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Alexey Kardashevskiy
7559d3d295
By default a pseries guest supports a H_PUT_TCE hypercall which maps
a single IOMMU page in a DMA window. Additionally the hypervisor may
support H_PUT_TCE_INDIRECT/H_STUFF_TCE which update multiple TCEs at once;
this is advertised via the device tree /rtas/ibm,hypertas-functions
property which Linux converts to FW_FEATURE_MULTITCE.
FW_FEATURE_MULTITCE is checked when dma_iommu_ops is used; however
the code managing the huge DMA window (DDW) ignores it and calls
H_PUT_TCE_INDIRECT even if it is explicitly disabled via
the "multitce=off" kernel command line parameter.
This adds FW_FEATURE_MULTITCE checking to the DDW code path.
This changes tce_build_pSeriesLP to take liobn and page size as
the huge window does not have iommu_table descriptor which usually
the place to store these numbers.
Fixes: 4e8b0cf46b ("powerpc/pseries: Add support for dynamic dma windows")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191216041924.42318-3-aik@ozlabs.ru
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.