From: gerlando.falauto@keymile•com (Gerlando Falauto)
To: linux-arm-kernel@lists•infradead.org
Subject: address translation for PCIe-to-localbus bridge
Date: Tue, 12 Nov 2013 09:11:33 +0100 [thread overview]
Message-ID: <5281E2B5.3080701@keymile.com> (raw)
In-Reply-To: <20131112080512.3992b2e4@skate>
On 11/12/2013 08:05 AM, Thomas Petazzoni wrote:
> Dear Grant Likely,
>
> On Mon, 11 Nov 2013 15:50:50 +0000, Grant Likely wrote:
>
>>> So the mbus would register an address xlate for its node that is
>>> called instead of ranges parsing. For the example in my last message
>>> the FPGA driver would register an xlate that made addresses relative
>>> to its own BAR0 address.
>>
>> There are already bus-specific transations available. Take a look at
>> struct of_bus in drivers/of/address.c
>
> Hum, right, but unless I'm wrong the of_busses[] array of struct of_bus
> is fixed in drivers/of/address.c, and as it is, there is no way for a
> specific bus driver to provide its own struct of_bus.
That was exactly my understanding as well, and that's where I was
expecting some trickery to happen.
> So that would need to be extended, right?
The other approach I was foreseeing was to implement a way of
dynamically updating the DT when the PCI subsystem enumerates the
devices and assigns memory areas (namely, I would expect the ranges
property to reflect that). But this would imply a standard way of
defining the ranges property (I would expect something like <bar#
start_addr length>, with an arguable number of cells). And I could
not find any such definition in the PCI bus binding document, so I'm
probably completely off-track here. Aren't I?
After all, we should expect a driver to behave (and expect) the same of
the DT, regardless of whether enumeration was performed by firmware or
by the OS itself. Or am I wrong on this too?
Thanks guys!
Gerlando
next prev parent reply other threads:[~2013-11-12 8:11 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-06 10:27 address translation for PCIe-to-localbus bridge Gerlando Falauto
2013-11-06 12:23 ` Thierry Reding
2013-11-06 12:50 ` Gerlando Falauto
2013-11-06 17:36 ` Jason Gunthorpe
2013-11-06 18:03 ` Thomas Petazzoni
2013-11-06 18:24 ` Jason Gunthorpe
2013-11-06 19:00 ` Thomas Petazzoni
2013-11-11 15:50 ` Grant Likely
2013-11-12 7:05 ` Thomas Petazzoni
2013-11-12 8:11 ` Gerlando Falauto [this message]
2013-11-12 8:16 ` Thomas Petazzoni
2013-11-12 8:26 ` Gerlando Falauto
2013-11-13 6:26 ` Grant Likely
2013-11-12 8:51 ` Grant Likely
2013-11-06 18:33 ` Pantelis Antoniou
2013-11-06 18:56 ` Jason Gunthorpe
2013-11-06 19:16 ` Pantelis Antoniou
2013-11-06 19:50 ` Jason Gunthorpe
2013-11-06 19:38 ` Gerlando Falauto
2013-11-06 20:07 ` Jason Gunthorpe
2013-11-07 9:07 ` Gerlando Falauto
2013-11-07 17:01 ` Jason Gunthorpe
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