[PATCH v4 18/31] net/ena/base: check for existing keep alive notification

[<shaibran@amazon.com>]

From: Shai Brandes <shaibran@amazon.com>

This commit adds an API to query the aenq on whether
there is a pending keep alive notification.

Signed-off-by: Shai Brandes <shaibran@amazon.com>
Reviewed-by: Amit Bernstein <amitbern@amazon.com>
---
 drivers/net/ena/base/ena_com.c | 39 ++++++++++++++++++++++++++++++++++
 drivers/net/ena/base/ena_com.h | 10 +++++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/net/ena/base/ena_com.c b/drivers/net/ena/base/ena_com.c
index 8e9c112715..f9613f7807 100644
--- a/drivers/net/ena/base/ena_com.c
+++ b/drivers/net/ena/base/ena_com.c
@@ -2456,6 +2456,45 @@ void ena_com_aenq_intr_handler(struct ena_com_dev *ena_dev, void *data)
 	mmiowb();
 }
 
+bool ena_com_aenq_has_keep_alive(struct ena_com_dev *ena_dev)
+{
+	struct ena_admin_aenq_common_desc *aenq_common;
+	struct ena_com_aenq *aenq = &ena_dev->aenq;
+	struct ena_admin_aenq_entry *aenq_e;
+	u8 phase = aenq->phase;
+	u16 masked_head;
+
+	masked_head = aenq->head & (aenq->q_depth - 1);
+	aenq_e = &aenq->entries[masked_head]; /* Get first entry */
+	aenq_common = &aenq_e->aenq_common_desc;
+
+	/* Go over all the events */
+	while ((READ_ONCE8(aenq_common->flags) &
+		ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) == phase) {
+		/* Make sure the device finished writing the rest of the descriptor
+		 * before reading it.
+		 */
+		dma_rmb();
+
+		if (aenq_common->group == ENA_ADMIN_KEEP_ALIVE)
+			return true;
+
+		/* Get next event entry */
+		masked_head++;
+
+		if (unlikely(masked_head == aenq->q_depth)) {
+			masked_head = 0;
+			phase = !phase;
+		}
+
+		aenq_e = &aenq->entries[masked_head];
+		aenq_common = &aenq_e->aenq_common_desc;
+	}
+
+	return false;
+}
+
+
 int ena_com_dev_reset(struct ena_com_dev *ena_dev,
 		      enum ena_regs_reset_reason_types reset_reason)
 {
diff --git a/drivers/net/ena/base/ena_com.h b/drivers/net/ena/base/ena_com.h
index c999cd2381..737747f64b 100644
--- a/drivers/net/ena/base/ena_com.h
+++ b/drivers/net/ena/base/ena_com.h
@@ -639,6 +639,16 @@ void ena_com_admin_q_comp_intr_handler(struct ena_com_dev *ena_dev);
  */
 void ena_com_aenq_intr_handler(struct ena_com_dev *ena_dev, void *data);
 
+/* ena_com_aenq_has_keep_alive - Retrieve if there is a keep alive notification in the aenq
+ * @ena_dev: ENA communication layer struct
+ *
+ * This method goes over the async event notification queue and returns if there
+ * is a keep alive notification.
+ *
+ * @return - true if there is a keep alive notification in the aenq or false otherwise
+ */
+bool ena_com_aenq_has_keep_alive(struct ena_com_dev *ena_dev);
+
 /* ena_com_abort_admin_commands - Abort all the outstanding admin commands.
  * @ena_dev: ENA communication layer struct
  *
-- 
2.17.1