restoring PCI config space

[Scott Long]

Andrew Gallatin wrote:
> I need to write a watchdog handler for mxge(4).  The catch is that if
> the NIC resets due to a hardware error, it will reset its config space
> (setting BAR to 0, disabling DMA, forgetting MSI addr/data, etc), so
> the driver's watchdog handler needs to be able to restore it.  How do
> I do this properly on FreeBSD?
> 
> Browsing around the source tree, I see that the pci function
> pci_cfg_restore() seems to do exactly what I want, but it is private
> to the pci code, and seems to be called from the bowels of the resume
> path.  Is there a clean way I can leverage pci_cfg_restore(), or
> should I just save an extra copy of the device's PCI config space
> myself?
> 
> Thanks,
> 
> Drew
> 

I need to do the same thing, and I concluded that pci_cfg_restore needs
to be exported out via a DEVMETHOD.  It might also be useful to export
a pci_cfg_save function.

Scott