- 06 Apr, 2016 40 commits
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 Modern Intel systems supports cross timestamping of the network device clock and Always Running Timer (ART) in hardware. This allows the device time and system time to be precisely correlated. The timestamp pair is returned through e1000e_phc_get_syncdevicetime() used by get_system_device_crosststamp(). The hardware cross-timestamp result is made available to applications through the PTP_SYS_OFFSET_PRECISE ioctl which calls e1000e_phc_getcrosststamp(). Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Acked-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by:
Christopher S. Hall <christopher.s.hall@intel.com> [jstultz: Reworked to use new interface, commit message tweaks] Signed-off-by:
John Stultz <john.stultz@linaro.org> (cherry picked from commit 01d7ada5) Signed-off-by:
Tim Gardner <tim.gardner@canonical.com>
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Tim Gardner authored
BugLink: http://bugs.launchpad.net/bugs/1519625Signed-off-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 Currently, network /system cross-timestamping is performed in the PTP_SYS_OFFSET ioctl. The PTP clock driver reads gettimeofday() and the gettime64() callback provided by the driver. The cross-timestamp is best effort where the latency between the capture of system time (getnstimeofday()) and the device time (driver callback) may be significant. The getcrosststamp() callback and corresponding PTP_SYS_OFFSET_PRECISE ioctl allows the driver to perform this device/system correlation when for example cross timestamp hardware is available. Modern Intel systems can do this for onboard Ethernet controllers using the ART counter. There is virtually zero latency between captures of the ART and network device clock. The capabilities ioctl (PTP_CLOCK_GETCAPS), is augmented allowing applications to query whether or not drivers implement the getcrosststamp callback, providing more precise cross timestamping. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Acked-by:
Richard Cochran <richardcochran@gmail.com> Signed-off-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 On modern Intel systems TSC is derived from the new Always Running Timer (ART). ART can be captured simultaneous to the capture of audio and network device clocks, allowing a correlation between timebases to be constructed. Upon capture, the driver converts the captured ART value to the appropriate system clock using the correlated clocksource mechanism. On systems that support ART a new CPUID leaf (0x15) returns parameters “m” and “n” such that: TSC_value = (ART_value * m) / n + k [n >= 1] [k is an offset that can adjusted by a privileged agent. The IA32_TSC_ADJUST MSR is an example of an interface to adjust k. See 17.14.4 of the Intel SDM for more details] Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Ingo Molnar authored
BugLink: http://bugs.launchpad.net/bugs/1519625 Newer GCC versions trigger the following warning: kernel/time/timekeeping.c: In function ‘get_device_system_crosststamp’: kernel/time/timekeeping.c:987:5: warning: ‘clock_was_set_seq’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (discontinuity) { ^ kernel/time/timekeeping.c:1045:15: note: ‘clock_was_set_seq’ was declared here unsigned int clock_was_set_seq; ^ GCC clearly is unable to recognize that the 'do_interp' boolean tracks the initialization status of 'clock_was_set_seq'. The GCC version used was: gcc version 5.3.1 20151207 (Red Hat 5.3.1-2) (GCC) Work it around by initializing clock_was_set_seq to 0. Compilers that are able to recognize the code flow will eliminate the unnecessary initialization. Acked-by:
Ingo Molnar <mingo@kernel.org> (cherry picked from commit 6436257b) Signed-off-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 Another representative use case of time sync and the correlated clocksource (in addition to PTP noted above) is PTP synchronized audio. In a streaming application, as an example, samples will be sent and/or received by multiple devices with a presentation time that is in terms of the PTP master clock. Synchronizing the audio output on these devices requires correlating the audio clock with the PTP master clock. The more precise this correlation is, the better the audio quality (i.e. out of sync audio sounds bad). From an application standpoint, to correlate the PTP master clock with the audio device clock, the system clock is used as a intermediate timebase. The transforms such an application would perform are: System Clock <-> Audio clock System Clock <-> Network Device Clock [<-> PTP Master Clock] Modern Intel platforms can perform a more accurate cross timestamp in hardware (ART,audio device clock). The audio driver requires ART->system time transforms -- the same as required for the network driver. These platforms offload audio processing (including cross-timestamps) to a DSP which to ensure uninterrupted audio processing, communicates and response to the host only once every millsecond. As a result is takes up to a millisecond for the DSP to receive a request, the request is processed by the DSP, the audio output hardware is polled for completion, the result is copied into shared memory, and the host is notified. All of these operation occur on a millisecond cadence. This transaction requires about 2 ms, but under heavier workloads it may take up to 4 ms. Adding a history allows these slow devices the option of providing an ART value outside of the current interval. In this case, the callback provided is an accessor function for the previously obtained counter value. If get_system_device_crosststamp() receives a counter value previous to cycle_last, it consults the history provided as an argument in history_ref and interpolates the realtime and monotonic raw system time using the provided counter value. If there are any clock discontinuities, e.g. from calling settimeofday(), the monotonic raw time is interpolated in the usual way, but the realtime clock time is adjusted by scaling the monotonic raw adjustment. When an accessor function is used a history argument *must* be provided. The history is initialized using ktime_get_snapshot() and must be called before the counter values are read. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 ACKNOWLEDGMENT: cross timestamp code was developed by Thomas Gleixner <tglx@linutronix.de>. It has changed considerably and any mistakes are mine. The precision with which events on multiple networked systems can be synchronized using, as an example, PTP (IEEE 1588, 802.1AS) is limited by the precision of the cross timestamps between the system clock and the device (timestamp) clock. Precision here is the degree of simultaneity when capturing the cross timestamp. Currently the PTP cross timestamp is captured in software using the PTP device driver ioctl PTP_SYS_OFFSET. Reads of the device clock are interleaved with reads of the realtime clock. At best, the precision of this cross timestamp is on the order of several microseconds due to software latencies. Sub-microsecond precision is required for industrial control and some media applications. To achieve this level of precision hardware supported cross timestamping is needed. The function get_device_system_crosstimestamp() allows device drivers to return a cross timestamp with system time properly scaled to nanoseconds. The realtime value is needed to discipline that clock using PTP and the monotonic raw value is used for applications that don't require a "real" time, but need an unadjusted clock time. The get_device_system_crosstimestamp() code calls back into the driver to ensure that the system counter is within the current timekeeping update interval. Modern Intel hardware provides an Always Running Timer (ART) which is exactly related to TSC through a known frequency ratio. The ART is routed to devices on the system and is used to precisely and simultaneously capture the device clock with the ART. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 The code in ktime_get_snapshot() is a superset of the code in ktime_get_raw_and_real() code. Further, ktime_get_raw_and_real() is called only by the PPS code, pps_get_ts(). Consolidate the pps_get_ts() code into a single function calling ktime_get_snapshot() and eliminate ktime_get_raw_and_real(). A side effect of this is that the raw and real results of pps_get_ts() correspond to exactly the same clock cycle. Previously these values represented separate reads of the system clock. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 In the current timekeeping code there isn't any interface to atomically capture the current relationship between the system counter and system time. ktime_get_snapshot() returns this triple (counter, monotonic raw, realtime) in the system_time_snapshot struct. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by:
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Christopher S. Hall authored
BugLink: http://bugs.launchpad.net/bugs/1519625 The timekeeping code does not currently provide a way to translate externally provided clocksource cycles to system time. The cycle count is always provided by the result clocksource read() method internal to the timekeeping code. The added function timekeeping_cycles_to_ns() calculated a nanosecond value from a cycle count that can be added to tk_read_base.base value yielding the current system time. This allows clocksource cycle values external to the timekeeping code to provide a cycle count that can be transformed to system time. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by:
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Yang Yingliang authored
BugLink: http://bugs.launchpad.net/bugs/1519625 The clocksource validation which makes sure that the newly read value is not smaller than the last value only works if the clocksource mask is 64bit, i.e. the counter is 64bit wide. But we want to use that mechanism also for clocksources which are less than 64bit wide. So instead of checking whether bit 63 is set, we check whether the most significant bit of the clocksource mask is set in the delta result. If it is set, we return 0. [ tglx: Simplified the implementation, added a comment and massaged the commit message ] Suggested-by:
Yang Yingliang <yangyingliang@huawei.com> Cc: <linux-arm-kernel@lists.infradead.org> Link: http://lkml.kernel.org/r/56349607.6070708@huawei.comSigned-off-by:
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John Stultz authored
