bnxt_en: Accumulate all counters.

Now that we have the infrastructure in place, add the new function
bnxt_accumulate_all_stats() to periodically accumulate and check for
counter rollover of all ring stats and port stats.

A chip bug was also discovered that could cause some ring counters to
become 0 during DMA.  Workaround by ignoring zeros on the affected
chips.

Some older frimware will reset port counters during ifdown.  We need
to check for that and free the accumulated port counters during ifdown
to prevent bogus counter overflow detection during ifup.
Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -4051,6 +4051,8 @@ static void bnxt_free_mem(struct bnxt *bp, bool irq_re_init)
 	bnxt_free_ntp_fltrs(bp, irq_re_init);
 	if (irq_re_init) {
 		bnxt_free_ring_stats(bp);
+		if (!(bp->fw_cap & BNXT_FW_CAP_PORT_STATS_NO_RESET))
+			bnxt_free_port_stats(bp);
 		bnxt_free_ring_grps(bp);
 		bnxt_free_vnics(bp);
 		kfree(bp->tx_ring_map);
@@ -7592,6 +7594,88 @@ int bnxt_hwrm_fw_set_time(struct bnxt *bp)
 	return hwrm_send_message(bp, &req, sizeof(req), HWRM_CMD_TIMEOUT);
 }
 
+static void bnxt_add_one_ctr(u64 hw, u64 *sw, u64 mask)
+{
+	u64 sw_tmp;
+
+	sw_tmp = (*sw & ~mask) | hw;
+	if (hw < (*sw & mask))
+		sw_tmp += mask + 1;
+	WRITE_ONCE(*sw, sw_tmp);
+}
+
+static void __bnxt_accumulate_stats(__le64 *hw_stats, u64 *sw_stats, u64 *masks,
+				    int count, bool ignore_zero)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		u64 hw = le64_to_cpu(READ_ONCE(hw_stats[i]));
+
+		if (ignore_zero && !hw)
+			continue;
+
+		if (masks[i] == -1ULL)
+			sw_stats[i] = hw;
+		else
+			bnxt_add_one_ctr(hw, &sw_stats[i], masks[i]);
+	}
+}
+
+static void bnxt_accumulate_stats(struct bnxt_stats_mem *stats)
+{
+	if (!stats->hw_stats)
+		return;
+
+	__bnxt_accumulate_stats(stats->hw_stats, stats->sw_stats,
+				stats->hw_masks, stats->len / 8, false);
+}
+
+static void bnxt_accumulate_all_stats(struct bnxt *bp)
+{
+	struct bnxt_stats_mem *ring0_stats;
+	bool ignore_zero = false;
+	int i;
+
+	/* Chip bug.  Counter intermittently becomes 0. */
+	if (bp->flags & BNXT_FLAG_CHIP_P5)
+		ignore_zero = true;
+
+	for (i = 0; i < bp->cp_nr_rings; i++) {
+		struct bnxt_napi *bnapi = bp->bnapi[i];
+		struct bnxt_cp_ring_info *cpr;
+		struct bnxt_stats_mem *stats;
+
+		cpr = &bnapi->cp_ring;
+		stats = &cpr->stats;
+		if (!i)
+			ring0_stats = stats;
+		__bnxt_accumulate_stats(stats->hw_stats, stats->sw_stats,
+					ring0_stats->hw_masks,
+					ring0_stats->len / 8, ignore_zero);
+	}
+	if (bp->flags & BNXT_FLAG_PORT_STATS) {
+		struct bnxt_stats_mem *stats = &bp->port_stats;
+		__le64 *hw_stats = stats->hw_stats;
+		u64 *sw_stats = stats->sw_stats;
+		u64 *masks = stats->hw_masks;
+		int cnt;
+
+		cnt = sizeof(struct rx_port_stats) / 8;
+		__bnxt_accumulate_stats(hw_stats, sw_stats, masks, cnt, false);
+
+		hw_stats += BNXT_TX_PORT_STATS_BYTE_OFFSET / 8;
+		sw_stats += BNXT_TX_PORT_STATS_BYTE_OFFSET / 8;
+		masks += BNXT_TX_PORT_STATS_BYTE_OFFSET / 8;
+		cnt = sizeof(struct tx_port_stats) / 8;
+		__bnxt_accumulate_stats(hw_stats, sw_stats, masks, cnt, false);
+	}
+	if (bp->flags & BNXT_FLAG_PORT_STATS_EXT) {
+		bnxt_accumulate_stats(&bp->rx_port_stats_ext);
+		bnxt_accumulate_stats(&bp->tx_port_stats_ext);
+	}
+}
+
 static int bnxt_hwrm_port_qstats(struct bnxt *bp, u8 flags)
 {
 	struct bnxt_pf_info *pf = &bp->pf;
@@ -8710,6 +8794,9 @@ static int bnxt_hwrm_phy_qcaps(struct bnxt *bp)
 		if (BNXT_PF(bp))
 			bp->fw_cap |= BNXT_FW_CAP_SHARED_PORT_CFG;
 	}
+	if (resp->flags & PORT_PHY_QCAPS_RESP_FLAGS_CUMULATIVE_COUNTERS_ON_RESET)
+		bp->fw_cap |= BNXT_FW_CAP_PORT_STATS_NO_RESET;
+
 	if (resp->supported_speeds_auto_mode)
 		link_info->support_auto_speeds =
 			le16_to_cpu(resp->supported_speeds_auto_mode);
@@ -10280,8 +10367,7 @@ static void bnxt_timer(struct timer_list *t)
 	if (bp->fw_cap & BNXT_FW_CAP_ERROR_RECOVERY)
 		bnxt_fw_health_check(bp);
 
-	if (bp->link_info.link_up && (bp->flags & BNXT_FLAG_PORT_STATS) &&
-	    bp->stats_coal_ticks) {
+	if (bp->link_info.link_up && bp->stats_coal_ticks) {
 		set_bit(BNXT_PERIODIC_STATS_SP_EVENT, &bp->sp_event);
 		bnxt_queue_sp_work(bp);
 	}
@@ -10569,6 +10655,7 @@ static void bnxt_sp_task(struct work_struct *work)
 	if (test_and_clear_bit(BNXT_PERIODIC_STATS_SP_EVENT, &bp->sp_event)) {
 		bnxt_hwrm_port_qstats(bp, 0);
 		bnxt_hwrm_port_qstats_ext(bp, 0);
+		bnxt_accumulate_all_stats(bp);
 	}
 
 	if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) {

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1769,6 +1769,7 @@ struct bnxt {
 	#define BNXT_FW_CAP_VLAN_RX_STRIP		0x01000000
 	#define BNXT_FW_CAP_VLAN_TX_INSERT		0x02000000
 	#define BNXT_FW_CAP_EXT_HW_STATS_SUPPORTED	0x04000000
+	#define BNXT_FW_CAP_PORT_STATS_NO_RESET		0x10000000
 
 #define BNXT_NEW_RM(bp)		((bp)->fw_cap & BNXT_FW_CAP_NEW_RM)
 	u32			hwrm_spec_code;