rapidio: add enumeration/discovery start from user space

Add RapidIO enumeration/discovery start from user space.  User space
start allows to defer RapidIO fabric scan until the moment when all
participating endpoints are initialized avoiding mandatory synchronized
start of all endpoints (which may be challenging in systems with large
number of RapidIO endpoints).

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 26 insertions, 2 deletions

diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index 6e75dda34799..cb1c08996fbb 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -1383,6 +1383,30 @@ 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;
+
+        mutex_lock(&rio_mport_list_lock);
+        list_for_each_entry(port, &rio_mports, node) {
+                if (port->id == mport_id)
+                        goto found;
+        }
+        port = NULL;
+found:
+        mutex_unlock(&rio_mport_list_lock);
+
+        return port;
+}
+
+/**
  * 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)
@@ -1475,7 +1499,7 @@ 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)
@@ -1495,7 +1519,7 @@ 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++;
         }