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todevice.k.cc
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// -*- mode: c++; c-basic-offset: 4 -*-
/*
* todevice.{cc,hh} -- element sends packets to Linux devices.
* Robert Morris
* Eddie Kohler: register once per configuration
* Benjie Chen: polling
*
* Copyright (c) 1999-2000 Massachusetts Institute of Technology
* Copyright (c) 2000 Mazu Networks, Inc.
* Copyright (c) 2001 International Computer Science Institute
* Copyright (c) 2005-2007 Regents of the University of California
* Copyright (c) 2010 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, subject to the conditions
* listed in the Click LICENSE file. These conditions include: you must
* preserve this copyright notice, and you cannot mention the copyright
* holders in advertising related to the Software without their permission.
* The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
* notice is a summary of the Click LICENSE file; the license in that file is
* legally binding.
*/
#include <click/config.h>
#include <click/glue.hh>
#include "polldevice.hh"
#include "todevice.hh"
#include <click/error.hh>
#include <click/etheraddress.hh>
#include <click/args.hh>
#include <click/router.hh>
#include <click/standard/scheduleinfo.hh>
#include <click/straccum.hh>
#include <click/cxxprotect.h>
CLICK_CXX_PROTECT
#include <net/pkt_sched.h>
#include <net/dst.h>
CLICK_CXX_UNPROTECT
#include <click/cxxunprotect.h>
#if __i386__
#include <click/perfctr-i586.hh>
#endif
/* for watching when devices go offline */
static AnyDeviceMap to_device_map;
static struct notifier_block device_notifier;
extern "C" {
static int device_notifier_hook(struct notifier_block *nb, unsigned long val, void *v);
#if HAVE_CLICK_KERNEL_TX_NOTIFY
static struct notifier_block tx_notifier;
static int registered_tx_notifiers;
static int tx_notifier_hook(struct notifier_block *nb, unsigned long val, void *v);
#endif
}
void
ToDevice::static_initialize()
{
to_device_map.initialize();
#if HAVE_CLICK_KERNEL_TX_NOTIFY
tx_notifier.notifier_call = tx_notifier_hook;
tx_notifier.priority = 1;
tx_notifier.next = 0;
#endif
device_notifier.notifier_call = device_notifier_hook;
device_notifier.priority = 1;
device_notifier.next = 0;
register_netdevice_notifier(&device_notifier);
}
void
ToDevice::static_cleanup()
{
unregister_netdevice_notifier(&device_notifier);
#if HAVE_CLICK_KERNEL_TX_NOTIFY
if (registered_tx_notifiers)
unregister_net_tx(&tx_notifier);
#endif
}
inline void
ToDevice::tx_wake_queue(net_device *dev)
{
//click_chatter("%p{element}::%s for dev %s\n", this, __func__, dev->name);
_task.reschedule();
}
#if HAVE_CLICK_KERNEL_TX_NOTIFY
extern "C" {
static int
tx_notifier_hook(struct notifier_block *nb, unsigned long val, void *v)
{
struct net_device *dev = (struct net_device *)v;
if (!dev)
return 0;
unsigned long lock_flags;
to_device_map.lock(false, lock_flags);
AnyDevice *es[8];
int nes = to_device_map.lookup_all(dev, true, es, 8);
for (int i = 0; i < nes; i++)
((ToDevice *)(es[i]))->tx_wake_queue(dev);
to_device_map.unlock(false, lock_flags);
return 0;
}
}
#endif
ToDevice::ToDevice()
: _q(0), _no_pad(false)
{
}
ToDevice::~ToDevice()
{
}
int
ToDevice::configure(Vector<String> &conf, ErrorHandler *errh)
{
_burst = 16;
int tx_queue = 0;
if (AnyDevice::configure_keywords(conf, errh, false) < 0
|| (Args(conf, this, errh)
