5 files changed, 61 insertions, 0 deletions
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 45e7e044cf4a..f470ef5c0a6a 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -73,6 +73,7 @@ struct cxl_rcrb_info;
 resource_size_t __rcrb_to_component(struct device *dev,
 				    struct cxl_rcrb_info *ri,
 				    enum cxl_rcrb which);
+u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb);
 
 extern struct rw_semaphore cxl_dpa_rwsem;
 
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index c7a7887ebdcf..cbccc222bb91 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -718,6 +718,21 @@ static bool cxl_report_and_clear(struct cxl_dev_state *cxlds)
 	return true;
 }
 
+#ifdef CONFIG_PCIEAER_CXL
+
+void cxl_setup_parent_dport(struct device *host, struct cxl_dport *dport)
+{
+	struct device *dport_dev = dport->dport_dev;
+	struct pci_host_bridge *host_bridge;
+
+	host_bridge = to_pci_host_bridge(dport_dev);
+	if (host_bridge->native_cxl_error)
+		dport->rcrb.aer_cap = cxl_rcrb_to_aer(dport_dev, dport->rcrb.base);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_setup_parent_dport, CXL);
+
+#endif
+
 pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
 				    pci_channel_state_t state)
 {
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index e0fbe964f6f0..9111ceef1127 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -470,6 +470,42 @@ int cxl_setup_regs(struct cxl_register_map *map)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_setup_regs, CXL);
 
+u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb)
+{
+	void __iomem *addr;
+	u16 offset = 0;
+	u32 cap_hdr;
+
+	if (WARN_ON_ONCE(rcrb == CXL_RESOURCE_NONE))
+		return 0;
+
+	if (!request_mem_region(rcrb, SZ_4K, dev_name(dev)))
+		return 0;
+
+	addr = ioremap(rcrb, SZ_4K);
+	if (!addr)
+		goto out;
+
+	cap_hdr = readl(addr + offset);
+	while (PCI_EXT_CAP_ID(cap_hdr) != PCI_EXT_CAP_ID_ERR) {
+		offset = PCI_EXT_CAP_NEXT(cap_hdr);
+
+		/* Offset 0 terminates capability list. */
+		if (!offset)
+			break;
+		cap_hdr = readl(addr + offset);
+	}
+
+	if (offset)
+		dev_dbg(dev, "found AER extended capability (0x%x)\n", offset);
+
+	iounmap(addr);
+out:
+	release_mem_region(rcrb, SZ_4K);
+
+	return offset;
+}
+
 resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri,
 				    enum cxl_rcrb which)
 {
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index c07064e0c136..cdb2ade6ba29 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -704,6 +704,13 @@ struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
 					 struct device *dport_dev, int port_id,
 					 resource_size_t rcrb);
 
+#ifdef CONFIG_PCIEAER_CXL
+void cxl_setup_parent_dport(struct device *host, struct cxl_dport *dport);
+#else
+static inline void cxl_setup_parent_dport(struct device *host,
+					  struct cxl_dport *dport) { }
+#endif
+
 struct cxl_decoder *to_cxl_decoder(struct device *dev);
 struct cxl_root_decoder *to_cxl_root_decoder(struct device *dev);
 struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev);
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 04107058739b..e087febf9af0 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -157,6 +157,8 @@ static int cxl_mem_probe(struct device *dev)
 	else
 		endpoint_parent = &parent_port->dev;
 
+	cxl_setup_parent_dport(dev, dport);
+
 	device_lock(endpoint_parent);
 	if (!endpoint_parent->driver) {
 		dev_err(dev, "CXL port topology %s not enabled\n",