Re: [PATCH v3 03/11] iommu: Compute iommu_groups properly for PCIe switches

[Jason Gunthorpe <jgg@nvidia.com>]

On Tue, Sep 09, 2025 at 12:14:00AM -0400, Donald Dutile wrote:

> > -/*
> > - * Use standard PCI bus topology, isolation features, and DMA alias quirks
> > - * to find or create an IOMMU group for a device.
> > - */
> > -struct iommu_group *pci_device_group(struct device *dev)
> > +static struct iommu_group *pci_group_alloc_non_isolated(void)

> Maybe iommu_group_alloc_non_isolated() would be a better name, since that's all it does.

The way I've organized it makes the bus data a per-bus thing, so
having pci in the name when setting BUS_DATA_PCI_NON_ISOLATED is
correct.

What I did was turn iommu_group_alloc() into 

static struct iommu_group *iommu_group_alloc_data(u32 bus_data)

Then

struct iommu_group *iommu_group_alloc(void)
{
	return iommu_group_alloc_data(0);
}

And instead of pci_group_alloc_non_isolated() it is just:

	return iommu_group_alloc_data(BUS_DATA_PCI_NON_ISOLATED);

So everything is setup generically if someday another bus would like
to have its own data.

Jason