dpaa2-eth: Add PFC support through DCB ops

Add support in dpaa2-eth for PFC (Priority Flow Control)
through the DCB ops.

Instruct the hardware to respond to received PFC frames.
Current firmware doesn't allow us to selectively enable PFC
on the Rx side for some priorities only, so we will react to
all incoming PFC frames (and stop transmitting on the traffic
classes specified in the frame).

Also, 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.

The number of PFC traffic classes available can be queried through
lldptool. Also, which of those traffic classes have PFC enabled is also
controlled through the same dcbnl_rtnl_ops callbacks.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpni.h b/drivers/net/ethernet/freescale/dpaa2/dpni.h
index 8c7ac20bf1a7..e874d8084142 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpni.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpni.h
@@ -514,6 +514,11 @@ int dpni_get_statistics(struct fsl_mc_io	*mc_io,
 #define DPNI_LINK_OPT_ASYM_PAUSE	0x0000000000000008ULL
 
 /**
+ * Enable priority flow control pause frames
+ */
+#define DPNI_LINK_OPT_PFC_PAUSE		0x0000000000000010ULL
+
+/**
  * struct - Structure representing DPNI link configuration
  * @rate: Rate
  * @options: Mask of available options; use 'DPNI_LINK_OPT_<X>' values
@@ -878,6 +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