Re: MI overrides of bus_dma(9), bus_space(9), pci(9)

[Matt Thomas <matt%3am-software.com@localhost>]

On Mar 11, 2010, at 12:31 PM, David Young wrote:

> On Thu, Mar 11, 2010 at 12:20:41PM -0800, Matt Thomas wrote:
>> On Mar 11, 2010, at 11:40 AM, David Young wrote:
>>> Resource management:
>>> 
>>>   PCI-* bridges can override bus_space_alloc(9)/bus_space_free(9)
>>>       in order to (1) allocate space from the upstream bus, (2)
>>>       widen/narrow its I/O- or memory-space window.  Then we can
>>>       provide a reliable rbus-like facility to detachable buses
>>>       through bus_space(9).
>> 
>> bus_dma_subregion can be used for that.  So bus_space_subregion.
> 
> Matt,
> 
> How do we open the windows?

I don't see a reason to do that but you could allocate new larger 
subregions from the parent.