net: stmmac: support FPE link partner hand-shaking procedure

In order to discover whether remote station supports frame preemption,
local station sends verify mPacket and expects response mPacket in
return from the remote station.

So, we add the functions to send and handle event when verify mPacket
and response mPacket are exchanged between the networked stations.

The mechanism to handle different FPE states between local and remote
station (link partner) is implemented using workqueue which starts a
task each time there is some sign of verify & response mPacket exchange
as check in FPE IRQ event. The task retries couple of times to try to
spot the states that both stations are ready to enter FPE ON. This allows
different end points to enable FPE at different time and verify-response
mPacket can happen asynchronously. Ultimately, the task will only turn
FPE ON when local station have both exchange response in both directions.

Thanks to Voon Weifeng for implementing the core functions for detecting
FPE events and send mPacket and phylink related change.

Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Co-developed-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Co-developed-by: Tan Tee Min <tee.min.tan@intel.com>
Signed-off-by: Tan Tee Min <tee.min.tan@intel.com>
Co-developed-by: Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com>
Signed-off-by: Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 5134e802f39a..febdb43d27e5 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -144,6 +144,32 @@ struct stmmac_txq_cfg {
 	int tbs_en;
 };
 
+/* FPE link state */
+enum stmmac_fpe_state {
+	FPE_STATE_OFF = 0,
+	FPE_STATE_CAPABLE = 1,
+	FPE_STATE_ENTERING_ON = 2,
+	FPE_STATE_ON = 3,
+};
+
+/* FPE link-partner hand-shaking mPacket type */
+enum stmmac_mpacket_type {
+	MPACKET_VERIFY = 0,
+	MPACKET_RESPONSE = 1,
+};
+
+enum stmmac_fpe_task_state_t {
+	__FPE_REMOVING,
+	__FPE_TASK_SCHED,
+};
+
+struct stmmac_fpe_cfg {
+	bool enable;				/* FPE enable */
+	bool hs_enable;				/* FPE handshake enable */
+	enum stmmac_fpe_state lp_fpe_state;	/* Link Partner FPE state */
+	enum stmmac_fpe_state lo_fpe_state;	/* Local station FPE state */
+};
+
 struct plat_stmmacenet_data {
 	int bus_id;
 	int phy_addr;
@@ -155,6 +181,7 @@ struct plat_stmmacenet_data {
 	struct device_node *mdio_node;
 	struct stmmac_dma_cfg *dma_cfg;
 	struct stmmac_est *est;
+	struct stmmac_fpe_cfg *fpe_cfg;
 	int clk_csr;
 	int has_gmac;
 	int enh_desc;