a999933db9
mips_swiotlb_ops differs from the generic swiotlb_dma_ops only in that
it contains a mb() barrier after each operations that maps or syncs
dma memory to the device.
The dma operations are defined to not be memory barriers, but instead
the write* operations to kick the DMA off are supposed to contain them.
For mips this handled by war_io_reorder_wmb(), which evaluates to the
stronger wmb() instead of the pure compiler barrier barrier() for
just those platforms that use swiotlb, so I think we are covered
properly.
[paul.burton@mips.com:
- Include linux/swiotlb.h to fix build failures for configs with
CONFIG_SWIOTLB=y.]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20038/
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.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.
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.