[PATCH v3 net-next] octeontx2-af: add new mbox to support sync cycle on rx path

[Ratheesh Kannoth <rkannoth@marvell.com>]

From: Satha Rao <skoteshwar@marvell.com>

sync ensures that all packets that were in flight are flushed out to
memory. This can be used to assist in the tearing down of an active RQ.

To complete disabling RQs or disabling SMQ and its SQs, LF software
send mbox to AF to complete RX_SW_SYNC.

Both VF and PF and invoke this mbox.

Signed-off-by: Satha Rao <skoteshwar@marvell.com>
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>

---
v2 -> v3: Addressed Simon comments
	https://lore.kernel.org/netdev/20260715041239.2052888-1-rkannoth@marvell.com/
v1 -> v2: https://lore.kernel.org/netdev/20260715041239.2052888-1-rkannoth@marvell.com/
---
 .../net/ethernet/marvell/octeontx2/af/mbox.h  |  2 ++
 .../ethernet/marvell/octeontx2/af/rvu_nix.c   | 31 +++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/mbox.h b/drivers/net/ethernet/marvell/octeontx2/af/mbox.h
index 10552e9cf519..73f743e4a83d 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/mbox.h
+++ b/drivers/net/ethernet/marvell/octeontx2/af/mbox.h
@@ -362,6 +362,7 @@ M(NIX_CPT_BP_ENABLE,    0x8020, nix_cpt_bp_enable, nix_bp_cfg_req,	    \
 				nix_bp_cfg_rsp)				    \
 M(NIX_CPT_BP_DISABLE,   0x8021, nix_cpt_bp_disable, nix_bp_cfg_req,	    \
 				msg_rsp)				\
+M(NIX_RX_SW_SYNC,	0x8022, nix_rx_sw_sync, msg_req, msg_rsp)		\
 M(NIX_READ_INLINE_IPSEC_CFG, 0x8023, nix_read_inline_ipsec_cfg,		\
 				msg_req, nix_inline_ipsec_cfg)		\
 M(NIX_MCAST_GRP_CREATE,	0x802b, nix_mcast_grp_create, nix_mcast_grp_create_req,	\
@@ -952,6 +953,7 @@ enum nix_af_status {
 	NIX_AF_ERR_INVALID_MCAST_GRP	= -436,
 	NIX_AF_ERR_INVALID_MCAST_DEL_REQ = -437,
 	NIX_AF_ERR_NON_CONTIG_MCE_LIST = -438,
+	NIX_AF_ERR_RX_SW_SYNC_FAIL	= -439,
 };
 
 /* For NIX RX vtag action  */
diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c
index dade7bb6deb7..e397c8cedbc7 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c
@@ -269,15 +269,19 @@ u32 convert_bytes_to_dwrr_mtu(u32 bytes)
 	return 0;
 }
 
-static void nix_rx_sync(struct rvu *rvu, int blkaddr)
+static int nix_rx_sync(struct rvu *rvu, int blkaddr)
 {
 	int err;
 
+	mutex_lock(&rvu->rsrc_lock);
+
 	/* Sync all in flight RX packets to LLC/DRAM */
 	rvu_write64(rvu, blkaddr, NIX_AF_RX_SW_SYNC, BIT_ULL(0));
 	err = rvu_poll_reg(rvu, blkaddr, NIX_AF_RX_SW_SYNC, BIT_ULL(0), true);
-	if (err)
+	if (err) {
 		dev_err(rvu->dev, "SYNC1: NIX RX software sync failed\n");
+		goto unlock;
+	}
 
 	/* SW_SYNC ensures all existing transactions are finished and pkts
 	 * are written to LLC/DRAM, queues should be teared down after
@@ -289,6 +293,10 @@ static void nix_rx_sync(struct rvu *rvu, int blkaddr)
 	err = rvu_poll_reg(rvu, blkaddr, NIX_AF_RX_SW_SYNC, BIT_ULL(0), true);
 	if (err)
 		dev_err(rvu->dev, "SYNC2: NIX RX software sync failed\n");
+
+unlock:
+	mutex_unlock(&rvu->rsrc_lock);
+	return err;
 }
 
 static bool is_valid_txschq(struct rvu *rvu, int blkaddr,
@@ -6336,6 +6344,25 @@ int rvu_mbox_handler_nix_bandprof_get_hwinfo(struct rvu *rvu, struct msg_req *re
 	return 0;
 }
 
+int rvu_mbox_handler_nix_rx_sw_sync(struct rvu *rvu, struct msg_req *req,
+				    struct msg_rsp *rsp)
+{
+	int blkaddr, nixlf, err;
+
+	/* NIX_AF_RX_SW_SYNC is global per NIX block; nix_rx_sync() serializes
+	 * access under rvu->rsrc_lock across mbox and teardown paths.
+	 */
+	err = nix_get_nixlf(rvu, req->hdr.pcifunc, &nixlf, &blkaddr);
+	if (err)
+		return err;
+
+	err = nix_rx_sync(rvu, blkaddr);
+	if (err)
+		return NIX_AF_ERR_RX_SW_SYNC_FAIL;
+
+	return 0;
+}
+
 static struct nix_mcast_grp_elem *rvu_nix_mcast_find_grp_elem(struct nix_mcast_grp *mcast_grp,
 							      u32 mcast_grp_idx)
 {
-- 
2.43.0