The port scanning algorithm in devm_cxl_enumerate_ports() walks up the topology and adds cxl_port objects starting from the root down to the endpoint. When those ports are initially created they know all their dports, but they do not know the downstream cxl_port instance that represents the next descendant in the topology. Rework create_endpoint() into devm_cxl_add_endpoint() that enumerates the downstream cxl_port topology into each port's 'struct cxl_ep' record for each endpoint it that the port is an ancestor. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220624041950.559155-7-dan.j.williams@xxxxxxxxx Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- drivers/cxl/core/port.c | 41 +++++++++++++++++++++++++++++++++++++++++ drivers/cxl/cxl.h | 5 +++++ drivers/cxl/mem.c | 30 +----------------------------- 3 files changed, 47 insertions(+), 29 deletions(-) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index a43735f349d6..4907db798ad9 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1087,6 +1087,47 @@ static struct cxl_ep *cxl_ep_load(struct cxl_port *port, return xa_load(&port->endpoints, (unsigned long)&cxlmd->dev); } +int devm_cxl_add_endpoint(struct cxl_memdev *cxlmd, + struct cxl_dport *parent_dport) +{ + struct cxl_port *parent_port = parent_dport->port; + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_port *endpoint, *iter, *down; + int rc; + + /* + * Now that the path to the root is established record all the + * intervening ports in the chain. + */ + for (iter = parent_port, down = NULL; !is_cxl_root(iter); + down = iter, iter = to_cxl_port(iter->dev.parent)) { + struct cxl_ep *ep; + + ep = cxl_ep_load(iter, cxlmd); + ep->next = down; + } + + endpoint = devm_cxl_add_port(&parent_port->dev, &cxlmd->dev, + cxlds->component_reg_phys, parent_dport); + if (IS_ERR(endpoint)) + return PTR_ERR(endpoint); + + dev_dbg(&cxlmd->dev, "add: %s\n", dev_name(&endpoint->dev)); + + rc = cxl_endpoint_autoremove(cxlmd, endpoint); + if (rc) + return rc; + + if (!endpoint->dev.driver) { + dev_err(&cxlmd->dev, "%s failed probe\n", + dev_name(&endpoint->dev)); + return -ENXIO; + } + + return 0; +} +EXPORT_SYMBOL_NS_GPL(devm_cxl_add_endpoint, CXL); + static void cxl_detach_ep(void *data) { struct cxl_memdev *cxlmd = data; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index bf5f0c305115..a108d5c288ca 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -378,10 +378,13 @@ struct cxl_dport { * struct cxl_ep - track an endpoint's interest in a port * @ep: device that hosts a generic CXL endpoint (expander or accelerator) * @dport: which dport routes to this endpoint on @port + * @next: cxl switch port across the link attached to @dport NULL if + * attached to an endpoint */ struct cxl_ep { struct device *ep; struct cxl_dport *dport; + struct cxl_port *next; }; /* @@ -404,6 +407,8 @@ struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port); struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, resource_size_t component_reg_phys, struct cxl_dport *parent_dport); +int devm_cxl_add_endpoint(struct cxl_memdev *cxlmd, + struct cxl_dport *parent_dport); struct cxl_port *find_cxl_root(struct device *dev); int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); int cxl_bus_rescan(void); diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 2786d3402c9e..64ccf053d32c 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -25,34 +25,6 @@ * in higher level operations. */ -static int create_endpoint(struct cxl_memdev *cxlmd, - struct cxl_dport *parent_dport) -{ - struct cxl_port *parent_port = parent_dport->port; - struct cxl_dev_state *cxlds = cxlmd->cxlds; - struct cxl_port *endpoint; - int rc; - - endpoint = devm_cxl_add_port(&parent_port->dev, &cxlmd->dev, - cxlds->component_reg_phys, parent_dport); - if (IS_ERR(endpoint)) - return PTR_ERR(endpoint); - - dev_dbg(&cxlmd->dev, "add: %s\n", dev_name(&endpoint->dev)); - - rc = cxl_endpoint_autoremove(cxlmd, endpoint); - if (rc) - return rc; - - if (!endpoint->dev.driver) { - dev_err(&cxlmd->dev, "%s failed probe\n", - dev_name(&endpoint->dev)); - return -ENXIO; - } - - return 0; -} - static void enable_suspend(void *data) { cxl_mem_active_dec(); @@ -116,7 +88,7 @@ static int cxl_mem_probe(struct device *dev) goto unlock; } - rc = create_endpoint(cxlmd, dport); + rc = devm_cxl_add_endpoint(cxlmd, dport); unlock: device_unlock(&parent_port->dev); put_device(&parent_port->dev);
