The verdict returned from ena_xdp_execute() is used to determine the
fate of the RX buffer's page. In case of XDP Redirect/TX error the
verdict should be set to XDP_ABORTED, otherwise the page won't be freed.

Fixes: a318c70ad152 ("net: ena: introduce XDP redirect implementation")
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Introduce xdp_prepare_buff utility routine to initialize per-descriptor
xdp_buff fields (e.g. xdp_buff pointers). Rely on xdp_prepare_buff() in
all XDP capable drivers.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Acked-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/bpf/45f46f12295972a97da8ca01990b3e71501e9d89.1608670965.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Introduce xdp_init_buff utility routine to initialize xdp_buff fields
const over NAPI iterations (e.g. frame_sz or rxq pointer). Rely on
xdp_init_buff in all XDP capable drivers.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Acked-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/bpf/7f8329b6da1434dc2b05a77f2e800b29628a8913.1608670965.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

This patch implements the ndo_xdp_xmit() net_device function which is
called when a packet is redirected to this driver using an
XDP_REDIRECT directive.

The function receives an array of xdp frames that it needs to xmit.
The TX queues that are used to xmit these frames are the XDP
queues used by the XDP_TX flow. Therefore a lock is added to synchronize
both flows (XDP_TX and XDP_REDIRECT).

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

XDP subsystem has a function to free XDP frames and their associated
pages. Using this function would help the driver's XDP implementation to
adjust to new changes in the XDP subsystem in the kernel (e.g.
introduction of XDP MB).

Also, remove 'xdp_rx_page' field from ena_tx_buffer struct since it is
no longer used.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch adds a partial support for the XDP_REDIRECT directive which
instructs the driver to pass the packet to an interface specified by the
program. The directive is passed to the driver by calling bpf_redirect()
or bpf_redirect_map() functions from the eBPF program.

To lay the ground for integration with the existing XDP TX
implementation the patch removes the redundant page ref count increase
in ena_xdp_xmit_frame() and then decrease in ena_clean_rx_irq(). Instead
it only DMA unmaps descriptors for which XDP TX or REDIRECT directive
was received.

The XDP Redirect support is still missing .ndo_xdp_xmit function
implementation, which allows to redirect packet to an ENA interface,
which would be added in a later patch.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Rename the ena_xdp_xmit_buff() function to ena_xdp_xmit_frame() and pass
it an xdp_frame struct instead of xdp_buff.
This change lays the ground for XDP redirect implementation which uses
xdp_frames when 'xmit'ing packets.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Introduce ena_increase_stat() function to increase statistics by a
certain number.
The function includes the
    - lock aquire (on 32bit machines)
    - stat increase
    - lock release (on 32bit machines)

line sequence that is ubiquitous across the driver.

The function increases a single stat at a time and several stats which
are increased together weren't put into a function to avoid
calling the function several times for each stat which looks bad and
might decrease performance.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This commit fixes two nits, but it does not generate any change to binary
because of the optimization of gcc.

  - use `count` instead of `channels->combined_count`
  - change return type from `int` to `bool`

Also add spaces and change macro order in OR assignment to make the code
easier to read.

Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>