mirror of https://gitee.com/openkylin/linux.git
803f4e1eab
The get_unaligned()/put_unaligned() implementations are much more complex than necessary, now that all architectures use the same code. Move everything into one file and use a much more compact way to express the same logic. I've compared the binary output using gcc-11 across defconfig builds for all architectures and found this patch to make no difference, except for a single function on powerpc that needs two additional register moves because of random differences in register allocation. There are a handful of callers of the low-level __get_unaligned_cpu32, so leave that in place for the time being even though the common code no longer uses it. This adds a warning for any caller of get_unaligned()/put_unaligned() that passes in a single-byte pointer, but I've sent patches for all instances that show up in x86 and randconfig builds. It would be nice to change the arguments of the endian-specific accessors to take the matching __be16/__be32/__be64/__le16/__le32/__le64 arguments instead of a void pointer, but that requires more changes to the rest of the kernel. This new version does allow aggregate types into get_unaligned(), which was not the original goal but might come in handy. Signed-off-by: Arnd Bergmann <arnd@arndb.de> |
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| fs | ||
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| kernel | ||
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| README | ||
README
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.