diff options
Diffstat (limited to 'drivers/net/usb/usbnet.c')
| -rw-r--r-- | drivers/net/usb/usbnet.c | 2227 |
1 files changed, 2227 insertions, 0 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c new file mode 100644 index 000000000..405e588f8 --- /dev/null +++ b/drivers/net/usb/usbnet.c @@ -0,0 +1,2227 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * USB Network driver infrastructure + * Copyright (C) 2000-2005 by David Brownell + * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com> + */ + +/* + * This is a generic "USB networking" framework that works with several + * kinds of full and high speed networking devices: host-to-host cables, + * smart usb peripherals, and actual Ethernet adapters. + * + * These devices usually differ in terms of control protocols (if they + * even have one!) and sometimes they define new framing to wrap or batch + * Ethernet packets. Otherwise, they talk to USB pretty much the same, + * so interface (un)binding, endpoint I/O queues, fault handling, and other + * issues can usefully be addressed by this framework. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/ctype.h> +#include <linux/ethtool.h> +#include <linux/workqueue.h> +#include <linux/mii.h> +#include <linux/usb.h> +#include <linux/usb/usbnet.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/pm_runtime.h> + +/*-------------------------------------------------------------------------*/ + +/* + * Nineteen USB 1.1 max size bulk transactions per frame (ms), max. + * Several dozen bytes of IPv4 data can fit in two such transactions. + * One maximum size Ethernet packet takes twenty four of them. + * For high speed, each frame comfortably fits almost 36 max size + * Ethernet packets (so queues should be bigger). + * + * The goal is to let the USB host controller be busy for 5msec or + * more before an irq is required, under load. Jumbograms change + * the equation. + */ +#define MAX_QUEUE_MEMORY (60 * 1518) +#define RX_QLEN(dev) ((dev)->rx_qlen) +#define TX_QLEN(dev) ((dev)->tx_qlen) + +// reawaken network queue this soon after stopping; else watchdog barks +#define TX_TIMEOUT_JIFFIES (5*HZ) + +/* throttle rx/tx briefly after some faults, so hub_wq might disconnect() + * us (it polls at HZ/4 usually) before we report too many false errors. + */ +#define THROTTLE_JIFFIES (HZ/8) + +// between wakeups +#define UNLINK_TIMEOUT_MS 3 + +/*-------------------------------------------------------------------------*/ + +// randomly generated ethernet address +static u8 node_id [ETH_ALEN]; + +/* use ethtool to change the level for any given device */ +static int msg_level = -1; +module_param (msg_level, int, 0); +MODULE_PARM_DESC (msg_level, "Override default message level"); + +/*-------------------------------------------------------------------------*/ + +static const char * const usbnet_event_names[] = { + [EVENT_TX_HALT] = "EVENT_TX_HALT", + [EVENT_RX_HALT] = "EVENT_RX_HALT", + [EVENT_RX_MEMORY] = "EVENT_RX_MEMORY", + [EVENT_STS_SPLIT] = "EVENT_STS_SPLIT", + [EVENT_LINK_RESET] = "EVENT_LINK_RESET", + [EVENT_RX_PAUSED] = "EVENT_RX_PAUSED", + [EVENT_DEV_ASLEEP] = "EVENT_DEV_ASLEEP", + [EVENT_DEV_OPEN] = "EVENT_DEV_OPEN", + [EVENT_DEVICE_REPORT_IDLE] = "EVENT_DEVICE_REPORT_IDLE", + [EVENT_NO_RUNTIME_PM] = "EVENT_NO_RUNTIME_PM", + [EVENT_RX_KILL] = "EVENT_RX_KILL", + [EVENT_LINK_CHANGE] = "EVENT_LINK_CHANGE", + [EVENT_SET_RX_MODE] = "EVENT_SET_RX_MODE", + [EVENT_NO_IP_ALIGN] = "EVENT_NO_IP_ALIGN", +}; + +/* handles CDC Ethernet and many other network "bulk data" interfaces */ +int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf) +{ + int tmp; + struct usb_host_interface *alt = NULL; + struct usb_host_endpoint *in = NULL, *out = NULL; + struct usb_host_endpoint *status = NULL; + + for (tmp = 0; tmp < intf->num_altsetting; tmp++) { + unsigned ep; + + in = out = status = NULL; + alt = intf->altsetting + tmp; + + /* take the first altsetting with in-bulk + out-bulk; + * remember any status endpoint, just in case; + * ignore other endpoints and altsettings. + */ + for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) { + struct usb_host_endpoint *e; + int intr = 0; + + e = alt->endpoint + ep; + + /* ignore endpoints which cannot transfer data */ + if (!usb_endpoint_maxp(&e->desc)) + continue; + + switch (e->desc.bmAttributes) { + case USB_ENDPOINT_XFER_INT: + if (!usb_endpoint_dir_in(&e->desc)) + continue; + intr = 1; + fallthrough; + case USB_ENDPOINT_XFER_BULK: + break; + default: + continue; + } + if (usb_endpoint_dir_in(&e->desc)) { + if (!intr && !in) + in = e; + else if (intr && !status) + status = e; + } else { + if (!out) + out = e; + } + } + if (in && out) + break; + } + if (!alt || !in || !out) + return -EINVAL; + + if (alt->desc.bAlternateSetting != 0 || + !(dev->driver_info->flags & FLAG_NO_SETINT)) { + tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber, + alt->desc.bAlternateSetting); + if (tmp < 0) + return tmp; + } + + dev->in = usb_rcvbulkpipe (dev->udev, + in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); + dev->out = usb_sndbulkpipe (dev->udev, + out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); + dev->status = status; + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_get_endpoints); + +int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress) +{ + u8 addr[ETH_ALEN]; + int tmp = -1, ret; + unsigned char buf [13]; + + ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf); + if (ret == 12) + tmp = hex2bin(addr, buf, 6); + if (tmp < 0) { + dev_dbg(&dev->udev->dev, + "bad MAC string %d fetch, %d\n", iMACAddress, tmp); + if (ret >= 0) + ret = -EINVAL; + return ret; + } + eth_hw_addr_set(dev->net, addr); + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr); + +static void intr_complete (struct urb *urb) +{ + struct usbnet *dev = urb->context; + int status = urb->status; + + switch (status) { + /* success */ + case 0: + dev->driver_info->status(dev, urb); + break; + + /* software-driven interface shutdown */ + case -ENOENT: /* urb killed */ + case -ESHUTDOWN: /* hardware gone */ + netif_dbg(dev, ifdown, dev->net, + "intr shutdown, code %d\n", status); + return; + + /* NOTE: not throttling like RX/TX, since this endpoint + * already polls infrequently + */ + default: + netdev_dbg(dev->net, "intr status %d\n", status); + break; + } + + status = usb_submit_urb (urb, GFP_ATOMIC); + if (status != 0) + netif_err(dev, timer, dev->net, + "intr resubmit --> %d\n", status); +} + +static int init_status (struct usbnet *dev, struct usb_interface *intf) +{ + char *buf = NULL; + unsigned pipe = 0; + unsigned maxp; + unsigned period; + + if (!dev->driver_info->status) + return 0; + + pipe = usb_rcvintpipe (dev->udev, + dev->status->desc.bEndpointAddress + & USB_ENDPOINT_NUMBER_MASK); + maxp = usb_maxpacket(dev->udev, pipe); + + /* avoid 1 msec chatter: min 8 msec poll rate */ + period = max ((int) dev->status->desc.bInterval, + (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3); + + buf = kmalloc (maxp, GFP_KERNEL); + if (buf) { + dev->interrupt = usb_alloc_urb (0, GFP_KERNEL); + if (!dev->interrupt) { + kfree (buf); + return -ENOMEM; + } else { + usb_fill_int_urb(dev->interrupt, dev->udev, pipe, + buf, maxp, intr_complete, dev, period); + dev->interrupt->transfer_flags |= URB_FREE_BUFFER; + dev_dbg(&intf->dev, + "status ep%din, %d bytes period %d\n", + usb_pipeendpoint(pipe), maxp, period); + } + } + return 0; +} + +/* Submit the interrupt URB if not previously submitted, increasing refcount */ +int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags) +{ + int ret = 0; + + WARN_ON_ONCE(dev->interrupt == NULL); + if (dev->interrupt) { + mutex_lock(&dev->interrupt_mutex); + + if (++dev->interrupt_count == 1) + ret = usb_submit_urb(dev->interrupt, mem_flags); + + dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n", + dev->interrupt_count); + mutex_unlock(&dev->interrupt_mutex); + } + return ret; +} +EXPORT_SYMBOL_GPL(usbnet_status_start); + +/* For resume; submit interrupt URB if previously submitted */ +static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags) +{ + int ret = 0; + + mutex_lock(&dev->interrupt_mutex); + if (dev->interrupt_count) { + ret = usb_submit_urb(dev->interrupt, mem_flags); + dev_dbg(&dev->udev->dev, + "submitted interrupt URB for resume\n"); + } + mutex_unlock(&dev->interrupt_mutex); + return ret; +} + +/* Kill the interrupt URB if all submitters want it killed */ +void usbnet_status_stop(struct usbnet *dev) +{ + if (dev->interrupt) { + mutex_lock(&dev->interrupt_mutex); + WARN_ON(dev->interrupt_count == 0); + + if (dev->interrupt_count && --dev->interrupt_count == 0) + usb_kill_urb(dev->interrupt); + + dev_dbg(&dev->udev->dev, + "decremented interrupt URB count to %d\n", + dev->interrupt_count); + mutex_unlock(&dev->interrupt_mutex); + } +} +EXPORT_SYMBOL_GPL(usbnet_status_stop); + +/* For suspend; always kill interrupt URB */ +static void __usbnet_status_stop_force(struct usbnet *dev) +{ + if (dev->interrupt) { + mutex_lock(&dev->interrupt_mutex); + usb_kill_urb(dev->interrupt); + dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n"); + mutex_unlock(&dev->interrupt_mutex); + } +} + +/* Passes this packet up the stack, updating its accounting. + * Some link protocols batch packets, so their rx_fixup paths + * can return clones as well as just modify the original skb. + */ +void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb) +{ + struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats); + unsigned long flags; + int status; + + if (test_bit(EVENT_RX_PAUSED, &dev->flags)) { + skb_queue_tail(&dev->rxq_pause, skb); + return; + } + + /* only update if unset to allow minidriver rx_fixup override */ + if (skb->protocol == 0) + skb->protocol = eth_type_trans (skb, dev->net); + + flags = u64_stats_update_begin_irqsave(&stats64->syncp); + u64_stats_inc(&stats64->rx_packets); + u64_stats_add(&stats64->rx_bytes, skb->len); + u64_stats_update_end_irqrestore(&stats64->syncp, flags); + + netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n", + skb->len + sizeof (struct ethhdr), skb->protocol); + memset (skb->cb, 0, sizeof (struct skb_data)); + + if (skb_defer_rx_timestamp(skb)) + return; + + status = netif_rx (skb); + if (status != NET_RX_SUCCESS) + netif_dbg(dev, rx_err, dev->net, + "netif_rx status %d\n", status); +} +EXPORT_SYMBOL_GPL(usbnet_skb_return); + +/* must be called if hard_mtu or rx_urb_size changed */ +void usbnet_update_max_qlen(struct usbnet *dev) +{ + enum usb_device_speed speed = dev->udev->speed; + + if (!dev->rx_urb_size || !dev->hard_mtu) + goto insanity; + switch (speed) { + case USB_SPEED_HIGH: + dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size; + dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu; + break; + case USB_SPEED_SUPER: + case USB_SPEED_SUPER_PLUS: + /* + * Not take default 5ms qlen for super speed HC to + * save memory, and iperf tests show 2.5ms qlen can + * work well + */ + dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size; + dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu; + break; + default: +insanity: + dev->rx_qlen = dev->tx_qlen = 4; + } +} +EXPORT_SYMBOL_GPL(usbnet_update_max_qlen); + + +/*------------------------------------------------------------------------- + * + * Network Device Driver (peer link to "Host Device", from USB host) + * + *-------------------------------------------------------------------------*/ + +int usbnet_change_mtu (struct net_device *net, int new_mtu) +{ + struct usbnet *dev = netdev_priv(net); + int ll_mtu = new_mtu + net->hard_header_len; + int old_hard_mtu = dev->hard_mtu; + int old_rx_urb_size = dev->rx_urb_size; + + // no second zero-length packet read wanted after mtu-sized packets + if ((ll_mtu % dev->maxpacket) == 0) + return -EDOM; + net->mtu = new_mtu; + + dev->hard_mtu = net->mtu + net->hard_header_len; + if (dev->rx_urb_size == old_hard_mtu) { + dev->rx_urb_size = dev->hard_mtu; + if (dev->rx_urb_size > old_rx_urb_size) { + usbnet_pause_rx(dev); + usbnet_unlink_rx_urbs(dev); + usbnet_resume_rx(dev); + } + } + + /* max qlen depend on hard_mtu and rx_urb_size */ + usbnet_update_max_qlen(dev); + + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_change_mtu); + +/* The caller must hold list->lock */ +static void __usbnet_queue_skb(struct sk_buff_head *list, + struct sk_buff *newsk, enum skb_state state) +{ + struct skb_data *entry = (struct skb_data *) newsk->cb; + + __skb_queue_tail(list, newsk); + entry->state = state; +} + +/*-------------------------------------------------------------------------*/ + +/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from + * completion callbacks. 2.5 should have fixed those bugs... + */ + +static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb, + struct sk_buff_head *list, enum skb_state state) +{ + unsigned long flags; + enum skb_state old_state; + struct skb_data *entry = (struct skb_data *) skb->cb; + + spin_lock_irqsave(&list->lock, flags); + old_state = entry->state; + entry->state = state; + __skb_unlink(skb, list); + + /* defer_bh() is never called with list == &dev->done. + * spin_lock_nested() tells lockdep that it is OK to take + * dev->done.lock here with list->lock held. + */ + spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING); + + __skb_queue_tail(&dev->done, skb); + if (dev->done.qlen == 1) + tasklet_schedule(&dev->bh); + spin_unlock(&dev->done.lock); + spin_unlock_irqrestore(&list->lock, flags); + return old_state; +} + +/* some work can't be done in tasklets, so we use keventd + * + * NOTE: annoying asymmetry: if it's active, schedule_work() fails, + * but tasklet_schedule() doesn't. hope the failure is rare. + */ +void usbnet_defer_kevent (struct usbnet *dev, int work) +{ + set_bit (work, &dev->flags); + if (!schedule_work (&dev->kevent)) + netdev_dbg(dev->net, "kevent %s may have been dropped\n", usbnet_event_names[work]); + else + netdev_dbg(dev->net, "kevent %s scheduled\n", usbnet_event_names[work]); +} +EXPORT_SYMBOL_GPL(usbnet_defer_kevent); + +/*-------------------------------------------------------------------------*/ + +static void rx_complete (struct urb *urb); + +static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags) +{ + struct sk_buff *skb; + struct skb_data *entry; + int retval = 0; + unsigned long lockflags; + size_t size = dev->rx_urb_size; + + /* prevent rx skb allocation when error ratio is high */ + if (test_bit(EVENT_RX_KILL, &dev->flags)) { + usb_free_urb(urb); + return -ENOLINK; + } + + if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags)) + skb = __netdev_alloc_skb(dev->net, size, flags); + else + skb = __netdev_alloc_skb_ip_align(dev->net, size, flags); + if (!skb) { + netif_dbg(dev, rx_err, dev->net, "no rx skb\n"); + usbnet_defer_kevent (dev, EVENT_RX_MEMORY); + usb_free_urb (urb); + return -ENOMEM; + } + + entry = (struct skb_data *) skb->cb; + entry->urb = urb; + entry->dev = dev; + entry->length = 0; + + usb_fill_bulk_urb (urb, dev->udev, dev->in, + skb->data, size, rx_complete, skb); + + spin_lock_irqsave (&dev->rxq.lock, lockflags); + + if (netif_running (dev->net) && + netif_device_present (dev->net) && + test_bit(EVENT_DEV_OPEN, &dev->flags) && + !test_bit (EVENT_RX_HALT, &dev->flags) && + !