.read_mp("DEVNAME", _devname)
.read_p("BURST", _burst)
.read("NO_PAD", _no_pad)
.read("QUEUE", tx_queue)
.complete() < 0))
return -1;
#if !HAVE_NETDEV_GET_TX_QUEUE
if (tx_queue != 0)
return errh->error("the kernel only supports QUEUE 0");
#else
_tx_queue = tx_queue;
#endif
net_device *dev = lookup_device(errh);
#if HAVE_NETDEV_GET_TX_QUEUE
if (dev && _tx_queue >= dev->num_tx_queues) {
dev_put(dev);
dev = 0;
if (!allow_nonexistent())
return errh->error("device %<%s%> has only %d queues", _devname.c_str(), _tx_queue);
}
#endif
set_device(dev, &to_device_map, 0);
return errh->nerrors() ? -1 : 0;
}
int
ToDevice::initialize(ErrorHandler *errh)
{
if (AnyDevice::initialize_keywords(errh) < 0)
return -1;
// check for duplicate writers
if (ifindex() >= 0) {
StringAccum writer_name;
writer_name << "device_writer_" << ifindex() << "_" << _tx_queue;
void *&used = router()->force_attachment(writer_name.take_string());
if (used)
return errh->error("duplicate writer for device %<%s%>", _devname.c_str());
used = this;
}
#if HAVE_CLICK_KERNEL_TX_NOTIFY
if (!registered_tx_notifiers) {
tx_notifier.next = 0;
register_net_tx(&tx_notifier);
}
registered_tx_notifiers++;
#endif
ScheduleInfo::initialize_task(this, &_task, _dev != 0, errh);
_signal = Notifier::upstream_empty_signal(this, 0, &_task);
#if HAVE_STRIDE_SCHED
// user specifies max number of tickets; we start with default
_max_tickets = _task.tickets();
_task.set_tickets(Task::DEFAULT_TICKETS);
#endif
reset_counts();
return 0;
}
void
ToDevice::reset_counts()
{
_npackets = 0;
_busy_returns = 0;
_dev_idle = 0;
_hard_start = 0;
_too_short = 0;
_runs = 0;
_drops = 0;
_holds = 0;
_pulls = 0;
#if CLICK_DEVICE_STATS
_activations = 0;
_time_clean = 0;
_time_freeskb = 0;
_time_queue = 0;
_perfcnt1_pull = 0;
_perfcnt1_clean = 0;
_perfcnt1_freeskb = 0;
_perfcnt1_queue = 0;
_perfcnt2_pull = 0;
_perfcnt2_clean = 0;
_perfcnt2_freeskb = 0;
_perfcnt2_queue = 0;
#endif
#if CLICK_DEVICE_THESIS_STATS || CLICK_DEVICE_STATS
_pull_cycles = 0;
#endif
}
void
ToDevice::cleanup(CleanupStage stage)
{
#if HAVE_CLICK_KERNEL_TX_NOTIFY
if (stage >= CLEANUP_INITIALIZED) {
registered_tx_notifiers--;
if (registered_tx_notifiers == 0)
unregister_net_tx(&tx_notifier);
}
#endif
if (_q)
_q->kill();
clear_device(&to_device_map, 0);
}
/*
* Problem: Linux drivers aren't required to
* accept a packet even if they've marked themselves
* as idle. What do we do with a rejected packet?
*/
#if LINUX_VERSION_CODE < 0x020400
# define click_netif_tx_queue_stopped(dev, txq) ((dev)->tbusy)
# define click_netif_tx_wake_queue(dev, txq) mark_bh(NET_BH)
#elif HAVE_NETDEV_GET_TX_QUEUE
# define click_netif_tx_queue_stopped(dev, txq) netif_tx_queue_stopped((txq))
# define click_netif_tx_wake_queue(dev, txq) netif_tx_wake_queue((txq))
#else
# define click_netif_tx_queue_stopped(dev, txq) netif_queue_stopped((dev))
# define click_netif_tx_wake_queue(dev, txq) netif_wake_queue((dev))
#endif
#if HAVE_NETIF_TX_QUEUE_FROZEN
# define click_netif_tx_queue_frozen(txq) netif_tx_queue_frozen((txq))
#else
# define click_netif_tx_queue_frozen(txq) 0
#endif
#ifdef NETIF_F_LLTX
# define click_netif_needs_lock(dev) (((dev)->features & NETIF_F_LLTX) == 0)
#else
# define click_netif_needs_lock(dev) 1
#endif
#if HAVE_NETDEV_GET_TX_QUEUE
# define click_netif_lock(dev, txq) (txq)->_xmit_lock
# define click_netif_lock_owner(dev, txq) (txq)->xmit_lock_owner
#elif HAVE_NETIF_TX_LOCK
