qed: fix ll2 establishment during load of RDMA driver

If stats ID of a LL2 (light l2) queue exceeds than the total amount
of statistics counters, it may cause system crash upon enabling
RDMA on all PFs.

This patch makes sure that the stats ID of the LL2 queue doesn't exceed
the max allowed value.
Signed-off-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Shai Malin <smalin@marvell.com>
Signed-off-by: Omkar Kulkarni <okulkarni@marvell.com>
Signed-off-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_ll2.c

@@ -44,6 +44,8 @@
 #define QED_LL2_TX_SIZE (256)
 #define QED_LL2_RX_SIZE (4096)
 
+#define QED_LL2_INVALID_STATS_ID        0xff
+
 struct qed_cb_ll2_info {
 	int rx_cnt;
 	u32 rx_size;
@@ -63,6 +65,29 @@ struct qed_ll2_buffer {
 	dma_addr_t phys_addr;
 };
 
+static u8 qed_ll2_handle_to_stats_id(struct qed_hwfn *p_hwfn,
+				     u8 ll2_queue_type, u8 qid)
+{
+	u8 stats_id;
+
+	/* For legacy (RAM based) queues, the stats_id will be set as the
+	 * queue_id. Otherwise (context based queue), it will be set to
+	 * the "abs_pf_id" offset from the end of the RAM based queue IDs.
+	 * If the final value exceeds the total counters amount, return
+	 * INVALID value to indicate that the stats for this connection should
+	 * be disabled.
+	 */
+	if (ll2_queue_type == QED_LL2_RX_TYPE_LEGACY)
+		stats_id = qid;
+	else
+		stats_id = MAX_NUM_LL2_RX_RAM_QUEUES + p_hwfn->abs_pf_id;
+
+	if (stats_id < MAX_NUM_LL2_TX_STATS_COUNTERS)
+		return stats_id;
+	else
+		return QED_LL2_INVALID_STATS_ID;
+}
+
 static void qed_ll2b_complete_tx_packet(void *cxt,
 					u8 connection_handle,
 					void *cookie,
@@ -1546,7 +1571,7 @@ int qed_ll2_establish_connection(void *cxt, u8 connection_handle)
 	int rc = -EINVAL;
 	u32 i, capacity;
 	size_t desc_size;
-	u8 qid;
+	u8 qid, stats_id;
 
 	p_ptt = qed_ptt_acquire(p_hwfn);
 	if (!p_ptt)
@@ -1612,12 +1637,26 @@ int qed_ll2_establish_connection(void *cxt, u8 connection_handle)
 
 	qid = qed_ll2_handle_to_queue_id(p_hwfn, connection_handle,
 					 p_ll2_conn->input.rx_conn_type);
+	stats_id = qed_ll2_handle_to_stats_id(p_hwfn,
+					      p_ll2_conn->input.rx_conn_type,
+					      qid);
 	p_ll2_conn->queue_id = qid;
-	p_ll2_conn->tx_stats_id = qid;
+	p_ll2_conn->tx_stats_id = stats_id;
 
-	DP_VERBOSE(p_hwfn, QED_MSG_LL2,
-		   "Establishing ll2 queue. PF %d ctx_based=%d abs qid=%d\n",
-		   p_hwfn->rel_pf_id, p_ll2_conn->input.rx_conn_type, qid);
+	/* If there is no valid stats id for this connection, disable stats */
+	if (p_ll2_conn->tx_stats_id == QED_LL2_INVALID_STATS_ID) {
+		p_ll2_conn->tx_stats_en = 0;
+		DP_VERBOSE(p_hwfn,
+			   QED_MSG_LL2,
+			   "Disabling stats for queue %d - not enough counters\n",
+			   qid);
+	}
+
+	DP_VERBOSE(p_hwfn,
+		   QED_MSG_LL2,
+		   "Establishing ll2 queue. PF %d ctx_bsaed=%d abs qid=%d stats_id=%d\n",
+		   p_hwfn->rel_pf_id,
+		   p_ll2_conn->input.rx_conn_type, qid, stats_id);
 
 	if (p_ll2_conn->input.rx_conn_type == QED_LL2_RX_TYPE_LEGACY) {
 		p_rx->set_prod_addr =