eth: fbnic: add support for TTI HW stats

Add coverage for the TX Extension (TEI) Interface (TTI) stats. We are
tracking packets and control message drops because of credit exhaustion
on the TX interface.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: NipaLocal <nipa@local>

Author: Mohsin Bashir

Documentation/networking/device_drivers/ethernet/meta/fbnic.rst

@@ -38,6 +38,13 @@ TX MAC Interface
  - ``ptp_good_ts``: packets successfully routed to MAC with PTP request bit set
  - ``ptp_bad_ts``: packets destined for MAC with PTP request bit set but aborted because of some error (e.g., DMA read error)
 
+TX Extension (TEI) Interface (TTI)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+ - ``tti_cm_drop``: control messages dropped at the TX Extension (TEI) Interface because of credit starvation
+ - ``tti_frame_drop``: packets dropped at the TX Extension (TEI) Interface because of credit starvation
+ - ``tti_tbi_drop``: packets dropped at the TX BMC Interface (TBI) because of credit starvation
+
 RXB (RX Buffer) Enqueue
 ~~~~~~~~~~~~~~~~~~~~~~~
 

drivers/net/ethernet/meta/fbnic/fbnic_csr.h

@@ -397,6 +397,15 @@ enum {
 #define FBNIC_TCE_DROP_CTRL_TTI_FRM_DROP_EN	CSR_BIT(1)
 #define FBNIC_TCE_DROP_CTRL_TTI_TBI_DROP_EN	CSR_BIT(2)
 
+#define FBNIC_TCE_TTI_CM_DROP_PKTS	0x0403e		/* 0x100f8 */
+#define FBNIC_TCE_TTI_CM_DROP_BYTE_L	0x0403f		/* 0x100fc */
+#define FBNIC_TCE_TTI_CM_DROP_BYTE_H	0x04040		/* 0x10100 */
+#define FBNIC_TCE_TTI_FRAME_DROP_PKTS	0x04041		/* 0x10104 */
+#define FBNIC_TCE_TTI_FRAME_DROP_BYTE_L	0x04042		/* 0x10108 */
+#define FBNIC_TCE_TTI_FRAME_DROP_BYTE_H	0x04043		/* 0x1010c */
+#define FBNIC_TCE_TBI_DROP_PKTS		0x04044		/* 0x10110 */
+#define FBNIC_TCE_TBI_DROP_BYTE_L	0x04045		/* 0x10114 */
+
 #define FBNIC_TCE_TCAM_IDX2DEST_MAP	0x0404A		/* 0x10128 */
 #define FBNIC_TCE_TCAM_IDX2DEST_MAP_DEST_ID_0	CSR_GENMASK(3, 0)
 enum {

drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c

@@ -27,6 +27,14 @@ struct fbnic_stat {
 	FBNIC_STAT_FIELDS(fbnic_hw_stats, name, stat)
 
 static const struct fbnic_stat fbnic_gstrings_hw_stats[] = {
+	/* TTI */
+	FBNIC_HW_STAT("tti_cm_drop_frames", tti.cm_drop.frames),
+	FBNIC_HW_STAT("tti_cm_drop_bytes", tti.cm_drop.bytes),
+	FBNIC_HW_STAT("tti_frame_drop_frames", tti.frame_drop.frames),
+	FBNIC_HW_STAT("tti_frame_drop_bytes", tti.frame_drop.bytes),
+	FBNIC_HW_STAT("tti_tbi_drop_frames", tti.tbi_drop.frames),
+	FBNIC_HW_STAT("tti_tbi_drop_bytes", tti.tbi_drop.bytes),
+
 	/* TMI */
 	FBNIC_HW_STAT("ptp_illegal_req", tmi.ptp_illegal_req),
 	FBNIC_HW_STAT("ptp_good_ts", tmi.ptp_good_ts),

drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c

@@ -101,6 +101,69 @@ static void fbnic_get_tmi_stats(struct fbnic_dev *fbd,
 	fbnic_hw_stat_rd64(fbd, FBNIC_TMI_DROP_BYTE_L, 1, &tmi->drop.bytes);
 }
 
+static void fbnic_reset_tti_stats(struct fbnic_dev *fbd,
+				  struct fbnic_tti_stats *tti)
+{
+	fbnic_hw_stat_rst32(fbd,
+			    FBNIC_TCE_TTI_CM_DROP_PKTS,
+			    &tti->cm_drop.frames);
+	fbnic_hw_stat_rst64(fbd,
+			    FBNIC_TCE_TTI_CM_DROP_BYTE_L,
+			    1,
+			    &tti->cm_drop.bytes);
+
+	fbnic_hw_stat_rst32(fbd,
+			    FBNIC_TCE_TTI_FRAME_DROP_PKTS,
+			    &tti->frame_drop.frames);
+	fbnic_hw_stat_rst64(fbd,
+			    FBNIC_TCE_TTI_FRAME_DROP_BYTE_L,
+			    1,
+			    &tti->frame_drop.bytes);
+
+	fbnic_hw_stat_rst32(fbd,
+			    FBNIC_TCE_TBI_DROP_PKTS,
