8a39d3e0da
The current model uses an integer ID and a fixed size struct for the
parameters of each device option.
The new model allows the device option structs to grow in size over
time. A driver may assume that changes to device option structs will
always be appended.
New device options will also generally have a
`supported_features_mask` so that the driver knows which fields within a
particular device option are enabled.
`gve_device_option.feat_mask` is changed to `required_features_mask`,
and it is a bitmask which must match the value expected by the driver.
This gives the device the ability to break backwards compatibility with
old drivers for certain features by blocking the old drivers from trying
to use the feature.
We maintain ABI compatibility with the old model for
GVE_DEV_OPT_ID_RAW_ADDRESSING in case a driver is using a device which
does not support the new model.
This patch introduces some new terminology:
RDA - Raw DMA Addressing - Buffers associated with SKBs are directly DMA
mapped and read/updated by the device.
QPL - Queue Page Lists - Driver uses bounce buffers which are DMA mapped
with the device for read/write and data is copied from/to SKBs.
Signed-off-by: Bailey Forrest <bcf@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.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.