net/dsa/dsa.c

   1 /*
   2  * net/dsa/dsa.c - Hardware switch handling
   3  * Copyright (c) 2008-2009 Marvell Semiconductor
   4  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/list.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/module.h>
  17 #include <linux/notifier.h>
  18 #include <linux/of.h>
  19 #include <linux/of_mdio.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/of_net.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/sysfs.h>
  24 #include <linux/phy_fixed.h>
  25 #include <linux/ptp_classify.h>
  26 #include <linux/etherdevice.h>
  27
  28 #include "dsa_priv.h"
  29
  30 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
  31                                             struct net_device *dev)
  32 {
  33         /* Just return the original SKB */
  34         return skb;
  35 }
  36
  37 static const struct dsa_device_ops none_ops = {
  38         .xmit   = dsa_slave_notag_xmit,
  39         .rcv    = NULL,
  40 };
  41
  42 const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
  43 #ifdef CONFIG_NET_DSA_TAG_BRCM
  44         [DSA_TAG_PROTO_BRCM] = &brcm_netdev_ops,
  45 #endif
  46 #ifdef CONFIG_NET_DSA_TAG_BRCM_PREPEND
  47         [DSA_TAG_PROTO_BRCM_PREPEND] = &brcm_prepend_netdev_ops,
  48 #endif
  49 #ifdef CONFIG_NET_DSA_TAG_DSA
  50         [DSA_TAG_PROTO_DSA] = &dsa_netdev_ops,
  51 #endif
  52 #ifdef CONFIG_NET_DSA_TAG_EDSA
  53         [DSA_TAG_PROTO_EDSA] = &edsa_netdev_ops,
  54 #endif
  55 #ifdef CONFIG_NET_DSA_TAG_GSWIP
  56         [DSA_TAG_PROTO_GSWIP] = &gswip_netdev_ops,
  57 #endif
  58 #ifdef CONFIG_NET_DSA_TAG_KSZ
  59         [DSA_TAG_PROTO_KSZ] = &ksz_netdev_ops,
  60 #endif
  61 #ifdef CONFIG_NET_DSA_TAG_LAN9303
  62         [DSA_TAG_PROTO_LAN9303] = &lan9303_netdev_ops,
  63 #endif
  64 #ifdef CONFIG_NET_DSA_TAG_MTK
  65         [DSA_TAG_PROTO_MTK] = &mtk_netdev_ops,
  66 #endif
  67 #ifdef CONFIG_NET_DSA_TAG_QCA
  68         [DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
  69 #endif
  70 #ifdef CONFIG_NET_DSA_TAG_TRAILER
  71         [DSA_TAG_PROTO_TRAILER] = &trailer_netdev_ops,
  72 #endif
  73         [DSA_TAG_PROTO_NONE] = &none_ops,
  74 };
  75
  76 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
  77 {
  78         const char *protocol_name[DSA_TAG_LAST] = {
  79 #ifdef CONFIG_NET_DSA_TAG_BRCM
  80                 [DSA_TAG_PROTO_BRCM] = "brcm",
  81 #endif
  82 #ifdef CONFIG_NET_DSA_TAG_BRCM_PREPEND
  83                 [DSA_TAG_PROTO_BRCM_PREPEND] = "brcm-prepend",
  84 #endif
  85 #ifdef CONFIG_NET_DSA_TAG_DSA
  86                 [DSA_TAG_PROTO_DSA] = "dsa",
  87 #endif
  88 #ifdef CONFIG_NET_DSA_TAG_EDSA
  89                 [DSA_TAG_PROTO_EDSA] = "edsa",
  90 #endif
  91 #ifdef CONFIG_NET_DSA_TAG_GSWIP
  92                 [DSA_TAG_PROTO_GSWIP] = "gswip",
  93 #endif
  94 #ifdef CONFIG_NET_DSA_TAG_KSZ
  95                 [DSA_TAG_PROTO_KSZ] = "ksz",
  96 #endif
  97 #ifdef CONFIG_NET_DSA_TAG_LAN9303
  98                 [DSA_TAG_PROTO_LAN9303] = "lan9303",
  99 #endif
 100 #ifdef CONFIG_NET_DSA_TAG_MTK
 101                 [DSA_TAG_PROTO_MTK] = "mtk",
 102 #endif
 103 #ifdef CONFIG_NET_DSA_TAG_QCA
 104                 [DSA_TAG_PROTO_QCA] = "qca",
 105 #endif
 106 #ifdef CONFIG_NET_DSA_TAG_TRAILER
 107                 [DSA_TAG_PROTO_TRAILER] = "trailer",
 108 #endif
 109                 [DSA_TAG_PROTO_NONE] = "none",
 110         };
 111         unsigned int i;
 112
 113         BUILD_BUG_ON(ARRAY_SIZE(protocol_name) != DSA_TAG_LAST);
 114
 115         for (i = 0; i < ARRAY_SIZE(dsa_device_ops); i++)
 116                 if (ops == dsa_device_ops[i])
 117                         return protocol_name[i];
 118
 119         return protocol_name[DSA_TAG_PROTO_NONE];
 120 };
 121
