net/bnxt: detect bad opaque in Rx completion

There is a rare hardware bug that can cause a bad opaque value in the RX
or TPA start completion. When this happens, the hardware may have used the
same buffer twice for 2 Rx packets.  In addition, the driver might also
crash later using the bad opaque as an index into the ring.

The Rx opaque value is predictable and is always monotonically increasing.
The workaround is to keep track of the expected next opaque value and
compare it with the one returned by hardware during RX and TPA start
completions. If they miscompare, log it, discard the completion,
schedule a ring reset and move on to the next one.

Fixes: 0958d8b6435d ("net/bnxt: support LRO")
Cc: stable@dpdk.org

Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>

drivers/net/bnxt/bnxt_hwrm.c

@@ -2711,6 +2711,25 @@ void bnxt_free_hwrm_rx_ring(struct bnxt *bp, int queue_index)
 		bp->grp_info[queue_index].cp_fw_ring_id = INVALID_HW_RING_ID;
 }
 
+int bnxt_hwrm_rx_ring_reset(struct bnxt *bp, int queue_index)
+{
+	int rc;
+	struct hwrm_ring_reset_input req = {.req_type = 0 };
+	struct hwrm_ring_reset_output *resp = bp->hwrm_cmd_resp_addr;
+
+	HWRM_PREP(&req, HWRM_RING_RESET, BNXT_USE_CHIMP_MB);
+
+	req.ring_type = HWRM_RING_RESET_INPUT_RING_TYPE_RX_RING_GRP;
+	req.ring_id = rte_cpu_to_le_16(bp->grp_info[queue_index].fw_grp_id);
+	rc = bnxt_hwrm_send_message(bp, &req, sizeof(req), BNXT_USE_CHIMP_MB);
+
+	HWRM_CHECK_RESULT();
+
+	HWRM_UNLOCK();
+
+	return rc;
+}
+
 static int
 bnxt_free_all_hwrm_rings(struct bnxt *bp)
 {

drivers/net/bnxt/bnxt_hwrm.h

@@ -301,4 +301,5 @@ int bnxt_hwrm_cfa_adv_flow_mgmt_qcaps(struct bnxt *bp);
 int bnxt_hwrm_fw_echo_reply(struct bnxt *bp, uint32_t echo_req_data1,
 			    uint32_t echo_req_data2);
 int bnxt_hwrm_poll_ver_get(struct bnxt *bp);
+int bnxt_hwrm_rx_ring_reset(struct bnxt *bp, int queue_index);
 #endif

drivers/net/bnxt/bnxt_rxq.h

@@ -30,6 +30,7 @@ struct bnxt_rx_queue {
 	uint8_t			rx_deferred_start; /* not in global dev start */
 	uint8_t			rx_started; /* RX queue is started */
 	uint8_t			drop_en; /* Drop when rx desc not available. */
+	uint8_t			in_reset; /* Rx ring is scheduled for reset */
 
 	struct bnxt		*bp;
 	int			index;

drivers/net/bnxt/bnxt_rxr.c

@@ -10,6 +10,7 @@
 #include <rte_byteorder.h>
 #include <rte_malloc.h>
 #include <rte_memory.h>
+#include <rte_alarm.h>
 
 #include "bnxt.h"
 #include "bnxt_reps.h"
@@ -17,9 +18,7 @@
 #include "bnxt_rxr.h"
 #include "bnxt_rxq.h"
 #include "hsi_struct_def_dpdk.h"
-#ifdef RTE_LIBRTE_IEEE1588
 #include "bnxt_hwrm.h"
-#endif
 
 #include <bnxt_tf_common.h>
 #include <ulp_mark_mgr.h>
@@ -134,6 +133,51 @@ struct rte_mbuf *bnxt_consume_rx_buf(struct bnxt_rx_ring_info *rxr,
 	return mbuf;
 }
 
+static void bnxt_rx_ring_reset(void *arg)
+{
+	struct bnxt *bp = arg;
+	int i, rc = 0;
+	struct bnxt_rx_queue *rxq;
+
+
+	for (i = 0; i < (int)bp->rx_nr_rings; i++) {
+		struct bnxt_rx_ring_info *rxr;
+
+		rxq = bp->rx_queues[i];
+		if (!rxq || !rxq->in_reset)
+			continue;
+
+		rxr = rxq->rx_ring;
+		/* Disable and flush TPA before resetting the RX ring */
+		if (rxr->tpa_info)
+			bnxt_hwrm_vnic_tpa_cfg(bp, rxq->vnic, false);
+		rc = bnxt_hwrm_rx_ring_reset(bp, i);
+		if (rc) {
+			PMD_DRV_LOG(ERR, "Rx ring%d reset failed\n", i);
+			continue;
+		}
+
+		bnxt_rx_queue_release_mbufs(rxq);
+		rxr->rx_raw_prod = 0;
+		rxr->ag_raw_prod = 0;
+		rxr->rx_next_cons = 0;
+		bnxt_init_one_rx_ring(rxq);
+		bnxt_db_write(&rxr->rx_db, rxr->rx_raw_prod);
+		bnxt_db_write(&rxr->ag_db, rxr->ag_raw_prod);
+		if (rxr->tpa_info)
+			bnxt_hwrm_vnic_tpa_cfg(bp, rxq->vnic, true);
+
+		rxq->in_reset = 0;
+	}
+}
+
+
+static void bnxt_sched_ring_reset(struct bnxt_rx_queue *rxq)
+{
+	rxq->in_reset = 1;
+	rte_eal_alarm_set(1, bnxt_rx_ring_reset, (void *)rxq->bp);
+}
+
 static void bnxt_tpa_get_metadata(struct bnxt *bp,
 				  struct bnxt_tpa_info *tpa_info,
 				  struct rx_tpa_start_cmpl *tpa_start,
@@ -195,6 +239,12 @@ static void bnxt_tpa_start(struct bnxt_rx_queue *rxq,
 
