linux/drivers/usb/gadget/u_ether.c
Linus Torvalds 033d9959ed Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "This is workqueue updates for v3.7-rc1.  A lot of activities this
  round including considerable API and behavior cleanups.

   * delayed_work combines a timer and a work item.  The handling of the
     timer part has always been a bit clunky leading to confusing
     cancelation API with weird corner-case behaviors.  delayed_work is
     updated to use new IRQ safe timer and cancelation now works as
     expected.

   * Another deficiency of delayed_work was lack of the counterpart of
     mod_timer() which led to cancel+queue combinations or open-coded
     timer+work usages.  mod_delayed_work[_on]() are added.

     These two delayed_work changes make delayed_work provide interface
     and behave like timer which is executed with process context.

   * A work item could be executed concurrently on multiple CPUs, which
     is rather unintuitive and made flush_work() behavior confusing and
     half-broken under certain circumstances.  This problem doesn't
     exist for non-reentrant workqueues.  While non-reentrancy check
     isn't free, the overhead is incurred only when a work item bounces
     across different CPUs and even in simulated pathological scenario
     the overhead isn't too high.

     All workqueues are made non-reentrant.  This removes the
     distinction between flush_[delayed_]work() and
     flush_[delayed_]_work_sync().  The former is now as strong as the
     latter and the specified work item is guaranteed to have finished
     execution of any previous queueing on return.

   * In addition to the various bug fixes, Lai redid and simplified CPU
     hotplug handling significantly.

   * Joonsoo introduced system_highpri_wq and used it during CPU
     hotplug.

  There are two merge commits - one to pull in IRQ safe timer from
  tip/timers/core and the other to pull in CPU hotplug fixes from
  wq/for-3.6-fixes as Lai's hotplug restructuring depended on them."

Fixed a number of trivial conflicts, but the more interesting conflicts
were silent ones where the deprecated interfaces had been used by new
code in the merge window, and thus didn't cause any real data conflicts.

Tejun pointed out a few of them, I fixed a couple more.

* 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits)
  workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
  workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
  workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
  workqueue: remove @delayed from cwq_dec_nr_in_flight()
  workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
  workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
  workqueue: use __cpuinit instead of __devinit for cpu callbacks
  workqueue: rename manager_mutex to assoc_mutex
  workqueue: WORKER_REBIND is no longer necessary for idle rebinding
  workqueue: WORKER_REBIND is no longer necessary for busy rebinding
  workqueue: reimplement idle worker rebinding
  workqueue: deprecate __cancel_delayed_work()
  workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
  workqueue: use mod_delayed_work() instead of __cancel + queue
  workqueue: use irqsafe timer for delayed_work
  workqueue: clean up delayed_work initializers and add missing one
  workqueue: make deferrable delayed_work initializer names consistent
  workqueue: cosmetic whitespace updates for macro definitions
  workqueue: deprecate system_nrt[_freezable]_wq
  workqueue: deprecate flush[_delayed]_work_sync()
  ...
2012-10-02 09:54:49 -07:00

