Re: [patch][rfa]: SID mapper component - wordsize

[fche at redhat dot com (Frank Ch. Eigler)]

brolley wrote:

> [...] The specification
> [4*1000-1010]
> should allow access to the range 4000-4043, however, the upper bound
> is simply being multiplied by the wordsize, resulting in an upper
> bound of 4040.

Actually, addresses in the mapper specs are inclusive, not exclusive.
That's why one often sees ranges ending with ...ffff.  Plain raw
scaling such inclusive limits doesn't make sense though, so a special
case calculation like yours would make sense.  However, care should be
taken not to confuse exclusive vs inclusive bounds.

> If the mapper is accessed using wordsized elements, the problem goes
> unnoticed, since the mapper does not check the ending address of the
> range being accessed.

That's a peculiar other bug.  To be consistent with the byte-oriented
addressing across sid::bus, the size of the access would need to be
included in the checks.


- FChE