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From: Nicolin Chen <nicoleotsuka@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	krzk@kernel.org, jonathanh@nvidia.com,
	linux-tegra@vger.kernel.org, Dmitry Osipenko <digetx@gmail.com>
Subject: Re: [PATCH v3 2/3] iommu/tegra-smmu: Rework .probe_device and .attach_dev
Date: Thu, 1 Oct 2020 03:33:19 -0700	[thread overview]
Message-ID: <20201001103318.GA1272@Asurada> (raw)
In-Reply-To: <20201001095152.GD3919720@ulmo>

On Thu, Oct 01, 2020 at 11:51:52AM +0200, Thierry Reding wrote:
> > > >> ...
> > > >>>> It looks to me like the only reason why you need this new global API is
> > > >>>> because PCI devices may not have a device tree node with a phandle to
> > > >>>> the IOMMU. However, SMMU support for PCI will only be enabled if the
> > > >>>> root complex has an iommus property, right? In that case, can't we
> > > >>>> simply do something like this:
> > > >>>>
> > > >>>> 	if (dev_is_pci(dev))
> > > >>>> 		np = find_host_bridge(dev)->of_node;
> > > >>>> 	else
> > > >>>> 		np = dev->of_node;
> > > >>>>
> > > >>>> ? I'm not sure exactly what find_host_bridge() is called, but I'm pretty
> > > >>>> sure that exists.

> > @@ -814,12 +815,15 @@ static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
> >  }
> >  
> >  static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
> > -				struct of_phandle_args *args)
> > +				struct of_phandle_args *args, struct fwnode_handle *fwnode)
> >  {
> >  	const struct iommu_ops *ops = smmu->iommu.ops;
> >  	int err;
> >  
> > -	err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
> > +	if (!fwnode)
> > +		return -ENOENT;
> > +
> > +	err = iommu_fwspec_init(dev, fwnode, ops);
> >  	if (err < 0) {
> >  		dev_err(dev, "failed to initialize fwspec: %d\n", err);
> >  		return err;
> > @@ -835,6 +839,19 @@ static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
> >  	return 0;
> >  }
> >  
> > +static struct device_node *tegra_smmu_find_pci_np(struct pci_dev *pci_dev)
> > +{
> > +	struct pci_bus *bus = pci_dev->bus;
> > +	struct device *dev = &bus->dev;
> > +
> > +	while (!of_property_read_bool(dev->of_node, "iommus") && bus->parent) {
> > +		dev = &bus->parent->dev;
> > +		bus = bus->parent;
> > +	}
> > +
> > +	return dev->of_node;
> > +}
> 
> This seems like it's the equivalent of pci_get_host_bridge_device(). Can
> you use that instead? I think you might use the parent of the host
> bridge that's returned from that function, though.

I noticed that one when looking up one of the of_ functions, yet
also found that this pci_get_host_bridge_device() is privated by
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/pci/pci.h?id=975e1ac173058b8710e5979e97fc1397233301f3

Would PCI folks be that willing to (allow to) revert it?
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iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Nicolin Chen <nicoleotsuka@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Dmitry Osipenko <digetx@gmail.com>,
	joro@8bytes.org, krzk@kernel.org, vdumpa@nvidia.com,
	jonathanh@nvidia.com, linux-tegra@vger.kernel.org,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/3] iommu/tegra-smmu: Rework .probe_device and .attach_dev
Date: Thu, 1 Oct 2020 03:33:19 -0700	[thread overview]
Message-ID: <20201001103318.GA1272@Asurada> (raw)
In-Reply-To: <20201001095152.GD3919720@ulmo>

On Thu, Oct 01, 2020 at 11:51:52AM +0200, Thierry Reding wrote:
> > > >> ...
> > > >>>> It looks to me like the only reason why you need this new global API is
> > > >>>> because PCI devices may not have a device tree node with a phandle to
> > > >>>> the IOMMU. However, SMMU support for PCI will only be enabled if the
> > > >>>> root complex has an iommus property, right? In that case, can't we
> > > >>>> simply do something like this:
> > > >>>>
> > > >>>> 	if (dev_is_pci(dev))
> > > >>>> 		np = find_host_bridge(dev)->of_node;
> > > >>>> 	else
> > > >>>> 		np = dev->of_node;
> > > >>>>
> > > >>>> ? I'm not sure exactly what find_host_bridge() is called, but I'm pretty
> > > >>>> sure that exists.

