drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c

   1 /* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  *
  13  * RMNET Data virtual network driver
  14  *
  15  */
  16
  17 #include <linux/etherdevice.h>
  18 #include <linux/if_arp.h>
  19 #include <net/pkt_sched.h>
  20 #include "rmnet_config.h"
  21 #include "rmnet_handlers.h"
  22 #include "rmnet_private.h"
  23 #include "rmnet_map.h"
  24 #include "rmnet_vnd.h"
  25
  26 /* RX/TX Fixup */
  27
  28 void rmnet_vnd_rx_fixup(struct sk_buff *skb, struct net_device *dev)
  29 {
  30         struct rmnet_priv *priv = netdev_priv(dev);
  31         struct rmnet_pcpu_stats *pcpu_ptr;
  32
  33         pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
  34
  35         u64_stats_update_begin(&pcpu_ptr->syncp);
  36         pcpu_ptr->stats.rx_pkts++;
  37         pcpu_ptr->stats.rx_bytes += skb->len;
  38         u64_stats_update_end(&pcpu_ptr->syncp);
  39 }
  40
  41 void rmnet_vnd_tx_fixup(struct sk_buff *skb, struct net_device *dev)
  42 {
  43         struct rmnet_priv *priv = netdev_priv(dev);
  44         struct rmnet_pcpu_stats *pcpu_ptr;
  45
  46         pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
  47
  48         u64_stats_update_begin(&pcpu_ptr->syncp);
  49         pcpu_ptr->stats.tx_pkts++;
  50         pcpu_ptr->stats.tx_bytes += skb->len;
  51         u64_stats_update_end(&pcpu_ptr->syncp);
  52 }
  53
  54 /* Network Device Operations */
  55
  56 static netdev_tx_t rmnet_vnd_start_xmit(struct sk_buff *skb,
  57                                         struct net_device *dev)
  58 {
  59         struct rmnet_priv *priv;
  60
  61         priv = netdev_priv(dev);
  62         if (priv->real_dev) {
  63                 rmnet_egress_handler(skb);
  64         } else {
  65                 this_cpu_inc(priv->pcpu_stats->stats.tx_drops);
  66                 kfree_skb(skb);
  67         }
  68         return NETDEV_TX_OK;
  69 }
  70
  71 static int rmnet_vnd_change_mtu(struct net_device *rmnet_dev, int new_mtu)
  72 {
  73         if (new_mtu < 0 || new_mtu > RMNET_MAX_PACKET_SIZE)
  74                 return -EINVAL;
  75
  76         rmnet_dev->mtu = new_mtu;
  77         return 0;
  78 }
  79
  80 static int rmnet_vnd_get_iflink(const struct net_device *dev)
  81 {
  82         struct rmnet_priv *priv = netdev_priv(dev);
  83
  84         return priv->real_dev->ifindex;
  85 }
  86
  87 static int rmnet_vnd_init(struct net_device *dev)
  88 {
  89         struct rmnet_priv *priv = netdev_priv(dev);
  90         int err;
  91
  92         priv->pcpu_stats = alloc_percpu(struct rmnet_pcpu_stats);
  93         if (!priv->pcpu_stats)
  94                 return -ENOMEM;
  95
  96         err = gro_cells_init(&priv->gro_cells, dev);
  97         if (err) {
  98                 free_percpu(priv->pcpu_stats);
  99                 return err;
 100         }
 101
 102         return 0;
 103 }
 104
 105 static void rmnet_vnd_uninit(struct net_device *dev)
 106 {
 107         struct rmnet_priv *priv = netdev_priv(dev);
 108
 109         gro_cells_destroy(&priv->gro_cells);
 110         free_percpu(priv->pcpu_stats);
 111 }
 112
 113 static void rmnet_get_stats64(struct net_device *dev,
 114                               struct rtnl_link_stats64 *s)
 115 {
 116         struct rmnet_priv *priv = netdev_priv(dev);
 117         struct rmnet_vnd_stats total_stats;
 118         struct rmnet_pcpu_stats *pcpu_ptr;
 119         unsigned int cpu, start;
 120
 121         memset(&total_stats, 0, sizeof(struct rmnet_vnd_stats));
 122
 123         for_each_possible_cpu(cpu) {
 124                 pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
 125
 126                 do {
 127                         start = u64_stats_fetch_begin_irq(&pcpu_ptr->syncp);
 128                         total_stats.rx_pkts += pcpu_ptr->stats.rx_pkts;
 129                         total_stats.rx_bytes += pcpu_ptr->stats.rx_bytes;
 130                         total_stats.tx_pkts += pcpu_ptr->stats.tx_pkts;
 131                         total_stats.tx_bytes += pcpu_ptr->stats.tx_bytes;
 132                 } while (u64_stats_fetch_retry_irq(&pcpu_ptr->syncp, start));
 133
 134                 total_stats.tx_drops += pcpu_ptr->stats.tx_drops;
 135         }
 136
 137         s->rx_packets = total_stats.rx_pkts;
 138         s->rx_bytes = total_stats.rx_bytes;
 139         s->tx_packets = total_stats.tx_pkts;
 140         s->tx_bytes = total_stats.tx_bytes;
 141         s->tx_dropped = total_stats.tx_drops;
 142 }
 143
 144 static const struct net_device_ops rmnet_vnd_ops = {
 145         .ndo_start_xmit = rmnet_vnd_start_xmit,
 146         .ndo_change_mtu = rmnet_vnd_change_mtu,
 147         .ndo_get_iflink = rmnet_vnd_get_iflink,
 148         .ndo_add_slave  = rmnet_add_bridge,
 149         .ndo_del_slave  = rmnet_del_bridge,
 150         .ndo_init       = rmnet_vnd_init,
 151         .ndo_uninit     = rmnet_vnd_uninit,
 152         .ndo_get_stats64 = rmnet_get_stats64,
 153 };
 154
 155 /* Called by kernel whenever a new rmnet<n> device is created. Sets MTU,
 156  * flags, ARP type, needed headroom, etc...
