[PATCH v7 1/5] lib/bitmap: add bitmap_{read,write}()

[Alexander Potapenko]

>
> I realized that the corner case with these functions is when agnostic user
> wants to read / write > 32 bits at a time without ifdeffery applied.

Shall we change

        if (unlikely(!nbits))
                return;

to

        if (unlikely(!nbits || nbits > BITS_PER_LONG))
                return;

?

> At bare minimum this has to be documented explicitly, that callers
> may have an issue of the above calls on 32-bit platforms.

Given that bitmap_read() returns an unsigned long, and bitmap_write()
writes an unsigned long, passing a 64-bit value would be a bug.
But you are right, documenting this won't hurt.