[PATCH net] net: mana: Fix error handling in mana_create_txq/rxq's NAPI cleanup

[Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxxxxxxxx>]

Currently napi_disable() gets called during rxq and txq cleanup,
even before napi is enabled and hrtimer is initialized. It causes
kernel panic.

? page_fault_oops+0x136/0x2b0
  ? page_counter_cancel+0x2e/0x80
  ? do_user_addr_fault+0x2f2/0x640
  ? refill_obj_stock+0xc4/0x110
  ? exc_page_fault+0x71/0x160
  ? asm_exc_page_fault+0x27/0x30
  ? __mmdrop+0x10/0x180
  ? __mmdrop+0xec/0x180
  ? hrtimer_active+0xd/0x50
  hrtimer_try_to_cancel+0x2c/0xf0
  hrtimer_cancel+0x15/0x30
  napi_disable+0x65/0x90
  mana_destroy_rxq+0x4c/0x2f0
  mana_create_rxq.isra.0+0x56c/0x6d0
  ? mana_uncfg_vport+0x50/0x50
  mana_alloc_queues+0x21b/0x320
  ? skb_dequeue+0x5f/0x80

Fixes: e1b5683ff62e ("net: mana: Move NAPI from EQ to CQ")

Signed-off-by: Souradeep Chakrabarti <schakrabarti@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 41 +++++++++++++------
 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 39f56973746d..882b05e087b9 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1862,7 +1862,7 @@ static void mana_deinit_txq(struct mana_port_context *apc, struct mana_txq *txq)
 	mana_gd_destroy_queue(gd->gdma_context, txq->gdma_sq);
 }
 
-static void mana_destroy_txq(struct mana_port_context *apc)
+static void mana_cleanup_napi_txq(struct mana_port_context *apc)
 {
 	struct napi_struct *napi;
 	int i;
@@ -1875,7 +1875,17 @@ static void mana_destroy_txq(struct mana_port_context *apc)
 		napi_synchronize(napi);
 		napi_disable(napi);
 		netif_napi_del(napi);
+	}
+}
+
+static void mana_destroy_txq(struct mana_port_context *apc)
+{
+	int i;
+
+	if (!apc->tx_qp)
+		return;
 
+	for (i = 0; i < apc->num_queues; i++) {
 		mana_destroy_wq_obj(apc, GDMA_SQ, apc->tx_qp[i].tx_object);
 
 		mana_deinit_cq(apc, &apc->tx_qp[i].tx_cq);
@@ -2007,6 +2017,21 @@ static int mana_create_txq(struct mana_port_context *apc,
 	return err;
 }
 
+static void mana_cleanup_napi_rxq(struct mana_port_context *apc,
+				  struct mana_rxq *rxq, bool validate_state)
+{
+	struct napi_struct *napi;
+
+	if (!rxq)
+		return;
+
+	napi = &rxq->rx_cq.napi;
+	if (validate_state)
+		napi_synchronize(napi);
+	napi_disable(napi);
+	netif_napi_del(napi);
+}
+
 static void mana_destroy_rxq(struct mana_port_context *apc,
 			     struct mana_rxq *rxq, bool validate_state)
 
@@ -2014,24 +2039,14 @@ static void mana_destroy_rxq(struct mana_port_context *apc,
 	struct gdma_context *gc = apc->ac->gdma_dev->gdma_context;
 	struct mana_recv_buf_oob *rx_oob;
 	struct device *dev = gc->dev;
-	struct napi_struct *napi;
 	struct page *page;
 	int i;
 
 	if (!rxq)
 		return;
 
-	napi = &rxq->rx_cq.napi;
-
-	if (validate_state)
-		napi_synchronize(napi);
-
-	napi_disable(napi);
-
 	xdp_rxq_info_unreg(&rxq->xdp_rxq);
 
-	netif_napi_del(napi);
-
 	mana_destroy_wq_obj(apc, GDMA_RQ, rxq->rxobj);
 
 	mana_deinit_cq(apc, &rxq->rx_cq);
@@ -2336,11 +2351,11 @@ static void mana_destroy_vport(struct mana_port_context *apc)
 		rxq = apc->rxqs[rxq_idx];
 		if (!rxq)
 			continue;
-
+		mana_cleanup_napi_rxq(apc, rxq, true);
 		mana_destroy_rxq(apc, rxq, true);
 		apc->rxqs[rxq_idx] = NULL;
 	}
-
+	mana_cleanup_napi_txq(apc);
 	mana_destroy_txq(apc);
 	mana_uncfg_vport(apc);
 
-- 
2.34.1