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path: root/include/linux/clocksource.h
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2015-11-25timekeeping: Lift clocksource cacheline restrictionThomas Gleixner
We cache all hotpath members of a clocksource in the time keeper core. So there is no requirement in general to cache line align struct clocksource. Remove the enforces alignment. That allows users which need to wrap struct clocksource into their own struct to align the struct without getting extra padding. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mans Rullgard <mans@mansr.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Tony Lindgren <tony@atomide.com> Cc: Sebastian Frias <sebastian_frias@sigmadesigns.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1511191209000.3898@nanos
2015-10-01clocksource: cosmetic: Drop OF 'dependency' from symbolsMarc Zyngier
Seeing the 'of' characters in a symbol that is being called from ACPI seems to freak out people. So let's do a bit of pointless renaming so that these folks do feel at home. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01clocksource / arm_arch_timer: Convert to ACPI probingMarc Zyngier
It is now absolutely trivial to convert the arch timer driver to use ACPI probing, just like its DT counterpart. Let's enjoy another crapectomy. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01clocksource: Add new CLKSRC_{PROBE,ACPI} config symbolsMarc Zyngier
The clocksource probing infrastructure currently depends on CONFIG_CLKSRC_OF, which depends on CONFIG_OF. In order to make this infrastructure selectable even if CONFIG_OF is not selected, introduce a new CONFIG_CLKSRC_PROBE (which allow the infrastructure to be compiled in), and CONFIG_CLKSRC_ACPI (which is the pendent of CONFIG_CLKSRC_OF for ACPI). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-01clocksource / ACPI: Add probing infrastructure for ACPI-based clocksourcesMarc Zyngier
DT enjoys a rather nice probing infrastructure for clocksources, while ACPI is so far stuck into a very distant past. This patch introduces a declarative API, allowing clocksources to be self-contained and be called when parsing the GTDT table. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-19Merge branch 'linus' into timers/coreThomas Gleixner
Make sure the upstream fixes are applied before adding further modifications.
2015-04-24Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull initial ACPI support for arm64 from Will Deacon: "This series introduces preliminary ACPI 5.1 support to the arm64 kernel using the "hardware reduced" profile. We don't support any peripherals yet, so it's fairly limited in scope: - MEMORY init (UEFI) - ACPI discovery (RSDP via UEFI) - CPU init (FADT) - GIC init (MADT) - SMP boot (MADT + PSCI) - ACPI Kconfig options (dependent on EXPERT) ACPI for arm64 has been in development for a while now and hardware has been available that can boot with either FDT or ACPI tables. This has been made possible by both changes to the ACPI spec to cater for ARM-based machines (known as "hardware-reduced" in ACPI parlance) but also a Linaro-driven effort to get this supported on top of the Linux kernel. This pull request is the result of that work. These changes allow us to initialise the CPUs, interrupt controller, and timers via ACPI tables, with memory information and cmdline coming from EFI. We don't support a hybrid ACPI/FDT scheme. Of course, there is still plenty of work to do (a serial console would be nice!) but I expect that to happen on a per-driver basis after this core series has been merged. Anyway, the diff stat here is fairly horrible, but splitting this up and merging it via all the different subsystems would have been extremely painful. Instead, we've got all the relevant Acks in place and I've not seen anything other than trivial (Kconfig) conflicts in -next (for completeness, I've included my resolution below). Nearly half of the insertions fall under Documentation/. So, we'll see how this goes. Right now, it all depends on EXPERT and I fully expect people to use FDT by default for the immediate future" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits) ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface() ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface ARM64: kernel: acpi: honour acpi=force command line parameter ARM64: kernel: acpi: refactor ACPI tables init and checks ARM64: kernel: psci: let ACPI probe PSCI version ARM64: kernel: psci: factor out probe function ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed ARM64 / ACPI: additions of ACPI documentation for arm64 Documentation: ACPI for ARM64 ARM64 / ACPI: Enable ARM64 in Kconfig XEN / ACPI: Make XEN ACPI depend on X86 ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64 clocksource / arch_timer: Parse GTDT to initialize arch timer irqchip: Add GICv2 specific ACPI boot support ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi ACPI / processor: Make it possible to get CPU hardware ID via GICC ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID ARM64 / ACPI: Parse MADT for SMP initialization ...
