net: ethernet: mtk_eth_soc: add dma checks to mtk_hw_reset_check

Introduce mtk_hw_check_dma_hang routine to monitor possible dma hangs.

Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Tested-by: Daniel Golle <daniel@makrotopia.org>
Co-developed-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 773e2b9e9122..5d398595ead0 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -51,6 +51,7 @@ static const struct mtk_reg_map mtk_reg_map = {
 		.delay_irq	= 0x0a0c,
 		.irq_status	= 0x0a20,
 		.irq_mask	= 0x0a28,
+		.adma_rx_dbg0	= 0x0a38,
 		.int_grp	= 0x0a50,
 	},
 	.qdma = {
@@ -82,6 +83,8 @@ static const struct mtk_reg_map mtk_reg_map = {
 		[0]		= 0x2800,
 		[1]		= 0x2c00,
 	},
+	.pse_iq_sta		= 0x0110,
+	.pse_oq_sta		= 0x0118,
 };
 
 static const struct mtk_reg_map mt7628_reg_map = {
@@ -112,6 +115,7 @@ static const struct mtk_reg_map mt7986_reg_map = {
 		.delay_irq	= 0x620c,
 		.irq_status	= 0x6220,
 		.irq_mask	= 0x6228,
+		.adma_rx_dbg0	= 0x6238,
 		.int_grp	= 0x6250,
 	},
 	.qdma = {
@@ -143,6 +147,8 @@ static const struct mtk_reg_map mt7986_reg_map = {
 		[0]		= 0x4800,
 		[1]		= 0x4c00,
 	},
+	.pse_iq_sta		= 0x0180,
+	.pse_oq_sta		= 0x01a0,
 };
 
 /* strings used by ethtool */
@@ -3600,6 +3606,102 @@ static void mtk_hw_warm_reset(struct mtk_eth *eth)
 			val, rst_mask);
 }
 
