ring: create common structure for prod and cons metadata

[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 f928324..331c94f 100644 (file)
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -1,7 +1,7 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
  *   All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
@@ -106,7 +106,7 @@ extern "C" {
 
 enum rte_ring_queue_behavior {
        RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */
-       RTE_RING_QUEUE_VARIABLE   /* Enq/Deq as many items a possible from ring */
+       RTE_RING_QUEUE_VARIABLE   /* Enq/Deq as many items as possible from ring */
 };
 
 #ifdef RTE_LIBRTE_RING_DEBUG
@@ -139,6 +139,24 @@ struct rte_ring_debug_stats {
 
 struct rte_memzone; /* forward declaration, so as not to require memzone.h */
 
+#if RTE_CACHE_LINE_SIZE < 128
+#define PROD_ALIGN (RTE_CACHE_LINE_SIZE * 2)
+#define CONS_ALIGN (RTE_CACHE_LINE_SIZE * 2)
+#else
+#define PROD_ALIGN RTE_CACHE_LINE_SIZE
+#define CONS_ALIGN RTE_CACHE_LINE_SIZE
+#endif
+
+/* structure to hold a pair of head/tail values and other metadata */
+struct rte_ring_headtail {
+       volatile uint32_t head;  /**< Prod/consumer head. */
+       volatile uint32_t tail;  /**< Prod/consumer tail. */
+       uint32_t size;           /**< Size of ring. */
+       uint32_t mask;           /**< Mask (size-1) of ring. */
+       uint32_t single;         /**< True if single prod/cons */
+       uint32_t watermark;      /**< Max items before EDQUOT in producer. */
+};
+
 /**
  * An RTE ring structure.
  *
@@ -161,33 +179,16 @@ struct rte_ring {
                        /**< Memzone, if any, containing the rte_ring */
 
        /** Ring producer status. */
-       struct prod {
-               uint32_t watermark;      /**< Maximum items before EDQUOT. */
-               uint32_t sp_enqueue;     /**< True, if single producer. */
-               uint32_t size;           /**< Size of ring. */
-               uint32_t mask;           /**< Mask (size-1) of ring. */
-               volatile uint32_t head;  /**< Producer head. */
-               volatile uint32_t tail;  /**< Producer tail. */
-       } prod __rte_cache_aligned;
+       struct rte_ring_headtail prod __rte_aligned(PROD_ALIGN);
 
        /** Ring consumer status. */
-       struct cons {
-               uint32_t sc_dequeue;     /**< True, if single consumer. */
-               uint32_t size;           /**< Size of the ring. */
-               uint32_t mask;           /**< Mask (size-1) of ring. */
-               volatile uint32_t head;  /**< Consumer head. */
-               volatile uint32_t tail;  /**< Consumer tail. */
-#ifdef RTE_RING_SPLIT_PROD_CONS
-       } cons __rte_cache_aligned;
-#else
-       } cons;
-#endif
+       struct rte_ring_headtail cons __rte_aligned(CONS_ALIGN);
 
 #ifdef RTE_LIBRTE_RING_DEBUG
        struct rte_ring_debug_stats stats[RTE_MAX_LCORE];
 #endif
 
-       void * ring[0] __rte_cache_aligned; /**< Memory space of ring starts here.
+       void *ring[] __rte_cache_aligned;   /**< Memory space of ring starts here.
                                             * not volatile so need to be careful
                                             * about compiler re-ordering */
 };
@@ -341,7 +342,7 @@ void rte_ring_free(struct rte_ring *r);
 int rte_ring_set_water_mark(struct rte_ring *r, unsigned count);
 
 /**
- * Dump the status of the ring to the console.
+ * Dump the status of the ring to a file.
  *
  * @param f
  *   A pointer to a file for output
@@ -756,7 +757,7 @@ __rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table,
 
        /* copy in table */
        DEQUEUE_PTRS();
-       rte_smp_wmb();
+       rte_smp_rmb();
 
        __RING_STAT_ADD(r, deq_success, n);
        r->cons.tail = cons_next;
@@ -833,7 +834,7 @@ static inline int __attribute__((always_inline))
 rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
                      unsigned n)
 {
-       if (r->prod.sp_enqueue)
+       if (r->prod.single)
                return rte_ring_sp_enqueue_bulk(r, obj_table, n);
        else
                return rte_ring_mp_enqueue_bulk(r, obj_table, n);
@@ -900,7 +901,7 @@ rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
 static inline int __attribute__((always_inline))
 rte_ring_enqueue(struct rte_ring *r, void *obj)
 {
-       if (r->prod.sp_enqueue)
+       if (r->prod.single)
                return rte_ring_sp_enqueue(r, obj);
        else
                return rte_ring_mp_enqueue(r, obj);
@@ -971,7 +972,7 @@ rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
 static inline int __attribute__((always_inline))
 rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
 {
-       if (r->cons.sc_dequeue)
+       if (r->cons.single)
                return rte_ring_sc_dequeue_bulk(r, obj_table, n);
        else
                return rte_ring_mc_dequeue_bulk(r, obj_table, n);
@@ -1035,7 +1036,7 @@ rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
 static inline int __attribute__((always_inline))
 rte_ring_dequeue(struct rte_ring *r, void **obj_p)
 {
-       if (r->cons.sc_dequeue)
+       if (r->cons.single)
                return rte_ring_sc_dequeue(r, obj_p);
        else
                return rte_ring_mc_dequeue(r, obj_p);
@@ -1107,6 +1108,20 @@ rte_ring_free_count(const struct rte_ring *r)
        return (cons_tail - prod_tail - 1) & r->prod.mask;
 }
 
+/**
+ * Return the size of the ring.
+ *
+ * @param r
+ *   A pointer to the ring structure.
+ * @return
+ *   The number of elements which can be stored in the ring.
+ */
+static inline unsigned int
+rte_ring_get_size(const struct rte_ring *r)
+{
+       return r->prod.size;
+}
+
 /**
  * Dump the status of all rings on the console
  *
@@ -1188,7 +1203,7 @@ static inline unsigned __attribute__((always_inline))
 rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
                      unsigned n)
 {
-       if (r->prod.sp_enqueue)
+       if (r->prod.single)
                return rte_ring_sp_enqueue_burst(r, obj_table, n);
        else
                return rte_ring_mp_enqueue_burst(r, obj_table, n);
@@ -1256,7 +1271,7 @@ rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
 static inline unsigned __attribute__((always_inline))
 rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
 {
-       if (r->cons.sc_dequeue)
+       if (r->cons.single)
                return rte_ring_sc_dequeue_burst(r, obj_table, n);
        else
                return rte_ring_mc_dequeue_burst(r, obj_table, n);