linux-stable/drivers/ptp/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
#
# PTP clock support configuration
#
menu "PTP clock support"
config PTP_1588_CLOCK
tristate "PTP clock support"
depends on NET && POSIX_TIMERS
ethernet: fix PTP_1588_CLOCK dependencies The 'imply' keyword does not do what most people think it does, it only politely asks Kconfig to turn on another symbol, but does not prevent it from being disabled manually or built as a loadable module when the user is built-in. In the ICE driver, the latter now causes a link failure: aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_eth_ioctl': ice_main.c:(.text+0x13b0): undefined reference to `ice_ptp_get_ts_config' ice_main.c:(.text+0x13b0): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_get_ts_config' aarch64-linux-ld: ice_main.c:(.text+0x13bc): undefined reference to `ice_ptp_set_ts_config' ice_main.c:(.text+0x13bc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_set_ts_config' aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_prepare_for_reset': ice_main.c:(.text+0x31fc): undefined reference to `ice_ptp_release' ice_main.c:(.text+0x31fc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_release' aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_rebuild': This is a recurring problem in many drivers, and we have discussed it several times befores, without reaching a consensus. I'm providing a link to the previous email thread for reference, which discusses some related problems. To solve the dependency issue better than the 'imply' keyword, introduce a separate Kconfig symbol "CONFIG_PTP_1588_CLOCK_OPTIONAL" that any driver can depend on if it is able to use PTP support when available, but works fine without it. Whenever CONFIG_PTP_1588_CLOCK=m, those drivers are then prevented from being built-in, the same way as with a 'depends on PTP_1588_CLOCK || !PTP_1588_CLOCK' dependency that does the same trick, but that can be rather confusing when you first see it. Since this should cover the dependencies correctly, the IS_REACHABLE() hack in the header is no longer needed now, and can be turned back into a normal IS_ENABLED() check. Any driver that gets the dependency wrong will now cause a link time failure rather than being unable to use PTP support when that is in a loadable module. However, the two recently added ptp_get_vclocks_index() and ptp_convert_timestamp() interfaces are only called from builtin code with ethtool and socket timestamps, so keep the current behavior by stubbing those out completely when PTP is in a loadable module. This should be addressed properly in a follow-up. As Richard suggested, we may want to actually turn PTP support into a 'bool' option later on, preventing it from being a loadable module altogether, which would be one way to solve the problem with the ethtool interface. Fixes: 06c16d89d2cb ("ice: register 1588 PTP clock device object for E810 devices") Link: https://lore.kernel.org/netdev/20210804121318.337276-1-arnd@kernel.org/ Link: https://lore.kernel.org/netdev/CAK8P3a06enZOf=XyZ+zcAwBczv41UuCTz+=0FMf2gBz1_cOnZQ@mail.gmail.com/ Link: https://lore.kernel.org/netdev/CAK8P3a3=eOxE-K25754+fB_-i_0BZzf9a9RfPTX3ppSwu9WZXw@mail.gmail.com/ Link: https://lore.kernel.org/netdev/20210726084540.3282344-1-arnd@kernel.org/ Acked-by: Shannon Nelson <snelson@pensando.io> Acked-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20210812183509.1362782-1-arnd@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-12 18:33:58 +00:00
default ETHERNET
select PPS
net: ptp: move PTP classifier in its own file This commit fixes a build error reported by Fengguang, that is triggered when CONFIG_NETWORK_PHY_TIMESTAMPING is not set: ERROR: "ptp_classify_raw" [drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.ko] undefined! The fix is to introduce its own file for the PTP BPF classifier, so that PTP_1588_CLOCK and/or NETWORK_PHY_TIMESTAMPING can select it independently from each other. IXP4xx driver on ARM needs to select it as well since it does not seem to select PTP_1588_CLOCK or similar that would pull it in automatically. This also allows for hiding all of the internals of the BPF PTP program inside that file, and only exporting relevant API bits to drivers. This patch also adds a kdoc documentation of ptp_classify_raw() API to make it clear that it can return PTP_CLASS_* defines. Also, the BPF program has been translated into bpf_asm code, so that it can be more easily read and altered (extensively documented in [1]). In the kernel tree under tools/net/ we have bpf_asm and bpf_dbg tools, so the commented program can simply be translated via `./bpf_asm -c prog` where prog is a file that contains the commented code. This makes it easily readable/verifiable and when there's a need to change something, jump offsets etc do not need to be replaced manually which can be very error prone. Instead, a newly translated version via bpf_asm can simply replace the old code. I have checked opcode diffs before/after and it's the very same filter. [1] Documentation/networking/filter.txt Fixes: 164d8c666521 ("net: ptp: do not reimplement PTP/BPF classifier") Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Jiri Benc <jbenc@redhat.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-01 14:20:23 +00:00
select NET_PTP_CLASSIFY
help
The IEEE 1588 standard defines a method to precisely
synchronize distributed clocks over Ethernet networks. The
standard defines a Precision Time Protocol (PTP), which can
be used to achieve synchronization within a few dozen
microseconds. In addition, with the help of special hardware
time stamping units, it can be possible to achieve
synchronization to within a few hundred nanoseconds.
