PCI BAR mmap

John Baldwin jhb at freebsd.org
Tue Jul 31 16:13:57 UTC 2012


On Tuesday, July 31, 2012 11:22:25 am Venkat Duvvuru wrote:
> Hi John,
> Thanks for your response.
> Is there an alternative to mmap the PCI BARs, I mean without implementing
> an mmap method in the driver, something like a pci subsystem mmap in Linux.
> Linux allows to mmap PCI BARs without any change in the device driver.

No, we do not currently have a generic way to mmap PCI BARs.

> /Venkat
> 
> On Tue, Jul 31, 2012 at 7:21 PM, John Baldwin <jhb at freebsd.org> wrote:
> 
> >  On Tuesday, July 31, 2012 8:48:00 am Venkat Duvvuru wrote:
> > > Hi,
> > > How to mmap PCI  BARs from userland in freebsd?
> > > In Linux the PCI BAR appears as a file in the sysfs file system. How can
> > I
> > > access PCI BAR as a file in freebsd to mmap it?
> >
> > You can export a BAR via a d_mmap() method from a cdevsw device you create
> > in
> > your driver.
> >
> > --
> > John Baldwin
> >
> 

-- 
John Baldwin


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