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* tick: Sanitize broadcast control logicThomas Gleixner2013-07-022-12/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent implementation of a generic dummy timer resulted in a different registration order of per cpu local timers which made the broadcast control logic go belly up. If the dummy timer is the first clock event device which is registered for a CPU, then it is installed, the broadcast timer is initialized and the CPU is marked as broadcast target. If a real clock event device is installed after that, we can fail to take the CPU out of the broadcast mask. In the worst case we end up with two periodic timer events firing for the same CPU. One from the per cpu hardware device and one from the broadcast. Now the problem is that we have no way to distinguish whether the system is in a state which makes broadcasting necessary or the broadcast bit was set due to the nonfunctional dummy timer installment. To solve this we need to keep track of the system state seperately and provide a more detailed decision logic whether we keep the CPU in broadcast mode or not. The old decision logic only clears the broadcast mode, if the newly installed clock event device is not affected by power states. The new logic clears the broadcast mode if one of the following is true: - The new device is not affected by power states. - The system is not in a power state affected mode - The system has switched to oneshot mode. The oneshot broadcast is controlled from the deep idle state. The CPU is not in idle at this point, so it's safe to remove it from the mask. If we clear the broadcast bit for the CPU when a new device is installed, we also shutdown the broadcast device when this was the last CPU in the broadcast mask. If the broadcast bit is kept, then we leave the new device in shutdown state and rely on the broadcast to deliver the timer interrupts via the broadcast ipis. Reported-and-tested-by: Stehle Vincent-B46079 <B46079@freescale.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Cc: John Stultz <john.stultz@linaro.org>, Cc: Mark Rutland <mark.rutland@arm.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307012153060.4013@ionos.tec.linutronix.de Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* tick: Prevent uncontrolled switch to oneshot modeThomas Gleixner2013-07-021-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the system switches from periodic to oneshot mode, the broadcast logic causes a possibility that a CPU which has not yet switched to oneshot mode puts its own clock event device into oneshot mode without updating the state and the timer handler. CPU0 CPU1 per cpu tickdev is in periodic mode and switched to broadcast Switch to oneshot mode tick_broadcast_switch_to_oneshot() cpumask_copy(tick_oneshot_broacast_mask, tick_broadcast_mask); broadcast device mode = oneshot Timer interrupt irq_enter() tick_check_oneshot_broadcast() dev->set_mode(ONESHOT); tick_handle_periodic() if (dev->mode == ONESHOT) dev->next_event += period; FAIL. We fail, because dev->next_event contains KTIME_MAX, if the device was in periodic mode before the uncontrolled switch to oneshot happened. We must copy the broadcast bits over to the oneshot mask, because otherwise a CPU which relies on the broadcast would not been woken up anymore after the broadcast device switched to oneshot mode. So we need to verify in tick_check_oneshot_broadcast() whether the CPU has already switched to oneshot mode. If not, leave the device untouched and let the CPU switch controlled into oneshot mode. This is a long standing bug, which was never noticed, because the main user of the broadcast x86 cannot run into that scenario, AFAICT. The nonarchitected timer mess of ARM creates a gazillion of differently broken abominations which trigger the shortcomings of that broadcast code, which better had never been necessary in the first place. Reported-and-tested-by: Stehle Vincent-B46079 <B46079@freescale.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Cc: John Stultz <john.stultz@linaro.org>, Cc: Mark Rutland <mark.rutland@arm.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307012153060.4013@ionos.tec.linutronix.de Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* tick: Make oneshot broadcast robust vs. CPU offliningThomas Gleixner2013-07-021-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In periodic mode we remove offline cpus from the broadcast propagation mask. In oneshot mode we fail to do so. This was not a problem so far, but the recent changes to the broadcast propagation introduced a constellation which can result in a NULL pointer dereference. What happens is: CPU0 CPU1 idle() arch_idle() tick_broadcast_oneshot_control(OFF); set cpu1 in tick_broadcast_force_mask if (cpu_offline()) arch_cpu_dead() cpu_dead_cleanup(cpu1) cpu1 tickdevice pointer = NULL broadcast interrupt dereference cpu1 tickdevice pointer -> OOPS We dereference the pointer because cpu1 is still set in tick_broadcast_force_mask and tick_do_broadcast() expects a valid cpumask and therefor lacks any further checks. Remove the cpu from the tick_broadcast_force_mask before we set the tick device pointer to NULL. Also add a sanity check to the oneshot broadcast function, so we can detect such issues w/o crashing the machine. Reported-by: Prarit Bhargava <prarit@redhat.com> Cc: athorlton@sgi.com Cc: CAI Qian <caiqian@redhat.