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, 49 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
index 0ae85f8adf67..5b010ebfede9 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
@@ -707,3 +707,52 @@ void dwmac5_fpe_configure(void __iomem *ioaddr, u32 num_txq, u32 num_rxq,
 	value |= EFPE;
 	writel(value, ioaddr + MAC_FPE_CTRL_STS);
 }
+
+int dwmac5_fpe_irq_status(void __iomem *ioaddr, struct net_device *dev)
+{
+	u32 value;
+	int status;
+
+	status = FPE_EVENT_UNKNOWN;
+
+	value = readl(ioaddr + MAC_FPE_CTRL_STS);
+
+	if (value & TRSP) {
+		status |= FPE_EVENT_TRSP;
+		netdev_info(dev, "FPE: Respond mPacket is transmitted\n");
+	}
+
+	if (value & TVER) {
+		status |= FPE_EVENT_TVER;
+		netdev_info(dev, "FPE: Verify mPacket is transmitted\n");
+	}
+
+	if (value & RRSP) {
+		status |= FPE_EVENT_RRSP;
+		netdev_info(dev, "FPE: Respond mPacket is received\n");
+	}
+
+	if (value & RVER) {
+		status |= FPE_EVENT_RVER;
+		netdev_info(dev, "FPE: Verify mPacket is received\n");
+	}
+
+	return status;
+}
+
+void dwmac5_fpe_send_mpacket(void __iomem *ioaddr, enum stmmac_mpacket_type type)
+{
+	u32 value;
+
+	value = readl(ioaddr + MAC_FPE_CTRL_STS);
+
+	if (type == MPACKET_VERIFY) {
+		value &= ~SRSP;
+		value |= SVER;
+	} else {
+		value &= ~SVER;
+		value |= SRSP;
+	}
+
+	writel(value, ioaddr + MAC_FPE_CTRL_STS);
+}