# define click_netif_lock(dev, txq) (dev)->_xmit_lock
# define click_netif_lock_owner(dev, txq) (dev)->xmit_lock_owner
#else
# define click_netif_lock(dev, txq) (dev)->xmit_lock
# define click_netif_lock_owner(dev, txq) (dev)->xmit_lock_owner
#endif
static bool
tx_trylock(struct net_device *dev, struct netdev_queue *txq) {
if (!click_netif_needs_lock(dev))
return true;
if (!spin_trylock_bh(&click_netif_lock(dev, txq)))
return false;
click_netif_lock_owner(dev, txq) = smp_processor_id();
return true;
}
static void
tx_unlock(struct net_device *dev, struct netdev_queue *txq) {
if (!click_netif_needs_lock(dev))
return;
#if HAVE_NETDEV_GET_TX_QUEUE
__netif_tx_unlock_bh(txq);
#elif HAVE_NETIF_TX_LOCK
netif_tx_unlock_bh(dev);
#else
dev->xmit_lock_owner = -1;
spin_unlock_bh(&dev->xmit_lock);
#endif
}
bool
ToDevice::run_task(Task *)
{
int busy = 0, sent = 0, ok;
struct net_device *dev = _dev;
++_runs;
#if HAVE_NETDEV_GET_TX_QUEUE
struct netdev_queue *txq = netdev_get_tx_queue(dev, _tx_queue);
#else
struct netdev_queue *txq = 0;
#endif
if (!tx_trylock(dev, txq)) {
_task.fast_reschedule();
return false;
}
#if CLICK_DEVICE_STATS
unsigned low00, low10;
uint64_t time_now;
SET_STATS(low00, low10, time_now);
#endif
#if HAVE_LINUX_POLLING
bool is_polling = (dev->polling > 0);
struct sk_buff *clean_skbs;
if (is_polling)
clean_skbs = dev->tx_clean(dev);
else
clean_skbs = 0;
#endif
/* try to send from click */
while (sent < _burst) {
busy = click_netif_tx_queue_stopped(dev, txq)
|| click_netif_tx_queue_frozen(txq);
if (busy != 0)
break;
#if CLICK_DEVICE_THESIS_STATS && !CLICK_DEVICE_STATS
click_cycles_t before_pull_cycles = click_get_cycles();
#endif
_pulls++;
Packet *p;
if ((p = _q)) {
_q = 0;
if (click_jiffies_less(_q_expiry_j, click_jiffies())) {
p->kill();
_drops++;
p = 0;
}
}
if (!p) {
tx_unlock(dev, txq);
p = input(0).pull();
if (!tx_trylock(dev, txq)) {
_task.reschedule();
_q = p;
_q_expiry_j = click_jiffies() + queue_timeout;
goto bail;
}
}
if (!p)
break;
#if CLICK_DEVICE_THESIS_STATS && !CLICK_DEVICE_STATS
_pull_cycles += click_get_cycles() - before_pull_cycles - CLICK_CYCLE_COMPENSATION;
#endif
GET_STATS_RESET(low00, low10, time_now,
_perfcnt1_pull, _perfcnt2_pull, _pull_cycles);
busy = queue_packet(p, txq);
GET_STATS_RESET(low00, low10, time_now,
_perfcnt1_queue, _perfcnt2_queue, _time_queue);
if (busy)
break;
sent++;
}
#if HAVE_LINUX_POLLING
if (is_polling && sent > 0)
dev->tx_eob(dev);
// If Linux tried to send a packet, but saw tbusy, it will
// have left it on the queue. It'll just sit there forever
// (or until Linux sends another packet) unless we poke
// net_bh(), which calls qdisc_restart(). We are not allowed
// to call qdisc_restart() ourselves, outside of net_bh().
if (is_polling && !busy && dev->qdisc->q.qlen) {
dev->tx_eob(dev);
click_netif_tx_wake_queue(dev, txq);
}
#endif
#if HAVE_LINUX_POLLING
if (is_polling) {
if (busy && sent == 0) {
_dev_idle++;
if (_dev_idle == 1024) {
/* device didn't send anything, ping it */
dev->tx_start(dev);
_dev_idle = 0;
_hard_start++;
}
} else
_dev_idle = 0;
}
#endif
tx_unlock(dev, txq);
bail:
#if CLICK_DEVICE_STATS
if (sent > 0)
_activations++;
#endif
if (busy && sent == 0)
_busy_returns++;
// If we're polling, never go to sleep! We're relying on ToDevice to clean
// the transmit ring.
