[PATCH net-next v4 08/12] net: dsa: rzn1-a5psw: add FDB support

["Clément Léger" <clement.leger@bootlin.com>]

This commits add forwarding database support to the driver. It
implements fdb_add(), fdb_del() and fdb_dump().

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
---
 drivers/net/dsa/rzn1_a5psw.c | 169 +++++++++++++++++++++++++++++++++++
 drivers/net/dsa/rzn1_a5psw.h |  17 ++++
 2 files changed, 186 insertions(+)

diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
index 46ba25672593..ef9d8ef961b5 100644
--- a/drivers/net/dsa/rzn1_a5psw.c
+++ b/drivers/net/dsa/rzn1_a5psw.c
@@ -380,6 +380,172 @@ static void a5psw_port_fast_age(struct dsa_switch *ds, int port)
 	a5psw_port_fdb_flush(a5psw, port);
 }
 
+static int a5psw_lk_execute_lookup(struct a5psw *a5psw, union lk_data *lk_data,
+				   u16 *entry)
+{
+	u32 ctrl;
+	int ret;
+
+	a5psw_reg_writel(a5psw, A5PSW_LK_DATA_LO, lk_data->lo);
+	a5psw_reg_writel(a5psw, A5PSW_LK_DATA_HI, lk_data->hi);
+
+	ctrl = A5PSW_LK_ADDR_CTRL_LOOKUP;
+	ret = a5psw_lk_execute_ctrl(a5psw, &ctrl);
+	if (ret)
+		return ret;
+
+	*entry = ctrl & A5PSW_LK_ADDR_CTRL_ADDRESS;
+
+	return 0;
+}
+
+static int a5psw_port_fdb_add(struct dsa_switch *ds, int port,
+			      const unsigned char *addr, u16 vid,
+			      struct dsa_db db)
+{
+	struct a5psw *a5psw = ds->priv;
+	union lk_data lk_data = {0};
+	bool inc_learncount = false;
+	int ret = 0;
+	u16 entry;
+	u32 reg;
+
+	ether_addr_copy(lk_data.entry.mac, addr);
+	lk_data.entry.port_mask = BIT(port);
+
+	spin_lock(&a5psw->lk_lock);
+
+	/* Set the value to be written in the lookup table */
+	ret = a5psw_lk_execute_lookup(a5psw, &lk_data, &entry);
+	if (ret)
+		goto lk_unlock;
+
+	lk_data.hi = a5psw_reg_readl(a5psw, A5PSW_LK_DATA_HI);
+	if (!lk_data.entry.valid) {
+		inc_learncount = true;
+		/* port_mask set to 0x1f when entry is not valid, clear it */
+		lk_data.entry.port_mask = 0;
+		lk_data.entry.prio = 0;
+	}
+
+	lk_data.entry.port_mask |= BIT(port);
+	lk_data.entry.is_static = 1;
+	lk_data.entry.valid = 1;
+
+	a5psw_reg_writel(a5psw, A5PSW_LK_DATA_HI, lk_data.hi);
+
+	reg = A5PSW_LK_ADDR_CTRL_WRITE | entry;
+	ret = a5psw_lk_execute_ctrl(a5psw, &reg);
+	if (ret)
+		goto lk_unlock;
+
+	if (inc_learncount) {
+		reg = A5PSW_LK_LEARNCOUNT_MODE_INC;
+		a5psw_reg_writel(a5psw, A5PSW_LK_LEARNCOUNT, reg);
+	}
+
+lk_unlock:
+	spin_unlock(&a5psw->lk_lock);
+
+	return ret;
+}
+
+static int a5psw_port_fdb_del(struct dsa_switch *ds, int port,
+			      const unsigned char *addr, u16 vid,
+			      struct dsa_db db)
+{
+	struct a5psw *a5psw = ds->priv;
+	union lk_data lk_data = {0};
+	bool clear = false;
+	u16 entry;
+	u32 reg;
+	int ret;
+
+	ether_addr_copy(lk_data.entry.mac, addr);
+
+	spin_lock(&a5psw->lk_lock);
+
+	ret = a5psw_lk_execute_lookup(a5psw, &lk_data, &entry);
+	if (ret)
+		goto lk_unlock;
+
+	lk_data.hi = a5psw_reg_readl(a5psw, A5PSW_LK_DATA_HI);
+
+	/* Our hardware does not associate any VID to the FDB entries so this
