Successful master window access

[Oliver Korpilla <okorpil@fh-landshut.de>]

Hello!

While vme_dma_read() and vme_dma_write() worked already, even on the PowerPC,
vme_peek() and vme_poke() (both based on PCI master windows) did not work.

Today I successfully made accesses using that functions with my modified module,
giving me the desired results:

1st test: MVME2100 (PPC) master - MVME162 (68k) slave
vme_dma_read -A <VME address @ slave board> -d VME_D32
vme_peek -A <VME address @ slave board> -d VME_D32
Produced the same result for both accesses.

2nd test: MVME2100 (PPC) master - MVME162 (68k) slave
vme_dma_write -A <VME address @ slave board> -d VME_D32 0xDEADFACE
vme_peek -A <VME address @ slave board> -d VME_D32
Produced the written value on reading.

It seems, though I have to verify 1st, doing two things did the trick:

1.) Acquiring the PCI Window address range from the PCI bus address range of the
bridge's PCI bus.
2.) Writing a help function that converts the physical address to a PCI bus
address (doing nothing for x86, and on PPC doing a conversion). Only this
address may be used when writing to the Universe window registers.

It seems this may be a solution that should work for both platforms.

Somehow I'm very excited and happy! :)

I will go clean up that code, test it more thoroughly (with tracers enabled),
focus on slave windows afterwards, and maybe even get to test it on a VMIVME7698
- to verify it is still correct on Intel.

When I got something more substantial than the current hack, I'll submit it to
you, of course.

With kind regards,
Oliver Korpilla

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