Subject: SA and PCI cache coherency ?

From: David Müller (ELSOFT AG) <[email-masked]>
Date: Mon, 26 Jun 2000 11:29:44 +0200

Hi

I have to make a driver for a PCI bus master device (NIC) aware of
the SA PCI cache coherency problem.

Is there a common guideline to do this (I've found nothing on
http://www.arm.linux.org.uk/developer/)?

Is there a "good" example of an already adapted driver
showing me how to do it?

TIA 

Dave

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From: Jamey Hicks <[email-masked]>
Date: Mon, 26 Jun 2000 07:54:20 -0400

David,

There is a new interface in Linux for handling this problem.  It is
documented in Documentation/DMA-mapping.txt.  This documentation does not
mention StrongArm, but use of pci_alloc_consistent() or pci_map_single()
will enable you to solve the data cache coherency problem.

Also, see Documentation/pci for the new PCI driver structure that better
encapsulates probing and supports hot-plug PCI and Cardbus.

We modified the ethernet driver in drivers/net/pcnet32.c to use
pci_alloc_consistent so that it would work on a StrongArm SA110/footbridge.
It's in the mainstream kernel as of 2.4.0-test1.  We also have submitted a
similar patch to drivers/usb/usb-ohci.c.

-Jamey Hicks

> -----Original Message-----
> From: David Müller [mailto:[email-masked]]
> Sent: Monday, June 26, 2000 5:30 AM
> To: [email-masked]
> Subject: SA and PCI cache coherency ?
> 
> 
> Hi
>