The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

This code was using get_user_pages_fast(), in a "Case 2" scenario
(DMA/RDMA), using the categorization from [1]. That means that it's
time to convert the get_user_pages_fast() + put_page() calls to
pin_user_pages_fast() + unpin_user_pages() calls.

There is some helpful background in [2]: basically, this is a small
part of fixing a long-standing disconnect between pinning pages, and
file systems' use of those pages.

[1] Documentation/core-api/pin_user_pages.rst

[2] "Explicit pinning of user-space pages":
    https://lwn.net/Articles/807108/

Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: rds-devel@oss.oracle.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Westphal says:

====================
mptcp: do not block on subflow socket

This series reworks mptcp_sendmsg logic to avoid blocking on the subflow
socket.

It does so by removing the wait loop from mptcp_sendmsg_frag helper.

In order to do that, it moves prerequisites that are currently
handled in mptcp_sendmsg_frag (and cause it to wait until they are
met, e.g. frag cache refill) into the callers.

The worker can just reschedule in case no subflow socket is ready,
since it can't wait -- doing so would block other work items and
doesn't make sense anyway because we should not (re)send data
in case resources are already low.

The sendmsg path can use the existing wait logic until memory
becomes available.

Because large send requests can result in multiple mptcp_sendmsg_frag
calls from mptcp_sendmsg, we may need to restart the socket lookup in
case subflow can't accept more data or memory is low.

Doing so blocks on the mptcp socket, and existing wait handling
releases the msk lock while blocking.

Lastly, no need to use GFP_ATOMIC for extension allocation:
extend __skb_ext_alloc with gfp_t arg instead of hard-coded ATOMIC and
then relax the allocation constraints for mptcp case: those requests
occur in process context.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp calls this from the transmit side, from process context.
Allow a sleeping allocation instead of unconditional GFP_ATOMIC.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

previous patches made sure we only call into this function
when these prerequisites are met, so no need to wait on the
subflow socket anymore.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/7Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.

It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested.  mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.

This is another preparation patch that makes sure we call
mptcp_sendmsg_frag only if the page frag cache has been refilled.

Followup patch will remove the wait loop from mptcp_sendmsg_frag().

The retransmit worker doesn't need to do this refill as it won't
transmit new mptcp-level data.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.

It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested.  mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.

This is a preparation patch that makes sure we call
mptcp_sendmsg_frag only if a skb extension has been allocated.

Moreover, such allocation currently uses GFP_ATOMIC while it
could use sleeping allocation instead.

Followup patches will remove the wait loop from mptcp_sendmsg_frag()
and will allow to do a sleeping allocation for the extension.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The transmit loop continues to xmit new data until an error is returned
or all data was transmitted.

For the blocking i/o case, this means that tcp_sendpages() may block on
the subflow until more space becomes available, i.e. we end up sleeping
with the mptcp socket lock held.

Instead we should check if a different subflow is ready to be used.

This restarts the subflow sk lookup when the tx operation succeeded
and the tcp subflow can't accept more data or if tcp_sendpages
indicates -EAGAIN on a blocking mptcp socket.

In that case we also need to set the NOSPACE bit to make sure we get
notified once memory becomes available.

In case all subflows are busy, the existing logic will wait until a
subflow is ready, releasing the mptcp socket lock while doing so.

The mptcp worker already sets DONTWAIT, so no need to make changes there.

v2:
 * set NOSPACE bit
 * add a comment to clarify that mptcp-sk sndbuf limits need to
   be checked as well.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Its not enough to check for available tcp send space.

We also hold on to transmitted data for mptcp-level retransmits.
Right now we will send more and more data if the peer can ack data
at the tcp level fast enough, since that frees up tcp send buffer space.

But we also need to check that data was acked and reclaimed at the mptcp
level.

Therefore add needed check in mptcp_sendmsg, flush tcp data and
wait until more mptcp snd space becomes available if we are over the
limit.  Before we wait for more data, also make sure we start the
retransmit timer if we ran out of sndbuf space.

Otherwise there is a very small chance that we wait forever:

 * receiver is waiting for data
 * sender is blocked because mptcp socket buffer is full
 * at tcp level, all data was acked
 * mptcp-level snd_una was not updated, because last ack
   that acknowledged the last data packet carried an older
   MPTCP-ack.

Restarting the retransmit timer avoids this problem: if TCP
subflow is idle, data is retransmitted from the RTX queue.

New data will make the peer send a new, updated MPTCP-Ack.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Paolo noticed that ssk_check_wmem() has same pattern, so add/use
common helper for both places.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 'pref medium' attribute was moved in iproute2 to be near the prefix
which is where it applies versus after the last nexthop. The nexthop
tests were updated to drop the string from route checking, but it crept
in again with the compat tests.

