drivers/usb/gadget/function/u

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This source file includes following definitions.
qlen
eth_get_drvinfo
defer_kevent
rx_submit
rx_complete
prealloc
alloc_requests
rx_fill
eth_work
tx_complete
is_promisc
eth_start_xmit
eth_start
eth_open
eth_stop
get_ether_addr
get_ether_addr_str
gether_setup_name
gether_setup_name_default
gether_register_netdev
gether_set_gadget
gether_set_dev_addr
gether_get_dev_addr
gether_set_host_addr
gether_get_host_addr
gether_get_host_addr_cdc
gether_get_host_addr_u8
gether_set_qmult
gether_get_qmult
gether_get_ifname
gether_cleanup
gether_connect
gether_disconnect
   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
   4  *
   5  * Copyright (C) 2003-2005,2008 David Brownell
   6  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
   7  * Copyright (C) 2008 Nokia Corporation
   8  */
   9 
  10 /* #define VERBOSE_DEBUG */
  11 
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/gfp.h>
  15 #include <linux/device.h>
  16 #include <linux/ctype.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/ethtool.h>
  19 #include <linux/if_vlan.h>
  20 
  21 #include "u_ether.h"
  22 
  23 
  24 /*
  25  * This component encapsulates the Ethernet link glue needed to provide
  26  * one (!) network link through the USB gadget stack, normally "usb0".
  27  *
  28  * The control and data models are handled by the function driver which
  29  * connects to this code; such as CDC Ethernet (ECM or EEM),
  30  * "CDC Subset", or RNDIS.  That includes all descriptor and endpoint
  31  * management.
  32  *
  33  * Link level addressing is handled by this component using module
  34  * parameters; if no such parameters are provided, random link level
  35  * addresses are used.  Each end of the link uses one address.  The
  36  * host end address is exported in various ways, and is often recorded
  37  * in configuration databases.
  38  *
  39  * The driver which assembles each configuration using such a link is
  40  * responsible for ensuring that each configuration includes at most one
  41  * instance of is network link.  (The network layer provides ways for
  42  * this single "physical" link to be used by multiple virtual links.)
  43  */
  44 
  45 #define UETH__VERSION   "29-May-2008"
  46 
  47 /* Experiments show that both Linux and Windows hosts allow up to 16k
  48  * frame sizes. Set the max size to 15k+52 to prevent allocating 32k
  49  * blocks and still have efficient handling. */
  50 #define GETHER_MAX_ETH_FRAME_LEN 15412
  51 
  52 struct eth_dev {
  53         /* lock is held while accessing port_usb
  54          */
  55         spinlock_t              lock;
  56         struct gether           *port_usb;
  57 
  58         struct net_device       *net;
  59         struct usb_gadget       *gadget;
  60 
  61         spinlock_t              req_lock;       /* guard {rx,tx}_reqs */
  62         struct list_head        tx_reqs, rx_reqs;
  63         atomic_t                tx_qlen;
  64 
  65         struct sk_buff_head     rx_frames;
  66 
  67         unsigned                qmult;
  68 
  69         unsigned                header_len;
  70         struct sk_buff          *(*wrap)(struct gether *, struct sk_buff *skb);
  71         int                     (*unwrap)(struct gether *,
  72                                                 struct sk_buff *skb,
  73                                                 struct sk_buff_head *list);
  74 
  75         struct work_struct      work;
  76 
  77         unsigned long           todo;
  78 #define WORK_RX_MEMORY          0
  79 
  80         bool                    zlp;
  81         bool                    no_skb_reserve;
  82         u8                      host_mac[ETH_ALEN];
  83         u8                      dev_mac[ETH_ALEN];
  84 };
  85 
  86 /*-------------------------------------------------------------------------*/
  87 
  88 #define RX_EXTRA        20      /* bytes guarding against rx overflows */
  89 
  90 #define DEFAULT_QLEN    2       /* double buffering by default */
  91 
  92 /* for dual-speed hardware, use deeper queues at high/super speed */
  93 static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
  94 {
  95         if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
  96                                             gadget->speed == USB_SPEED_SUPER))
  97                 return qmult * DEFAULT_QLEN;
  98         else
  99                 return DEFAULT_QLEN;
 100 }
 101 
 102 /*-------------------------------------------------------------------------*/
 103 
 104 /* REVISIT there must be a better way than having two sets
 105  * of debug calls ...
