linux/drivers/ptp/Kconfig
Daniel Borkmann 408eccce32 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: 164d8c6665 ("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 16:43:18 -04:00

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#
# PTP clock support configuration
#
menu "PTP clock support"
config PTP_1588_CLOCK
tristate "PTP clock support"
select PPS
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.
config PTP_1588_CLOCK_GIANFAR
tristate "Freescale eTSEC as PTP clock"
depends on GIANFAR
select PTP_1588_CLOCK
default y
help
This driver adds support for using the eTSEC 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 gianfar_ptp.
config PTP_1588_CLOCK_IXP46X
tristate "Intel IXP46x as PTP clock"
depends on IXP4XX_ETH
select PTP_1588_CLOCK
default y
help
This driver adds support for using the IXP46X 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_ixp46x.
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
select PTP_1588_CLOCK
---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_PCH
tristate "Intel PCH EG20T as PTP clock"
depends on X86 || COMPILE_TEST
depends on HAS_IOMEM
select 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) mechansim. The peer
delay mechansim (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.
endmenu