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1306261303260.4013@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: xen: Sync the CMOS RTC as well as the Xen wallclockDavid Vrabel2013-06-281-19/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adjustments to Xen's persistent clock via update_persistent_clock() don't actually persist, as the Xen wallclock is a software only clock and modifications to it do not modify the underlying CMOS RTC. The x86_platform.set_wallclock hook is there to keep the hardware RTC synchronized. On a guest this is pointless. On Dom0 we can use the native implementaion which actually updates the hardware RTC, but we still need to keep the software emulation of RTC for the guests up to date. The subscription to the pvclock_notifier allows us to emulate this easily. The notifier is called at every tick and when the clock was set. Right now we only use that notifier when the clock was set, but due to the fact that it is called periodically from the timekeeping update code, we can utilize it to emulate the NTP driven drift compensation of update_persistant_clock() for the Xen wall (software) clock. Add a 11 minutes periodic update to the pvclock_gtod notifier callback to achieve that. The static variable 'next' which maintains that 11 minutes update cycle is protected by the core code serialization so there is no need to add a Xen specific serialization mechanism. [ tglx: Massaged changelog and added a few comments ] Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1372329348-20841-6-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86: xen: Sync the wallclock when the system time is setDavid Vrabel2013-06-281-0/+28
| | | | | | | | | | | | | | | | | | | | | | | Currently the Xen wallclock is only updated every 11 minutes if NTP is synchronized to its clock source (using the sync_cmos_clock() work). If a guest is started before NTP is synchronized it may see an incorrect wallclock time. Use the pvclock_gtod notifier chain to receive a notification when the system time has changed and update the wallclock to match. This chain is called on every timer tick and we want to avoid an extra (expensive) hypercall on every tick. Because dom0 has historically never provided a very accurate wallclock and guests do not expect one, we can do this simply: the wallclock is only updated if the clock was set. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1372329348-20841-5-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* timekeeping: Indicate that clock was set in the pvclock gtod notifierDavid Vrabel2013-06-282-12/+25
| | | | | | | | | | | | | | | | | | If the clock was set (stepped), set the action parameter to functions in the pvclock gtod notifier chain to non-zero. This allows the callee to only do work if the clock was stepped. This will be used on Xen as the synchronization of the Xen wallclock to the control domain's (dom0) system time will be done with this notifier and updating on every timer tick is unnecessary and too expensive. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1372329348-20841-4-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* timekeeping: Pass flags instead of multiple bools to timekeeping_update()David Vrabel2013-06-281-9/+12
| | | | | | | | | | | | | Instead of passing multiple bools to timekeeping_updated(), define flags and use a single 'action' parameter. It is then more obvious what each timekeeping_update() call does. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1372329348-20841-3-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* xen: Remove clock_was_set() call in the resume pathDavid Vrabel2013-06-281-3/+0
| | | | | | | | | | | | | | | | | commit 359cdd3f866(xen: maintain clock offset over save/restore) added a clock_was_set() call into the xen resume code to propagate the system time changes. With the modified hrtimer resume code, which makes sure that all cpus are notified this call is not longer necessary. [ tglx: Separated it from the hrtimer change ] Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1372329348-20841-2-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimers: Support resuming with two or more CPUs online (but stopped)David Vrabel2013-06-281-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | hrtimers_resume() only reprograms the timers for the current CPU as it assumes that all other CPUs are offline at this point in the resume process. If other CPUs are online then their timers will not be corrected and they may fire at the wrong time. When running as a Xen guest, this assumption is not true. Non-boot CPUs are only stopped with IRQs disabled instead of offlining them. This is a performance optimization as disabling the CPUs would add an unacceptable amount of additional downtime during a live migration (> 200 ms for a 4 VCPU guest). hrtimers_resume() cannot call on_each_cpu(retrigger_next_event,...) as the other CPUs will be stopped with IRQs disabled. Instead, defer the call to the next softirq. [ tglx: Separated the xen change out ] Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/1372329348-20841-2-git-send-email-david.vrabel@citrix.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* timer: Fix jiffies wrap behavior of round_jiffies_common()Bart Van Assche2013-06-281-3/+5
