[PATCH v15 9/9] cxl: Enable CXL protocol error reporting

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

CXL protocol errors are not enabled for all CXL devices after boot. These
must be enabled inorder to process CXL protocol 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@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>

---

Changes in v13->v14:
- Update commit title's prefix (Bjorn)

Changes in v12->v13:
- Add dev and dev_is_pci() NULL checks in cxl_unmask_proto_interrupts() (Terry)
- Add Dave Jiang's and Ben's review-by

Changes in v11->v12:
- None

Changes in v10->v11:
- Added check for valid PCI devices in is_cxl_error() (Terry)
- Removed check for RCiEP in cxl_handle_proto_err() and
  cxl_report_error_detected() (Terry)
---
 drivers/cxl/core/port.c |  2 ++
 drivers/cxl/core/ras.c  | 22 ++++++++++++++++++++++
 drivers/cxl/cxlpci.h    |  4 ++++
 3 files changed, 28 insertions(+)

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 8e30a3e7f610..b63e8117d937 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1870,6 +1870,8 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)
 
 			rc = cxl_add_ep(dport, &cxlmd->dev);
 
+			cxl_unmask_proto_interrupts(cxlmd->cxlds->dev);
+
 			/*
 			 * If the endpoint already exists in the port's list,
 			 * that's ok, it was added on a previous pass.
diff --git a/drivers/cxl/core/ras.c b/drivers/cxl/core/ras.c
index e5a0d0283d3f..d6c2fd4ae067 100644
--- a/drivers/cxl/core/ras.c
+++ b/drivers/cxl/core/ras.c
@@ -118,6 +118,24 @@ static void cxl_cper_prot_err_work_fn(struct work_struct *work)
 }
 static DECLARE_WORK(cxl_cper_prot_err_work, cxl_cper_prot_err_work_fn);
 
+void cxl_unmask_proto_interrupts(struct device *dev)
+{
+	if (!dev || !dev_is_pci(dev))
+		return;
+
+	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);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_unmask_proto_interrupts, "CXL");
+
 static void cxl_dport_map_ras(struct cxl_dport *dport)
 {
 	struct cxl_register_map *map = &dport->reg_map;
@@ -128,6 +146,8 @@ static void cxl_dport_map_ras(struct cxl_dport *dport)
 	else if (cxl_map_component_regs(map, &dport->regs.component,
 					BIT(CXL_CM_CAP_CAP_ID_RAS)))
 		dev_dbg(dev, "Failed to map RAS capability.\n");
+
+	cxl_unmask_proto_interrupts(dev);
 }
 
 /**
@@ -171,6 +191,8 @@ void devm_cxl_port_ras_setup(struct cxl_port *port)
 	if (cxl_map_component_regs(map, &port->regs,
 				   BIT(CXL_CM_CAP_CAP_ID_RAS)))
 		dev_dbg(&port->dev, "Failed to map RAS capability\n");
+
+	cxl_unmask_proto_interrupts(port->uport_dev);
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_port_ras_setup, "CXL");
 
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index e3388dffdd75..b5fea624b2cc 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -82,6 +82,7 @@ void devm_cxl_dport_rch_ras_setup(struct cxl_dport *dport);
 pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
 					pci_channel_state_t error);
 void devm_cxl_port_ras_setup(struct cxl_port *port);
+void cxl_unmask_proto_interrupts(struct device *dev);
 #else
 static inline pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
 						      pci_channel_state_t state)
@@ -94,6 +95,9 @@ static inline void devm_cxl_dport_rch_ras_setup(struct cxl_dport *dport)
 static inline void devm_cxl_port_ras_setup(struct cxl_port *port)
 {
 }
+static inline void cxl_unmask_proto_interrupts(struct device *dev)
+{
+}
 #endif
 
 #endif /* __CXL_PCI_H__ */
-- 
2.34.1