[dpdk-dev,02/15] eventdev: add APIs for extended stats

diff --git a/lib/librte_eventdev/rte_eventdev.c b/lib/librte_eventdev/rte_eventdev.c
index c8f3e94..ca11d54 100644
--- a/lib/librte_eventdev/rte_eventdev.c
+++ b/lib/librte_eventdev/rte_eventdev.c
@@ -920,6 +920,70 @@  rte_event_dev_dump(uint8_t dev_id, FILE *f)
 
 }
 
+static int
+get_xstats_count(uint8_t dev_id)
+{
+	struct rte_eventdev *dev = &rte_eventdevs[dev_id];
+	if (dev->dev_ops->get_xstat_names != NULL)
+		return (*dev->dev_ops->get_xstat_names)(dev, NULL, 0);
+	return 0;
+}
+
+int
+rte_event_dev_get_xstat_names(uint8_t dev_id,
+	struct rte_event_dev_xstat_name *xstats_names,
+	unsigned int size)
+{
+	RTE_EVENTDEV_VALID_DEVID_OR_ERR_RET(dev_id, -EINVAL);
+	const int cnt_expected_entries = get_xstats_count(dev_id);
+	if (xstats_names == NULL || cnt_expected_entries < 0 ||
+			(int)size < cnt_expected_entries)
+		return cnt_expected_entries;
+
+	/* dev_id checked in get_xstats_count() */
+	const struct rte_eventdev *dev = &rte_eventdevs[dev_id];
+
+	if (dev->dev_ops->get_xstat_names != NULL)
+		return (*dev->dev_ops->get_xstat_names)(dev,
+				xstats_names, size);
+
+	return 0;
+}
+
+/* retrieve eventdev extended statistics */
+int
+rte_event_dev_get_xstats(uint8_t dev_id, const unsigned int ids[],
+	uint64_t values[], unsigned int n)
+{
+	RTE_EVENTDEV_VALID_DEVID_OR_ERR_RET(dev_id, -EINVAL);
+	const struct rte_eventdev *dev = &rte_eventdevs[dev_id];
+
+	/* implemented by the driver */
+	if (dev->dev_ops->get_xstats != NULL)
+		return (*dev->dev_ops->get_xstats)(dev, ids, values, n);
+	return 0;
+}
+
+uint64_t
+rte_event_dev_get_xstat_by_name(uint8_t dev_id, const char *name,
+		unsigned int *id)
+{
+	const struct rte_eventdev *dev = &rte_eventdevs[dev_id];
+	unsigned int temp = -1;
+
+	if (id != NULL)
+		*id = (unsigned int)-1;
+	else
+		id = &temp; /* ensure driver never gets a NULL value */
+
+	RTE_EVENTDEV_VALID_DEVID_OR_ERR_RET(dev_id, 0);
+
+	/* implemented by driver */
+	if (dev->dev_ops->get_xstat_by_name != NULL)
+		return (*dev->dev_ops->get_xstat_by_name)(dev, name, id);
+	return 0;
+}
+
 int
 rte_event_dev_start(uint8_t dev_id)
 {
diff --git a/lib/librte_eventdev/rte_eventdev.h b/lib/librte_eventdev/rte_eventdev.h
index c2f9310..681cbfa 100644
--- a/lib/librte_eventdev/rte_eventdev.h
+++ b/lib/librte_eventdev/rte_eventdev.h
@@ -1401,6 +1401,81 @@  rte_event_port_links_get(uint8_t dev_id, uint8_t port_id,
 int
 rte_event_dev_dump(uint8_t dev_id, FILE *f);
 
