[PATCH v10 16/17] CXL/PCI: Enable CXL protocol errors during CXL Port probe

[Terry Bowman <terry.bowman@xxxxxxx>]

CXL protocol errors are not enabled for all CXL devices after boot. These
must be enabled inorder to process CXL protocol errors.

Export the AER service driver's pci_aer_unmask_internal_errors().

Introduce cxl_unmask_proto_interrupts() to call pci_aer_unmask_internal_errors().
pci_aer_unmask_internal_errors() expects the pdev->aer_cap is initialized.
But, dev->aer_cap is not initialized for CXL Upstream Switch Ports and CXL
Downstream Switch Ports. Initialize the dev->aer_cap if necessary. Enable AER
correctable internal errors and uncorrectable internal errors for all CXL
devices.

Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
---
 drivers/cxl/port.c         | 29 +++++++++++++++++++++++++++--
 drivers/pci/pcie/cxl_aer.c |  3 ++-
 include/linux/aer.h        |  1 +
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index b52f82925891..b90f5efa5904 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -3,6 +3,7 @@
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/pci.h>
 
 #include "cxlmem.h"
 #include "cxlpci.h"
@@ -60,6 +61,21 @@ static int discover_region(struct device *dev, void *unused)
 
 #ifdef CONFIG_PCIEAER_CXL
 
+static void cxl_unmask_proto_interrupts(struct device *dev)
+{
+	struct pci_dev *pdev __free(pci_dev_put) =
+		pci_dev_get(to_pci_dev(dev));
+
+	if (!pdev->aer_cap) {
+		pdev->aer_cap = pci_find_ext_capability(pdev,
+							PCI_EXT_CAP_ID_ERR);
+		if (!pdev->aer_cap)
+			return;
+	}
+
+	pci_aer_unmask_internal_errors(pdev);
+}
+
 static void cxl_dport_map_rch_aer(struct cxl_dport *dport)
 {
 	resource_size_t aer_phys;
@@ -118,8 +134,12 @@ static void cxl_uport_init_ras_reporting(struct cxl_port *port,
 
 	map->host = host;
 	if (cxl_map_component_regs(map, &port->uport_regs,
-				   BIT(CXL_CM_CAP_CAP_ID_RAS)))
+				   BIT(CXL_CM_CAP_CAP_ID_RAS))) {
 		dev_dbg(&port->dev, "Failed to map RAS capability\n");
+		return;
+	}
+
+	cxl_unmask_proto_interrupts(port->uport_dev);
 }
 
 /**
@@ -144,9 +164,12 @@ void cxl_dport_init_ras_reporting(struct cxl_dport *dport, struct device *host)
 	}
 
 	if (cxl_map_component_regs(&dport->reg_map, &dport->regs.component,
-				   BIT(CXL_CM_CAP_CAP_ID_RAS)))
+				   BIT(CXL_CM_CAP_CAP_ID_RAS))) {
 		dev_dbg(dport->dport_dev, "Failed to map RAS capability\n");
+		return;
+	}
 
+	cxl_unmask_proto_interrupts(dport->dport_dev);
 }
 EXPORT_SYMBOL_NS_GPL(cxl_dport_init_ras_reporting, "CXL");
 
@@ -180,6 +203,8 @@ static void cxl_endpoint_port_init_ras(struct cxl_port *port)
 	}
 
 	cxl_dport_init_ras_reporting(dport, cxlmd->cxlds->dev);
+
+	cxl_unmask_proto_interrupts(cxlmd->cxlds->dev);
 }
 
 #else
diff --git a/drivers/pci/pcie/cxl_aer.c b/drivers/pci/pcie/cxl_aer.c
index 38dc82df0baf..3c5bf162607c 100644
--- a/drivers/pci/pcie/cxl_aer.c
+++ b/drivers/pci/pcie/cxl_aer.c
@@ -18,7 +18,7 @@
  * Note: AER must be enabled and supported by the device which must be
  * checked in advance, e.g. with pcie_aer_is_native().
  */
-static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
+void pci_aer_unmask_internal_errors(struct pci_dev *dev)
 {
 	int aer = dev->aer_cap;
 	u32 mask;
@@ -31,6 +31,7 @@ static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
 	mask &= ~PCI_ERR_COR_INTERNAL;
 	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, mask);
 }
+EXPORT_SYMBOL_NS_GPL(pci_aer_unmask_internal_errors, "CXL");
 
 static bool is_cxl_mem_dev(struct pci_dev *dev)
 {
diff --git a/include/linux/aer.h b/include/linux/aer.h
index f14db635ef90..8fb1eca97c37 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -113,5 +113,6 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
 int cper_severity_to_aer(int cper_severity);
 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
 		       int severity, struct aer_capability_regs *aer_regs);
+void pci_aer_unmask_internal_errors(struct pci_dev *dev);
 #endif //_AER_H_
 
-- 
2.34.1