- 27 Mar, 2015 13 commits
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Viresh Kumar authored
'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 <peterz@infradead.org> Suggested-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
Viresh Kumar <viresh.kumar@linaro.org> Acked-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> 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.orgSigned-off-by:
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Viresh Kumar authored
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:
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Peter Zijlstra authored
Because it was the only clock for which we didn't have a _ns() accessor yet. Signed-off-by:
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Peter Zijlstra authored
Add the NMI safe CLOCK_MONOTONIC_RAW accessor.. Signed-off-by:
John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.562746929@infradead.orgSigned-off-by:
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Peter Zijlstra authored
In preparation for more tk_fast instances, remove all hard-coded tk_fast_mono references. Signed-off-by:
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Peter Zijlstra authored
Introduce tkr_raw and make use of it. base_raw -> tkr_raw.base clock->{mult,shift} -> tkr_raw.{mult.shift} Kill timekeeping_get_ns_raw() in favour of timekeeping_get_ns(&tkr_raw), this removes all mono_raw special casing. Duplicate the updates to tkr_mono.cycle_last into tkr_raw.cycle_last, both need the same value. Signed-off-by: -
Peter Zijlstra authored
In preparation of adding another tkr field, rename this one to tkr_mono. Also rename tk_read_base::base_mono to tk_read_base::base, since the structure is not specific to CLOCK_MONOTONIC and the mono name got added to the tk_read_base instance. Lots of trivial churn. Signed-off-by:
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Ingo Molnar authored
Trivial cleanups, to improve the readability of the generic sched_clock() code: - Improve and standardize comments - Standardize the coding style - Use vertical spacing where appropriate - etc. No code changed: md5: 19a053b31e0c54feaeff1492012b019a sched_clock.o.before.asm 19a053b31e0c54feaeff1492012b019a sched_clock.o.after.asm Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: -
Daniel Thompson authored
Currently it is possible for an NMI (or FIQ on ARM) to come in and read sched_clock() whilst update_sched_clock() has locked the seqcount for writing. This results in the NMI handler locking up when it calls raw_read_seqcount_begin(). This patch fixes the NMI safety issues by providing banked clock data. This is a similar approach to the one used in Thomas Gleixner's 4396e058("timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC"). Suggested-by:
Stephen Boyd <sboyd@codeaurora.org> Signed-off-by:
Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by:
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Daniel Thompson authored
Currently update_sched_clock() is marked as notrace but this function is not called by ftrace. This is trivially fixed by removing the mark up. Signed-off-by:
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Daniel Thompson authored
Currently cd.read_data.suspended is read by the hotpath function sched_clock(). This variable need not be accessed on the hotpath. In fact, once it is removed, we can remove the conditional branches from sched_clock() and install a dummy read_sched_clock function to suspend the clock. The new master copy of the function pointer (actual_read_sched_clock) is introduced and is used for all reads of the clock hardware except those within sched_clock itself. Suggested-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Daniel Thompson authored
Currently sched_clock(), a very hot code path, is not optimized to minimise its cache profile. In particular: 1. cd is not ____cacheline_aligned, 2. struct clock_data does not distinguish between hotpath and coldpath data, reducing locality of reference in the hotpath, 3. Some hotpath data is missing from struct clock_data and is marked __read_mostly (which more or less guarantees it will not share a cache line with cd). This patch corrects these problems by extracting all hotpath data into a separate structure and using ____cacheline_aligned to ensure the hotpath uses a single (64 byte) cache line. Signed-off-by: -
Daniel Thompson authored
Currently the scope of the raw_write_seqcount_begin/end() in sched_clock_register() far exceeds the scope of the read section in sched_clock(). This gives the impression of safety during cursory review but achieves little. Note that this is likely to be a latent issue at present because sched_clock_register() is typically called before we enable interrupts, however the issue does risk bugs being needlessly introduced as the code evolves. This patch fixes the problem by increasing the scope of the read locking performed by sched_clock() to cover all data modified by sched_clock_register. We also improve clarity by moving writes to struct clock_data that do not impact sched_clock() outside of the critical section. Signed-off-by:
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- 17 Mar, 2015 1 commit
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Ingo Molnar authored
Signed-off-by:
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- 13 Mar, 2015 9 commits
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John Stultz authored
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:
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John Stultz authored
Print the mask, max_cycles, and max_idle_ns values for clocksources being registered. Signed-off-by:
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John Stultz authored