| | | | | | | | | | | | Direct compare of jiffies related values does not work in the wrap around case. Replace it with time_is_after_jiffies(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/519BC066.5080600@acm.org Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: vf_pit_timer: Use linux/sched_clock.hFabio Estevam2013-06-251-1/+1
| | | | | | | | | | | | | | | Commit 38ff87f7 (sched_clock: Make ARM's sched_clock generic for all architectures) changed the header to <linux/sched_clock.h>, so adapt it in order to fix the following build error: drivers/clocksource/vf_pit_timer.c:15:29: fatal error: asm/sched_clock.h: No such file or directory Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: shawn.guo@linaro.org Cc: sboyd@codeaurora.org Cc: john.stultz@linaro.org Link: http://lkml.kernel.org/r/1372116008-2323-1-git-send-email-festevam@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'fortglx/3.11/time' of ↵Thomas Gleixner2013-06-251-0/+4
|\ | | | | | | git://git.linaro.org/people/jstultz/linux into timers/core
| * sched_clock: Add temporary asm/sched_clock.hStephen Boyd2013-06-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Some new users of the ARM sched_clock framework are going through the arm-soc tree. Before 38ff87f (sched_clock: Make ARM's sched_clock generic for all architectures, 2013-06-01) the header file was in asm, but now it's in linux. One solution would be to do an evil merge of the arm-soc tree and fix up the asm users, but it's easier to add a temporary asm header that we can remove along with the few stragglers after the merge window is over. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | clocksource: Add generic dummy timer driverMark Rutland2013-06-242-0/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | clockevents: Prefer CPU local devices over global devicesStephen Boyd2013-06-241-2/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On an SMP system with only one global clockevent and a dummy clockevent per CPU we run into problems. We want the dummy clockevents to be registered as the per CPU tick devices, but we can only achieve that if we register the dummy clockevents before the global clockevent or if we artificially inflate the rating of the dummy clockevents to be higher than the rating of the global clockevent. Failure to do so leads to boot hangs when the dummy timers are registered on all other CPUs besides the CPU that accepted the global clockevent as its tick device and there is no broadcast timer to poke the dummy devices. If we're registering multiple clockevents and one clockevent is global and the other is local to a particular CPU we should choose to use the local clockevent regardless of the rating of the device. This way, if the clockevent is a dummy it will take the tick device duty as long as there isn't a higher rated tick device and any global clockevent will be bumped out into broadcast mode, fixing the problem described above. Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: soren.brinkmann@xilinx.com Cc: John Stultz <john.stultz@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-arm-kernel@lists.infradead.org Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20130613183950.GA32061@codeaurora.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Revert "dw_apb_timer_of.c: Remove parts that were picoxcell-specific"John Stultz2013-06-194-29/+37
| | | | | | | | | | | | | | This reverts commit 55a68c23e0a675b2b8ac2656fd6edbf98b78e4c6. In order to avoid a collision with dw_apb_timer changes in the arm-soc tree, revert this change. I'm leaving it to the arm-soc folks to sort out if they want to keep the other side of the collision or if they're just going to back it all out and try again during the next release cycle. Reported-by: Dinh Nguyen <dinguyen@altera.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* ARM: sched_clock: Load cycle count after epoch stabilizesStephen Boyd2013-06-181-11/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a small race between when the cycle count is read from the hardware and when the epoch stabilizes. Consider this scenario: CPU0 CPU1 ---- ---- cyc = read_sched_clock() cyc_to_sched_clock() update_sched_clock() ... cd.epoch_cyc = cyc; epoch_cyc = cd.epoch_cyc; ... epoch_ns + cyc_to_ns((cyc - epoch_cyc) The cyc on cpu0 was read before the epoch changed. But we calculate the nanoseconds based on the new epoch by subtracting the new epoch from the old cycle count. Since epoch is most likely larger than the old cycle count we calculate a large number that will be converted to nanoseconds and added to epoch_ns, causing time to jump forward too much. Fix this problem by reading the hardware after the epoch has stabilized. Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* sched_clock: Make ARM's sched_clock generic for all architecturesStephen Boyd2013-06-1236-38/+45
