[PATCH v19 03/10] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check

[Manivannan Sadhasivam]

On Mon, Jun 09, 2025 at 12:34:15PM GMT, Frank Li wrote:
> Some MSI controller change address/data pair when irq_set_affinity().
> Current PCI endpoint can't support this type MSI controller. Call
> irq_domain_is_msi_immutable() check if address/data pair immutable.
> 
> Signed-off-by: Frank Li <Frank.Li at nxp.com>
> ---
> change in v18
> - update commit message. remove 'include/linux/msi.h' part.
> 
> change from v14 to v17
> - none
> 
> change from  v13 to v14
> - bring v10 back
> 
> Change from v9 to v10
> - new patch
> ---
>  drivers/pci/endpoint/pci-ep-msi.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c
> index 549b55b864d0e..c0e2d806ee658 100644
> --- a/drivers/pci/endpoint/pci-ep-msi.c
> +++ b/drivers/pci/endpoint/pci-ep-msi.c
> @@ -44,6 +44,14 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
>  
>  	dev_set_msi_domain(dev, dom);
>  
> +	if (!irq_domain_is_msi_parent(dom))
> +		return -EINVAL;

This check is not justified in commit message.

> +
> +	if (!irq_domain_is_msi_immutable(dom)) {
> +		dev_err(dev, "Can't support mutable address/data pair MSI controller\n");
> +		return -EINVAL;

GICv3 ITS is an immutable MSI controller. From the earlier patches, I could see
that you have tested this series with ITS. How did that happen if it errors out
here?

- Mani

-- 
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