On Thu, Jan 31, 2019 at 10:51 AM Linus Torvalds
[off-list ref] wrote:

In fact, we have another patch (that isn't applied) that makes even
the memcpy_erms() just call the sw version of memcpy() for short
copies (because "rep movsb" is slow for those cases). That would also
have broken your driver.

I think what I should do is to just make "memcpy_*io()" do the "align
naturally" thing.

Let me cook up a patch for you to test.

              Linus