Commit 9286ae01 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'sunvnet-napi'

Sowmini Varadhan says:

====================
sunvnet: NAPIfy sunvnet

This patchset converts the sunvnet driver to use the NAPI framework.
Changes since v4 to Patch1:
  vnet_event accumulates LDC_EVENT_* bits into rx_event.
  vnet_event_napi() unrolls send_events() logic to process all rx_event bits.
Changes since v5:
  Patch 1: use net_device.h definition for NAPI_POLL_WEIGHT.
  Drop sparclinux changes (patch3) per David Miller feedback

Patch 1 in the series addresses the packet-receive path- all
the vnet_event() processing is moved into NAPI context.
This patch is dependant on the sparc-next commit:
  "sparc64: Add vio_set_intr() to enable/disable Rx interrupts"
  (sparc commit id ca605b7d

)

Patch 2 uses RCU to fix race conditions between vnet_port_remove and
paths that access/modify port-related state, such as vnet_start_xmit.

Patch 3 leverages from the NAPIfied Rx path,
dropping superfluous usage of the irqsave/irqrestores on the vio.lock
where possible.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 132fb579 13b13dd9
......@@ -311,9 +311,7 @@ static int vnet_rx_one(struct vnet_port *port, unsigned int len,
dev->stats.rx_packets++;
dev->stats.rx_bytes += len;
netif_rx(skb);
napi_gro_receive(&port->napi, skb);
return 0;
out_free_skb:
......@@ -430,6 +428,7 @@ static int vnet_walk_rx_one(struct vnet_port *port,
struct vio_driver_state *vio = &port->vio;
int err;
BUG_ON(desc == NULL);
if (IS_ERR(desc))
return PTR_ERR(desc);
......@@ -456,10 +455,11 @@ static int vnet_walk_rx_one(struct vnet_port *port,
}
static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
u32 start, u32 end)
u32 start, u32 end, int *npkts, int budget)
{
struct vio_driver_state *vio = &port->vio;
int ack_start = -1, ack_end = -1;
bool send_ack = true;
end = (end == (u32) -1) ? prev_idx(start, dr) : next_idx(end, dr);
......@@ -471,6 +471,7 @@ static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
return err;
if (err != 0)
break;
(*npkts)++;
if (ack_start == -1)
ack_start = start;
ack_end = start;
......@@ -482,13 +483,26 @@ static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
return err;
ack_start = -1;
}
if ((*npkts) >= budget) {
send_ack = false;
break;
}
}
if (unlikely(ack_start == -1))
ack_start = ack_end = prev_idx(start, dr);
return vnet_send_ack(port, dr, ack_start, ack_end, VIO_DRING_STOPPED);
if (send_ack) {
port->napi_resume = false;
return vnet_send_ack(port, dr, ack_start, ack_end,
VIO_DRING_STOPPED);
} else {
port->napi_resume = true;
port->napi_stop_idx = ack_end;
return 1;
}
}
static int vnet_rx(struct vnet_port *port, void *msgbuf)
static int vnet_rx(struct vnet_port *port, void *msgbuf, int *npkts,
int budget)
{
struct vio_dring_data *pkt = msgbuf;
struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
......@@ -505,11 +519,13 @@ static int vnet_rx(struct vnet_port *port, void *msgbuf)
return 0;
}
dr->rcv_nxt++;
if (!port->napi_resume)
dr->rcv_nxt++;
/* XXX Validate pkt->start_idx and pkt->end_idx XXX */
return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx);
return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx,
npkts, budget);
}
static int idx_is_pending(struct vio_dring_state *dr, u32 end)
......@@ -542,9 +558,12 @@ static int vnet_ack(struct vnet_port *port, void *msgbuf)
if (unlikely(!idx_is_pending(dr, end)))
return 0;
vp = port->vp;
dev = vp->dev;
/* sync for race conditions with vnet_start_xmit() and tell xmit it
* is time to send a trigger.
*/
netif_tx_lock(dev);
dr->cons = next_idx(end, dr);
desc = vio_dring_entry(dr, dr->cons);
