sunvnet: straighten up message event handling logic

The use of gotos for handling the incoming events made this code
harder to read and support than it should be.  This patch straightens
out and clears up the logic.

Orabug: 23293104

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit bf091f3f362b3c562a18bbf7a2d3e2f3a36eba1d)
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/drivers/net/ethernet/sun/sunvnet_common.c b/drivers/net/ethernet/sun/sunvnet_common.c
index 3c70fca99ff38a680c243d24d56b4cd408b51a0d..d743be447f240b6792f4655c02cc3c79500e56a0 100644 (file)
--- a/drivers/net/ethernet/sun/sunvnet_common.c
+++ b/drivers/net/ethernet/sun/sunvnet_common.c
@@ -738,41 +738,37 @@ static int vnet_event_napi(struct vnet_port *port, int budget)
        struct vio_driver_state *vio = &port->vio;
        int tx_wakeup, err;
        int npkts = 0;
-       int event = (port->rx_event & LDC_EVENT_RESET);
 
-ldc_ctrl:
-       if (unlikely(event == LDC_EVENT_RESET ||
-                    event == LDC_EVENT_UP)) {
-               vio_link_state_change(vio, event);
+       /* we don't expect any other bits */
+       BUG_ON(port->rx_event & ~(LDC_EVENT_DATA_READY |
+                                 LDC_EVENT_RESET |
+                                 LDC_EVENT_UP));
+
+       /* RESET takes precedent over any other event */
+       if (port->rx_event & LDC_EVENT_RESET) {
+               vio_link_state_change(vio, LDC_EVENT_RESET);
+               vnet_port_reset(port);
+               vio_port_up(vio);
+
+               /* If the device is running but its tx queue was
+                * stopped (due to flow control), restart it.
+                * This is necessary since vnet_port_reset()
+                * clears the tx drings and thus we may never get
+                * back a VIO_TYPE_DATA ACK packet - which is
+                * the normal mechanism to restart the tx queue.
+                */
+               if (netif_running(dev))
+                       maybe_tx_wakeup(port);
 
-               if (event == LDC_EVENT_RESET) {
-                       vnet_port_reset(port);
-                       vio_port_up(vio);
-
-                       /* If the device is running but its tx queue was
-                        * stopped (due to flow control), restart it.
-                        * This is necessary since vnet_port_reset()
-                        * clears the tx drings and thus we may never get
-                        * back a VIO_TYPE_DATA ACK packet - which is
-                        * the normal mechanism to restart the tx queue.
-                        */
-                       if (netif_running(dev))
-                               maybe_tx_wakeup(port);
-               }
                port->rx_event = 0;
                return 0;
        }
-       /* We may have multiple LDC events in rx_event. Unroll send_events() */
-       event = (port->rx_event & LDC_EVENT_UP);
-       port->rx_event &= ~(LDC_EVENT_RESET | LDC_EVENT_UP);
-       if (event == LDC_EVENT_UP)
-               goto ldc_ctrl;
-       event = port->rx_event;
-       if (!(event & LDC_EVENT_DATA_READY))
-               return 0;
 
-       /* we dont expect any other bits than RESET, UP, DATA_READY */
-       BUG_ON(event != LDC_EVENT_DATA_READY);
+       if (port->rx_event & LDC_EVENT_UP) {
+               vio_link_state_change(vio, LDC_EVENT_UP);
+               port->rx_event = 0;
+               return 0;
+       }
 
        err = 0;
        tx_wakeup = 0;
@@ -795,25 +791,25 @@ ldc_ctrl:
                        pkt->start_idx = vio_dring_next(dr,
                                                        port->napi_stop_idx);
                        pkt->end_idx = -1;
-                       goto napi_resume;
-               }
-               err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
-               if (unlikely(err < 0)) {
-                       if (err == -ECONNRESET)
-                               vio_conn_reset(vio);
-                       break;
+               } else {
+                       err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
+                       if (unlikely(err < 0)) {
+                               if (err == -ECONNRESET)
+                                       vio_conn_reset(vio);
+                               break;
+                       }
+                       if (err == 0)
+                               break;
+                       viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
+                              msgbuf.tag.type,
+                              msgbuf.tag.stype,
+                              msgbuf.tag.stype_env,
+                              msgbuf.tag.sid);
+                       err = vio_validate_sid(vio, &msgbuf.tag);
+                       if (err < 0)
+                               break;
                }
-               if (err == 0)
-                       break;
-               viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
-                      msgbuf.tag.type,
-                      msgbuf.tag.stype,
-                      msgbuf.tag.stype_env,
-                      msgbuf.tag.sid);
-               err = vio_validate_sid(vio, &msgbuf.tag);
-               if (err < 0)
-                       break;
-napi_resume:
+
                if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
                        if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
                                if (!sunvnet_port_is_up_common(port)) {