[PATCH v21 4/9] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check

[Frank Li via B4 Relay <devnull+Frank.Li.nxp.com@kernel.org>]

From: Frank Li <Frank.Li@nxp.com>

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.

Also ensure it is parent MSI domains, not device-specific MSI domains,
since device MSI domains do not allocate address/data pairs.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v20
- update commit message
- change return error code to ENODEV

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 de610c16f68986eb0a5f4a0f23bd0136aa169f97..2b4405cfeb6f8f3cbe9782c793604a10dcaa4eb7 100644
--- a/drivers/pci/endpoint/pci-ep-msi.c
+++ b/drivers/pci/endpoint/pci-ep-msi.c
@@ -55,6 +55,14 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
 		return -ENODEV;
 	}
 
+	if (!irq_domain_is_msi_parent(dom))
+		return -ENODEV;
+
+	if (!irq_domain_is_msi_immutable(dom)) {
+		dev_err(dev, "MSI controller not supported\n");
+		return -ENODEV;
+	}
+
 	dev_set_msi_domain(epc->dev.parent, dom);
 
 	msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);

-- 
2.34.1