net: ena: Reduce lines with longer column width boundary

This patch reduces some of the lines by removing newlines
where more variables or print strings can be pushed back
to the previous line while still adhering to the styling
guidelines.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: ena: Remove CQ tail pointer update

The functionality was added to allow the drivers to create an
SQ and CQ of different sizes.
When the RX/TX SQ and CQ have the same size, such update isn't
necessary as the device can safely assume it doesn't override
unprocessed completions. However, if the SQ is larger than the CQ,
the device might "have" more completions it wants to update about
than there's room in the CQ.

There's no support for different SQ and CQ sizes, therefore,
removing the API and its usage.

'____cacheline_aligned' compiler attribute was added to
'struct ena_com_io_cq' to ensure that the removal of the
'cq_head_db_reg' field doesn't change the cache-line layout
of this struct.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: ena: Add support to changing tx_push_buf_len

The ENA driver allows for two distinct values for the number of bytes
of the packet's payload that can be written directly to the device.

For a value of 224 the driver turns on Large LLQ Header mode in which
the first 224 of the packet's payload are written to the LLQ.

Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ena: add device distinct log prefix to files

ENA logs are adjusted to display the full ENA representation to
distinct each ENA device in case of multiple interfaces.
Using netdev_err/warn and dev_info functions for logging provides
uniform printing with clear distinction of the device and interface.

This patch changes all printing in ena_com files to use netev_* logging
functions except for messages of info level. Log functions of that level
would be printed with dev_info because of the early stage they are
called in when net_device struct isn't yet registered.

To allow using netdev_* functions in all ena_com functions, a pointer to
the net_device was added to ena_com_dev struct.

The patch also adds some log messages to make driver debugging easier.

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

net: ena: Capitalize all log strings and improve code readability

Capitalize all log strings printed by the ena driver to make their
format uniform across it.

Also fix indentation, spelling mistakes and comments to improve code
readability. This also includes adding comments to macros/enums whose
purpose might be difficult to understand.
Separate some code into functions to make it easier to understand the
purpose of these lines.

Signed-off-by: Amit Bernstein <amitbern@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: Change license into format to SPDX in all files

All ena files should now use SPDX format in their license string. This
doesn't change the license of the files, but rather states the same
license in fewer words.

Also update the license years in some of the files.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: support new LLQ acceleration mode

New devices add a new hardware acceleration engine, which adds some
restrictions to the driver.
Metadata descriptor must be present for each packet and the maximum
burst size between two doorbells is now limited to a number
advertised by the device.

This patch adds:
1. A handshake protocol between the driver and the device, so the
device will enable the accelerated queues only when both sides
support it.

2. The driver support for the new acceleration engine:
2.1. Send metadata descriptor for each Tx packet.
2.2. Limit the number of packets sent between doorbells.(*)

(*) A previous driver implementation of this feature was comitted in
commit 05d62ca218f8 ("net: ena: add handling of llq max tx burst size")
however the design of the interface between the driver and device
changed since then. This change is reflected in this commit.

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: rename ena_com_free_desc to make API more uniform

Rename ena_com_free_desc to ena_com_free_q_entries to match
the LLQ mode.

In non-LLQ mode, an entry in an IO ring corresponds to a
a descriptor. In LLQ mode an entry may correspond to several
descriptors (per LLQ definition).

Signed-off-by: Igor Chauskin <igorch@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: add support for the rx offset feature

Newer ENA devices can write data to rx buffers with an offset
from the beginning of the buffer.

This commit adds support for this feature in the driver.

Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: optimise calculations for CQ doorbell

This patch initially checks if CQ doorbell
is needed before proceeding with the calculations.

Signed-off-by: Igor Chauskin <igorch@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: add handling of llq max tx burst size

There is a maximum TX burst size that the ENA device can handle.
It is exposed by the device to the driver and the driver
needs to comply with it to avoid bugs.

In this commit we:
1. Add ena_com_is_doorbell_needed(), which calculates the number of
llq entries that will be used to hold a packet, and will return
true if they exceed the number of allowed entries in a burst.
If the function returns true, a doorbell needs to be invoked
to send this packet in the next burst.

2. Follow the available entries in the current burst:
- Every doorbell a new burst begins
- With each write of an llq entry, the available entries in the
current burst are decreased by 1.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: use CSUM_CHECKED device indication to report skb's checksum status

Set skb->ip_summed to the correct value as reported by the device.
Add counter for the case where rx csum offload is enabled but
device didn't check it.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: add functions for handling Low Latency Queues in ena_com

This patch introduces APIs for detection, initialization, configuration
and actual usage of low latency queues(LLQ). It extends transmit API with
creation of LLQ descriptors in device memory (which include host buffers
descriptors as well as packet header)

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: minor performance improvement

Reduce fastpath overhead by making ena_com_tx_comp_req_id_get() inline.
Also move it to ena_eth_com.h file with its dependency function
ena_com_cq_inc_head().

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: fix incorrect usage of memory barriers

Added memory barriers where they were missing to support multiple
architectures, and removed redundant ones.

As part of removing the redundant memory barriers and improving
performance, we moved to more relaxed versions of memory barriers,
as well as to the more relaxed version of writel - writel_relaxed,
while maintaining correctness.

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: Eliminate duplicate barriers on weakly-ordered archs

Code includes barrier() followed by writel(). writel() already has a
barrier on some architectures like arm64.

This ends up CPU observing two barriers back to back before executing the
register write.

Create a new wrapper function with relaxed write operator. Use the new
wrapper when a write is following a barrier().

Since code already has an explicit barrier call, changing writel() to
writel_relaxed() and adding mmiowb() for ordering protection.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: add detection and recovery mechanism for handling missed/misrouted MSI-X

A mechanism for detection of stuck Rx/Tx rings due to missed or
misrouted interrupts.
Check if there are unhandled completion descriptors before the first
MSI-X interrupt arrived.
The check is per queue and per interrupt vector.
Once such condition is detected, driver and device reset is scheduled.

Signed-off-by: Netanel Belgazal <netanel@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)

This is a driver for the ENA family of networking devices.

Signed-off-by: Netanel Belgazal <netanel@annapurnalabs.com>
Signed-off-by: David S. Miller <davem@davemloft.net>