Re: [PATCH v2 04/20] unify generic instances of csum_partial_copy_nocheck()

[Christoph Hellwig]

On Fri, Jul 24, 2020 at 02:25:30AM +0100, Al Viro wrote:
> From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> 
> quite a few architectures have the same csum_partial_copy_nocheck() -
> simply memcpy() the data and then return the csum of the copy.
> 
> hexagon, parisc, ia64, s390, um: explicitly spelled out that way.
> 
> arc, arm64, csky, h8300, m68k/nommu, microblaze, mips/GENERIC_CSUM, nds32,
> nios2, openrisc, riscv, unicore32: end up picking the same thing spelled
> out in lib/checksum.h (with varying amounts of perversions along the way).
> 
> everybody else (alpha, arm, c6x, m68k/mmu, mips/!GENERIC_CSUM, powerpc,
> sh, sparc, x86, xtensa) have non-generic variants.  For all except c6x
> the declaration is in their asm/checksum.h.  c6x uses the wrapper
> from asm-generic/checksum.h that would normally lead to the lib/checksum.h
> instance, but in case of c6x we end up using an asm function from arch/c6x
> instead.
> 
> Screw that mess - have architectures with private instances define
> _HAVE_ARCH_CSUM_AND_COPY in their asm/checksum.h and have the default
> one right in net/checksum.h conditional on _HAVE_ARCH_CSUM_AND_COPY
> *not* defined.

net-next has a patch from me killing off csum_and_copy_from_user
already:

https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=f1bfd71c8662f20d53e71ef4e18bfb0e5677c27f