i40evf: support reporting PF reset

[dpdk.git] / lib / librte_ring / rte_ring.h

diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index de036ce..eb45e41 100644 (file)
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -431,6 +431,11 @@ __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
        uint32_t mask = r->prod.mask;
        int ret;
 
+       /* Avoid the unnecessary cmpset operation below, which is also
+        * potentially harmful when n equals 0. */
+       if (n == 0)
+               return 0;
+
        /* move prod.head atomically */
        do {
                /* Reset n to the initial burst count */
@@ -618,6 +623,11 @@ __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
        unsigned i, rep = 0;
        uint32_t mask = r->prod.mask;
 
+       /* Avoid the unnecessary cmpset operation below, which is also
+        * potentially harmful when n equals 0. */
+       if (n == 0)
+               return 0;
+
        /* move cons.head atomically */
        do {
                /* Restore n as it may change every loop */
@@ -1037,7 +1047,7 @@ rte_ring_full(const struct rte_ring *r)
 {
        uint32_t prod_tail = r->prod.tail;
        uint32_t cons_tail = r->cons.tail;
-       return (((cons_tail - prod_tail - 1) & r->prod.mask) == 0);
+       return ((cons_tail - prod_tail - 1) & r->prod.mask) == 0;
 }
 
 /**
@@ -1070,7 +1080,7 @@ rte_ring_count(const struct rte_ring *r)
 {
        uint32_t prod_tail = r->prod.tail;
        uint32_t cons_tail = r->cons.tail;
-       return ((prod_tail - cons_tail) & r->prod.mask);
+       return (prod_tail - cons_tail) & r->prod.mask;
 }
 
 /**
@@ -1086,7 +1096,7 @@ rte_ring_free_count(const struct rte_ring *r)
 {
        uint32_t prod_tail = r->prod.tail;
        uint32_t cons_tail = r->cons.tail;
-       return ((cons_tail - prod_tail - 1) & r->prod.mask);
+       return (cons_tail - prod_tail - 1) & r->prod.mask;
 }
 
 /**