+/** Maximum name length for extended statistics counters */
+#define RTE_EVENT_DEV_XSTAT_NAME_SIZE 64
+
+/**
+ * A name-key lookup element for extended statistics.
+ *
+ * This structure is used to map between names and ID numbers
+ * for extended ethdev statistics.
+ */
+struct rte_event_dev_xstat_name {
+	char name[RTE_EVENT_DEV_XSTAT_NAME_SIZE];
+};
+
+/**
+ * Retrieve names of extended statistics of an event device.
+ *
+ * @param dev_id
+ *   The identifier of the event device.
+ * @param xstat_names
+ *  Block of memory to insert names into. Must be at least size in capacity.
+ *  If set to NULL, function returns required capacity.
+ * @param size
+ *  Capacity of xstat_names (number of names).
+ * @return
+ *   - positive value lower or equal to size: success. The return value
+ *     is the number of entries filled in the stats table.
+ *   - positive value higher than size: error, the given statistics table
+ *     is too small. The return value corresponds to the size that should
+ *     be given to succeed. The entries in the table are not valid and
+ *     shall not be used by the caller.
+ *   - negative value on error (invalid port id)
+ */
+int
+rte_event_dev_get_xstat_names(uint8_t dev_id,
+		struct rte_event_dev_xstat_name *xstat_names,
+		unsigned int size);
+
+/**
+ * Retrieve extended statistics of an event device.
+ *
+ * @param dev_id
+ *   The identifier of the device.
+ * @param ids
+ *   The id numbers of the stats to get. The ids can be got from the stat
+ *   position in the stat list from rte_event_dev_get_xstat_names(), or
+ *   by using rte_eventdev_get_xstat_by_name()
+ * @param values
+ *   The values for each stats request by ID.
+ * @param n
+ *   The number of stats requested
+ * @return
+ *   Number of stat entries filled into the values array
+ */
+int
+rte_event_dev_get_xstats(uint8_t dev_id, const unsigned int ids[],
+		uint64_t values[], unsigned int n);
+
+/**
+ * Retrieve the value of a single stat by requesting it by name.
+ *
+ * @param dev_id
+ *   The identifier of the device
+ * @param name
+ *   The stat name to retrieve
+ * @param id
+ *   If non-NULL, the numerical id of the stat will be returned, so that further
+ *   requests for the stat can be got using rte_eventdev_xstats_get, which will
+ *   be faster as it doesn't need to scan a list of names for the stat.
+ *   If the stat cannot be found, the id returned will be (unsigned)-1.
+ * @return
+ *   The stat value, or -1 if not found.
+ */
+uint64_t
+rte_event_dev_get_xstat_by_name(uint8_t dev_id, const char *name, unsigned int *id);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eventdev/rte_eventdev_pmd.h b/lib/librte_eventdev/rte_eventdev_pmd.h
index c84c9a2..7a6229d 100644
--- a/lib/librte_eventdev/rte_eventdev_pmd.h
+++ b/lib/librte_eventdev/rte_eventdev_pmd.h
@@ -418,6 +418,59 @@  typedef void (*eventdev_dequeue_timeout_ticks_t)(struct rte_eventdev *dev,
  */
 typedef void (*eventdev_dump_t)(struct rte_eventdev *dev, FILE *f);
 
+/**
+ * Retrieve a set of statistics from device
+ *
+ * @param dev
+ *   Event device pointer
+ * @param ids
+ *   The stat ids to retrieve
+ * @param values
+ *   The returned stat values
+ * @param n
+ *   The number of id values and entries in the values array
+ * @return
+ *   The number of stat values successfully filled into the values array
+ */
+typedef int (*eventdev_get_xstats_t)(const struct rte_eventdev *dev,
+	const unsigned int ids[], uint64_t values[], unsigned int n);
+
+/**
+ * Get names of extended stats of an event device
+ *
+ * @param dev
+ *   Event device pointer
+ * @param xstat_names
+ *   Array of name values to be filled in
+ * @param size
+ *   Number of values in the xstat_names array
+ * @return
+ *   When size >= the number of stats, return the number of stat values filled
+ *   into the array.
+ *   When size < the number of available stats, return the number of stats
+ *   values, and do not fill in any data into xstat_names.
+ */
+typedef int (*eventdev_get_xstat_names_t)(const struct rte_eventdev *dev,
+	struct rte_event_dev_xstat_name *xstat_names, unsigned int size);
+
+/**
+ * Get value of one stats and optionally return its id
+ *
+ * @param dev
+ *   Event device pointer
+ * @param name
+ *   The name of the stat to retrieve
+ * @param id
+ *   Pointer to an unsigned int where we store the stat-id for future reference.
+ *   This pointer may be null if the id is not required.
+ * @return
+ *   The value of the stat, or (uint64_t)-1 if the stat is not found.
+ *   If the stat is not found, the id value will be returned as (unsigned)-1,
+ *   if id pointer is non-NULL
+ */
+typedef uint64_t (*eventdev_get_xstat_by_name)(const struct rte_eventdev *dev,
+		const char *name, unsigned int *id);
+
 /** Event device operations function pointer table */
 struct rte_eventdev_ops {
 	eventdev_info_get_t dev_infos_get;	/**< Get device info. */
@@ -448,6 +501,11 @@  struct rte_eventdev_ops {
 	/**< Converts ns to *timeout_ticks* value for rte_event_dequeue() */
 	eventdev_dump_t dump;
 	/* Dump internal information */
+
+	eventdev_get_xstats_t get_xstats;    /**< Get extended device statistics. */
+	eventdev_get_xstat_names_t get_xstat_names; /**< Get names of extended stats. */
+	eventdev_get_xstat_by_name get_xstat_by_name; /**< Get one value by name */
+
 };
 
 /**
diff --git a/lib/librte_eventdev/rte_eventdev_version.map b/lib/librte_eventdev/rte_eventdev_version.map
index 68b8c81..b138eb3 100644
--- a/lib/librte_eventdev/rte_eventdev_version.map
+++ b/lib/librte_eventdev/rte_eventdev_version.map
@@ -12,6 +12,9 @@  DPDK_17.02 {
 	rte_event_dev_stop;
 	rte_event_dev_close;
 	rte_event_dev_dump;
+	rte_event_dev_get_xstats;
+	rte_event_dev_get_xstat_names;
+	rte_event_dev_get_xstat_by_name;
 
 	rte_event_port_default_conf_get;
 	rte_event_port_setup;