option NEW_PCIB

[John Baldwin]

On Friday, March 07, 2014 9:38:33 am Warner Losh wrote:
> 
> On Mar 7, 2014, at 6:52 AM, Ian Lepore <ian at FreeBSD.org> wrote:
> 
> > Every architecture has "option NEW_PCIB" in its conf/DEFAULTS except arm
> > and mips.  Is that on purpose?  What are the implications of adding it?
> > Or maybe more importantly, what are the implications of it not being
> > there?
> 
> This is John Baldwin’s option for his reworked PCI bridge code. He did that as
> a fallback in case he really messed up something. It introduces renumbering
> of busses that don’t already have numbers assigned. It should be enabled on
> ARM, but the required resource isn’t defined on arm, and some of the other
> required glue doesn’t seem to be implemented for arm yet, which is why things
> are the way they are at the moment. I think John intends for the option to go
> away, and everything it covers will be ‘standard’.

Yes.  I just added a page on the wiki about NEW_PCIB explaining the changes
each platform needs for it in a bit more detail on Friday:

   https://wiki.freebsd.org/NEW_PCIB

I have posted patches in the past to arm@ to handle step 2 in the NEW_PCIB
base requirements for arm@ but haven't been able to get folks to test them.
I just recently made a new pass through sys/arm in a p4 tree to refresh this.
I haven't even compiled these yet, but you can find the patch here:

   http://people.freebsd.org/~jhb/patches/arm_activate2.patch

I don't know how best to think about fixing i80321_pci to work with NEW_PCIB.
It has some hack that I don't fully understand.  I think it uses an
alternate mapping of the same resource range to use a different base address
for the mapping.  Longer term I think the bus_map_resource() think I suggest
at the bottom is how to handle that, but even then there would still need to
be a way to know which base address a given resource wanted to use.  It may
be that we need to implement that differently (bus-specific rman flag?)

-- 
John Baldwin