 122 const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol)
 123 {
 124         const struct dsa_device_ops *ops;
 125
 126         if (tag_protocol >= DSA_TAG_LAST)
 127                 return ERR_PTR(-EINVAL);
 128         ops = dsa_device_ops[tag_protocol];
 129
 130         if (!ops)
 131                 return ERR_PTR(-ENOPROTOOPT);
 132
 133         return ops;
 134 }
 135
 136 static int dev_is_class(struct device *dev, void *class)
 137 {
 138         if (dev->class != NULL && !strcmp(dev->class->name, class))
 139                 return 1;
 140
 141         return 0;
 142 }
 143
 144 static struct device *dev_find_class(struct device *parent, char *class)
 145 {
 146         if (dev_is_class(parent, class)) {
 147                 get_device(parent);
 148                 return parent;
 149         }
 150
 151         return device_find_child(parent, class, dev_is_class);
 152 }
 153
 154 struct net_device *dsa_dev_to_net_device(struct device *dev)
 155 {
 156         struct device *d;
 157
 158         d = dev_find_class(dev, "net");
 159         if (d != NULL) {
 160                 struct net_device *nd;
 161
 162                 nd = to_net_dev(d);
 163                 dev_hold(nd);
 164                 put_device(d);
 165
 166                 return nd;
 167         }
 168
 169         return NULL;
 170 }
 171 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
 172
 173 /* Determine if we should defer delivery of skb until we have a rx timestamp.
 174  *
 175  * Called from dsa_switch_rcv. For now, this will only work if tagging is
 176  * enabled on the switch. Normally the MAC driver would retrieve the hardware
 177  * timestamp when it reads the packet out of the hardware. However in a DSA
 178  * switch, the DSA driver owning the interface to which the packet is
 179  * delivered is never notified unless we do so here.
 180  */
 181 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
 182                                        struct sk_buff *skb)
 183 {
 184         struct dsa_switch *ds = p->dp->ds;
 185         unsigned int type;
 186
 187         if (skb_headroom(skb) < ETH_HLEN)
 188                 return false;
 189
 190         __skb_push(skb, ETH_HLEN);
 191
 192         type = ptp_classify_raw(skb);
 193
 194         __skb_pull(skb, ETH_HLEN);
 195
 196         if (type == PTP_CLASS_NONE)
 197                 return false;
 198
 199         if (likely(ds->ops->port_rxtstamp))
 200                 return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
 201
 202         return false;
 203 }
 204
 205 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 206                           struct packet_type *pt, struct net_device *unused)
 207 {
 208         struct dsa_port *cpu_dp = dev->dsa_ptr;
 209         struct sk_buff *nskb = NULL;
 210         struct pcpu_sw_netstats *s;
 211         struct dsa_slave_priv *p;
 212
 213         if (unlikely(!cpu_dp)) {
 214                 kfree_skb(skb);
 215                 return 0;
 216         }
 217
 218         skb = skb_unshare(skb, GFP_ATOMIC);
 219         if (!skb)
 220                 return 0;
 221
 222         nskb = cpu_dp->rcv(skb, dev, pt);
 223         if (!nskb) {
 224                 kfree_skb(skb);
 225                 return 0;
 226         }
 227
 228         skb = nskb;
 229         p = netdev_priv(skb->dev);
 230         skb_push(skb, ETH_HLEN);
 231         skb->pkt_type = PACKET_HOST;
 232         skb->protocol = eth_type_trans(skb, skb->dev);
 233
 234         s = this_cpu_ptr(p->stats64);
 235         u64_stats_update_begin(&s->syncp);
 236         s->rx_packets++;
 237         s->rx_bytes += skb->len;
 238         u64_stats_update_end(&s->syncp);
 239
 240         if (dsa_skb_defer_rx_timestamp(p, skb))