+	 * means that if two entries were added for the same mac but for
+	 * different VID, then, on the deletion of the first one, we would also
+	 * delete the second one. Since there is unfortunately nothing we can do
+	 * about that, do not return an error...
+	 */
+	if (!lk_data.entry.valid)
+		goto lk_unlock;
+
+	lk_data.entry.port_mask &= ~BIT(port);
+	/* If there is no more port in the mask, clear the entry */
+	if (lk_data.entry.port_mask == 0)
+		clear = true;
+
+	a5psw_reg_writel(a5psw, A5PSW_LK_DATA_HI, lk_data.hi);
+
+	reg = entry;
+	if (clear)
+		reg |= A5PSW_LK_ADDR_CTRL_CLEAR;
+	else
+		reg |= A5PSW_LK_ADDR_CTRL_WRITE;
+
+	ret = a5psw_lk_execute_ctrl(a5psw, &reg);
+	if (ret)
+		goto lk_unlock;
+
+	/* Decrement LEARNCOUNT */
+	if (clear) {
+		reg = A5PSW_LK_LEARNCOUNT_MODE_DEC;
+		a5psw_reg_writel(a5psw, A5PSW_LK_LEARNCOUNT, reg);
+	}
+
+lk_unlock:
+	spin_unlock(&a5psw->lk_lock);
+
+	return ret;
+}
+
+static int a5psw_port_fdb_dump(struct dsa_switch *ds, int port,
+			       dsa_fdb_dump_cb_t *cb, void *data)
+{
+	struct a5psw *a5psw = ds->priv;
+	union lk_data lk_data;
+	int i = 0, ret;
+	u32 reg;
+
+	for (i = 0; i < A5PSW_TABLE_ENTRIES; i++) {
+		reg = A5PSW_LK_ADDR_CTRL_READ | A5PSW_LK_ADDR_CTRL_WAIT | i;
+		spin_lock(&a5psw->lk_lock);
+
+		ret = a5psw_lk_execute_ctrl(a5psw, &reg);
+		if (ret) {
+			spin_unlock(&a5psw->lk_lock);
+			return ret;
+		}
+
+		lk_data.hi = a5psw_reg_readl(a5psw, A5PSW_LK_DATA_HI);
+		/* If entry is not valid or does not contain the port, skip */
+		if (!lk_data.entry.valid ||
+		    !(lk_data.entry.port_mask & BIT(port))) {
+			spin_unlock(&a5psw->lk_lock);
+			continue;
+		}
+
+		lk_data.lo = a5psw_reg_readl(a5psw, A5PSW_LK_DATA_LO);
+		spin_unlock(&a5psw->lk_lock);
+
+		ret = cb(lk_data.entry.mac, 0, lk_data.entry.is_static, data);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static u64 a5psw_read_stat(struct a5psw *a5psw, u32 offset, int port)
 {
 	u32 reg_lo, reg_hi;
@@ -596,6 +762,9 @@ static const struct dsa_switch_ops a5psw_switch_ops = {
 	.port_bridge_leave = a5psw_port_bridge_leave,
 	.port_stp_state_set = a5psw_port_stp_state_set,
 	.port_fast_age = a5psw_port_fast_age,
+	.port_fdb_add = a5psw_port_fdb_add,
+	.port_fdb_del = a5psw_port_fdb_del,
+	.port_fdb_dump = a5psw_port_fdb_dump,
 };
 
 static int a5psw_mdio_wait_busy(struct a5psw *a5psw)
diff --git a/drivers/net/dsa/rzn1_a5psw.h b/drivers/net/dsa/rzn1_a5psw.h
index 649165d37fde..14fffff10621 100644
--- a/drivers/net/dsa/rzn1_a5psw.h
+++ b/drivers/net/dsa/rzn1_a5psw.h
@@ -211,6 +211,23 @@
 #define A5PSW_CTRL_TIMEOUT		1000
 #define A5PSW_TABLE_ENTRIES		8192
 
+struct fdb_entry {
+	u8 mac[ETH_ALEN];
+	u16 valid:1;
+	u16 is_static:1;
+	u16 prio:3;
+	u16 port_mask:5;
+	u16 reserved:6;
+} __packed;
+
+union lk_data {
+	struct {
+		u32 lo;
+		u32 hi;
+	};
+	struct fdb_entry entry;
+};
+
 /**
  * struct a5psw - switch struct
  * @base: Base address of the switch
-- 
2.36.0