While cleaning up some clocksource code, I noticed the time_32 implementation uses the clocksource_hz2mult() helper, but doesn't use the clocksource_register_hz() method. I don't believe the Sparc clocksource is a default clocksource, so we shouldn't need to self-define the mult/shift pair. So convert the time_32.c implementation to use clocksource_register_hz(). Untested. Signed-off-by:
David S. Miller <davem@davemloft.net> 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/1426133800-29329-11-git-send-email-john.stultz@linaro.orgSigned-off-by:
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John Stultz authored
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:
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John Stultz authored
The clocksource watchdog reporting has been less helpful then desired, as it just printed the delta between the two clocksources. This prevents any useful analysis of why the skew occurred. Thus this patch tries to improve the output when we mark a clocksource as unstable, printing out the cycle last and now values for both the current clocksource and the watchdog clocksource. This will allow us to see if the result was due to a false positive caused by a problematic watchdog. Signed-off-by:
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John Stultz authored
It was suggested that the underflow/overflow protection should probably throw some sort of warning out, rather than just silently fixing the issue. So this patch adds some warnings here. The flag variables used are not protected by locks, but since we can't print from the reading functions, just being able to say we saw an issue in the update interval is useful enough, and can be slightly racy without real consequence. The big complication is that we're only under a read seqlock, so the data could shift under us during our calculation to see if there was a problem. This patch avoids this issue by nesting another seqlock which allows us to snapshot the just required values atomically. So we shouldn't see false positives. I also added some basic rate-limiting here, since on one build machine w/ skewed TSCs it was fairly noisy at bootup. Signed-off-by:
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John Stultz authored
In the case where there is a broken clocksource where there are multiple actual clocks that aren't perfectly aligned, we may see small "negative" deltas when we subtract 'now' from 'cycle_last'. The values are actually negative with respect to the clocksource mask value, not necessarily negative if cast to a s64, but we can check by checking the delta to see if it is a small (relative to the mask) negative value (again negative relative to the mask). If so, we assume we jumped backwards somehow and instead use zero for our delta. Signed-off-by:
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John Stultz authored
When calculating the current delta since the last tick, we currently have no hard protections to prevent a multiplication overflow from occuring. This patch introduces infrastructure to allow a cap that limits the clocksource read delta value to the 'max_cycles' value, which is where an overflow would occur. Since this is in the hotpath, it adds the extra checking under CONFIG_DEBUG_TIMEKEEPING=y. There was some concern that capping time like this could cause problems as we may stop expiring timers, which could go circular if the timer that triggers time accumulation were mis-scheduled too far in the future, which would cause time to stop. However, since the mult overflow would result in a smaller time value, we would effectively have the same problem there. Signed-off-by:
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John Stultz authored
Recently there's been requests for better sanity checking in the time code, so that it's more clear when something is going wrong, since timekeeping issues could manifest in a large number of strange ways in various subsystems. Thus, this patch adds some extra infrastructure to add a check to update_wall_time() to print two new warnings: 1) if we see the call delayed beyond the 'max_cycles' overflow point, 2) or if we see the call delayed beyond the clocksource's 'max_idle_ns' value, which is currently 50% of the overflow point. This extra infrastructure is conditional on a new CONFIG_DEBUG_TIMEKEEPING option, also added in this patch - default off. Tested this a bit by halting qemu for specified lengths of time to trigger the warnings. Signed-off-by:
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- 12 Mar, 2015 3 commits
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John Stultz authored
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:
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John Stultz authored
The clocksource logic has a number of places where we try to include a safety margin. Most of these are 12% safety margins, but they are inconsistently applied and sometimes are applied on top of each other. Additionally, in the previous patch, we corrected an issue where we unintentionally in effect created a 50% safety margin, which these 12.5% margins where then added to. So to simplify the logic here, this patch removes the various 12.5% margins, and consolidates adding the margin in one place: clocks_calc_max_nsecs(). Additionally, Linus prefers a 50% safety margin, as it allows bad clock values to be more easily caught. This should really have no net effect, due to the corrected issue earlier which caused greater then 50% margins to be used w/o issue. Signed-off-by:
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John Stultz authored