+			    &tti->tbi_drop.frames);
+	fbnic_hw_stat_rst64(fbd,
+			    FBNIC_TCE_TBI_DROP_BYTE_L,
+			    1,
+			    &tti->tbi_drop.bytes);
+}
+
+static void fbnic_get_tti_stats32(struct fbnic_dev *fbd,
+				  struct fbnic_tti_stats *tti)
+{
+	fbnic_hw_stat_rd32(fbd,
+			   FBNIC_TCE_TTI_CM_DROP_PKTS,
+			   &tti->cm_drop.frames);
+
+	fbnic_hw_stat_rd32(fbd,
+			   FBNIC_TCE_TTI_FRAME_DROP_PKTS,
+			   &tti->frame_drop.frames);
+
+	fbnic_hw_stat_rd32(fbd,
+			   FBNIC_TCE_TBI_DROP_PKTS,
+			   &tti->tbi_drop.frames);
+}
+
+static void fbnic_get_tti_stats(struct fbnic_dev *fbd,
+				struct fbnic_tti_stats *tti)
+{
+	fbnic_hw_stat_rd64(fbd,
+			   FBNIC_TCE_TTI_CM_DROP_BYTE_L,
+			   1,
+			   &tti->cm_drop.bytes);
+
+	fbnic_hw_stat_rd64(fbd,
+			   FBNIC_TCE_TTI_FRAME_DROP_BYTE_L,
+			   1,
+			   &tti->frame_drop.bytes);
+
+	fbnic_hw_stat_rd64(fbd,
+			   FBNIC_TCE_TBI_DROP_BYTE_L,
+			   1,
+			   &tti->tbi_drop.bytes);
+}
+
 static void fbnic_reset_rpc_stats(struct fbnic_dev *fbd,
 				  struct fbnic_rpc_stats *rpc)
 {
@@ -451,6 +514,7 @@ void fbnic_reset_hw_stats(struct fbnic_dev *fbd)
 {
 	spin_lock(&fbd->hw_stats_lock);
 	fbnic_reset_tmi_stats(fbd, &fbd->hw_stats.tmi);
+	fbnic_reset_tti_stats(fbd, &fbd->hw_stats.tti);
 	fbnic_reset_rpc_stats(fbd, &fbd->hw_stats.rpc);
 	fbnic_reset_rxb_stats(fbd, &fbd->hw_stats.rxb);
 	fbnic_reset_hw_rxq_stats(fbd, fbd->hw_stats.hw_q);
@@ -461,6 +525,7 @@ void fbnic_reset_hw_stats(struct fbnic_dev *fbd)
 static void __fbnic_get_hw_stats32(struct fbnic_dev *fbd)
 {
 	fbnic_get_tmi_stats32(fbd, &fbd->hw_stats.tmi);
+	fbnic_get_tti_stats32(fbd, &fbd->hw_stats.tti);
 	fbnic_get_rpc_stats32(fbd, &fbd->hw_stats.rpc);
 	fbnic_get_rxb_stats32(fbd, &fbd->hw_stats.rxb);
 	fbnic_get_hw_rxq_stats32(fbd, fbd->hw_stats.hw_q);
@@ -479,6 +544,7 @@ void fbnic_get_hw_stats(struct fbnic_dev *fbd)
 	__fbnic_get_hw_stats32(fbd);
 
 	fbnic_get_tmi_stats(fbd, &fbd->hw_stats.tmi);
+	fbnic_get_tti_stats(fbd, &fbd->hw_stats.tti);
 	fbnic_get_rxb_stats(fbd, &fbd->hw_stats.rxb);
 	fbnic_get_pcie_stats_asic64(fbd, &fbd->hw_stats.pcie);
 	spin_unlock(&fbd->hw_stats_lock);

drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.h

@@ -47,6 +47,10 @@ struct fbnic_tmi_stats {
 	struct fbnic_stat_counter ptp_illegal_req, ptp_good_ts, ptp_bad_ts;
 };
 
+struct fbnic_tti_stats {
+	struct fbnic_hw_stat cm_drop, frame_drop, tbi_drop;
+};
+
 struct fbnic_rpc_stats {
 	struct fbnic_stat_counter unkn_etype, unkn_ext_hdr;
 	struct fbnic_stat_counter ipv4_frag, ipv6_frag, ipv4_esp, ipv6_esp;
@@ -94,6 +98,7 @@ struct fbnic_pcie_stats {
 struct fbnic_hw_stats {
 	struct fbnic_mac_stats mac;
 	struct fbnic_tmi_stats tmi;
+	struct fbnic_tti_stats tti;
 	struct fbnic_rpc_stats rpc;
 	struct fbnic_rxb_stats rxb;
 	struct fbnic_hw_q_stats hw_q[FBNIC_MAX_QUEUES];

drivers/net/ethernet/meta/fbnic/fbnic_netdev.c

@@ -424,7 +424,10 @@ static void fbnic_get_stats64(struct net_device *dev,
 	stats64->tx_dropped = tx_dropped;
 
 	/* Record drops from Tx HW Datapath */
-	tx_dropped += fbd->hw_stats.tmi.drop.frames.value;
+	tx_dropped += fbd->hw_stats.tmi.drop.frames.value +
+		      fbd->hw_stats.tti.frame_drop.frames.value +
+		      fbd->hw_stats.tti.tbi_drop.frames.value +
+		      fbd->hw_stats.tmi.drop.frames.value;
 
 	for (i = 0; i < fbn->num_tx_queues; i++) {
 		struct fbnic_ring *txr = fbn->tx[i];