Real devices may support scatter gather(SG), so enable SG on rmnet
devices to use GSO. GSO reduces CPU cycles by 20% for a rate of
146Mpbs for a single stream TCP connection.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TX checksum offload applies to TCP / UDP packets which are not
fragmented using the MAPv4 checksum trailer. The following needs to be
done to have checksum computed in hardware -
1. Set the checksum start offset and inset offset.
2. Set the csum_enabled bit
3. Compute and set 1's complement of partial checksum field in
transport header.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When using the MAPv4 packet format in conjunction with MAP commands,
a dummy DL checksum trailer will be appended to the packet. Before
this packet is sent out as an ACK, the DL checksum trailer needs to be
removed.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When using the MAPv4 packet format, receive checksum offload can be
enabled in hardware. The checksum computation over pseudo header is
not offloaded but the rest of the checksum computation over
the payload is offloaded. This applies only for TCP / UDP packets
which are not fragmented.
rmnet validates the TCP/UDP checksum for the packet using the checksum
from the checksum trailer added to the packet by hardware. The
validation performed is as following -
1. Perform 1's complement over the checksum value from the trailer
2. Compute 1's complement checksum over IPv4 / IPv6 header and
subtracts it from the value from step 1
3. Computes 1's complement checksum over IPv4 / IPv6 pseudo header and
adds it to the value from step 2
4. Subtracts the checksum value from the TCP / UDP header from the
value from step 3.
5. Compares the value from step 4 to the checksum value from the
TCP / UDP header.
6. If the comparison in step 5 succeeds, CHECKSUM_UNNECESSARY is set
and the packet is passed on to network stack. If there is a
failure, then the packet is passed on as such without modifying
the ip_summed field.
The checksum field is also checked for UDP checksum 0 as per RFC 768
and for unexpected TCP checksum of 0.
If checksum offload is disabled when using MAPv4 packet format in
receive path, the packet is queued as is to network stack without
the validations above.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MAPv4 packet format adds support for RX / TX checksum offload.
For a bi-directional UDP stream at a rate of 570 / 146 Mbps, roughly
10% CPU cycles are saved.
For receive path, there is a checksum trailer appended to the end of
the MAP packet. The valid field indicates if hardware has computed
the checksum. csum_start_offset indicates the offset from the start
of the IP header from which hardware has computed checksum.
csum_length is the number of bytes over which the checksum was
computed and the resulting value is csum_value.
In the transmit path, a header is appended between the end of the MAP
header and the start of the IP packet. csum_start_offset is the offset
in bytes from which hardware will compute the checksum if the
csum_enabled bit is set. udp_ip4_ind indicates if the checksum
value of 0 is valid or not. csum_insert_offset is the offset from the
csum_start_offset where hardware will insert the computed checksum.
The use of this additional packet format for checksum offload is
explained in subsequent patches.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The real device over which the rmnet devices are installed also
aggregate multiple IP packets and sends them as a single large
aggregate frame to the hardware. This causes degraded throughput
for TCP TX due to bufferbloat.
To overcome this problem, pacing shift value of 8 is set using the
sk_pacing_shift_update() helper. This value was determined based
on experiments with a single stream TCP TX using iperf for a
duration of 30s.
Pacing shift | Observed data rate (Mbps)
10 | 9
9 | 140
8 | 146 (Max link rate)
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done so that we can use this field for both ingress and
egress flags.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
rmnet_map_demultiplex() is only declared but not defined anywhere,
so remove it.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
rmnet devices cannot have a mux id of 255. This is validated when
assigning the mux id to the rmnet devices. As a result, checking for
mux id 255 does not apply in egress path.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We already check the headroom once in rmnet_map_egress_handler(),
so this is not needed.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an option to configure the mux id, aggregation and commad feature
for existing rmnet devices. Implement the changelink netlink
operation for this.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an option to configure the rmnet aggregation and command features
on device creation. This is achieved by using the vlan flags option.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support to send and receive packets over ethernet.
An example of usage is testing the data path on UML. This can be
achieved by setting up two UML instances in multicast mode and
associating rmnet over the UML ethernet device.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Upon de-multiplexing data from one real dev, the packets can be sent
to an unique rmnet device for a given mux id.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Multiplexing is always enabled when transmiting from a rmnet device,
so remove the redundant egress macros. De-multiplexing is always
enabled when receiving packets from a rmnet device, so remove those
ingress macros.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only the success and consumed entries were actually in use.
Use standard error codes instead.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the rmnet device creation fails in the newlink either while
registering with the physical device or after subsequent
operations, the rmnet endpoint information is never freed.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a skb in transmit path does not have sufficient headroom to add
the map header, the skb is not sent out and is never freed.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add gro_cells so that rmnet devices can call gro_cells_receive
instead of netif_receive_skb.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement 64 bit per cpu stats.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rmnet device needs to assigned for all packets in the
deaggregation path based on the mux id, so the check is not needed.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since packet is always consumed by rmnet_rx_handler(), we always
return RX_HANDLER_CONSUMED. There is no need to pass on this
value through multiple functions.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support to bridge two devices which can send multiplexing and
aggregation (MAP) data. This is done only when the data itself is
not going to be consumed in the stack but is being passed on to a
different endpoint. This is mainly used for testing.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than using a static array, use a hlist to store the muxed
endpoints and use the mux id to query the rmnet_device.
This is useful as usually very few mux ids are used.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rmnet_devices information is already stored in muxed_ep, so
storing this in rmnet_devices[] again is redundant.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The end point is set twice in the local_ep as well as the mux_id and
the real_dev in the rmnet private structure. Remove the local_ep.
While these elements are equivalent, rmnet_endpoint will be
used only as part of the rmnet_port for muxed scenarios in VND mode.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mode information on the real device makes it easier to route packets
to rmnet device or bridged device based on the configuration.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most of these constants were used in the initial patchset where
custom netlink configuration was used and hence are no longer relevant.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This will be rewritten in the following patches.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add extack arg to netdev_upper_dev_link and netdev_master_upper_dev_link
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a typo here so we accidentally free "skb" instead of "skbn".
It leads to a double free and a leak. After discussing with Subash,
it's better to just move the check before the allocation and avoid the
need to free.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make it similar to drivers like ipvlan / macvlan so it is easier to read.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This makes it easier to find out the parent dev.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Data format can be directly set from rmnet_newlink() since the
rmnet real dev info is already available.
Since __rmnet_get_real_dev_info() is no longer used in rmnet_config.c
after removal of those functions, move content to
rmnet_get_real_dev_info().
__rmnet_set_endpoint_config() is collapsed into
rmnet_set_endpoint_config() since only mux_id was being set additionally
within it. Remove an unnecessary mux_id check.
Set the mux_id for the rmnet_dev within rmnet_vnd_newlink() itself.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current log is not very useful as it does not log the device
name since it it is prior to registration -
(unnamed net_device) (uninitialized): Setting up device
Modify to log after the device registration -
rmnet1: rmnet dev created
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was used only in the original patch series where the IOCTLs were
present and is no longer in use.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rmnet_rtnl_validate() was checking for upto mux_id 254, however the
rmnet_devices devices could hold upto 32 entries only. Fix this by
increasing the size of the rmnet_devices.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
priv is being assigned but is never used, so remove it.
Cleans up clang build warning:
"warning: Value stored to 'priv' is never read"
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
RmNet driver provides a transport agnostic MAP (multiplexing and
aggregation protocol) support in embedded module. Module provides
virtual network devices which can be attached to any IP-mode
physical device. This will be used to provide all MAP functionality
on future hardware in a single consistent location.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