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) { + switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) { + case -EPIPE: + usbnet_defer_kevent (dev, EVENT_RX_HALT); + break; + case -ENOMEM: + usbnet_defer_kevent (dev, EVENT_RX_MEMORY); + break; + case -ENODEV: + netif_dbg(dev, ifdown, dev->net, "device gone\n"); + netif_device_detach (dev->net); + break; + case -EHOSTUNREACH: + retval = -ENOLINK; + break; + default: + netif_dbg(dev, rx_err, dev->net, + "rx submit, %d\n", retval); + tasklet_schedule (&dev->bh); + break; + case 0: + __usbnet_queue_skb(&dev->rxq, skb, rx_start); + } + } else { + netif_dbg(dev, ifdown, dev->net, "rx: stopped\n"); + retval = -ENOLINK; + } + spin_unlock_irqrestore (&dev->rxq.lock, lockflags); + if (retval) { + dev_kfree_skb_any (skb); + usb_free_urb (urb); + } + return retval; +} + + +/*-------------------------------------------------------------------------*/ + +static inline void rx_process (struct usbnet *dev, struct sk_buff *skb) +{ + if (dev->driver_info->rx_fixup && + !dev->driver_info->rx_fixup (dev, skb)) { + /* With RX_ASSEMBLE, rx_fixup() must update counters */ + if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE)) + dev->net->stats.rx_errors++; + goto done; + } + // else network stack removes extra byte if we forced a short packet + + /* all data was already cloned from skb inside the driver */ + if (dev->driver_info->flags & FLAG_MULTI_PACKET) + goto done; + + if (skb->len < ETH_HLEN) { + dev->net->stats.rx_errors++; + dev->net->stats.rx_length_errors++; + netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len); + } else { + usbnet_skb_return(dev, skb); + return; + } + +done: + skb_queue_tail(&dev->done, skb); +} + +/*-------------------------------------------------------------------------*/ + +static void rx_complete (struct urb *urb) +{ + struct sk_buff *skb = (struct sk_buff *) urb->context; + struct skb_data *entry = (struct skb_data *) skb->cb; + struct usbnet *dev = entry->dev; + int urb_status = urb->status; + enum skb_state state; + + skb_put (skb, urb->actual_length); + state = rx_done; + entry->urb = NULL; + + switch (urb_status) { + /* success */ + case 0: + break; + + /* stalls need manual reset. this is rare ... except that + * when going through USB 2.0 TTs, unplug appears this way. + * we avoid the highspeed version of the ETIMEDOUT/EILSEQ + * storm, recovering as needed. + */ + case -EPIPE: + dev->net->stats.rx_errors++; + usbnet_defer_kevent (dev, EVENT_RX_HALT); + fallthrough; + + /* software-driven interface shutdown */ + case -ECONNRESET: /* async unlink */ + case -ESHUTDOWN: /* hardware gone */ + netif_dbg(dev, ifdown, dev->net, + "rx shutdown, code %d\n", urb_status); + goto block; + + /* we get controller i/o faults during hub_wq disconnect() delays. + * throttle down resubmits, to avoid log floods; just temporarily, + * so we still recover when the fault isn't a hub_wq delay. + */ + case -EPROTO: + case -ETIME: + case -EILSEQ: + dev->net->stats.rx_errors++; + if (!timer_pending (&dev->delay)) { + mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES); + netif_dbg(dev, link, dev->net, + "rx throttle %d\n", urb_status); + } +block: + state = rx_cleanup; + entry->urb = urb; + urb = NULL; + break; + + /* data overrun ... flush fifo? */ + case -EOVERFLOW: + dev->net->stats.rx_over_errors++; + fallthrough; + + default: + state = rx_cleanup; + dev->net->stats.rx_errors++; + netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status); + break; + } + + /* stop rx if packet error rate is high */ + if (++dev->pkt_cnt > 30) { + dev->pkt_cnt = 0; + dev->pkt_err = 0; + } else { + if (state == rx_cleanup) + dev->pkt_err++; + if (dev->pkt_err > 20) + set_bit(EVENT_RX_KILL, &dev->flags); + } + + state = defer_bh(dev, skb, &dev->rxq, state); + + if (urb) { + if (netif_running (dev->net) && + !test_bit (EVENT_RX_HALT, &dev->flags) && + state != unlink_start) { + rx_submit (dev, urb, GFP_ATOMIC); + usb_mark_last_busy(dev->udev); + return; + } + usb_free_urb (urb); + } + netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n"); +} + +/*-------------------------------------------------------------------------*/ +void usbnet_pause_rx(struct usbnet *dev) +{ + set_bit(EVENT_RX_PAUSED, &dev->flags); + + netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n"); +} +EXPORT_SYMBOL_GPL(usbnet_pause_rx); + +void usbnet_resume_rx(struct usbnet *dev) +{ + struct sk_buff *skb; + int num = 0; + + clear_bit(EVENT_RX_PAUSED, &dev->flags); + + while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) { + usbnet_skb_return(dev, skb); + num++; + } + + tasklet_schedule(&dev->bh); + + netif_dbg(dev, rx_status, dev->net, + "paused rx queue disabled, %d skbs requeued\n", num); +} +EXPORT_SYMBOL_GPL(usbnet_resume_rx); + +void usbnet_purge_paused_rxq(struct usbnet *dev) +{ + skb_queue_purge(&dev->rxq_pause); +} +EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq); + +/*-------------------------------------------------------------------------*/ + +// unlink pending rx/tx; completion handlers do all other cleanup + +static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q) +{ + unsigned long flags; + struct sk_buff *skb; + int count = 0; + + spin_lock_irqsave (&q->lock, flags); + while (!skb_queue_empty(q)) { + struct skb_data *entry; + struct urb *urb; + int retval; + + skb_queue_walk(q, skb) { + entry = (struct skb_data *) skb->cb; + if (entry->state != unlink_start) + goto found; + } + break; +found: + entry->state = unlink_start; + urb = entry->urb; + + /* + * Get reference count of the URB to avoid it to be + * freed during usb_unlink_urb, which may trigger + * use-after-free problem inside usb_unlink_urb since + * usb_unlink_urb is always racing with .complete + * handler(include defer_bh). + */ + usb_get_urb(urb); + spin_unlock_irqrestore(&q->lock, flags); + // during some PM-driven resume scenarios, + // these (async) unlinks complete immediately + retval = usb_unlink_urb (urb); + if (retval != -EINPROGRESS && retval != 0) + netdev_dbg(dev->net, "unlink urb err, %d\n", retval); + else + count++; + usb_put_urb(urb); + spin_lock_irqsave(&q->lock, flags); + } + spin_unlock_irqrestore (&q->lock, flags); + return count; +} + +// Flush all pending rx urbs +// minidrivers may need to do this when the MTU changes + +void usbnet_unlink_rx_urbs(struct usbnet *dev) +{ + if (netif_running(dev->net)) { + (void) unlink_urbs (dev, &dev->rxq); + tasklet_schedule(&dev->bh); + } +} +EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs); + +/*-------------------------------------------------------------------------*/ + +static void wait_skb_queue_empty(struct sk_buff_head *q) +{ + unsigned long flags; + + spin_lock_irqsave(&q->lock, flags); + while (!skb_queue_empty(q)) { + spin_unlock_irqrestore(&q->lock, flags); + schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS)); + set_current_state(TASK_UNINTERRUPTIBLE); + spin_lock_irqsave(&q->lock, flags); + } + spin_unlock_irqrestore(&q->lock, flags); +} + +// precondition: never called in_interrupt +static void usbnet_terminate_urbs(struct usbnet *dev) +{ + DECLARE_WAITQUEUE(wait, current); + int temp; + + /* ensure there are no more active urbs */ + add_wait_queue(&dev->wait, &wait); + set_current_state(TASK_UNINTERRUPTIBLE); + temp = unlink_urbs(dev, &dev->txq) + + unlink_urbs(dev, &dev->rxq); + + /* maybe wait for deletions to finish. */ + wait_skb_queue_empty(&dev->rxq); + wait_skb_queue_empty(&dev->txq); + wait_skb_queue_empty(&dev->done); + netif_dbg(dev, ifdown, dev->net, + "waited for %d urb completions\n", temp); + set_current_state(TASK_RUNNING); + remove_wait_queue(&dev->wait, &wait); +} + +int usbnet_stop (struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + const struct driver_info *info = dev->driver_info; + int retval, pm, mpn; + + clear_bit(EVENT_DEV_OPEN, &dev->flags); + netif_stop_queue (net); + + netif_info(dev, ifdown, dev->net, + "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n", + net->stats.rx_packets, net->stats.tx_packets, + net->stats.rx_errors, net->stats.tx_errors); + + /* to not race resume */ + pm = usb_autopm_get_interface(dev->intf); + /* allow minidriver to stop correctly (wireless devices to turn off + * radio etc) */ + if (info->stop) { + retval = info->stop(dev); + if (retval < 0) + netif_info(dev, ifdown, dev->net, + "stop fail (%d) usbnet usb-%s-%s, %s\n", + retval, + dev->udev->bus->bus_name, dev->udev->devpath, + info->description); + } + + if (!(info->flags & FLAG_AVOID_UNLINK_URBS)) + usbnet_terminate_urbs(dev); + + usbnet_status_stop(dev); + + usbnet_purge_paused_rxq(dev); + + mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags); + + /* deferred work (timer, softirq, task) must also stop */ + dev->flags = 0; + del_timer_sync (&dev->delay); + tasklet_kill (&dev->bh); + cancel_work_sync(&dev->kevent); + if (!pm) + usb_autopm_put_interface(dev->intf); + + if (info->manage_power && mpn) + info->manage_power(dev, 0); + else + usb_autopm_put_interface(dev->intf); + + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_stop); + +/*-------------------------------------------------------------------------*/ + +// posts reads, and enables write queuing + +// precondition: never called in_interrupt + +int usbnet_open (struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + int retval; + const struct driver_info *info = dev->driver_info; + + if ((retval = usb_autopm_get_interface(dev->intf)) < 0) { + netif_info(dev, ifup, dev->net, + "resumption fail (%d) usbnet usb-%s-%s, %s\n", + retval, + dev->udev->bus->bus_name, + dev->udev->devpath, + info->description); + goto done_nopm; + } + + // put into "known safe" state + if (info->reset && (retval = info->reset (dev)) < 0) { + netif_info(dev, ifup, dev->net, + "open reset fail (%d) usbnet usb-%s-%s, %s\n", + retval, + dev->udev->bus->bus_name, + dev->udev->devpath, + info->description); + goto done; + } + + /* hard_mtu or rx_urb_size may change in reset() */ + usbnet_update_max_qlen(dev); + + // insist peer be connected + if (info->check_connect && (retval = info->check_connect (dev)) < 0) { + netif_err(dev, ifup, dev->net, "can't open; %d\n", retval); + goto done; + } + + /* start any status interrupt transfer */ + if (dev->interrupt) { + retval = usbnet_status_start(dev, GFP_KERNEL); + if (retval < 0) { + netif_err(dev, ifup, dev->net, + "intr submit %d\n", retval); + goto done; + } + } + + set_bit(EVENT_DEV_OPEN, &dev->flags); + netif_start_queue (net); + netif_info(dev, ifup, dev->net, + "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n", + (int)RX_QLEN(dev), (int)TX_QLEN(dev), + dev->net->mtu, + (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" : + (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" : + (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" : + (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" : + (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" : + "simple"); + + /* reset rx error state */ + dev->pkt_cnt = 0; + dev->pkt_err = 0; + clear_bit(EVENT_RX_KILL, &dev->flags); + + // delay posting reads until we're fully open + tasklet_schedule (&dev->bh); + if (info->manage_power) { + retval = info->manage_power(dev, 1); + if (retval < 0) { + retval = 0; + set_bit(EVENT_NO_RUNTIME_PM, &dev->flags); + } else { + usb_autopm_put_interface(dev->intf); + } + } + return retval; +done: + usb_autopm_put_interface(dev->intf); +done_nopm: + return retval; +} +EXPORT_SYMBOL_GPL(usbnet_open); + +/*-------------------------------------------------------------------------*/ + +/* ethtool methods; minidrivers may need to add some more, but + * they'll probably want to use this base set. + */ + +/* These methods are written on the assumption that the device + * uses MII + */ +int usbnet_get_link_ksettings_mii(struct net_device *net, + struct ethtool_link_ksettings *cmd) +{ + struct usbnet *dev = netdev_priv(net); + + if (!dev->mii.mdio_read) + return -EOPNOTSUPP; + + mii_ethtool_get_link_ksettings(&dev->mii, cmd); + + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii); + +int usbnet_get_link_ksettings_internal(struct net_device *net, + struct ethtool_link_ksettings *cmd) +{ + struct usbnet *dev = netdev_priv(net); + + /* the assumption that speed is equal on tx and rx + * is deeply engrained into the networking layer. + * For wireless stuff it is not true. + * We assume that rx_speed matters more. + */ + if (dev->rx_speed != SPEED_UNSET) + cmd->base.speed = dev->rx_speed / 1000000; + else if (dev->tx_speed != SPEED_UNSET) + cmd->base.speed = dev->tx_speed / 1000000; + else + cmd->base.speed = SPEED_UNKNOWN; + + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal); + +int usbnet_set_link_ksettings_mii(struct net_device *net, + const struct ethtool_link_ksettings *cmd) +{ + struct usbnet *dev = netdev_priv(net); + int retval; + + if (!dev->mii.mdio_write) + return -EOPNOTSUPP; + + retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd); + + /* link speed/duplex might have changed */ + if (dev->driver_info->link_reset) + dev->driver_info->link_reset(dev); + + /* hard_mtu or rx_urb_size may change in link_reset() */ + usbnet_update_max_qlen(dev); + + return retval; +} +EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii); + +u32 usbnet_get_link (struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + + /* If a check_connect is defined, return its result */ + if (dev->driver_info->check_connect) + return dev->driver_info->check_connect (dev) == 0; + + /* if the device has mii operations, use those */ + if (dev->mii.mdio_read) + return mii_link_ok(&dev->mii); + + /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */ + return ethtool_op_get_link(net); +} +EXPORT_SYMBOL_GPL(usbnet_get_link); + +int usbnet_nway_reset(struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + + if (!dev->mii.mdio_write) + return -EOPNOTSUPP; + + return mii_nway_restart(&dev->mii); +} +EXPORT_SYMBOL_GPL(usbnet_nway_reset); + +void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info) +{ + struct usbnet *dev = netdev_priv(net); + + strscpy(info->driver, dev->driver_name, sizeof(info->driver)); + strscpy(info->fw_version, dev->driver_info->description, + sizeof(info->fw_version)); + usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info); +} +EXPORT_SYMBOL_GPL(usbnet_get_drvinfo); + +u32 usbnet_get_msglevel (struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + + return dev->msg_enable; +} +EXPORT_SYMBOL_GPL(usbnet_get_msglevel); + +void usbnet_set_msglevel (struct net_device *net, u32 level) +{ + struct usbnet *dev = netdev_priv(net); + + dev->msg_enable = level; +} +EXPORT_SYMBOL_GPL(usbnet_set_msglevel); + +/* drivers may override default ethtool_ops in their bind() routine */ +static const struct ethtool_ops usbnet_ethtool_ops = { + .get_link = usbnet_get_link, + .nway_reset = usbnet_nway_reset, + .get_drvinfo = usbnet_get_drvinfo, + .get_msglevel = usbnet_get_msglevel, + .set_msglevel = usbnet_set_msglevel, + .get_ts_info = ethtool_op_get_ts_info, + .get_link_ksettings = usbnet_get_link_ksettings_mii, + .set_link_ksettings = usbnet_set_link_ksettings_mii, +}; + +/*-------------------------------------------------------------------------*/ + +static void __handle_link_change(struct usbnet *dev) +{ + if (!test_bit(EVENT_DEV_OPEN, &dev->flags)) + return; + + if (!netif_carrier_ok(dev->net)) { + /* kill URBs for reading packets to save bus bandwidth */ + unlink_urbs(dev, &dev->rxq); + + /* + * tx_timeout will unlink URBs for sending packets and + * tx queue is stopped by netcore after link becomes off + */ + } else { + /* submitting URBs for reading packets */ + tasklet_schedule(&dev->bh); + } + + /* hard_mtu or rx_urb_size may change during link change */ + usbnet_update_max_qlen(dev); + + clear_bit(EVENT_LINK_CHANGE, &dev->flags); +} + +void usbnet_set_rx_mode(struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + + usbnet_defer_kevent(dev, EVENT_SET_RX_MODE); +} +EXPORT_SYMBOL_GPL(usbnet_set_rx_mode); + +static void __handle_set_rx_mode(struct usbnet *dev) +{ + if (dev->driver_info->set_rx_mode) + (dev->driver_info->set_rx_mode)(dev); + + clear_bit(EVENT_SET_RX_MODE, &dev->flags); +} + +/* work that cannot be done in interrupt context uses keventd. + * + * NOTE: with 2.5 we could do more of this using completion callbacks, + * especially now that control transfers can be queued. + */ +static void +usbnet_deferred_kevent (struct work_struct *work) +{ + struct usbnet *dev = + container_of(work, struct usbnet, kevent); + int status; + + /* usb_clear_halt() needs a thread context */ + if (test_bit (EVENT_TX_HALT, &dev->flags)) { + unlink_urbs (dev, &dev->txq); + status = usb_autopm_get_interface(dev->intf); + if (status < 0) + goto fail_pipe; + status = usb_clear_halt (dev->udev, dev->out); + usb_autopm_put_interface(dev->intf); + if (status < 0 && + status != -EPIPE && + status != -ESHUTDOWN) { + if (netif_msg_tx_err (dev)) +fail_pipe: + netdev_err(dev->net, "can't clear tx halt, status %d\n", + status); + } else { + clear_bit (EVENT_TX_HALT, &dev->flags); + if (status != -ESHUTDOWN) + netif_wake_queue (dev->net); + } + } + if (test_bit (EVENT_RX_HALT, &dev->flags)) { + unlink_urbs (dev, &dev->rxq); + status = usb_autopm_get_interface(dev->intf); + if (status < 0) + goto fail_halt; + status = usb_clear_halt (dev->udev, dev->in); + usb_autopm_put_interface(dev->intf); + if (status < 0 && + status != -EPIPE && + status != -ESHUTDOWN) { + if (netif_msg_rx_err (dev)) +fail_halt: + netdev_err(dev->net, "can't clear rx halt, status %d\n", + status); + } else { + clear_bit (EVENT_RX_HALT, &dev->flags); + tasklet_schedule (&dev->bh); + } + } + + /* tasklet could resubmit itself forever if memory is tight */ + if (test_bit (EVENT_RX_MEMORY, &dev->flags)) { + struct urb *urb = NULL; + int resched = 1; + + if (netif_running (dev->net)) + urb = usb_alloc_urb (0, GFP_KERNEL); + else + clear_bit (EVENT_RX_MEMORY, &dev->flags); + if (urb != NULL) { + clear_bit (EVENT_RX_MEMORY, &dev->flags); + status = usb_autopm_get_interface(dev->intf); + if (status < 0) { + usb_free_urb(urb); + goto fail_lowmem; + } + if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK) + resched = 0; + usb_autopm_put_interface(dev->intf); +fail_lowmem: + if (resched) + tasklet_schedule (&dev->bh); + } + } + + if (test_bit (EVENT_LINK_RESET, &dev->flags)) { + const struct driver_info *info = dev->driver_info; + int retval = 0; + + clear_bit (EVENT_LINK_RESET, &dev->flags); + status = usb_autopm_get_interface(dev->intf); + if (status < 0) + goto skip_reset; + if(info->link_reset && (retval = info->link_reset(dev)) < 0) { + usb_autopm_put_interface(dev->intf); +skip_reset: + netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n", + retval, + dev->udev->bus->bus_name, + dev->udev->devpath, + info->description); + } else { + usb_autopm_put_interface(dev->intf); + } + + /* handle link change from link resetting */ + __handle_link_change(dev); + } + + if (test_bit (EVENT_LINK_CHANGE, &dev->flags)) + __handle_link_change(dev); + + if (test_bit (EVENT_SET_RX_MODE, &dev->flags)) + __handle_set_rx_mode(dev); + + + if (dev->flags) + netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags); +} + +/*-------------------------------------------------------------------------*/ + +static void tx_complete (struct urb *urb) +{ + struct sk_buff *skb = (struct sk_buff *) urb->context; + struct skb_data *entry = (struct skb_data *) skb->cb; + struct usbnet *dev = entry->dev; + + if (urb->status == 0) { + struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats); + unsigned long flags; + + flags = u64_stats_update_begin_irqsave(&stats64->syncp); + u64_stats_add(&stats64->tx_packets, entry->packets); + u64_stats_add(&stats64->tx_bytes, entry->length); + u64_stats_update_end_irqrestore(&stats64->syncp, flags); + } else { + dev->net->stats.tx_errors++; + + switch (urb->status) { + case -EPIPE: + usbnet_defer_kevent (dev, EVENT_TX_HALT); + break; + + /* software-driven interface shutdown */ + case -ECONNRESET: // async unlink + case -ESHUTDOWN: // hardware gone + break; + + /* like rx, tx gets controller i/o faults during hub_wq + * delays and so it uses the same throttling mechanism. + */ + case -EPROTO: + case -ETIME: + case -EILSEQ: + usb_mark_last_busy(dev->udev); + if (!timer_pending (&dev->delay)) { + mod_timer (&dev->delay, + jiffies + THROTTLE_JIFFIES); + netif_dbg(dev, link, dev->net, + "tx throttle %d\n", urb->status); + } + netif_stop_queue (dev->net); + break; + default: + netif_dbg(dev, tx_err, dev->net, + "tx err %d\n", entry->urb->status); + break; + } + } + + usb_autopm_put_interface_async(dev->intf); + (void) defer_bh(dev, skb, &dev->txq, tx_done); +} + +/*-------------------------------------------------------------------------*/ + +void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue) +{ + struct usbnet *dev = netdev_priv(net); + + unlink_urbs (dev, &dev->txq); + tasklet_schedule (&dev->bh); + /* this needs to be handled individually because the generic layer + * doesn't know what is sufficient and could not restore private + * information if a remedy of an unconditional reset were used. + */ + if (dev->driver_info->recover) + (dev->driver_info->recover)(dev); +} +EXPORT_SYMBOL_GPL(usbnet_tx_timeout); + +/*-------------------------------------------------------------------------*/ + +static int build_dma_sg(const struct sk_buff *skb, struct urb *urb) +{ + unsigned num_sgs, total_len = 0; + int i, s = 0; + + num_sgs = skb_shinfo(skb)->nr_frags + 1; + if (num_sgs == 1) + return 0; + + /* reserve one for zero packet */ + urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist), + GFP_ATOMIC); + if (!urb->sg) + return -ENOMEM; + + urb->num_sgs = num_sgs; + sg_init_table(urb->sg, urb->num_sgs + 1); + + sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb)); + total_len += skb_headlen(skb); + + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + skb_frag_t *f = &skb_shinfo(skb)->frags[i]; + + total_len += skb_frag_size(f); + sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f), + skb_frag_off(f)); + } + urb->transfer_buffer_length = total_len; + + return 1; +} + +netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, + struct net_device *net) +{ + struct usbnet *dev = netdev_priv(net); + unsigned int length; + struct urb *urb = NULL; + struct