David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 1 | /* |
| 2 | * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack |
| 3 | * |
| 4 | * Copyright (C) 2003-2005,2008 David Brownell |
| 5 | * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger |
| 6 | * Copyright (C) 2008 Nokia Corporation |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | */ |
| 22 | |
| 23 | /* #define VERBOSE_DEBUG */ |
| 24 | |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/utsname.h> |
| 27 | #include <linux/device.h> |
| 28 | #include <linux/ctype.h> |
| 29 | #include <linux/etherdevice.h> |
| 30 | #include <linux/ethtool.h> |
| 31 | |
| 32 | #include "u_ether.h" |
| 33 | |
| 34 | |
| 35 | /* |
| 36 | * This component encapsulates the Ethernet link glue needed to provide |
| 37 | * one (!) network link through the USB gadget stack, normally "usb0". |
| 38 | * |
| 39 | * The control and data models are handled by the function driver which |
| 40 | * connects to this code; such as CDC Ethernet, "CDC Subset", or RNDIS. |
| 41 | * That includes all descriptor and endpoint management. |
| 42 | * |
| 43 | * Link level addressing is handled by this component using module |
| 44 | * parameters; if no such parameters are provided, random link level |
| 45 | * addresses are used. Each end of the link uses one address. The |
| 46 | * host end address is exported in various ways, and is often recorded |
| 47 | * in configuration databases. |
| 48 | * |
| 49 | * The driver which assembles each configuration using such a link is |
| 50 | * responsible for ensuring that each configuration includes at most one |
| 51 | * instance of is network link. (The network layer provides ways for |
| 52 | * this single "physical" link to be used by multiple virtual links.) |
| 53 | */ |
| 54 | |
David Brownell | 8a1ce2c | 2008-08-18 17:43:56 -0700 | [diff] [blame] | 55 | #define UETH__VERSION "29-May-2008" |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 56 | |
| 57 | struct eth_dev { |
| 58 | /* lock is held while accessing port_usb |
| 59 | * or updating its backlink port_usb->ioport |
| 60 | */ |
| 61 | spinlock_t lock; |
| 62 | struct gether *port_usb; |
| 63 | |
| 64 | struct net_device *net; |
| 65 | struct usb_gadget *gadget; |
| 66 | |
| 67 | spinlock_t req_lock; /* guard {rx,tx}_reqs */ |
| 68 | struct list_head tx_reqs, rx_reqs; |
| 69 | atomic_t tx_qlen; |
| 70 | |
| 71 | unsigned header_len; |
| 72 | struct sk_buff *(*wrap)(struct sk_buff *skb); |
| 73 | int (*unwrap)(struct sk_buff *skb); |
| 74 | |
| 75 | struct work_struct work; |
| 76 | |
| 77 | unsigned long todo; |
| 78 | #define WORK_RX_MEMORY 0 |
| 79 | |
| 80 | bool zlp; |
| 81 | u8 host_mac[ETH_ALEN]; |
| 82 | }; |
| 83 | |
| 84 | /*-------------------------------------------------------------------------*/ |
| 85 | |
| 86 | #define RX_EXTRA 20 /* bytes guarding against rx overflows */ |
| 87 | |
| 88 | #define DEFAULT_QLEN 2 /* double buffering by default */ |
| 89 | |
| 90 | |
| 91 | #ifdef CONFIG_USB_GADGET_DUALSPEED |
| 92 | |
| 93 | static unsigned qmult = 5; |
| 94 | module_param(qmult, uint, S_IRUGO|S_IWUSR); |
| 95 | MODULE_PARM_DESC(qmult, "queue length multiplier at high speed"); |
| 96 | |
| 97 | #else /* full speed (low speed doesn't do bulk) */ |
| 98 | #define qmult 1 |
| 99 | #endif |
| 100 | |
| 101 | /* for dual-speed hardware, use deeper queues at highspeed */ |
| 102 | static inline int qlen(struct usb_gadget *gadget) |
| 103 | { |
| 104 | if (gadget_is_dualspeed(gadget) && gadget->speed == USB_SPEED_HIGH) |
| 105 | return qmult * DEFAULT_QLEN; |
| 106 | else |
| 107 | return DEFAULT_QLEN; |
| 108 | } |
| 109 | |
| 110 | /*-------------------------------------------------------------------------*/ |
| 111 | |
| 112 | /* REVISIT there must be a better way than having two sets |
| 113 | * of debug calls ... |
| 114 | */ |
| 115 | |
| 116 | #undef DBG |
| 117 | #undef VDBG |
| 118 | #undef ERROR |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 119 | #undef INFO |
| 120 | |
| 121 | #define xprintk(d, level, fmt, args...) \ |
| 122 | printk(level "%s: " fmt , (d)->net->name , ## args) |
| 123 | |
| 124 | #ifdef DEBUG |
| 125 | #undef DEBUG |
