lpm: avoid race conditions for v20

[dpdk.git] / lib / librte_lpm / rte_lpm.c

diff --git a/lib/librte_lpm/rte_lpm.c b/lib/librte_lpm/rte_lpm.c
index b49e544..5bd8ab9 100644 (file)
--- a/lib/librte_lpm/rte_lpm.c
+++ b/lib/librte_lpm/rte_lpm.c
@@ -738,7 +738,8 @@ add_depth_small_v20(struct rte_lpm_v20 *lpm, uint32_t ip, uint8_t depth,
                        /* Setting tbl24 entry in one go to avoid race
                         * conditions
                         */
-                       lpm->tbl24[i] = new_tbl24_entry;
+                       __atomic_store(&lpm->tbl24[i], &new_tbl24_entry,
+                                       __ATOMIC_RELEASE);
 
                        continue;
                }
@@ -893,7 +894,8 @@ add_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked, uint8_t depth,
                        .depth = 0,
                };
 
-               lpm->tbl24[tbl24_index] = new_tbl24_entry;
+               __atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
+                               __ATOMIC_RELEASE);
 
        } /* If valid entry but not extended calculate the index into Table8. */
        else if (lpm->tbl24[tbl24_index].valid_group == 0) {
@@ -939,7 +941,8 @@ add_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked, uint8_t depth,
                                .depth = 0,
                };
 
-               lpm->tbl24[tbl24_index] = new_tbl24_entry;
+               __atomic_store(&lpm->tbl24[tbl24_index], &new_tbl24_entry,
+                               __ATOMIC_RELEASE);
 
        } else { /*
                * If it is valid, extended entry calculate the index into tbl8.
@@ -1321,7 +1324,15 @@ delete_depth_small_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked,
 
                        if (lpm->tbl24[i].valid_group == 0 &&
                                        lpm->tbl24[i].depth <= depth) {
-                               lpm->tbl24[i].valid = INVALID;
+                               struct rte_lpm_tbl_entry_v20
+                                       zero_tbl24_entry = {
+                                               .valid = INVALID,
+                                               .depth = 0,
+                                               .valid_group = 0,
+                                       };
+                                       zero_tbl24_entry.next_hop = 0;
+                               __atomic_store(&lpm->tbl24[i],
+                                       &zero_tbl24_entry, __ATOMIC_RELEASE);
                        } else if (lpm->tbl24[i].valid_group == 1) {
                                /*
                                 * If TBL24 entry is extended, then there has
@@ -1366,7 +1377,8 @@ delete_depth_small_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked,
 
                        if (lpm->tbl24[i].valid_group == 0 &&
                                        lpm->tbl24[i].depth <= depth) {
-                               lpm->tbl24[i] = new_tbl24_entry;
+                               __atomic_store(&lpm->tbl24[i], &new_tbl24_entry,
+                                               __ATOMIC_RELEASE);
                        } else  if (lpm->tbl24[i].valid_group == 1) {
                                /*
                                 * If TBL24 entry is extended, then there has
@@ -1648,8 +1660,11 @@ delete_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked,
        tbl8_recycle_index = tbl8_recycle_check_v20(lpm->tbl8, tbl8_group_start);
 
        if (tbl8_recycle_index == -EINVAL) {
-               /* Set tbl24 before freeing tbl8 to avoid race condition. */
+               /* Set tbl24 before freeing tbl8 to avoid race condition.
+                * Prevent the free of the tbl8 group from hoisting.
+                */
                lpm->tbl24[tbl24_index].valid = 0;
+               __atomic_thread_fence(__ATOMIC_RELEASE);
                tbl8_free_v20(lpm->tbl8, tbl8_group_start);
        } else if (tbl8_recycle_index > -1) {
                /* Update tbl24 entry. */
@@ -1660,8 +1675,11 @@ delete_depth_big_v20(struct rte_lpm_v20 *lpm, uint32_t ip_masked,
                        .depth = lpm->tbl8[tbl8_recycle_index].depth,
                };
 
-               /* Set tbl24 before freeing tbl8 to avoid race condition. */
+               /* Set tbl24 before freeing tbl8 to avoid race condition.
+                * Prevent the free of the tbl8 group from hoisting.
+                */
                lpm->tbl24[tbl24_index] = new_tbl24_entry;
+               __atomic_thread_fence(__ATOMIC_RELEASE);
                tbl8_free_v20(lpm->tbl8, tbl8_group_start);
        }