if (desc->hdr.state == VIO_DESC_READY && port->start_cons) {
......@@ -559,10 +578,8 @@ static int vnet_ack(struct vnet_port *port, void *msgbuf)
} else {
port->start_cons = true;
}
netif_tx_unlock(dev);
vp = port->vp;
dev = vp->dev;
if (unlikely(netif_queue_stopped(dev) &&
vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
return 1;
......@@ -591,9 +608,8 @@ static int handle_mcast(struct vnet_port *port, void *msgbuf)
return 0;
}
static void maybe_tx_wakeup(unsigned long param)
static void maybe_tx_wakeup(struct vnet *vp)
{
struct vnet *vp = (struct vnet *)param;
struct net_device *dev = vp->dev;
netif_tx_lock(dev);
......@@ -601,7 +617,8 @@ static void maybe_tx_wakeup(unsigned long param)
struct vnet_port *port;
int wake = 1;
list_for_each_entry(port, &vp->port_list, list) {
rcu_read_lock();
list_for_each_entry_rcu(port, &vp->port_list, list) {
struct vio_dring_state *dr;
dr = &port->vio.drings[VIO_DRIVER_TX_RING];
......@@ -611,38 +628,50 @@ static void maybe_tx_wakeup(unsigned long param)
break;
}
}
rcu_read_unlock();
if (wake)
netif_wake_queue(dev);
}
netif_tx_unlock(dev);
}
static void vnet_event(void *arg, int event)
static inline bool port_is_up(struct vnet_port *vnet)
{
struct vio_driver_state *vio = &vnet->vio;
return !!(vio->hs_state & VIO_HS_COMPLETE);
}
static int vnet_event_napi(struct vnet_port *port, int budget)
{
struct vnet_port *port = arg;
struct vio_driver_state *vio = &port->vio;
unsigned long flags;
int tx_wakeup, err;
int npkts = 0;
int event = (port->rx_event & LDC_EVENT_RESET);
spin_lock_irqsave(&vio->lock, flags);
ldc_ctrl:
if (unlikely(event == LDC_EVENT_RESET ||
event == LDC_EVENT_UP)) {
vio_link_state_change(vio, event);
spin_unlock_irqrestore(&vio->lock, flags);
if (event == LDC_EVENT_RESET) {
port->rmtu = 0;
vio_port_up(vio);
}
return;
port->rx_event = 0;
return 0;
}
/* We may have multiple LDC events in rx_event. Unroll send_events() */
event = (port->rx_event & LDC_EVENT_UP);
port->rx_event &= ~(LDC_EVENT_RESET|LDC_EVENT_UP);
if (event == LDC_EVENT_UP)
goto ldc_ctrl;
event = port->rx_event;
if (!(event & LDC_EVENT_DATA_READY))
return 0;
if (unlikely(event != LDC_EVENT_DATA_READY)) {
pr_warn("Unexpected LDC event %d\n", event);
spin_unlock_irqrestore(&vio->lock, flags);
return;
}
/* we dont expect any other bits than RESET, UP, DATA_READY */
BUG_ON(event != LDC_EVENT_DATA_READY);
tx_wakeup = err = 0;
while (1) {
......@@ -651,6 +680,21 @@ static void vnet_event(void *arg, int event)
u64 raw[8];
} msgbuf;
if (port->napi_resume) {
struct vio_dring_data *pkt =
(struct vio_dring_data *)&msgbuf;
struct vio_dring_state *dr =
&port->vio.drings[VIO_DRIVER_RX_RING];
pkt->tag.type = VIO_TYPE_DATA;
pkt->tag.stype = VIO_SUBTYPE_INFO;
pkt->tag.stype_env = VIO_DRING_DATA;
pkt->seq = dr->rcv_nxt;
pkt->start_idx = next_idx(port->napi_stop_idx, dr);
pkt->end_idx = -1;
goto napi_resume;
}
ldc_read:
err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
if (unlikely(err < 0)) {
if (err == -ECONNRESET)
......@@ -667,10 +711,22 @@ static void vnet_event(void *arg, int event)
err = vio_validate_sid(vio, &msgbuf.tag);
if (err < 0)
break;
napi_resume:
if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
err = vnet_rx(port, &msgbuf);
if (!port_is_up(port)) {
/* failures like handshake_failure()
* may have cleaned up dring, but
* NAPI polling may bring us here.
*/
err = -ECONNRESET;
break;
}
err = vnet_rx(port, &msgbuf, &npkts, budget);
if (npkts >= budget)
break;
if (npkts == 0 && err != -ECONNRESET)
goto ldc_read;
} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
err = vnet_ack(port, &msgbuf);
if (err > 0)