 106  */
 107 
 108 #undef DBG
 109 #undef VDBG
 110 #undef ERROR
 111 #undef INFO
 112 
 113 #define xprintk(d, level, fmt, args...) \
 114         printk(level "%s: " fmt , (d)->net->name , ## args)
 115 
 116 #ifdef DEBUG
 117 #undef DEBUG
 118 #define DBG(dev, fmt, args...) \
 119         xprintk(dev , KERN_DEBUG , fmt , ## args)
 120 #else
 121 #define DBG(dev, fmt, args...) \
 122         do { } while (0)
 123 #endif /* DEBUG */
 124 
 125 #ifdef VERBOSE_DEBUG
 126 #define VDBG    DBG
 127 #else
 128 #define VDBG(dev, fmt, args...) \
 129         do { } while (0)
 130 #endif /* DEBUG */
 131 
 132 #define ERROR(dev, fmt, args...) \
 133         xprintk(dev , KERN_ERR , fmt , ## args)
 134 #define INFO(dev, fmt, args...) \
 135         xprintk(dev , KERN_INFO , fmt , ## args)
 136 
 137 /*-------------------------------------------------------------------------*/
 138 
 139 /* NETWORK DRIVER HOOKUP (to the layer above this driver) */
 140 
 141 static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
 142 {
 143         struct eth_dev *dev = netdev_priv(net);
 144 
 145         strlcpy(p->driver, "g_ether", sizeof(p->driver));
 146         strlcpy(p->version, UETH__VERSION, sizeof(p->version));
 147         strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
 148         strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
 149 }
 150 
 151 /* REVISIT can also support:
 152  *   - WOL (by tracking suspends and issuing remote wakeup)
 153  *   - msglevel (implies updated messaging)
 154  *   - ... probably more ethtool ops
 155  */
 156 
 157 static const struct ethtool_ops ops = {
 158         .get_drvinfo = eth_get_drvinfo,
 159         .get_link = ethtool_op_get_link,
 160 };
 161 
 162 static void defer_kevent(struct eth_dev *dev, int flag)
 163 {
 164         if (test_and_set_bit(flag, &dev->todo))
 165                 return;
 166         if (!schedule_work(&dev->work))
 167                 ERROR(dev, "kevent %d may have been dropped\n", flag);
 168         else
 169                 DBG(dev, "kevent %d scheduled\n", flag);
 170 }
 171 
 172 static void rx_complete(struct usb_ep *ep, struct usb_request *req);
 173 
 174 static int
 175 rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
 176 {
 177         struct usb_gadget *g = dev->gadget;
 178         struct sk_buff  *skb;
 179         int             retval = -ENOMEM;
 180         size_t          size = 0;
 181         struct usb_ep   *out;
 182         unsigned long   flags;
 183 
 184         spin_lock_irqsave(&dev->lock, flags);
 185         if (dev->port_usb)
 186                 out = dev->port_usb->out_ep;
 187         else
 188                 out = NULL;
 189 
 190         if (!out)
 191         {
 192                 spin_unlock_irqrestore(&dev->lock, flags);
 193                 return -ENOTCONN;
 194         }
 195 
 196         /* Padding up to RX_EXTRA handles minor disagreements with host.
 197          * Normally we use the USB "terminate on short read" convention;
 198          * so allow up to (N*maxpacket), since that memory is normally
 199          * already allocated.  Some hardware doesn't deal well with short
 200          * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
 201          * byte off the end (to force hardware errors on overflow).
 202          *
 203          * RNDIS uses internal framing, and explicitly allows senders to
 204          * pad to end-of-packet.  That's potentially nice for speed, but
 205          * means receivers can't recover lost synch on their own (because
 206          * new packets don't only start after a short RX).
 207          */
 208         size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
 209         size += dev->port_usb->header_len;
 210 
 211         if (g->quirk_ep_out_aligned_size) {
 212                 size += out->maxpacket - 1;
 213                 size -= size % out->maxpacket;
 214         }
 215 
 216         if (dev->port_usb->is_fixed)
 217                 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
 218         spin_unlock_irqrestore(&dev->lock, flags);
 219 
 220         skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
 221         if (skb == NULL) {
 222                 DBG(dev, "no rx skb\n");
 223                 goto enomem;
 224         }
 225 
 226         /* Some platforms perform better when IP packets are aligned,
 227          * but on at least one, checksumming fails otherwise.  Note:
 228          * RNDIS headers involve variable numbers of LE32 values.
 229          */
 230         if (likely(!dev->no_skb_reserve))
 231                 skb_reserve(skb, NET_IP_ALIGN);
 232 
 233         req->buf = skb->data;
 234         req->length = size;
 235         req->complete = rx_complete;
 236         req->context = skb;
 237 
 238         retval = usb_ep_queue(out, req, gfp_flags);
 239         if (retval == -ENOMEM)
 240 enomem:
 241                 defer_kevent(dev, WORK_RX_MEMORY);
 242         if (retval) {
 243                 DBG(dev, "rx submit --> %d\n", retval);
 244                 if (skb)
 245                         dev_kfree_skb_any(skb);
 246                 spin_lock_irqsave(&dev->req_lock, flags);
 247                 list_add(&req->list, &dev->rx_reqs);
 248                 spin_unlock_irqrestore(&dev->req_lock, flags);
 249         }
 250         return retval;
 251 }
 252 
 253 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
 254 {
 255         struct sk_buff  *skb = req->context, *skb2;
 256         struct eth_dev  *dev = ep->driver_data;
 257         int             status = req->status;
 258 
 259         switch (status) {
 260 
 261         /* normal completion */
 262         case 0:
 263                 skb_put(skb, req->actual);
 264 
 265                 if (dev->unwrap) {
 266                         unsigned long   flags;
 267 
 268                         spin_lock_irqsave(&dev->lock, flags);
 269                         if (dev->port_usb) {
 270                                 status = dev->unwrap(dev->port_usb,
 271                                                         skb,
 272                                                         &dev->rx_frames);
 273                         } else {
 274                                 dev_kfree_skb_any(skb);
 275                                 status = -ENOTCONN;
 276                         }
 277                         spin_unlock_irqrestore(&dev->lock, flags);
 278                 } else {
 279                         skb_queue_tail(&dev->rx_frames, skb);
 280                 }
 281                 skb = NULL;
 282 
 283                 skb2 = skb_dequeue(&dev->rx_frames);
 284                 while (skb2) {
 285                         if (status < 0
 286                                         || ETH_HLEN > skb2->len
 287                                         || skb2->len > GETHER_MAX_ETH_FRAME_LEN) {
 288                                 dev->net->stats.rx_errors++;
 289                                 dev->net->stats.rx_length_errors++;
 290                                 DBG(dev, "rx length %d\n", skb2->len);
 291                                 dev_kfree_skb_any(skb2);
 292                                 goto next_frame;
 293                         }
 294                         skb2->protocol = eth_type_trans(skb2, dev->net);
 295                         dev->net->stats.rx_packets++;
 296                         dev->net->stats.rx_bytes += skb2->len;
 297 
 298                         /* no buffer copies needed, unless hardware can't
 299                          * use skb buffers.
