mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-03-15 04:06:28 -04:00
42ee3cae0e
Error handling of the dma_map_single and dma_map_page APIs is a little problematic at the moment, in that we use different encodings in the returned dma_addr_t to indicate an error. That means we require an additional indirect call to figure out if a dma mapping call returned an error, and a lot of boilerplate code to implement these semantics. Instead return the maximum addressable value as the error. As long as we don't allow mapping single-byte ranges with single-byte alignment this value can never be a valid return. Additionaly if drivers do not check the return value from the dma_map* routines this values means they will generally not be pointed to actual memory. Once the default value is added here we can start removing the various mapping_error methods and just rely on this generic check. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Linus Torvalds <torvalds@linux-foundation.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.