powerpc/powernv: Rework exports to support subnodes

Originally we only had a handful of exported memory ranges, but we'd to
export the per-core trace buffers. This results in a lot of files in the
exports directory which is a but unfortunate. We can clean things up a bit
by turning subnodes into subdirectories of the exports directory.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-1-oohall@gmail.com

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index a6ee080..1434856 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -834,6 +834,75 @@ static ssize_t export_attr_read(struct file *fp, struct kobject *kobj,
                                       bin_attr->size);
 }
 
+static int opal_add_one_export(struct kobject *parent, const char *export_name,
+                              struct device_node *np, const char *prop_name)
+{
+       struct bin_attribute *attr = NULL;
+       const char *name = NULL;
+       u64 vals[2];
+       int rc;
+
+       rc = of_property_read_u64_array(np, prop_name, &vals[0], 2);
+       if (rc)
+               goto out;
+
+       attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+       name = kstrdup(export_name, GFP_KERNEL);
+       if (!name) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       sysfs_bin_attr_init(attr);
+       attr->attr.name = name;
+       attr->attr.mode = 0400;
+       attr->read = export_attr_read;
+       attr->private = __va(vals[0]);
+       attr->size = vals[1];
+
+       rc = sysfs_create_bin_file(parent, attr);
+out:
+       if (rc) {
+               kfree(name);
+               kfree(attr);
+       }
+
+       return rc;
+}
+
+static void opal_add_exported_attrs(struct device_node *np,
+                                   struct kobject *kobj)
+{
+       struct device_node *child;
+       struct property *prop;
+
+       for_each_property_of_node(np, prop) {
+               int rc;
+
+               if (!strcmp(prop->name, "name") ||
+                   !strcmp(prop->name, "phandle"))
+                       continue;
+
+               rc = opal_add_one_export(kobj, prop->name, np, prop->name);
+               if (rc) {
+                       pr_warn("Unable to add export %pOF/%s, rc = %d!\n",
+                               np, prop->name, rc);
+               }
+       }
+
+       for_each_child_of_node(np, child) {
+               struct kobject *child_kobj;
+
+               child_kobj = kobject_create_and_add(child->name, kobj);
+               if (!child_kobj) {
+                       pr_err("Unable to create export dir for %pOF\n", child);
+                       continue;
+               }
+
+               opal_add_exported_attrs(child, child_kobj);
+       }
+}
+
 /*
  * opal_export_attrs: creates a sysfs node for each property listed in
  * the device-tree under /ibm,opal/firmware/exports/
@@ -843,12 +912,8 @@ static ssize_t export_attr_read(struct file *fp, struct kobject *kobj,
  */
 static void opal_export_attrs(void)
 {
-       struct bin_attribute *attr;
        struct device_node *np;
-       struct property *prop;
        struct kobject *kobj;
-       u64 vals[2];
-       int rc;
 
        np = of_find_node_by_path("/ibm,opal/firmware/exports");
        if (!np)
@@ -861,41 +926,7 @@ static void opal_export_attrs(void)
                return;
        }
 
-       for_each_property_of_node(np, prop) {
-               if (!strcmp(prop->name, "name") || !strcmp(prop->name, "phandle"))
-                       continue;
-
-               if (of_property_read_u64_array(np, prop->name, &vals[0], 2))
-                       continue;
-
-               attr = kzalloc(sizeof(*attr), GFP_KERNEL);
-
-               if (attr == NULL) {
-                       pr_warn("Failed kmalloc for bin_attribute!");
-                       continue;
-               }
-
-               sysfs_bin_attr_init(attr);
-               attr->attr.name = kstrdup(prop->name, GFP_KERNEL);
-               attr->attr.mode = 0400;
-               attr->read = export_attr_read;
-               attr->private = __va(vals[0]);
-               attr->size = vals[1];
-
-               if (attr->attr.name == NULL) {
-                       pr_warn("Failed kstrdup for bin_attribute attr.name");
-                       kfree(attr);
-                       continue;
-               }
-
-               rc = sysfs_create_bin_file(kobj, attr);
-               if (rc) {
-                       pr_warn("Error %d creating OPAL sysfs exports/%s file\n",
-                                rc, prop->name);
-                       kfree(attr->attr.name);
-                       kfree(attr);
-               }
-       }
+       opal_add_exported_attrs(np, kobj);
 
        of_node_put(np);
 }
@@ -1056,11 +1087,10 @@ static int __init opal_init(void)
                opal_sys_param_init();
                /* Setup message log sysfs interface. */
                opal_msglog_sysfs_init();
+               /* Add all export properties*/
+               opal_export_attrs();
        }
 
-       /* Export all properties */
-       opal_export_attrs();
-
        /* Initialize platform devices: IPMI backend, PRD & flash interface */
        opal_pdev_init("ibm,opal-ipmi");
        opal_pdev_init("ibm,opal-flash");