This driver adds support for PTP clocks as character
devices. If you want to use a PTP clock, then you should
also enable at least one clock driver as well.
To compile this driver as a module, choose M here: the module
will be called ptp.
ethernet: fix PTP_1588_CLOCK dependencies The 'imply' keyword does not do what most people think it does, it only politely asks Kconfig to turn on another symbol, but does not prevent it from being disabled manually or built as a loadable module when the user is built-in. In the ICE driver, the latter now causes a link failure: aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_eth_ioctl': ice_main.c:(.text+0x13b0): undefined reference to `ice_ptp_get_ts_config' ice_main.c:(.text+0x13b0): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_get_ts_config' aarch64-linux-ld: ice_main.c:(.text+0x13bc): undefined reference to `ice_ptp_set_ts_config' ice_main.c:(.text+0x13bc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_set_ts_config' aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_prepare_for_reset': ice_main.c:(.text+0x31fc): undefined reference to `ice_ptp_release' ice_main.c:(.text+0x31fc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_release' aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_rebuild': This is a recurring problem in many drivers, and we have discussed it several times befores, without reaching a consensus. I'm providing a link to the previous email thread for reference, which discusses some related problems. To solve the dependency issue better than the 'imply' keyword, introduce a separate Kconfig symbol "CONFIG_PTP_1588_CLOCK_OPTIONAL" that any driver can depend on if it is able to use PTP support when available, but works fine without it. Whenever CONFIG_PTP_1588_CLOCK=m, those drivers are then prevented from being built-in, the same way as with a 'depends on PTP_1588_CLOCK || !PTP_1588_CLOCK' dependency that does the same trick, but that can be rather confusing when you first see it. Since this should cover the dependencies correctly, the IS_REACHABLE() hack in the header is no longer needed now, and can be turned back into a normal IS_ENABLED() check. Any driver that gets the dependency wrong will now cause a link time failure rather than being unable to use PTP support when that is in a loadable module. However, the two recently added ptp_get_vclocks_index() and ptp_convert_timestamp() interfaces are only called from builtin code with ethtool and socket timestamps, so keep the current behavior by stubbing those out completely when PTP is in a loadable module. This should be addressed properly in a follow-up. As Richard suggested, we may want to actually turn PTP support into a 'bool' option later on, preventing it from being a loadable module altogether, which would be one way to solve the problem with the ethtool interface. Fixes: 06c16d89d2cb ("ice: register 1588 PTP clock device object for E810 devices") Link: https://lore.kernel.org/netdev/20210804121318.337276-1-arnd@kernel.org/ Link: https://lore.kernel.org/netdev/CAK8P3a06enZOf=XyZ+zcAwBczv41UuCTz+=0FMf2gBz1_cOnZQ@mail.gmail.com/ Link: https://lore.kernel.org/netdev/CAK8P3a3=eOxE-K25754+fB_-i_0BZzf9a9RfPTX3ppSwu9WZXw@mail.gmail.com/ Link: https://lore.kernel.org/netdev/20210726084540.3282344-1-arnd@kernel.org/ Acked-by: Shannon Nelson <snelson@pensando.io> Acked-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20210812183509.1362782-1-arnd@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-12 18:33:58 +00:00
config PTP_1588_CLOCK_OPTIONAL
tristate
default y if PTP_1588_CLOCK=n
default PTP_1588_CLOCK
help
Drivers that can optionally use the PTP_1588_CLOCK framework
should depend on this symbol to prevent them from being built
into vmlinux while the PTP support itself is in a loadable
module.
If PTP support is disabled, this dependency will still be
met, and drivers refer to dummy helpers.
config PTP_1588_CLOCK_DTE
tristate "Broadcom DTE as PTP clock"
depends on PTP_1588_CLOCK
depends on NET && HAS_IOMEM
depends on ARCH_BCM_MOBILE || (ARCH_BCM_IPROC && !(ARCH_BCM_NSP || ARCH_BCM_5301X)) || COMPILE_TEST
default y
help
This driver adds support for using the Digital timing engine
(DTE) in the Broadcom SoC's as a PTP clock.
The clock can be used in both wired and wireless networks
for PTP purposes.
To compile this driver as a module, choose M here: the module
will be called ptp_dte.
config PTP_1588_CLOCK_QORIQ
tristate "Freescale QorIQ 1588 timer as PTP clock"
depends on GIANFAR || FSL_DPAA_ETH || FSL_DPAA2_ETH || FSL_ENETC || FSL_ENETC_VF || COMPILE_TEST
ptp_clock: Allow for it to be optional In order to break the hard dependency between the PTP clock subsystem and ethernet drivers capable of being clock providers, this patch provides simple PTP stub functions to allow linkage of those drivers into the kernel even when the PTP subsystem is configured out. Drivers must be ready to accept NULL from ptp_clock_register() in that case. And to make it possible for PTP to be configured out, the select statement in those driver's Kconfig menu entries is converted to the new "imply" statement. This way the PTP subsystem may have Kconfig dependencies of its own, such as POSIX_TIMERS, without having to make those ethernet drivers unavailable if POSIX timers are cconfigured out. And when support for POSIX timers is selected again then the default config option for PTP clock support will automatically be adjusted accordingly. The pch_gbe driver is a bit special as it relies on extra code in drivers/ptp/ptp_pch.c. Therefore we let the make process descend into drivers/ptp/ even if PTP_1588_CLOCK is unselected. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Link: http://lkml.kernel.org/r/1478841010-28605-4-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-11 05:10:07 +00:00
depends on PTP_1588_CLOCK
default y
help
This driver adds support for using the Freescale QorIQ 1588
timer as a PTP clock. This clock is only useful if your PTP
programs are getting hardware time stamps on the PTP Ethernet
packets using the SO_TIMESTAMPING API.
To compile this driver as a module, choose M here: the module
will be called ptp-qoriq.
comment "Enable PHYLIB and NETWORK_PHY_TIMESTAMPING to see the additional clocks."
depends on PHYLIB=n || NETWORK_PHY_TIMESTAMPING=n
config DP83640_PHY
tristate "Driver for the National Semiconductor DP83640 PHYTER"
depends on NETWORK_PHY_TIMESTAMPING
depends on PHYLIB
ptp_clock: Allow for it to be optional In order to break the hard dependency between the PTP clock subsystem and ethernet drivers capable of being clock providers, this patch provides simple PTP stub functions to allow linkage of those drivers into the kernel even when the PTP subsystem is configured out. Drivers must be ready to accept NULL from ptp_clock_register() in that case. And to make it possible for PTP to be configured out, the select statement in those driver's Kconfig menu entries is converted to the new "imply" statement. This way the PTP subsystem may have Kconfig dependencies of its own, such as POSIX_TIMERS, without having to make those ethernet drivers unavailable if POSIX timers are cconfigured out. And when support for POSIX timers is selected again then the default config option for PTP clock support will automatically be adjusted accordingly. The pch_gbe driver is a bit special as it relies on extra code in drivers/ptp/ptp_pch.c. Therefore we let the make process descend into drivers/ptp/ even if PTP_1588_CLOCK is unselected. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Link: http://lkml.kernel.org/r/1478841010-28605-4-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-11 05:10:07 +00:00
depends on PTP_1588_CLOCK
select CRC32
help
Supports the DP83640 PHYTER with IEEE 1588 features.
This driver adds support for using the DP83640 as a PTP
clock. This clock is only useful if your PTP programs are
getting hardware time stamps on the PTP Ethernet packets
using the SO_TIMESTAMPING API.
In order for this to work, your MAC driver must also
implement the skb_tx_timestamp() function.
config PTP_1588_CLOCK_INES
tristate "ZHAW InES PTP time stamping IP core"
depends on NETWORK_PHY_TIMESTAMPING
depends on HAS_IOMEM
depends on PHYLIB
depends on PTP_1588_CLOCK
help
This driver adds support for using the ZHAW InES 1588 IP
core. This clock is only useful if the MII bus of your MAC
is wired up to the core.