| | | | | | | | | | Nothing about the sched_clock implementation in the ARM port is specific to the architecture. Generalize the code so that other architectures can use it by selecting GENERIC_SCHED_CLOCK. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> [jstultz: Merge minor collisions with other patches in my tree] Signed-off-by: John Stultz <john.stultz@linaro.org>
* ARM: sched_clock: Return suspended count earlierStephen Boyd2013-06-121-3/+3
| | | | | | | | | | | | If we're suspended and sched_clock() is called we're going to read the hardware one more time and throw away that value and return back the cached value we saved during the suspend callback. This is wasteful. Let's short circuit all that and return the cached value as early as possible if we're suspended. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* ARM: sched_clock: Remove unused needs_suspend memberStephen Boyd2013-06-121-1/+0
| | | | | | | | | | The needs_suspend member is unused now that we always do the suspend/resume handling (see 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during suspend, 2012-10-23)). Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Export symbols of functions declared in linux/alarmtimer.hMarcus Gelderie2013-06-121-1/+9
| | | | | | | | | | | Export symbols so they can be used by drivers/staging/android/alarm-dev.c if it is built as a module. So far alarm-dev is built-in but module support is planned (see drivers/staging/android/TODO). Signed-off-by: Marcus Gelderie <redmnic@gmail.com> [jstultz: tweaked commit message, also export newly added functions] Signed-off-by: John Stultz <john.stultz@linaro.org>
* Merge branch 'timers/clockevents' of ↵Thomas Gleixner2013-06-086-1/+450
|\ | | | | | | git://git.linaro.org/people/dlezcano/clockevents into timers/core
| * clocksource: Add TI-Nspire timer supportDaniel Tang2013-06-063-0/+249
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a clocksource/clockevent driver for the timer found on some models in the TI-Nspire calculator series. The timer has two 16bit subtimers within its memory mapped I/O interface but only the first can generate interrupts. The first subtimer is used to generate clockevents but only if an interrupt number and register is given. The interrupt acknowledgement mechanism is a little strange because the interrupt mask and acknowledge registers are located in another memory mapped I/O peripheral. The address of this register is passed to the driver through device tree bindings. The second subtimer is used as a clocksource because it isn't capable of generating an interrupt. This subtimer is always added. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Daniel Tang <dt.tangr@gmail.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| * clocksource: Add Freescale Vybrid pit timer supportJingchang Lu2013-06-063-0/+200
| | | | | | | | | | | | | | | | | | Add Freescale Vybrid Family period interrupt timer support. Signed-off-by: Jingchang Lu <b35083@freescale.com> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| * clocksource: dw_apb: Fix error checkBaruch Siach2013-06-061-1/+1
| | | | | | | | | | | | | | | | | | irq_of_parse_and_map() returns 0 on error, while the code checks for NO_IRQ. This breaks on platforms that have NO_IRQ != 0. Cc: <stable@vger.kernel.org> Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
* | x86: Fix vrtc_get_time/set_mmss to use new timespec interfaceJohn Stultz2013-05-292-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch "x86: Increase precision of x86_platform.get/set_wallclock" changed the x86 platform set_wallclock/get_wallclock interfaces to use nsec granular timespecs instead of a second granular interface. However, that patch missed converting the vrtc code, so this patch converts those functions to use timespecs. Many thanks to the kbuild test robot for finding this! Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | power: Add option to log time spent in suspendColin Cross2013-05-294-0/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Below is a patch from android kernel that maintains a histogram of suspend times. Please review and provide feedback. Statistices on the time spent in suspend are kept in /sys/kernel/debug/sleep_time. Cc: Android Kernel Team <kernel-team@android.com> Cc: Colin Cross <ccross@android.com> Cc: Todd Poynor <toddpoynor@google.com> Cc: San Mehat <san@google.com> Cc: Benoit Goby <benoit@android.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Todd Poynor <toddpoynor@google.com> [zoran.markovic@linaro.org: Re-formatted suspend time table to better fit expected values. Moved accounting of suspend time into timekeeping core. Removed CONFIG_SUSPEND_TIME flag and made the feature conditional on CONFIG_DEBUG_FS. Changed the file name to sleep_time to better fit terminology in timekeeping core. Changed seq_printf to seq_puts. Tweaked commit message] Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | timerfd: Add alarm timersTodd Poynor2013-05-291-23/+108
