[dpdk-dev] [PATCH v2 2/3] ethdev: add device iterator

[Gaetan Rivet <gaetan.rivet@6wind.com>]

This iterator helps applications iterate over the device list and skip
holes caused by invalid or detached devices.

Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
---
 lib/librte_ether/rte_ethdev.c | 17 ++++++++++++++---
 lib/librte_ether/rte_ethdev.h | 21 ++++++++++++++++++++-
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 90d0713..ca7af35 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -138,6 +138,19 @@ enum {
 	STAT_QMAP_RX
 };
 
+uint8_t
+rte_eth_find_next(uint8_t port_id)
+{
+	while (port_id < RTE_MAX_ETHPORTS &&
+	       rte_eth_devices[port_id].state != RTE_ETH_DEV_ATTACHED)
+		port_id++;
+
+	if (port_id >= RTE_MAX_ETHPORTS)
+		return RTE_MAX_ETHPORTS;
+
+	return port_id;
+}
+
 static void
 rte_eth_dev_data_alloc(void)
 {
@@ -424,9 +437,7 @@ rte_eth_dev_get_port_by_name(const char *name, uint8_t *port_id)
 		return -ENODEV;
 
 	*port_id = RTE_MAX_ETHPORTS;
-
-	for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
-
+	RTE_ETH_FOREACH_DEV(i) {
 		if (!strncmp(name,
 			rte_eth_dev_data[i].name, strlen(name))) {
 
diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index b9531f3..bed7dff 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -1736,6 +1736,25 @@ struct rte_eth_dev_data {
 extern struct rte_eth_dev rte_eth_devices[];
 
 /**
+ * Iterates over valid ethdev ports.
+ *
+ * @param: port_id
+ *   The id of the next possible valid port.
+ * @return
+ *   Next valid port id, RTE_MAX_ETHPORTS if there is none.
+ */
+uint8_t rte_eth_find_next(uint8_t port_id);
+
+/**
+ * Macro to iterate over all enabled ethdev ports.
+ */
+#define RTE_ETH_FOREACH_DEV(p)					\
+	for (p = rte_eth_find_next(0);				\
+	     (unsigned int)p < (unsigned int)RTE_MAX_ETHPORTS;	\
+	     p = rte_eth_find_next(p + 1))
+
+
+/**
  * Get the total number of Ethernet devices that have been successfully
  * initialized by the [matching] Ethernet driver during the PCI probing phase.
  * All devices whose port identifier is in the range
@@ -1743,7 +1762,7 @@ extern struct rte_eth_dev rte_eth_devices[];
  * immediately after invoking rte_eal_init().
  * If the application unplugs a port using hotplug function, The enabled port
  * numbers may be noncontiguous. In the case, the applications need to manage
- * enabled port by themselves.
+ * enabled port by using the ``RTE_ETH_FOREACH_DEV()`` macro.
  *
  * @return
  *   - The total number of usable Ethernet devices.
-- 
2.1.4