2015-04-22time: Remove nonexistent function prototypeYingjoe Chen
The function clocksource_get_next() was removed in commit 75c5158f70 (timekeeping: Update clocksource with stop_machine), but the prototype was not removed with it. Remove the prototype. Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com> Cc: <linux-arm-kernel@lists.infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <srv_heupstream@mediatek.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/1428674150-1780-1-git-send-email-yingjoe.chen@mediatek.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-03-26clocksource / arch_timer: Parse GTDT to initialize arch timerHanjun Guo
Using the information presented by GTDT (Generic Timer Description Table) to initialize the arch timer (not memory-mapped). CC: Daniel Lezcano <daniel.lezcano@linaro.org> CC: Thomas Gleixner <tglx@linutronix.de> Originally-by: Amit Daniel Kachhap <amit.daniel@samsung.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-13clocksource: Rename __clocksource_updatefreq_*() to ↵John Stultz
__clocksource_update_freq_*() Ingo requested this function be renamed to improve readability, so I've renamed __clocksource_updatefreq_scale() as well as the __clocksource_updatefreq_hz/khz() functions to avoid squishedtogethernames. This touches some of the sh clocksources, which I've not tested. The arch/arm/plat-omap change is just a comment change for consistency. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1426133800-29329-13-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-13clocksource: Mostly kill clocksource_register()John Stultz
A long running project has been to clean up remaining uses of clocksource_register(), replacing it with the simpler clocksource_register_khz/hz() functions. However, there are a few cases where we need to self-define our mult/shift values, so switch the function to a more obviously internal __clocksource_register() name, and consolidate much of the internal logic so we don't have duplication. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1426133800-29329-10-git-send-email-john.stultz@linaro.org [ Minor cleanups. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-12clocksource: Add 'max_cycles' to 'struct clocksource'John Stultz
In order to facilitate clocksource validation, add a 'max_cycles' field to the clocksource structure which will hold the maximum cycle value that can safely be multiplied without potentially causing an overflow. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1426133800-29329-4-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-12-30time: move the timecounter/cyclecounter code into its own file.Richard Cochran
The timecounter code has almost nothing to do with the clocksource code. Let it live in its own file. This will help isolate the timecounter users from the clocksource users in the source tree. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-22clocksource: Remove "weak" from clocksource_default_clock() declarationBjorn Helgaas
kernel/time/jiffies.c provides a default clocksource_default_clock() definition explicitly marked "weak". arch/s390 provides its own definition intended to override the default, but the "weak" attribute on the declaration applied to the s390 definition as well, so the linker chose one based on link order (see 10629d711ed7 ("PCI: Remove __weak annotation from pcibios_get_phb_of_node decl")). Remove the "weak" attribute from the clocksource_default_clock() declaration so we always prefer a non-weak definition over the weak one, independent of link order. Fixes: f1b82746c1e9 ("clocksource: Cleanup clocksource selection") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Ingo Molnar <mingo@kernel.org> CC: Daniel Lezcano <daniel.lezcano@linaro.org> CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-07-23clocksource: Get rid of cycle_lastThomas Gleixner
cycle_last was added to the clocksource to support the TSC validation. We moved that to the core code, so we can get rid of the extra copy. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-05-20of: consolidate linker section OF match table declarationsRob Herring
We now have several OF match tables using linker sections that are nearly the same definition. The only variation is the callback function prototype. Create a common define for creating linker section OF match table entries which each table declaration can use. Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rob Herring <robh@kernel.org>
2013-07-30clocksource: Extract max nsec calculation into separate functionStephen Boyd
