net: stmmac: Let descriptor code clear the descriptor

Stop using if conditions depending on the GMAC version for clearing the
descriptor and use instead a helper implemented in the descriptor files.
Signed-off-by: NJose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c

@@ -430,6 +430,14 @@ static void dwmac4_set_addr(struct dma_desc *p, dma_addr_t addr)
 	p->des1 = 0;
 }
 
+static void dwmac4_clear(struct dma_desc *p)
+{
+	p->des0 = 0;
+	p->des1 = 0;
+	p->des2 = 0;
+	p->des3 = 0;
+}
+
 const struct stmmac_desc_ops dwmac4_desc_ops = {
 	.tx_status = dwmac4_wrback_get_tx_status,
 	.rx_status = dwmac4_wrback_get_rx_status,
@@ -452,6 +460,7 @@ const struct stmmac_desc_ops dwmac4_desc_ops = {
 	.display_ring = dwmac4_display_ring,
 	.set_mss = dwmac4_set_mss_ctxt,
 	.set_addr = dwmac4_set_addr,
+	.clear = dwmac4_clear,
 };
 
 const struct stmmac_mode_ops dwmac4_ring_mode_ops = { };

drivers/net/ethernet/stmicro/stmmac/enh_desc.c

@@ -442,6 +442,11 @@ static void enh_desc_set_addr(struct dma_desc *p, dma_addr_t addr)
 	p->des2 = cpu_to_le32(addr);
 }
 
+static void enh_desc_clear(struct dma_desc *p)
+{
+	p->des2 = 0;
+}
+
 const struct stmmac_desc_ops enh_desc_ops = {
 	.tx_status = enh_desc_get_tx_status,
 	.rx_status = enh_desc_get_rx_status,
@@ -463,4 +468,5 @@ const struct stmmac_desc_ops enh_desc_ops = {
 	.get_rx_timestamp_status = enh_desc_get_rx_timestamp_status,
 	.display_ring = enh_desc_display_ring,
 	.set_addr = enh_desc_set_addr,
+	.clear = enh_desc_clear,
 };

drivers/net/ethernet/stmicro/stmmac/hwif.h

@@ -81,6 +81,8 @@ struct stmmac_desc_ops {
 	void (*set_mss)(struct dma_desc *p, unsigned int mss);
 	/* set descriptor skbuff address */
 	void (*set_addr)(struct dma_desc *p, dma_addr_t addr);
+	/* clear descriptor */
+	void (*clear)(struct dma_desc *p);
 };
 
 #define stmmac_init_rx_desc(__priv, __args...) \
@@ -127,6 +129,8 @@ struct stmmac_desc_ops {
 	stmmac_do_void_callback(__priv, desc, set_mss, __args)
 #define stmmac_set_desc_addr(__priv, __args...) \
 	stmmac_do_void_callback(__priv, desc, set_addr, __args)
+#define stmmac_clear_desc(__priv, __args...) \
+	stmmac_do_void_callback(__priv, desc, clear, __args)
 
 struct stmmac_dma_cfg;
 struct dma_features;

drivers/net/ethernet/stmicro/stmmac/norm_desc.c

@@ -302,6 +302,11 @@ static void ndesc_set_addr(struct dma_desc *p, dma_addr_t addr)
 	p->des2 = cpu_to_le32(addr);
 }
 
+static void ndesc_clear(struct dma_desc *p)
+{
+	p->des2 = 0;
+}
+
 const struct stmmac_desc_ops ndesc_ops = {
 	.tx_status = ndesc_get_tx_status,
 	.rx_status = ndesc_get_rx_status,
@@ -322,4 +327,5 @@ const struct stmmac_desc_ops ndesc_ops = {
 	.get_rx_timestamp_status = ndesc_get_rx_timestamp_status,
 	.display_ring = ndesc_display_ring,
 	.set_addr = ndesc_set_addr,
+	.clear = ndesc_clear,
 };

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1341,14 +1341,7 @@ static int init_dma_tx_desc_rings(struct net_device *dev)
 			else
 				p = tx_q->dma_tx + i;
 
-			if (priv->synopsys_id >= DWMAC_CORE_4_00) {
-				p->des0 = 0;
-				p->des1 = 0;
-				p->des2 = 0;
-				p->des3 = 0;
-			} else {
-				p->des2 = 0;
-			}
+			stmmac_clear_desc(priv, p);
 
 			tx_q->tx_skbuff_dma[i].buf = 0;
 			tx_q->tx_skbuff_dma[i].map_as_page = false;