 241                 return 0;
 242
 243         netif_receive_skb(skb);
 244
 245         return 0;
 246 }
 247
 248 #ifdef CONFIG_PM_SLEEP
 249 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 250 {
 251         return dsa_is_user_port(ds, p) && ds->ports[p].slave;
 252 }
 253
 254 int dsa_switch_suspend(struct dsa_switch *ds)
 255 {
 256         int i, ret = 0;
 257
 258         /* Suspend slave network devices */
 259         for (i = 0; i < ds->num_ports; i++) {
 260                 if (!dsa_is_port_initialized(ds, i))
 261                         continue;
 262
 263                 ret = dsa_slave_suspend(ds->ports[i].slave);
 264                 if (ret)
 265                         return ret;
 266         }
 267
 268         if (ds->ops->suspend)
 269                 ret = ds->ops->suspend(ds);
 270
 271         return ret;
 272 }
 273 EXPORT_SYMBOL_GPL(dsa_switch_suspend);
 274
 275 int dsa_switch_resume(struct dsa_switch *ds)
 276 {
 277         int i, ret = 0;
 278
 279         if (ds->ops->resume)
 280                 ret = ds->ops->resume(ds);
 281
 282         if (ret)
 283                 return ret;
 284
 285         /* Resume slave network devices */
 286         for (i = 0; i < ds->num_ports; i++) {
 287                 if (!dsa_is_port_initialized(ds, i))
 288                         continue;
 289
 290                 ret = dsa_slave_resume(ds->ports[i].slave);
 291                 if (ret)
 292                         return ret;
 293         }
 294
 295         return 0;
 296 }
 297 EXPORT_SYMBOL_GPL(dsa_switch_resume);
 298 #endif
 299
 300 static struct packet_type dsa_pack_type __read_mostly = {
 301         .type   = cpu_to_be16(ETH_P_XDSA),
 302         .func   = dsa_switch_rcv,
 303 };
 304
 305 static struct workqueue_struct *dsa_owq;
 306
 307 bool dsa_schedule_work(struct work_struct *work)
 308 {
 309         return queue_work(dsa_owq, work);
 310 }
 311
 312 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);
 313
 314 int register_dsa_notifier(struct notifier_block *nb)
 315 {
 316         return atomic_notifier_chain_register(&dsa_notif_chain, nb);
 317 }
 318 EXPORT_SYMBOL_GPL(register_dsa_notifier);
 319
 320 int unregister_dsa_notifier(struct notifier_block *nb)
 321 {
 322         return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
 323 }
 324 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);
 325
 326 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
 327                        struct dsa_notifier_info *info)
 328 {
 329         info->dev = dev;
 330         return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
 331 }
 332 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
 333
 334 static int __init dsa_init_module(void)
 335 {
 336         int rc;
 337
 338         dsa_owq = alloc_ordered_workqueue("dsa_ordered",
 339                                           WQ_MEM_RECLAIM);
 340         if (!dsa_owq)
 341                 return -ENOMEM;
 342
 343         rc = dsa_slave_register_notifier();
 344         if (rc)
 345                 return rc;
 346
 347         rc = dsa_legacy_register();
 348         if (rc)
 349                 return rc;
 350
 351         dev_add_pack(&dsa_pack_type);
 352
 353         return 0;
 354 }
 355 module_init(dsa_init_module);
 356
 357 static void __exit dsa_cleanup_module(void)
 358 {
 359         dsa_slave_unregister_notifier();
 360         dev_remove_pack(&dsa_pack_type);
 361         dsa_legacy_unregister();
 362         destroy_workqueue(dsa_owq);
 363 }
 364 module_exit(dsa_cleanup_module);
 365
 366 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 367 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 368 MODULE_LICENSE("GPL");
 369 MODULE_ALIAS("platform:dsa");