From: David Gibson <david@gibson.dropbear.id.au>
To: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
Avi Kivity <avi@redhat.com>,
patches@linaro.org, Gerd Hoffmann <kraxel@redhat.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] dma: Define dma_context_memory and use in sysbus-ohci
Date: Fri, 26 Oct 2012 11:48:32 +1100 [thread overview]
Message-ID: <20121026004832.GG7222@truffula.fritz.box> (raw)
In-Reply-To: <CAEgOgz7xTwcdP_MAGaU6jpqs0ms9E6MyF_e4P4ivNdV_QPJGrA@mail.gmail.com>
On Thu, Oct 25, 2012 at 08:33:13PM +1000, Peter Crosthwaite wrote:
> On Oct 24, 2012 3:27 AM, "Peter Maydell" <peter.maydell@linaro.org> wrote:
> >
> > Define a new global dma_context_memory which is a DMAContext corresponding
> > to the global address_space_memory AddressSpace. This can be used by
> > sysbus peripherals like sysbus-ohci which need to do DMA.
> >
> > In particular, use it in the sysbus-ohci device, which fixes a
> > segfault when attempting to use that device.
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Hrm. So, as I originally conceived DMAContext, a NULL context pointer
means "no translation" which is to say that DMA addresses are the same
as memory space addresses. Which would mean a context explicitly for
this purpose should not be necessary.
Has this assumption changed with the newer memory region integrated
dma context stuff?
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
next prev parent reply other threads:[~2012-10-26 0:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-23 17:26 [Qemu-devel] [PATCH] dma: Define dma_context_memory and use in sysbus-ohci Peter Maydell
2012-10-25 10:33 ` Peter Crosthwaite
2012-10-26 0:48 ` David Gibson [this message]
2012-10-26 2:53 ` Peter Crosthwaite
2012-10-26 3:58 ` David Gibson
2012-10-26 13:09 ` Paolo Bonzini
2012-10-26 16:00 ` Peter Maydell
2012-11-13 11:44 ` Peter Maydell
2012-11-13 15:04 ` Paolo Bonzini
2012-11-13 15:21 ` Gerd Hoffmann
2012-11-13 15:26 ` Paolo Bonzini
2012-11-18 16:53 ` Avi Kivity
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