[dpdk-dev] [PATCH v2] net/mlx5: add power monitoring support

[Alexander Kozyrev <akozyrev@nvidia.com>]

Support the PMD power management API in MLX5 driver.
The monitor policy of this API puts a CPU core to sleep until
a data in some monitored memory address is changed by the NIC.
Implement the get_monitor_addr function to return an address
of a CQE owner bit to monitor the arrival of a new packet.

Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
---
v2: fixed check for empty CQE array

 doc/guides/rel_notes/release_21_05.rst |  4 ++++
 drivers/net/mlx5/mlx5.c                |  2 ++
 drivers/net/mlx5/mlx5_rxtx.c           | 19 +++++++++++++++++++
 drivers/net/mlx5/mlx5_rxtx.h           |  1 +
 4 files changed, 26 insertions(+)

diff --git a/doc/guides/rel_notes/release_21_05.rst b/doc/guides/rel_notes/release_21_05.rst
index 19cec62c73..0894206b14 100644
--- a/doc/guides/rel_notes/release_21_05.rst
+++ b/doc/guides/rel_notes/release_21_05.rst
@@ -97,6 +97,10 @@ New Features
 
   * Added flow filter to support GTPU inner L3/L4 fields matching.
 
+* **Updated Mellanox mlx5 driver.**
+
+  * Added support for the monitor policy of Power Management API.
+
 * **Updated NXP DPAA driver.**
 
   * Added support for shared ethernet interface.
diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 9557d06afa..c7ac224fed 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -1518,6 +1518,7 @@ const struct eth_dev_ops mlx5_dev_ops = {
 	.hairpin_queue_peer_update = mlx5_hairpin_queue_peer_update,
 	.hairpin_queue_peer_bind = mlx5_hairpin_queue_peer_bind,
 	.hairpin_queue_peer_unbind = mlx5_hairpin_queue_peer_unbind,
+	.get_monitor_addr = mlx5_get_monitor_addr,
 };
 
 /* Available operations from secondary process. */
@@ -1602,6 +1603,7 @@ const struct eth_dev_ops mlx5_dev_ops_isolate = {
 	.hairpin_queue_peer_update = mlx5_hairpin_queue_peer_update,
 	.hairpin_queue_peer_bind = mlx5_hairpin_queue_peer_bind,
 	.hairpin_queue_peer_unbind = mlx5_hairpin_queue_peer_unbind,
+	.get_monitor_addr = mlx5_get_monitor_addr,
 };
 
 /**
diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index c76b9951bc..1a87acb4d1 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -712,6 +712,25 @@ mlx5_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	return rx_queue_count(rxq);
 }
 
+int mlx5_get_monitor_addr(void *rx_queue, struct rte_power_monitor_cond *pmc)
+{
+	struct mlx5_rxq_data *rxq = rx_queue;
+	const unsigned int cqe_num = 1 << rxq->cqe_n;
+	const unsigned int cqe_mask = cqe_num - 1;
+	const uint16_t idx = rxq->cq_ci & cqe_num;
+	volatile struct mlx5_cqe *cqe = &(*rxq->cqes)[rxq->cq_ci & cqe_mask];
+
+	if (unlikely(rxq->cqes == NULL)) {
+		rte_errno = EINVAL;
+		return -rte_errno;
+	}
+	pmc->addr = &cqe->op_own;
+	pmc->val =  !!idx;
+	pmc->mask = MLX5_CQE_OWNER_MASK;
+	pmc->size = sizeof(uint8_t);
+	return 0;
+}
+
 #define MLX5_SYSTEM_LOG_DIR "/var/log"
 /**
  * Dump debug information to log file.
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 4f0fda0dec..6b8e28cea7 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -442,6 +442,7 @@ int mlx5_rx_burst_mode_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 			   struct rte_eth_burst_mode *mode);
 int mlx5_tx_burst_mode_get(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 			   struct rte_eth_burst_mode *mode);
+int mlx5_get_monitor_addr(void *rx_queue, struct rte_power_monitor_cond *pmc);
 
 /* Vectorized version of mlx5_rxtx.c */
 int mlx5_rxq_check_vec_support(struct mlx5_rxq_data *rxq_data);
-- 
2.24.1