Need to arbitrarily set PCI-PCI bridge memory window size.

[jfaslist]

Problem: Need to arbitrarily set PCI-PCI bridge memory window size.

We have designed a VME board based on the IBM 970 Maple design.
For accessing VME, we use the PCI-VME Tundra Universe2 bridge.
(http://www.tundra.com/Products/Bridges/UniverseII/index.cfm)
It's located on the PCI bus hanging from the AMD8111.
The PCI-VME  bridge works by translating a range of PCI addresses 
(1Gbytes in my case) to VME. 
So I need the AMD8111 memory window  (PCI CFG off 0x20) to be wide 
enough to let that range
of PCI addresses reach the subordinate PCI bus that holds the PCI-VME 
bridge.
The problem is that the PCI_VME controller BARs only defines and map the 
chip  register sets (4KB). And it looks
like  the ppc64  linux kernel will  set a memory window in the AMD8111 
just large enough to meet requirements of
BARs from devices on the subordinate bus.

Is there a way I can tell linux to program a wider window to let through 
the PCI to VME range of addresses?
Currently I manually program the AMD8111 from my VME driver, but it is 
just a hack. I have also tried to set
the window from the firmware but linux doesn't care.

Thanks a lot!

-- 

Best regards,
_______________________________________
jean-francois simon - themis computer
5, rue irene joliot curie
38330 eybens - france
+33 (0)4 76 14 77 85


 

	

	
		
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