657d42cf5d
A future change will convert the DMA API implementation from the architecture specific arch/s390/pci/pci_dma.c to using the common code drivers/iommu/dma-iommu.c which the utilizes the same IOMMU hardware through the s390-iommu driver. Unlike the s390 specific DMA API this requires devices to correctly set the coherent mask to be allowed to use IOVAs >2^32 in dma_alloc_coherent(). This was however not done for ISM devices. ISM requires such addresses since currently the DMA aperture for PCI devices starts at 2^32 and all calls to dma_alloc_coherent() would thus fail. Link: https://lore.kernel.org/all/20230310-dma_iommu-v9-1-65bb8edd2beb@linux.ibm.com/ Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Link: https://lore.kernel.org/r/20230524075411.3734141-1-schnelle@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.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 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.