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2020-07-20ptp: introduce a phase offset in the periodic output requestVladimir Oltean1-2/+17
Some PHCs like the ocelot/felix switch cannot emit generic periodic output, but just PPS (pulse per second) signals, which: - don't start from arbitrary absolute times, but are rather phase-aligned to the beginning of [the closest next] second. - have an optional phase offset relative to that beginning of the second. For those, it was initially established that they should reject any other absolute time for the PTP_PEROUT_REQUEST than 0.000000000 [1]. But when it actually came to writing an application [2] that makes use of this functionality, we realized that we can't really deal generically with PHCs that support absolute start time, and with PHCs that don't, without an explicit interface. Namely, in an ideal world, PHC drivers would ensure that the "perout.start" value written to hardware will result in a functional output. This means that if the PTP time has become in the past of this PHC's current time, it should be automatically fast-forwarded by the driver into a close enough future time that is known to work (note: this is necessary only if the hardware doesn't do this fast-forward by itself). But we don't really know what is the status for PHC drivers in use today, so in the general sense, user space would be risking to have a non-functional periodic output if it simply asked for a start time of 0.000000000. So let's introduce a flag for this type of reduced-functionality hardware, named PTP_PEROUT_PHASE. The start time is just "soon", the only thing we know for sure about this signal is that its rising edge events, Rn, occur at: Rn = perout.phase + n * perout.period The "phase" in the periodic output structure is simply an alias to the "start" time, since both cannot logically be specified at the same time. Therefore, the binary layout of the structure is not affected. [1]: https://patchwork.ozlabs.org/project/netdev/patch/20200320103726.32559-7-yangbo.lu@nxp.com/ [2]: https://www.mail-archive.com/linuxptp-devel@lists.sourceforge.net/msg04142.html Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-20ptp: add ability to configure duty cycle for periodic outputVladimir Oltean1-3/+14
There are external event timestampers (PHCs with support for PTP_EXTTS_REQUEST) that timestamp both event edges. When those edges are very close (such as in the case of a short pulse), there is a chance that the collected timestamp might be of the rising, or of the falling edge, we never know. There are also PHCs capable of generating periodic output with a configurable duty cycle. This is good news, because we can space the rising and falling edge out enough in time, that the risks to overrun the 1-entry timestamp FIFO of the extts PHC are lower (example: the perout PHC can be configured for a period of 1 second, and an "on" time of 0.5 seconds, resulting in a duty cycle of 50%). A flag is introduced for signaling that an on time is present in the perout request structure, for preserving compatibility. Logically speaking, the duty cycle cannot exceed 100% and the PTP core checks for this. PHC drivers that don't support this flag emit a periodic output of an unspecified duty cycle, same as before. The duty cycle is encoded as an "on" time, similar to the "start" and "period" times, and reuses the reserved space while preserving overall binary layout. Pahole reported before: struct ptp_perout_request { struct ptp_clock_time start; /* 0 16 */ struct ptp_clock_time period; /* 16 16 */ unsigned int index; /* 32 4 */ unsigned int flags; /* 36 4 */ unsigned int rsv[4]; /* 40 16 */ /* size: 56, cachelines: 1, members: 5 */ /* last cacheline: 56 bytes */ }; And now: struct ptp_perout_request { struct ptp_clock_time start; /* 0 16 */ struct ptp_clock_time period; /* 16 16 */ unsigned int index; /* 32 4 */ unsigned int flags; /* 36 4 */ union { struct ptp_clock_time on; /* 40 16 */ unsigned int rsv[4]; /* 40 16 */ }; /* 40 16 */ /* size: 56, cachelines: 1, members: 5 */ /* last cacheline: 56 bytes */ }; Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03ptp: Add adjust_phase to ptp_clock_caps capability.Vincent Cheng1-1/+3
Add adjust_phase to ptp_clock_caps capability to allow user to query if a PHC driver supports adjust phase with ioctl PTP_CLOCK_GETCAPS command. Signed-off-by: Vincent Cheng <vincent.cheng.xh@renesas.com> Reviewed-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-15ptp: Introduce strict checking of external time stamp options.Richard Cochran1-1/+3
User space may request time stamps on rising edges, falling edges, or both. However, the particular mode may or may not be supported in the hardware or in the driver. This patch adds a "strict" flag that tells drivers to ensure that the requested mode will be honored. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-15ptp: Validate requests to enable time stamping of external signals.Richard Cochran1-0/+1
Commit 415606588c61 ("PTP: introduce new versions of IOCTLs") introduced a new external time stamp ioctl that validates the flags. This patch extends the validation to ensure that at least one rising or falling edge flag is set when enabling external time stamps. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27ptp: correctly disable flags on old ioctlsJacob Keller1-0/+22