skb_data *entry; + const struct driver_info *info = dev->driver_info; + unsigned long flags; + int retval; + + if (skb) + skb_tx_timestamp(skb); + + // some devices want funky USB-level framing, for + // win32 driver (usually) and/or hardware quirks + if (info->tx_fixup) { + skb = info->tx_fixup (dev, skb, GFP_ATOMIC); + if (!skb) { + /* packet collected; minidriver waiting for more */ + if (info->flags & FLAG_MULTI_PACKET) + goto not_drop; + netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n"); + goto drop; + } + } + + if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) { + netif_dbg(dev, tx_err, dev->net, "no urb\n"); + goto drop; + } + + entry = (struct skb_data *) skb->cb; + entry->urb = urb; + entry->dev = dev; + + usb_fill_bulk_urb (urb, dev->udev, dev->out, + skb->data, skb->len, tx_complete, skb); + if (dev->can_dma_sg) { + if (build_dma_sg(skb, urb) < 0) + goto drop; + } + length = urb->transfer_buffer_length; + + /* don't assume the hardware handles USB_ZERO_PACKET + * NOTE: strictly conforming cdc-ether devices should expect + * the ZLP here, but ignore the one-byte packet. + * NOTE2: CDC NCM specification is different from CDC ECM when + * handling ZLP/short packets, so cdc_ncm driver will make short + * packet itself if needed. + */ + if (length % dev->maxpacket == 0) { + if (!(info->flags & FLAG_SEND_ZLP)) { + if (!(info->flags & FLAG_MULTI_PACKET)) { + length++; + if (skb_tailroom(skb) && !urb->num_sgs) { + skb->data[skb->len] = 0; + __skb_put(skb, 1); + } else if (urb->num_sgs) + sg_set_buf(&urb->sg[urb->num_sgs++], + dev->padding_pkt, 1); + } + } else + urb->transfer_flags |= URB_ZERO_PACKET; + } + urb->transfer_buffer_length = length; + + if (info->flags & FLAG_MULTI_PACKET) { + /* Driver has set number of packets and a length delta. + * Calculate the complete length and ensure that it's + * positive. + */ + entry->length += length; + if (WARN_ON_ONCE(entry->length <= 0)) + entry->length = length; + } else { + usbnet_set_skb_tx_stats(skb, 1, length); + } + + spin_lock_irqsave(&dev->txq.lock, flags); + retval = usb_autopm_get_interface_async(dev->intf); + if (retval < 0) { + spin_unlock_irqrestore(&dev->txq.lock, flags); + goto drop; + } + if (netif_queue_stopped(net)) { + usb_autopm_put_interface_async(dev->intf); + spin_unlock_irqrestore(&dev->txq.lock, flags); + goto drop; + } + +#ifdef CONFIG_PM + /* if this triggers the device is still a sleep */ + if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) { + /* transmission will be done in resume */ + usb_anchor_urb(urb, &dev->deferred); + /* no use to process more packets */ + netif_stop_queue(net); + usb_put_urb(urb); + spin_unlock_irqrestore(&dev->txq.lock, flags); + netdev_dbg(dev->net, "Delaying transmission for resumption\n"); + goto deferred; + } +#endif + + switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) { + case -EPIPE: + netif_stop_queue (net); + usbnet_defer_kevent (dev, EVENT_TX_HALT); + usb_autopm_put_interface_async(dev->intf); + break; + default: + usb_autopm_put_interface_async(dev->intf); + netif_dbg(dev, tx_err, dev->net, + "tx: submit urb err %d\n", retval); + break; + case 0: + netif_trans_update(net); + __usbnet_queue_skb(&dev->txq, skb, tx_start); + if (dev->txq.qlen >= TX_QLEN (dev)) + netif_stop_queue (net); + } + spin_unlock_irqrestore (&dev->txq.lock, flags); + + if (retval) { + netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval); +drop: + dev->net->stats.tx_dropped++; +not_drop: + if (skb) + dev_kfree_skb_any (skb); + if (urb) { + kfree(urb->sg); + usb_free_urb(urb); + } + } else + netif_dbg(dev, tx_queued, dev->net, + "> tx, len %u, type 0x%x\n", length, skb->protocol); +#ifdef CONFIG_PM +deferred: +#endif + return NETDEV_TX_OK; +} +EXPORT_SYMBOL_GPL(usbnet_start_xmit); + +static int rx_alloc_submit(struct usbnet *dev, gfp_t flags) +{ + struct urb *urb; + int i; + int ret = 0; + + /* don't refill the queue all at once */ + for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) { + urb = usb_alloc_urb(0, flags); + if (urb != NULL) { + ret = rx_submit(dev, urb, flags); + if (ret) + goto err; + } else { + ret = -ENOMEM; + goto err; + } + } +err: + return ret; +} + +/*-------------------------------------------------------------------------*/ + +// tasklet (work deferred from completions, in_irq) or timer + +static void usbnet_bh (struct timer_list *t) +{ + struct usbnet *dev = from_timer(dev, t, delay); + struct sk_buff *skb; + struct skb_data *entry; + + while ((skb = skb_dequeue (&dev->done))) { + entry = (struct skb_data *) skb->cb; + switch (entry->state) { + case rx_done: + entry->state = rx_cleanup; + rx_process (dev, skb); + continue; + case tx_done: + kfree(entry->urb->sg); + fallthrough; + case rx_cleanup: + usb_free_urb (entry->urb); + dev_kfree_skb (skb); + continue; + default: + netdev_dbg(dev->net, "bogus skb state %d\n", entry->state); + } + } + + /* restart RX again after disabling due to high error rate */ + clear_bit(EVENT_RX_KILL, &dev->flags); + + /* waiting for all pending urbs to complete? + * only then can we forgo submitting anew + */ + if (waitqueue_active(&dev->wait)) { + if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0) + wake_up_all(&dev->wait); + + // or are we maybe short a few urbs? + } else if (netif_running (dev->net) && + netif_device_present (dev->net) && + netif_carrier_ok(dev->net) && + !timer_pending(&dev->delay) && + !test_bit(EVENT_RX_PAUSED, &dev->flags) && + !test_bit(EVENT_RX_HALT, &dev->flags)) { + int temp = dev->rxq.qlen; + + if (temp < RX_QLEN(dev)) { + if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK) + return; + if (temp != dev->rxq.qlen) + netif_dbg(dev, link, dev->net, + "rxqlen %d --> %d\n", + temp, dev->rxq.qlen); + if (dev->rxq.qlen < RX_QLEN(dev)) + tasklet_schedule (&dev->bh); + } + if (dev->txq.qlen < TX_QLEN (dev)) + netif_wake_queue (dev->net); + } +} + +static void usbnet_bh_tasklet(struct tasklet_struct *t) +{ + struct usbnet *dev = from_tasklet(dev, t, bh); + + usbnet_bh(&dev->delay); +} + + +/*------------------------------------------------------------------------- + * + * USB Device Driver support + * + *-------------------------------------------------------------------------*/ + +// precondition: never called in_interrupt + +void usbnet_disconnect (struct usb_interface *intf) +{ + struct usbnet *dev; + struct usb_device *xdev; + struct net_device *net; + struct urb *urb; + + dev = usb_get_intfdata(intf); + usb_set_intfdata(intf, NULL); + if (!dev) + return; + + xdev = interface_to_usbdev (intf); + + netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n", + intf->dev.driver->name, + xdev->bus->bus_name, xdev->devpath, + dev->driver_info->description); + + net = dev->net; + unregister_netdev (net); + + while ((urb = usb_get_from_anchor(&dev->deferred))) { + dev_kfree_skb(urb->context); + kfree(urb->sg); + usb_free_urb(urb); + } + + if (dev->driver_info->unbind) + dev->driver_info->unbind(dev, intf); + + usb_kill_urb(dev->interrupt); + usb_free_urb(dev->interrupt); + kfree(dev->padding_pkt); + + free_percpu(net->tstats); + free_netdev(net); +} +EXPORT_SYMBOL_GPL(usbnet_disconnect); + +static const struct net_device_ops usbnet_netdev_ops = { + .ndo_open = usbnet_open, + .ndo_stop = usbnet_stop, + .ndo_start_xmit = usbnet_start_xmit, + .ndo_tx_timeout = usbnet_tx_timeout, + .ndo_set_rx_mode = usbnet_set_rx_mode, + .ndo_change_mtu = usbnet_change_mtu, + .ndo_get_stats64 = dev_get_tstats64, + .ndo_set_mac_address = eth_mac_addr, + .ndo_validate_addr = eth_validate_addr, +}; + +/*-------------------------------------------------------------------------*/ + +// precondition: never called in_interrupt + +static struct device_type wlan_type = { + .name = "wlan", +}; + +static struct device_type wwan_type = { + .name = "wwan", +}; + +int +usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) +{ + struct usbnet *dev; + struct net_device *net; + struct usb_host_interface *interface; + const struct driver_info *info; + struct usb_device *xdev; + int status; + const char *name; + struct usb_driver *driver = to_usb_driver(udev->dev.driver); + + /* usbnet already took usb runtime pm, so have to enable the feature + * for usb interface, otherwise usb_autopm_get_interface may return + * failure if RUNTIME_PM is enabled. + */ + if (!driver->supports_autosuspend) { + driver->supports_autosuspend = 1; + pm_runtime_enable(&udev->dev); + } + + name = udev->dev.driver->name; + info = (const struct driver_info *) prod->driver_info; + if (!info) { + dev_dbg (&udev->dev, "blacklisted by %s\n", name); + return -ENODEV; + } + xdev = interface_to_usbdev (udev); + interface = udev->cur_altsetting; + + status = -ENOMEM; + + // set up our own records + net = alloc_etherdev(sizeof(*dev)); + if (!net) + goto out; + + /* netdev_printk() needs this so do it as early as possible */ + SET_NETDEV_DEV(net, &udev->dev); + + dev = netdev_priv(net); + dev->udev = xdev; + dev->intf = udev; + dev->driver_info = info; + dev->driver_name = name; + dev->rx_speed = SPEED_UNSET; + dev->tx_speed = SPEED_UNSET; + + net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); + if (!net->tstats) + goto out0; + + dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV + | NETIF_MSG_PROBE | NETIF_MSG_LINK); + init_waitqueue_head(&dev->wait); + skb_queue_head_init (&dev->rxq); + skb_queue_head_init (&dev->txq); + skb_queue_head_init (&dev->done); + skb_queue_head_init(&dev->rxq_pause); + tasklet_setup(&dev->bh, usbnet_bh_tasklet); + INIT_WORK (&dev->kevent, usbnet_deferred_kevent); + init_usb_anchor(&dev->deferred); + timer_setup(&dev->delay, usbnet_bh, 0); + mutex_init (&dev->phy_mutex); + mutex_init(&dev->interrupt_mutex); + dev->interrupt_count = 0; + + dev->net = net; + strscpy(net->name, "usb%d", sizeof(net->name)); + eth_hw_addr_set(net, node_id); + + /* rx and tx sides can use different message sizes; + * bind() should set rx_urb_size in that case. + */ + dev->hard_mtu = net->mtu + net->hard_header_len; + net->min_mtu = 0; + net->max_mtu = ETH_MAX_MTU; + + net->netdev_ops = &usbnet_netdev_ops; + net->watchdog_timeo = TX_TIMEOUT_JIFFIES; + net->ethtool_ops = &usbnet_ethtool_ops; + + // allow device-specific bind/init procedures + // NOTE net->name still not usable ... + if (info->bind) { + status = info->bind (dev, udev); + if (status < 0) + goto out1; + + // heuristic: "usb%d" for links we know are two-host, + // else "eth%d" when there's reasonable doubt. userspace + // can rename the link if it knows better. + if ((dev->driver_info->flags & FLAG_ETHER) != 0 && + ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 || + (net->dev_addr [0] & 0x02) == 0)) + strscpy(net->name, "eth%d", sizeof(net->name)); + /* WLAN devices should always be named "wlan%d" */ + if ((dev->driver_info->flags & FLAG_WLAN) != 0) + strscpy(net->name, "wlan%d", sizeof(net->name)); + /* WWAN devices should always be named "wwan%d" */ + if ((dev->driver_info->flags & FLAG_WWAN) != 0) + strscpy(net->name, "wwan%d", sizeof(net->name)); + + /* devices that cannot do ARP */ + if ((dev->driver_info->flags & FLAG_NOARP) != 0) + net->flags |= IFF_NOARP; + + /* maybe the remote can't receive an Ethernet MTU */ + if (net->mtu > (dev->hard_mtu - net->hard_header_len)) + net->mtu = dev->hard_mtu - net->hard_header_len; + } else if (!info->in || !info->out) + status = usbnet_get_endpoints (dev, udev); + else { + u8 ep_addrs[3] = { + info->in + USB_DIR_IN, info->out + USB_DIR_OUT, 0 + }; + + dev->in = usb_rcvbulkpipe (xdev, info->in); + dev->out = usb_sndbulkpipe (xdev, info->out); + if (!(info->flags & FLAG_NO_SETINT)) + status = usb_set_interface (xdev, + interface->desc.bInterfaceNumber, + interface->desc.bAlternateSetting); + else + status = 0; + + if (status == 0 && !usb_check_bulk_endpoints(udev, ep_addrs)) + status = -EINVAL; + } + if (status >= 0 && dev->status) + status = init_status (dev, udev); + if (status < 0) + goto out3; + + if (!dev->rx_urb_size) + dev->rx_urb_size = dev->hard_mtu; + dev->maxpacket = usb_maxpacket(dev->udev, dev->out); + if (dev->maxpacket == 0) { + /* that is a broken device */ + status = -ENODEV; + goto out4; + } + + /* let userspace know we have a random address */ + if (ether_addr_equal(net->dev_addr, node_id)) + net->addr_assign_type = NET_ADDR_RANDOM; + + if ((dev->driver_info->flags & FLAG_WLAN) != 0) + SET_NETDEV_DEVTYPE(net, &wlan_type); + if ((dev->driver_info->flags & FLAG_WWAN) != 0) + SET_NETDEV_DEVTYPE(net, &wwan_type); + + /* initialize max rx_qlen and tx_qlen */ + usbnet_update_max_qlen(dev); + + if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) && + !(info->flags & FLAG_MULTI_PACKET)) { + dev->padding_pkt = kzalloc(1, GFP_KERNEL); + if (!dev->padding_pkt) { + status = -ENOMEM; + goto out4; + } + } + + status = register_netdev (net); + if (status) + goto out5; + netif_info(dev, probe, dev->net, + "register '%s' at usb-%s-%s, %s, %pM\n", + udev->dev.driver->name, + xdev->bus->bus_name, xdev->devpath, + dev->driver_info->description, + net->dev_addr); + + // ok, it's ready to go. + usb_set_intfdata (udev, dev); + + netif_device_attach (net); + + if (dev->driver_info->flags & FLAG_LINK_INTR) + usbnet_link_change(dev, 0, 0); + + return 0; + +out5: + kfree(dev->padding_pkt); +out4: + usb_free_urb(dev->interrupt); +out3: + if (info->unbind) + info->unbind (dev, udev); +out1: + /* subdrivers must undo all they did in bind() if they + * fail it, but we may fail later and a deferred kevent + * may trigger an error resubmitting itself and, worse, + * schedule a timer. So we kill it all just in case. + */ + cancel_work_sync(&dev->kevent); + del_timer_sync(&dev->delay); + free_percpu(net->tstats); +out0: + free_netdev(net); +out: + return status; +} +EXPORT_SYMBOL_GPL(usbnet_probe); + +/*-------------------------------------------------------------------------*/ + +/* + * suspend the whole driver as soon as the first interface is suspended + * resume only when the last interface is resumed + */ + +int usbnet_suspend (struct usb_interface *intf, pm_message_t message) +{ + struct usbnet *dev = usb_get_intfdata(intf); + + if (!dev->suspend_count++) { + spin_lock_irq(&dev->txq.lock); + /* don't autosuspend while transmitting */ + if (dev->txq.qlen && PMSG_IS_AUTO(message)) { + dev->suspend_count--; + spin_unlock_irq(&dev->txq.lock); + return -EBUSY; + } else { + set_bit(EVENT_DEV_ASLEEP, &dev->flags); + spin_unlock_irq(&dev->txq.lock); + } + /* + * accelerate emptying of the rx and queues, to avoid + * having everything error out. + */ + netif_device_detach (dev->net); + usbnet_terminate_urbs(dev); + __usbnet_status_stop_force(dev); + + /* + * reattach so runtime management can use and + * wake the device + */ + netif_device_attach (dev->net); + } + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_suspend); + +int usbnet_resume (struct usb_interface *intf) +{ + struct usbnet *dev = usb_get_intfdata(intf); + struct sk_buff *skb; + struct urb *res; + int retval; + + if (!