[PATCH v5 15/16] cxl/pci: Add support to assign and clear pci_driver::cxl_err_handlers

Terry Bowman
2025-01-07T14:41:57Z

pci_driver::cxl_err_handlers are not currently assigned handler callbacks.
The handlers can't be set in the pci_driver static definition because the
CXL PCIe Port devices are bound to the portdrv driver which is not CXL
driver aware.

Add cxl_assign_port_error_handlers() in the cxl_core module. This
function will assign the default handlers for a CXL PCIe Port device.

When the CXL Port (cxl_port or cxl_dport) is destroyed the device's
pci_driver::cxl_err_handlers must be set to NULL indicating they should no
longer be used.

Create cxl_clear_port_error_handlers() and register it to be called
when the CXL Port device (cxl_port or cxl_dport) is destroyed.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
---
drivers/cxl/core/pci.c | 49 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 3e87fe54a1a2..9c162120f0fe 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -848,8 +848,40 @@ static bool cxl_port_error_detected(struct pci_dev *pdev)
return __cxl_handle_ras(&pdev->dev, ras_base);
}

+static const struct cxl_error_handlers cxl_port_error_handlers = {
+ .error_detected = cxl_port_error_detected,
+ .cor_error_detected = cxl_port_cor_error_detected,
+};
+
+static void cxl_assign_port_error_handlers(struct pci_dev *pdev)
+{
+ struct pci_driver *pdrv;
+
+ if (!pdev || !pdev->driver || !get_device(&pdev->dev))
+ return;
+
+ pdrv = pdev->driver;
+ pdrv->cxl_err_handler = &cxl_port_error_handlers;
+ put_device(&pdev->dev);
+}
+
+static void cxl_clear_port_error_handlers(void *data)
+{
+ struct pci_dev *pdev = data;
+ struct pci_driver *pdrv;
+
+ if (!pdev || !pdev->driver || !get_device(&pdev->dev))
+ return;
+
+ pdrv = pdev->driver;
+ pdrv->cxl_err_handler = NULL;
+ put_device(&pdev->dev);
+}
+
void cxl_uport_init_ras_reporting(struct cxl_port *port)
{
+ struct pci_dev *pdev = to_pci_dev(port->uport_dev);
+
/* uport may have more than 1 downstream EP. Check if already mapped. */
if (port->uport_regs.ras)
return;
@@ -860,6 +892,9 @@ void cxl_uport_init_ras_reporting(struct cxl_port *port)
dev_err(&port->dev, "Failed to map RAS capability.\n");
return;
}
+
+ cxl_assign_port_error_handlers(pdev);
+ devm_add_action_or_reset(&port->dev, cxl_clear_port_error_handlers, pdev);
}
EXPORT_SYMBOL_NS_GPL(cxl_uport_init_ras_reporting, "CXL");

@@ -871,6 +906,8 @@ void cxl_dport_init_ras_reporting(struct cxl_dport *dport)
{
struct device *dport_dev = dport->dport_dev;
struct pci_host_bridge *host_bridge = to_pci_host_bridge(dport_dev);
+ struct pci_dev *pdev = to_pci_dev(dport_dev);
+ struct cxl_port *port;

dport->reg_map.host = dport_dev;
if (dport->rch && host_bridge->native_aer) {
@@ -887,6 +924,18 @@ void cxl_dport_init_ras_reporting(struct cxl_dport *dport)
dev_err(dport_dev, "Failed to map RAS capability.\n");
return;
}
+
+ if (dport->rch)
+ return;
+
+ port = find_cxl_port(dport_dev, NULL);
+ if (!port) {
+ dev_err(dport_dev, "Failed to find upstream port\n");
+ return;
+ }
+ cxl_assign_port_error_handlers(pdev);
+ devm_add_action_or_reset(&port->dev, cxl_clear_port_error_handlers, pdev);
+ put_device(&port->dev);
}
EXPORT_SYMBOL_NS_GPL(cxl_dport_init_ras_reporting, "CXL");

--
2.34.1