993 lines
25 KiB
C

/*
* u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
*
* Copyright (C) 2003-2005,2008 David Brownell
* Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
* Copyright (C) 2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/* #define VERBOSE_DEBUG */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/device.h>
#include <linux/ctype.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include "u_ether.h"
/*
* This component encapsulates the Ethernet link glue needed to provide
* one (!) network link through the USB gadget stack, normally "usb0".
*
* The control and data models are handled by the function driver which
* connects to this code; such as CDC Ethernet (ECM or EEM),
* "CDC Subset", or RNDIS. That includes all descriptor and endpoint
* management.
*
* Link level addressing is handled by this component using module
* parameters; if no such parameters are provided, random link level
* addresses are used. Each end of the link uses one address. The
* host end address is exported in various ways, and is often recorded
* in configuration databases.
*
* The driver which assembles each configuration using such a link is
* responsible for ensuring that each configuration includes at most one
* instance of is network link. (The network layer provides ways for
* this single "physical" link to be used by multiple virtual links.)
*/
#define UETH__VERSION "29-May-2008"
struct eth_dev {
/* lock is held while accessing port_usb
* or updating its backlink port_usb->ioport
*/
spinlock_t lock;
struct gether *port_usb;
struct net_device *net;
struct usb_gadget *gadget;
spinlock_t req_lock; /* guard {rx,tx}_reqs */
struct list_head tx_reqs, rx_reqs;
atomic_t tx_qlen;
struct sk_buff_head rx_frames;
unsigned header_len;
struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
int (*unwrap)(struct gether *,
struct sk_buff *skb,
struct sk_buff_head *list);
struct work_struct work;
unsigned long todo;
#define WORK_RX_MEMORY 0
bool zlp;
u8 host_mac[ETH_ALEN];
};
/*-------------------------------------------------------------------------*/
#define RX_EXTRA 20 /* bytes guarding against rx overflows */
#define DEFAULT_QLEN 2 /* double buffering by default */
static unsigned qmult = 5;
module_param(qmult, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");
/* for dual-speed hardware, use deeper queues at high/super speed */
static inline int qlen(struct usb_gadget *gadget)
{
if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
gadget->speed == USB_SPEED_SUPER))
return qmult * DEFAULT_QLEN;
else
return DEFAULT_QLEN;
}
/*-------------------------------------------------------------------------*/
/* REVISIT there must be a better way than having two sets
* of debug calls ...
*/
#undef DBG
#undef VDBG
#undef ERROR
#undef INFO
#define xprintk(d, level, fmt, args...) \
printk(level "%s: " fmt , (d)->net->name , ## args)
#ifdef DEBUG
#undef DEBUG
#define DBG(dev, fmt, args...) \
xprintk(dev , KERN_DEBUG , fmt , ## args)
#else
#define DBG(dev, fmt, args...) \
do { } while (0)
#endif /* DEBUG */
#ifdef VERBOSE_DEBUG
#define VDBG DBG
#else
#define VDBG(dev, fmt, args...) \
do { } while (0)
#endif /* DEBUG */
#define ERROR(dev, fmt, args...) \
xprintk(dev , KERN_ERR , fmt , ## args)
#define INFO(dev, fmt, args...) \
xprintk(dev , KERN_INFO , fmt , ## args)
/*-------------------------------------------------------------------------*/
/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
static int ueth_change_mtu(struct net_device *net, int new_mtu)
{
struct eth_dev *dev = netdev_priv(net);
unsigned long flags;
int status = 0;
/* don't change MTU on "live" link (peer won't know) */
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
status = -EBUSY;
else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
status = -ERANGE;
else
net->mtu = new_mtu;
spin_unlock_irqrestore(&dev->lock, flags);