| 126 | #define DBG(dev, fmt, args...) \ |
| 127 | xprintk(dev , KERN_DEBUG , fmt , ## args) |
| 128 | #else |
| 129 | #define DBG(dev, fmt, args...) \ |
| 130 | do { } while (0) |
| 131 | #endif /* DEBUG */ |
| 132 | |
| 133 | #ifdef VERBOSE_DEBUG |
| 134 | #define VDBG DBG |
| 135 | #else |
| 136 | #define VDBG(dev, fmt, args...) \ |
| 137 | do { } while (0) |
| 138 | #endif /* DEBUG */ |
| 139 | |
| 140 | #define ERROR(dev, fmt, args...) \ |
| 141 | xprintk(dev , KERN_ERR , fmt , ## args) |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 142 | #define INFO(dev, fmt, args...) \ |
| 143 | xprintk(dev , KERN_INFO , fmt , ## args) |
| 144 | |
| 145 | /*-------------------------------------------------------------------------*/ |
| 146 | |
| 147 | /* NETWORK DRIVER HOOKUP (to the layer above this driver) */ |
| 148 | |
Stephen Hemminger | ccad637 | 2008-11-19 22:42:31 -0800 | [diff] [blame] | 149 | static int ueth_change_mtu(struct net_device *net, int new_mtu) |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 150 | { |
| 151 | struct eth_dev *dev = netdev_priv(net); |
| 152 | unsigned long flags; |
| 153 | int status = 0; |
| 154 | |
| 155 | /* don't change MTU on "live" link (peer won't know) */ |
| 156 | spin_lock_irqsave(&dev->lock, flags); |
| 157 | if (dev->port_usb) |
| 158 | status = -EBUSY; |
| 159 | else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN) |
| 160 | status = -ERANGE; |
| 161 | else |
| 162 | net->mtu = new_mtu; |
| 163 | spin_unlock_irqrestore(&dev->lock, flags); |
| 164 | |
| 165 | return status; |
| 166 | } |
| 167 | |
| 168 | static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p) |
| 169 | { |
| 170 | struct eth_dev *dev = netdev_priv(net); |
| 171 | |
| 172 | strlcpy(p->driver, "g_ether", sizeof p->driver); |
David Brownell | 8a1ce2c | 2008-08-18 17:43:56 -0700 | [diff] [blame] | 173 | strlcpy(p->version, UETH__VERSION, sizeof p->version); |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 174 | strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version); |
| 175 | strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info); |
| 176 | } |
| 177 | |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 178 | /* REVISIT can also support: |
| 179 | * - WOL (by tracking suspends and issuing remote wakeup) |
| 180 | * - msglevel (implies updated messaging) |
| 181 | * - ... probably more ethtool ops |
| 182 | */ |
| 183 | |
Stephen Hemminger | 0fc0b73 | 2009-09-02 01:03:33 -0700 | [diff] [blame^] | 184 | static const struct ethtool_ops ops = { |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 185 | .get_drvinfo = eth_get_drvinfo, |
Jonathan McDowell | 237e75b | 2009-03-26 00:45:27 -0700 | [diff] [blame] | 186 | .get_link = ethtool_op_get_link, |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 187 | }; |
| 188 | |
| 189 | static void defer_kevent(struct eth_dev *dev, int flag) |
| 190 | { |
| 191 | if (test_and_set_bit(flag, &dev->todo)) |
| 192 | return; |
| 193 | if (!schedule_work(&dev->work)) |
| 194 | ERROR(dev, "kevent %d may have been dropped\n", flag); |
| 195 | else |
| 196 | DBG(dev, "kevent %d scheduled\n", flag); |
| 197 | } |
| 198 | |
| 199 | static void rx_complete(struct usb_ep *ep, struct usb_request *req); |
| 200 | |
| 201 | static int |
| 202 | rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags) |
| 203 | { |
| 204 | struct sk_buff *skb; |
| 205 | int retval = -ENOMEM; |
| 206 | size_t size = 0; |
| 207 | struct usb_ep *out; |
| 208 | unsigned long flags; |
| 209 | |
| 210 | spin_lock_irqsave(&dev->lock, flags); |
| 211 | if (dev->port_usb) |
| 212 | out = dev->port_usb->out_ep; |
| 213 | else |
| 214 | out = NULL; |
| 215 | spin_unlock_irqrestore(&dev->lock, flags); |
| 216 | |
| 217 | if (!out) |
| 218 | return -ENOTCONN; |
| 219 | |
| 220 | |
| 221 | /* Padding up to RX_EXTRA handles minor disagreements with host. |
| 222 | * Normally we use the USB "terminate on short read" convention; |
| 223 | * so allow up to (N*maxpacket), since that memory is normally |
| 224 | * already allocated. Some hardware doesn't deal well with short |
| 225 | * reads (e.g. DMA must be N*maxpacket), so for now don't trim a |
| 226 | * byte off the end (to force hardware errors on overflow). |
| 227 | * |
| 228 | * RNDIS uses internal framing, and explicitly allows senders to |
| 229 | * pad to end-of-packet. That's potentially nice for speed, but |
| 230 | * means receivers can't recover lost synch on their own (because |
| 231 | * new packets don't only start after a short RX). |
| 232 | */ |
| 233 | size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA; |
| 234 | size += dev->port_usb->header_len; |
| 235 | size += out->maxpacket - 1; |
| 236 | size -= size % out->maxpacket; |
| 237 | |
| 238 | skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags); |
| 239 | if (skb == NULL) { |
| 240 | DBG(dev, "no rx skb\n"); |
| 241 | goto enomem; |
| 242 | } |
| 243 | |
| 244 | /* Some platforms perform better when IP packets are aligned, |
| 245 | * but on at least one, checksumming fails otherwise. Note: |
| 246 | * RNDIS headers involve variable numbers of LE32 values. |
| 247 | */ |
| 248 | skb_reserve(skb, NET_IP_ALIGN); |
| 249 | |
| 250 | req->buf = skb->data; |
| 251 | req->length = size; |
| 252 | req->complete = rx_complete; |
| 253 | req->context = skb; |
| 254 | |
| 255 | retval = usb_ep_queue(out, req, gfp_flags); |
| 256 | if (retval == -ENOMEM) |
| 257 | enomem: |
| 258 | defer_kevent(dev, WORK_RX_MEMORY); |
| 259 | if (retval) { |
| 260 | DBG(dev, "rx submit --> %d\n", retval); |
| 261 | if (skb) |
| 262 | dev_kfree_skb_any(skb); |
| 263 | spin_lock_irqsave(&dev->req_lock, flags); |
| 264 | list_add(&req->list, &dev->rx_reqs); |
| 265 | spin_unlock_irqrestore(&dev->req_lock, flags); |
| 266 | } |
| 267 | return retval; |
| 268 | } |
| 269 | |
| 270 | static void rx_complete(struct usb_ep *ep, struct usb_request *req) |
| 271 | { |
| 272 | struct sk_buff *skb = req->context; |
| 273 | struct eth_dev *dev = ep->driver_data; |
| 274 | int status = req->status; |
| 275 | |
| 276 | switch (status) { |
| 277 | |
| 278 | /* normal completion */ |
| 279 | case 0: |
| 280 | skb_put(skb, req->actual); |
| 281 | if (dev->unwrap) |
| 282 | status = dev->unwrap(skb); |
| 283 | if (status < 0 |
| 284 | || ETH_HLEN > skb->len |
| 285 | || skb->len > ETH_FRAME_LEN) { |
| 286 | dev->net->stats.rx_errors++; |
| 287 | dev->net->stats.rx_length_errors++; |
| 288 | DBG(dev, "rx length %d\n", skb->len); |
| 289 | break; |
| 290 | } |
| 291 | |
| 292 | skb->protocol = eth_type_trans(skb, dev->net); |
| 293 | dev->net->stats.rx_packets++; |
| 294 | dev->net->stats.rx_bytes += skb->len; |
| 295 | |
| 296 | /* no buffer copies needed, unless hardware can't |
| 297 | * use skb buffers. |
| 298 | */ |
| 299 | status = netif_rx(skb); |
| 300 | skb = NULL; |
| 301 | break; |
| 302 | |
| 303 | /* software-driven interface shutdown */ |
| 304 | case -ECONNRESET: /* unlink */ |
| 305 | case -ESHUTDOWN: /* disconnect etc */ |
| 306 | VDBG(dev, "rx shutdown, code %d\n", status); |
| 307 | goto quiesce; |
| 308 | |
| 309 | /* for hardware automagic (such as pxa) */ |
| 310 | case -ECONNABORTED: /* endpoint reset */ |
| 311 | DBG(dev, "rx %s reset\n", ep->name); |
| 312 | defer_kevent(dev, WORK_RX_MEMORY); |
| 313 | quiesce: |
| 314 | dev_kfree_skb_any(skb); |
| 315 | goto clean; |
| 316 | |
| 317 | /* data overrun */ |
| 318 | case -EOVERFLOW: |
| 319 | dev->net->stats.rx_over_errors++; |
| 320 | /* FALLTHROUGH */ |
| 321 | |
| 322 | default: |
| 323 | dev->net->stats.rx_errors++; |
| 324 | DBG(dev, "rx status %d\n", status); |
| 325 | break; |
| 326 | } |
| 327 | |
| 328 | if (skb) |
| 329 | dev_kfree_skb_any(skb); |
| 330 | if (!netif_running(dev->net)) { |
| 331 | clean: |
| 332 | spin_lock(&dev->req_lock); |
| 333 | list_add(&req->list, &dev->rx_reqs); |
| 334 | spin_unlock(&dev->req_lock); |
| 335 | req = NULL; |
| 336 | } |
| 337 | if (req) |
| 338 | rx_submit(dev, req, GFP_ATOMIC); |
| 339 | } |
| 340 | |
| 341 | static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n) |
| 342 | { |
| 343 | unsigned i; |
| 344 | struct usb_request *req; |
| 345 | |
| 346 | if (!n) |
| 347 | return -ENOMEM; |
| 348 | |
| 349 | /* queue/recycle up to N requests */ |
| 350 | i = n; |
| 351 | list_for_each_entry(req, list, list) { |
| 352 | if (i-- == 0) |
| 353 | goto extra; |
| 354 | } |
| 355 | while (i--) { |
