thunderbolt: Introduce thunderbolt bus and connection manager

Thunderbolt fabric consists of one or more switches. This fabric is
called domain and it is controlled by an entity called connection
manager. The connection manager can be either internal (driven by a
firmware running on the host controller) or external (software driver).
This driver currently implements support for the latter.

In order to manage switches and their properties more easily we model
this domain structure as a Linux bus. Each host controller adds a domain
device to this bus, and these devices are named as domainN where N
stands for index or id of the current domain.

We then abstract connection manager specific operations into a new
structure tb_cm_ops and convert the existing tb.c to fill those
accordingly. This makes it easier to add support for the internal
connection manager in subsequent patches.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 53 insertions, 17 deletions

diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 0b78bc4fbe61..5fab4c44f124 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -92,29 +92,52 @@ struct tb_path {
 	int path_length; /* number of hops */
 };
 
+/**
+ * struct tb_cm_ops - Connection manager specific operations vector
+ * @start: Starts the domain
+ * @stop: Stops the domain
+ * @suspend_noirq: Connection manager specific suspend_noirq
+ * @resume_noirq: Connection manager specific resume_noirq
+ * @hotplug: Handle hotplug event
+ */
+struct tb_cm_ops {
+	int (*start)(struct tb *tb);
+	void (*stop)(struct tb *tb);
+	int (*suspend_noirq)(struct tb *tb);
+	int (*resume_noirq)(struct tb *tb);
+	hotplug_cb hotplug;
+};
 
 /**
  * struct tb - main thunderbolt bus structure
+ * @dev: Domain device
+ * @lock: Big lock. Must be held when accessing cfg or any struct
+ *	  tb_switch / struct tb_port.
+ * @nhi: Pointer to the NHI structure
+ * @ctl: Control channel for this domain
+ * @wq: Ordered workqueue for all domain specific work
+ * @root_switch: Root switch of this domain
+ * @cm_ops: Connection manager specific operations vector
+ * @index: Linux assigned domain number
+ * @privdata: Private connection manager specific data
  */
 struct tb {
-	struct mutex lock;	/*
-				 * Big lock. Must be held when accessing cfg or
-				 * any struct tb_switch / struct tb_port.
-				 */
+	struct device dev;
+	struct mutex lock;
 	struct tb_nhi *nhi;
 	struct tb_ctl *ctl;
-	struct workqueue_struct *wq; /* ordered workqueue for plug events */
+	struct workqueue_struct *wq;
 	struct tb_switch *root_switch;
-	struct list_head tunnel_list; /* list of active PCIe tunnels */
-	bool hotplug_active; /*
-			      * tb_handle_hotplug will stop progressing plug
-			      * events and exit if this is not set (it needs to
-			      * acquire the lock one more time). Used to drain
-			      * wq after cfg has been paused.
-			      */
-
+	const struct tb_cm_ops *cm_ops;
+	int index;
+	unsigned long privdata[0];
 };
 
+static inline void *tb_priv(struct tb *tb)
+{
+	return (void *)tb->privdata;
+}
+
 /* helper functions & macros */
 
 /**
@@ -215,11 +238,24 @@ static inline int tb_port_write(struct tb_port *port, const void *buffer,
 #define tb_port_info(port, fmt, arg...) \
 	__TB_PORT_PRINT(tb_info, port, fmt, ##arg)
 
+struct tb *tb_probe(struct tb_nhi *nhi);
+
+extern struct bus_type tb_bus_type;
+extern struct device_type tb_domain_type;
+
+int tb_domain_init(void);
+void tb_domain_exit(void);
 
-struct tb *thunderbolt_alloc_and_start(struct tb_nhi *nhi);
-void thunderbolt_shutdown_and_free(struct tb *tb);
-void thunderbolt_suspend(struct tb *tb);
-void thunderbolt_resume(struct tb *tb);
+struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize);
+int tb_domain_add(struct tb *tb);
+void tb_domain_remove(struct tb *tb);
+int tb_domain_suspend_noirq(struct tb *tb);
+int tb_domain_resume_noirq(struct tb *tb);
+
+static inline void tb_domain_put(struct tb *tb)
+{
+	put_device(&tb->dev);
+}
 
 struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route);
 void tb_switch_free(struct tb_switch *sw);