net: convert SMSC USB net drivers to hw_features

There's a race (not fixed here) in smsc75xx in setting RFE_CTL that's not
properly handled via rfe_ctl_lock. Spinlock is not a good tool here, as
this has to wait for URB completion (or maybe just submission) after issuing
register write request. Otherwise, the rfe_ctl might be changed just after
spin_unlock() and device left programmed with other value.

smsc95xx has increased hard_header_len for the case of TX checksumming.

smsc75xx is fixed to advertise IP+IPV6_CSUM instead of HW_CSUM as it does
not use csum_start/csum_offset.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 63 insertions, 144 deletions

diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c
index 753ee6eb7edd..860a20c938b4 100644
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -65,7 +65,6 @@ struct smsc75xx_priv {
         struct usbnet *dev;
         u32 rfe_ctl;
         u32 multicast_hash_table[DP_SEL_VHF_HASH_LEN];
-        bool use_rx_csum;
         struct mutex dataport_mutex;
         spinlock_t rfe_ctl_lock;
         struct work_struct set_multicast;
@@ -548,28 +547,6 @@ static void smsc75xx_status(struct usbnet *dev, struct urb *urb)
                         "unexpected interrupt, intdata=0x%08X", intdata);
 }
 
-/* Enable or disable Rx checksum offload engine */
-static int smsc75xx_set_rx_csum_offload(struct usbnet *dev)
-{
-        struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);
-        unsigned long flags;
-        int ret;
-
-        spin_lock_irqsave(&pdata->rfe_ctl_lock, flags);
-
-        if (pdata->use_rx_csum)
-                pdata->rfe_ctl |= RFE_CTL_TCPUDP_CKM | RFE_CTL_IP_CKM;
-        else
-                pdata->rfe_ctl &= ~(RFE_CTL_TCPUDP_CKM | RFE_CTL_IP_CKM);
-
-        spin_unlock_irqrestore(&pdata->rfe_ctl_lock, flags);
-
-        ret = smsc75xx_write_reg(dev, RFE_CTL, pdata->rfe_ctl);
-        check_warn_return(ret, "Error writing RFE_CTL");
-
-        return 0;
-}
-
 static int smsc75xx_ethtool_get_eeprom_len(struct net_device *net)
 {
         return MAX_EEPROM_SIZE;
@@ -599,34 +576,6 @@ static int smsc75xx_ethtool_set_eeprom(struct net_device *netdev,
         return smsc75xx_write_eeprom(dev, ee->offset, ee->len, data);
 }
 
-static u32 smsc75xx_ethtool_get_rx_csum(struct net_device *netdev)
-{
-        struct usbnet *dev = netdev_priv(netdev);
-        struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);
-
-        return pdata->use_rx_csum;
-}
-
-static int smsc75xx_ethtool_set_rx_csum(struct net_device *netdev, u32 val)
-{
-        struct usbnet *dev = netdev_priv(netdev);
-        struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);
-
-        pdata->use_rx_csum = !!val;
-
-        return smsc75xx_set_rx_csum_offload(dev);
-}
-
-static int smsc75xx_ethtool_set_tso(struct net_device *netdev, u32 data)
-{
-        if (data)
-                netdev->features |= NETIF_F_TSO | NETIF_F_TSO6;
-        else
-                netdev->features &= ~(NETIF_F_TSO | NETIF_F_TSO6);
-
-        return 0;
-}
-
 static const struct ethtool_ops smsc75xx_ethtool_ops = {
         .get_link       = usbnet_get_link,
         .nway_reset     = usbnet_nway_reset,
@@ -638,12 +587,6 @@ static const struct ethtool_ops smsc75xx_ethtool_ops = {
         .get_eeprom_len = smsc75xx_ethtool_get_eeprom_len,
         .get_eeprom     = smsc75xx_ethtool_get_eeprom,
         .set_eeprom     = smsc75xx_ethtool_set_eeprom,
-        .get_tx_csum    = ethtool_op_get_tx_csum,
-        .set_tx_csum    = ethtool_op_set_tx_hw_csum,
-        .get_rx_csum    = smsc75xx_ethtool_get_rx_csum,
-        .set_rx_csum    = smsc75xx_ethtool_set_rx_csum,
-        .get_tso        = ethtool_op_get_tso,
-        .set_tso        = smsc75xx_ethtool_set_tso,
 };
 
 static int smsc75xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
@@ -782,6 +725,30 @@ static int smsc75xx_change_mtu(struct net_device *netdev, int new_mtu)
         return usbnet_change_mtu(netdev, new_mtu);
 }
 
