1948d28db6
Currently code allocates non-scanout BOs from SHMEM and those objects are accessible to userspace by mmap(). However, on devices with no DMM (like OMAP3), the same objects are not accessible by kernel drivers that want to render to them as code refuses to export them. In turn this means that on devices with no DMM, all buffers must be allocated as scanout, otherwise only CPU can access them. On those devices, scanout buffers are allocated from CMA, making those allocations highly unreliable. Fix that by implementing functionality to export SHMEM backed buffers on devices with no DMM. This makes CMA memory only being used when needed, instead for every buffer that has to be off-CPU rendered. Tested on Motorola Droid4 and Nokia N900 Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Link: https://patchwork.freedesktop.org/patch/msgid/1642587791-13222-3-git-send-email-ivo.g.dimitrov.75@gmail.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.