[PATCH] net/ring: add umonitor callback

[Herakliusz Lipiec <herakliusz.lipiec@intel.com>]

Currently ring pmd does not support ``rte_power_monitor`` api.
This patch adds support by adding umonitor callback that is called
whenever we enter sleep state and need to check if it is time to wake
up.

Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec@intel.com>
---
 drivers/net/ring/rte_eth_ring.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/net/ring/rte_eth_ring.c b/drivers/net/ring/rte_eth_ring.c
index cfb81da5fe..1bb6b196cb 100644
--- a/drivers/net/ring/rte_eth_ring.c
+++ b/drivers/net/ring/rte_eth_ring.c
@@ -284,6 +284,28 @@ eth_dev_close(struct rte_eth_dev *dev)
 	return ret;
 }
 
+static int ring_monitor_callback(const uint64_t value,
+		const uint64_t arg[RTE_POWER_MONITOR_OPAQUE_SZ])
+{
+	/* Check if the head pointer has changed */
+	return value != arg[0];
+}
+
+static int
+eth_get_monitor_addr(void* rx_queue, struct rte_power_monitor_cond *pmc)
+{
+	struct rte_ring *rng = ((struct ring_queue*) rx_queue)->rng;
+
+	/* Monitor ring head since if head moves
+	 * there are packets to transmit
+	 * */
+	pmc->addr = &rng->prod.head;
+	pmc->size = sizeof(rng->prod.head);
+	pmc->opaque[0] = rng->prod.head;
+	pmc->fn = ring_monitor_callback;
+	return 0;
+}
+
 static const struct eth_dev_ops ops = {
 	.dev_close = eth_dev_close,
 	.dev_start = eth_dev_start,
@@ -303,6 +325,7 @@ static const struct eth_dev_ops ops = {
 	.promiscuous_disable = eth_promiscuous_disable,
 	.allmulticast_enable = eth_allmulticast_enable,
 	.allmulticast_disable = eth_allmulticast_disable,
+	.get_monitor_addr = eth_get_monitor_addr,
 };
 
 static int
-- 
2.36.1