+/* Enable or disable Rx checksum offload engine */
+static int smsc75xx_set_features(struct net_device *netdev, u32 features)
+{
+        struct usbnet *dev = netdev_priv(netdev);
+        struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&pdata->rfe_ctl_lock, flags);
+
+        if (features & NETIF_F_RXCSUM)
+                pdata->rfe_ctl |= RFE_CTL_TCPUDP_CKM | RFE_CTL_IP_CKM;
+        else
+                pdata->rfe_ctl &= ~(RFE_CTL_TCPUDP_CKM | RFE_CTL_IP_CKM);
+
+        spin_unlock_irqrestore(&pdata->rfe_ctl_lock, flags);
+        /* it's racing here! */
+
+        ret = smsc75xx_write_reg(dev, RFE_CTL, pdata->rfe_ctl);
+        check_warn_return(ret, "Error writing RFE_CTL");
+
+        return 0;
+}
+
 static int smsc75xx_reset(struct usbnet *dev)
 {
         struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);
@@ -960,11 +927,7 @@ static int smsc75xx_reset(struct usbnet *dev)
         netif_dbg(dev, ifup, dev->net, "RFE_CTL set to 0x%08x", pdata->rfe_ctl);
 
         /* Enable or disable checksum offload engines */
-        ethtool_op_set_tx_hw_csum(dev->net, DEFAULT_TX_CSUM_ENABLE);
-        ret = smsc75xx_set_rx_csum_offload(dev);
-        check_warn_return(ret, "Failed to set rx csum offload: %d", ret);
-
-        smsc75xx_ethtool_set_tso(dev->net, DEFAULT_TSO_ENABLE);
+        smsc75xx_set_features(dev->net, dev->net->features);
 
         smsc75xx_set_multicast(dev->net);
 
@@ -1037,6 +1000,7 @@ static const struct net_device_ops smsc75xx_netdev_ops = {
         .ndo_validate_addr      = eth_validate_addr,
         .ndo_do_ioctl           = smsc75xx_ioctl,
         .ndo_set_multicast_list = smsc75xx_set_multicast,
+        .ndo_set_features       = smsc75xx_set_features,
 };
 
 static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf)
@@ -1065,10 +1029,17 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf)
 
         INIT_WORK(&pdata->set_multicast, smsc75xx_deferred_multicast_write);
 
-        pdata->use_rx_csum = DEFAULT_RX_CSUM_ENABLE;
+        if (DEFAULT_TX_CSUM_ENABLE) {
+                dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+                if (DEFAULT_TSO_ENABLE)
+                        dev->net->features |= NETIF_F_SG |
+                                NETIF_F_TSO | NETIF_F_TSO6;
+        }
+        if (DEFAULT_RX_CSUM_ENABLE)
+                dev->net->features |= NETIF_F_RXCSUM;
 
-        /* We have to advertise SG otherwise TSO cannot be enabled */
-        dev->net->features |= NETIF_F_SG;
+        dev->net->hw_features = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+                NETIF_F_SG | NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_RXCSUM;
 
         /* Init all registers */
         ret = smsc75xx_reset(dev);
@@ -1091,10 +1062,11 @@ static void smsc75xx_unbind(struct usbnet *dev, struct usb_interface *intf)
         }
 }
 
-static void smsc75xx_rx_csum_offload(struct sk_buff *skb, u32 rx_cmd_a,
-                                     u32 rx_cmd_b)
+static void smsc75xx_rx_csum_offload(struct usbnet *dev, struct sk_buff *skb,
+                                     u32 rx_cmd_a, u32 rx_cmd_b)
 {
-        if (unlikely(rx_cmd_a & RX_CMD_A_LCSM)) {
+        if (!(dev->net->features & NETIF_F_RXCSUM) ||
+            unlikely(rx_cmd_a & RX_CMD_A_LCSM)) {
                 skb->ip_summed = CHECKSUM_NONE;
         } else {
                 skb->csum = ntohs((u16)(rx_cmd_b >> RX_CMD_B_CSUM_SHIFT));
@@ -1104,8 +1076,6 @@ static void smsc75xx_rx_csum_offload(struct sk_buff *skb, u32 rx_cmd_a,
 
 static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 {
-        struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);
-
         while (skb->len > 0) {
                 u32 rx_cmd_a, rx_cmd_b, align_count, size;
                 struct sk_buff *ax_skb;
@@ -1145,11 +1115,8 @@ static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 
                         /* last frame in this batch */
                         if (skb->len == size) {
-                                if (pdata->use_rx_csum)
-                                        smsc75xx_rx_csum_offload(skb, rx_cmd_a,
-                                                rx_cmd_b);
-                                else
-                                        skb->ip_summed = CHECKSUM_NONE;
+                                smsc75xx_rx_csum_offload(dev, skb, rx_cmd_a,
+                                        rx_cmd_b);
 
