net: ipa: move more code out of gsi_channel_update()

Move the processing done for TX channels in gsi_channel_update()
into gsi_evt_ring_rx_update().  The called function is called for
both RX and TX channels, so rename it to be gsi_evt_ring_update().
As a result, this code no longer assumes events in an event ring are
associated with just one channel.

Because all events in a ring are handled in that function, we can
move the call to gsi_trans_move_complete() there, and can ring the
event ring doorbell there as well after all new events in the ring
have been processed.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index d08f3e7..4e46974 100644 (file)
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -1344,7 +1344,7 @@ gsi_event_trans(struct gsi *gsi, struct gsi_event *event)
 }
 
 /**
- * gsi_evt_ring_rx_update() - Record lengths of received data
+ * gsi_evt_ring_update() - Update transaction state from hardware
  * @gsi:               GSI pointer
  * @evt_ring_id:       Event ring ID
  * @index:             Event index in ring reported by hardware
@@ -1353,6 +1353,10 @@ gsi_event_trans(struct gsi *gsi, struct gsi_event *event)
  * the buffer.  Every event has a transaction associated with it, and here
  * we update transactions to record their actual received lengths.
  *
+ * When an event for a TX channel arrives we use information in the
+ * transaction to report the number of requests and bytes have been
+ * transferred.
+ *
  * This function is called whenever we learn that the GSI hardware has filled
  * new events since the last time we checked.  The ring's index field tells
  * the first entry in need of processing.  The index provided is the
@@ -1363,7 +1367,7 @@ gsi_event_trans(struct gsi *gsi, struct gsi_event *event)
  *
  * Note that @index always refers to an element *within* the event ring.
  */
-static void gsi_evt_ring_rx_update(struct gsi *gsi, u32 evt_ring_id, u32 index)
+static void gsi_evt_ring_update(struct gsi *gsi, u32 evt_ring_id, u32 index)
 {
        struct gsi_evt_ring *evt_ring = &gsi->evt_ring[evt_ring_id];
        struct gsi_ring *ring = &evt_ring->ring;
@@ -1372,10 +1376,12 @@ static void gsi_evt_ring_rx_update(struct gsi *gsi, u32 evt_ring_id, u32 index)
        u32 event_avail;
        u32 old_index;
 
-       /* We'll start with the oldest un-processed event.  RX channels
-        * replenish receive buffers in single-TRE transactions, so we
-        * can just map that event to its transaction.  Transactions
-        * associated with completion events are consecutive.
+       /* Starting with the oldest un-processed event, determine which
+        * transaction (and which channel) is associated with the event.
+        * For RX channels, update each completed transaction with the
+        * number of bytes that were actually received.  For TX channels
+        * associated with a network device, report to the network stack
+        * the number of transfers and bytes this completion represents.
         */
        old_index = ring->index;
        event = gsi_ring_virt(ring, old_index);
@@ -1394,6 +1400,10 @@ static void gsi_evt_ring_rx_update(struct gsi *gsi, u32 evt_ring_id, u32 index)
 
                if (trans->direction == DMA_FROM_DEVICE)
                        trans->len = __le16_to_cpu(event->len);
+               else
+                       gsi_trans_tx_completed(trans);
+
+               gsi_trans_move_complete(trans);
 
                /* Move on to the next event and transaction */
                if (--event_avail)
@@ -1401,6 +1411,9 @@ static void gsi_evt_ring_rx_update(struct gsi *gsi, u32 evt_ring_id, u32 index)
                else
                        event = gsi_ring_virt(ring, 0);
        } while (event != event_done);
+
+       /* Tell the hardware we've handled these events */
+       gsi_evt_ring_doorbell(gsi, evt_ring_id, index);
 }
 
 /* Initialize a ring, including allocating DMA memory for its entries */
@@ -1499,14 +1512,7 @@ static struct gsi_trans *gsi_channel_update(struct gsi_channel *channel)
         * the number of transactions and bytes this completion represents
         * up the network stack.
         */
-       if (channel->toward_ipa)
-               gsi_trans_tx_completed(trans);
-       gsi_evt_ring_rx_update(gsi, evt_ring_id, index);
-
-       gsi_trans_move_complete(trans);
-
-       /* Tell the hardware we've handled these events */
-       gsi_evt_ring_doorbell(gsi, evt_ring_id, index);
+       gsi_evt_ring_update(gsi, evt_ring_id, index);
 
        return gsi_channel_trans_complete(channel);
 }