We need to calculate the same number in the clocksource code and the sched_clock code, so extract this code into its own function. We also drop the min_t and just use min() because the two types are the same. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-07-05clocksource: Reselect clocksource when watchdog validated high-res capabilityThomas Gleixner
Up to commit 5d33b883a (clocksource: Always verify highres capability) we had no sanity check when selecting a clocksource, which prevented that a non highres capable clocksource is used when the system already switched to highres/nohz mode. The new sanity check works as Alex and Tim found out. It prevents the TSC from being used. This happens because on x86 the boot process looks like this: tsc_start_freqency_validation(TSC); clocksource_register(HPET); clocksource_done_booting(); clocksource_select() Selects HPET which is valid for high-res switch_to_highres(); clocksource_register(TSC); TSC is not selected, because it is not yet flagged as VALID_HIGH_RES clocksource_watchdog() Validates TSC for highres, but that does not make TSC the current clocksource. Before the sanity check was added, we installed TSC unvalidated which worked most of the time. If the TSC was really detected as unstable, then the unstable logic removed it and installed HPET again. The sanity check is correct and needed. So the watchdog needs to kick a reselection of the clocksource, when it qualifies TSC as a valid high res clocksource. To solve this, we mark the clocksource which got the flag CLOCK_SOURCE_VALID_FOR_HRES set by the watchdog with an new flag CLOCK_SOURCE_RESELECT and trigger the watchdog thread. The watchdog thread evaluates the flag and invokes clocksource_select() when set. To avoid that the clocksource_done_booting() code, which is about to install the first real clocksource anyway, needs to go through clocksource_select and tick_oneshot_notify() pointlessly, split out the clocksource_watchdog_kthread() list walk code and invoke the select/notify only when called from clocksource_watchdog_kthread(). So clocksource_done_booting() can utilize the same splitout code without the select/notify invocation and the clocksource_mutex unlock/relock dance. Reported-and-tested-by: Alex Shi <alex.shi@intel.com> Cc: Hans Peter Anvin <hpa@linux.intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@kernel.org> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307042239150.11637@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-05-16clocksource: Let clocksource_unregister() return success/errorThomas Gleixner
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>
2013-05-16clocksource: Add module refcountThomas Gleixner
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>
2013-05-16clocksource: Let timekeeping_notify return success/errorThomas Gleixner
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>
2013-05-02Merge tag 'cleanup-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC cleanup from Olof Johansson: "Here is a collection of cleanup patches. Among the pieces that stand out are: - The deletion of h720x platforms - Split of at91 non-dt platforms to their own Kconfig file to keep them separate - General cleanups and refactoring of i.MX and MXS platforms - Some restructuring of clock tables for OMAP - Convertion of PMC driver for Tegra to dt-only - Some renames of sunxi -> sun4i (Allwinner A10) - ... plus a bunch of other stuff that I haven't mentioned" * tag 'cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (119 commits) ARM: i.MX: remove unused ARCH_* configs ARM i.MX53: remove platform ahci support ARM: sunxi: Rework the restart code irqchip: sunxi: Rename sunxi to sun4i irqchip: sunxi: Make use of the IRQCHIP_DECLARE macro clocksource: sunxi: Rename sunxi to sun4i clocksource: sunxi: make use of CLKSRC_OF clocksource: sunxi: Cleanup the timer code ARM: at91: remove trailing semicolon from macros ARM: at91/setup: fix trivial typos ARM: EXYNOS: remove "config EXYNOS_DEV_DRM" ARM: EXYNOS: change the name of USB ohci header ARM: SAMSUNG: Remove unnecessary code for dma ARM: S3C24XX: Remove unused GPIO drive strength register definitions ARM: OMAP4+: PM: Restore CPU power state to ON with clockdomain force wakeup method ARM: S3C24XX: Removed unneeded dependency on CPU_S3C2412 ARM: S3C24XX: Removed unneeded dependency on CPU_S3C2410 ARM: S3C24XX: Removed unneeded dependency on ARCH_S3C24XX for boards ARM: SAMSUNG: Fix typo "CONFIG_SAMSUNG_DEV_RTC" ARM: S5P64X0: Fix typo "CONFIG_S5P64X0_SETUP_SDHCI" ...