| | | | | | | | | | | | | | | | Add support for clocks CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM, thereby enabling wakeup alarm timers via file descriptors. Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | alarmtimer: Add functions for timerfd supportTodd Poynor2013-05-292-1/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add functions needed for hooking up alarmtimer to timerfd: * alarm_restart: Similar to hrtimer_restart, restart an alarmtimer after the expires time has already been updated (as with alarm_forward). * alarm_forward_now: Similar to hrtimer_forward_now, move the expires time forward to an interval from the current time of the associated clock. * alarm_start_relative: Start an alarmtimer with an expires time relative to the current time of the associated clock. * alarm_expires_remaining: Similar to hrtimer_expires_remaining, return the amount of time remaining until alarm expiry. Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | x86: Increase precision of x86_platform.get/set_wallclock()David Vrabel2013-05-288-41/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All the virtualized platforms (KVM, lguest and Xen) have persistent wallclocks that have more than one second of precision. read_persistent_wallclock() and update_persistent_wallclock() allow for nanosecond precision but their implementation on x86 with x86_platform.get/set_wallclock() only allows for one second precision. This means guests may see a wallclock time that is off by up to 1 second. Make set_wallclock() and get_wallclock() take a struct timespec parameter (which allows for nanosecond precision) so KVM and Xen guests may start with a more accurate wallclock time and a Xen dom0 can maintain a more accurate wallclock for guests. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | clocksource: dw_apb: Remove unused headerBaruch Siach2013-05-281-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The time.h header seems not to be used by current code. Removing this include allows the driver to build on other architecture that do not have this header. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jamie Iles <jamie@jamieiles.com> Cc: Dinh Nguyen <dinguyen@altera.com> Acked-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Baruch Siach <baruch@tkos.co.il> [tweaked commit message and header] Signed-off-by: John Stultz <john.stultz@linaro.org>
* | dw_apb_timer_of.c: Remove parts that were picoxcell-specificPavel Machek2013-05-284-37/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems we made a mistake when creating dw_apb_timer_of.c: picoxcell sched_clock had parts that were not related to dw_apb_timer, yet we moved them to dw_apb_timer_of, and tried to use them on socfpga. This results in system where user/system time is not measured properly, as demonstrated by time dd if=/dev/urandom of=/dev/zero bs=100000 count=100 So this patch switches sched_clock to hardware that exists on both platforms, and adds missing of_node_put() in dw_apb_timer_init(). Signed-off-by: Pavel Machek <pavel@denx.de> Acked-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | ktime: Add __must_check prefix to ktime_to_timespec_condDaniel Borkmann2013-05-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | The function is currently mainly used in the networking code and if others start using it, they must check the result, otherwise it cannot be determined if the timespec conversion suceeded. Currently no user lacks this check, but make future users aware of a possible misusage. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | ktime: Use macro NSEC_PER_USEC where appropriateLiu Ying2013-05-281-3/+4
|/ | | | | | | | | | | | | | | We've got the macro NSEC_PER_USEC defined in header file include/linux/time.h. To make the code decent, this patch replaces the immediate number 1000 to convert bewteen a time value in microseconds and one in nanoseconds with the macro NSEC_PER_USEC. Signed-off-by: Liu Ying <Ying.Liu@freescale.com> Cc: David S. Miller <davem@davemloft.net> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* clocksource: Implement clocksource_select_fallback() for ↵Thomas Gleixner2013-05-281-0/+1
| | | | | | | | | | | | | CONFIG_ARCH_USES_GETTIMEOFFSET=y commit 7eaeb34305 (clocksource: Provide unbind interface in sysfs) implemented clocksource_select_fallback() which is not defined for CONFIG_ARCH_USES_GETTIMEOFFSET=y. Add an empty inline function for that. Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: fengguang.wu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Define CS_NAME_LEN unconditionallyThomas Gleixner2013-05-281-2/+2
| | | | | | | | Unbreak architectures which do not use clockevents, but require to build some of the core timekeeping infrastructure Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Implement unbind functionalityThomas Gleixner2013-05-165-4/+162
| | | | | | | | | | | | | | | | Provide a sysfs interface to allow unbinding of clockevent devices. The device is unbound if it is unused or if there is a replacement device available. Unbinding of broadcast devices is not supported as we don't want to foster that nonsense. If no replacement device is available the unbind returns -EBUSY. Unbind is available from the kernel and through sysfs, which is necessary to drop the module refcount. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.499216659@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Split out selection logicThomas Gleixner2013-05-162-38/+56
| | | | | | | | | | | Split out the clockevent device selection logic. Preparatory patch to allow unbinding active clockevent devices. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.431796247@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Provide sysfs interfaceThomas Gleixner2013-05-161-0/+86