BugLink: http://bugs.launchpad.net/bugs/1519625 Thus its been occasionally noted that users have seen confusing warnings like: Adjusting tsc more than 11% (5941981 vs 7759439) We try to limit the maximum total adjustment to 11% (10% tick adjustment + 0.5% frequency adjustment). But this is done by bounding the requested adjustment values, and the internal steering that is done by tracking the error from what was requested and what was applied, does not have any such limits. This is usually not problematic, but in some cases has a risk that an adjustment could cause the clocksource mult value to overflow, so its an indication things are outside of what is expected. It ends up most of the reports of this 11% warning are on systems using chrony, which utilizes the adjtimex() ADJ_TICK interface (which allows a +-10% adjustment). The original rational for ADJ_TICK unclear to me but my assumption it was originally added to allow broken systems to get a big constant correction at boot (see adjtimex userspace package for an example) which would allow the system to work w/ ntpd's 0.5% adjustment limit. Chrony uses ADJ_TICK to make very aggressive short term corrections (usually right at startup). Which push us close enough to the max bound that a few late ticks can cause the internal steering to push past the max adjust value (tripping the warning). Thus this patch adds some extra logic to enforce the max adjustment cap in the internal steering. Note: This has the potential to slow corrections when the ADJ_TICK value is furthest away from the default value. So it would be good to get some testing from folks using chrony, to make sure we don't cause any troubles there. Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Tested-by:
Miroslav Lichvar <mlichvar@redhat.com> Reported-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
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DengChao authored
BugLink: http://bugs.launchpad.net/bugs/1519625 In order to fix Y2038 issues in the ntp code we will need replace get_seconds() with ktime_get_real_seconds() but as the ntp code uses the timekeeping lock which is also used by ktime_get_real_seconds(), we need a version without locking. Add a new function __ktime_get_real_seconds() in timekeeping to do this. Reviewed-by:
DengChao <chao.deng@linaro.org> Signed-off-by:
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John Stultz authored
BugLink: http://bugs.launchpad.net/bugs/1519625 For adjtimex()'s ADJ_SETOFFSET, make sure the tv_usec value is sane. We might multiply them later which can cause an overflow and undefined behavior. This patch introduces new helper functions to simplify the checking code and adds comments to clarify Orginally this patch was by Sasha Levin, but I've basically rewritten it, so he should get credit for finding the issue and I should get the blame for any mistakes made since. Also, credit to Richard Cochran for the phrasing used in the comment for what is considered valid here. Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Reported-by:
Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
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Loc Ho authored
BugLink: http://bugs.launchpad.net/bugs/1561604 Add X-Gene SoC and PMD PLL clocks support for v2 hardware. X-Gene SoC v2 and above use an slightly different SoC and PMD PLL hardware logic. Signed-off-by:
Loc Ho <lho@apm.com> Signed-off-by:
Stephen Boyd <sboyd@codeaurora.org> (cherry picked from commit 47727beb) Signed-off-by:
Craig Magina <craig.magina@canonical.com> Signed-off-by:
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Jiri Olsa authored
BugLink: http://bugs.launchpad.net/bugs/1559914 Using PAGE_SIZE buffers makes the WRMSR to PERF_GLOBAL_CTRL in intel_pmu_enable_all() mysteriously hang on Core2. As a workaround, we don't do this. The hard lockup is easily triggered by running 'perf test attr' repeatedly. Most of the time it gets stuck on sample session with small periods. # perf test attr -vv 14: struct perf_event_attr setup : --- start --- ... 'PERF_TEST_ATTR=/tmp/tmpuEKz3B /usr/bin/perf record -o /tmp/tmpuEKz3B/perf.data -c 123 kill >/dev/null 2>&1' ret 1 Reported-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by:
Andi Kleen <ak@linux.intel.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20160301190352.GA8355@krava.redhat.comSigned-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914 Now that all functionality has been moved to arch/x86/events/, move the perf_event.h header and adjust include paths. Signed-off-by:
Borislav Petkov <bp@suse.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1455098123-11740-18-git-send-email-bp@alien8.deSigned-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914 Start moving the Intel bits. Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914 We distribute those in vendor subdirs, starting with .../events/amd/. Signed-off-by:
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Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1559914 Also, keep the churn at minimum by adjusting the include "perf_event.h" when each file gets moved. Signed-off-by:
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Mika Westerberg authored
BugLink: http://bugs.launchpad.net/bugs/1520139 I2C host controller need to be configured properly in order to meet I2C timings specified in the I2C protocol specification. Some Intel Broxton based machines do not have this information in the ACPI namespace (or the boot firmware does not support ACPI at all) so we use build-in device properties instead. Signed-off-by:
Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Lee Jones <lee.jones@linaro.org> (cherry picked from commit 0343b2f4) Signed-off-by:
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Tim Gardner authored
Ignore: yes Signed-off-by:
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