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 --- kernel/time/timer_list.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) (limited to 'kernel/time/timer_list.c') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 61ed862cdd37..2cfd19485824 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -228,9 +228,35 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) print_name_offset(m, dev->set_next_event); SEQ_printf(m, "\n"); - SEQ_printf(m, " set_mode: "); - print_name_offset(m, dev->set_mode); - SEQ_printf(m, "\n"); + if (dev->set_mode) { + SEQ_printf(m, " set_mode: "); + print_name_offset(m, dev->set_mode); + SEQ_printf(m, "\n"); + } else { + if (dev->set_mode_shutdown) { + SEQ_printf(m, " shutdown: "); + print_name_offset(m, dev->set_mode_shutdown); + SEQ_printf(m, "\n"); + } + + if (dev->set_mode_periodic) { + SEQ_printf(m, " periodic: "); + print_name_offset(m, dev->set_mode_periodic); + SEQ_printf(m, "\n"); + } + + if (dev->set_mode_oneshot) { + SEQ_printf(m, " oneshot: "); + print_name_offset(m, dev->set_mode_oneshot); + SEQ_printf(m, "\n"); + } + + if (dev->set_mode_resume) { + SEQ_printf(m, " resume: "); + print_name_offset(m, dev->set_mode_resume); + SEQ_printf(m, "\n"); + } + } SEQ_printf(m, " event_handler: "); print_name_offset(m, dev->event_handler); -- 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 --- kernel/time/timer_list.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/time/timer_list.c') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 2cfd19485824..2b3e9393034d 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -251,9 +251,9 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) SEQ_printf(m, "\n"); } - if (dev->set_mode_resume) { + if (dev->tick_resume) { SEQ_printf(m, " resume: "); - print_name_offset(m, dev->set_mode_resume); + print_name_offset(m, dev->tick_resume); SEQ_printf(m, "\n"); } } -- 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 --- kernel/time/timer_list.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel/time/timer_list.c') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 2b3e9393034d..05aa5590106a 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -233,21 +233,21 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) print_name_offset(m, dev->set_mode); SEQ_printf(m, "\n"); } else { - if (dev->set_mode_shutdown) { + if (dev->set_state_shutdown) { SEQ_printf(m, " shutdown: "); - print_name_offset(m, dev->set_mode_shutdown); + print_name_offset(m, dev->set_state_shutdown); SEQ_printf(m, "\n"); } - if (dev->set_mode_periodic) { + if (dev->set_state_periodic) { SEQ_printf(m, " periodic: "); - print_name_offset(m, dev->set_mode_periodic); + print_name_offset(m, dev->set_state_periodic); SEQ_printf(m, "\n"); } - if (dev->set_mode_oneshot) { + if (dev->set_state_oneshot) { SEQ_printf(m, " oneshot: "); - print_name_offset(m, dev->set_mode_oneshot); + print_name_offset(m, dev->set_state_oneshot); SEQ_printf(m, "\n"); } -- 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 --- kernel/time/timer_list.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/timer_list.c') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 05aa5590106a..e878c2e0ba45 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -16,10 +16,10 @@ #include #include #include -#include #include +#include "tick-internal.h" struct timer_list_iter { int cpu; -- cgit v1.2.3