| | | | | | | | | | | Provide a simple sysfs interface for the clockevent devices. Show the current active clockevent device. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.371634778@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Add module refcountThomas Gleixner2013-05-164-0/+11
| | | | | | | | | | | | We want to be able to remove clockevent modules as well. Add a refcount so we don't remove a module with an active clock event device. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.307435149@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Move the tick_notify() switch case to clockevents_notify()Thomas Gleixner2013-05-163-48/+35
| | | | | | | | | | No need to call another function and have duplicated cases. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.235746557@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Simplify lockingThomas Gleixner2013-05-161-17/+5
| | | | | | | | | | | | Now that the notifier chain is gone there are no other users and it's pointless to nest tick_device_lock inside of clockevents_lock because there is no other use case. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.162888472@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clockevents: Get rid of the notifier chainThomas Gleixner2013-05-165-64/+14
| | | | | | | | | | 7+ years and still a single user. Kill it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.098520211@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Let clocksource_unregister() return success/errorThomas Gleixner2013-05-162-22/+13
| | | | | | | | | | | | | The unregister call can fail, if the clocksource is the current one and there is no replacement clocksource available. It can also fail, if the clocksource is the watchdog clocksource and I'm not going to provide support for this. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143436.029915527@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Provide unbind interface in sysfsThomas Gleixner2013-05-161-0/+73
| | | | | | | | | | | | | | | | | | | | | | | | | With the module refcount held for the current clocksource there is no way to unload the module. Provide a sysfs interface which allows to unbind the clocksource. One could argue that the clocksource override could be (ab)used to do so, but the clocksource override cannot be used from the kernel itself, while an unbind function can be used to programmatically check whether a clocksource can be shutdown or not. The unbind functionality uses the new skip current feature of clocksource_select and verifies that a fallback clocksource has been installed. If the clocksource which should be unbound is the current clocksource and no fallback can be found, unbind returns -EBUSY. This does not support the unbinding of a clocksource which is used as the watchdog clocksource. No point in fostering crappy hardware. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143435.964218245@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Split out user string inputThomas Gleixner2013-05-161-14/+23
| | | | | | | | | | | | | Split out the user string input for clocksource override. Preparatory patch for unbind. [ jstultz: Fix an off by one error ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143435.895851338@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Allow clocksource select to skip current clocksourceThomas Gleixner2013-05-161-11/+20
| | | | | | | | | | | | | | Preparatory patch for clocksource unbind support. Split out code from clocksource_select and modify it, so it skips the current clocksource on request and tries to find a fallback clocksource. Convert all existing users. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143435.834965397@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Add module refcountThomas Gleixner2013-05-162-5/+17
| | | | | | | | | | | Add a module refcount, so the current clocksource cannot be removed unconditionally. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143435.762417789@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Let timekeeping_notify return success/errorThomas Gleixner2013-05-163-6/+7
| | | | | | | | | | | | | | | timekeeping_notify() can fail due cs->enable() failure. Though the caller does not notice and happily keeps the wrong clocksource as the current one. Let the caller know about failure, so the current clocksource will be shown correctly in sysfs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143435.696321912@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* clocksource: Always verify highres capabilityThomas Gleixner2013-05-161-5/+26
| | | | | | | | | | | | | | | If a clocksource has a (wrong) high rating, but can't be used as a timebase for oneshot tick mode, it is unconditionally selected even when the system is already in oneshot tick mode. This causes full system failure. Verify the clocksource selection against the oneshot mode. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Magnus Damm <magnus.damm@gmail.com> Link: http://lkml.kernel.org/r/20130425143435.635040849@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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