bnx2x: Protect statistics ramrod and sequence number

Bug fix: Protect statistics ramrod sending code and a statistics counter update
with a spinlock. Otherwise there was a race condition that would allow sending
a statistics ramrods with the same sequence number or with sequence numbers not
in a natural order, which would cause a FW assert.

Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bnx2x_main.c

@@ -3789,6 +3789,8 @@ static void bnx2x_storm_stats_post(struct bnx2x *bp)
 		struct eth_query_ramrod_data ramrod_data = {0};
 		int i, rc;
 
+		spin_lock_bh(&bp->stats_lock);
+
 		ramrod_data.drv_counter = bp->stats_counter++;
 		ramrod_data.collect_port = bp->port.pmf ? 1 : 0;
 		for_each_queue(bp, i)
@@ -3802,6 +3804,8 @@ static void bnx2x_storm_stats_post(struct bnx2x *bp)
 			bp->spq_left++;
 			bp->stats_pending = 1;
 		}
+
+		spin_unlock_bh(&bp->stats_lock);
 	}
 }
 
@@ -4367,6 +4371,14 @@ static int bnx2x_storm_stats_update(struct bnx2x *bp)
 	struct host_func_stats *fstats = bnx2x_sp(bp, func_stats);
 	struct bnx2x_eth_stats *estats = &bp->eth_stats;
 	int i;
+	u16 cur_stats_counter;
+
+	/* Make sure we use the value of the counter
+	 * used for sending the last stats ramrod.
+	 */
+	spin_lock_bh(&bp->stats_lock);
+	cur_stats_counter = bp->stats_counter - 1;
+	spin_unlock_bh(&bp->stats_lock);
 
 	memcpy(&(fstats->total_bytes_received_hi),
 	       &(bnx2x_sp(bp, func_stats_base)->total_bytes_received_hi),
@@ -4394,25 +4406,22 @@ static int bnx2x_storm_stats_update(struct bnx2x *bp)
 		u32 diff;
 
 		/* are storm stats valid? */
-		if ((u16)(le16_to_cpu(xclient->stats_counter) + 1) !=
-							bp->stats_counter) {
+		if (le16_to_cpu(xclient->stats_counter) != cur_stats_counter) {
 			DP(BNX2X_MSG_STATS, "[%d] stats not updated by xstorm"
 			   "  xstorm counter (0x%x) != stats_counter (0x%x)\n",
-			   i, xclient->stats_counter, bp->stats_counter);
+			   i, xclient->stats_counter, cur_stats_counter + 1);
 			return -1;
 		}
-		if ((u16)(le16_to_cpu(tclient->stats_counter) + 1) !=
-							bp->stats_counter) {
+		if (le16_to_cpu(tclient->stats_counter) != cur_stats_counter) {
 			DP(BNX2X_MSG_STATS, "[%d] stats not updated by tstorm"
 			   "  tstorm counter (0x%x) != stats_counter (0x%x)\n",
-			   i, tclient->stats_counter, bp->stats_counter);
+			   i, tclient->stats_counter, cur_stats_counter + 1);
 			return -2;
 		}
-		if ((u16)(le16_to_cpu(uclient->stats_counter) + 1) !=
-							bp->stats_counter) {
+		if (le16_to_cpu(uclient->stats_counter) != cur_stats_counter) {
 			DP(BNX2X_MSG_STATS, "[%d] stats not updated by ustorm"
 			   "  ustorm counter (0x%x) != stats_counter (0x%x)\n",
-			   i, uclient->stats_counter, bp->stats_counter);
+			   i, uclient->stats_counter, cur_stats_counter + 1);
 			return -4;
 		}