48276c08cf
This patch adds the support for receiving packets via the AF_XDP zero-copy mechanism in the dpaa2-eth driver. The support is available only on the LX2160A SoC and variants because we are relying on the HW capability to associate a buffer pool to a specific queue (QDBIN), only available on newer WRIOP versions. On the control path, the dpaa2_xsk_enable_pool() function is responsible to allocate a buffer pool (BP), setup this new BP to be used only on the requested queue and change the consume function to point to the XSK ZC one. We are forced to call dev_close() in order to change the queue to buffer pool association (dpaa2_xsk_set_bp_per_qdbin) . This also works in our favor since at dev_close() the buffer pools will be drained and at the later dev_open() call they will be again seeded, this time with buffers allocated from the XSK pool if needed. On the data path, a new software annotation type is defined to be used only for the XSK scenarios. This will enable us to pass keep necessary information about a packet buffer between the moment in which it was seeded and when it's received by the driver. In the XSK case, we are keeping the associated xdp_buff. Depending on the action returned by the BPF program, we will do the following: - XDP_PASS: copy the contents of the packet into a brand new skb, recycle the initial buffer. - XDP_TX: just enqueue the same frame descriptor back into the Tx path, the buffer will get automatically released into the initial BP. - XDP_REDIRECT: call xdp_do_redirect() and exit. Signed-off-by: Robert-Ionut Alexa <robert-ionut.alexa@nxp.com> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.