The previous clocks_calc_max_nsecs() code had some unecessarily complex bit logic to find the max interval that could cause multiplication overflows. Since this is not in the hot path, just do the divide to make it easier to read. The previous implementation also had a subtle issue that it avoided overflows with signed 64-bit values, where as the intervals are always unsigned. This resulted in overly conservative intervals, which other safety margins were then added to, reducing the intended interval length. Signed-off-by:
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- 05 Mar, 2015 3 commits
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Ingo Molnar authored
Merge branch 'clockevents/4.0-rc2' of http://git.linaro.org/people/daniel.lezcano/linux into timers/urgent Pull clockevents fixes from Daniel Lezcano: " These two patches fix a potential crash at boot time. - Fix setup_irq / clockevents_config_and_register init ordering in order to prevent to have an interrupt to be fired before the handler is set for sun5i and efm32. (Yongbae Park)" Signed-off-by:
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Yongbae Park authored
The interrupt is enabled before the handler is set. Even this bug did not appear, it is potentially dangerous as it can lead to a NULL pointer dereference. Fix the error by enabling the interrupt after clockevents_config_and_register() is called. Cc: stable@vger.kernel.org Signed-off-by:
Yongbae Park <yongbae2@gmail.com> Signed-off-by:
Daniel Lezcano <daniel.lezcano@linaro.org>
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Yongbae Park authored
The initialisation of the efm32 clocksource first sets up the irq and only after that initialises the data needed for irq handling. In case this initialisation is delayed the irq handler would dereference a NULL pointer. I'm not aware of anything that could delay the process in such a way, but it's better to be safe than sorry, so setup the irq only when the clock event device is ready. Cc: stable@vger.kernel.org Acked-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:
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- 04 Mar, 2015 1 commit
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Ingo Molnar authored
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- 03 Mar, 2015 2 commits
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Linus Torvalds authored
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Daniel Vetter authored
This is a tricky story of the new atomic state handling and the legacy code fighting over each another. The bug at hand is an underrun of the framebuffer reference with subsequent hilarity caused by the load detect code. Which is peculiar since the the exact same code works fine as the implementation of the legacy setcrtc ioctl. Let's look at the ingredients: - Currently our code is a crazy mix of legacy modeset interfaces to set the parameters and half-baked atomic state tracking underneath. While this transition is going we're using the transitional plane helpers to update the atomic side (drm_plane_helper_disable/update and friends), i.e. plane->state->fb. Since the state structure owns the fb those functions take care of that themselves. The legacy state (specifically crtc->primary->fb) is still managed by the old code (and mostly by the drm core), with the fb reference counting done by callers (core drm for the ioctl or the i915 load detect code). The relevant commit is commit ea2c67bb Author: Matt Roper <matthew.d.roper@intel.com> Date: Tue Dec 23 10:41:52 2014 -0800 drm/i915: Move to atomic plane helpers (v9) - drm_plane_helper_disable has special code to handle multiple calls in a row - it checks plane->crtc == NULL and bails out. This is to match the proper atomic implementation which needs the crtc to get at the implied locking context atomic updates always need. See commit acf24a39 Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Tue Jul 29 15:33:05 2014 +0200 drm/plane-helper: transitional atomic plane helpers - The universal plane code split out the implicit primary plane from the CRTC into it's own full-blown drm_plane object. As part of that the setcrtc ioctl (which updated both the crtc mode and primary plane) learned to set crtc->primary->crtc on modeset to make sure the plane->crtc assignments statate up to date in commit e13161af Author: Matt Roper <matthew.d.roper@intel.com> Date: Tue Apr 1 15:22:38 2014 -0700 drm: Add drm_crtc_init_with_planes() (v2) Unfortunately we've forgotten to update the load detect code. Which wasn't a problem since the load detect modeset is temporary and always undone before we drop the locks. - Finally there is a organically grown history (i.e. don't ask) around who sets the legacy plane->fb for the various driver entry points. Originally updating that was the drivers duty, but for almost all places we've moved that (plus updating the refcounts) into the core. Again the exception is the load detect code. Taking all together the following happens: - The load detect code doesn't set crtc->primary->crtc. This is only really an issue on crtcs never before used or when userspace explicitly disabled the primary plane. - The plane helper glue code short-circuits because of that and leaves a non-NULL fb behind in plane->state->fb and plane->fb. The state fb isn't a real problem (it's properly refcounted on its own), it's just the canary. - Load detect code drops the reference for that fb, but doesn't set plane->fb = NULL. This is ok since it's still living in that old world where drivers had to clear the pointer but the core/callers handled the refcounting. - On the next modeset the drm core notices plane->fb and takes care of refcounting it properly by doing another unref. This drops the refcount to zero, leaving state->plane now pointing at freed memory. - intel_plane_duplicate_state still assume it owns a reference to that very state->fb and bad things start to happen. Fix this all by applying the same duct-tape as for the legacy setcrtc ioctl code and set crtc->primary->crtc properly. Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Rob Clark <robdclark@gmail.com> Cc: Paulo Zanoni <przanoni@gmail.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: Matt Roper <matthew.d.roper@intel.com> Reported-and-tested-by:
