Re: [PATCH v6 02/12] iommu: Add pasid_bits field in struct dev_iommu

From: Jason Gunthorpe via iommu <iommu@lists.linux-foundation.org>
To: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Kevin Tian <kevin.tian@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Ashok Raj <ashok.raj@intel.com>,
	Robin Murphy <robin.murphy@arm.com>,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	Christoph Hellwig <hch@infradead.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>,
	Vinod Koul <vkoul@kernel.org>,
	Jacob jun Pan <jacob.jun.pan@intel.com>,
	Will Deacon <will@kernel.org>
Subject: Re: [PATCH v6 02/12] iommu: Add pasid_bits field in struct dev_iommu
Date: Wed, 11 May 2022 08:59:52 -0300	[thread overview]
Message-ID: <20220511115952.GX49344@nvidia.com> (raw)
In-Reply-To: <YnttMpX2geTKRzVV@myrica>

On Wed, May 11, 2022 at 09:00:50AM +0100, Jean-Philippe Brucker wrote:

> > /**
> >  * struct iommu_device - IOMMU core representation of one IOMMU hardware
> >  *                       instance
> >  * @list: Used by the iommu-core to keep a list of registered iommus
> >  * @ops: iommu-ops for talking to this iommu
> >  * @dev: struct device for sysfs handling
> >  */
> > struct iommu_device {
> >         struct list_head list;
> >         const struct iommu_ops *ops;
> >         struct fwnode_handle *fwnode;
> >         struct device *dev;
> > };
> > 
> > I haven't checked ARM code yet, but it works for x86 as far as I can
> > see.
> 
> Arm also supports non-PCI PASID by reading a firmware property:
> 
>         device_property_read_u32(dev, "pasid-num-bits", &master->ssid_bits);
> 
> should be the only difference

That is not "ARM" that is generic DT/ACPI for platform devices and
should be handled by the core code in the same place it does PCI
discovery.

Jason
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu