[PATCH v18 08/15] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check

Frank Li
2025-04-14T18:32:05Z

Some MSI controller change address/data pair when irq_set_affinity().
Current PCI endpoint can't support this type MSI controller. So add flag
MSI_FLAG_MUTABLE in include/linux/msi.h and check it when allocate
doorbell.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change from v14 to v16
- 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;
+
+ if (!irq_domain_is_msi_immutable(dom)) {
+ dev_err(dev, "Can't support mutable address/data pair MSI controller\n");
+ return -EINVAL;
+ }
+
msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);
if (!msg)
return -ENOMEM;

--
2.34.1