2013-03-28clocksource: make CLOCKSOURCE_OF_DECLARE type safeArnd Bergmann
This ensures that a function pointer passed into CLOCKSOURCE_OF_DECLARE takes the same arguments that we use for calling that function later. Also fix the extraneous semicolon at end of the CLOCKSOURCE_OF_DECLARE definition. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Rob Herring <rob.herring@calxeda.com>
2013-03-15clocksource: Add new feature flag CLOCK_SOURCE_SUSPEND_NONSTOPFeng Tang
Some x86 processors have a TSC clocksource, which continues to run even when system is suspended. Also most OMAP platforms have a 32 KHz timer which has similar capability. Add a feature flag so that it could be utilized. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-03-11clocksource: add empty version of clocksource_of_initRob Herring
Add an empty clocksource_of_init when !CLKSRC_OF. This is needed for builds where no timer has selected CLKSRC_OF. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2013-01-31clocksource: always define CLOCKSOURCE_OF_DECLAREStephen Warren
This allows clocksource drivers that support both DT and non-DT to always invoke macro CLOCKSOURCE_OF_DECLARE(), rather than wrapping it in a #ifdef CONFIG_CLKSRC_OF, which simplifies their code. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-02clocksource: add common of_clksrc_init() functionStephen Warren
It is desirable to move all clocksource drivers to drivers/clocksource, yet each requires its own initialization function. We'd rather not pollute <linux/> with a header for each function. Instead, create a single of_clksrc_init() function which will determine which clocksource driver to initialize based on device tree. Based on a similar patch for drivers/irqchip by Thomas Petazzoni. Signed-off-by: Stephen Warren <swarren@nvidia.com>
2012-09-24time: Move update_vsyscall definitions to timekeeper_internal.hJohn Stultz
Since users will need to include timekeeper_internal.h, move update_vsyscall definitions to timekeeper_internal.h. Cc: Tony Luck <tony.luck@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-02-01clocksource: Get rid of clocksource_calc_mult_shift()Yong Zhang
No one is using this, so encourage the use of clocksource_register_hz/khz(), and drop this helper. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> [jstultz: tweaked commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-12-19time/clocksource: Fix kernel-doc warningsKusanagi Kouichi
Fix various KernelDoc build warnings. Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Cc: John Stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20111219091320.0D5AF6FC03D@msa105.auone-net.jp Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-11-10clocksource: Avoid selecting mult values that might overflow when adjustedJohn Stultz
For some frequencies, the clocks_calc_mult_shift() function will unfortunately select mult values very close to 0xffffffff. This has the potential to overflow when NTP adjusts the clock, adding to the mult value. This patch adds a clocksource.maxadj value, which provides an approximation of an 11% adjustment(NTP limits adjustments to 500ppm and the tick adjustment is limited to 10%), which could be made to the clocksource.mult value. This is then used to both check that the current mult value won't overflow/underflow, as well as warning us if the timekeeping_adjust() code pushes over that 11% boundary. v2: Fix max_adjustment calculation, and improve WARN_ONCE messages. v3: Don't warn before maxadj has actually been set CC: Yong Zhang <yong.zhang0@gmail.com> CC: David Daney <ddaney.cavm@gmail.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Chen Jie <chenj@lemote.com> CC: zhangfx <zhangfx@lemote.com> CC: stable@kernel.org Reported-by: Chen Jie <chenj@lemote.com> Reported-by: zhangfx <zhangfx@lemote.com> Tested-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-07-22Merge branch 'x86-vdso-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86-64, vdso: Do not allocate memory for the vDSO clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option x86, vdso: Drop now wrong comment Document the vDSO and add a reference parser ia64: Replace clocksource.fsys_mmio with generic arch data x86-64: Move vread_tsc and vread_hpet into the vDSO clocksource: Replace vread with generic arch data x86-64: Add --no-undefined to vDSO build x86-64: Allow alternative patching in the vDSO x86: Make alternative instruction pointers relative x86-64: Improve vsyscall emulation CS and RIP handling x86-64: Emulate legacy vsyscalls x86-64: Fill unused parts of the vsyscall page with 0xcc x86-64: Remove vsyscall number 3 (venosys) x86-64: Map the HPET NX x86-64: Remove kernel.vsyscall64 sysctl x86-64: Give vvars their own page x86-64: Document some of entry_64.S x86-64: Fix alignment of jiffies variable
