misc: mic: SCIF connections APIs i.e. accept and connect

SCIF connection APIs which establish a SCIF connection between
a pair of SCIF endpoints. A SCIF connection consists of a
dedicated queue-pair between the endpoints. Client messages are
sent over the queue-pair whereas the signaling associated with the
message is multiplexed over the node queue-pair. Similarly other
control messages such as exposing registered memory are also sent
over the node queue-pair. The SCIF endpoints must be in connected
state to exchange messages, register memory, map remote memory and
trigger DMA transfers. SCIF connections can be set up
asynchronously or synchronously.

Thanks to Johnnie S Peters for authoring parts of this patch during
early bring up of the SCIF driver.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/misc/mic/scif/scif_nm.c b/drivers/misc/mic/scif/scif_nm.c
index 5fefaccaf0d4..0469aad470e7 100644
--- a/drivers/misc/mic/scif/scif_nm.c
+++ b/drivers/misc/mic/scif/scif_nm.c
@@ -20,6 +20,41 @@
 #include "scif_main.h"
 #include "scif_map.h"
 
+/**
+ * scif_invalidate_ep() - Set state for all connected endpoints
+ * to disconnected and wake up all send/recv waitqueues
+ */
+static void scif_invalidate_ep(int node)
+{
+	struct scif_endpt *ep;
+	struct list_head *pos, *tmpq;
+
+	flush_work(&scif_info.conn_work);
+	mutex_lock(&scif_info.connlock);
+	list_for_each_safe(pos, tmpq, &scif_info.disconnected) {
+		ep = list_entry(pos, struct scif_endpt, list);
+		if (ep->remote_dev->node == node) {
+			spin_lock(&ep->lock);
+			scif_cleanup_ep_qp(ep);
+			spin_unlock(&ep->lock);
+		}
+	}
+	list_for_each_safe(pos, tmpq, &scif_info.connected) {
+		ep = list_entry(pos, struct scif_endpt, list);
+		if (ep->remote_dev->node == node) {
+			list_del(pos);
+			spin_lock(&ep->lock);
+			ep->state = SCIFEP_DISCONNECTED;
+			list_add_tail(&ep->list, &scif_info.disconnected);
+			scif_cleanup_ep_qp(ep);
+			wake_up_interruptible(&ep->sendwq);
+			wake_up_interruptible(&ep->recvwq);
+			spin_unlock(&ep->lock);
+		}
+	}
+	mutex_unlock(&scif_info.connlock);
+}
+
 void scif_free_qp(struct scif_dev *scifdev)
 {
 	struct scif_qp *qp = scifdev->qpairs;
@@ -91,6 +126,7 @@ void scif_cleanup_scifdev(struct scif_dev *dev)
 		scif_destroy_intr_wq(dev);
 	}
 	scif_destroy_p2p(dev);
+	scif_invalidate_ep(dev->node);
 	scif_send_acks(dev);
 	if (!dev->node && scif_info.card_initiated_exit) {
 		/*