 300                          */
 301                         status = netif_rx(skb2);
 302 next_frame:
 303                         skb2 = skb_dequeue(&dev->rx_frames);
 304                 }
 305                 break;
 306 
 307         /* software-driven interface shutdown */
 308         case -ECONNRESET:               /* unlink */
 309         case -ESHUTDOWN:                /* disconnect etc */
 310                 VDBG(dev, "rx shutdown, code %d\n", status);
 311                 goto quiesce;
 312 
 313         /* for hardware automagic (such as pxa) */
 314         case -ECONNABORTED:             /* endpoint reset */
 315                 DBG(dev, "rx %s reset\n", ep->name);
 316                 defer_kevent(dev, WORK_RX_MEMORY);
 317 quiesce:
 318                 dev_kfree_skb_any(skb);
 319                 goto clean;
 320 
 321         /* data overrun */
 322         case -EOVERFLOW:
 323                 dev->net->stats.rx_over_errors++;
 324                 /* FALLTHROUGH */
 325 
 326         default:
 327                 dev->net->stats.rx_errors++;
 328                 DBG(dev, "rx status %d\n", status);
 329                 break;
 330         }
 331 
 332         if (skb)
 333                 dev_kfree_skb_any(skb);
 334         if (!netif_running(dev->net)) {
 335 clean:
 336                 spin_lock(&dev->req_lock);
 337                 list_add(&req->list, &dev->rx_reqs);
 338                 spin_unlock(&dev->req_lock);
 339                 req = NULL;
 340         }
 341         if (req)
 342                 rx_submit(dev, req, GFP_ATOMIC);
 343 }
 344 
 345 static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
 346 {
 347         unsigned                i;
 348         struct usb_request      *req;
 349 
 350         if (!n)
 351                 return -ENOMEM;
 352 
 353         /* queue/recycle up to N requests */
 354         i = n;
 355         list_for_each_entry(req, list, list) {
 356                 if (i-- == 0)
 357                         goto extra;
 358         }
 359         while (i--) {
 360                 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 361                 if (!req)
 362                         return list_empty(list) ? -ENOMEM : 0;
 363                 list_add(&req->list, list);
 364         }
 365         return 0;
 366 
 367 extra:
 368         /* free extras */
 369         for (;;) {
 370                 struct list_head        *next;
 371 
 372                 next = req->list.next;
 373                 list_del(&req->list);
 374                 usb_ep_free_request(ep, req);
 375 
 376                 if (next == list)
 377                         break;
 378 
 379                 req = container_of(next, struct usb_request, list);
 380         }
 381         return 0;
 382 }
 383 
 384 static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
 385 {
 386         int     status;
 387 
 388         spin_lock(&dev->req_lock);
 389         status = prealloc(&dev->tx_reqs, link->in_ep, n);
 390         if (status < 0)
 391                 goto fail;
 392         status = prealloc(&dev->rx_reqs, link->out_ep, n);
 393         if (status < 0)
 394                 goto fail;
 395         goto done;
 396 fail:
 397         DBG(dev, "can't alloc requests\n");
 398 done:
 399         spin_unlock(&dev->req_lock);
 400         return status;
 401 }
 402 
 403 static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
 404 {
 405         struct usb_request      *req;
 406         unsigned long           flags;
 407 
 408         /* fill unused rxq slots with some skb */
 409         spin_lock_irqsave(&dev->req_lock, flags);
 410         while (!list_empty(&dev->rx_reqs)) {
 411                 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
 412                 list_del_init(&req->list);
 413                 spin_unlock_irqrestore(&dev->req_lock, flags);
 414 
 415                 if (rx_submit(dev, req, gfp_flags) < 0) {
 416                         defer_kevent(dev, WORK_RX_MEMORY);
 417                         return;
 418                 }
 419 
 420                 spin_lock_irqsave(&dev->req_lock, flags);
 421         }
 422         spin_unlock_irqrestore(&dev->req_lock, flags);
 423 }
 424 
 425 static void eth_work(struct work_struct *work)
 426 {
 427         struct eth_dev  *dev = container_of(work, struct eth_dev, work);
 428 
 429         if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
 430                 if (netif_running(dev->net))
 431                         rx_fill(dev, GFP_KERNEL);
 432         }
 433 
 434         if (dev->todo)
 435                 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
 436 }
 437 
 438 static void tx_complete(struct usb_ep *ep, struct usb_request *req)
 439 {
 440         struct sk_buff  *skb = req->context;
 441         struct eth_dev  *dev = ep->driver_data;
 442 
 443         switch (req->status) {
 444         default:
 445                 dev->net->stats.tx_errors++;
 446                 VDBG(dev, "tx err %d\n", req->status);
 447                 /* FALLTHROUGH */
 448         case -ECONNRESET:               /* unlink */
 449         case -ESHUTDOWN:                /* disconnect etc */
 450                 dev_kfree_skb_any(skb);
