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From:   <stefanc@marvell.com>
To:     <netdev@vger.kernel.org>
CC:     <thomas.petazzoni@bootlin.com>, <davem@davemloft.net>,
        <nadavh@marvell.com>, <ymarkman@marvell.com>,
        <linux-kernel@vger.kernel.org>, <stefanc@marvell.com>,
        <kuba@kernel.org>, <linux@armlinux.org.uk>, <mw@semihalf.com>,
        <andrew@lunn.ch>, <rmk+kernel@armlinux.org.uk>,
        <atenart@kernel.org>, <devicetree@vger.kernel.org>,
        <robh+dt@kernel.org>, <sebastian.hesselbarth@gmail.com>,
        <gregory.clement@bootlin.com>,
        <linux-arm-kernel@lists.infradead.org>
Subject: [PATCH v12 net-next 09/15] net: mvpp2: enable global flow control
Date:   Wed, 10 Feb 2021 11:48:14 +0200
Message-ID: <1612950500-9682-10-git-send-email-stefanc@marvell.com>
In-Reply-To: <1612950500-9682-1-git-send-email-stefanc@marvell.com>
References: <1612950500-9682-1-git-send-email-stefanc@marvell.com>
MIME-Version: 1.0
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From: Stefan Chulski <stefanc@marvell.com>

This patch enables global flow control in FW and in the phylink validate mask.

Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Acked-by: Marcin Wojtas <mw@semihalf.com>
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2.h      | 11 +++++--
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 30 +++++++++++++++++++-
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index d2cc513c..8945fb9 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -763,9 +763,11 @@
 		((kb) * 1024 - MVPP2_TX_FIFO_THRESHOLD_MIN)
 
 /* MSS Flow control */
-#define FC_QUANTA		0xFFFF
-#define FC_CLK_DIVIDER		100
-#define MSS_THRESHOLD_STOP	768
+#define MSS_FC_COM_REG			0
+#define FLOW_CONTROL_ENABLE_BIT		BIT(0)
+#define FC_QUANTA			0xFFFF
+#define FC_CLK_DIVIDER			100
+#define MSS_THRESHOLD_STOP		768
 
 /* RX buffer constants */
 #define MVPP2_SKB_SHINFO_SIZE \
@@ -1017,6 +1019,9 @@ struct mvpp2 {
 
 	/* page_pool allocator */
 	struct page_pool *page_pool[MVPP2_PORT_MAX_RXQ];
+
+	/* Global TX Flow Control config */
+	bool global_tx_fc;
 };
 
 struct mvpp2_pcpu_stats {
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 8b4073c..027101b 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -91,6 +91,16 @@ static inline u32 mvpp2_cpu_to_thread(struct mvpp2 *priv, int cpu)
 	return cpu % priv->nthreads;
 }
 
+static void mvpp2_cm3_write(struct mvpp2 *priv, u32 offset, u32 data)
+{
+	writel(data, priv->cm3_base + offset);
+}
+
+static u32 mvpp2_cm3_read(struct mvpp2 *priv, u32 offset)
+{
+	return readl(priv->cm3_base + offset);
+}
+
 static struct page_pool *
 mvpp2_create_page_pool(struct device *dev, int num, int len,
 		       enum dma_data_direction dma_dir)
@@ -5950,6 +5960,11 @@ static void mvpp2_phylink_validate(struct phylink_config *config,
 	phylink_set(mask, Autoneg);
 	phylink_set_port_modes(mask);
 
+	if (port->priv->global_tx_fc) {
+		phylink_set(mask, Pause);
+		phylink_set(mask, Asym_Pause);
+	}
+
 	switch (state->interface) {
 	case PHY_INTERFACE_MODE_10GBASER:
 	case PHY_INTERFACE_MODE_XAUI:
@@ -6951,7 +6966,7 @@ static int mvpp2_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *base;
 	int i, shared;
-	int err;
+	int err, val;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -7003,6 +7018,10 @@ static int mvpp2_probe(struct platform_device *pdev)
 		err = mvpp2_get_sram(pdev, priv);
 		if (err)
 			dev_warn(&pdev->dev, "Fail to alloc CM3 SRAM\n");
+
+		/* Enable global Flow Control only if handler to SRAM not NULL */
+		if (priv->cm3_base)
+			priv->global_tx_fc = true;
 	}
 
 	if (priv->hw_version != MVPP21 && dev_of_node(&pdev->dev)) {
@@ -7168,6 +7187,15 @@ static int mvpp2_probe(struct platform_device *pdev)
 		goto err_port_probe;
 	}
 
+	/* Enable global flow control. In this stage global
+	 * flow control enabled, but still disabled per port.
+	 */
+	if (priv->global_tx_fc && priv->hw_version != MVPP21) {
+		val = mvpp2_cm3_read(priv, MSS_FC_COM_REG);
+		val |= FLOW_CONTROL_ENABLE_BIT;
+		mvpp2_cm3_write(priv, MSS_FC_COM_REG, val);
+	}
+
 	mvpp2_dbgfs_init(priv, pdev->name);
 
 	platform_set_drvdata(pdev, priv);
-- 
1.9.1