[PATCH v2 10/14] cxl/pci: Map CXL PCIe upstream switch port RAS registers

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

Add logic to map CXL PCIe upstream switch port (USP) RAS registers.

Introduce 'struct cxl_regs' member into 'struct cxl_port' to store a
pointer to the upstream port's mapped RAS registers.

The upstream port may have multiple downstream endpoints. Before
mapping AER registers check if the registers are already mapped.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
---
 drivers/cxl/core/pci.c | 17 +++++++++++++++++
 drivers/cxl/cxl.h      |  4 ++++
 drivers/cxl/mem.c      |  3 +++
 3 files changed, 24 insertions(+)

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 0bb61e39cf8f..53ca773557f3 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -773,6 +773,23 @@ static void cxl_disable_rch_root_ints(struct cxl_dport *dport)
 	writel(aer_cmd, aer_base + PCI_ERR_ROOT_COMMAND);
 }
 
+void cxl_uport_init_ras_reporting(struct cxl_port *port)
+{
+	/* uport may have more than 1 downstream EP. Check if already mapped. */
+	if (port->uport_regs.ras) {
+		dev_warn(&port->dev, "RAS is already mapped\n");
+		return;
+	}
+
+	port->reg_map.host = &port->dev;
+	if (cxl_map_component_regs(&port->reg_map, &port->uport_regs,
+				   BIT(CXL_CM_CAP_CAP_ID_RAS))) {
+		dev_err(&port->dev, "Failed to map RAS capability.\n");
+		return;
+	}
+}
+EXPORT_SYMBOL_NS_GPL(cxl_uport_init_ras_reporting, CXL);
+
 /**
  * cxl_dport_init_ras_reporting - Setup CXL RAS report on this dport
  * @dport: the cxl_dport that needs to be initialized
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 787688e81602..ded6a343c05e 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -592,6 +592,7 @@ struct cxl_dax_region {
  * @parent_dport: dport that points to this port in the parent
  * @decoder_ida: allocator for decoder ids
  * @reg_map: component and ras register mapping parameters
+ * @uport_regs: mapped component registers
  * @nr_dports: number of entries in @dports
  * @hdm_end: track last allocated HDM decoder instance for allocation ordering
  * @commit_end: cursor to track highest committed decoder for commit ordering
@@ -612,6 +613,7 @@ struct cxl_port {
 	struct cxl_dport *parent_dport;
 	struct ida decoder_ida;
 	struct cxl_register_map reg_map;
+	struct cxl_component_regs uport_regs;
 	int nr_dports;
 	int hdm_end;
 	int commit_end;
@@ -763,8 +765,10 @@ struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
 
 #ifdef CONFIG_PCIEAER_CXL
 void cxl_dport_init_ras_reporting(struct cxl_dport *dport);
+void cxl_uport_init_ras_reporting(struct cxl_port *port);
 #else
 static inline void cxl_dport_init_ras_reporting(struct cxl_dport *dport) { }
+static inline void cxl_uport_init_ras_reporting(struct cxl_port *port) { }
 #endif
 
 struct cxl_decoder *to_cxl_decoder(struct device *dev);
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 240d54b22a8c..067fd6389562 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -66,6 +66,9 @@ static void cxl_init_ep_ports_aer(struct cxl_ep *ep)
 	if (dev_is_cxl_pci(dport->dport_dev, PCI_EXP_TYPE_DOWNSTREAM) ||
 	    dev_is_cxl_pci(dport->dport_dev, PCI_EXP_TYPE_ROOT_PORT))
 		cxl_dport_init_ras_reporting(dport);
+
+	if (dev_is_cxl_pci(dport->port->uport_dev, PCI_EXP_TYPE_UPSTREAM))
+		cxl_uport_init_ras_reporting(dport->port);
 }
 
 static int devm_cxl_add_endpoint(struct device *host, struct cxl_memdev *cxlmd,
-- 
2.34.1