c3841d020b
commit ee9d4097cc145dcaebedf6b113d17c91c21333a0 upstream. Calling the iommu_dma_sync_*_for_cpu functions during unmap can cause two copies out of the swiotlb buffer. Do the arch sync directly in __iommu_dma_unmap_swiotlb instead to avoid this. This makes the call to iommu_dma_sync_sg_for_cpu for untrusted devices in iommu_dma_unmap_sg no longer necessary, so move that invocation later in the function. Signed-off-by: David Stevens <stevensd@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/20210929023300.335969-4-stevensd@google.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Cc: Mario Limonciello <Mario.Limonciello@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
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.