mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 02:21:52 +09:00
21d5d27c04
Currently the Intel IOMMU uses the default dma_[un]map_resource() implementations does nothing and simply returns the physical address unmodified. However, this doesn't create the IOVA entries necessary for addresses mapped this way to work when the IOMMU is enabled. Thus, when the IOMMU is enabled, drivers relying on dma_map_resource() will trigger DMAR errors. We see this when running ntb_transport with the IOMMU enabled, DMA, and switchtec hardware. The implementation for intel_map_resource() is nearly identical to intel_map_page(), we just have to re-create __intel_map_single(). dma_unmap_resource() uses intel_unmap_page() directly as the functions are identical. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Joerg Roedel <joro@8bytes.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Joerg Roedel <jroedel@suse.de>
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.