From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCHv7 04/12] driver/core: populate devices in order for IOMMUs Date: Thu, 12 Dec 2013 18:14:02 -0800 Message-ID: <20131213021402.GB14192@kroah.com> References: <1386835033-4701-1-git-send-email-hdoyu@nvidia.com> <1386835033-4701-5-git-send-email-hdoyu@nvidia.com> <20131212113920.70E8BC40637@trevor.secretlab.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20131212113920.70E8BC40637-WNowdnHR2B42iJbIjFUEsiwD8/FfD2ys@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Grant Likely Cc: mark.rutland-5wv7dgnIgG8@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org, swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, Stephen Warren , will.deacon-5wv7dgnIgG8@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-tegra@vger.kernel.org On Thu, Dec 12, 2013 at 11:39:20AM +0000, Grant Likely wrote: > On Thu, 12 Dec 2013 09:57:05 +0200, Hiroshi Doyu wrote: > > IOMMU devices on the bus need to be poplulated first, then iommu > > master devices are done later. > > > > With CONFIG_OF_IOMMU, "iommus=" DT binding would be used to identify > > whether a device can be an iommu msater or not. If a device can, we'll > > defer to populate that device till an iommu device is populated. Then, > > those deferred iommu master devices are populated and configured with > > help of the already populated iommu device. > > > > Signed-off-by: Hiroshi Doyu > > Cc: Greg Kroah-Hartman > > --- > > This is related to the following discussion: > > [RFC PATCH] Documentation: devicetree: add description for generic bus properties > > http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/215042.html > > > > v6: > > Spinned off only driver core part from: > > [PATCHv5 2/9] driver/core: populate devices in order for IOMMUs > > > > v5: > > Use "iommus=" binding instread of arm,smmu's "#stream-id-cells". > > > > v4: > > This is newly added, and the successor of the following RFC: > > [RFC][PATCHv3+ 1/2] driver/core: Add of_iommu_attach() > > http://lists.linuxfoundation.org/pipermail/iommu/2013-November/006914.html > > > > Signed-off-by: Hiroshi Doyu > > --- > > drivers/base/dd.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > > index 0605176..0605f52 100644 > > --- a/drivers/base/dd.c > > +++ b/drivers/base/dd.c > > @@ -25,6 +25,7 @@ > > #include > > #include > > #include > > +#include > > > > #include "base.h" > > #include "power/power.h" > > @@ -273,6 +274,10 @@ static int really_probe(struct device *dev, struct device_driver *drv) > > > > dev->driver = drv; > > > > + ret = of_iommu_attach(dev); > > + if (ret) > > + goto probe_failed; > > + > > As discussed before, I really don't think hooking in to dd.c is the > right thing to do here, and certainly not as a device tree specific > function. ACPI or PCI described devices may have the same constraints > and those won't have DT descriptions. I agree, this shouldn't be in the driver core. greg k-h