On 06.12.2023 08:10, Juergen Gross wrote:
> Instead of defining get_unaligned() and put_unaligned() in a way that
> is only supporting architectures allowing unaligned accesses, use the
> same approach as the Linux kernel and let the compiler do the
> decision how to generate the code for probably unaligned data accesses.
>
> Update include/xen/unaligned.h from include/asm-generic/unaligned.h of
> the Linux kernel.
>
> The generated code has been checked to be the same on x86.
>
> Modify the Linux variant to not use underscore prefixed identifiers,
> avoid unneeded parentheses and drop the 24-bit accessors.
>
> Signed-off-by: Arnd Bergmann <a...@arndb.de>
> Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> 803f4e1eab7a
> Signed-off-by: Juergen Gross <jgr...@suse.com>
Acked-by: Jan Beulich <jbeul...@suse.com>
Nevertheless ...
> @@ -15,67 +7,82 @@
> #include <asm/byteorder.h>
> #endif
>
> -#define get_unaligned(p) (*(p))
> -#define put_unaligned(val, p) (*(p) = (val))
> +/*
> + * This is the most generic implementation of unaligned accesses
> + * and should work almost anywhere.
> + */
> +
> +#define get_unaligned_t_(type, ptr) ({
> \
..., do we need the trailing underscores here in addition to the already
sufficiently clear _t suffixes? (Leaving aside that ..._t generally is to
denote types, not macros or functions.)
Jan