                                 skb_trim(skb, skb->len - 4); /* remove fcs */
                                 skb->truesize = size + sizeof(struct sk_buff);
@@ -1167,11 +1134,8 @@ static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
                         ax_skb->data = packet;
                         skb_set_tail_pointer(ax_skb, size);
 
-                        if (pdata->use_rx_csum)
-                                smsc75xx_rx_csum_offload(ax_skb, rx_cmd_a,
-                                        rx_cmd_b);
-                        else
-                                ax_skb->ip_summed = CHECKSUM_NONE;
+                        smsc75xx_rx_csum_offload(dev, ax_skb, rx_cmd_a,
+                                rx_cmd_b);
 
                         skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */
                         ax_skb->truesize = size + sizeof(struct sk_buff);
diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 727874d9deb6..708f2083898b 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -52,8 +52,6 @@ struct smsc95xx_priv {
         u32 hash_hi;
         u32 hash_lo;
         spinlock_t mac_cr_lock;
-        bool use_tx_csum;
-        bool use_rx_csum;
 };
 
 struct usb_context {
@@ -517,22 +515,24 @@ static void smsc95xx_status(struct usbnet *dev, struct urb *urb)
 }
 
 /* Enable or disable Tx & Rx checksum offload engines */
-static int smsc95xx_set_csums(struct usbnet *dev)
+static int smsc95xx_set_features(struct net_device *netdev, u32 features)
 {
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
+        struct usbnet *dev = netdev_priv(netdev);
         u32 read_buf;
-        int ret = smsc95xx_read_reg(dev, COE_CR, &read_buf);
+        int ret;
+
+        ret = smsc95xx_read_reg(dev, COE_CR, &read_buf);
         if (ret < 0) {
                 netdev_warn(dev->net, "Failed to read COE_CR: %d\n", ret);
                 return ret;
         }
 
-        if (pdata->use_tx_csum)
+        if (features & NETIF_F_HW_CSUM)
                 read_buf |= Tx_COE_EN_;
         else
                 read_buf &= ~Tx_COE_EN_;
 
-        if (pdata->use_rx_csum)
+        if (features & NETIF_F_RXCSUM)
                 read_buf |= Rx_COE_EN_;
         else
                 read_buf &= ~Rx_COE_EN_;
@@ -576,43 +576,6 @@ static int smsc95xx_ethtool_set_eeprom(struct net_device *netdev,
         return smsc95xx_write_eeprom(dev, ee->offset, ee->len, data);
 }
 
-static u32 smsc95xx_ethtool_get_rx_csum(struct net_device *netdev)
-{
-        struct usbnet *dev = netdev_priv(netdev);
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-
-        return pdata->use_rx_csum;
-}
-
-static int smsc95xx_ethtool_set_rx_csum(struct net_device *netdev, u32 val)
-{
-        struct usbnet *dev = netdev_priv(netdev);
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-
-        pdata->use_rx_csum = !!val;
-
-        return smsc95xx_set_csums(dev);
-}
-
-static u32 smsc95xx_ethtool_get_tx_csum(struct net_device *netdev)
-{
-        struct usbnet *dev = netdev_priv(netdev);
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-
-        return pdata->use_tx_csum;
-}
-
-static int smsc95xx_ethtool_set_tx_csum(struct net_device *netdev, u32 val)
-{
-        struct usbnet *dev = netdev_priv(netdev);
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-
-        pdata->use_tx_csum = !!val;
-
-        ethtool_op_set_tx_hw_csum(netdev, pdata->use_tx_csum);
-        return smsc95xx_set_csums(dev);
-}
-
 static const struct ethtool_ops smsc95xx_ethtool_ops = {
         .get_link       = usbnet_get_link,
         .nway_reset     = usbnet_nway_reset,
@@ -624,10 +587,6 @@ static const struct ethtool_ops smsc95xx_ethtool_ops = {
         .get_eeprom_len = smsc95xx_ethtool_get_eeprom_len,
         .get_eeprom     = smsc95xx_ethtool_get_eeprom,
         .set_eeprom     = smsc95xx_ethtool_set_eeprom,
-        .get_tx_csum    = smsc95xx_ethtool_get_tx_csum,
-        .set_tx_csum    = smsc95xx_ethtool_set_tx_csum,
-        .get_rx_csum    = smsc95xx_ethtool_get_rx_csum,
-        .set_rx_csum    = smsc95xx_ethtool_set_rx_csum,
 };
 