// Otherwise, don't go to sleep if the signal isn't active and
// we didn't just send any packets
#if HAVE_CLICK_KERNEL_TX_NOTIFY
bool reschedule = (!busy && (sent > 0 || _signal.active()));
#else
bool reschedule = (busy || sent > 0 || _signal.active());
#endif
#if HAVE_LINUX_POLLING
if (is_polling) {
// 8.Dec.07: Do not recycle skbs until after unlocking the device, to
// avoid deadlock. After initial patch by Joonwoo Park.
if (clean_skbs) {
# if CLICK_DEVICE_STATS
if (_activations > 1)
GET_STATS_RESET(low00, low10, time_now,
_perfcnt1_clean, _perfcnt2_clean, _time_clean);
# endif
skbmgr_recycle_skbs(clean_skbs);
# if CLICK_DEVICE_STATS
if (_activations > 1)
GET_STATS_RESET(low00, low10, time_now,
_perfcnt1_freeskb, _perfcnt2_freeskb, _time_freeskb);
# endif
}
reschedule = true;
// 9/18/06: Frederic Van Quickenborne reports (1/24/05) that ticket
// adjustments in FromDevice+ToDevice cause odd behavior. The ticket
// adjustments actually don't feel necessary to me in From/ToDevice
// any more, as described in FromDevice. So adjusting tickets now
// only if polling.
adjust_tickets(sent);
}
#endif /* HAVE_LINUX_POLLING */
// 5.Feb.2007: Incorporate a version of a patch from Jason Park. If the
// device is "busy", perhaps there is no carrier! Don't spin on no
// carrier; instead, rely on Linux's notifer_hook to wake us up again.
if (busy && sent == 0 && !netif_carrier_ok(dev))
reschedule = false;
if (reschedule)
_task.fast_reschedule();
return sent > 0;
}
int
ToDevice::queue_packet(Packet *p, struct netdev_queue *txq)
{
struct sk_buff *skb1 = p->skb();
struct net_device *dev = _dev;
/*
* Ensure minimum ethernet packet size (14 hdr + 46 data).
* I can't figure out where Linux does this, so I don't
* know the correct procedure.
*/
int need_tail = 60 - p->length();
if (!_no_pad && need_tail > 0) {
if (skb_tailroom(skb1) < need_tail) {
if (++_too_short == 1)
printk("<1>ToDevice %s packet too small (len %d, tailroom %d, need %d), had to copy\n", dev->name, skb1->len, skb_tailroom(skb1), need_tail);
struct sk_buff *nskb = skb_copy_expand(skb1, skb_headroom(skb1), need_tail, GFP_ATOMIC);
kfree_skb(skb1);
if (!nskb)
return -1;
skb1 = nskb;
}
// printk("padding %d:%d:%d\n", skb1->truesize, skb1->len, 60-skb1->len);
memset(skb_put(skb1, need_tail), 0, need_tail);
}
// set the device annotation;
// apparently some devices in Linux 2.6 require it
skb1->dev = dev;
skb_set_queue_mapping(skb1, _tx_queue);
#ifdef IFF_XMIT_DST_RELEASE // true
/*
* If device doesnt need skb->dst, release it right now while
* its hot in this cpu cache
*/
if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
skb_dst_drop(skb1);
#endif
int ret;
#if HAVE_LINUX_POLLING // false
if (dev->polling > 0) {
ret = dev->tx_queue(dev, skb1);
goto enqueued;
}
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 30) // true
// logic here should mirror logic in linux/net/core/pktgen.c
ret = dev->netdev_ops->ndo_start_xmit(skb1, dev);
# if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 31) // true
if (ret == NETDEV_TX_OK)
txq_trans_update(txq);
# endif //LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 31)
# if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 33) // true
ret = !dev_xmit_complete(ret);
# else
if (unlikely(ret == NET_XMIT_DROP))
p = NULL;
# endif // LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 33)
#else