> > @@ -814,12 +815,15 @@ static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
> >  }
> >  
> >  static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
> > -				struct of_phandle_args *args)
> > +				struct of_phandle_args *args, struct fwnode_handle *fwnode)
> >  {
> >  	const struct iommu_ops *ops = smmu->iommu.ops;
> >  	int err;
> >  
> > -	err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
> > +	if (!fwnode)
> > +		return -ENOENT;
> > +
> > +	err = iommu_fwspec_init(dev, fwnode, ops);
> >  	if (err < 0) {
> >  		dev_err(dev, "failed to initialize fwspec: %d\n", err);
> >  		return err;
> > @@ -835,6 +839,19 @@ static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
> >  	return 0;
> >  }
> >  
> > +static struct device_node *tegra_smmu_find_pci_np(struct pci_dev *pci_dev)
> > +{
> > +	struct pci_bus *bus = pci_dev->bus;
> > +	struct device *dev = &bus->dev;
> > +
> > +	while (!of_property_read_bool(dev->of_node, "iommus") && bus->parent) {
> > +		dev = &bus->parent->dev;
> > +		bus = bus->parent;
> > +	}
> > +
> > +	return dev->of_node;
> > +}
> 
> This seems like it's the equivalent of pci_get_host_bridge_device(). Can
> you use that instead? I think you might use the parent of the host
> bridge that's returned from that function, though.

I noticed that one when looking up one of the of_ functions, yet
also found that this pci_get_host_bridge_device() is privated by
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/pci/pci.h?id=975e1ac173058b8710e5979e97fc1397233301f3

Would PCI folks be that willing to (allow to) revert it?

  reply	other threads:[~2020-10-01 10:33 UTC|newest]

