core code + * @state_use_accessors:current state of the device, assigned by the core code * @features: features * @retries: number of forced programming retries * @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME. @@ -117,7 +117,7 @@ struct clock_event_device { u32 mult; u32 shift; enum clock_event_mode mode; - enum clock_event_state state; + enum clock_event_state state_use_accessors; unsigned int features; unsigned long retries; @@ -152,27 +152,27 @@ struct clock_event_device { /* Helpers to verify state of a clockevent device */ static inline bool clockevent_state_detached(struct clock_event_device *dev) { - return dev->state == CLOCK_EVT_STATE_DETACHED; + return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED; } static inline bool clockevent_state_shutdown(struct clock_event_device *dev) { - return dev->state == CLOCK_EVT_STATE_SHUTDOWN; + return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN; } static inline bool clockevent_state_periodic(struct clock_event_device *dev) { - return dev->state == CLOCK_EVT_STATE_PERIODIC; + return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC; } static inline bool clockevent_state_oneshot(struct clock_event_device *dev) { - return dev->state == CLOCK_EVT_STATE_ONESHOT; + return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT; } static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev) { - return dev->state == CLOCK_EVT_STATE_ONESHOT_STOPPED; + return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED; } /* -- cgit v1.2.3