 static int smsc95xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
@@ -755,7 +714,6 @@ static int smsc95xx_phy_initialize(struct usbnet *dev)
 static int smsc95xx_reset(struct usbnet *dev)
 {
         struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-        struct net_device *netdev = dev->net;
         u32 read_buf, write_buf, burst_cap;
         int ret = 0, timeout;
 
@@ -975,12 +933,7 @@ static int smsc95xx_reset(struct usbnet *dev)
         }
 
         /* Enable or disable checksum offload engines */
-        ethtool_op_set_tx_hw_csum(netdev, pdata->use_tx_csum);
-        ret = smsc95xx_set_csums(dev);
-        if (ret < 0) {
-                netdev_warn(dev->net, "Failed to set csum offload: %d\n", ret);
-                return ret;
-        }
+        smsc95xx_set_features(dev->net, dev->net->features);
 
         smsc95xx_set_multicast(dev->net);
 
@@ -1019,6 +972,7 @@ static const struct net_device_ops smsc95xx_netdev_ops = {
         .ndo_validate_addr      = eth_validate_addr,
         .ndo_do_ioctl           = smsc95xx_ioctl,
         .ndo_set_multicast_list = smsc95xx_set_multicast,
+        .ndo_set_features       = smsc95xx_set_features,
 };
 
 static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
@@ -1045,8 +999,12 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
 
         spin_lock_init(&pdata->mac_cr_lock);
 
-        pdata->use_tx_csum = DEFAULT_TX_CSUM_ENABLE;
-        pdata->use_rx_csum = DEFAULT_RX_CSUM_ENABLE;
+        if (DEFAULT_TX_CSUM_ENABLE)
+                dev->net->features |= NETIF_F_HW_CSUM;
+        if (DEFAULT_RX_CSUM_ENABLE)
+                dev->net->features |= NETIF_F_RXCSUM;
+
+        dev->net->hw_features = NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
 
         smsc95xx_init_mac_address(dev);
 
@@ -1056,7 +1014,7 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf)
         dev->net->netdev_ops = &smsc95xx_netdev_ops;
         dev->net->ethtool_ops = &smsc95xx_ethtool_ops;
         dev->net->flags |= IFF_MULTICAST;
-        dev->net->hard_header_len += SMSC95XX_TX_OVERHEAD;
+        dev->net->hard_header_len += SMSC95XX_TX_OVERHEAD_CSUM;
         return 0;
 }
 
@@ -1080,8 +1038,6 @@ static void smsc95xx_rx_csum_offload(struct sk_buff *skb)
 
 static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 {
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-
         while (skb->len > 0) {
                 u32 header, align_count;
                 struct sk_buff *ax_skb;
@@ -1123,7 +1079,7 @@ static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 
                         /* last frame in this batch */
                         if (skb->len == size) {
-                                if (pdata->use_rx_csum)
+                                if (dev->net->features & NETIF_F_RXCSUM)
                                         smsc95xx_rx_csum_offload(skb);
                                 skb_trim(skb, skb->len - 4); /* remove fcs */
                                 skb->truesize = size + sizeof(struct sk_buff);
@@ -1141,7 +1097,7 @@ static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
                         ax_skb->data = packet;
                         skb_set_tail_pointer(ax_skb, size);
 
-                        if (pdata->use_rx_csum)
+                        if (dev->net->features & NETIF_F_RXCSUM)
                                 smsc95xx_rx_csum_offload(ax_skb);
                         skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */
                         ax_skb->truesize = size + sizeof(struct sk_buff);
@@ -1174,8 +1130,7 @@ static u32 smsc95xx_calc_csum_preamble(struct sk_buff *skb)
 static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
                                          struct sk_buff *skb, gfp_t flags)
 {
-        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
-        bool csum = pdata->use_tx_csum && (skb->ip_summed == CHECKSUM_PARTIAL);
+        bool csum = skb->ip_summed == CHECKSUM_PARTIAL;
         int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM : SMSC95XX_TX_OVERHEAD;
         u32 tx_cmd_a, tx_cmd_b;