cxl/port: Refactor __devm_cxl_add_port() to drop goto pattern

In __devm_cxl_add_port(), there is a 'goto' to call put_device() for the
error cases between device_initialize() and device_add() to dereference
the 'struct device' of a new cxl_port. The 'goto' pattern in the case
can be removed by refactoring. Introducing a new function called
cxl_port_add() which is used to add the 'struct device' of a new
cxl_port to device hierarchy, moving the functions needing the help of
the 'goto' into cxl_port_add(), and using a scoped-based resource
management __free() to drop the open coded put_device() and the 'goto'
for the error cases.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Li Ming <ming4.li@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huwaei.com>
Link: https://patch.msgid.link/20240830013138.2256244-3-ming4.li@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index ebd7ddadbb544f7417af498c0ad0c22a8ef9eea6..7ca57285a7b757941937e2fec589e11c6cc57e56 100644 (file)
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -828,27 +828,20 @@ static void cxl_debugfs_create_dport_dir(struct cxl_dport *dport)
                            &cxl_einj_inject_fops);
 }
 
-static struct cxl_port *__devm_cxl_add_port(struct device *host,
-                                           struct device *uport_dev,
-                                           resource_size_t component_reg_phys,
-                                           struct cxl_dport *parent_dport)
+static int cxl_port_add(struct cxl_port *port,
+                       resource_size_t component_reg_phys,
+                       struct cxl_dport *parent_dport)
 {
-       struct cxl_port *port;
-       struct device *dev;
+       struct device *dev __free(put_device) = &port->dev;
        int rc;
 
-       port = cxl_port_alloc(uport_dev, parent_dport);
-       if (IS_ERR(port))
-               return port;
-
-       dev = &port->dev;
-       if (is_cxl_memdev(uport_dev)) {
-               struct cxl_memdev *cxlmd = to_cxl_memdev(uport_dev);
+       if (is_cxl_memdev(port->uport_dev)) {
+               struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
                struct cxl_dev_state *cxlds = cxlmd->cxlds;
 
                rc = dev_set_name(dev, "endpoint%d", port->id);
                if (rc)
-                       goto err;
+                       return rc;
 
                /*
                 * The endpoint driver already enumerated the component and RAS
@@ -861,19 +854,41 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
        } else if (parent_dport) {
                rc = dev_set_name(dev, "port%d", port->id);
                if (rc)
-                       goto err;
+                       return rc;
 
                rc = cxl_port_setup_regs(port, component_reg_phys);
                if (rc)
-                       goto err;
-       } else
+                       return rc;
+       } else {
                rc = dev_set_name(dev, "root%d", port->id);
-       if (rc)
-               goto err;
+               if (rc)
+                       return rc;
+       }
 
        rc = device_add(dev);
        if (rc)
-               goto err;
+               return rc;
+
+       /* Inhibit the cleanup function invoked */
+       dev = NULL;
+       return 0;
+}
+
+static struct cxl_port *__devm_cxl_add_port(struct device *host,
+                                           struct device *uport_dev,
+                                           resource_size_t component_reg_phys,
+                                           struct cxl_dport *parent_dport)
+{
+       struct cxl_port *port;
+       int rc;
+
+       port = cxl_port_alloc(uport_dev, parent_dport);
+       if (IS_ERR(port))
+               return port;
+
+       rc = cxl_port_add(port, component_reg_phys, parent_dport);
+       if (rc)
+               return ERR_PTR(rc);
 
        rc = devm_add_action_or_reset(host, unregister_port, port);
        if (rc)
@@ -891,10 +906,6 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
                port->pci_latency = cxl_pci_get_latency(to_pci_dev(uport_dev));
 
        return port;
-
-err:
-       put_device(dev);
-       return ERR_PTR(rc);
 }
 
 /**