84eac0c659
We have problems of tgl not seeing a valid pte entry when iommu is enabled. Add heavy handed flushing of entry modification by flushing the cpu, cacheline and then wcb. This forces the pte out to main memory past this point regarless of promises of coherency. This is an evolution of an experimental patch from Chris Wilson of adding wmb for coherent partners, by adding a clflush to force the cache->memory step. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1840 Testcase: igt/gem_exec_fence/parallel Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20200511160803.15407-1-mika.kuoppala@linux.intel.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.