ret = dev->hard_start_xmit(skb1, dev);
#endif // LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 30)
++_hard_start;
enqueued:
if (ret != 0) {
_q = (Packet*)skb1;
_q_expiry_j = click_jiffies() + queue_timeout;
if (++_holds == 1)
printk("<1>ToDevice %s is full, packet delayed\n", dev->name);
} else
_npackets++;
return ret;
}
void
ToDevice::change_device(net_device *dev)
{
#if HAVE_NETDEV_GET_TX_QUEUE
if (dev && _tx_queue >= dev->num_tx_queues)
dev = 0;
#endif
bool dev_change = _dev != dev;
if (dev_change)
_task.strong_unschedule();
set_device(dev, &to_device_map, anydev_change);
if (dev_change && _dev)
_task.strong_reschedule();
else if (_dev && _carrier_ok)
_task.reschedule();
}
extern "C" {
static int
device_notifier_hook(struct notifier_block *nb, unsigned long flags, void *v)
{
#ifdef NETDEV_GOING_DOWN
if (flags == NETDEV_GOING_DOWN)
flags = NETDEV_DOWN;
#endif
if (flags == NETDEV_DOWN || flags == NETDEV_UP || flags == NETDEV_CHANGE) {
bool exists = (flags != NETDEV_UP);
net_device *dev = (net_device *)v;
unsigned long lock_flags;
to_device_map.lock(true, lock_flags);
AnyDevice *es[8];
int nes = to_device_map.lookup_all(dev, exists, es, 8);
for (int i = 0; i < nes; i++)
((ToDevice *)(es[i]))->change_device(flags == NETDEV_DOWN ? 0 : dev);
to_device_map.unlock(true, lock_flags);
}
return 0;
}
}
String
ToDevice::read_calls(Element *e, void *)
{
ToDevice *td = (ToDevice *)e;
StringAccum sa;
sa << td->_holds << " packets held\n"
<< td->_drops << " packets dropped\n"
<< td->_hard_start << " hard start xmit\n"
<< td->_busy_returns << " device busy returns\n"
<< td->_npackets << " packets sent\n"
<< td->_runs << " calls to run_task()\n"
<< td->_pulls << " pulls\n";
#if CLICK_DEVICE_STATS
sa << td->_pull_cycles << " cycles pull\n"
<< td->_time_clean << " cycles clean\n"
<< td->_time_freeskb << " cycles freeskb\n"
<< td->_time_queue << " cycles queue\n"
<< td->_perfcnt1_pull << " perfctr1 pull\n"
<< td->_perfcnt1_clean << " perfctr1 clean\n"
<< td->_perfcnt1_freeskb << " perfctr1 freeskb\n"
<< td->_perfcnt1_queue << " perfctr1 queue\n"
<< td->_perfcnt2_pull << " perfctr2 pull\n"
<< td->_perfcnt2_clean << " perfctr2 clean\n"
<< td->_perfcnt2_freeskb << " perfctr2 freeskb\n"
<< td->_perfcnt2_queue << " perfctr2 queue\n"
<< td->_activations << " transmit activations\n";
#endif
return sa.take_string();
}
int
ToDevice::write_handler(const String &, Element *e, void *, ErrorHandler *)
{
ToDevice *td = (ToDevice *)e;
td->reset_counts();
return 0;
}
void
ToDevice::add_handlers()
{
add_read_handler("calls", read_calls, 0);
add_data_handlers("count", Handler::f_read, &_npackets);
add_data_handlers("drops", Handler::f_read, &_drops);
add_data_handlers("holds", Handler::f_read, &_holds);
add_data_handlers("packets", Handler::f_read | Handler::f_deprecated, &_npackets);
#if CLICK_DEVICE_THESIS_STATS || CLICK_DEVICE_STATS
add_read_handler("pull_cycles", Handler::f_read, &_pull_cycles);
#endif
#if CLICK_DEVICE_STATS
add_read_handler("enqueue_cycles", Handler::f_read, &_time_queue);
add_read_handler("clean_dma_cycles", Handler::f_read, &_time_clean);
#endif
add_write_handler("reset_counts", write_handler, 0, Handler::f_button);
add_task_handlers(&_task);
}
ELEMENT_REQUIRES(AnyDevice linuxmodule)
EXPORT_ELEMENT(ToDevice)
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