cdb8a3c346
When ATS is not in use, we can avoid taking the 'devices_lock' for the domain on the invalidation path by simply caching the number of ATS masters currently attached. The fiddly part is handling a concurrent ->attach() of an ATS-enabled master to a domain that is being invalidated, but we can handle this using an 'smp_mb()' to ensure that our check of the count is ordered after completion of our prior TLB invalidation. This also makes our ->attach() and ->detach() flows symmetric wrt ATS interactions. Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will@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.