[PATCH 2/3] rapidio: add enumeration/discovery start from user space

@@ -66,4 +66,13 @@ config RAPIDIO_ENUM_BASIC
 
 endchoice
 
+config RAPIDIO_ENUM_AUTO
+	bool "Automatic RapidIO enumeration/discovery start"
+	depends on RAPIDIO && RAPIDIO_ENUM_BASIC = y
+	help
+	  Say Y if you want RapidIO subsystem to start fabric enumeration and
+	  discovery automatically during kernel initialization time.
+	  If you are unsure, say N here. You will be able to start RapidIO
+	  fabric enumeration or discovery later by a user request.
+
 source "drivers/rapidio/switches/Kconfig"

@@ -207,6 +207,7 @@ struct bus_type rio_bus_type = {
 	.name = "rapidio",
 	.match = rio_match_bus,
 	.dev_attrs = rio_dev_attrs,
+	.bus_attrs = rio_bus_attrs,
 	.probe = rio_device_probe,
 	.remove = rio_device_remove,
 };

@@ -1134,19 +1134,30 @@ static void rio_pw_enable(struct rio_mport *port, int enable)
 /**
  * rio_enum_mport- Start enumeration through a master port
  * @mport: Master port to send transactions
+ * @flags: Enumeration control flags
  *
  * Starts the enumeration process. If somebody has enumerated our
  * master port device, then give up. If not and we have an active
  * link, then start recursive peer enumeration. Returns %0 if
  * enumeration succeeds or %-EBUSY if enumeration fails.
  */
-int rio_enum_mport(struct rio_mport *mport)
+int rio_enum_mport(struct rio_mport *mport, u32 flags)
 {
 	struct rio_net *net = NULL;
 	int rc = 0;
 
 	printk(KERN_INFO "RIO: enumerate master port %d, %s\n", mport->id,
 	       mport->name);
+
+	/*
+	 * To avoid multiple start requests (repeat enumeration is not supported
+	 * by this method) check if enumeration/discovery was performed for this
+	 * mport: if mport was added into the list of mports for a net exit
+	 * with error.
+	 */
+	if (mport->nnode.next || mport->nnode.prev)
+		return -EBUSY;
+
 	/* If somebody else enumerated our master port device, bail. */
 	if (rio_enum_host(mport) < 0) {
 		printk(KERN_INFO

@@ -1236,14 +1247,16 @@ static void rio_build_route_tables(struct rio_net *net)
 /**
  * rio_disc_mport- Start discovery through a master port
  * @mport: Master port to send transactions
+ * @flags: discovery control flags
  *
  * Starts the discovery process. If we have an active link,
- * then wait for the signal that enumeration is complete.
+ * then wait for the signal that enumeration is complete (if wait
+ * is allowed).
  * When enumeration completion is signaled, start recursive
  * peer discovery. Returns %0 if discovery succeeds or %-EBUSY
  * on failure.
  */
-int rio_disc_mport(struct rio_mport *mport)
+int rio_disc_mport(struct rio_mport *mport, u32 flags)
 {
 	struct rio_net *net = NULL;
 	unsigned long to_end;

@@ -1253,6 +1266,11 @@ int rio_disc_mport(struct rio_mport *mport)
 
 	/* If master port has an active link, allocate net and discover peers */
 	if (rio_mport_is_active(mport)) {
+		if (rio_enum_complete(mport))
+			goto enum_done;
+		else if (flags & RIO_SCAN_ENUM_NO_WAIT)
+			return -EAGAIN;
+
 		pr_debug("RIO: wait for enumeration to complete...\n");
 
 		to_end = jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;

@@ -285,3 +285,48 @@ void rio_remove_sysfs_dev_files(struct rio_dev *rdev)
 			rdev->rswitch->sw_sysfs(rdev, RIO_SW_SYSFS_REMOVE);
 	}
 }
+
+static ssize_t bus_scan_store(struct bus_type *bus, const char *buf,
+				size_t count)
+{
+	long val;
+	struct rio_mport *port = NULL;
+	int rc;
+
+	if (kstrtol(buf, 0, &val) < 0)
+		return -EINVAL;
+
+	if (val == RIO_MPORT_ANY) {
+		rc = rio_init_mports();
+		goto exit;
+	}
+
+	if (val < 0 || val >= RIO_MAX_MPORTS)
+		return -EINVAL;
+
+	port = rio_find_mport((int)val);
+
+	if (!port) {
+		pr_debug("RIO: %s: mport_%d not available\n",
+			 __func__, (int)val);
+		return -EINVAL;
+	}
+
+	if (!port->nscan)
+		return -EINVAL;
+
+	if (port->host_deviceid >= 0)
+		rc = port->nscan->enumerate(port, 0);
+	else
+		rc = port->nscan->discover(port, RIO_SCAN_ENUM_NO_WAIT);
+exit:
+	if (!rc)
+		rc = count;
+
+	return rc;
+}
+
+struct bus_attribute rio_bus_attrs[] = {
+	__ATTR(scan, (S_IWUSR|S_IWGRP), NULL, bus_scan_store),
+	__ATTR_NULL
+};

