Some MSI controllers can change address/data pair during the execution of
irq_chip::irq_set_affinity() callback. Since the current PCI Endpoint
framework cannot support mutable MSI controllers, call
irq_domain_is_msi_immutable() API to check if the controller is immutable
or not.
Also ensure that the MSI domain is a parent MSI domain so that it can
allocate address/data pairs.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[mani: reworded error message and commit message]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Niklas Cassel <cassel@kernel.org>
Link: https://patch.msgid.link/20250710-ep-msi-v21-4-57683fc7fb25@nxp.com
Implement the doorbell feature by mapping the EP's MSI interrupt controller
message address to a dedicated BAR.
The EPF driver should pass the actual message data to be written to the
message address by the host through implementation-specific logic.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[mani: minor code cleanups and reworded commit message]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: fix kernel-doc]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Niklas Cassel <cassel@kernel.org>
Link: https://patch.msgid.link/20250710-ep-msi-v21-3-57683fc7fb25@nxp.com