Linus Torvalds <torvalds@linux-foundation.org> Reported-by:
Paul Bolle <pebolle@tiscali.nl> Signed-off-by:
Daniel Vetter <daniel.vetter@intel.com> Signed-off-by:
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- 02 Mar, 2015 4 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpioLinus Torvalds authored
Pull GPIO fixes from Linus Walleij: "Two GPIO fixes: - Fix a translation problem in of_get_named_gpiod_flags() - Fix a long standing container_of() mistake in the TPS65912 driver" * tag 'gpio-v4.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: gpio: tps65912: fix wrong container_of arguments gpiolib: of: allow of_gpiochip_find_and_xlate to find more than one chip per node
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Linus Torvalds authored
Merge branch 'fixes-for-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal Pull thermal management fixes from Eduardo Valentin: "Specifics: - Several fixes in tmon tool. - Fixes in intel int340x for _ART and _TRT tables. - Add id for Avoton SoC into powerclamp driver. - Fixes in RCAR thermal driver to remove race conditions and fix fail path - Fixes in TI thermal driver: removal of unnecessary code and build fix if !CONFIG_PM_SLEEP - Cleanups in exynos thermal driver - Add stubs for include/linux/thermal.h. Now drivers using thermal calls but that also work without CONFIG_THERMAL will be able to compile for systems that don't care about thermal. Note: I am sending this pull on Rui's behalf while he fixes issues in his Linux box" * 'fixes-for-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal: thermal: int340x_thermal: Ignore missing _ART, _TRT tables thermal/intel_powerclamp: add id for Avoton SoC tools/thermal: tmon: silence 'set but not used' warnings tools/thermal: tmon: use pkg-config to determine library dependencies tools/thermal: tmon: support cross-compiling tools/thermal: tmon: add .gitignore tools/thermal: tmon: fixup tui windowing calculations tools/thermal: tmon: tui: don't hard-code dialog window size assumptions tools/thermal: tmon: add min/max macros tools/thermal: tmon: add --target-temp parameter thermal: exynos: Clean-up code to use oneline entry for exynos compatible table thermal: rcar: Make error and remove paths symmetrical with init thermal: rcar: Fix race condition between init and interrupt thermal: Introduce dummy functions when thermal is not defined ti-soc-thermal: Delete an unnecessary check before the function call "cpufreq_cooling_unregister" thermal: ti-soc-thermal: bandgap: Fix build warning if !CONFIG_PM_SLEEP
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git://neil.brown.name/mdLinus Torvalds authored
Pull md fixes from Neil Brown: "Three md fixes: - fix a read-balance problem that was reported 2 years ago, but that I never noticed the report :-( - fix for rare RAID6 problem causing incorrect bitmap updates when two devices fail. - add __ATTR_PREALLOC annotation now that it is possible" * tag 'md/4.0-fixes' of git://neil.brown.name/md: md: mark some attributes as pre-alloc raid5: check faulty flag for array status during recovery. md/raid1: fix read balance when a drive is write-mostly. -
git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metagLinus Torvalds authored
Pull arch/metag fix from James Hogan: "This is just a single patch to fix the KSTK_EIP() and KSTK_ESP() macros for metag which have always been erronously returning the PC and stack pointer of the task's kernel context rather than from its user context saved at entry from userland into the kernel, which affects the contents of /proc/<pid>/maps and /proc/<pid>/stat" * tag 'metag-fixes-v4.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: metag: Fix KSTK_EIP() and KSTK_ESP() macros
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- 01 Mar, 2015 4 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Ingo Molnar: "A CR4-shadow 32-bit init fix, plus two typo fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Init per-cpu shadow copy of CR4 on 32-bit CPUs too x86/platform/intel-mid: Fix trivial printk message typo in intel_mid_arch_setup() x86/cpu/intel: Fix trivial typo in intel_tlb_table[]
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer fixes from Ingo Molnar: "Three clockevents/clocksource driver fixes" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: pxa: Fix section mismatch clocksource: mtk: Fix race conditions in probe code clockevents: asm9260: Fix compilation error with sparc/sparc64 allyesconfig
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fixes from Ingo Molnar: "Two kprobes fixes and a handful of tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Make sparc64 arch point to sparc perf symbols: Define EM_AARCH64 for older OSes perf top: Fix SIGBUS on sparc64 perf tools: Fix probing for PERF_FLAG_FD_CLOEXEC flag perf tools: Fix pthread_attr_setaffinity_np build error perf tools: Define _GNU_SOURCE on pthread_attr_setaffinity_np feature check perf bench: Fix order of arguments to memcpy_alloc_mem kprobes/x86: Check for invalid ftrace location in __recover_probed_insn() kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull locking fix from Ingo Molnar: "An rtmutex deadlock path fixlet" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rtmutex: Set state back to running on error
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