187d292920
The midgard/bifrost GPUs need to allocate GPU heap memory which is allocated on GPU page faults and not pinned in memory. The vendor driver calls this functionality GROW_ON_GPF. This implementation assumes that BOs allocated with the PANFROST_BO_NOEXEC flag are never mmapped or exported. Both of those may actually work, but I'm unsure if there's some interaction there. It would cause the whole object to be pinned in memory which would defeat the point of this. On faults, we map in 2MB at a time in order to utilize huge pages (if enabled). Currently, once we've mapped pages in, they are only unmapped if the BO is freed. Once we add shrinker support, we can unmap pages with the shrinker. Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Robin Murphy <robin.murphy@arm.com> Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190808222200.13176-9-robh@kernel.org
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.