8eb6859547
The secure firmware keeps some SID override registers set as passthrough in order to allow devices such as the display controller to operate with no knowledge of SMMU translations until an operating system driver takes over. This is needed in order to seamlessly transition from the firmware framebuffer to the OS framebuffer. Upon successfully attaching a device to the SMMU and in the process creating identity mappings for memory regions that are being accessed, the Tegra implementation will call into the memory controller driver to program the override SIDs appropriately. Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20210603164632.1000458-6-thierry.reding@gmail.com Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
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.