| 356 | req = usb_ep_alloc_request(ep, GFP_ATOMIC); |
| 357 | if (!req) |
| 358 | return list_empty(list) ? -ENOMEM : 0; |
| 359 | list_add(&req->list, list); |
| 360 | } |
| 361 | return 0; |
| 362 | |
| 363 | extra: |
| 364 | /* free extras */ |
| 365 | for (;;) { |
| 366 | struct list_head *next; |
| 367 | |
| 368 | next = req->list.next; |
| 369 | list_del(&req->list); |
| 370 | usb_ep_free_request(ep, req); |
| 371 | |
| 372 | if (next == list) |
| 373 | break; |
| 374 | |
| 375 | req = container_of(next, struct usb_request, list); |
| 376 | } |
| 377 | return 0; |
| 378 | } |
| 379 | |
| 380 | static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n) |
| 381 | { |
| 382 | int status; |
| 383 | |
| 384 | spin_lock(&dev->req_lock); |
| 385 | status = prealloc(&dev->tx_reqs, link->in_ep, n); |
| 386 | if (status < 0) |
| 387 | goto fail; |
| 388 | status = prealloc(&dev->rx_reqs, link->out_ep, n); |
| 389 | if (status < 0) |
| 390 | goto fail; |
| 391 | goto done; |
| 392 | fail: |
| 393 | DBG(dev, "can't alloc requests\n"); |
| 394 | done: |
| 395 | spin_unlock(&dev->req_lock); |
| 396 | return status; |
| 397 | } |
| 398 | |
| 399 | static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags) |
| 400 | { |
| 401 | struct usb_request *req; |
| 402 | unsigned long flags; |
| 403 | |
| 404 | /* fill unused rxq slots with some skb */ |
| 405 | spin_lock_irqsave(&dev->req_lock, flags); |
| 406 | while (!list_empty(&dev->rx_reqs)) { |
| 407 | req = container_of(dev->rx_reqs.next, |
| 408 | struct usb_request, list); |
| 409 | list_del_init(&req->list); |
| 410 | spin_unlock_irqrestore(&dev->req_lock, flags); |
| 411 | |
| 412 | if (rx_submit(dev, req, gfp_flags) < 0) { |
| 413 | defer_kevent(dev, WORK_RX_MEMORY); |
| 414 | return; |
| 415 | } |
| 416 | |
| 417 | spin_lock_irqsave(&dev->req_lock, flags); |
| 418 | } |
| 419 | spin_unlock_irqrestore(&dev->req_lock, flags); |
| 420 | } |
| 421 | |
| 422 | static void eth_work(struct work_struct *work) |
| 423 | { |
| 424 | struct eth_dev *dev = container_of(work, struct eth_dev, work); |
| 425 | |
| 426 | if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) { |
| 427 | if (netif_running(dev->net)) |
| 428 | rx_fill(dev, GFP_KERNEL); |
| 429 | } |
| 430 | |
| 431 | if (dev->todo) |
| 432 | DBG(dev, "work done, flags = 0x%lx\n", dev->todo); |
| 433 | } |
| 434 | |
| 435 | static void tx_complete(struct usb_ep *ep, struct usb_request *req) |
| 436 | { |
| 437 | struct sk_buff *skb = req->context; |
| 438 | struct eth_dev *dev = ep->driver_data; |
| 439 | |
| 440 | switch (req->status) { |
| 441 | default: |
| 442 | dev->net->stats.tx_errors++; |
| 443 | VDBG(dev, "tx err %d\n", req->status); |
| 444 | /* FALLTHROUGH */ |
| 445 | case -ECONNRESET: /* unlink */ |
| 446 | case -ESHUTDOWN: /* disconnect etc */ |
| 447 | break; |
| 448 | case 0: |
| 449 | dev->net->stats.tx_bytes += skb->len; |
| 450 | } |
| 451 | dev->net->stats.tx_packets++; |
| 452 | |
| 453 | spin_lock(&dev->req_lock); |
| 454 | list_add(&req->list, &dev->tx_reqs); |
| 455 | spin_unlock(&dev->req_lock); |
| 456 | dev_kfree_skb_any(skb); |
| 457 | |
| 458 | atomic_dec(&dev->tx_qlen); |
| 459 | if (netif_carrier_ok(dev->net)) |
| 460 | netif_wake_queue(dev->net); |
| 461 | } |
| 462 | |
| 463 | static inline int is_promisc(u16 cdc_filter) |
| 464 | { |
| 465 | return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS; |
| 466 | } |
| 467 | |
Stephen Hemminger | 25a79c4 | 2009-08-31 19:50:45 +0000 | [diff] [blame] | 468 | static netdev_tx_t eth_start_xmit(struct sk_buff *skb, |
| 469 | struct net_device *net) |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 470 | { |
| 471 | struct eth_dev *dev = netdev_priv(net); |
| 472 | int length = skb->len; |
| 473 | int retval; |
| 474 | struct usb_request *req = NULL; |
| 475 | unsigned long flags; |
| 476 | struct usb_ep *in; |
| 477 | u16 cdc_filter; |
| 478 | |
| 479 | spin_lock_irqsave(&dev->lock, flags); |
| 480 | if (dev->port_usb) { |
| 481 | in = dev->port_usb->in_ep; |
| 482 | cdc_filter = dev->port_usb->cdc_filter; |
| 483 | } else { |
| 484 | in = NULL; |
| 485 | cdc_filter = 0; |
| 486 | } |
| 487 | spin_unlock_irqrestore(&dev->lock, flags); |
| 488 | |
| 489 | if (!in) { |
| 490 | dev_kfree_skb_any(skb); |
Patrick McHardy | 6ed1065 | 2009-06-23 06:03:08 +0000 | [diff] [blame] | 491 | return NETDEV_TX_OK; |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 492 | } |
| 493 | |
| 494 | /* apply outgoing CDC or RNDIS filters */ |
| 495 | if (!is_promisc(cdc_filter)) { |
| 496 | u8 *dest = skb->data; |
| 497 | |
| 498 | if (is_multicast_ether_addr(dest)) { |
| 499 | u16 type; |
| 500 | |
| 501 | /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host |
| 502 | * SET_ETHERNET_MULTICAST_FILTERS requests |
| 503 | */ |
| 504 | if (is_broadcast_ether_addr(dest)) |
| 505 | type = USB_CDC_PACKET_TYPE_BROADCAST; |
| 506 | else |
| 507 | type = USB_CDC_PACKET_TYPE_ALL_MULTICAST; |
| 508 | if (!(cdc_filter & type)) { |
| 509 | dev_kfree_skb_any(skb); |
Patrick McHardy | 6ed1065 | 2009-06-23 06:03:08 +0000 | [diff] [blame] | 510 | return NETDEV_TX_OK; |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 511 | } |
| 512 | } |
| 513 | /* ignores USB_CDC_PACKET_TYPE_DIRECTED */ |
| 514 | } |
| 515 | |
| 516 | spin_lock_irqsave(&dev->req_lock, flags); |
| 517 | /* |
| 518 | * this freelist can be empty if an interrupt triggered disconnect() |
| 519 | * and reconfigured the gadget (shutting down this queue) after the |
| 520 | * network stack decided to xmit but before we got the spinlock. |
| 521 | */ |
| 522 | if (list_empty(&dev->tx_reqs)) { |
| 523 | spin_unlock_irqrestore(&dev->req_lock, flags); |
Patrick McHardy | 5b54814 | 2009-06-12 06:22:29 +0000 | [diff] [blame] | 524 | return NETDEV_TX_BUSY; |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 525 | } |
| 526 | |
| 527 | req = container_of(dev->tx_reqs.next, struct usb_request, list); |
| 528 | list_del(&req->list); |
| 529 | |
| 530 | /* temporarily stop TX queue when the freelist empties */ |
| 531 | if (list_empty(&dev->tx_reqs)) |
| 532 | netif_stop_queue(net); |
| 533 | spin_unlock_irqrestore(&dev->req_lock, flags); |
| 534 | |
| 535 | /* no buffer copies needed, unless the network stack did it |
| 536 | * or the hardware can't use skb buffers. |
| 537 | * or there's not enough space for extra headers we need |
| 538 | */ |
| 539 | if (dev->wrap) { |
| 540 | struct sk_buff *skb_new; |
| 541 | |
| 542 | skb_new = dev->wrap(skb); |
| 543 | if (!skb_new) |
| 544 | goto drop; |
| 545 | |
| 546 | dev_kfree_skb_any(skb); |
| 547 | skb = skb_new; |
| 548 | length = skb->len; |
| 549 | } |
| 550 | req->buf = skb->data; |
| 551 | req->context = skb; |
| 552 | req->complete = tx_complete; |
| 553 | |
| 554 | /* use zlp framing on tx for strict CDC-Ether conformance, |
| 555 | * though any robust network rx path ignores extra padding. |
| 556 | * and some hardware doesn't like to write zlps. |
| 557 | */ |
| 558 | req->zero = 1; |
| 559 | if (!dev->zlp && (length % in->maxpacket) == 0) |
| 560 | length++; |
| 561 | |
| 562 | req->length = length; |
| 563 | |
| 564 | /* throttle highspeed IRQ rate back slightly */ |
| 565 | if (gadget_is_dualspeed(dev->gadget)) |
| 566 | req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH) |
| 567 | ? ((atomic_read(&dev->tx_qlen) % qmult) != 0) |
| 568 | : 0; |
| 569 | |
| 570 | retval = usb_ep_queue(in, req, GFP_ATOMIC); |
| 571 | switch (retval) { |
| 572 | default: |
| 573 | DBG(dev, "tx queue err %d\n", retval); |
| 574 | break; |
| 575 | case 0: |
| 576 | net->trans_start = jiffies; |
| 577 | atomic_inc(&dev->tx_qlen); |
| 578 | } |
| 579 | |
| 580 | if (retval) { |
| 581 | drop: |
| 582 | dev->net->stats.tx_dropped++; |
| 583 | dev_kfree_skb_any(skb); |
| 584 | spin_lock_irqsave(&dev->req_lock, flags); |
| 585 | if (list_empty(&dev->tx_reqs)) |
| 586 | netif_start_queue(net); |
| 587 | list_add(&req->list, &dev->tx_reqs); |
| 588 | spin_unlock_irqrestore(&dev->req_lock, flags); |
| 589 | } |
Patrick McHardy | 6ed1065 | 2009-06-23 06:03:08 +0000 | [diff] [blame] | 590 | return NETDEV_TX_OK; |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 591 | } |
| 592 | |
| 593 | /*-------------------------------------------------------------------------*/ |
| 594 | |
| 595 | static void eth_start(struct eth_dev *dev, gfp_t gfp_flags) |
| 596 | { |
| 597 | DBG(dev, "%s\n", __func__); |
| 598 | |
| 599 | /* fill the rx queue */ |
| 600 | rx_fill(dev, gfp_flags); |
| 601 | |
| 602 | /* and open the tx floodgates */ |
| 603 | atomic_set(&dev->tx_qlen, 0); |
| 604 | netif_wake_queue(dev->net); |
| 605 | } |
| 606 | |
| 607 | static int eth_open(struct net_device *net) |
| 608 | { |
| 609 | struct eth_dev *dev = netdev_priv(net); |
| 610 | struct gether *link; |
| 611 | |
| 612 | DBG(dev, "%s\n", __func__); |
| 613 | if (netif_carrier_ok(dev->net)) |
| 614 | eth_start(dev, GFP_KERNEL); |
| 615 | |
| 616 | spin_lock_irq(&dev->lock); |
| 617 | link = dev->port_usb; |
| 618 | if (link && link->open) |
| 619 | link->open(link); |
| 620 | spin_unlock_irq(&dev->lock); |
| 621 | |
| 622 | return 0; |
| 623 | } |
| 624 | |
| 625 | static int eth_stop(struct net_device *net) |
| 626 | { |
| 627 | struct eth_dev *dev = netdev_priv(net); |
| 628 | unsigned long flags; |
| 629 | |
| 630 | VDBG(dev, "%s\n", __func__); |
| 631 | netif_stop_queue(net); |
| 632 | |
| 633 | DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n", |
| 634 | dev->net->stats.rx_packets, dev->net->stats.tx_packets, |
| 635 | dev->net->stats.rx_errors, dev->net->stats.tx_errors |
| 636 | ); |
| 637 | |
| 638 | /* ensure there are no more active requests */ |
| 639 | spin_lock_irqsave(&dev->lock, flags); |
| 640 | if (dev->port_usb) { |
| 641 | struct gether *link = dev->port_usb; |
| 642 | |
| 643 | if (link->close) |
| 644 | link->close(link); |
| 645 | |
| 646 | /* NOTE: we have no abort-queue primitive we could use |
| 647 | * to cancel all pending I/O. Instead, we disable then |
| 648 | * reenable the endpoints ... this idiom may leave toggle |
| 649 | * wrong, but that's a self-correcting error. |
| 650 | * |
| 651 | * REVISIT: we *COULD* just let the transfers complete at |
| 652 | * their own pace; the network stack can handle old packets. |
| 653 | * For the moment we leave this here, since it works. |
| 654 | */ |
| 655 | usb_ep_disable(link->in_ep); |
| 656 | usb_ep_disable(link->out_ep); |
| 657 | if (netif_carrier_ok(net)) { |
| 658 | DBG(dev, "host still using in/out endpoints\n"); |
| 659 | usb_ep_enable(link->in_ep, link->in); |
| 660 | usb_ep_enable(link->out_ep, link->out); |
| 661 | } |
| 662 | } |
| 663 | spin_unlock_irqrestore(&dev->lock, flags); |
| 664 | |
| 665 | return 0; |
| 666 | } |
| 667 | |
| 668 | /*-------------------------------------------------------------------------*/ |
| 669 | |
| 670 | /* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */ |
| 671 | static char *dev_addr; |
| 672 | module_param(dev_addr, charp, S_IRUGO); |
| 673 | MODULE_PARM_DESC(dev_addr, "Device Ethernet Address"); |
| 674 | |
| 675 | /* this address is invisible to ifconfig */ |
| 676 | static char *host_addr; |
| 677 | module_param(host_addr, charp, S_IRUGO); |
| 678 | MODULE_PARM_DESC(host_addr, "Host Ethernet Address"); |
| 679 | |
| 680 | |
| 681 | static u8 __init nibble(unsigned char c) |
| 682 | { |
| 683 | if (isdigit(c)) |
| 684 | return c - '0'; |
| 685 | c = toupper(c); |
| 686 | if (isxdigit(c)) |
| 687 | return 10 + c - 'A'; |
| 688 | return 0; |
| 689 | } |
| 690 | |
| 691 | static int __init 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 = nibble(*str++) << 4; |
| 702 | num |= (nibble(*str++)); |
| 703 | dev_addr [i] = num; |
| 704 | } |
| 705 | if (is_valid_ether_addr(dev_addr)) |
| 706 | return 0; |
| 707 | } |
| 708 | random_ether_addr(dev_addr); |
| 709 | return 1; |
| 710 | } |
| 711 | |
| 712 | static struct eth_dev *the_dev; |
| 713 | |
Stephen Hemminger | 5ec38f3 | 2009-01-07 18:05:39 -0800 | [diff] [blame] | 714 | static const struct net_device_ops eth_netdev_ops = { |
| 715 | .ndo_open = eth_open, |
| 716 | .ndo_stop = eth_stop, |
| 717 | .ndo_start_xmit = eth_start_xmit, |
| 718 | .ndo_change_mtu = ueth_change_mtu, |
| 719 | .ndo_set_mac_address = eth_mac_addr, |
| 720 | .ndo_validate_addr = eth_validate_addr, |
| 721 | }; |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 722 | |
| 723 | /** |
| 724 | * gether_setup - initialize one ethernet-over-usb link |
| 725 | * @g: gadget to associated with these links |
| 726 | * @ethaddr: NULL, or a buffer in which the ethernet address of the |
| 727 | * host side of the link is recorded |
| 728 | * Context: may sleep |
| 729 | * |
| 730 | * This sets up the single network link that may be exported by a |
| 731 | * gadget driver using this framework. The link layer addresses are |
| 732 | * set up using module parameters. |
| 733 | * |
| 734 | * Returns negative errno, or zero on success |
| 735 | */ |
| 736 | int __init gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN]) |
| 737 | { |
| 738 | struct eth_dev *dev; |
| 739 | struct net_device *net; |
| 740 | int status; |
| 741 | |
| 742 | if (the_dev) |
| 743 | return -EBUSY; |
| 744 | |
| 745 | net = alloc_etherdev(sizeof *dev); |
| 746 | if (!net) |
| 747 | return -ENOMEM; |
| 748 | |
| 749 | dev = netdev_priv(net); |
| 750 | spin_lock_init(&dev->lock); |
| 751 | spin_lock_init(&dev->req_lock); |
| 752 | INIT_WORK(&dev->work, eth_work); |
| 753 | INIT_LIST_HEAD(&dev->tx_reqs); |
| 754 | INIT_LIST_HEAD(&dev->rx_reqs); |
| 755 | |
| 756 | /* network device setup */ |
| 757 | dev->net = net; |
| 758 | strcpy(net->name, "usb%d"); |
| 759 | |
| 760 | if (get_ether_addr(dev_addr, net->dev_addr)) |
| 761 | dev_warn(&g->dev, |
| 762 | "using random %s ethernet address\n", "self"); |
| 763 | if (get_ether_addr(host_addr, dev->host_mac)) |
| 764 | dev_warn(&g->dev, |
| 765 | "using random %s ethernet address\n", "host"); |
| 766 | |
| 767 | if (ethaddr) |
| 768 | memcpy(ethaddr, dev->host_mac, ETH_ALEN); |
| 769 | |
Stephen Hemminger | 5ec38f3 | 2009-01-07 18:05:39 -0800 | [diff] [blame] | 770 | net->netdev_ops = ð_netdev_ops; |
| 771 | |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 772 | SET_ETHTOOL_OPS(net, &ops); |
| 773 | |
| 774 | /* two kinds of host-initiated state changes: |
| 775 | * - iff DATA transfer is active, carrier is "on" |
| 776 | * - tx queueing enabled if open *and* carrier is "on" |
| 777 | */ |
| 778 | netif_stop_queue(net); |
| 779 | netif_carrier_off(net); |
| 780 | |
| 781 | dev->gadget = g; |
| 782 | SET_NETDEV_DEV(net, &g->dev); |
| 783 | |
| 784 | status = register_netdev(net); |
| 785 | if (status < 0) { |
| 786 | dev_dbg(&g->dev, "register_netdev failed, %d\n", status); |
| 787 | free_netdev(net); |
| 788 | } else { |
Johannes Berg | e174961 | 2008-10-27 15:59:26 -0700 | [diff] [blame] | 789 | INFO(dev, "MAC %pM\n", net->dev_addr); |
| 790 | INFO(dev, "HOST MAC %pM\n", dev->host_mac); |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 791 | |
| 792 | the_dev = dev; |
| 793 | } |
| 794 | |
| 795 | return status; |
| 796 | } |
| 797 | |
| 798 | /** |
| 799 | * gether_cleanup - remove Ethernet-over-USB device |
| 800 | * Context: may sleep |
| 801 | * |
| 802 | * This is called to free all resources allocated by @gether_setup(). |
| 803 | */ |
| 804 | void gether_cleanup(void) |
| 805 | { |
| 806 | if (!the_dev) |
| 807 | return; |
| 808 | |
| 809 | unregister_netdev(the_dev->net); |
| 810 | free_netdev(the_dev->net); |
| 811 | |
| 812 | /* assuming we used keventd, it must quiesce too */ |
| 813 | flush_scheduled_work(); |
| 814 | |
| 815 | the_dev = NULL; |
| 816 | } |
| 817 | |
| 818 | |
| 819 | /** |
| 820 | * gether_connect - notify network layer that USB link is active |
| 821 | * @link: the USB link, set up with endpoints, descriptors matching |
| 822 | * current device speed, and any framing wrapper(s) set up. |
| 823 | * Context: irqs blocked |
| 824 | * |
| 825 | * This is called to activate endpoints and let the network layer know |
| 826 | * the connection is active ("carrier detect"). It may cause the I/O |
| 827 | * queues to open and start letting network packets flow, but will in |
| 828 | * any case activate the endpoints so that they respond properly to the |
| 829 | * USB host. |
| 830 | * |
| 831 | * Verify net_device pointer returned using IS_ERR(). If it doesn't |
| 832 | * indicate some error code (negative errno), ep->driver_data values |
| 833 | * have been overwritten. |
| 834 | */ |
| 835 | struct net_device *gether_connect(struct gether *link) |
| 836 | { |
| 837 | struct eth_dev *dev = the_dev; |
| 838 | int result = 0; |
| 839 | |
| 840 | if (!dev) |
| 841 | return ERR_PTR(-EINVAL); |
| 842 | |
| 843 | link->in_ep->driver_data = dev; |
| 844 | result = usb_ep_enable(link->in_ep, link->in); |
| 845 | if (result != 0) { |
| 846 | DBG(dev, "enable %s --> %d\n", |
| 847 | link->in_ep->name, result); |
| 848 | goto fail0; |
| 849 | } |
| 850 | |
| 851 | link->out_ep->driver_data = dev; |
| 852 | result = usb_ep_enable(link->out_ep, link->out); |
| 853 | if (result != 0) { |
| 854 | DBG(dev, "enable %s --> %d\n", |
| 855 | link->out_ep->name, result); |
| 856 | goto fail1; |
| 857 | } |
| 858 | |
| 859 | if (result == 0) |
| 860 | result = alloc_requests(dev, link, qlen(dev->gadget)); |
| 861 | |
| 862 | if (result == 0) { |
| 863 | dev->zlp = link->is_zlp_ok; |
| 864 | DBG(dev, "qlen %d\n", qlen(dev->gadget)); |
| 865 | |
| 866 | dev->header_len = link->header_len; |
| 867 | dev->unwrap = link->unwrap; |
| 868 | dev->wrap = link->wrap; |
| 869 | |
| 870 | spin_lock(&dev->lock); |
| 871 | dev->port_usb = link; |
| 872 | link->ioport = dev; |
David Brownell | 29bac7b | 2008-09-06 21:33:49 -0700 | [diff] [blame] | 873 | if (netif_running(dev->net)) { |
| 874 | if (link->open) |
| 875 | link->open(link); |
| 876 | } else { |
| 877 | if (link->close) |
| 878 | link->close(link); |
| 879 | } |
David Brownell | 2b3d942 | 2008-06-19 18:19:28 -0700 | [diff] [blame] | 880 | spin_unlock(&dev->lock); |
| 881 | |
| 882 | netif_carrier_on(dev->net); |
| 883 | if (netif_running(dev->net)) |
| 884 | eth_start(dev, GFP_ATOMIC); |
| 885 | |
| 886 | /* on error, disable any endpoints */ |
| 887 | } else { |
| 888 | (void) usb_ep_disable(link->out_ep); |
| 889 | fail1: |
| 890 | (void) usb_ep_disable(link->in_ep); |
| 891 | } |
| 892 | fail0: |
| 893 | /* caller is responsible for cleanup on error */ |
| 894 | if (result < 0) |
| 895 | return ERR_PTR(result); |
| 896 | return dev->net; |
| 897 | } |
| 898 | |
| 899 | /** |
| 900 | * gether_disconnect - notify network layer that USB link is inactive |
| 901 | * @link: the USB link, on which gether_connect() was called |
| 902 | * Context: irqs blocked |
| 903 | * |
| 904 | * This is called to deactivate endpoints and let the network layer know |
| 905 | * the connection went inactive ("no carrier"). |
| 906 | * |
| 907 | * On return, the state is as if gether_connect() had never been called. |
| 908 | * The endpoints are inactive, and accordingly without active USB I/O. |
| 909 | * Pointers to endpoint descriptors and endpoint private data are nulled. |
| 910 | */ |
| 911 | void gether_disconnect(struct gether *link) |
| 912 | { |
| 913 | struct eth_dev *dev = link->ioport; |
| 914 | struct usb_request *req; |
| 915 | |
| 916 | WARN_ON(!dev); |
| 917 | if (!dev) |
| 918 | return; |
| 919 | |
| 920 | DBG(dev, "%s\n", __func__); |
| 921 | |
| 922 | netif_stop_queue(dev->net); |
| 923 | netif_carrier_off(dev->net); |
| 924 | |
| 925 | /* disable endpoints, forcing (synchronous) completion |
| 926 | * of all pending i/o. then free the request objects |
| 927 | * and forget about the endpoints. |
| 928 | */ |
| 929 | usb_ep_disable(link->in_ep); |
| 930 | spin_lock(&dev->req_lock); |
| 931 | while (!list_empty(&dev->tx_reqs)) { |
| 932 | req = container_of(dev->tx_reqs.next, |
| 933 | struct usb_request, list); |
| 934 | list_del(&req->list); |
| 935 | |
| 936 | spin_unlock(&dev->req_lock); |
| 937 | usb_ep_free_request(link->in_ep, req); |
| 938 | spin_lock(&dev->req_lock); |
| 939 | } |
| 940 | spin_unlock(&dev->req_lock); |
| 941 | link->in_ep->driver_data = NULL; |
| 942 | link->in = NULL; |
| 943 | |
| 944 | usb_ep_disable(link->out_ep); |
| 945 | spin_lock(&dev->req_lock); |
| 946 | while (!list_empty(&dev->rx_reqs)) { |
| 947 | req = container_of(dev->rx_reqs.next, |
| 948 | struct usb_request, list); |
| 949 | list_del(&req->list); |
| 950 | |
| 951 | spin_unlock(&dev->req_lock); |
| 952 | usb_ep_free_request(link->out_ep, req); |
| 953 | spin_lock(&dev->req_lock); |
| 954 | } |
| 955 | spin_unlock(&dev->req_lock); |
| 956 | link->out_ep->driver_data = NULL; |
| 957 | link->out = NULL; |
| 958 | |
| 959 | /* finish forgetting about this USB link episode */ |
| 960 | dev->header_len = 0; |
| 961 | dev->unwrap = NULL; |
| 962 | dev->wrap = NULL; |
| 963 | |
| 964 | spin_lock(&dev->lock); |
| 965 | dev->port_usb = NULL; |
| 966 | link->ioport = NULL; |
| 967 | spin_unlock(&dev->lock); |
| 968 | } |