+static bool mtk_hw_check_dma_hang(struct mtk_eth *eth)
+{
+	const struct mtk_reg_map *reg_map = eth->soc->reg_map;
+	bool gmac1_tx, gmac2_tx, gdm1_tx, gdm2_tx;
+	bool oq_hang, cdm1_busy, adma_busy;
+	bool wtx_busy, cdm_full, oq_free;
+	u32 wdidx, val, gdm1_fc, gdm2_fc;
+	bool qfsm_hang, qfwd_hang;
+	bool ret = false;
+
+	if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628))
+		return false;
+
+	/* WDMA sanity checks */
+	wdidx = mtk_r32(eth, reg_map->wdma_base[0] + 0xc);
+
+	val = mtk_r32(eth, reg_map->wdma_base[0] + 0x204);
+	wtx_busy = FIELD_GET(MTK_TX_DMA_BUSY, val);
+
+	val = mtk_r32(eth, reg_map->wdma_base[0] + 0x230);
+	cdm_full = !FIELD_GET(MTK_CDM_TXFIFO_RDY, val);
+
+	oq_free  = (!(mtk_r32(eth, reg_map->pse_oq_sta) & GENMASK(24, 16)) &&
+		    !(mtk_r32(eth, reg_map->pse_oq_sta + 0x4) & GENMASK(8, 0)) &&
+		    !(mtk_r32(eth, reg_map->pse_oq_sta + 0x10) & GENMASK(24, 16)));
+
+	if (wdidx == eth->reset.wdidx && wtx_busy && cdm_full && oq_free) {
+		if (++eth->reset.wdma_hang_count > 2) {
+			eth->reset.wdma_hang_count = 0;
+			ret = true;
+		}
+		goto out;
+	}
+
+	/* QDMA sanity checks */
+	qfsm_hang = !!mtk_r32(eth, reg_map->qdma.qtx_cfg + 0x234);
+	qfwd_hang = !mtk_r32(eth, reg_map->qdma.qtx_cfg + 0x308);
+
+	gdm1_tx = FIELD_GET(GENMASK(31, 16), mtk_r32(eth, MTK_FE_GDM1_FSM)) > 0;
+	gdm2_tx = FIELD_GET(GENMASK(31, 16), mtk_r32(eth, MTK_FE_GDM2_FSM)) > 0;
+	gmac1_tx = FIELD_GET(GENMASK(31, 24), mtk_r32(eth, MTK_MAC_FSM(0))) != 1;
+	gmac2_tx = FIELD_GET(GENMASK(31, 24), mtk_r32(eth, MTK_MAC_FSM(1))) != 1;
+	gdm1_fc = mtk_r32(eth, reg_map->gdm1_cnt + 0x24);
+	gdm2_fc = mtk_r32(eth, reg_map->gdm1_cnt + 0x64);
+
+	if (qfsm_hang && qfwd_hang &&
+	    ((gdm1_tx && gmac1_tx && gdm1_fc < 1) ||
+	     (gdm2_tx && gmac2_tx && gdm2_fc < 1))) {
+		if (++eth->reset.qdma_hang_count > 2) {
+			eth->reset.qdma_hang_count = 0;
+			ret = true;
+		}
+		goto out;
+	}
+
+	/* ADMA sanity checks */
+	oq_hang = !!(mtk_r32(eth, reg_map->pse_oq_sta) & GENMASK(8, 0));
+	cdm1_busy = !!(mtk_r32(eth, MTK_FE_CDM1_FSM) & GENMASK(31, 16));
+	adma_busy = !(mtk_r32(eth, reg_map->pdma.adma_rx_dbg0) & GENMASK(4, 0)) &&
+		    !(mtk_r32(eth, reg_map->pdma.adma_rx_dbg0) & BIT(6));
+
+	if (oq_hang && cdm1_busy && adma_busy) {
+		if (++eth->reset.adma_hang_count > 2) {
+			eth->reset.adma_hang_count = 0;
+			ret = true;
+		}
+		goto out;
+	}
+
+	eth->reset.wdma_hang_count = 0;
+	eth->reset.qdma_hang_count = 0;
+	eth->reset.adma_hang_count = 0;
+out:
+	eth->reset.wdidx = wdidx;
+
+	return ret;
+}
+
+static void mtk_hw_reset_monitor_work(struct work_struct *work)
+{
+	struct delayed_work *del_work = to_delayed_work(work);
+	struct mtk_eth *eth = container_of(del_work, struct mtk_eth,
+					   reset.monitor_work);
+
+	if (test_bit(MTK_RESETTING, &eth->state))
+		goto out;
+
+	/* DMA stuck checks */
+	if (mtk_hw_check_dma_hang(eth))
+		schedule_work(&eth->pending_work);
+
+out:
+	schedule_delayed_work(&eth->reset.monitor_work,
+			      MTK_DMA_MONITOR_TIMEOUT);
+}
+
 static int mtk_hw_init(struct mtk_eth *eth, bool reset)
 {
 	u32 dma_mask = ETHSYS_DMA_AG_MAP_PDMA | ETHSYS_DMA_AG_MAP_QDMA |
@@ -3949,6 +4051,7 @@ static int mtk_cleanup(struct mtk_eth *eth)
 	mtk_unreg_dev(eth);
 	mtk_free_dev(eth);
 	cancel_work_sync(&eth->pending_work);
+	cancel_delayed_work_sync(&eth->reset.monitor_work);
 
 	return 0;
 }
@@ -4403,6 +4506,7 @@ static int mtk_probe(struct platform_device *pdev)
 
 	eth->rx_dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
 	INIT_WORK(&eth->rx_dim.work, mtk_dim_rx);
+	INIT_DELAYED_WORK(&eth->reset.monitor_work, mtk_hw_reset_monitor_work);
 
 	eth->tx_dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
 	INIT_WORK(&eth->tx_dim.work, mtk_dim_tx);
@@ -4605,6 +4709,8 @@ static int mtk_probe(struct platform_device *pdev)
 	netif_napi_add(&eth->dummy_dev, &eth->rx_napi, mtk_napi_rx);
 
 	platform_set_drvdata(pdev, eth);
+	schedule_delayed_work(&eth->reset.monitor_work,
+			      MTK_DMA_MONITOR_TIMEOUT);
 
 	return 0;