 	data_cons = tpa_start->opaque;
 	tpa_info = &rxr->tpa_info[agg_id];
+	if (unlikely(data_cons != rxr->rx_next_cons)) {
+		PMD_DRV_LOG(ERR, "TPA cons %x, expected cons %x\n",
+			    data_cons, rxr->rx_next_cons);
+		bnxt_sched_ring_reset(rxq);
+		return;
+	}
 
 	mbuf = bnxt_consume_rx_buf(rxr, data_cons);
 
@@ -233,6 +283,9 @@ static void bnxt_tpa_start(struct bnxt_rx_queue *rxq,
 	/* recycle next mbuf */
 	data_cons = RING_NEXT(data_cons);
 	bnxt_reuse_rx_mbuf(rxr, bnxt_consume_rx_buf(rxr, data_cons));
+
+	rxr->rx_next_cons = RING_IDX(rxr->rx_ring_struct,
+				     RING_NEXT(data_cons));
 }
 
 static int bnxt_agg_bufs_valid(struct bnxt_cp_ring_info *cpr,
@@ -330,6 +383,34 @@ static int bnxt_rx_pages(struct bnxt_rx_queue *rxq,
 	return 0;
 }
 
+static int bnxt_discard_rx(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
+			   uint32_t *raw_cons, void *cmp)
+{
+	struct rx_pkt_cmpl *rxcmp = cmp;
+	uint32_t tmp_raw_cons = *raw_cons;
+	uint8_t cmp_type, agg_bufs = 0;
+
+	cmp_type = CMP_TYPE(rxcmp);
+
+	if (cmp_type == CMPL_BASE_TYPE_RX_L2) {
+		agg_bufs = BNXT_RX_L2_AGG_BUFS(rxcmp);
+	} else if (cmp_type == RX_TPA_END_CMPL_TYPE_RX_TPA_END) {
+		struct rx_tpa_end_cmpl *tpa_end = cmp;
+
+		if (BNXT_CHIP_P5(bp))
+			return 0;
+
+		agg_bufs = BNXT_TPA_END_AGG_BUFS(tpa_end);
+	}
+
+	if (agg_bufs) {
+		if (!bnxt_agg_bufs_valid(cpr, agg_bufs, tmp_raw_cons))
+			return -EBUSY;
+	}
+	*raw_cons = tmp_raw_cons;
+	return 0;
+}
+
 static inline struct rte_mbuf *bnxt_tpa_end(
 		struct bnxt_rx_queue *rxq,
 		uint32_t *raw_cp_cons,
@@ -344,6 +425,13 @@ static inline struct rte_mbuf *bnxt_tpa_end(
 	uint8_t payload_offset;
 	struct bnxt_tpa_info *tpa_info;
 
+	if (unlikely(rxq->in_reset)) {
+		PMD_DRV_LOG(ERR, "rxq->in_reset: raw_cp_cons:%d\n",
+			    *raw_cp_cons);
+		bnxt_discard_rx(rxq->bp, cpr, raw_cp_cons, tpa_end);
+		return NULL;
+	}
+
 	if (BNXT_CHIP_P5(rxq->bp)) {
 		struct rx_tpa_v2_end_cmpl *th_tpa_end;
 		struct rx_tpa_v2_end_cmpl_hi *th_tpa_end1;
@@ -841,6 +929,14 @@ static int bnxt_rx_pkt(struct rte_mbuf **rx_pkt,
 	raw_prod = rxr->rx_raw_prod;
 
 	cons = rxcmp->opaque;
+	if (unlikely(cons != rxr->rx_next_cons)) {
+		bnxt_discard_rx(bp, cpr, &tmp_raw_cons, rxcmp);
+		PMD_DRV_LOG(ERR, "RX cons %x != expected cons %x\n",
+			    cons, rxr->rx_next_cons);
+		bnxt_sched_ring_reset(rxq);
+		rc = -EBUSY;
+		goto next_rx;
+	}
 	mbuf = bnxt_consume_rx_buf(rxr, cons);
 	if (mbuf == NULL)
 		return -EBUSY;
@@ -913,6 +1009,7 @@ reuse_rx_mbuf:
 		goto rx;
 	}
 	rxr->rx_raw_prod = raw_prod;
+	rxr->rx_next_cons = RING_IDX(rxr->rx_ring_struct, RING_NEXT(cons));
 
 	if (BNXT_TRUFLOW_EN(bp) && (BNXT_VF_IS_TRUSTED(bp) || BNXT_PF(bp)) &&
 	    vfr_flag) {

drivers/net/bnxt/bnxt_rxr.h

@@ -71,6 +71,7 @@ struct bnxt_rx_ring_info {
 	uint16_t		rx_raw_prod;
 	uint16_t		ag_raw_prod;
 	uint16_t                rx_cons; /* Needed for representor */
+	uint16_t                rx_next_cons;
 	struct bnxt_db_info     rx_db;
 	struct bnxt_db_info     ag_db;