61b2143ac9
[ Upstream commit 61192a9d8a6367ae1b8234876941b037910a2459 ]
The Tegra SYSRAM contains regions access to which is restricted to
certain hardware blocks on the system, and speculative accesses to
those will cause issues.
Patch 'misc: sram: Only map reserved areas in Tegra SYSRAM' attempted
to resolve this by only mapping the regions specified in the device
tree on the assumption that there are no such restricted areas within
the 64K-aligned area of memory that contains the memory we wish to map.
Turns out this assumption is wrong, as there are such areas above the
4K pages described in the device trees. As such, we need to use the
bigger hammer that is no-memory-wc, which causes the memory to be
mapped as Device memory to which speculative accesses are disallowed.
As such, the previous patch in the series,
'firmware: tegra: bpmp: do only aligned access to IPC memory area',
is required with this patch to make the BPMP driver only issue aligned
memory accesses as those are also required with Device memory.
Fixes: fec29bf04994 ("misc: sram: Only map reserved areas in Tegra SYSRAM")
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@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.