 157  */
 158 void rmnet_vnd_setup(struct net_device *rmnet_dev)
 159 {
 160         rmnet_dev->netdev_ops = &rmnet_vnd_ops;
 161         rmnet_dev->mtu = RMNET_DFLT_PACKET_SIZE;
 162         rmnet_dev->needed_headroom = RMNET_NEEDED_HEADROOM;
 163         random_ether_addr(rmnet_dev->dev_addr);
 164         rmnet_dev->tx_queue_len = RMNET_TX_QUEUE_LEN;
 165
 166         /* Raw IP mode */
 167         rmnet_dev->header_ops = NULL;  /* No header */
 168         rmnet_dev->type = ARPHRD_RAWIP;
 169         rmnet_dev->hard_header_len = 0;
 170         rmnet_dev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
 171
 172         rmnet_dev->needs_free_netdev = true;
 173 }
 174
 175 /* Exposed API */
 176
 177 int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
 178                       struct rmnet_port *port,
 179                       struct net_device *real_dev,
 180                       struct rmnet_endpoint *ep)
 181 {
 182         struct rmnet_priv *priv;
 183         int rc;
 184
 185         if (ep->egress_dev)
 186                 return -EINVAL;
 187
 188         if (rmnet_get_endpoint(port, id))
 189                 return -EBUSY;
 190
 191         rmnet_dev->hw_features = NETIF_F_RXCSUM;
 192         rmnet_dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
 193         rmnet_dev->hw_features |= NETIF_F_SG;
 194
 195         rc = register_netdevice(rmnet_dev);
 196         if (!rc) {
 197                 ep->egress_dev = rmnet_dev;
 198                 ep->mux_id = id;
 199                 port->nr_rmnet_devs++;
 200
 201                 rmnet_dev->rtnl_link_ops = &rmnet_link_ops;
 202
 203                 priv = netdev_priv(rmnet_dev);
 204                 priv->mux_id = id;
 205                 priv->real_dev = real_dev;
 206
 207                 netdev_dbg(rmnet_dev, "rmnet dev created\n");
 208         }
 209
 210         return rc;
 211 }
 212
 213 int rmnet_vnd_dellink(u8 id, struct rmnet_port *port,
 214                       struct rmnet_endpoint *ep)
 215 {
 216         if (id >= RMNET_MAX_LOGICAL_EP || !ep->egress_dev)
 217                 return -EINVAL;
 218
 219         ep->egress_dev = NULL;
 220         port->nr_rmnet_devs--;
 221         return 0;
 222 }
 223
 224 u8 rmnet_vnd_get_mux(struct net_device *rmnet_dev)
 225 {
 226         struct rmnet_priv *priv;
 227
 228         priv = netdev_priv(rmnet_dev);
 229         return priv->mux_id;
 230 }
 231
 232 int rmnet_vnd_do_flow_control(struct net_device *rmnet_dev, int enable)
 233 {
 234         netdev_dbg(rmnet_dev, "Setting VND TX queue state to %d\n", enable);
 235         /* Although we expect similar number of enable/disable
 236          * commands, optimize for the disable. That is more
 237          * latency sensitive than enable
 238          */
 239         if (unlikely(enable))
 240                 netif_wake_queue(rmnet_dev);
 241         else
 242                 netif_stop_queue(rmnet_dev);
 243
 244         return 0;
 245 }