dpif-netdev: Simplify atomic function pointer stores.

The same pattern for atomic stores and initialization was used for the
DPIF and MFEX function pointers declared in struct dp_netdev_pmd_thread.
Simplify this pattern for all stores to 'miniflow_extract_opt' and
'netdev_input_func'.

Also replace the first store to 'miniflow_extract_opt' which was a
atomic_store_relaxed() with atomic_init().

Signed-off-by: Cian Ferriter <cian.ferriter@intel.com>
Acked-by: Kumar Amber <kumar.amber@intel.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

3 files changed, 11 insertions, 25 deletions

diff --git a/lib/dpif-netdev-extract-study.c b/lib/dpif-netdev-extract-study.c
index 5a9370669..69077c844 100644
--- a/lib/dpif-netdev-extract-study.c
+++ b/lib/dpif-netdev-extract-study.c
@@ -120,19 +120,15 @@ mfex_study_traffic(struct dp_packet_batch *packets,
 
         /* If 50% of the packets hit, enable the function. */
         if (max_hits >= (mfex_study_pkts_count / 2)) {
-            miniflow_extract_func mf_func =
-                        miniflow_funcs[best_func_index].extract_func;
-            atomic_uintptr_t *pmd_func = (void *)&pmd->miniflow_extract_opt;
-            atomic_store_relaxed(pmd_func, (uintptr_t) mf_func);
+            atomic_store_relaxed(&pmd->miniflow_extract_opt,
+                                 miniflow_funcs[best_func_index].extract_func);
             VLOG_INFO("MFEX study chose impl %s: (hits %u/%u pkts)",
                       miniflow_funcs[best_func_index].name, max_hits,
                       stats->pkt_count);
         } else {
             /* Set the implementation to null for default miniflow. */
-            miniflow_extract_func mf_func =
-                        miniflow_funcs[MFEX_IMPL_SCALAR].extract_func;
-            atomic_uintptr_t *pmd_func = (void *)&pmd->miniflow_extract_opt;
-            atomic_store_relaxed(pmd_func, (uintptr_t) mf_func);
+            atomic_store_relaxed(&pmd->miniflow_extract_opt,
+                    miniflow_funcs[MFEX_IMPL_SCALAR].extract_func);
             VLOG_INFO("Not enough packets matched (%u/%u), disabling"
                       " optimized MFEX.", max_hits, stats->pkt_count);
         }
diff --git a/lib/dpif-netdev-private-extract.c b/lib/dpif-netdev-private-extract.c
index a29bdcfa7..4b2f12015 100644
--- a/lib/dpif-netdev-private-extract.c
+++ b/lib/dpif-netdev-private-extract.c
@@ -241,9 +241,7 @@ dpif_miniflow_extract_autovalidator(struct dp_packet_batch *packets,
     struct netdev_flow_key test_keys[NETDEV_MAX_BURST];
 
     if (keys_size < cnt) {
-        miniflow_extract_func default_func = NULL;
-        atomic_uintptr_t *pmd_func = (void *)&pmd->miniflow_extract_opt;
-        atomic_store_relaxed(pmd_func, (uintptr_t) default_func);
+        atomic_store_relaxed(&pmd->miniflow_extract_opt, NULL);
         VLOG_ERR("Invalid key size supplied, Key_size: %d less than"
                  "batch_size:  %" PRIuSIZE"\n", keys_size, cnt);
         VLOG_ERR("Autovalidatior is disabled.\n");
@@ -350,9 +348,7 @@ dpif_miniflow_extract_autovalidator(struct dp_packet_batch *packets,
 
     /* Having dumped the debug info for the batch, disable autovalidator. */
     if (batch_failed) {
-        miniflow_extract_func default_func = NULL;
-        atomic_uintptr_t *pmd_func = (void *)&pmd->miniflow_extract_opt;
-        atomic_store_relaxed(pmd_func, (uintptr_t) default_func);
+        atomic_store_relaxed(&pmd->miniflow_extract_opt, NULL);
     }
 
     /* Preserve packet correctness by storing back the good offsets in
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 9f35713ef..720818e30 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -1167,9 +1167,8 @@ dpif_netdev_impl_set(struct unixctl_conn *conn, int argc OVS_UNUSED,
 
             /* Initialize DPIF function pointer to the newly configured
              * default. */
-            dp_netdev_input_func default_func = dp_netdev_impl_get_default();
-            atomic_uintptr_t *pmd_func = (void *) &pmd->netdev_input_func;
-            atomic_store_relaxed(pmd_func, (uintptr_t) default_func);
+            atomic_store_relaxed(&pmd->netdev_input_func,
+                                 dp_netdev_impl_get_default());
         };
 
         free(pmd_list);
@@ -1358,8 +1357,7 @@ dpif_miniflow_extract_impl_set(struct unixctl_conn *conn, int argc,
             }
 
             pmd_thread_update_done = true;
-            atomic_uintptr_t *pmd_func = (void *) &pmd->miniflow_extract_opt;
-            atomic_store_relaxed(pmd_func, (uintptr_t) mfex_func);
+            atomic_store_relaxed(&pmd->miniflow_extract_opt, mfex_func);
         };
 
         free(pmd_list);
@@ -7459,14 +7457,10 @@ dp_netdev_configure_pmd(struct dp_netdev_pmd_thread *pmd, struct dp_netdev *dp,
     cmap_init(&pmd->tx_bonds);
 
     /* Initialize DPIF function pointer to the default configured version. */
-    dp_netdev_input_func default_func = dp_netdev_impl_get_default();
-    atomic_uintptr_t *pmd_func = (void *) &pmd->netdev_input_func;
-    atomic_init(pmd_func, (uintptr_t) default_func);
+    atomic_init(&pmd->netdev_input_func, dp_netdev_impl_get_default());
 
     /* Init default miniflow_extract function */
-    miniflow_extract_func mfex_func = dp_mfex_impl_get_default();
-    atomic_uintptr_t *pmd_func_mfex = (void *)&pmd->miniflow_extract_opt;
-    atomic_store_relaxed(pmd_func_mfex, (uintptr_t) mfex_func);
+    atomic_init(&pmd->miniflow_extract_opt, dp_mfex_impl_get_default());
 
     /* init the 'flow_cache' since there is no
      * actual thread created for NON_PMD_CORE_ID. */