vmxnet3: coverity woe

[vpp.git] / src / plugins / vmxnet3 / output.c

diff --git a/src/plugins/vmxnet3/output.c b/src/plugins/vmxnet3/output.c
index 2ca1cc9..bcb0294 100644 (file)
--- a/src/plugins/vmxnet3/output.c
+++ b/src/plugins/vmxnet3/output.c
@@ -59,25 +59,22 @@ vmxnet3_txq_release (vlib_main_t * vm, vmxnet3_device_t * vd,
                     vmxnet3_txq_t * txq)
 {
   vmxnet3_tx_comp *tx_comp;
-  u32 bi0;
   vmxnet3_tx_comp_ring *comp_ring;
-  u16 eop_idx, desc_idx;
 
   comp_ring = &txq->tx_comp_ring;
   tx_comp = &txq->tx_comp[comp_ring->next];
 
   while ((tx_comp->flags & VMXNET3_TXCF_GEN) == comp_ring->gen)
     {
-      eop_idx = tx_comp->index & VMXNET3_TXC_INDEX;
-      do
+      u16 eop_idx = tx_comp->index & VMXNET3_TXC_INDEX;
+      u32 bi0 = txq->tx_ring.bufs[txq->tx_ring.consume];
+
+      vlib_buffer_free_one (vm, bi0);
+      while (txq->tx_ring.consume != eop_idx)
        {
-         desc_idx = txq->tx_ring.consume;
-         bi0 = txq->tx_ring.bufs[desc_idx];
-         txq->tx_ring.bufs[desc_idx] = ~0;
-         vlib_buffer_free_no_next (vm, &bi0, 1);
          vmxnet3_tx_ring_advance_consume (txq);
        }
-      while (desc_idx != eop_idx);
+      vmxnet3_tx_ring_advance_consume (txq);
 
       vmxnet3_tx_comp_ring_advance_next (txq);
       tx_comp = &txq->tx_comp[comp_ring->next];
@@ -106,26 +103,56 @@ VNET_DEVICE_CLASS_TX_FN (vmxnet3_device_class) (vlib_main_t * vm,
   u32 *buffers = vlib_frame_args (frame);
   u32 bi0;
   vlib_buffer_t *b0;
-  vmxnet3_tx_desc *txd;
+  vmxnet3_tx_desc *txd = 0;
   u32 desc_idx, generation, first_idx;
   u16 space_left;
   u16 n_left = frame->n_vectors;
   vmxnet3_txq_t *txq;
   u32 thread_index = vm->thread_index;
   u16 qid = thread_index;
-  u16 n_retry = 5;
 
-  txq = vec_elt_at_index (vd->txqs, qid % vd->num_tx_queues);
+  if (PREDICT_FALSE (!(vd->flags & VMXNET3_DEVICE_F_LINK_UP)))
+    {
+      vlib_buffer_free (vm, buffers, n_left);
+      vlib_error_count (vm, node->node_index, VMXNET3_TX_ERROR_LINK_DOWN,
+                       n_left);
+      return (0);
+    }
 
+  txq = vec_elt_at_index (vd->txqs, qid % vd->num_tx_queues);
   clib_spinlock_lock_if_init (&txq->lock);
 
-retry:
   vmxnet3_txq_release (vm, vd, txq);
 
   while (n_left)
     {
+      u16 space_needed = 1, i;
+      vlib_buffer_t *b;
+
       bi0 = buffers[0];
-      txd = 0;
+      b0 = vlib_get_buffer (vm, bi0);
+      b = b0;
+
+      space_left = vmxnet3_tx_ring_space_left (txq);
+      while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
+       {
+         u32 next_buffer = b->next_buffer;
+
+         b = vlib_get_buffer (vm, next_buffer);
+         space_needed++;
+       }
+      if (PREDICT_FALSE (space_left < space_needed))
+       {
+         vlib_buffer_free_one (vm, bi0);
+         vlib_error_count (vm, node->node_index,
+                           VMXNET3_TX_ERROR_NO_FREE_SLOTS, 1);
+         buffers++;
+         n_left--;
+         /*
+          * Drop this packet. But we may have enough room for the next packet
+          */
+         continue;
+       }
 
       /*
        * Toggle the generation bit for SOP fragment to avoid device starts
@@ -133,17 +160,11 @@ retry:
        */
       generation = txq->tx_ring.gen ^ VMXNET3_TXF_GEN;
       first_idx = txq->tx_ring.produce;
-      while (1)
+      for (i = 0; i < space_needed; i++)
        {
          b0 = vlib_get_buffer (vm, bi0);
          VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
 
-         space_left = vmxnet3_tx_ring_space_left (txq);
-         if (PREDICT_FALSE (space_left == 0))
-           {
-             break;
-           }
-
          desc_idx = txq->tx_ring.produce;
 
          vmxnet3_tx_ring_advance_produce (txq);
@@ -157,44 +178,24 @@ retry:
          txd->flags[0] = generation | b0->current_length;
 
          generation = txq->tx_ring.gen;
-         if (b0->flags & VLIB_BUFFER_NEXT_PRESENT)
-           {
-             txd->flags[1] = 0;
-             bi0 = b0->next_buffer;
-           }
-         else
-           break;
-       }
 
-      if (PREDICT_TRUE (txd != 0))
-       {
-         txd->flags[1] = VMXNET3_TXF_CQ | VMXNET3_TXF_EOP;
-         asm volatile ("":::"memory");
-         /*
-          * Now toggle back the generation bit for the first segment.
-          * Device can start reading the packet
-          */
-         txq->tx_desc[first_idx].flags[0] ^= VMXNET3_TXF_GEN;
-         vmxnet3_reg_write (vd, 0, VMXNET3_REG_TXPROD, txq->tx_ring.produce);
+         txd->flags[1] = 0;
+         bi0 = b0->next_buffer;
        }
 
-      if (PREDICT_FALSE (space_left == 0))
-       {
-         break;
-       }
+      txd->flags[1] = VMXNET3_TXF_CQ | VMXNET3_TXF_EOP;
+      asm volatile ("":::"memory");
+      /*
+       * Now toggle back the generation bit for the first segment.
+       * Device can start reading the packet
+       */
+      txq->tx_desc[first_idx].flags[0] ^= VMXNET3_TXF_GEN;
+      vmxnet3_reg_write (vd, 0, VMXNET3_REG_TXPROD, txq->tx_ring.produce);
 
       buffers++;
       n_left--;
     }
 
-  if (PREDICT_FALSE (n_left))
-    {
-      if (PREDICT_TRUE (n_retry--))
-       goto retry;
-      vlib_buffer_free (vm, buffers, n_left);
-      vlib_error_count (vm, node->node_index, VMXNET3_TX_ERROR_NO_FREE_SLOTS,
-                       n_left);
-    }
   clib_spinlock_unlock_if_init (&txq->lock);
 
   return (frame->n_vectors - n_left);