ACPI / property: Expose data-only subnodes via sysfs

Add infrastructure needed to expose data-only subnodes of ACPI
device objects introduced previously via sysfs.

Each data-only subnode is represented as a sysfs directory under
the directory corresponding to its parent object (a device or a
data-only subnode).  Each of them has a "path" attribute (containing
the full ACPI namespace path to the object the subnode data come from)
at this time.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index 4ab4582e586b750a287b8b6744ecb3e0f480593f..707cf6213bc2888b4cc1e09a0f851d232b9521c0 100644 (file)
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -26,6 +26,106 @@
 
 #include "internal.h"
 
+static ssize_t acpi_object_path(acpi_handle handle, char *buf)
+{
+       struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
+       int result;
+
+       result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
+       if (result)
+               return result;
+
+       result = sprintf(buf, "%s\n", (char*)path.pointer);
+       kfree(path.pointer);
+       return result;
+}
+
+struct acpi_data_node_attr {
+       struct attribute attr;
+       ssize_t (*show)(struct acpi_data_node *, char *);
+       ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
+};
+
+#define DATA_NODE_ATTR(_name)                  \
+       static struct acpi_data_node_attr data_node_##_name =   \
+               __ATTR(_name, 0444, data_node_show_##_name, NULL)
+
+static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
+{
+       return acpi_object_path(dn->handle, buf);
+}
+
+DATA_NODE_ATTR(path);
+
+static struct attribute *acpi_data_node_default_attrs[] = {
+       &data_node_path.attr,
+       NULL
+};
+
+#define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
+#define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
+
+static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
+                                       struct attribute *attr, char *buf)
+{
+       struct acpi_data_node *dn = to_data_node(kobj);
+       struct acpi_data_node_attr *dn_attr = to_attr(attr);
+
+       return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
+}
+
+static const struct sysfs_ops acpi_data_node_sysfs_ops = {
+       .show   = acpi_data_node_attr_show,
+};
+
+static void acpi_data_node_release(struct kobject *kobj)
+{
+       struct acpi_data_node *dn = to_data_node(kobj);
+       complete(&dn->kobj_done);
+}
+
+static struct kobj_type acpi_data_node_ktype = {
+       .sysfs_ops = &acpi_data_node_sysfs_ops,
+       .default_attrs = acpi_data_node_default_attrs,
+       .release = acpi_data_node_release,
+};
+
+static void acpi_expose_nondev_subnodes(struct kobject *kobj,
+                                       struct acpi_device_data *data)
+{
+       struct list_head *list = &data->subnodes;
+       struct acpi_data_node *dn;
+
+       if (list_empty(list))
+               return;
+
+       list_for_each_entry(dn, list, sibling) {
+               int ret;
+
+               init_completion(&dn->kobj_done);
+               ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
+                                          kobj, dn->name);
+               if (ret)
+                       acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
+               else
+                       acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
+       }
+}
+
+static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
+{
+       struct list_head *list = &data->subnodes;
+       struct acpi_data_node *dn;
+
+       if (list_empty(list))
+               return;
+
+       list_for_each_entry_reverse(dn, list, sibling) {
+               acpi_hide_nondev_subnodes(&dn->data);
+               kobject_put(&dn->kobj);
+       }
+}
+
 /**
  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
  * @acpi_dev: ACPI device object.
@@ -323,20 +423,12 @@ static ssize_t acpi_device_adr_show(struct device *dev,
 }
 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
 
-static ssize_t
-acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
+static ssize_t acpi_device_path_show(struct device *dev,
+                                    struct device_attribute *attr, char *buf)
+{
        struct acpi_device *acpi_dev = to_acpi_device(dev);
-       struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
-       int result;
-
-       result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
-       if (result)
-               goto end;
 
-       result = sprintf(buf, "%s\n", (char*)path.pointer);
-       kfree(path.pointer);
-end:
-       return result;
+       return acpi_object_path(acpi_dev->handle, buf);
 }
 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
 
@@ -475,6 +567,8 @@ int acpi_device_setup_files(struct acpi_device *dev)
                                                    &dev_attr_real_power_state);
        }
 
+       acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
+
 end:
        return result;
 }
@@ -485,6 +579,8 @@ end:
  */
 void acpi_device_remove_files(struct acpi_device *dev)
 {
+       acpi_hide_nondev_subnodes(&dev->data);
+
        if (dev->flags.power_manageable) {
                device_remove_file(&dev->dev, &dev_attr_power_state);
                if (dev->power.flags.power_resources)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 17c436de376b7c80f2648be33535dbaf52193c47..333f9146d19e1c02d6f0c1572f59847660963e27 100644 (file)
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -64,12 +64,13 @@ static bool acpi_nondev_subnode_ok(acpi_handle scope,
                goto fail;
 
        if (acpi_extract_properties(buf.pointer, &dn->data))
-               dn->data.pointer = buf.pointer;
+               dn->handle = handle;
 
        if (acpi_enumerate_nondev_subnodes(scope, buf.pointer, &dn->data))
-               dn->data.pointer = buf.pointer;
+               dn->handle = handle;
 
-       if (dn->data.pointer) {
+       if (dn->handle) {
+               dn->data.pointer = buf.pointer;
                list_add_tail(&dn->sibling, list);
                return true;
        }
@@ -302,6 +303,7 @@ static void acpi_destroy_nondev_subnodes(struct list_head *list)
 
        list_for_each_entry_safe_reverse(dn, next, list, sibling) {
                acpi_destroy_nondev_subnodes(&dn->data.subnodes);
+               wait_for_completion(&dn->kobj_done);
                list_del(&dn->sibling);
                ACPI_FREE((void *)dn->data.pointer);
                kfree(dn);

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 79cfee646d6ba73bf8778c37a7fbd2c76cebe0f3..e0d7c193d6e025850cd7224bb5fb701ba9959d3f 100644 (file)
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -382,9 +382,12 @@ struct acpi_device {
 /* Non-device subnode */
 struct acpi_data_node {
        const char *name;
+       acpi_handle handle;
        struct fwnode_handle fwnode;
        struct acpi_device_data data;
        struct list_head sibling;
+       struct kobject kobj;
+       struct completion kobj_done;
 };
 
 static inline bool acpi_check_dma(struct acpi_device *adev, bool *coherent)