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From: "Cédric Cano" <ccano@interfaceconcept.com>
To: linux-pci@vger.kernel.org
Subject: Question: how can I get the real PCI address of a BAR?
Date: Fri, 28 Dec 2012 10:36:17 +0100	[thread overview]
Message-ID: <50DD6811.7020301@ic.fr> (raw)

Hi,

I'm writing a driver for a DMA engine on the PCI bus. My architecture is 
a 36-bit PowerPC (MPC85xx).

In my DMA driver, I want to configure the DMA to transfer data to/from a 
PCI device.
I get the PCI address of the device BAR with the command pci_resource_start.
This address is 36-bit but the PCI BAR of the device is 32-bit: I can't 
use the 36-bit address to run the DMA.

In kernel documentations, it's advised not to directly read the BAR.

Is there a function which provides the real PCI address i.e. the one 
stored in the BAR?

Thanks.

C. Cano




             reply	other threads:[~2012-12-28 14:25 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-28  9:36 Cédric Cano [this message]
2012-12-30 19:46 ` Question: how can I get the real PCI address of a BAR? Bjorn Helgaas
2013-01-03  8:58   ` Cédric Cano

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