 451                 break;
 452         case 0:
 453                 dev->net->stats.tx_bytes += skb->len;
 454                 dev_consume_skb_any(skb);
 455         }
 456         dev->net->stats.tx_packets++;
 457 
 458         spin_lock(&dev->req_lock);
 459         list_add(&req->list, &dev->tx_reqs);
 460         spin_unlock(&dev->req_lock);
 461 
 462         atomic_dec(&dev->tx_qlen);
 463         if (netif_carrier_ok(dev->net))
 464                 netif_wake_queue(dev->net);
 465 }
 466 
 467 static inline int is_promisc(u16 cdc_filter)
 468 {
 469         return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
 470 }
 471 
 472 static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
 473                                         struct net_device *net)
 474 {
 475         struct eth_dev          *dev = netdev_priv(net);
 476         int                     length = 0;
 477         int                     retval;
 478         struct usb_request      *req = NULL;
 479         unsigned long           flags;
 480         struct usb_ep           *in;
 481         u16                     cdc_filter;
 482 
 483         spin_lock_irqsave(&dev->lock, flags);
 484         if (dev->port_usb) {
 485                 in = dev->port_usb->in_ep;
 486                 cdc_filter = dev->port_usb->cdc_filter;
 487         } else {
 488                 in = NULL;
 489                 cdc_filter = 0;
 490         }
 491         spin_unlock_irqrestore(&dev->lock, flags);
 492 
 493         if (skb && !in) {
 494                 dev_kfree_skb_any(skb);
 495                 return NETDEV_TX_OK;
 496         }
 497 
 498         /* apply outgoing CDC or RNDIS filters */
 499         if (skb && !is_promisc(cdc_filter)) {
 500                 u8              *dest = skb->data;
 501 
 502                 if (is_multicast_ether_addr(dest)) {
 503                         u16     type;
 504 
 505                         /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
 506                          * SET_ETHERNET_MULTICAST_FILTERS requests
 507                          */
 508                         if (is_broadcast_ether_addr(dest))
 509                                 type = USB_CDC_PACKET_TYPE_BROADCAST;
 510                         else
 511                                 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
 512                         if (!(cdc_filter & type)) {
 513                                 dev_kfree_skb_any(skb);
 514                                 return NETDEV_TX_OK;
 515                         }
 516                 }
 517                 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
 518         }
 519 
 520         spin_lock_irqsave(&dev->req_lock, flags);
 521         /*
 522          * this freelist can be empty if an interrupt triggered disconnect()
 523          * and reconfigured the gadget (shutting down this queue) after the
 524          * network stack decided to xmit but before we got the spinlock.
 525          */
 526         if (list_empty(&dev->tx_reqs)) {
 527                 spin_unlock_irqrestore(&dev->req_lock, flags);
 528                 return NETDEV_TX_BUSY;
 529         }
 530 
 531         req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
 532         list_del(&req->list);
 533 
 534         /* temporarily stop TX queue when the freelist empties */
 535         if (list_empty(&dev->tx_reqs))
 536                 netif_stop_queue(net);
 537         spin_unlock_irqrestore(&dev->req_lock, flags);
 538 
 539         /* no buffer copies needed, unless the network stack did it
 540          * or the hardware can't use skb buffers.
 541          * or there's not enough space for extra headers we need
 542          */
 543         if (dev->wrap) {
 544                 unsigned long   flags;
 545 
 546                 spin_lock_irqsave(&dev->lock, flags);
 547                 if (dev->port_usb)
 548                         skb = dev->wrap(dev->port_usb, skb);
 549                 spin_unlock_irqrestore(&dev->lock, flags);
 550                 if (!skb) {
 551                         /* Multi frame CDC protocols may store the frame for
 552                          * later which is not a dropped frame.
 553                          */
 554                         if (dev->port_usb &&
 555                                         dev->port_usb->supports_multi_frame)
 556                                 goto multiframe;
 557                         goto drop;
 558                 }
 559         }
 560 
 561         length = skb->len;
 562         req->buf = skb->data;
 563         req->context = skb;
 564         req->complete = tx_complete;
 565 
 566         /* NCM requires no zlp if transfer is dwNtbInMaxSize */
 567         if (dev->port_usb &&
 568             dev->port_usb->is_fixed &&
 569             length == dev->port_usb->fixed_in_len &&
 570             (length % in->maxpacket) == 0)
 571                 req->zero = 0;
 572         else
 573                 req->zero = 1;
 574 
 575         /* use zlp framing on tx for strict CDC-Ether conformance,
 576          * though any robust network rx path ignores extra padding.
 577          * and some hardware doesn't like to write zlps.