Thread overview: 132+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-30  8:42 [PATCH v3 0/3] iommu/tegra-smmu: Add PCI support Nicolin Chen
2020-09-30  8:42 ` Nicolin Chen
2020-09-30  8:42 ` [PATCH v3 1/3] memory: tegra: Add devm_tegra_get_memory_controller() Nicolin Chen
2020-09-30  8:42   ` Nicolin Chen
2020-09-30  9:07   ` Krzysztof Kozlowski
2020-09-30  9:07     ` Krzysztof Kozlowski
2020-09-30  9:41     ` Nicolin Chen
2020-09-30  9:41       ` Nicolin Chen
2020-09-30 10:27       ` Krzysztof Kozlowski
2020-09-30 10:27         ` Krzysztof Kozlowski
2020-09-30 14:41   ` Dmitry Osipenko
2020-09-30 14:41     ` Dmitry Osipenko
2020-09-30 14:45     ` Krzysztof Kozlowski
2020-09-30 14:45       ` Krzysztof Kozlowski
2020-09-30 15:22       ` Dmitry Osipenko
2020-09-30 15:22         ` Dmitry Osipenko
2020-09-30 15:23   ` Thierry Reding
2020-09-30 15:23     ` Thierry Reding
2020-09-30 15:27     ` Dmitry Osipenko
2020-09-30 15:27       ` Dmitry Osipenko
2020-09-30 15:53     ` Dmitry Osipenko
2020-09-30 15:53       ` Dmitry Osipenko
2020-09-30 16:03       ` Thierry Reding
2020-09-30 16:03         ` Thierry Reding
2020-09-30 16:06         ` Dmitry Osipenko
2020-09-30 16:06           ` Dmitry Osipenko
2020-09-30 16:15           ` Thierry Reding
2020-09-30 16:15             ` Thierry Reding
2020-09-30 16:26             ` Dmitry Osipenko
2020-09-30 16:26               ` Dmitry Osipenko
2020-09-30 16:38               ` Thierry Reding
2020-09-30 16:38                 ` Thierry Reding
2020-09-30 17:32                 ` Dmitry Osipenko
2020-09-30 17:32                   ` Dmitry Osipenko
2020-09-30  8:42 ` [PATCH v3 2/3] iommu/tegra-smmu: Rework .probe_device and .attach_dev Nicolin Chen
2020-09-30  8:42   ` Nicolin Chen
2020-09-30  9:21   ` Krzysztof Kozlowski
2020-09-30  9:21     ` Krzysztof Kozlowski
2020-09-30  9:40     ` Nicolin Chen
2020-09-30  9:40       ` Nicolin Chen
2020-09-30 10:19       ` Krzysztof Kozlowski
2020-09-30 10:19         ` Krzysztof Kozlowski
2020-09-30 14:41   ` Dmitry Osipenko
2020-09-30 14:41     ` Dmitry Osipenko
2020-09-30 15:09   ` Dmitry Osipenko
2020-09-30 15:09     ` Dmitry Osipenko
2020-09-30 20:51     ` Nicolin Chen
2020-09-30 20:51       ` Nicolin Chen
2020-09-30 15:31   ` Thierry Reding
2020-09-30 15:31     ` Thierry Reding
2020-09-30 15:36     ` Dmitry Osipenko
2020-09-30 15:36       ` Dmitry Osipenko
2020-09-30 16:06       ` Thierry Reding
2020-09-30 16:06         ` Thierry Reding
2020-09-30 16:25         ` Dmitry Osipenko
2020-09-30 16:25           ` Dmitry Osipenko
2020-09-30 16:47           ` Thierry Reding
2020-09-30 16:47             ` Thierry Reding
2020-10-01  2:11             ` Dmitry Osipenko
2020-10-01  2:11               ` Dmitry Osipenko
2020-10-01  7:58               ` Thierry Reding
2020-10-01  7:58                 ` Thierry Reding
2020-10-01 19:04                 ` Dmitry Osipenko
2020-10-01 19:04                   ` Dmitry Osipenko
2020-10-05  9:16                   ` Thierry Reding
2020-10-05  9:16                     ` Thierry Reding
2020-10-05  9:38                     ` Dmitry Osipenko
2020-10-05  9:38                       ` Dmitry Osipenko
2020-10-05 10:27                       ` Thierry Reding
2020-10-05 10:27                         ` Thierry Reding
2020-09-30 16:10       ` Thierry Reding
2020-09-30 16:10         ` Thierry Reding
2020-09-30 16:29         ` Dmitry Osipenko
2020-09-30 16:29           ` Dmitry Osipenko
2020-10-01  7:59           ` Thierry Reding
2020-10-01  7:59             ` Thierry Reding
2020-09-30 20:36     ` Nicolin Chen
2020-09-30 20:36       ` Nicolin Chen
2020-09-30 21:24       ` Dmitry Osipenko
2020-09-30 21:24         ` Dmitry Osipenko
2020-09-30 21:32         ` Nicolin Chen
2020-09-30 21:32           ` Nicolin Chen
2020-09-30 21:56           ` Dmitry Osipenko
2020-09-30 21:56             ` Dmitry Osipenko
2020-10-01  1:26             ` Nicolin Chen
2020-10-01  1:26               ` Nicolin Chen
2020-10-01  2:06               ` Dmitry Osipenko
2020-10-01  2:06                 ` Dmitry Osipenko
2020-10-01  2:48                 ` Nicolin Chen
2020-10-01  2:48                   ` Nicolin Chen
2020-10-01  4:04                   ` Dmitry Osipenko
2020-10-01  4:04                     ` Dmitry Osipenko
2020-10-01 10:23                   ` Thierry Reding
2020-10-01 10:23                     ` Thierry Reding
2020-10-01 11:04                     ` Nicolin Chen
2020-10-01 11:04                       ` Nicolin Chen
2020-10-01 20:33                       ` Dmitry Osipenko
2020-10-01 20:33                         ` Dmitry Osipenko
2020-10-02  1:07                         ` Nicolin Chen
2020-10-02  1:07                           ` Nicolin Chen
2020-10-02  1:55                           ` Dmitry Osipenko
2020-10-02  1:55                             ` Dmitry Osipenko
2020-10-02  2:54                             ` Nicolin Chen
2020-10-02  2:54                               ` Nicolin Chen
2020-10-05  7:24                             ` Thierry Reding
2020-10-05  7:24                               ` Thierry Reding
2020-10-05  7:13                         ` Thierry Reding
2020-10-05  7:13                           ` Thierry Reding
2020-10-05  8:14                           ` Dmitry Osipenko
2020-10-05  8:14                             ` Dmitry Osipenko
2020-10-05  9:31                             ` Thierry Reding
2020-10-05  9:31                               ` Thierry Reding
2020-10-01  9:54                 ` Thierry Reding
2020-10-01  9:54                   ` Thierry Reding
2020-10-01  9:51               ` Thierry Reding
2020-10-01  9:51                 ` Thierry Reding
2020-10-01 10:33                 ` Nicolin Chen [this message]
2020-10-01 10:33                   ` Nicolin Chen
2020-10-01 10:42                   ` Thierry Reding
2020-10-01 10:42                     ` Thierry Reding
2020-10-01  9:47       ` Thierry Reding
2020-10-01  9:47         ` Thierry Reding
2020-10-01 10:46       ` Thierry Reding
2020-10-01 10:46         ` Thierry Reding
2020-10-02  1:29         ` Nicolin Chen
2020-10-02  1:29           ` Nicolin Chen
2020-09-30  8:42 ` [PATCH v3 3/3] iommu/tegra-smmu: Add PCI support Nicolin Chen
2020-09-30  8:42   ` Nicolin Chen
2020-09-30 14:53   ` Dmitry Osipenko
2020-09-30 14:53     ` Dmitry Osipenko
2020-09-30 20:03     ` Nicolin Chen
2020-09-30 20:03       ` Nicolin Chen

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