Added NT BAR Setup Extension Registers for large MWs

[PaulSelles]

For direct memory windows greater than (4G-4K), the BAR Setup Extension Registers need to be used.

This pull request was created to resolve the 4G issue in Issue 8: MW 2M limitation

[lsgunth]

Looks good to me. Thanks!

[glimchb]

Please merge

[glimchb]

@wesleywesley - please review and merge

[glimchb]

@wesleywesley - please review and merge

[wesleywesley]

Actually, we have review the code internally.
But before the code merge, we will verify on EVB.

[glimchb]

@wesleywesley ok, thanks. good to know.
I already verified it on my machine... you can also go ahead and verify it on EVB as well

[wesleywesley]

@glimchb would you pls tell me the FW version and configure file you used for verification. I will setup the test environment and verified in my place.

[glimchb]

@wesleywesley this is the FW version:

$ switchtec fw-info 0

Currently Running:
  IMG Version: 1.08 BD58
Active Partition:
  BOOT 	Version: 1.08 BD58	CRC: 725a8d2e   (RO)
  IMG  	Version: 1.08 BD58	CRC: 3b0e90b2	(Running)
  CFG  	Version: 1.08 B3F08	CRC: 9efdc91b	(Running)
Inactive Partition:
  IMG  	Version: 1.08 BD58	CRC: 3b0e90b2
  CFG  	Version: 1.08 B3F08	CRC: 60c359aa

For the configuration: I just enlarged the BAR2/4 to 16G to test...
See it attached here: 16g.zip

[glimchb]

@lsgunth will this work be also take upstream?

[lsgunth]

I hope so. I don't know who's responsible for that anymore.

[glimchb]

@lsgunth Isn't it a straight forward approach just to send a patch to linux-ntb@googlegroups.com ?
@PaulSelles could you please send it ?

[PaulSelles]

@glimchb I'll look into this.

@lsgunth FYI you are still listed as one of the maintainers https://www.kernel.org/doc/linux/MAINTAINERS

[lsgunth]

Yes, I'm still maintainer and have been acting as such: reviewing patches that hit the lists concerning the switchtec code. Anyone is free to send the patch upstream and I'll review it there (you'll definitely want to expand the commit message significantly, though, and it must have a sign-off from the author).

At an appropriate time someone should be collecting all the changes on github and sending patches upstream. The best time would be next week when the merge window ends. If Microsemi is interested in contracting me for this type of maintenance I'd be happy to do it, otherwise I'll stick to a reviewing role.

Logan