openwrt/target/linux/layerscape/patches-5.4/701-net-0201-dpaa2-eth-Enable-Tx-PFC.patch

From 07fb72fb5b3d2faeeb742ae573aa54a4a1eeee12 Mon Sep 17 00:00:00 2001
From: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Date: Tue, 17 Sep 2019 20:36:08 +0300
Subject: [PATCH] dpaa2-eth: Enable Tx PFC

Configure the hardware to generate PFC frames based on Rx congestion
notifications. When a certain number of frames accumulate in the
ingress queues corresponding to a traffic class, priority flow control
frames are generated for that TC.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 49 ++++++++++++++++++++-
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h | 11 +++++
 drivers/net/ethernet/freescale/dpaa2/dpni-cmd.h  | 25 +++++++++++
 drivers/net/ethernet/freescale/dpaa2/dpni.c      | 46 +++++++++++++++++++
 drivers/net/ethernet/freescale/dpaa2/dpni.h      | 56 ++++++++++++++++++++++++
 5 files changed, 186 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -3629,6 +3629,47 @@ static int dpaa2_eth_dcbnl_ieee_getpfc(s
 	return 0;
 }
 
+static inline bool is_prio_enabled(u8 pfc_en, u8 tc)
+{
+	return !!(pfc_en & (1 << tc));
+}
+
+static int set_pfc_cn(struct dpaa2_eth_priv *priv, u8 pfc_en)
+{
+	struct dpni_congestion_notification_cfg cfg = {0};
+	int i, err;
+
+	cfg.notification_mode = DPNI_CONG_OPT_FLOW_CONTROL;
+	cfg.units = DPNI_CONGESTION_UNIT_FRAMES;
+	cfg.message_iova = 0ULL;
+	cfg.message_ctx = 0ULL;
+
+	for (i = 0; i < dpaa2_eth_tc_count(priv); i++) {
+		if (is_prio_enabled(pfc_en, i)) {
+			cfg.threshold_entry = DPAA2_ETH_CN_THRESH_ENTRY(priv);
+			cfg.threshold_exit = DPAA2_ETH_CN_THRESH_EXIT(priv);
+		} else {
+			/* For priorities not set in the pfc_en mask, we leave
+			 * the congestion thresholds at zero, which effectively
+			 * disables generation of PFC frames for them
+			 */
+			cfg.threshold_entry = 0;
+			cfg.threshold_exit = 0;
+		}
+
+		err = dpni_set_congestion_notification(priv->mc_io, 0,
+						       priv->mc_token,
+						       DPNI_QUEUE_RX, i, &cfg);
+		if (err) {
+			netdev_err(priv->net_dev,
+				   "dpni_set_congestion_notification failed\n");
+			return err;
+		}
+	}
+
+	return 0;
+}
+
 static int dpaa2_eth_dcbnl_ieee_setpfc(struct net_device *net_dev,
 				       struct ieee_pfc *pfc)
 {
@@ -3646,7 +3687,8 @@ static int dpaa2_eth_dcbnl_ieee_setpfc(s
 	/* We allow PFC configuration even if it won't have any effect until
 	 * general pause frames are enabled
 	 */
-	if (!dpaa2_eth_rx_pause_enabled(priv->link_state.options))
+	if (!dpaa2_eth_rx_pause_enabled(priv->link_state.options) ||
+	    !dpaa2_eth_tx_pause_enabled(priv->link_state.options))
 		netdev_warn(net_dev, "Pause support must be enabled in order for PFC to work!\n");
 
 	link_cfg.rate = priv->link_state.rate;
@@ -3661,6 +3703,11 @@ static int dpaa2_eth_dcbnl_ieee_setpfc(s
 		return err;
 	}
 
+	/* Configure congestion notifications for the enabled priorities */
+	err = set_pfc_cn(priv, pfc->pfc_en);
+	if (err)
+		return err;
+
 	memcpy(&priv->pfc, pfc, sizeof(priv->pfc));
 
 	return 0;
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
@@ -65,6 +65,17 @@
 #define DPAA2_ETH_CG_TAILDROP_THRESH(priv)				\
 	(1024 * dpaa2_eth_queue_count(priv) / dpaa2_eth_tc_count(priv))
 
+/* Congestion group notification threshold: when this many frames accumulate
+ * on the Rx queues belonging to the same TC, the MAC is instructed to send
+ * PFC frames for that TC.
+ * When number of pending frames drops below exit threshold transmission of
+ * PFC frames is stopped.
+ */
+#define DPAA2_ETH_CN_THRESH_ENTRY(priv) \
+	(DPAA2_ETH_CG_TAILDROP_THRESH(priv) / 2)
+#define DPAA2_ETH_CN_THRESH_EXIT(priv) \
+	(DPAA2_ETH_CN_THRESH_ENTRY(priv) * 3 / 4)
+
 /* Maximum number of buffers that can be acquired/released through a single
  * QBMan command
  */
--- a/drivers/net/ethernet/freescale/dpaa2/dpni-cmd.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpni-cmd.h
@@ -601,4 +601,29 @@ struct dpni_cmd_remove_qos_entry {
 	__le64 mask_iova;
 };
 
