[PATCH v6 3/6] can: flexcan: split rx/tx masks per mailbox IRQ line

[Ciprian Costea <ciprianmarian.costea@oss.nxp.com>]

From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

On S32G2, which has two mailbox IRQ lines (mb-0 for MBs 0-7, mb-1
for MBs 8-63), both handlers currently process the full rx_mask/tx_mask
range.

Introduce FLEXCAN_SECONDARY_MB_IRQ_MB0_MASK and
FLEXCAN_SECONDARY_MB_IRQ_MB1_MASK to describe the split, and pass
the selected mask to flexcan_do_mb() via a new mb_mask parameter.

In flexcan_irq_mb(), the irq argument selects the correct mask: the
primary MB IRQ uses MB0_MASK and the secondary uses MB1_MASK.

For single-IRQ platforms, mb_mask is ~0ULL with no functional change.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
Reviewed-by: Vincent Mailhol <mailhol@kernel.org>
Reviewed-and-tested-by: Haibo Chen <haibo.chen@nxp.com>
Tested-by: Enric Balletbo i Serra <eballetb@redhat.com>
---
 drivers/net/can/flexcan/flexcan-core.c | 39 ++++++++++++++++++--------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index 7dde2e623def..8b70952f7f05 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -182,6 +182,12 @@
 #define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
 #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
 
+/* On platforms with FLEXCAN_QUIRK_SECONDARY_MB_IRQ, the MB IRQ lines are
+ * split.
+ */
+#define FLEXCAN_SECONDARY_MB_IRQ_MB0_MASK	GENMASK_U64(7, 0)
+#define FLEXCAN_SECONDARY_MB_IRQ_MB1_MASK	GENMASK_U64(63, 8)
+
 /* FLEXCAN message buffers */
 #define FLEXCAN_MB_CODE_MASK		(0xf << 24)
 #define FLEXCAN_MB_CODE_RX_BUSY_BIT	(0x1 << 24)
@@ -957,14 +963,16 @@ static inline void flexcan_write64(struct flexcan_priv *priv, u64 val, void __io
 		priv->write(lower_32_bits(val), addr);
 }
 
-static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
+static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv,
+					    u64 rx_mask)
 {
-	return flexcan_read64_mask(priv, &priv->regs->iflag1, priv->rx_mask);
+	return flexcan_read64_mask(priv, &priv->regs->iflag1, rx_mask);
 }
 
-static inline u64 flexcan_read_reg_iflag_tx(struct flexcan_priv *priv)
+static inline u64 flexcan_read_reg_iflag_tx(struct flexcan_priv *priv,
+					    u64 tx_mask)
 {
-	return flexcan_read64_mask(priv, &priv->regs->iflag1, priv->tx_mask);
+	return flexcan_read64_mask(priv, &priv->regs->iflag1, tx_mask);
 }
 
 static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *offload)
@@ -1071,12 +1079,14 @@ static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
 }
 
 /* Process mailbox (RX + TX) events */
-static irqreturn_t flexcan_do_mb(struct net_device *dev)
+static irqreturn_t flexcan_do_mb(struct net_device *dev, u64 mb_mask)
 {
 	struct net_device_stats *stats = &dev->stats;
 	struct flexcan_priv *priv = netdev_priv(dev);
 	struct flexcan_regs __iomem *regs = priv->regs;
 	irqreturn_t handled = IRQ_NONE;
+	u64 rx_mask = priv->rx_mask & mb_mask;
+	u64 tx_mask = priv->tx_mask & mb_mask;
 	u64 reg_iflag_tx;
 
 	/* reception interrupt */
@@ -1084,7 +1094,8 @@ static irqreturn_t flexcan_do_mb(struct net_device *dev)
 		u64 reg_iflag_rx;
 		int ret;
 
-		while ((reg_iflag_rx = flexcan_read_reg_iflag_rx(priv))) {
+		while ((reg_iflag_rx = flexcan_read_reg_iflag_rx(priv,
+								 rx_mask))) {
 			handled = IRQ_HANDLED;
 			ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
 								   reg_iflag_rx);
@@ -1110,10 +1121,10 @@ static irqreturn_t flexcan_do_mb(struct net_device *dev)
 		}
 	}
 
-	reg_iflag_tx = flexcan_read_reg_iflag_tx(priv);
+	reg_iflag_tx = flexcan_read_reg_iflag_tx(priv, tx_mask);
 
 	/* transmission complete interrupt */
-	if (reg_iflag_tx & priv->tx_mask) {
+	if (reg_iflag_tx & tx_mask) {
 		u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
 
 		handled = IRQ_HANDLED;
@@ -1125,7 +1136,7 @@ static irqreturn_t flexcan_do_mb(struct net_device *dev)
 		/* after sending a RTR frame MB is in RX mode */
 		priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
 			    &priv->tx_mb->can_ctrl);
-		flexcan_write64(priv, priv->tx_mask, &regs->iflag1);
+		flexcan_write64(priv, tx_mask, &regs->iflag1);
 		netif_wake_queue(dev);
 	}
 
@@ -1228,7 +1239,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	struct flexcan_priv *priv = netdev_priv(dev);
 	irqreturn_t handled;
 
-	handled = flexcan_do_mb(dev);
+	handled = flexcan_do_mb(dev, ~0ULL);
 	handled |= flexcan_do_state(dev);
 	handled |= flexcan_do_berr(dev);
 
@@ -1244,8 +1255,14 @@ static irqreturn_t flexcan_irq_mb(int irq, void *dev_id)
 	struct net_device *dev = dev_id;
 	struct flexcan_priv *priv = netdev_priv(dev);
 	irqreturn_t handled;
+	u64 mb_mask = ~0ULL;
+
+	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SECONDARY_MB_IRQ)
+		mb_mask = (irq == priv->irq_secondary_mb) ?
+			  FLEXCAN_SECONDARY_MB_IRQ_MB1_MASK :
+			  FLEXCAN_SECONDARY_MB_IRQ_MB0_MASK;
 
-	handled = flexcan_do_mb(dev);
+	handled = flexcan_do_mb(dev, mb_mask);
 
 	if (handled)
 		can_rx_offload_irq_finish(&priv->offload);
-- 
2.43.0