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path: root/drivers/clocksource/dummy_timer.c
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2016-07-15clocksource/dummy_timer: Convert to hotplug state machineRichard Cochran
Install the callbacks via the state machine and let the core invoke the callbacks on the already online CPUs. Signed-off-by: Richard Cochran <rcochran@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153336.130385842@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-10clockevents/drivers/dummy_timer: Migrate to new 'set-state' interfaceViresh Kumar
Migrate dummy_timer driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. We weren't doing anything in the ->set_mode() callback. So, this patch doesn't provide any set-state callbacks. Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Viresh Kumae <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2014-08-26time: Replace __get_cpu_var usesChristoph Lameter
Convert uses of __get_cpu_var for creating a address from a percpu offset to this_cpu_ptr. The two cases where get_cpu_var is used to actually access a percpu variable are changed to use this_cpu_read/raw_cpu_read. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-03-20clocksource, dummy-timer: Fix CPU hotplug callback registrationSrivatsa S. Bhat
Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the clocksource dummy-timer code by using this latter form of callback registration. Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-14clocksource+irqchip: delete __cpuinit usage from all related filesPaul Gortmaker
The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/clocksource and drivers/irqchip uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-06-24clocksource: Add generic dummy timer driverMark Rutland
Several architectures have a dummy timer driver tightly coupled with their broadcast code to support machines without cpu-local timers (or where there is a lack of driver support). Since 12ad100046: "clockevents: Add generic timer broadcast function" it's been possible to write broadcast-capable timer drivers decoupled from the broadcast mechanism. We can use this functionality to implement a generic dummy timer driver that can be shared by all architectures with generic tick broadcast (ARCH_HAS_TICK_BROADCAST). This patch implements a generic dummy timer using this facility. [sboyd: Make percpu data static, use __this_cpu_ptr(), move to early_initcall to properly register on each CPU, only register if more than one CPU possible] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>, Cc: John Stultz <john.stultz@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1370291642-13259-3-git-send-email-sboyd@codeaurora.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>