net: ethernet: mtk_eth_soc: add support for Wireless Ethernet Dispatch (WED)

The Wireless Ethernet Dispatch subsystem on the MT7622 SoC can be
configured to intercept and handle access to the DMA queues and
PCIe interrupts for a MT7615/MT7915 wireless card.
It can manage the internal WDMA (Wireless DMA) controller, which allows
ethernet packets to be passed from the packet switch engine (PSE) to the
wireless card, bypassing the CPU entirely.
This can be used to implement hardware flow offloading from ethernet to
WLAN.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 131 insertions, 0 deletions

diff --git a/include/linux/soc/mediatek/mtk_wed.h b/include/linux/soc/mediatek/mtk_wed.h
new file mode 100644
index 000000000000..7e00cca06709
--- /dev/null
+++ b/include/linux/soc/mediatek/mtk_wed.h
@@ -0,0 +1,131 @@
+#ifndef __MTK_WED_H
+#define __MTK_WED_H
+
+#include <linux/kernel.h>
+#include <linux/rcupdate.h>
+#include <linux/regmap.h>
+#include <linux/pci.h>
+
+#define MTK_WED_TX_QUEUES		2
+
+struct mtk_wed_hw;
+struct mtk_wdma_desc;
+
+struct mtk_wed_ring {
+	struct mtk_wdma_desc *desc;
+	dma_addr_t desc_phys;
+	int size;
+
+	u32 reg_base;
+	void __iomem *wpdma;
+};
+
+struct mtk_wed_device {
+#ifdef CONFIG_NET_MEDIATEK_SOC_WED
+	const struct mtk_wed_ops *ops;
+	struct device *dev;
+	struct mtk_wed_hw *hw;
+	bool init_done, running;
+	int wdma_idx;
+	int irq;
+
+	struct mtk_wed_ring tx_ring[MTK_WED_TX_QUEUES];
+	struct mtk_wed_ring txfree_ring;
+	struct mtk_wed_ring tx_wdma[MTK_WED_TX_QUEUES];
+
+	struct {
+		int size;
+		void **pages;
+		struct mtk_wdma_desc *desc;
+		dma_addr_t desc_phys;
+	} buf_ring;
+
+	/* filled by driver: */
+	struct {
+		struct pci_dev *pci_dev;
+
+		u32 wpdma_phys;
+
+		u16 token_start;
+		unsigned int nbuf;
+
+		u32 (*init_buf)(void *ptr, dma_addr_t phys, int token_id);
+		int (*offload_enable)(struct mtk_wed_device *wed);
+		void (*offload_disable)(struct mtk_wed_device *wed);
+	} wlan;
+#endif
+};
+
+struct mtk_wed_ops {
+	int (*attach)(struct mtk_wed_device *dev);
+	int (*tx_ring_setup)(struct mtk_wed_device *dev, int ring,
+			     void __iomem *regs);
+	int (*txfree_ring_setup)(struct mtk_wed_device *dev,
+				 void __iomem *regs);
+	void (*detach)(struct mtk_wed_device *dev);
+
+	void (*stop)(struct mtk_wed_device *dev);
+	void (*start)(struct mtk_wed_device *dev, u32 irq_mask);
+	void (*reset_dma)(struct mtk_wed_device *dev);
+
+	u32 (*reg_read)(struct mtk_wed_device *dev, u32 reg);
+	void (*reg_write)(struct mtk_wed_device *dev, u32 reg, u32 val);
+
+	u32 (*irq_get)(struct mtk_wed_device *dev, u32 mask);
+	void (*irq_set_mask)(struct mtk_wed_device *dev, u32 mask);
+};
+
+extern const struct mtk_wed_ops __rcu *mtk_soc_wed_ops;
+
+static inline int
+mtk_wed_device_attach(struct mtk_wed_device *dev)
+{
+	int ret = -ENODEV;
+
+#ifdef CONFIG_NET_MEDIATEK_SOC_WED
+	rcu_read_lock();
+	dev->ops = rcu_dereference(mtk_soc_wed_ops);
+	if (dev->ops)
+		ret = dev->ops->attach(dev);
+	else
+		rcu_read_unlock();
+
+	if (ret)
+		dev->ops = NULL;
+#endif
+
+	return ret;
+}
+
+#ifdef CONFIG_NET_MEDIATEK_SOC_WED
+#define mtk_wed_device_active(_dev) !!(_dev)->ops
+#define mtk_wed_device_detach(_dev) (_dev)->ops->detach(_dev)
+#define mtk_wed_device_start(_dev, _mask) (_dev)->ops->start(_dev, _mask)
+#define mtk_wed_device_tx_ring_setup(_dev, _ring, _regs) \
+	(_dev)->ops->tx_ring_setup(_dev, _ring, _regs)
+#define mtk_wed_device_txfree_ring_setup(_dev, _regs) \
+	(_dev)->ops->txfree_ring_setup(_dev, _regs)
+#define mtk_wed_device_reg_read(_dev, _reg) \
+	(_dev)->ops->reg_read(_dev, _reg)
+#define mtk_wed_device_reg_write(_dev, _reg, _val) \
+	(_dev)->ops->reg_write(_dev, _reg, _val)
+#define mtk_wed_device_irq_get(_dev, _mask) \
+	(_dev)->ops->irq_get(_dev, _mask)
+#define mtk_wed_device_irq_set_mask(_dev, _mask) \
+	(_dev)->ops->irq_set_mask(_dev, _mask)
+#else
+static inline bool mtk_wed_device_active(struct mtk_wed_device *dev)
+{
+	return false;
+}
+#define mtk_wed_device_detach(_dev) do {} while (0)
+#define mtk_wed_device_start(_dev, _mask) do {} while (0)
+#define mtk_wed_device_tx_ring_setup(_dev, _ring, _regs) -ENODEV
+#define mtk_wed_device_txfree_ring_setup(_dev, _ring, _regs) -ENODEV
+#define mtk_wed_device_reg_read(_dev, _reg) 0
+#define mtk_wed_device_reg_write(_dev, _reg, _val) do {} while (0)
+#define mtk_wed_device_irq_get(_dev, _mask) 0
+#define mtk_wed_device_irq_set_mask(_dev, _mask) do {} while (0)
+#endif
+
+#endif