@@ -1382,6 +1382,26 @@ EXPORT_SYMBOL_GPL(rio_dma_prep_slave_sg);
 #endif /* CONFIG_RAPIDIO_DMA_ENGINE */
 
 /**
+ * rio_find_mport - find RIO mport by its ID
+ * @mport_id: number (ID) of mport device
+ *
+ * Given a RIO mport number, the desired mport is located
+ * in the global list of mports. If the mport is found, a pointer to its
+ * data structure is returned.  If no mport is found, %NULL is returned.
+ */
+struct rio_mport *rio_find_mport(int mport_id)
+{
+	struct rio_mport *port = NULL;
+
+	list_for_each_entry(port, &rio_mports, node) {
+		if (port->id == mport_id)
+			return port;
+	}
+
+	return NULL;
+}
+
+/**
  * rio_register_scan - enumeration/discovery method registration interface
  * @mport_id: mport device ID for which fabric scan routine has to be set
  *            (RIO_MPORT_ANY = set for all available mports)

@@ -1470,7 +1490,7 @@ static void disc_work_handler(struct work_struct *_work)
 	work = container_of(_work, struct rio_disc_work, work);
 	pr_debug("RIO: discovery work for mport %d %s\n",
 		 work->mport->id, work->mport->name);
-	work->mport->nscan->discover(work->mport);
+	work->mport->nscan->discover(work->mport, 0);
 }
 
 int rio_init_mports(void)

@@ -1489,7 +1509,7 @@ int rio_init_mports(void)
 	list_for_each_entry(port, &rio_mports, node) {
 		if (port->host_deviceid >= 0) {
 			if (port->nscan)
-				port->nscan->enumerate(port);
+				port->nscan->enumerate(port, 0);
 		} else
 			n++;
 	}

@@ -1539,7 +1559,9 @@ no_disc:
 	return 0;
 }
 
+#ifdef CONFIG_RAPIDIO_ENUM_AUTO
 device_initcall_sync(rio_init_mports);
+#endif
 
 static int hdids[RIO_MAX_MPORTS + 1];
 

@@ -45,9 +45,11 @@ extern int rio_enable_rx_tx_port(struct rio_mport *port, int local, u16 destid,
 extern int rio_register_scan(int mport_id, struct rio_scan *scan_ops);
 extern int rio_unregister_scan(int mport_id);
 extern void rio_attach_device(struct rio_dev *rdev);
+extern struct rio_mport *rio_find_mport(int mport_id);
 
 /* Structures internal to the RIO core code */
 extern struct device_attribute rio_dev_attrs[];
+extern struct bus_attribute rio_bus_attrs[];
 extern spinlock_t rio_global_list_lock;
 
 extern struct rio_switch_ops __start_rio_switch_ops[];

@@ -266,6 +266,11 @@ struct rio_mport {
 	struct rio_scan *nscan;
 };
 
+/*
+ * Enumeration/discovery control flags
+ */
+#define RIO_SCAN_ENUM_NO_WAIT	0x00000001 /* Do not wait for enum completed */
+
 struct rio_id_table {
 	u16 start;	/* logical minimal id */
 	u32 max;	/* max number of IDs in table */

@@ -468,8 +473,8 @@ static inline struct rio_mport *dma_to_mport(struct dma_device *ddev)
  * @discover: Callback to perform RapidIO fabric discovery.
  */
 struct rio_scan {
-	int (*enumerate)(struct rio_mport *mport);
-	int (*discover)(struct rio_mport *mport);
+	int (*enumerate)(struct rio_mport *mport, u32 flags);
+	int (*discover)(struct rio_mport *mport, u32 flags);
 };
 
 /* Architecture and hardware-specific functions */