return status;
}
static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
{
struct eth_dev *dev = netdev_priv(net);
strlcpy(p->driver, "g_ether", sizeof p->driver);
strlcpy(p->version, UETH__VERSION, sizeof p->version);
strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info);
}
/* REVISIT can also support:
* - WOL (by tracking suspends and issuing remote wakeup)
* - msglevel (implies updated messaging)
* - ... probably more ethtool ops
*/
static const struct ethtool_ops ops = {
.get_drvinfo = eth_get_drvinfo,
.get_link = ethtool_op_get_link,
};
static void defer_kevent(struct eth_dev *dev, int flag)
{
if (test_and_set_bit(flag, &dev->todo))
return;
if (!schedule_work(&dev->work))
ERROR(dev, "kevent %d may have been dropped\n", flag);
else
DBG(dev, "kevent %d scheduled\n", flag);
}
static void rx_complete(struct usb_ep *ep, struct usb_request *req);
static int
rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
{
struct sk_buff *skb;
int retval = -ENOMEM;
size_t size = 0;
struct usb_ep *out;
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
out = dev->port_usb->out_ep;
else
out = NULL;
spin_unlock_irqrestore(&dev->lock, flags);
if (!out)
return -ENOTCONN;
/* Padding up to RX_EXTRA handles minor disagreements with host.
* Normally we use the USB "terminate on short read" convention;
* so allow up to (N*maxpacket), since that memory is normally
* already allocated. Some hardware doesn't deal well with short
* reads (e.g. DMA must be N*maxpacket), so for now don't trim a
* byte off the end (to force hardware errors on overflow).
*
* RNDIS uses internal framing, and explicitly allows senders to
* pad to end-of-packet. That's potentially nice for speed, but
* means receivers can't recover lost synch on their own (because
* new packets don't only start after a short RX).
*/
size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
size += dev->port_usb->header_len;
size += out->maxpacket - 1;
size -= size % out->maxpacket;
if (dev->port_usb->is_fixed)
size = max_t(size_t, size, dev->port_usb->fixed_out_len);
skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
if (skb == NULL) {
DBG(dev, "no rx skb\n");
goto enomem;
}
/* Some platforms perform better when IP packets are aligned,
* but on at least one, checksumming fails otherwise. Note:
* RNDIS headers involve variable numbers of LE32 values.
*/
skb_reserve(skb, NET_IP_ALIGN);
req->buf = skb->data;
req->length = size;
req->complete = rx_complete;
req->context = skb;
retval = usb_ep_queue(out, req, gfp_flags);
if (retval == -ENOMEM)
enomem:
defer_kevent(dev, WORK_RX_MEMORY);
if (retval) {
DBG(dev, "rx submit --> %d\n", retval);
if (skb)
dev_kfree_skb_any(skb);
spin_lock_irqsave(&dev->req_lock, flags);
list_add(&req->list, &dev->rx_reqs);
spin_unlock_irqrestore(&dev->req_lock, flags);
}
return retval;
}
static void rx_complete(struct usb_ep *ep, struct usb_request *req)
{
struct sk_buff *skb = req->context, *skb2;
struct eth_dev *dev = ep->driver_data;
int status = req->status;
switch (status) {
/* normal completion */
case 0:
skb_put(skb, req->actual);
if (dev->unwrap) {
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb) {
status = dev->unwrap(dev->port_usb,
skb,
&dev->rx_frames);
} else {
dev_kfree_skb_any(skb);
status = -ENOTCONN;
}
spin_unlock_irqrestore(&dev->lock, flags);
} else {
skb_queue_tail(&dev->rx_frames, skb);
}
skb = NULL;
skb2 = skb_dequeue(&dev->rx_frames);
while (skb2) {
if (status < 0
|| ETH_HLEN > skb2->len
|| skb2->len > ETH_FRAME_LEN) {
dev->net->stats.rx_errors++;
dev->net->stats.rx_length_errors++;
DBG(dev, "rx length %d\n", skb2->len);
dev_kfree_skb_any(skb2);
goto next_frame;
}
skb2->protocol = eth_type_trans(skb2, dev->net);
dev->net->stats.rx_packets++;
dev->net->stats.rx_bytes += skb2->len;
/* no buffer copies needed, unless hardware can't
* use skb buffers.
*/
status = netif_rx(skb2);
next_frame:
skb2 = skb_dequeue(&dev->rx_frames);
}
break;
/* software-driven interface shutdown */
case -ECONNRESET: /* unlink */
case -ESHUTDOWN: /* disconnect etc */
VDBG(dev, "rx shutdown, code %d\n", status);
goto quiesce;
/* for hardware automagic (such as pxa) */
case -ECONNABORTED: /* endpoint reset */
DBG(dev, "rx %s reset\n", ep->name);
defer_kevent(dev, WORK_RX_MEMORY);
quiesce:
dev_kfree_skb_any(skb);
goto clean;
/* data overrun */
case -EOVERFLOW:
dev->net->stats.rx_over_errors++;
/* FALLTHROUGH */
default:
dev->net->stats.rx_errors++;
DBG(dev, "rx status %d\n", status);
break;
}
if (skb)
dev_kfree_skb_any(skb);
if (!netif_running(dev->net)) {
clean:
spin_lock(&dev->req_lock);
list_add(&req->list, &dev->rx_reqs);
spin_unlock(&dev->req_lock);
req = NULL;
}
if (req)
rx_submit(dev, req, GFP_ATOMIC);
}
static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
{
unsigned i;
struct usb_request *req;
if (!n)
return -ENOMEM;
/* queue/recycle up to N requests */
i = n;
list_for_each_entry(req, list, list) {
if (i-- == 0)
goto extra;
}
while (i--) {
req = usb_ep_alloc_request(ep, GFP_ATOMIC);
if (!req)
return list_empty(list) ? -ENOMEM : 0;
list_add(&req->list, list);
}
return 0;
extra:
/* free extras */
for (;;) {
struct list_head *next;
next = req->list.next;
list_del(&req->list);
usb_ep_free_request(ep, req);
if (next == list)
break;
req = container_of(next, struct usb_request, list);
}
return 0;
}
static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
{
int status;
spin_lock(&dev->req_lock);
status = prealloc(&dev->tx_reqs, link->in_ep, n);
if (status < 0)
goto fail;
status = prealloc(&dev->rx_reqs, link->out_ep, n);
if (status < 0)
goto fail;
goto done;
fail:
DBG(dev, "can't alloc requests\n");
done:
spin_unlock(&dev->req_lock);
return status;
}
static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
{
struct usb_request *req;
unsigned long flags;
/* fill unused rxq slots with some skb */
spin_lock_irqsave(&dev->req_lock, flags);
while (!list_empty(&dev->rx_reqs)) {
req = container_of(dev->rx_reqs.next,
struct usb_request, list);
list_del_init(&req->list);
spin_unlock_irqrestore(&dev->req_lock, flags);
if (rx_submit(dev, req, gfp_flags) < 0) {
defer_kevent(dev, WORK_RX_MEMORY);
return;
}
spin_lock_irqsave(&dev->req_lock, flags);
}
spin_unlock_irqrestore(&dev->req_lock, flags);
}
static void eth_work(struct work_struct *work)
{
struct eth_dev *dev = container_of(work, struct eth_dev, work);
if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
if (netif_running(dev->net))
rx_fill(dev, GFP_KERNEL);
}
if (dev->todo)
DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
}
static void tx_complete(struct usb_ep *ep, struct usb_request *req)
{
struct sk_buff *skb = req->context;
struct eth_dev *dev = ep->driver_data;
switch (req->status) {
default:
dev->net->stats.tx_errors++;
VDBG(dev, "tx err %d\n", req->status);
/* FALLTHROUGH */
case -ECONNRESET: /* unlink */
case -ESHUTDOWN: /* disconnect etc */
break;
case 0:
dev->net->stats.tx_bytes += skb->len;
}
dev->net->stats.tx_packets++;
spin_lock(&dev->req_lock);
list_add(&req->list, &dev->tx_reqs);
spin_unlock(&dev->req_lock);
dev_kfree_skb_any(skb);
atomic_dec(&dev->tx_qlen);
if (netif_carrier_ok(dev->net))
netif_wake_queue(dev->net);
}
static inline int is_promisc(u16 cdc_filter)
{
return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
}
static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
int length = skb->len;
int retval;
struct usb_request *req = NULL;
unsigned long flags;
struct usb_ep *in;
u16 cdc_filter;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb) {
in = dev->port_usb->in_ep;
cdc_filter = dev->port_usb->cdc_filter;
} else {
in = NULL;
cdc_filter = 0;
}
spin_unlock_irqrestore(&dev->lock, flags);
if (!in) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/* apply outgoing CDC or RNDIS filters */
if (!is_promisc(cdc_filter)) {
u8 *dest = skb->data;
if (is_multicast_ether_addr(dest)) {
u16 type;
/* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
* SET_ETHERNET_MULTICAST_FILTERS requests
*/
if (is_broadcast_ether_addr(dest))
type = USB_CDC_PACKET_TYPE_BROADCAST;
else
type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
if (!(cdc_filter & type)) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
}
/* ignores USB_CDC_PACKET_TYPE_DIRECTED */
}
spin_lock_irqsave(&dev->req_lock, flags);
/*
* this freelist can be empty if an interrupt triggered disconnect()
* and reconfigured the gadget (shutting down this queue) after the
* network stack decided to xmit but before we got the spinlock.
*/
if (list_empty(&dev->tx_reqs)) {
spin_unlock_irqrestore(&dev->req_lock, flags);
return NETDEV_TX_BUSY;
}
req = container_of(dev->tx_reqs.next, struct usb_request, list);
list_del(&req->list);
/* temporarily stop TX queue when the freelist empties */
if (list_empty(&dev->tx_reqs))
netif_stop_queue(net);
spin_unlock_irqrestore(&dev->req_lock, flags);
/* no buffer copies needed, unless the network stack did it
* or the hardware can't use skb buffers.
* or there's not enough space for extra headers we need
*/
if (dev->wrap) {
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
skb = dev->wrap(dev->port_usb, skb);
spin_unlock_irqrestore(&dev->lock, flags);
if (!skb)
goto drop;
length = skb->len;
}
req->buf = skb->data;
req->context = skb;
req->complete = tx_complete;
/* NCM requires no zlp if transfer is dwNtbInMaxSize */
if (dev->port_usb->is_fixed &&
length == dev->port_usb->fixed_in_len &&
(length % in->maxpacket) == 0)
req->zero = 0;
else
req->zero = 1;
/* use zlp framing on tx for strict CDC-Ether conformance,
* though any robust network rx path ignores extra padding.
* and some hardware doesn't like to write zlps.
*/
if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
length++;
req->length = length;
/* throttle high/super speed IRQ rate back slightly */
if (gadget_is_dualspeed(dev->gadget))
req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH ||
dev->gadget->speed == USB_SPEED_SUPER)
? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
: 0;
retval = usb_ep_queue(in, req, GFP_ATOMIC);
switch (retval) {
default:
DBG(dev, "tx queue err %d\n", retval);
break;
case 0:
net->trans_start = jiffies;
atomic_inc(&dev->tx_qlen);
}
if (retval) {
dev_kfree_skb_any(skb);
drop:
dev->net->stats.tx_dropped++;
spin_lock_irqsave(&dev->req_lock, flags);
if (list_empty(&dev->tx_reqs))
netif_start_queue(net);
list_add(&req->list, &dev->tx_reqs);
spin_unlock_irqrestore(&dev->req_lock, flags);
}
return NETDEV_TX_OK;
}
/*-------------------------------------------------------------------------*/
static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
{
DBG(dev, "%s\n", __func__);
/* fill the rx queue */
rx_fill(dev, gfp_flags);
/* and open the tx floodgates */
atomic_set(&dev->tx_qlen, 0);
netif_wake_queue(dev->net);
}
static int eth_open(struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
struct gether *link;
DBG(dev, "%s\n", __func__);
if (netif_carrier_ok(dev->net))
eth_start(dev, GFP_KERNEL);
spin_lock_irq(&dev->lock);
link = dev->port_usb;
if (link && link->open)
link->open(link);
spin_unlock_irq(&dev->lock);
return 0;
}
static int eth_stop(struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
unsigned long flags;
VDBG(dev, "%s\n", __func__);
netif_stop_queue(net);
DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
dev->net->stats.rx_packets, dev->net->stats.tx_packets,
dev->net->stats.rx_errors, dev->net->stats.tx_errors
);
/* ensure there are no more active requests */
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb) {
struct gether *link = dev->port_usb;
const struct usb_endpoint_descriptor *in;
const struct usb_endpoint_descriptor *out;
if (link->close)
link->close(link);
/* NOTE: we have no abort-queue primitive we could use
* to cancel all pending I/O. Instead, we disable then
* reenable the endpoints ... this idiom may leave toggle
* wrong, but that's a self-correcting error.
*
* REVISIT: we *COULD* just let the transfers complete at
* their own pace; the network stack can handle old packets.
* For the moment we leave this here, since it works.
*/
in = link->in_ep->desc;
out = link->out_ep->desc;
usb_ep_disable(link->in_ep);
usb_ep_disable(link->out_ep);
if (netif_carrier_ok(net)) {
DBG(dev, "host still using in/out endpoints\n");
link->in_ep->desc = in;
link->out_ep->desc = out;
usb_ep_enable(link->in_ep);
usb_ep_enable(link->out_ep);
}
}
spin_unlock_irqrestore(&dev->lock, flags);
return 0;
}
/*-------------------------------------------------------------------------*/
/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
static char *dev_addr;
module_param(dev_addr, charp, S_IRUGO);
MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
/* this address is invisible to ifconfig */
static char *host_addr;
module_param(host_addr, charp, S_IRUGO);
MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
static int get_ether_addr(const char *str, u8 *dev_addr)
{
if (str) {
unsigned i;
for (i = 0; i < 6; i++) {
unsigned char num;
if ((*str == '.') || (*str == ':'))
str++;
num = hex_to_bin(*str++) << 4;
num |= hex_to_bin(*str++);
dev_addr [i] = num;
}
if (is_valid_ether_addr(dev_addr))
return 0;
}
eth_random_addr(dev_addr);
return 1;
}
static struct eth_dev *the_dev;
static const struct net_device_ops eth_netdev_ops = {
.ndo_open = eth_open,
.ndo_stop = eth_stop,
.ndo_start_xmit = eth_start_xmit,
.ndo_change_mtu = ueth_change_mtu,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
};
static struct device_type gadget_type = {
.name = "gadget",
};
/**
* gether_setup_name - initialize one ethernet-over-usb link
* @g: gadget to associated with these links
* @ethaddr: NULL, or a buffer in which the ethernet address of the
* host side of the link is recorded
* @netname: name for network device (for example, "usb")
* Context: may sleep
*
* This sets up the single network link that may be exported by a
* gadget driver using this framework. The link layer addresses are
* set up using module parameters.
*
* Returns negative errno, or zero on success
*/
int gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
const char *netname)
{
struct eth_dev *dev;
struct net_device *net;
int status;
if (the_dev)
return -EBUSY;
net = alloc_etherdev(sizeof *dev);
if (!net)
return -ENOMEM;
dev = netdev_priv(net);
spin_lock_init(&dev->lock);
spin_lock_init(&dev->req_lock);
INIT_WORK(&dev->work, eth_work);
INIT_LIST_HEAD(&dev->tx_reqs);
INIT_LIST_HEAD(&dev->rx_reqs);
skb_queue_head_init(&dev->rx_frames);
/* network device setup */
dev->net = net;
snprintf(net->name, sizeof(net->name), "%s%%d", netname);
if (get_ether_addr(dev_addr, net->dev_addr))
dev_warn(&g->dev,
"using random %s ethernet address\n", "self");
if (get_ether_addr(host_addr, dev->host_mac))
dev_warn(&g->dev,
"using random %s ethernet address\n", "host");
if (ethaddr)
memcpy(ethaddr, dev->host_mac, ETH_ALEN);
net->netdev_ops = &eth_netdev_ops;
SET_ETHTOOL_OPS(net, &ops);
dev->gadget = g;
SET_NETDEV_DEV(net, &g->dev);
SET_NETDEV_DEVTYPE(net, &gadget_type);
status = register_netdev(net);
if (status < 0) {
dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
free_netdev(net);
} else {
INFO(dev, "MAC %pM\n", net->dev_addr);
INFO(dev, "HOST MAC %pM\n", dev->host_mac);
the_dev = dev;
/* two kinds of host-initiated state changes:
* - iff DATA transfer is active, carrier is "on"
* - tx queueing enabled if open *and* carrier is "on"
*/
netif_carrier_off(net);
}
return status;
}
/**
* gether_cleanup - remove Ethernet-over-USB device
* Context: may sleep
*
* This is called to free all resources allocated by @gether_setup().
*/
void gether_cleanup(void)
{
if (!the_dev)
return;
unregister_netdev(the_dev->net);
flush_work(&the_dev->work);
free_netdev(the_dev->net);
the_dev = NULL;
}
/**
* gether_connect - notify network layer that USB link is active
* @link: the USB link, set up with endpoints, descriptors matching
* current device speed, and any framing wrapper(s) set up.
* Context: irqs blocked
*
* This is called to activate endpoints and let the network layer know
* the connection is active ("carrier detect"). It may cause the I/O
* queues to open and start letting network packets flow, but will in
* any case activate the endpoints so that they respond properly to the
* USB host.
*
* Verify net_device pointer returned using IS_ERR(). If it doesn't
* indicate some error code (negative errno), ep->driver_data values
* have been overwritten.
*/
struct net_device *gether_connect(struct gether *link)
{
struct eth_dev *dev = the_dev;
int result = 0;
if (!dev)
return ERR_PTR(-EINVAL);
link->in_ep->driver_data = dev;
result = usb_ep_enable(link->in_ep);
if (result != 0) {
DBG(dev, "enable %s --> %d\n",
link->in_ep->name, result);
goto fail0;
}
link->out_ep->driver_data = dev;
result = usb_ep_enable(link->out_ep);
if (result != 0) {
DBG(dev, "enable %s --> %d\n",
link->out_ep->name, result);
goto fail1;
}
if (result == 0)
result = alloc_requests(dev, link, qlen(dev->gadget));
if (result == 0) {
dev->zlp = link->is_zlp_ok;
DBG(dev, "qlen %d\n", qlen(dev->gadget));
dev->header_len = link->header_len;
dev->unwrap = link->unwrap;
dev->wrap = link->wrap;
spin_lock(&dev->lock);
dev->port_usb = link;
link->ioport = dev;
if (netif_running(dev->net)) {
if (link->open)
link->open(link);
} else {
if (link->close)
link->close(link);
}
spin_unlock(&dev->lock);
netif_carrier_on(dev->net);
if (netif_running(dev->net))
eth_start(dev, GFP_ATOMIC);
/* on error, disable any endpoints */
} else {
(void) usb_ep_disable(link->out_ep);
fail1:
(void) usb_ep_disable(link->in_ep);
}
fail0:
/* caller is responsible for cleanup on error */
if (result < 0)
return ERR_PTR(result);
return dev->net;
}
/**
* gether_disconnect - notify network layer that USB link is inactive
* @link: the USB link, on which gether_connect() was called
* Context: irqs blocked
*
* This is called to deactivate endpoints and let the network layer know
* the connection went inactive ("no carrier").
*
* On return, the state is as if gether_connect() had never been called.
* The endpoints are inactive, and accordingly without active USB I/O.
* Pointers to endpoint descriptors and endpoint private data are nulled.
*/
void gether_disconnect(struct gether *link)
{
struct eth_dev *dev = link->ioport;
struct usb_request *req;
WARN_ON(!dev);
if (!dev)
return;
DBG(dev, "%s\n", __func__);
netif_stop_queue(dev->net);
netif_carrier_off(dev->net);
/* disable endpoints, forcing (synchronous) completion
* of all pending i/o. then free the request objects
* and forget about the endpoints.
*/
usb_ep_disable(link->in_ep);
spin_lock(&dev->req_lock);
while (!list_empty(&dev->tx_reqs)) {
req = container_of(dev->tx_reqs.next,
struct usb_request, list);
list_del(&req->list);
spin_unlock(&dev->req_lock);
usb_ep_free_request(link->in_ep, req);
spin_lock(&dev->req_lock);
}
spin_unlock(&dev->req_lock);
link->in_ep->driver_data = NULL;
link->in_ep->desc = NULL;
usb_ep_disable(link->out_ep);
spin_lock(&dev->req_lock);
while (!list_empty(&dev->rx_reqs)) {
req = container_of(dev->rx_reqs.next,
struct usb_request, list);
list_del(&req->list);
spin_unlock(&dev->req_lock);
usb_ep_free_request(link->out_ep, req);
spin_lock(&dev->req_lock);
}
spin_unlock(&dev->req_lock);
link->out_ep->driver_data = NULL;
link->out_ep->desc = NULL;
/* finish forgetting about this USB link episode */
dev->header_len = 0;
dev->unwrap = NULL;
dev->wrap = NULL;
spin_lock(&dev->lock);
dev->port_usb = NULL;
link->ioport = NULL;
spin_unlock(&dev->lock);
}