[RFC PATCH 1/9] PCI/AER: Update AER driver to call root port and downstream port UCE handlers

[Terry Bowman <terry.bowman@amd.com>]

The AER service driver does not currently call a handler for AER
uncorrectable errors (UCE) detected in root ports or downstream
ports. This is not needed in most cases because common PCIe port
functionality is handled by portdrv service drivers.

CXL root ports include CXL specific RAS registers that need logging
before starting do_recovery() in the UCE case.

Update the AER service driver to call the UCE handler for root ports
and downstream ports. These PCIe port devices are bound to the portdrv
driver that includes a CE and UCE handler to be called.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
---
 drivers/pci/pcie/err.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 705893b5f7b0..a4db474b2be5 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -203,6 +203,26 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
 
+	/*
+	 * PCIe ports may include functionality beyond the standard
+	 * extended port capabilities. This may present a need to log and
+	 * handle errors not addressed in this driver. Examples are CXL
+	 * root ports and CXL downstream switch ports using AER UIE to
+	 * indicate CXL UCE RAS protocol errors.
+	 */
+	if (type == PCI_EXP_TYPE_ROOT_PORT ||
+	    type == PCI_EXP_TYPE_DOWNSTREAM) {
+		struct pci_driver *pdrv = dev->driver;
+
+		if (pdrv && pdrv->err_handler &&
+		    pdrv->err_handler->error_detected) {
+			const struct pci_error_handlers *err_handler;
+
+			err_handler = pdrv->err_handler;
+			status = err_handler->error_detected(dev, state);
+		}
+	}
+
 	/*
 	 * If the error was detected by a Root Port, Downstream Port, RCEC,
 	 * or RCiEP, recovery runs on the device itself.  For Ports, that
-- 
2.34.1