QOS is designed to create a new send queue whenever  a class
is created, ensuring proper shaping and scheduling. However,
when multiple send queues are created and deleted in a loop,
SMMU errors are observed.

This patch addresses the issue by performing an data cache sync
during the teardown of QOS send queues.

Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
---
 .../ethernet/marvell/octeontx2/nic/qos_sq.c   | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/qos_sq.c b/drivers/net/ethernet/marvell/octeontx2/nic/qos_sq.c
index c5dbae0e513b..58d572ce08ef 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/qos_sq.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/qos_sq.c
@@ -256,6 +256,26 @@ int otx2_qos_enable_sq(struct otx2_nic *pfvf, int qidx)
 	return err;
 }
 
+static int otx2_qos_nix_npa_ndc_sync(struct otx2_nic *pfvf)
+{
+	struct ndc_sync_op *req;
+	int rc;
+
+	mutex_lock(&pfvf->mbox.lock);
+
+	req = otx2_mbox_alloc_msg_ndc_sync_op(&pfvf->mbox);
+	if (!req) {
+		mutex_unlock(&pfvf->mbox.lock);
+		return -ENOMEM;
+	}
+
+	req->nix_lf_tx_sync = true;
+	req->npa_lf_sync = true;
+	rc = otx2_sync_mbox_msg(&pfvf->mbox);
+	mutex_unlock(&pfvf->mbox.lock);
+	return rc;
+}
+
 void otx2_qos_disable_sq(struct otx2_nic *pfvf, int qidx)
 {
 	struct otx2_qset *qset = &pfvf->qset;
@@ -285,6 +305,8 @@ void otx2_qos_disable_sq(struct otx2_nic *pfvf, int qidx)
 
 	otx2_qos_sqb_flush(pfvf, sq_idx);
 	otx2_smq_flush(pfvf, otx2_get_smq_idx(pfvf, sq_idx));
+	/* NIX/NPA NDC sync */
+	otx2_qos_nix_npa_ndc_sync(pfvf);
 	otx2_cleanup_tx_cqes(pfvf, cq);
 
 	mutex_lock(&pfvf->mbox.lock);
-- 
2.34.1

On Tue, May 20, 2025 at 02:52:48PM +0530, Hariprasad Kelam wrote:
> QOS is designed to create a new send queue whenever  a class
> is created, ensuring proper shaping and scheduling. However,
> when multiple send queues are created and deleted in a loop,
> SMMU errors are observed.
> 
> This patch addresses the issue by performing an data cache sync
> during the teardown of QOS send queues.
> 
> Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>

Hi Hariprasad,

This feels like a fix and if so:
* Warrants a Fixes tag
* Should also be targeted at net rather than net-next if it fixes a problem
  present in net

On 2025-05-20 at 22:36:15, Simon Horman (horms@kernel.org) wrote:
> On Tue, May 20, 2025 at 02:52:48PM +0530, Hariprasad Kelam wrote:
> > QOS is designed to create a new send queue whenever  a class
> > is created, ensuring proper shaping and scheduling. However,
> > when multiple send queues are created and deleted in a loop,
> > SMMU errors are observed.
> > 
> > This patch addresses the issue by performing an data cache sync
> > during the teardown of QOS send queues.
> > 
> > Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
> 
> Hi Hariprasad,
> 
> This feels like a fix and if so:
> * Warrants a Fixes tag
> * Should also be targeted at net rather than net-next if it fixes a problem
>   present in net
> 
   Ack, will post to net