From 07fb72fb5b3d2faeeb742ae573aa54a4a1eeee12 Mon Sep 17 00:00:00 2001 From: Ioana Radulescu 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 --- 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_' + * 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_' 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