Robin Murphy 1817b2ccbd iommu/arm-smmu-v3: Fix big-endian CMD_SYNC writes
commit 3cd508a8c1 upstream.

When we insert the sync sequence number into the CMD_SYNC.MSIData field,
we do so in CPU-native byte order, before writing out the whole command
as explicitly little-endian dwords. Thus on big-endian systems, the SMMU
will receive and write back a byteswapped version of sync_nr, which would
be perfect if it were targeting a similarly-little-endian ITS, but since
it's actually writing back to memory being polled by the CPUs, they're
going to end up seeing the wrong thing.

Since the SMMU doesn't care what the MSIData actually contains, the
minimal-overhead solution is to simply add an extra byteswap initially,
such that it then writes back the big-endian format directly.

Cc: <stable@vger.kernel.org>
Fixes: 37de98f8f1 ("iommu/arm-smmu-v3: Use CMD_SYNC completion MSI")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09 17:38:49 +01:00
2018-12-19 19:19:50 +01:00
2019-01-09 17:38:45 +01:00
2019-01-09 17:38:45 +01:00
2018-12-29 13:37:59 +01:00

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%