Commit Graph

6 Commits

Author SHA1 Message Date
Paul Burton
262e4c3893
FDDI: defza: Include linux/io-64-nonatomic-lo-hi.h
Currently arch/mips/include/asm/io.h provides 64b memory accessor
functions such as readq & writeq even on MIPS32 platforms where those
accessors cannot actually perform a 64b memory access. They instead
BUG(). This is unfortunate for drivers which either #ifdef on the
presence of these accessors, or can function with non-atomic
implementations of them found in either linux/io-64-nonatomic-lo-hi.h or
linux/io-64-nonatomic-hi-lo.h. As such we're preparing to remove the
definitions of these 64b accessor functions for MIPS32 kernels.

In preparation for this, include linux/io-64-nonatomic-lo-hi.h in
defza.c in order to provide a non-atomic implementation of the
readq_relaxed & writeq_relaxed functions that are used by this code. In
practice this will have no runtime effect, since use of the 64b accessor
functions is conditional upon sizeof(unsigned long) == 8, ie. upon
CONFIG_64BIT=y. This means the calls to these non-atomic readq & writeq
implementations will be optimized out anyway, but we need their
definitions to keep the compiler happy.

For 64bit kernels using this code this change should also have no effect
because asm/io.h will continue to provide the definitions of
readq_relaxed & writeq_relaxed, which linux/io-64-nonatomic-lo-hi.h
checks for before defining itself.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Maciej W. Rozycki <macro@linux-mips.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Serge Semin <Sergey.Semin@t-platforms.ru>
Cc: netdev@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
2019-06-24 14:14:49 -07:00
Maciej W. Rozycki
8f5365ebf7 FDDI: defza: Make the driver version string constant
The driver version string is obviously not meant to be changed at run
time, so mark it `const'.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-07 21:53:31 -08:00
Maciej W. Rozycki
04453b6b24 FDDI: defza: Move SMT Tx data buffer declaration next to its skb
Move the temporary data buffer used when tapping into the SMT Tx queue
from the outer function level into the conditional block it's actually
used in and its containing skb is also declared, making the structure of
code better.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-07 21:53:31 -08:00
Maciej W. Rozycki
96ed82cc1f FDDI: defza: Fix SPDX annotation
The SPDX annotation for this driver does not match the license text,
which specifies GNU GPL 2 or later.  Make the two match by correcting
the SPDX tag.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-07 21:53:30 -08:00
Maciej W. Rozycki
9f9a742db4 FDDI: defza: Support capturing outgoing SMT traffic
DEC FDDIcontroller 700 (DEFZA) uses a Tx/Rx queue pair to communicate
SMT frames with adapter's firmware.  Any SMT frame received from the RMC
via the Rx queue is queued back by the driver to the SMT Rx queue for
the firmware to process.  Similarly the firmware uses the SMT Tx queue
to supply the driver with SMT frames which are queued back to the Tx
queue for the RMC to send to the ring.

When a network tap is attached to an FDDI interface handled by `defza'
any incoming SMT frames captured are queued to our usual processing of
network data received, which in turn delivers them to any listening
taps.

However the outgoing SMT frames produced by the firmware bypass our
network protocol stack and are therefore not delivered to taps.  This in
turn means that taps are missing a part of network traffic sent by the
adapter, which may make it more difficult to track down network problems
or do general traffic analysis.

Call `dev_queue_xmit_nit' then in the SMT Tx path, having checked that
a network tap is attached, with a newly-created `dev_nit_active' helper
wrapping the usual condition used in the transmit path.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15 21:46:06 -07:00
Maciej W. Rozycki
61414f5ec9 FDDI: defza: Add support for DEC FDDIcontroller 700 TURBOchannel adapter
Add support for the DEC FDDIcontroller 700 (DEFZA), Digital Equipment
Corporation's first-generation FDDI network interface adapter, made for
TURBOchannel and based on a discrete version of what eventually became
Motorola's widely used CAMEL chipset.

The CAMEL chipset is present for example in the DEC FDDIcontroller
TURBOchannel, EISA and PCI adapters (DEFTA/DEFEA/DEFPA) that we support
with the `defxx' driver, however the host bus interface logic and the
firmware API are different in the DEFZA and hence a separate driver is
required.

There isn't much to say about the driver except that it works, but there
is one peculiarity to mention.  The adapter implements two Tx/Rx queue
pairs.

Of these one pair is the usual network Tx/Rx queue pair, in this case
used by the adapter to exchange frames with the ring, via the RMC (Ring
Memory Controller) chip.  The Tx queue is handled directly by the RMC
chip and resides in onboard packet memory.  The Rx queue is maintained
via DMA in host memory by adapter's firmware copying received data
stored by the RMC in onboard packet memory.

The other pair is used to communicate SMT frames with adapter's
firmware.  Any SMT frame received from the RMC via the Rx queue must be
queued back by the driver to the SMT Rx queue for the firmware to
process.  Similarly the firmware uses the SMT Tx queue to supply the
driver with SMT frames that must be queued back to the Tx queue for the
RMC to send to the ring.

This solution was chosen because the designers ran out of PCB space and
could not squeeze in more logic onto the board that would be required to
handle this SMT frame traffic without the need to involve the driver, as
with the later DEFTA/DEFEA/DEFPA adapters.

Finally the driver does some Frame Control byte decoding, so to avoid
magic numbers some macros are added to <linux/if_fddi.h>.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15 21:46:06 -07:00