Fixes: 4dddb5be ("selftests: net: add new testcases for nexthop API compat mode sysctl")
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alex Elder says:

====================
net: ipa: sc7180 suspend/resume

This series permits suspend/resume to work for the IPA driver
on the Qualcomm SC7180 SoC.  The IPA version on this SoC requires
interrupts to be enabled when the suspend and resume callbacks are
made, and the first patch moves away from using the noirq variants.
The second patch fixes a problem with resume that occurs because
pending interrupts were being cleared before starting a channel.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In gsi_channel_start() there is harmless-looking comment "Clear the
channel's event ring interrupt in case it's pending".  The intent
was to avoid getting spurious interrupts when first bringing up a
channel.

However we now use channel stop/start to implement suspend and
resume, and an interrupt pending at the time we resume is actually
something we don't want to ignore.

The very first time we bring up the channel we do not expect an
interrupt to be pending, and even if it were, the effect would
simply be to schedule NAPI on that channel, which would find nothing
to do, which is not a problem.

Stop clearing any pending IEOB interrupt in gsi_channel_start().
That leaves one caller of the trivial function gsi_isr_ieob_clear().
Get rid of that function and just open-code it in gsi_isr_ieob()
instead.

This fixes a problem where suspend/resume IPA v4.2 would get stuck
when resuming after a suspend.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the suspend and resume callbacks rather than suspend_noirq and
resume_noirq.  With IPA v4.2, we use the CHANNEL_STOP command to
implement a suspend, and without interrupts enabled, that command
won't complete.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Reorganize trap data

This patch set does not include any functional changes. It merely
reworks the internal storage of traps, trap groups and trap policers in
mlxsw to each use a single array.

These changes allow us to get rid of the multiple arrays we currently
have for traps, which make the trap data easier to validate and extend
with more per-trap information in the future. It will also allow us to
more easily add per-ASIC traps in future submissions.

Last two patches include minor changes to devlink-trap selftests.

Tested with existing devlink-trap selftests.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

It can be derived dynamically from the trap's name, so drop it.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

One blank line is enough.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Each trap registered with devlink is mapped to one or more Rx listeners.
These listeners allow the switch driver (e.g., mlxsw_spectrum) to
register a function that is called when a packet is received (trapped)
for a specific reason.

Currently, three arrays are used to describe the mapping between the
logical devlink traps and the Rx listeners.

Instead, get rid of these arrays and store all the information in one
array that is easier to validate and extend with more per-trap
information.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use one array to store all the information about all the trap groups
instead of hard coding it in code. This will be used in future patches
to disable certain functionality (e.g., policer binding) on a trap group
basis.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of maintaining an array of policers and a linked list, only
maintain an array.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

'struct mlxsw_sp_trap_policer_item' is only used in one file, so move it
there.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

After having switched to devm_mdiobus_register() also this remaining
call to mdiobus_unregister() can be removed.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
ethtool: set_channels: add a few more checks

There seems to be a few more things we can check in the core before
we call drivers' ethtool_ops->set_channels. Adding the checks to
the core simplifies the drivers. This set only includes changes
to the NFP driver as an example.

There is a small risk in the first patch that someone actually
purposefully accepts a strange configuration without RX or TX
channels, but I couldn't find such a driver in the tree.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Don't call drivers if nothing changed. Netlink code already
contains this logic.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Core will now perform this check.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Having a channel config with no ability to RX or TX traffic is
clearly wrong. Check for this in the core so the drivers don't
have to.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not
sending 64-bit data-sequence numbers. The 64-bit DSN is only there for
extreme scenarios when a very high throughput subflow is combined with a
long-RTT subflow such that the high-throughput subflow wraps around the
32-bit sequence number space within an RTT of the high-RTT subflow.

It is thus a rare scenario and we should try to use the 32-bit DATA_ACK
instead as long as possible. It allows to reduce the TCP-option overhead
by 4 bytes, thus makes space for an additional SACK-block. It also makes
tcpdumps much easier to read when the DSN and DATA_ACK are both either
32 or 64-bit.
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

The goal is to be able to inherit the initial devconf parameters from the
current netns, ie the netns where this new netns has been created.

This is useful in a containers environment where /proc/sys is read only.
For example, if a pod is created with specifics devconf parameters and has
the capability to create netns, the user expects to get the same parameters
than his 'init_net', which is not the real init_net in this case.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add driver level bulking to the XDP_TX action.