 578          */
 579         if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
 580                 length++;
 581 
 582         req->length = length;
 583 
 584         retval = usb_ep_queue(in, req, GFP_ATOMIC);
 585         switch (retval) {
 586         default:
 587                 DBG(dev, "tx queue err %d\n", retval);
 588                 break;
 589         case 0:
 590                 netif_trans_update(net);
 591                 atomic_inc(&dev->tx_qlen);
 592         }
 593 
 594         if (retval) {
 595                 dev_kfree_skb_any(skb);
 596 drop:
 597                 dev->net->stats.tx_dropped++;
 598 multiframe:
 599                 spin_lock_irqsave(&dev->req_lock, flags);
 600                 if (list_empty(&dev->tx_reqs))
 601                         netif_start_queue(net);
 602                 list_add(&req->list, &dev->tx_reqs);
 603                 spin_unlock_irqrestore(&dev->req_lock, flags);
 604         }
 605         return NETDEV_TX_OK;
 606 }
 607 
 608 /*-------------------------------------------------------------------------*/
 609 
 610 static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
 611 {
 612         DBG(dev, "%s\n", __func__);
 613 
 614         /* fill the rx queue */
 615         rx_fill(dev, gfp_flags);
 616 
 617         /* and open the tx floodgates */
 618         atomic_set(&dev->tx_qlen, 0);
 619         netif_wake_queue(dev->net);
 620 }
 621 
 622 static int eth_open(struct net_device *net)
 623 {
 624         struct eth_dev  *dev = netdev_priv(net);
 625         struct gether   *link;
 626 
 627         DBG(dev, "%s\n", __func__);
 628         if (netif_carrier_ok(dev->net))
 629                 eth_start(dev, GFP_KERNEL);
 630 
 631         spin_lock_irq(&dev->lock);
 632         link = dev->port_usb;
 633         if (link && link->open)
 634                 link->open(link);
 635         spin_unlock_irq(&dev->lock);
 636 
 637         return 0;
 638 }
 639 
 640 static int eth_stop(struct net_device *net)
 641 {
 642         struct eth_dev  *dev = netdev_priv(net);
 643         unsigned long   flags;
 644 
 645         VDBG(dev, "%s\n", __func__);
 646         netif_stop_queue(net);
 647 
 648         DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
 649                 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
 650                 dev->net->stats.rx_errors, dev->net->stats.tx_errors
 651                 );
 652 
 653         /* ensure there are no more active requests */
 654         spin_lock_irqsave(&dev->lock, flags);
 655         if (dev->port_usb) {
 656                 struct gether   *link = dev->port_usb;
 657                 const struct usb_endpoint_descriptor *in;
 658                 const struct usb_endpoint_descriptor *out;
 659 
 660                 if (link->close)
 661                         link->close(link);
 662 
 663                 /* NOTE:  we have no abort-queue primitive we could use
 664                  * to cancel all pending I/O.  Instead, we disable then
 665                  * reenable the endpoints ... this idiom may leave toggle
 666                  * wrong, but that's a self-correcting error.
 667                  *
 668                  * REVISIT:  we *COULD* just let the transfers complete at
 669                  * their own pace; the network stack can handle old packets.
 670                  * For the moment we leave this here, since it works.
 671                  */
 672                 in = link->in_ep->desc;
 673                 out = link->out_ep->desc;
 674                 usb_ep_disable(link->in_ep);
 675                 usb_ep_disable(link->out_ep);
 676                 if (netif_carrier_ok(net)) {
 677                         DBG(dev, "host still using in/out endpoints\n");
 678                         link->in_ep->desc = in;
 679                         link->out_ep->desc = out;
 680                         usb_ep_enable(link->in_ep);
 681                         usb_ep_enable(link->out_ep);
 682                 }
 683         }
 684         spin_unlock_irqrestore(&dev->lock, flags);
 685 
 686         return 0;
 687 }
 688 
 689 /*-------------------------------------------------------------------------*/
 690 
 691 static int get_ether_addr(const char *str, u8 *dev_addr)
 692 {
 693         if (str) {
 694                 unsigned        i;
 695 
 696                 for (i = 0; i < 6; i++) {
 697                         unsigned char num;
 698 
 699                         if ((*str == '.') || (*str == ':'))
 700                                 str++;
 701                         num = hex_to_bin(*str++) << 4;
 702                         num |= hex_to_bin(*str++);
 703                         dev_addr [i] = num;
 704                 }
 705                 if (is_valid_ether_addr(dev_addr))
 706                         return 0;
 707         }
 708         eth_random_addr(dev_addr);
 709         return 1;
 710 }
 711 
 712 static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
 713 {
 714         if (len < 18)
 715                 return -EINVAL;
 716 
 717         snprintf(str, len, "%pM", dev_addr);
 718         return 18;
 719 }
 720 
 721 static const struct net_device_ops eth_netdev_ops = {
 722         .ndo_open               = eth_open,
 723         .ndo_stop               = eth_stop,
 724         .ndo_start_xmit         = eth_start_xmit,
 725         .ndo_set_mac_address    = eth_mac_addr,
 726         .ndo_validate_addr      = eth_validate_addr,
 727 };
 728 
 729 static struct device_type gadget_type = {
 730         .name   = "gadget",
 731 };
 732 
 733 /**
 734  * gether_setup_name - initialize one ethernet-over-usb link
 735  * @g: gadget to associated with these links
 736  * @ethaddr: NULL, or a buffer in which the ethernet address of the
 737  *      host side of the link is recorded
 738  * @netname: name for network device (for example, "usb")
 739  * Context: may sleep
 740  *
 741  * This sets up the single network link that may be exported by a
 742  * gadget driver using this framework.  The link layer addresses are
 743  * set up using module parameters.
