From: gregkh@linuxfoundation•org (gregkh at linuxfoundation.org)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/2] arm/xen: Don't use xen DMA ops when the device is protected by an IOMMU
Date: Fri, 14 Mar 2014 23:56:37 +0000 [thread overview]
Message-ID: <20140314235637.GA5687@kroah.com> (raw)
In-Reply-To: <5323334F.90700@linaro.org>
On Fri, Mar 14, 2014 at 04:50:23PM +0000, Julien Grall wrote:
> On 02/24/2014 08:49 PM, Stefano Stabellini wrote:
> > On Mon, 24 Feb 2014, gregkh at linuxfoundation.org wrote:
> > Julien is proposing to store the list of "safe" devices on an hash table
> > in the Xen specific code (in arch/arm/xen/enlighten.c, see
> > http://marc.info/?l=linux-kernel&m=139291370526082&w=2).
> > Whenever Linux is about to do DMA, we would check in the hashtable to
> > figure out whether we need to go through the swiotlb or we can simply
> > use the native dma_ops.
> >
> > Ian and I were thinking that it would be much easier and faster to have
> > a "xen_safe_device" parameter in struct device and just check for that.
> > It doesn't actually need to be in struct device, it could simply be a
> > flag in struct device_dma_parameters as Ian was suggesting.
> >
> > Julien, could you please come up with a simple patch to demonstrate the
> > concept?
>
> Hello Stefano and Greg,
>
> Sorry for the late answer. I wrote a simple patch which depend on patch #1.
> Let me know if it's the right direction.
I have no context here, care to start the patch series over?
thanks,
greg k-h
next prev parent reply other threads:[~2014-03-14 23:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-20 16:21 [PATCH 2/2] arm/xen: Don't use xen DMA ops when the device is protected by an IOMMU Julien Grall
2014-02-20 16:35 ` Ian Campbell
2014-02-24 12:19 ` Stefano Stabellini
2014-02-24 15:16 ` gregkh at linuxfoundation.org
2014-02-24 20:49 ` Stefano Stabellini
2014-03-01 15:33 ` Julien Grall
2014-03-14 16:50 ` Julien Grall
2014-03-14 23:56 ` gregkh at linuxfoundation.org [this message]
2014-02-20 17:13 ` Ian Campbell
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