config PTP_1588_CLOCK_PCH
tristate "Intel PCH EG20T as PTP clock"
depends on X86_32 || COMPILE_TEST
depends on HAS_IOMEM && PCI
depends on NET
ethernet: fix PTP_1588_CLOCK dependencies The 'imply' keyword does not do what most people think it does, it only politely asks Kconfig to turn on another symbol, but does not prevent it from being disabled manually or built as a loadable module when the user is built-in. In the ICE driver, the latter now causes a link failure: aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_eth_ioctl': ice_main.c:(.text+0x13b0): undefined reference to `ice_ptp_get_ts_config' ice_main.c:(.text+0x13b0): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_get_ts_config' aarch64-linux-ld: ice_main.c:(.text+0x13bc): undefined reference to `ice_ptp_set_ts_config' ice_main.c:(.text+0x13bc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_set_ts_config' aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_prepare_for_reset': ice_main.c:(.text+0x31fc): undefined reference to `ice_ptp_release' ice_main.c:(.text+0x31fc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_release' aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_rebuild': This is a recurring problem in many drivers, and we have discussed it several times befores, without reaching a consensus. I'm providing a link to the previous email thread for reference, which discusses some related problems. To solve the dependency issue better than the 'imply' keyword, introduce a separate Kconfig symbol "CONFIG_PTP_1588_CLOCK_OPTIONAL" that any driver can depend on if it is able to use PTP support when available, but works fine without it. Whenever CONFIG_PTP_1588_CLOCK=m, those drivers are then prevented from being built-in, the same way as with a 'depends on PTP_1588_CLOCK || !PTP_1588_CLOCK' dependency that does the same trick, but that can be rather confusing when you first see it. Since this should cover the dependencies correctly, the IS_REACHABLE() hack in the header is no longer needed now, and can be turned back into a normal IS_ENABLED() check. Any driver that gets the dependency wrong will now cause a link time failure rather than being unable to use PTP support when that is in a loadable module. However, the two recently added ptp_get_vclocks_index() and ptp_convert_timestamp() interfaces are only called from builtin code with ethtool and socket timestamps, so keep the current behavior by stubbing those out completely when PTP is in a loadable module. This should be addressed properly in a follow-up. As Richard suggested, we may want to actually turn PTP support into a 'bool' option later on, preventing it from being a loadable module altogether, which would be one way to solve the problem with the ethtool interface. Fixes: 06c16d89d2cb ("ice: register 1588 PTP clock device object for E810 devices") Link: https://lore.kernel.org/netdev/20210804121318.337276-1-arnd@kernel.org/ Link: https://lore.kernel.org/netdev/CAK8P3a06enZOf=XyZ+zcAwBczv41UuCTz+=0FMf2gBz1_cOnZQ@mail.gmail.com/ Link: https://lore.kernel.org/netdev/CAK8P3a3=eOxE-K25754+fB_-i_0BZzf9a9RfPTX3ppSwu9WZXw@mail.gmail.com/ Link: https://lore.kernel.org/netdev/20210726084540.3282344-1-arnd@kernel.org/ Acked-by: Shannon Nelson <snelson@pensando.io> Acked-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20210812183509.1362782-1-arnd@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-12 18:33:58 +00:00
depends on PTP_1588_CLOCK
help
This driver adds support for using the PCH EG20T as a PTP
clock. The hardware supports time stamping of PTP packets
when using the end-to-end delay (E2E) mechanism. The peer
delay mechanism (P2P) is not supported.
This clock is only useful if your PTP programs are getting
hardware time stamps on the PTP Ethernet packets using the
SO_TIMESTAMPING API.
To compile this driver as a module, choose M here: the module
will be called ptp_pch.
