net: stmmac: Drop useless code related to ethtool rx-copybreak

After commit 2af6106 ("net: stmmac: Introducing support for Page
Pool"), the driver always copies frames to get a better performance,
zero-copy for RX frames is no more, then these code turned to be
useless and users of ethtool may get confused about the unhandled
rx-copybreak parameter.

This patch mostly reverts
commit 22ad383 ("stmmac: do not perform zero-copy for rx frames")

Signed-off-by: Furong Xu <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Furong Xu

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

@@ -126,7 +126,6 @@ struct stmmac_rx_queue {
 	unsigned int cur_rx;
 	unsigned int dirty_rx;
 	unsigned int buf_alloc_num;
-	u32 rx_zeroc_thresh;
 	dma_addr_t dma_rx_phy;
 	u32 rx_tail_addr;
 	unsigned int state_saved;
@@ -266,7 +265,6 @@ struct stmmac_priv {
 	int sph_cap;
 	u32 sarc_type;
 
-	unsigned int rx_copybreak;
 	u32 rx_riwt[MTL_MAX_TX_QUEUES];
 	int hwts_rx_en;
 

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

@@ -1227,43 +1227,6 @@ static int stmmac_get_ts_info(struct net_device *dev,
 		return ethtool_op_get_ts_info(dev, info);
 }
 
-static int stmmac_get_tunable(struct net_device *dev,
-			      const struct ethtool_tunable *tuna, void *data)
-{
-	struct stmmac_priv *priv = netdev_priv(dev);
-	int ret = 0;
-
-	switch (tuna->id) {
-	case ETHTOOL_RX_COPYBREAK:
-		*(u32 *)data = priv->rx_copybreak;
-		break;
-	default:
-		ret = -EINVAL;
-		break;
-	}
-
-	return ret;
-}
-
-static int stmmac_set_tunable(struct net_device *dev,
-			      const struct ethtool_tunable *tuna,
-			      const void *data)
-{
-	struct stmmac_priv *priv = netdev_priv(dev);
-	int ret = 0;
-
-	switch (tuna->id) {
-	case ETHTOOL_RX_COPYBREAK:
-		priv->rx_copybreak = *(u32 *)data;
-		break;
-	default:
-		ret = -EINVAL;
-		break;
-	}
-
-	return ret;
-}
-
 static int stmmac_get_mm(struct net_device *ndev,
 			 struct ethtool_mm_state *state)
 {
@@ -1390,8 +1353,6 @@ static const struct ethtool_ops stmmac_ethtool_ops = {
 	.set_per_queue_coalesce = stmmac_set_per_queue_coalesce,
 	.get_channels = stmmac_get_channels,
 	.set_channels = stmmac_set_channels,
-	.get_tunable = stmmac_get_tunable,
-	.set_tunable = stmmac_set_tunable,
 	.get_link_ksettings = stmmac_ethtool_get_link_ksettings,
 	.set_link_ksettings = stmmac_ethtool_set_link_ksettings,
 	.get_mm = stmmac_get_mm,

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

@@ -77,7 +77,6 @@ module_param(phyaddr, int, 0444);
 MODULE_PARM_DESC(phyaddr, "Physical device address");
 
 #define STMMAC_TX_THRESH(x)	((x)->dma_conf.dma_tx_size / 4)
-#define STMMAC_RX_THRESH(x)	((x)->dma_conf.dma_rx_size / 4)
 
 /* Limit to make sure XDP TX and slow path can coexist */
 #define STMMAC_XSK_TX_BUDGET_MAX	256
@@ -107,8 +106,6 @@ static int buf_sz = DEFAULT_BUFSIZE;
 module_param(buf_sz, int, 0644);
 MODULE_PARM_DESC(buf_sz, "DMA buffer size");
 
-#define	STMMAC_RX_COPYBREAK	256
-
 static const u32 default_msg_level = (NETIF_MSG_DRV | NETIF_MSG_PROBE |
 				      NETIF_MSG_LINK | NETIF_MSG_IFUP |
 				      NETIF_MSG_IFDOWN | NETIF_MSG_TIMER);
@@ -3927,8 +3924,6 @@ static int __stmmac_open(struct net_device *dev,
 		}
 	}
 
-	priv->rx_copybreak = STMMAC_RX_COPYBREAK;
-
 	buf_sz = dma_conf->dma_buf_sz;
 	for (int i = 0; i < MTL_MAX_TX_QUEUES; i++)
 		if (priv->dma_conf.tx_queue[i].tbs & STMMAC_TBS_EN)