Merge tag 'powerpc-spectre-rsb' of powerpc-CVE-2019-18660.bundle

[linux.git] / include / linux / fwnode.h

diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index ababd6bc82f33cc75e5733c92ca6005f30a9bc16..8feeb94b8acc79e48f6897c21b2822cff56e11fc 100644 (file)
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -17,6 +17,7 @@ struct device;
 struct fwnode_handle {
        struct fwnode_handle *secondary;
        const struct fwnode_operations *ops;
+       struct device *dev;
 };
 
 /**
@@ -49,13 +50,15 @@ struct fwnode_reference_args {
  * struct fwnode_operations - Operations for fwnode interface
  * @get: Get a reference to an fwnode.
  * @put: Put a reference to an fwnode.
+ * @device_is_available: Return true if the device is available.
  * @device_get_match_data: Return the device driver match data.
  * @property_present: Return true if a property is present.
- * @property_read_integer_array: Read an array of integer properties. Return
- *                              zero on success, a negative error code
- *                              otherwise.
+ * @property_read_int_array: Read an array of integer properties. Return zero on
+ *                          success, a negative error code otherwise.
  * @property_read_string_array: Read an array of string properties. Return zero
  *                             on success, a negative error code otherwise.
+ * @get_name: Return the name of an fwnode.
+ * @get_name_prefix: Get a prefix for a node (for printing purposes).
  * @get_parent: Return the parent of an fwnode.
  * @get_next_child_node: Return the next child node in an iteration.
  * @get_named_child_node: Return a child node with a given name.
@@ -65,6 +68,44 @@ struct fwnode_reference_args {
  *                            endpoint node.
  * @graph_get_port_parent: Return the parent node of a port node.
  * @graph_parse_endpoint: Parse endpoint for port and endpoint id.
+ * @add_links: Called after the device corresponding to the fwnode is added
+ *             using device_add(). The function is expected to create device
+ *             links to all the suppliers of the device that are available at
+ *             the time this function is called.  The function must NOT stop
+ *             at the first failed device link if other unlinked supplier
+ *             devices are present in the system.  This is necessary for the
+ *             driver/bus sync_state() callbacks to work correctly.
+ *
+ *             For example, say Device-C depends on suppliers Device-S1 and
+ *             Device-S2 and the dependency is listed in that order in the
+ *             firmware.  Say, S1 gets populated from the firmware after
+ *             late_initcall_sync().  Say S2 is populated and probed way
+ *             before that in device_initcall(). When C is populated, if this
+ *             add_links() function doesn't continue past a "failed linking to
+ *             S1" and continue linking C to S2, then S2 will get a
+ *             sync_state() callback before C is probed. This is because from
+ *             the perspective of S2, C was never a consumer when its
+ *             sync_state() evaluation is done. To avoid this, the add_links()
+ *             function has to go through all available suppliers of the
+ *             device (that corresponds to this fwnode) and link to them
+ *             before returning.
+ *
+ *             If some suppliers are not yet available (indicated by an error
+ *             return value), this function will be called again when other
+ *             devices are added to allow creating device links to any newly
+ *             available suppliers.
+ *
+ *             Return 0 if device links have been successfully created to all
+ *             the known suppliers of this device or if the supplier
+ *             information is not known.
+ *
+ *             Return -ENODEV if the suppliers needed for probing this device
+ *             have not been registered yet (because device links can only be
+ *             created to devices registered with the driver core).
+ *
+ *             Return -EAGAIN if some of the suppliers of this device have not
+ *             been registered yet, but none of those suppliers are necessary
+ *             for probing the device.
  */
 struct fwnode_operations {
        struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
@@ -82,6 +123,8 @@ struct fwnode_operations {
        (*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
                                      const char *propname, const char **val,
                                      size_t nval);
+       const char *(*get_name)(const struct fwnode_handle *fwnode);
+       const char *(*get_name_prefix)(const struct fwnode_handle *fwnode);
        struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
        struct fwnode_handle *
        (*get_next_child_node)(const struct fwnode_handle *fwnode,
@@ -102,6 +145,8 @@ struct fwnode_operations {
        (*graph_get_port_parent)(struct fwnode_handle *fwnode);
        int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
                                    struct fwnode_endpoint *endpoint);
+       int (*add_links)(const struct fwnode_handle *fwnode,
+                        struct device *dev);
 };
 
 #define fwnode_has_op(fwnode, op)                              \
@@ -123,5 +168,6 @@ struct fwnode_operations {
                if (fwnode_has_op(fwnode, op))                          \
                        (fwnode)->ops->op(fwnode, ## __VA_ARGS__);      \
        } while (false)
+#define get_dev_from_fwnode(fwnode)    get_device((fwnode)->dev)
 
 #endif