Commit 415606588c61 ("PTP: introduce new versions of IOCTLs", 2019-09-13) introduced new versions of the PTP ioctls which actually validate that the flags are acceptable values. As part of this, it cleared the flags value using a bitwise and+negation, in an attempt to prevent the old ioctl from accidentally enabling new features. This is incorrect for a couple of reasons. First, it results in accidentally preventing previously working flags on the request ioctl. By clearing the "valid" flags, we now no longer allow setting the enable, rising edge, or falling edge flags. Second, if we add new additional flags in the future, they must not be set by the old ioctl. (Since the flag wasn't checked before, we could potentially break userspace programs which sent garbage flag data. The correct way to resolve this is to check for and clear all but the originally valid flags. Create defines indicating which flags are correctly checked and interpreted by the original ioctls. Use these to clear any bits which will not be correctly interpreted by the original ioctls. In the future, new flags must be added to the VALID_FLAGS macros, but *not* to the V1_VALID_FLAGS macros. In this way, new features may be exposed over the v2 ioctls, but without breaking previous userspace which happened to not clear the flags value properly. The old ioctl will continue to behave the same way, while the new ioctl gains the benefit of using the flags fields. Cc: Richard Cochran <richardcochran@gmail.com> Cc: Felipe Balbi <felipe.balbi@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Christopher Hall <christopher.s.hall@intel.com> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-13PTP: add support for one-shot outputFelipe Balbi1-3/+3
Some controllers allow for a one-shot output pulse, in contrast to periodic output. Now that we have extensible versions of our IOCTLs, we can finally make use of the 'flags' field to pass a bit telling driver that if we want one-shot pulse output. Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Reviewed-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-13PTP: introduce new versions of IOCTLsFelipe Balbi1-1/+23
The current version of the IOCTL have a small problem which prevents us from extending the API by making use of reserved fields. In these new IOCTLs, we are now making sure that flags and rsv fields are zero which will allow us to extend the API in the future. Reviewed-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-09ptp: uapi: change _IOW to IOWR in PTP_SYS_OFFSET_EXTENDED definitionEugene Syromiatnikov1-1/+1
The ioctl command is read/write (or just read, if the fact that user space writes n_samples field is ignored). Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-10ptp: add PTP_SYS_OFFSET_EXTENDED ioctlMiroslav Lichvar1-0/+12
The PTP_SYS_OFFSET ioctl, which can be used to measure the offset between a PHC and the system clock, includes the total time that the driver needs to read the PHC timestamp. This typically involves reading of multiple PCI registers (sometimes in multiple iterations) and the register that contains the lowest bits of the timestamp is not read in the middle between the two readings of the system clock. This asymmetry causes the measured offset to have a significant error. Introduce a new ioctl, driver function, and helper functions, which allow the reading of the lowest register to be isolated from the other readings in order to reduce the asymmetry. The ioctl returns three timestamps for each measurement: - system time right before reading the lowest bits of the PHC timestamp - PHC time - system time immediately after reading the lowest bits of the PHC timestamp Cc: Richard Cochran <richardcochran@gmail.com> Cc: Jacob Keller <jacob.e.keller@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX license identifier to uapi header files with a licenseGreg Kroah-Hartman1-0/+1
Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-04ptp: Add PTP_SYS_OFFSET_PRECISE for driver crosstimestampingChristopher S. Hall1-1/+12
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: Christopher S. Hall <christopher.s.hall@intel.com> [jstultz: Commit subject tweaks] Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-03-21ptp: introduce programmable pins.Richard Cochran1-1/+38
This patch adds a pair of new ioctls to the PTP Hardware Clock device interface. Using the ioctls, user space programs can query each pin to find out its current function and also reprogram a different function if desired. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-01ptp: add an ioctl to compare PHC time with system timeRichard Cochran1-0/+14
This patch adds an ioctl for PTP Hardware Clock (PHC) devices that allows user space to measure the time offset between the PHC and the system clock. Rather than hard coding any kind of estimation algorithm into the kernel, this patch takes the more flexible approach of just delivering an array of raw clock readings. In that way, the user space clock servo may be adapted to new and different hardware clocks. Signed-off-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells1-0/+84
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>