[PATCH net-next v2 3/3] net: stmmac: fpe: Move fprq configuration to stmmac_fpe_configure_pmac()

[muhammad . nazim . amirul . nazle . asmade]

From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>

The Frame Preemption Residue Queue (fprq) controls which Rx queue
receives residual preemptive mPackets from the pmac. This is a pmac
concern, not a TX concern, so move its configuration from
stmmac_fpe_configure_tx() to stmmac_fpe_configure_pmac() where it
logically belongs.

Keep the open-coded mask/shift update rather than u32_replace_bits(),
since fprq_mask is not a compile-time constant.

Signed-off-by: Rohan G Thomas <rohan.g.thomas@xxxxxxxxxx>
Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>
Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
---
v2: Drop u32_replace_bits(); fprq_mask is not a compile-time constant
    and triggered __bad_mask on x86. Keep open-coded mask/shift.
    Collect Reviewed-by from Maxime Chevallier.

 .../net/ethernet/stmicro/stmmac/stmmac_fpe.c  | 24 ++++++++++---------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
index 3436e962a238..55b4df3c677b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
@@ -47,20 +47,13 @@ static void stmmac_fpe_configure_tx(struct ethtool_mmsv *mmsv, bool tx_enable)
 	struct stmmac_fpe_cfg *cfg = container_of(mmsv, struct stmmac_fpe_cfg, mmsv);
 	struct stmmac_priv *priv = container_of(cfg, struct stmmac_priv, fpe_cfg);
 	const struct stmmac_fpe_reg *reg = cfg->reg;
-	u32 num_rxq = priv->plat->rx_queues_to_use;
 	void __iomem *ioaddr = priv->ioaddr;
-	u32 value;
 
-	if (tx_enable) {
+	if (tx_enable)
 		cfg->fpe_csr = STMMAC_MAC_FPE_CTRL_STS_EFPE;
-		value = readl(ioaddr + reg->rxq_ctrl1_reg);
-		value &= ~reg->fprq_mask;
-		/* Keep this SHIFT, FIELD_PREP() expects a constant mask :-/ */
-		value |= (num_rxq - 1) << __ffs(reg->fprq_mask);
-		writel(value, ioaddr + reg->rxq_ctrl1_reg);
-	} else {
+	else
 		cfg->fpe_csr = 0;
-	}
+
 	writel(cfg->fpe_csr, ioaddr + reg->mac_fpe_reg);
 }
 
@@ -68,10 +61,11 @@ static void stmmac_fpe_configure_pmac(struct ethtool_mmsv *mmsv, bool pmac_enabl
 {
 	struct stmmac_fpe_cfg *cfg = container_of(mmsv, struct stmmac_fpe_cfg, mmsv);
 	struct stmmac_priv *priv = container_of(cfg, struct stmmac_priv, fpe_cfg);
+	u32 num_rxq = priv->plat->rx_queues_to_use;
 	const struct stmmac_fpe_reg *reg = cfg->reg;
 	void __iomem *ioaddr = priv->ioaddr;
 	unsigned long flags;
-	u32 value;
+	u32 value, value_2;
 
 	spin_lock_irqsave(&priv->hw->irq_ctrl_lock, flags);
 	value = readl(ioaddr + reg->int_en_reg);
@@ -83,6 +77,14 @@ static void stmmac_fpe_configure_pmac(struct ethtool_mmsv *mmsv, bool pmac_enabl
 
 			value |= reg->int_en_bit;
 		}
+		/* Frame Preemption Residue Queue is the Rx Queue to which
+		 * residual preemptive mPackets must be forwarded from the pmac.
+		 */
+		value_2 = readl(ioaddr + reg->rxq_ctrl1_reg);
+		value_2 &= ~reg->fprq_mask;
+		/* Keep this SHIFT, FIELD_PREP() expects a constant mask :-/ */
+		value_2 |= (num_rxq - 1) << __ffs(reg->fprq_mask);
+		writel(value_2, ioaddr + reg->rxq_ctrl1_reg);
 	} else {
 		value &= ~reg->int_en_bit;
 	}
-- 
2.43.7