config PTP_1588_CLOCK_KVM
tristate "KVM virtual PTP clock"
depends on PTP_1588_CLOCK
ptp: arm/arm64: Enable ptp_kvm for arm/arm64 Currently, there is no mechanism to keep time sync between guest and host in arm/arm64 virtualization environment. Time in guest will drift compared with host after boot up as they may both use third party time sources to correct their time respectively. The time deviation will be in order of milliseconds. But in some scenarios,like in cloud environment, we ask for higher time precision. kvm ptp clock, which chooses the host clock source as a reference clock to sync time between guest and host, has been adopted by x86 which takes the time sync order from milliseconds to nanoseconds. This patch enables kvm ptp clock for arm/arm64 and improves clock sync precision significantly. Test result comparisons between with kvm ptp clock and without it in arm/arm64 are as follows. This test derived from the result of command 'chronyc sources'. we should take more care of the last sample column which shows the offset between the local clock and the source at the last measurement. no kvm ptp in guest: MS Name/IP address Stratum Poll Reach LastRx Last sample ======================================================================== ^* dns1.synet.edu.cn 2 6 377 13 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 21 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 29 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 37 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 45 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 53 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 61 +1040us[+1581us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 4 -130us[ +796us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 12 -130us[ +796us] +/- 21ms ^* dns1.synet.edu.cn 2 6 377 20 -130us[ +796us] +/- 21ms in host: MS Name/IP address Stratum Poll Reach LastRx Last sample ======================================================================== ^* 120.25.115.20 2 7 377 72 -470us[ -603us] +/- 18ms ^* 120.25.115.20 2 7 377 92 -470us[ -603us] +/- 18ms ^* 120.25.115.20 2 7 377 112 -470us[ -603us] +/- 18ms ^* 120.25.115.20 2 7 377 2 +872ns[-6808ns] +/- 17ms ^* 120.25.115.20 2 7 377 22 +872ns[-6808ns] +/- 17ms ^* 120.25.115.20 2 7 377 43 +872ns[-6808ns] +/- 17ms ^* 120.25.115.20 2 7 377 63 +872ns[-6808ns] +/- 17ms ^* 120.25.115.20 2 7 377 83 +872ns[-6808ns] +/- 17ms ^* 120.25.115.20 2 7 377 103 +872ns[-6808ns] +/- 17ms ^* 120.25.115.20 2 7 377 123 +872ns[-6808ns] +/- 17ms The dns1.synet.edu.cn is the network reference clock for guest and 120.25.115.20 is the network reference clock for host. we can't get the clock error between guest and host directly, but a roughly estimated value will be in order of hundreds of us to ms. with kvm ptp in guest: chrony has been disabled in host to remove the disturb by network clock. MS Name/IP address Stratum Poll Reach LastRx Last sample ======================================================================== * PHC0 0 3 377 8 -7ns[ +1ns] +/- 3ns * PHC0 0 3 377 8 +1ns[ +16ns] +/- 3ns * PHC0 0 3 377 6 -4ns[ -0ns] +/- 6ns * PHC0 0 3 377 6 -8ns[ -12ns] +/- 5ns * PHC0 0 3 377 5 +2ns[ +4ns] +/- 4ns * PHC0 0 3 377 13 +2ns[ +4ns] +/- 4ns * PHC0 0 3 377 12 -4ns[ -6ns] +/- 4ns * PHC0 0 3 377 11 -8ns[ -11ns] +/- 6ns * PHC0 0 3 377 10 -14ns[ -20ns] +/- 4ns * PHC0 0 3 377 8 +4ns[ +5ns] +/- 4ns The PHC0 is the ptp clock which choose the host clock as its source clock. So we can see that the clock difference between host and guest is in order of ns. Cc: Mark Rutland <mark.rutland@arm.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201209060932.212364-8-jianyong.wu@arm.com
2020-12-09 06:09:30 +00:00
depends on (KVM_GUEST && X86) || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER)
default y
help
This driver adds support for using kvm infrastructure as a PTP
clock. This clock is only useful if you are using KVM guests.
To compile this driver as a module, choose M here: the module
will be called ptp_kvm.
config PTP_1588_CLOCK_IDT82P33
tristate "IDT 82P33xxx PTP clock"
depends on PTP_1588_CLOCK && I2C
default n
help
This driver adds support for using the IDT 82P33xxx as a PTP
clock. This clock is only useful if your time stamping MAC
is connected to the IDT chip.
To compile this driver as a module, choose M here: the module
will be called ptp_idt82p33.
config PTP_1588_CLOCK_IDTCM
tristate "IDT CLOCKMATRIX as PTP clock"
depends on PTP_1588_CLOCK && I2C
default n
help
This driver adds support for using IDT CLOCKMATRIX(TM) as a PTP
clock. This clock is only useful if your time stamping MAC
is connected to the IDT chip.
To compile this driver as a module, choose M here: the module
will be called ptp_clockmatrix.
config PTP_1588_CLOCK_VMW
tristate "VMware virtual PTP clock"
depends on ACPI && HYPERVISOR_GUEST && X86
depends on PTP_1588_CLOCK
help
This driver adds support for using VMware virtual precision
clock device as a PTP clock. This is only useful in virtual
machines running on VMware virtual infrastructure.
To compile this driver as a module, choose M here: the module
will be called ptp_vmw.
config PTP_1588_CLOCK_OCP
tristate "OpenCompute TimeCard as PTP clock"
depends on PTP_1588_CLOCK
depends on HAS_IOMEM && PCI
depends on I2C && MTD
depends on SERIAL_8250
depends on !S390
depends on COMMON_CLK
select NET_DEVLINK
select CRC16
help
This driver adds support for an OpenCompute time card.
The OpenCompute time card is an atomic clock along with
a GPS receiver that provides a Grandmaster clock source
for a PTP enabled network.
More information is available at http://www.timingcard.com/
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