440 PCI adapter card DMA question

440 PCI adapter card DMA question

[Khai Trinh]

Matt,

Welcome back to the ppc mailing list. I would like
your answer to my question really bad on the topic of
mapping the PCI bus DMA address to the PLB address
space for setting up the 440GP DMA. I don't have the
email I sent you anymore.

On one of your response email to me, you said the
440GP maps PCI<->PLB 1:1 and I can use the PCI bus
address directly as a PLB address to program the 440GP
DMA controller.

The thing is that the DMA high and low register only
allows 36-bit programming whereas the PCI bus address
given to me by the Host is 64-bit.

Don't I have to manually setup the PCI-PLB mapping
before I can program the DMA controller? OR the 440
kernel has already handle that?

Your comment and response are very important and
appreciated...

Thanks again,
--Khai


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Re: 440 PCI adapter card DMA question

[Matt Porter]

[Please, always start a new mail when starting a new thread.  Don't
 reply to an old one and change the subject, it messes up people
 using mailbox threading.]

On Fri, Aug 16, 2002 at 11:39:15AM -0700, Khai Trinh wrote:
> On one of your response email to me, you said the
> 440GP maps PCI<->PLB 1:1 and I can use the PCI bus
> address directly as a PLB address to program the 440GP
> DMA controller.
>
> The thing is that the DMA high and low register only
> allows 36-bit programming whereas the PCI bus address
> given to me by the Host is 64-bit.

I was answering with respect to the Ebony PCI-X host bridge
configuration.

> Don't I have to manually setup the PCI-PLB mapping
> before I can program the DMA controller? OR the 440
> kernel has already handle that?

The PCI-X host bridge configuration in the Ebony port is
implemented for host operation only (i.e. it has set up
windows and controls BAR assignment within a controlled
PCI address space).  If you need a special translation
for your particular adapter application, you will need
to modify that setup accordingly.

Regards,
--
Matt Porter
porter@cox.net
This is Linux Country. On a quiet night, you can hear Windows reboot.

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