An array of frame descriptors is held for each Tx frame queue and
populated accordingly when the action returned by the XDP program is
XDP_TX. The frames will be actually enqueued only when the array is
filled. At the end of the NAPI cycle a flush on the queued frames is
performed in order to enqueue the remaining FDs.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch makes checkpatch happy for tabs
Signed-off-by: Kevin Lo <kevlo@kevlo.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2020-05-15

mlx5 core and mlx5e (netdev) updates:

1) Two fixes for release all FW pages support.
2) Improvement in calculating the send queue stop room on tx
3) Flow steering auto-groups creation improvements
4) TC offload fix for Connection tracking with NAT action
5) IPoIB support for self looback to allow communication between ipoib
pkey child interfaces on the same host.
6) DCBNL cleanup to avoid #ifdef DCBNL all over the main mlx5e code
7) Small and trivial code cleanup
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When building with Clang:

In file included from drivers/net/ethernet/ti/am65-cpsw-ethtool.c:15:
drivers/net/ethernet/ti/am65-cpts.h:58:12: warning: unused function
'am65_cpts_ns_gettime' [-Wunused-function]
static s64 am65_cpts_ns_gettime(struct am65_cpts *cpts)
           ^
drivers/net/ethernet/ti/am65-cpts.h:63:12: warning: unused function
'am65_cpts_estf_enable' [-Wunused-function]
static int am65_cpts_estf_enable(struct am65_cpts *cpts,
           ^
drivers/net/ethernet/ti/am65-cpts.h:69:13: warning: unused function
'am65_cpts_estf_disable' [-Wunused-function]
static void am65_cpts_estf_disable(struct am65_cpts *cpts, int idx)
            ^
3 warnings generated.

These functions need to be marked as inline, which adds __maybe_unused,
to avoid these warnings, which is the pattern for stub functions.

Fixes: ec008fa2 ("ethernet: ti: am65-cpts: add routines to support taprio offload")
Link: https://github.com/ClangBuiltLinux/linux/issues/1026Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Take DCBNL-related definitions out of the common en.h header,
Use a dedicated header file for exposing them.
Some need not to be exposed, use them locally in the .c file.
Use stubs to eliminate use of CONFIG_MLX5_CORE_EN_DCB in the
generic control flows.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Currently, different formulas are used to estimate the space that may be
taken by WQEs in the SQ during a single packet transmit. This space is
called stop room, and it's checked in the end of packet transmit to find
out if the next packet could overflow the SQ. If it could, the driver
tells the kernel to stop sending next packets.

Many factors affect the stop room:

1. Padding with NOPs to avoid WQEs spanning over page boundaries.

2. Enabled and disabled offloads (TLS, upcoming MPWQE).

3. The maximum size of a WQE.

The padding is performed before every WQE if it doesn't fit the current
page.

The current formula assumes that only one padding will be required per
packet, and it doesn't take into account that the WQEs posted during the
transmission of a single packet might exceed the page size in very rare
circumstances. For example, to hit this condition with 4096-byte pages,
TLS offload will have to interrupt an almost-full MPWQE session, be in
the resync flow and try to transmit a near to maximum amount of data.

To avoid SQ overflows in such rare cases after MPWQE is added, this
patch introduces a more robust formula to estimate the stop room. The
new formula uses the fact that a WQE of size X will not require more
than X-1 WQEBBs of padding. More exact estimations are possible, but
they result in much more complex and error-prone code for little gain.

Before this patch, the TLS stop room included space for both INNOVA and
ConnectX TLS offloads that couldn't run at the same time anyway, so this
patch accounts only for the active one.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

After enabled loopback packets for IPoIB, we need to drop these packets
that this HCA has replicated and came back to the same interface that
sent them.

Fixes: 4c6c615e ("net/mlx5e: IPoIB, Add PKEY child interface nic profile")
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Enable loopback of unicast and multicast traffic for IPoIB enhanced
mode.
This will allow interfaces with the same pkey to communicate between
them e.g cloned interfaces that located in different namespaces.
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

It could be a chain of rules will do action CT again after CT NAT
Before this fix matching will break as we get into the CT table
after NAT changes and not CT NAT.
Fix this by adding pre ct and pre ct nat tables to skip ct/ct_nat
tables and go straight to post_ct table if ct/nat was already done.
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Move mlx5_read_internal_timer() into lib/clock.c file as it is being
used there. As such, make this function a static one.

In addition, rearrange headers include to support function move.
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Currently, if one thread tries to add an entry to an autogrouped table
with no free matching group, while another thread is in the process of
creating a new matching autogroup, it doesn't wait for the new group
creation, and creates an unnecessary new autogroup.

Instead of skipping inactive, wait on the write lock of those groups.
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

mlx5_unload_one() is done with cleanup = true only once.

So instead of doing health wq drain inside the if(), directly do
during PCI device removal.
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>