This patch contains more details about the functionality
of RX copybreak.
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
XDP system has a very large footprint in the driver's overall code.
makes the whole driver's code much harder to read.
Moving XDP code to dedicated files.
This patch doesn't make any changes to the code itself and only
cut-pastes the code into ena_xdp.c and ena_xdp.h files so the change
is purely cosmetic.
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20240101190855.18739-2-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current implementation allocates page-sized rx buffers.
As traffic may consist of different types and sizes of packets,
in various cases, buffers are not fully used.
This change (Dynamic RX Buffers - DRB) uses part of the allocated rx
page needed for the incoming packet, and returns the rest of the
unused page to be used again as an rx buffer for future packets.
A threshold of 2K for unused space has been set in order to declare
whether the remainder of the page can be reused again as an rx buffer.
As a page may be reused, dma_sync_single_for_cpu() is added in order
to sync the memory to the CPU side after it was owned by the HW.
In addition, when the rx page can no longer be reused, it is being
unmapped using dma_page_unmap(), which implicitly syncs and then
unmaps the entire page. In case the kernel still handles the skbs
pointing to the previous buffers from that rx page, it may access
garbage pointers, caused by the implicit sync overwriting them.
The implicit dma sync is removed by replacing dma_page_unmap() with
dma_unmap_page_attrs() with DMA_ATTR_SKIP_CPU_SYNC flag.
The functionality is disabled for XDP traffic to avoid handling
several descriptors per packet.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20230612121448.28829-1-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
LLQ entry length is 128 bytes. Therefore the maximum header in
the entry is calculated by:
tx_max_header_size =
LLQ_ENTRY_SIZE - DESCRIPTORS_NUM_BEFORE_HEADER * 16 =
128 - 2 * 16 = 96
This patch updates the documentation so that it states the correct
max header length.
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The documentation file used to be written in markdown format but was
converted to reStructuredText (rst).
The converted file doesn't keep up with rst format requirements which
results in hard-to-read text.
This patch fixes the formatting of the file. The patch also
* Highlights and emphasizes some lines to improve readability
* Rephrases some hard-to-understand text
* Updates outdated function descriptions.
* Removes TSO description which falsely claims the driver supports it
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ena.rst documentation referred to end_start_xmit() when it should refer
to ena_start_xmit(). Fix the typo.
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The PCI vendor IDs in the documentation inaccurately describe the ENA
devices. For example, the 1d0f:ec20 can have LLQ support. The driver
loads in LLQ mode by default, and a message is printed to the kernel
ring if the mode isn't supported by the device, so the device table
isn't needed.
Also, LLQ can support various entry sizes, so the documentation is
updated to reflect that.
Interrupt moderation description is also updated to be more accurate.
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The formal name changes to "ENA_ADMIN_RSS_INDIRECTION_TABLE_CONFIG".
Indirection is the ability to reference "something" using "something else"
instead of the value itself.
Indirection table, as the name implies, is the ability to reference
CPU/Queue value using hash-to-CPU table instead of CPU/Queue itself.
This patch renames the variable keys_num, which describes the number of
words in the RSS hash key, to key_parts which makes its purpose clearer
in RSS context.
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>
Organize driver documentation by device type. Most documents
have fairly verbose yet uninformative names, so let users
first select a well defined device type, and then search for
a particular driver.
While at it rename the section from Vendor drivers to
Hardware drivers. This seems more accurate, besides people
sometimes refer to out-of-tree drivers as vendor drivers.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
David Arinzon