......@@ -691,15 +747,33 @@ static void vnet_event(void *arg, int event)
if (err == -ECONNRESET)
break;
}
spin_unlock(&vio->lock);
/* Kick off a tasklet to wake the queue. We cannot call
* maybe_tx_wakeup directly here because we could deadlock on
* netif_tx_lock() with dev_watchdog()
*/
if (unlikely(tx_wakeup && err != -ECONNRESET))
tasklet_schedule(&port->vp->vnet_tx_wakeup);
maybe_tx_wakeup(port->vp);
return npkts;
}
static int vnet_poll(struct napi_struct *napi, int budget)
{
struct vnet_port *port = container_of(napi, struct vnet_port, napi);
struct vio_driver_state *vio = &port->vio;
int processed = vnet_event_napi(port, budget);
if (processed < budget) {
napi_complete(napi);
vio_set_intr(vio->vdev->rx_ino, HV_INTR_ENABLED);
}
return processed;
}
static void vnet_event(void *arg, int event)
{
struct vnet_port *port = arg;
struct vio_driver_state *vio = &port->vio;
port->rx_event |= event;
vio_set_intr(vio->vdev->rx_ino, HV_INTR_DISABLED);
napi_schedule(&port->napi);
local_irq_restore(flags);
}
static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
......@@ -746,26 +820,19 @@ static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
return err;
}
static inline bool port_is_up(struct vnet_port *vnet)
{
struct vio_driver_state *vio = &vnet->vio;
return !!(vio->hs_state & VIO_HS_COMPLETE);
}
struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
{
unsigned int hash = vnet_hashfn(skb->data);
struct hlist_head *hp = &vp->port_hash[hash];
struct vnet_port *port;
hlist_for_each_entry(port, hp, hash) {
hlist_for_each_entry_rcu(port, hp, hash) {
if (!port_is_up(port))
continue;
if (ether_addr_equal(port->raddr, skb->data))
return port;
}
list_for_each_entry(port, &vp->port_list, list) {
list_for_each_entry_rcu(port, &vp->port_list, list) {
if (!port->switch_port)
continue;
if (!port_is_up(port))
......@@ -775,18 +842,6 @@ struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
return NULL;
}
struct vnet_port *tx_port_find(struct vnet *vp, struct sk_buff *skb)
{
struct vnet_port *ret;
unsigned long flags;
spin_lock_irqsave(&vp->lock, flags);
ret = __tx_port_find(vp, skb);
spin_unlock_irqrestore(&vp->lock, flags);
return ret;
}
static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
unsigned *pending)
{
......@@ -847,11 +902,10 @@ static void vnet_clean_timer_expire(unsigned long port0)
struct vnet_port *port = (struct vnet_port *)port0;
struct sk_buff *freeskbs;
unsigned pending;
unsigned long flags;
spin_lock_irqsave(&port->vio.lock, flags);
netif_tx_lock(port->vp->dev);
freeskbs = vnet_clean_tx_ring(port, &pending);
spin_unlock_irqrestore(&port->vio.lock, flags);
netif_tx_unlock(port->vp->dev);
vnet_free_skbs(freeskbs);
......@@ -901,10 +955,9 @@ static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, void **pstart,
static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct vnet *vp = netdev_priv(dev);
struct vnet_port *port = tx_port_find(vp, skb);
struct vnet_port *port = NULL;
struct vio_dring_state *dr;
struct vio_net_desc *d;
unsigned long flags;
unsigned int len;
struct sk_buff *freeskbs = NULL;
int i, err, txi;
......@@ -912,14 +965,15 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
int nlen = 0;
unsigned pending = 0;
if (unlikely(!port))
goto out_dropped;
skb = vnet_skb_shape(skb, &start, &nlen);
if (unlikely(!skb))
goto out_dropped;
rcu_read_lock();
port = __tx_port_find(vp, skb);
if (unlikely(!port))
goto out_dropped;
if (skb->len > port->rmtu) {
unsigned long localmtu = port->rmtu - ETH_HLEN;
......@@ -937,6 +991,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
fl4.saddr = ip_hdr(skb)->saddr;