 744  *
 745  * Returns an eth_dev pointer on success, or an ERR_PTR on failure.
 746  */
 747 struct eth_dev *gether_setup_name(struct usb_gadget *g,
 748                 const char *dev_addr, const char *host_addr,
 749                 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname)
 750 {
 751         struct eth_dev          *dev;
 752         struct net_device       *net;
 753         int                     status;
 754 
 755         net = alloc_etherdev(sizeof *dev);
 756         if (!net)
 757                 return ERR_PTR(-ENOMEM);
 758 
 759         dev = netdev_priv(net);
 760         spin_lock_init(&dev->lock);
 761         spin_lock_init(&dev->req_lock);
 762         INIT_WORK(&dev->work, eth_work);
 763         INIT_LIST_HEAD(&dev->tx_reqs);
 764         INIT_LIST_HEAD(&dev->rx_reqs);
 765 
 766         skb_queue_head_init(&dev->rx_frames);
 767 
 768         /* network device setup */
 769         dev->net = net;
 770         dev->qmult = qmult;
 771         snprintf(net->name, sizeof(net->name), "%s%%d", netname);
 772 
 773         if (get_ether_addr(dev_addr, net->dev_addr))
 774                 dev_warn(&g->dev,
 775                         "using random %s ethernet address\n", "self");
 776         if (get_ether_addr(host_addr, dev->host_mac))
 777                 dev_warn(&g->dev,
 778                         "using random %s ethernet address\n", "host");
 779 
 780         if (ethaddr)
 781                 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
 782 
 783         net->netdev_ops = &eth_netdev_ops;
 784 
 785         net->ethtool_ops = &ops;
 786 
 787         /* MTU range: 14 - 15412 */
 788         net->min_mtu = ETH_HLEN;
 789         net->max_mtu = GETHER_MAX_ETH_FRAME_LEN;
 790 
 791         dev->gadget = g;
 792         SET_NETDEV_DEV(net, &g->dev);
 793         SET_NETDEV_DEVTYPE(net, &gadget_type);
 794 
 795         status = register_netdev(net);
 796         if (status < 0) {
 797                 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
 798                 free_netdev(net);
 799                 dev = ERR_PTR(status);
 800         } else {
 801                 INFO(dev, "MAC %pM\n", net->dev_addr);
 802                 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
 803 
 804                 /*
 805                  * two kinds of host-initiated state changes:
 806                  *  - iff DATA transfer is active, carrier is "on"
 807                  *  - tx queueing enabled if open *and* carrier is "on"
 808                  */
 809                 netif_carrier_off(net);
 810         }
 811 
 812         return dev;
 813 }
 814 EXPORT_SYMBOL_GPL(gether_setup_name);
 815 
 816 struct net_device *gether_setup_name_default(const char *netname)
 817 {
 818         struct net_device       *net;
 819         struct eth_dev          *dev;
 820 
 821         net = alloc_etherdev(sizeof(*dev));
 822         if (!net)
 823                 return ERR_PTR(-ENOMEM);
 824 
 825         dev = netdev_priv(net);
 826         spin_lock_init(&dev->lock);
 827         spin_lock_init(&dev->req_lock);
 828         INIT_WORK(&dev->work, eth_work);
 829         INIT_LIST_HEAD(&dev->tx_reqs);
 830         INIT_LIST_HEAD(&dev->rx_reqs);
 831 
 832         skb_queue_head_init(&dev->rx_frames);
 833 
 834         /* network device setup */
 835         dev->net = net;
 836         dev->qmult = QMULT_DEFAULT;
 837         snprintf(net->name, sizeof(net->name), "%s%%d", netname);
 838 
 839         eth_random_addr(dev->dev_mac);
 840         pr_warn("using random %s ethernet address\n", "self");
 841         eth_random_addr(dev->host_mac);
 842         pr_warn("using random %s ethernet address\n", "host");
 843 
 844         net->netdev_ops = &eth_netdev_ops;
 845 
 846         net->ethtool_ops = &ops;
 847         SET_NETDEV_DEVTYPE(net, &gadget_type);
 848 
 849         /* MTU range: 14 - 15412 */
 850         net->min_mtu = ETH_HLEN;
 851         net->max_mtu = GETHER_MAX_ETH_FRAME_LEN;
 852 
 853         return net;
 854 }
 855 EXPORT_SYMBOL_GPL(gether_setup_name_default);
 856 
 857 int gether_register_netdev(struct net_device *net)
 858 {
 859         struct eth_dev *dev;
 860         struct usb_gadget *g;
 861         struct sockaddr sa;
 862         int status;
 863 
 864         if (!net->dev.parent)
 865                 return -EINVAL;
 866         dev = netdev_priv(net);
 867         g = dev->gadget;
 868         status = register_netdev(net);
 869         if (status < 0) {
 870                 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
 871                 return status;
 872         } else {
 873                 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
 874 
 875                 /* two kinds of host-initiated state changes:
 876                  *  - iff DATA transfer is active, carrier is "on"