--dev->suspend_count) { + /* resume interrupt URB if it was previously submitted */ + __usbnet_status_start_force(dev, GFP_NOIO); + + spin_lock_irq(&dev->txq.lock); + while ((res = usb_get_from_anchor(&dev->deferred))) { + + skb = (struct sk_buff *)res->context; + retval = usb_submit_urb(res, GFP_ATOMIC); + if (retval < 0) { + dev_kfree_skb_any(skb); + kfree(res->sg); + usb_free_urb(res); + usb_autopm_put_interface_async(dev->intf); + } else { + netif_trans_update(dev->net); + __skb_queue_tail(&dev->txq, skb); + } + } + + smp_mb(); + clear_bit(EVENT_DEV_ASLEEP, &dev->flags); + spin_unlock_irq(&dev->txq.lock); + + if (test_bit(EVENT_DEV_OPEN, &dev->flags)) { + /* handle remote wakeup ASAP + * we cannot race against stop + */ + if (netif_device_present(dev->net) && + !timer_pending(&dev->delay) && + !test_bit(EVENT_RX_HALT, &dev->flags)) + rx_alloc_submit(dev, GFP_NOIO); + + if (!(dev->txq.qlen >= TX_QLEN(dev))) + netif_tx_wake_all_queues(dev->net); + tasklet_schedule (&dev->bh); + } + } + + if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) + usb_autopm_get_interface_no_resume(intf); + + return 0; +} +EXPORT_SYMBOL_GPL(usbnet_resume); + +/* + * Either a subdriver implements manage_power, then it is assumed to always + * be ready to be suspended or it reports the readiness to be suspended + * explicitly + */ +void usbnet_device_suggests_idle(struct usbnet *dev) +{ + if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) { + dev->intf->needs_remote_wakeup = 1; + usb_autopm_put_interface_async(dev->intf); + } +} +EXPORT_SYMBOL(usbnet_device_suggests_idle); + +/* + * For devices that can do without special commands + */ +int usbnet_manage_power(struct usbnet *dev, int on) +{ + dev->intf->needs_remote_wakeup = on; + return 0; +} +EXPORT_SYMBOL(usbnet_manage_power); + +void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset) +{ + /* update link after link is reseted */ + if (link && !need_reset) + netif_carrier_on(dev->net); + else + netif_carrier_off(dev->net); + + if (need_reset && link) + usbnet_defer_kevent(dev, EVENT_LINK_RESET); + else + usbnet_defer_kevent(dev, EVENT_LINK_CHANGE); +} +EXPORT_SYMBOL(usbnet_link_change); + +/*-------------------------------------------------------------------------*/ +static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, void *data, u16 size) +{ + void *buf = NULL; + int err = -ENOMEM; + + netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x" + " value=0x%04x index=0x%04x size=%d\n", + cmd, reqtype, value, index, size); + + if (size) { + buf = kmalloc(size, GFP_NOIO); + if (!buf) + goto out; + } + + err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), + cmd, reqtype, value, index, buf, size, + USB_CTRL_GET_TIMEOUT); + if (err > 0 && err <= size) { + if (data) + memcpy(data, buf, err); + else + netdev_dbg(dev->net, + "Huh? Data requested but thrown away.\n"); + } + kfree(buf); +out: + return err; +} + +static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, const void *data, + u16 size) +{ + void *buf = NULL; + int err = -ENOMEM; + + netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x" + " value=0x%04x index=0x%04x size=%d\n", + cmd, reqtype, value, index, size); + + if (data) { + buf = kmemdup(data, size, GFP_NOIO); + if (!buf) + goto out; + } else { + if (size) { + WARN_ON_ONCE(1); + err = -EINVAL; + goto out; + } + } + + err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), + cmd, reqtype, value, index, buf, size, + USB_CTRL_SET_TIMEOUT); + kfree(buf); + +out: + return err; +} + +/* + * The function can't be called inside suspend/resume callback, + * otherwise deadlock will be caused. + */ +int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, void *data, u16 size) +{ + int ret; + + if (usb_autopm_get_interface(dev->intf) < 0) + return -ENODEV; + ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index, + data, size); + usb_autopm_put_interface(dev->intf); + return ret; +} +EXPORT_SYMBOL_GPL(usbnet_read_cmd); + +/* + * The function can't be called inside suspend/resume callback, + * otherwise deadlock will be caused. + */ +int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, const void *data, u16 size) +{ + int ret; + + if (usb_autopm_get_interface(dev->intf) < 0) + return -ENODEV; + ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index, + data, size); + usb_autopm_put_interface(dev->intf); + return ret; +} +EXPORT_SYMBOL_GPL(usbnet_write_cmd); + +/* + * The function can be called inside suspend/resume callback safely + * and should only be called by suspend/resume callback generally. + */ +int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, void *data, u16 size) +{ + return __usbnet_read_cmd(dev, cmd, reqtype, value, index, + data, size); +} +EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm); + +/* + * The function can be called inside suspend/resume callback safely + * and should only be called by suspend/resume callback generally. + */ +int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, const void *data, + u16 size) +{ + return __usbnet_write_cmd(dev, cmd, reqtype, value, index, + data, size); +} +EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm); + +static void usbnet_async_cmd_cb(struct urb *urb) +{ + struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context; + int status = urb->status; + + if (status < 0) + dev_dbg(&urb->dev->dev, "%s failed with %d", + __func__, status); + + kfree(req); + usb_free_urb(urb); +} + +/* + * The caller must make sure that device can't be put into suspend + * state until the control URB completes. + */ +int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype, + u16 value, u16 index, const void *data, u16 size) +{ + struct usb_ctrlrequest *req; + struct urb *urb; + int err = -ENOMEM; + void *buf = NULL; + + netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x" + " value=0x%04x index=0x%04x size=%d\n", + cmd, reqtype, value, index, size); + + urb = usb_alloc_urb(0, GFP_ATOMIC); + if (!urb) + goto fail; + + if (data) { + buf = kmemdup(data, size, GFP_ATOMIC); + if (!buf) { + netdev_err(dev->net, "Error allocating buffer" + " in %s!\n", __func__); + goto fail_free_urb; + } + } + + req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC); + if (!req) + goto fail_free_buf; + + req->bRequestType = reqtype; + req->bRequest = cmd; + req->wValue = cpu_to_le16(value); + req->wIndex = cpu_to_le16(index); + req->wLength = cpu_to_le16(size); + + usb_fill_control_urb(urb, dev->udev, + usb_sndctrlpipe(dev->udev, 0), + (void *)req, buf, size, + usbnet_async_cmd_cb, req); + urb->transfer_flags |= URB_FREE_BUFFER; + + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err < 0) { + netdev_err(dev->net, "Error submitting the control" + " message: status=%d\n", err); + goto fail_free_all; + } + return 0; + +fail_free_all: + kfree(req); +fail_free_buf: + kfree(buf); + /* + * avoid a double free + * needed because the flag can be set only + * after filling the URB + */ + urb->transfer_flags = 0; +fail_free_urb: + usb_free_urb(urb); +fail: + return err; + +} +EXPORT_SYMBOL_GPL(usbnet_write_cmd_async); +/*-------------------------------------------------------------------------*/ + +static int __init usbnet_init(void) +{ + /* Compiler should optimize this out. */ + BUILD_BUG_ON( + sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data)); + + eth_random_addr(node_id); + return 0; +} +module_init(usbnet_init); + +static void __exit usbnet_exit(void) +{ +} +module_exit(usbnet_exit); + +MODULE_AUTHOR("David Brownell"); +MODULE_DESCRIPTION("USB network driver framework"); +MODULE_LICENSE("GPL"); |