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84f5a7b67b
We have several SCM calls that require passing buffers to the TrustZone on top of the SMC core which allocates memory for calls that require more than 4 arguments. Currently every user does their own thing which leads to code duplication. Many users call dma_alloc_coherent() for every call which is terribly unperformant (speed- and size-wise). Provide a set of library functions for creating and managing pools of memory which is suitable for sharing with the TrustZone, that is: page-aligned, contiguous and non-cachable as well as provides a way of mapping of kernel virtual addresses to physical space. Make the allocator ready for extending with additional modes of operation which will allow us to support the SHM bridge safety mechanism once all users convert. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Andrew Halaney <ahalaney@redhat.com> Tested-by: Andrew Halaney <ahalaney@redhat.com> # sc8280xp-lenovo-thinkpad-x13s Tested-by: Deepti Jaggi <quic_djaggi@quicinc.com> #sa8775p-ride Reviewed-by: Elliot Berman <quic_eberman@quicinc.com> Link: https://lore.kernel.org/r/20240527-shm-bridge-v10-2-ce7afaa58d3a@linaro.org Signed-off-by: Bjorn Andersson <andersson@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 reStructuredText 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.