 877                  *  - tx queueing enabled if open *and* carrier is "on"
 878                  */
 879                 netif_carrier_off(net);
 880         }
 881         sa.sa_family = net->type;
 882         memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
 883         rtnl_lock();
 884         status = dev_set_mac_address(net, &sa, NULL);
 885         rtnl_unlock();
 886         if (status)
 887                 pr_warn("cannot set self ethernet address: %d\n", status);
 888         else
 889                 INFO(dev, "MAC %pM\n", dev->dev_mac);
 890 
 891         return status;
 892 }
 893 EXPORT_SYMBOL_GPL(gether_register_netdev);
 894 
 895 void gether_set_gadget(struct net_device *net, struct usb_gadget *g)
 896 {
 897         struct eth_dev *dev;
 898 
 899         dev = netdev_priv(net);
 900         dev->gadget = g;
 901         SET_NETDEV_DEV(net, &g->dev);
 902 }
 903 EXPORT_SYMBOL_GPL(gether_set_gadget);
 904 
 905 int gether_set_dev_addr(struct net_device *net, const char *dev_addr)
 906 {
 907         struct eth_dev *dev;
 908         u8 new_addr[ETH_ALEN];
 909 
 910         dev = netdev_priv(net);
 911         if (get_ether_addr(dev_addr, new_addr))
 912                 return -EINVAL;
 913         memcpy(dev->dev_mac, new_addr, ETH_ALEN);
 914         return 0;
 915 }
 916 EXPORT_SYMBOL_GPL(gether_set_dev_addr);
 917 
 918 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len)
 919 {
 920         struct eth_dev *dev;
 921         int ret;
 922 
 923         dev = netdev_priv(net);
 924         ret = get_ether_addr_str(dev->dev_mac, dev_addr, len);
 925         if (ret + 1 < len) {
 926                 dev_addr[ret++] = '\n';
 927                 dev_addr[ret] = '\0';
 928         }
 929 
 930         return ret;
 931 }
 932 EXPORT_SYMBOL_GPL(gether_get_dev_addr);
 933 
 934 int gether_set_host_addr(struct net_device *net, const char *host_addr)
 935 {
 936         struct eth_dev *dev;
 937         u8 new_addr[ETH_ALEN];
 938 
 939         dev = netdev_priv(net);
 940         if (get_ether_addr(host_addr, new_addr))
 941                 return -EINVAL;
 942         memcpy(dev->host_mac, new_addr, ETH_ALEN);
 943         return 0;
 944 }
 945 EXPORT_SYMBOL_GPL(gether_set_host_addr);
 946 
 947 int gether_get_host_addr(struct net_device *net, char *host_addr, int len)
 948 {
 949         struct eth_dev *dev;
 950         int ret;
 951 
 952         dev = netdev_priv(net);
 953         ret = get_ether_addr_str(dev->host_mac, host_addr, len);
 954         if (ret + 1 < len) {
 955                 host_addr[ret++] = '\n';
 956                 host_addr[ret] = '\0';
 957         }
 958 
 959         return ret;
 960 }
 961 EXPORT_SYMBOL_GPL(gether_get_host_addr);
 962 
 963 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len)
 964 {
 965         struct eth_dev *dev;
 966 
 967         if (len < 13)
 968                 return -EINVAL;
 969 
 970         dev = netdev_priv(net);
 971         snprintf(host_addr, len, "%pm", dev->host_mac);
 972 
 973         return strlen(host_addr);
 974 }
 975 EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);
 976 
 977 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN])
 978 {
 979         struct eth_dev *dev;
 980 
 981         dev = netdev_priv(net);
 982         memcpy(host_mac, dev->host_mac, ETH_ALEN);
 983 }
 984 EXPORT_SYMBOL_GPL(gether_get_host_addr_u8);
 985 
 986 void gether_set_qmult(struct net_device *net, unsigned qmult)
 987 {
 988         struct eth_dev *dev;
 989 
 990         dev = netdev_priv(net);
 991         dev->qmult = qmult;
 992 }
 993 EXPORT_SYMBOL_GPL(gether_set_qmult);
 994 
 995 unsigned gether_get_qmult(struct net_device *net)
 996 {
 997         struct eth_dev *dev;
 998 
 999         dev = netdev_priv(net);
1000         return dev->qmult;
1001 }
1002 EXPORT_SYMBOL_GPL(gether_get_qmult);
1003 
1004 int gether_get_ifname(struct net_device *net, char *name, int len)
1005 {
1006         int ret;
1007 
1008         rtnl_lock();
1009         ret = scnprintf(name, len, "%s\n", netdev_name(net));
1010         rtnl_unlock();
1011         return ret;
1012 }
1013 EXPORT_SYMBOL_GPL(gether_get_ifname);
1014 
1015 /**
1016  * gether_cleanup - remove Ethernet-over-USB device
1017  * Context: may sleep
1018  *
1019  * This is called to free all resources allocated by @gether_setup().
1020  */
1021 void gether_cleanup(struct eth_dev *dev)
1022 {
1023         if (!dev)
1024                 return;
1025 
1026         unregister_netdev(dev->net);
1027         flush_work(&dev->work);
1028         free_netdev(dev->net);
1029 }
1030 EXPORT_SYMBOL_GPL(gether_cleanup);
1031 
1032 /**
1033  * gether_connect - notify network layer that USB link is active
1034  * @link: the USB link, set up with endpoints, descriptors matching
1035  *      current device speed, and any framing wrapper(s) set up.
