[PATCH v12 5/9] PCI: endpoint: pci-ep-msi: Add check for MSI address/data pair immutability

[Frank Li]

Check the immutability of the MSI address/data pair by calling
irq_domain_is_msi_immutable() when allocating a doorbell.

Prevent the use of MSI controllers that change the address/data pair during
irq_set_affinity(), as the current PCI endpoint implementation does not
support such behavior.

Signed-off-by: Frank Li <Frank.Li at nxp.com>
---
Change from v11 to v12
- use helper function irq_domain_is_msi_immutable().
- remove msi parent check.
- split msi header, its and endpoint to 3 patches.
- rework commit message.

Change from v9 to v11
- new patch
---
 drivers/pci/endpoint/pci-ep-msi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c
index b0a91fde202f3..eda027b734b73 100644
--- a/drivers/pci/endpoint/pci-ep-msi.c
+++ b/drivers/pci/endpoint/pci-ep-msi.c
@@ -107,6 +107,11 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
 		return -EINVAL;
 	}
 
+	if (!irq_domain_is_msi_immutable(dom)) {
+		dev_err(dev, "Can't support mutable address/data pair MSI controller\n");
+		return -EINVAL;
+	}
+
 	dev_set_msi_domain(dev, dom);
 
 	msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);

-- 
2.34.1