2011-07-21clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG optionH. Peter Anvin
The machinery for __ARCH_HAS_CLOCKSOURCE_DATA assumed a file in asm-generic would be the default for architectures without their own file in asm/, but that is not how it works. Replace it with a Kconfig option instead. Link: http://lkml.kernel.org/r/4E288AA6.7090804@zytor.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Tony Luck <tony.luck@intel.com>
2011-07-14ia64: Replace clocksource.fsys_mmio with generic arch dataAndy Lutomirski
Now that clocksource.archdata is available, use it for ia64-specific code. Cc: Clemens Ladisch <clemens@ladisch.de> Cc: linux-ia64@vger.kernel.org Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/d31de0ee0842a0e322fb6441571c2b0adb323fa2.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-13clocksource: Replace vread with generic arch dataAndy Lutomirski
The vread field was bloating struct clocksource everywhere except x86_64, and I want to change the way this works on x86_64, so let's split it out into per-arch data. Cc: x86@kernel.org Cc: Clemens Ladisch <clemens@ladisch.de> Cc: linux-ia64@vger.kernel.org Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/3ae5ec76a168eaaae63f08a2a1060b91aa0b7759.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-16clocksource: Make watchdog robust vs. interruptionThomas Gleixner
The clocksource watchdog code is interruptible and it has been observed that this can trigger false positives which disable the TSC. The reason is that an interrupt storm or a long running interrupt handler between the read of the watchdog source and the read of the TSC brings the two far enough apart that the delta is larger than the unstable treshold. Move both reads into a short interrupt disabled region to avoid that. Reported-and-tested-by: Vernon Mauery <vernux@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2011-05-23clocksource: add common mmio clocksourceRussell King
Add a generic mmio clocksource, covering both 32-bit and 16-bit register access sizes, for up or down counters. This can be used to easily create clocksources for simple counter-based implementations. Cc: Alessandro Rubini <rubini@unipv.it> Cc: Colin Cross <ccross@android.com> Cc: Eric Miao <eric.y.miao@gmail.com> Cc: Erik Gilling <konkers@android.com> Acked-by: "Hans J. Koch" <hjk@hansjkoch.de> Cc: Imre Kaloz <kaloz@openwrt.org> Cc: Krzysztof Halasa <khc@pm.waw.pl> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Lennert Buytenhek <kernel@wantstofly.org> Cc: Linus Walleij <linus.walleij@stericsson.com> Cc: linux-omap@vger.kernel.org Acked-by: Nicolas Pitre <nico@fluxnic.net> Cc: Olof Johansson <olof@lixom.net> Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Viresh Kumar <viresh.kumar@st.com> Cc: Wan ZongShun <mcuos.com@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-19clocksource: Restructure clocksource struct membersThomas Gleixner
Group the hot path members of struct clocksource together so we have a better cache line footprint. Make it cacheline aligned. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Link: http://lkml.kernel.org/r/%3C20110518210136.003081882%40linutronix.de%3E
2011-05-14Merge branch 'consolidate-clksrc-i8253' of ↵Thomas Gleixner
master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource Conflicts: arch/ia64/kernel/cyclone.c arch/mips/kernel/i8253.c arch/x86/kernel/i8253.c Reason: Resolve conflicts so further cleanups do not conflict further Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-14clocksource: convert footbridge to generic i8253 clocksourceRussell King
Convert the footbridge isa-timer code to use generic i8253 clocksource. Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-21Make clocksource name constRussell King - ARM Linux
As nothing should be writing to the clocksource name string, make the clocksource name pointer const. Build-tested on ARM Versatile Express. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: John Stultz <johnstul@us.ibm.com>
2010-07-27clocksource: Add __clocksource_updatefreq_hz/khz methodsJohn Stultz
To properly handle clocksources that change frequencies at the clocksource->enable() point, this patch adds a method that will update the clocksource's mult/shift and max_idle_ns values. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-12-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-27timkeeping: Fix update_vsyscall to provide wall_to_monotonic offsetJohn Stultz
update_vsyscall() did not provide the wall_to_monotoinc offset, so arch specific implementations tend to reference wall_to_monotonic directly. This limits future cleanups in the timekeeping core, so this patch fixes the update_vsyscall interface to provide wall_to_monotonic, allowing wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Tony Luck <tony.luck@intel.com> LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-05-10clocksource: Add clocksource_register_hz/khz interfaceJohn Stultz
How to pick good mult/shift pairs has always been difficult to describe to folks writing clocksource drivers, since it requires careful tradeoffs in adjustment accuracy vs overflow limits. Now, with the clocks_calc_mult_shift function, its much easier. However, not many clocksources have converted to using that function, and there is still the issue of the max interval length assumption being made by each clocksource driver independently. So this patch simplifies the registration process by having clocksources be registered with a hz/khz value and the registration function taking care of setting mult/shift. This should take most of the confusion out of writing a clocksource driver. Additionally it also keeps the shift size tradeoff (more accuracy vs longer possible nohz times) centralized so the timekeeping core can keep track of the assumptions being made. [ tglx: Coding style and comments fixed ] Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1273280858-30143-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-05clocksource: add suspend callbackMagnus Damm
Add a clocksource suspend callback. This callback can be used by the clocksource driver to shutdown and perform any kind of late suspend activities even though the clocksource driver itself is a non-sysdev driver. One example where this is useful is to fix the sh_cmt.c platform driver that today suspends using the platform bus and shuts down the clocksource too early. With this callback in place the sh_cmt driver will suspend using the clocksource and clockevent hooks and leave the platform device pm callbacks unused. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-02-05clocksource: add argument to resume callbackMagnus Damm
Pass the clocksource as an argument to the clocksource resume callback. Needed so we can point out which CMT channel the sh_cmt.c driver shall resume. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: john stultz <johnstul@us.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-08Merge branch 'timers-for-linus-urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: hrtimer: Fix /proc/timer_list regression itimers: Fix racy writes to cpu_itimer fields timekeeping: Fix clock_gettime vsyscall time warp
2009-11-17timekeeping: Fix clock_gettime vsyscall time warpLin Ming
Since commit 0a544198 "timekeeping: Move NTP adjusted clock multiplier to struct timekeeper" the clock multiplier of vsyscall is updated with the unmodified clock multiplier of the clock source and not with the NTP adjusted multiplier of the timekeeper. This causes user space observerable time warps: new CLOCK-warp maximum: 120 nsecs, 00000025c337c537 -> 00000025c337c4bf Add a new argument "mult" to update_vsyscall() and hand in the timekeeping internal NTP adjusted multiplier. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Cc: "Zhang Yanmin" <yanmin_zhang@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> LKML-Reference: <1258436990.17765.83.camel@minggr.sh.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-11-13nohz: Prevent clocksource wrapping during idleJon Hunter
The dynamic tick allows the kernel to sleep for periods longer than a single tick, but it does not limit the sleep time currently. In the worst case the kernel could sleep longer than the wrap around time of the time keeping clock source which would result in losing track of time. Prevent this by limiting it to the safe maximum sleep time of the current time keeping clock source. The value is calculated when the clock source is registered. [ tglx: simplified the code a bit and massaged the commit msg ] Signed-off-by: Jon Hunter <jon-hunter@ti.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1250617512-23567-2-git-send-email-jon-hunter@ti.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-11-13clocksource: Provide a generic mult/shift factor calculationThomas Gleixner
MIPS has two functions to calculcate the mult/shift factors for clock sources and clock events at run time. ARM needs such functions as well. Implement a function which calculates the mult/shift factors based on the frequencies to which and from which is converted. The function also has a parameter to specify the minimum conversion range in seconds. This range is guaranteed not to produce a 64bit overflow when a value is multiplied with the calculated mult factor. The larger the conversion range the less becomes the conversion accuracy. Provide two inline wrappers which handle clock events and clock sources. For clock events the "from" frequency is nano seconds per second which corresponds to 1GHz and "to" is the device frequency. For clock sources "from" is the device frequency and "to" is nano seconds per second. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20091111134229.766673305@linutronix.de>