+#define DPNI_DEST_TYPE_SHIFT		0
+#define DPNI_DEST_TYPE_SIZE		4
+#define DPNI_CONG_UNITS_SHIFT		4
+#define DPNI_CONG_UNITS_SIZE		2
+
+struct dpni_cmd_set_congestion_notification {
+	/* cmd word 0 */
+	u8 qtype;
+	u8 tc;
+	u8 pad[6];
+	/* cmd word 1 */
+	__le32 dest_id;
+	__le16 notification_mode;
+	u8 dest_priority;
+	/* from LSB: dest_type: 4 units:2 */
+	u8 type_units;
+	/* cmd word 2 */
+	__le64 message_iova;
+	/* cmd word 3 */
+	__le64 message_ctx;
+	/* cmd word 4 */
+	__le32 threshold_entry;
+	__le32 threshold_exit;
+};
+
 #endif /* _FSL_DPNI_CMD_H */
--- a/drivers/net/ethernet/freescale/dpaa2/dpni.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpni.c
@@ -1355,6 +1355,52 @@ int dpni_set_rx_tc_dist(struct fsl_mc_io
 }
 
 /**
+ * dpni_set_congestion_notification() - Set traffic class congestion
+ *					notification configuration
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPNI object
+ * @qtype:	Type of queue - Rx, Tx and Tx confirm types are supported
+ * @tc_id:	Traffic class selection (0-7)
+ * @cfg:	Congestion notification configuration
+ *
+ * Return:	'0' on Success; error code otherwise.
+ */
+int dpni_set_congestion_notification(
+			struct fsl_mc_io *mc_io,
+			u32 cmd_flags,
+			u16 token,
+			enum dpni_queue_type qtype,
+			u8 tc_id,
+			const struct dpni_congestion_notification_cfg *cfg)
+{
+	struct dpni_cmd_set_congestion_notification *cmd_params;
+	struct fsl_mc_command cmd = { 0 };
+
+	/* prepare command */
+	cmd.header =
+		mc_encode_cmd_header(DPNI_CMDID_SET_CONGESTION_NOTIFICATION,
+				     cmd_flags,
+				     token);
+	cmd_params = (struct dpni_cmd_set_congestion_notification *)cmd.params;
+	cmd_params->qtype = qtype;
+	cmd_params->tc = tc_id;
+	cmd_params->dest_id = cpu_to_le32(cfg->dest_cfg.dest_id);
+	cmd_params->notification_mode = cpu_to_le16(cfg->notification_mode);
+	cmd_params->dest_priority = cfg->dest_cfg.priority;
+	dpni_set_field(cmd_params->type_units, DEST_TYPE,
+		       cfg->dest_cfg.dest_type);
+	dpni_set_field(cmd_params->type_units, CONG_UNITS, cfg->units);
+	cmd_params->message_iova = cpu_to_le64(cfg->message_iova);
+	cmd_params->message_ctx = cpu_to_le64(cfg->message_ctx);
+	cmd_params->threshold_entry = cpu_to_le32(cfg->threshold_entry);
+	cmd_params->threshold_exit = cpu_to_le32(cfg->threshold_exit);
+
+	/* send command to mc*/
+	return mc_send_command(mc_io, &cmd);
+}
+
+/**
  * dpni_set_queue() - Set queue parameters
  * @mc_io:	Pointer to MC portal's I/O object
  * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
--- a/drivers/net/ethernet/freescale/dpaa2/dpni.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpni.h
@@ -883,6 +883,62 @@ enum dpni_congestion_point {
 };
 
 /**
+ * struct dpni_dest_cfg - Structure representing DPNI destination parameters
+ * @dest_type:	Destination type
+ * @dest_id:	Either DPIO ID or DPCON ID, depending on the destination type
+ * @priority:	Priority selection within the DPIO or DPCON channel; valid
+ *		values are 0-1 or 0-7, depending on the number of priorities
+ *		in that channel; not relevant for 'DPNI_DEST_NONE' option
+ */
+struct dpni_dest_cfg {
+	enum dpni_dest dest_type;
+	int dest_id;
+	u8 priority;
+};
+
+/* DPNI congestion options */
+
+/**
+ * This congestion will trigger flow control or priority flow control.
+ * This will have effect only if flow control is enabled with
+ * dpni_set_link_cfg().
+ */
+#define DPNI_CONG_OPT_FLOW_CONTROL		0x00000040
+
+/**
+ * struct dpni_congestion_notification_cfg - congestion notification
+ *					configuration
+ * @units: Units type
+ * @threshold_entry: Above this threshold we enter a congestion state.
+ *		set it to '0' to disable it
+ * @threshold_exit: Below this threshold we exit the congestion state.
+ * @message_ctx: The context that will be part of the CSCN message
+ * @message_iova: I/O virtual address (must be in DMA-able memory),
+ *		must be 16B aligned; valid only if 'DPNI_CONG_OPT_WRITE_MEM_<X>'
+ *		is contained in 'options'
+ * @dest_cfg: CSCN can be send to either DPIO or DPCON WQ channel
+ * @notification_mode: Mask of available options; use 'DPNI_CONG_OPT_<X>' values
+ */
+
+struct dpni_congestion_notification_cfg {
+	enum dpni_congestion_unit units;
+	u32 threshold_entry;
+	u32 threshold_exit;
+	u64 message_ctx;
+	u64 message_iova;
+	struct dpni_dest_cfg dest_cfg;
+	u16 notification_mode;
+};
+
+int dpni_set_congestion_notification(
+			struct fsl_mc_io *mc_io,
+			u32 cmd_flags,
+			u16 token,
+			enum dpni_queue_type qtype,
+			u8 tc_id,
+			const struct dpni_congestion_notification_cfg *cfg);
+
+/**
  * struct dpni_taildrop - Structure representing the taildrop
  * @enable:	Indicates whether the taildrop is active or not.
  * @units:	Indicates the unit of THRESHOLD. Queue taildrop only supports