From 847b2f42be203f3cff7f243fdd3ee50c1e06c882 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 18 May 2011 21:33:41 +0000 Subject: clockevents: Restructure clock_event_device members Group the hot path members of struct clock_event_device together so we have a better cache line footprint. Make it cacheline aligned. Signed-off-by: Thomas Gleixner Cc: John Stultz Reviewed-by: Ingo Molnar Link: http://lkml.kernel.org/r/%3C20110518210136.223607682%40linutronix.de%3E --- include/linux/clockchips.h | 45 +++++++++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 22 deletions(-) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index fc53492b6ad7..9466eebc8e19 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -56,46 +56,47 @@ enum clock_event_nofitiers { /** * struct clock_event_device - clock event device descriptor - * @name: ptr to clock event name - * @features: features + * @event_handler: Assigned by the framework to be called by the low + * level handler of the event source + * @set_next_event: set next event function + * @next_event: local storage for the next event in oneshot mode * @max_delta_ns: maximum delta value in ns * @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 + * @features: features + * @retries: number of forced programming retries + * @set_mode: set mode function + * @broadcast: function to broadcast events + * @name: ptr to clock event name * @rating: variable to rate clock event devices * @irq: IRQ number (only for non CPU local devices) * @cpumask: cpumask to indicate for which CPUs this device works - * @set_next_event: set next event function - * @set_mode: set mode function - * @event_handler: Assigned by the framework to be called by the low - * level handler of the event source - * @broadcast: function to broadcast events * @list: list head for the management code - * @mode: operating mode assigned by the management code - * @next_event: local storage for the next event in oneshot mode - * @retries: number of forced programming retries */ struct clock_event_device { - const char *name; - unsigned int features; + void (*event_handler)(struct clock_event_device *); + int (*set_next_event)(unsigned long evt, + struct clock_event_device *); + ktime_t next_event; u64 max_delta_ns; u64 min_delta_ns; u32 mult; u32 shift; + enum clock_event_mode mode; + unsigned int features; + unsigned long retries; + + void (*broadcast)(const struct cpumask *mask); + void (*set_mode)(enum clock_event_mode mode, + struct clock_event_device *); + const char *name; int rating; int irq; const struct cpumask *cpumask; - int (*set_next_event)(unsigned long evt, - struct clock_event_device *); - void (*set_mode)(enum clock_event_mode mode, - struct clock_event_device *); - void (*event_handler)(struct clock_event_device *); - void (*broadcast)(const struct cpumask *mask); struct list_head list; - enum clock_event_mode mode; - ktime_t next_event; - unsigned long retries; -}; +} ____cacheline_aligned; /* * Calculate a multiplication factor for scaled math, which is used to convert -- cgit v1.2.3-71-gd317 From 57f0fcbe1dea8a36c9d1673086326059991c5f81 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 18 May 2011 21:33:41 +0000 Subject: clockevents: Provide combined configure and register function All clockevent devices have the same open coded initialization functions. Provide an interface which does all necessary initialization in the core code. Signed-off-by: Thomas Gleixner Cc: John Stultz Reviewed-by: Ingo Molnar Link: http://lkml.kernel.org/r/%3C20110518210136.331975870%40linutronix.de%3E --- include/linux/clockchips.h | 9 +++++++++ kernel/time/clockevents.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 9466eebc8e19..80acc79e0dc5 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -69,6 +69,8 @@ enum clock_event_nofitiers { * @retries: number of forced programming retries * @set_mode: set mode function * @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 * @name: ptr to clock event name * @rating: variable to rate clock event devices * @irq: IRQ number (only for non CPU local devices) @@ -91,6 +93,9 @@ struct clock_event_device { void (*broadcast)(const struct cpumask *mask); void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); + unsigned long min_delta_ticks; + unsigned long max_delta_ticks; + const char *name; int rating; int irq; @@ -123,6 +128,10 @@ extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); extern void clockevents_register_device(struct clock_event_device *dev); +extern void clockevents_config_and_register(struct clock_event_device *dev, + u32 freq, unsigned long min_delta, + unsigned long max_delta); + 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, diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 0d74b9ba90c8..c69e88c94446 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -194,6 +194,50 @@ void clockevents_register_device(struct clock_event_device *dev) } EXPORT_SYMBOL_GPL(clockevents_register_device); +static void clockevents_config(struct clock_event_device *dev, + u32 freq) +{ + unsigned long sec; + + if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) + return; + + /* + * Calculate the maximum number of seconds we can sleep. Limit + * to 10 minutes for hardware which can program more than + * 32bit ticks so we still get reasonable conversion values. + */ + sec = dev->max_delta_ticks; + do_div(sec, freq); + if (!sec) + sec = 1; + else if (sec > 600 && dev->max_delta_ticks > UINT_MAX) + sec = 600; + + clockevents_calc_mult_shift(dev, freq, sec); + dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev); + dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev); +} + +/** + * clockevents_config_and_register - Configure and register a clock event device + * @dev: device to register + * @freq: The clock frequency + * @min_delta: The minimum clock ticks to program in oneshot mode + * @max_delta: The maximum clock ticks to program in oneshot mode + * + * min/max_delta can be 0 for devices which do not support oneshot mode. + */ +void clockevents_config_and_register(struct clock_event_device *dev, + u32 freq, unsigned long min_delta, + unsigned long max_delta) +{ + dev->min_delta_ticks = min_delta; + dev->max_delta_ticks = max_delta; + clockevents_config(dev, freq); + clockevents_register_device(dev); +} + /* * Noop handler when we shut down an event device */ -- cgit v1.2.3-71-gd317 From 80b816b736cfa5b9582279127099b20a479ab7d9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 18 May 2011 21:33:42 +0000 Subject: clockevents: Provide interface to reconfigure an active clock event device Some ARM SoCs have clock event devices which have their frequency modified due to frequency scaling. Provide an interface which allows to reconfigure an active device. After reconfiguration reprogram the current pending event. Signed-off-by: Thomas Gleixner Cc: LAK Cc: John Stultz Acked-by: Linus Walleij Reviewed-by: Ingo Molnar Link: http://lkml.kernel.org/r/%3C20110518210136.437459958%40linutronix.de%3E --- include/linux/clockchips.h | 2 ++ kernel/time/clockevents.c | 20 ++++++++++++++++++++ 2 files changed, 22 insertions(+) (limited to 'include/linux/clockchips.h') diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 80acc79e0dc5..d6733e27af34 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -132,6 +132,8 @@ extern void clockevents_config_and_register(struct clock_event_device *dev, u32 freq, unsigned long min_delta, unsigned long max_delta); +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, diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index c69e88c94446..22a9da9a9c96 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -238,6 +238,26 @@ void clockevents_config_and_register(struct clock_event_device *dev, clockevents_register_device(dev); } +/** + * clockevents_update_freq - Update frequency and reprogram a clock event device. + * @dev: device to modify + * @freq: new device frequency + * + * Reconfigure and reprogram a clock event device in oneshot + * mode. Must be called on the cpu for which the device delivers per + * cpu timer events with interrupts disabled! Returns 0 on success, + * -ETIME when the event is in the past. + */ +int clockevents_update_freq(struct clock_event_device *dev, u32 freq) +{ + clockevents_config(dev, freq); + + if (dev->mode != CLOCK_EVT_MODE_ONESHOT) + return 0; + + return clockevents_program_event(dev, dev->next_event, ktime_get()); +} + /* * Noop handler when we shut down an event device */ -- cgit v1.2.3-71-gd317