rapidio: move rio_pw_enable into core code

Make rio_pw_enable() routine available to other RapidIO drivers.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/rapidio/rio-scan.c

@@ -973,17 +973,6 @@ static void rio_init_em(struct rio_dev *rdev)
 	}
 }
 
-/**
- * rio_pw_enable - Enables/disables port-write handling by a master port
- * @port: Master port associated with port-write handling
- * @enable:  1=enable,  0=disable
- */
-static void rio_pw_enable(struct rio_mport *port, int enable)
-{
-	if (port->ops->pwenable)
-		port->ops->pwenable(port, enable);
-}
-
 /**
  * rio_enum_mport- Start enumeration through a master port
  * @mport: Master port to send transactions

drivers/rapidio/rio.c

@@ -559,6 +559,24 @@ int rio_release_inb_pwrite(struct rio_dev *rdev)
 }
 EXPORT_SYMBOL_GPL(rio_release_inb_pwrite);
 
+/**
+ * rio_pw_enable - Enables/disables port-write handling by a master port
+ * @mport: Master port associated with port-write handling
+ * @enable:  1=enable,  0=disable
+ */
+void rio_pw_enable(struct rio_mport *mport, int enable)
+{
+	if (mport->ops->pwenable) {
+		mutex_lock(&mport->lock);
+
+		if ((enable && ++mport->pwe_refcnt == 1) ||
+		    (!enable && mport->pwe_refcnt && --mport->pwe_refcnt == 0))
+			mport->ops->pwenable(mport, enable);
+		mutex_unlock(&mport->lock);
+	}
+}
+EXPORT_SYMBOL_GPL(rio_pw_enable);
+
 /**
  * rio_map_inb_region -- Map inbound memory region.
  * @mport: Master port.
@@ -2041,6 +2059,7 @@ int rio_mport_initialize(struct rio_mport *mport)
 	mport->host_deviceid = rio_get_hdid(mport->id);
 	mport->nscan = NULL;
 	mutex_init(&mport->lock);
+	mport->pwe_refcnt = 0;
 
 	return 0;
 }

include/linux/rio.h

@@ -266,6 +266,7 @@ enum rio_phy_type {
  * @dma: DMA device associated with mport
  * @nscan: RapidIO network enumeration/discovery operations
  * @state: mport device state
+ * @pwe_refcnt: port-write enable ref counter to track enable/disable requests
  */
 struct rio_mport {
 	struct list_head dbells;	/* list of doorbell events */
@@ -296,6 +297,7 @@ struct rio_mport {
 #endif
 	struct rio_scan *nscan;
 	atomic_t state;
+	unsigned int pwe_refcnt;
 };
 
 static inline int rio_mport_is_running(struct rio_mport *mport)

include/linux/rio_drv.h

@@ -375,6 +375,7 @@ extern int rio_request_inb_pwrite(struct rio_dev *,
 			int (*)(struct rio_dev *, union rio_pw_msg*, int));
 extern int rio_release_inb_pwrite(struct rio_dev *);
 extern int rio_inb_pwrite_handler(union rio_pw_msg *pw_msg);
+extern void rio_pw_enable(struct rio_mport *mport, int enable);
 
 /* LDM support */
 int rio_register_driver(struct rio_driver *);