aed6e4946e
This patch basically brings consistency with PowerNV approach to use the first freely available iommu table when the default window is removed. The pSeries iommu code convention has been that the table[0] is for the default 32 bit DMA window and the table[1] is for the 64 bit DDW. With VFs having only 1 DMA window, the default has to be removed for creating the larger DMA window. The existing code uses the table[1] for that, while marking the table[0] as NULL. This is fine as long as the host driver itself uses the device. For the VFIO user, on pSeries there is no way to skip table[0] as the VFIO subdriver uses the first freely available table. The window 0, when created as 64-bit DDW in that context would still be on table[0], as the maximum number of windows is 1. This won't have any impact for the host driver as the table is fetched from the device's iommu_table_base. Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> [mpe: Rebase and resolve conflicts] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/171923272328.1397.1817843961216868850.stgit@linux.ibm.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 reStructuredText 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.