libmemif: set data offset for memif buffer

Update descriptor offset based on data pointer
in memif_buffer_t.
Slave only, master will not modify the descriptor.

Type: feature

Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: Ice1e94cec366face650c58df81795f4dea727010

diff --git a/extras/libmemif/src/main.c b/extras/libmemif/src/main.c
index 0c52169..d7345d6 100644 (file)
--- a/extras/libmemif/src/main.c
+++ b/extras/libmemif/src/main.c
@@ -2492,7 +2492,10 @@ memif_tx_burst (memif_conn_handle_t conn, uint16_t qid,
   memif_queue_t *mq = &c->tx_queues[qid];
   memif_ring_t *ring = mq->ring;
   uint16_t mask = (1 << mq->log2_ring_size) - 1;
+  uint32_t offset_mask = c->run_args.buffer_size - 1;
   memif_buffer_t *b0;
+  memif_desc_t *d;
+  int64_t data_offset;
   *tx = 0;
   int err = MEMIF_ERR_SUCCESS;
 
@@ -2515,7 +2518,27 @@ memif_tx_burst (memif_conn_handle_t conn, uint16_t qid,
          err = MEMIF_ERR_INVAL_ARG;
          goto done;
        }
-      ring->desc[b0->desc_index & mask].length = b0->len;
+      d = &ring->desc[b0->desc_index & mask];
+      d->length = b0->len;
+      if (!c->args.is_master)
+       {
+         // reset headroom
+         d->offset = d->offset - (d->offset & offset_mask);
+         // calculate offset from user data
+         data_offset = b0->data - (d->offset + c->regions[d->region].addr);
+         if (data_offset != 0)
+           {
+             /* verify data offset */
+             if ((data_offset < 0) ||
+                 (data_offset > (d->offset + offset_mask)))
+               {
+                 printf ("%ld\n", data_offset);
+                 err = MEMIF_ERR_INVAL_ARG;
+                 goto done;
+               }
+             d->offset += data_offset;
+           }
+       }
 
 #ifdef MEMIF_DBG_SHM
       printf ("offset: %-6d\n", ring->desc[b0->desc_index & mask].offset);
@@ -2608,7 +2631,7 @@ memif_rx_burst (memif_conn_handle_t conn, uint16_t qid,
          b0->flags |= MEMIF_BUFFER_FLAG_NEXT;
          ring->desc[cur_slot & mask].flags &= ~MEMIF_DESC_FLAG_NEXT;
        }
-/*      b0->offset = ring->desc[cur_slot & mask].offset;*/
+
       b0->queue = mq;
 #ifdef MEMIF_DBG_SHM
       printf ("data: %p\n", b0->data);