1036  * Context: irqs blocked
1037  *
1038  * This is called to activate endpoints and let the network layer know
1039  * the connection is active ("carrier detect").  It may cause the I/O
1040  * queues to open and start letting network packets flow, but will in
1041  * any case activate the endpoints so that they respond properly to the
1042  * USB host.
1043  *
1044  * Verify net_device pointer returned using IS_ERR().  If it doesn't
1045  * indicate some error code (negative errno), ep->driver_data values
1046  * have been overwritten.
1047  */
1048 struct net_device *gether_connect(struct gether *link)
1049 {
1050         struct eth_dev          *dev = link->ioport;
1051         int                     result = 0;
1052 
1053         if (!dev)
1054                 return ERR_PTR(-EINVAL);
1055 
1056         link->in_ep->driver_data = dev;
1057         result = usb_ep_enable(link->in_ep);
1058         if (result != 0) {
1059                 DBG(dev, "enable %s --> %d\n",
1060                         link->in_ep->name, result);
1061                 goto fail0;
1062         }
1063 
1064         link->out_ep->driver_data = dev;
1065         result = usb_ep_enable(link->out_ep);
1066         if (result != 0) {
1067                 DBG(dev, "enable %s --> %d\n",
1068                         link->out_ep->name, result);
1069                 goto fail1;
1070         }
1071 
1072         if (result == 0)
1073                 result = alloc_requests(dev, link, qlen(dev->gadget,
1074                                         dev->qmult));
1075 
1076         if (result == 0) {
1077                 dev->zlp = link->is_zlp_ok;
1078                 dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
1079                 DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
1080 
1081                 dev->header_len = link->header_len;
1082                 dev->unwrap = link->unwrap;
1083                 dev->wrap = link->wrap;
1084 
1085                 spin_lock(&dev->lock);
1086                 dev->port_usb = link;
1087                 if (netif_running(dev->net)) {
1088                         if (link->open)
1089                                 link->open(link);
1090                 } else {
1091                         if (link->close)
1092                                 link->close(link);
1093                 }
1094                 spin_unlock(&dev->lock);
1095 
1096                 netif_carrier_on(dev->net);
1097                 if (netif_running(dev->net))
1098                         eth_start(dev, GFP_ATOMIC);
1099 
1100         /* on error, disable any endpoints  */
1101         } else {
1102                 (void) usb_ep_disable(link->out_ep);
1103 fail1:
1104                 (void) usb_ep_disable(link->in_ep);
1105         }
1106 fail0:
1107         /* caller is responsible for cleanup on error */
1108         if (result < 0)
1109                 return ERR_PTR(result);
1110         return dev->net;
1111 }
1112 EXPORT_SYMBOL_GPL(gether_connect);
1113 
1114 /**
1115  * gether_disconnect - notify network layer that USB link is inactive
1116  * @link: the USB link, on which gether_connect() was called
1117  * Context: irqs blocked
1118  *
1119  * This is called to deactivate endpoints and let the network layer know
1120  * the connection went inactive ("no carrier").
1121  *
1122  * On return, the state is as if gether_connect() had never been called.
1123  * The endpoints are inactive, and accordingly without active USB I/O.
1124  * Pointers to endpoint descriptors and endpoint private data are nulled.
1125  */
1126 void gether_disconnect(struct gether *link)
1127 {
1128         struct eth_dev          *dev = link->ioport;
1129         struct usb_request      *req;
1130 
1131         WARN_ON(!dev);
1132         if (!dev)
1133                 return;
1134 
1135         DBG(dev, "%s\n", __func__);
1136 
1137         netif_stop_queue(dev->net);
1138         netif_carrier_off(dev->net);
1139 
1140         /* disable endpoints, forcing (synchronous) completion
1141          * of all pending i/o.  then free the request objects
1142          * and forget about the endpoints.
1143          */
1144         usb_ep_disable(link->in_ep);
1145         spin_lock(&dev->req_lock);
1146         while (!list_empty(&dev->tx_reqs)) {
1147                 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
1148                 list_del(&req->list);
1149 
1150                 spin_unlock(&dev->req_lock);
1151                 usb_ep_free_request(link->in_ep, req);
1152                 spin_lock(&dev->req_lock);
1153         }
1154         spin_unlock(&dev->req_lock);
1155         link->in_ep->desc = NULL;
1156 
1157         usb_ep_disable(link->out_ep);
1158         spin_lock(&dev->req_lock);
1159         while (!list_empty(&dev->rx_reqs)) {
1160                 req = list_first_entry(&dev->rx_reqs, struct usb_request, list);
1161                 list_del(&req->list);
1162 
1163                 spin_unlock(&dev->req_lock);
1164                 usb_ep_free_request(link->out_ep, req);
1165                 spin_lock(&dev->req_lock);
1166         }
1167         spin_unlock(&dev->req_lock);
1168         link->out_ep->desc = NULL;
1169 
1170         /* finish forgetting about this USB link episode */
1171         dev->header_len = 0;
1172         dev->unwrap = NULL;
1173         dev->wrap = NULL;
1174 
1175         spin_lock(&dev->lock);
1176         dev->port_usb = NULL;
1177         spin_unlock(&dev->lock);
1178 }
1179 EXPORT_SYMBOL_GPL(gether_disconnect);
1180 
1181 MODULE_LICENSE("GPL");
1182 MODULE_AUTHOR("David Brownell");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/usb/gadget/function/u_ether.c

DEFINITIONS
