rapidio: add relation links between RIO device structures

Create back and forward links between RIO devices.  These links are
intended for use by error management and hot-plug extensions.  Links for
redundant RIO connections between switches are not set (will be fixed in a
separate patch).

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/rio.h b/include/linux/rio.h
index ffdfe5a..8d9e66d 100644
--- a/include/linux/rio.h
+++ b/include/linux/rio.h
@@ -99,6 +99,7 @@
  * @riores: RIO resources this device owns
  * @pwcback: port-write callback function for this device
  * @destid: Network destination ID
+ * @prev: Previous RIO device connected to the current one
  */
 struct rio_dev {
 	struct list_head global_list;	/* node in list of all RIO devices */
@@ -125,6 +126,7 @@
 	struct resource riores[RIO_MAX_DEV_RESOURCES];
 	int (*pwcback) (struct rio_dev *rdev, union rio_pw_msg *msg, int step);
 	u16 destid;
+	struct rio_dev *prev;
 };
 
 #define rio_dev_g(n) list_entry(n, struct rio_dev, global_list)
@@ -232,6 +234,7 @@
  * @get_domain: Callback for switch-specific domain get function
  * @em_init: Callback for switch-specific error management initialization function
  * @em_handle: Callback for switch-specific error management handler function
+ * @nextdev: Array of per-port pointers to the next attached device
  */
 struct rio_switch {
 	struct list_head node;
@@ -253,6 +256,7 @@
 			   u8 *sw_domain);
 	int (*em_init) (struct rio_dev *dev);
 	int (*em_handle) (struct rio_dev *dev, u8 swport);
+	struct rio_dev *nextdev[0];
 };
 
 /* Low-level architecture-dependent routines */