rt = ip_route_output_key(dev_net(dev), &fl4);
rcu_read_unlock();
if (!IS_ERR(rt)) {
skb_dst_set(skb, &rt->dst);
icmp_send(skb, ICMP_DEST_UNREACH,
......@@ -951,8 +1006,6 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
goto out_dropped;
}
spin_lock_irqsave(&port->vio.lock, flags);
dr = &port->vio.drings[VIO_DRIVER_TX_RING];
if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
if (!netif_queue_stopped(dev)) {
......@@ -962,7 +1015,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
dev->stats.tx_errors++;
}
spin_unlock_irqrestore(&port->vio.lock, flags);
rcu_read_unlock();
return NETDEV_TX_BUSY;
}
......@@ -986,7 +1039,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
(LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
if (err < 0) {
netdev_info(dev, "tx buffer map error %d\n", err);
goto out_dropped_unlock;
goto out_dropped;
}
port->tx_bufs[txi].ncookies = err;
......@@ -1039,7 +1092,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
netdev_info(dev, "TX trigger error %d\n", err);
d->hdr.state = VIO_DESC_FREE;
dev->stats.tx_carrier_errors++;
goto out_dropped_unlock;
goto out_dropped;
}
ldc_start_done:
......@@ -1055,26 +1108,24 @@ ldc_start_done:
netif_wake_queue(dev);
}
spin_unlock_irqrestore(&port->vio.lock, flags);
(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
rcu_read_unlock();
vnet_free_skbs(freeskbs);
(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
return NETDEV_TX_OK;
out_dropped_unlock:
spin_unlock_irqrestore(&port->vio.lock, flags);
out_dropped:
if (skb)
dev_kfree_skb(skb);
vnet_free_skbs(freeskbs);
if (pending)
(void)mod_timer(&port->clean_timer,
jiffies + VNET_CLEAN_TIMEOUT);
else if (port)
del_timer(&port->clean_timer);
if (port)
rcu_read_unlock();
if (skb)
dev_kfree_skb(skb);
vnet_free_skbs(freeskbs);
dev->stats.tx_dropped++;
return NETDEV_TX_OK;
}
......@@ -1204,18 +1255,17 @@ static void vnet_set_rx_mode(struct net_device *dev)
{
struct vnet *vp = netdev_priv(dev);
struct vnet_port *port;
unsigned long flags;
spin_lock_irqsave(&vp->lock, flags);
if (!list_empty(&vp->port_list)) {
port = list_entry(vp->port_list.next, struct vnet_port, list);
rcu_read_lock();
list_for_each_entry_rcu(port, &vp->port_list, list) {
if (port->switch_port) {
__update_mc_list(vp, dev);
__send_mc_list(vp, port);
break;
}
}
spin_unlock_irqrestore(&vp->lock, flags);
rcu_read_unlock();
}
static int vnet_change_mtu(struct net_device *dev, int new_mtu)
......@@ -1342,6 +1392,21 @@ err_out:
return err;
}
#ifdef CONFIG_NET_POLL_CONTROLLER
static void vnet_poll_controller(struct net_device *dev)
{
struct vnet *vp = netdev_priv(dev);
struct vnet_port *port;
unsigned long flags;
spin_lock_irqsave(&vp->lock, flags);
if (!list_empty(&vp->port_list)) {
port = list_entry(vp->port_list.next, struct vnet_port, list);
napi_schedule(&port->napi);
}
spin_unlock_irqrestore(&vp->lock, flags);
}
#endif
static LIST_HEAD(vnet_list);
static DEFINE_MUTEX(vnet_list_mutex);
......@@ -1354,6 +1419,9 @@ static const struct net_device_ops vnet_ops = {
.ndo_tx_timeout = vnet_tx_timeout,
.ndo_change_mtu = vnet_change_mtu,
.ndo_start_xmit = vnet_start_xmit,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = vnet_poll_controller,
#endif
};
static struct vnet *vnet_new(const u64 *local_mac)
......@@ -1374,7 +1442,6 @@ static struct vnet *vnet_new(const u64 *local_mac)
vp = netdev_priv(dev);
spin_lock_init(&vp->lock);
tasklet_init(&vp->vnet_tx_wakeup, maybe_tx_wakeup, (unsigned long)vp);
vp->dev = dev;
INIT_LIST_HEAD(&vp->port_list);
......@@ -1434,7 +1501,6 @@ static void vnet_cleanup(void)
vp = list_first_entry(&vnet_list, struct vnet, list);
list_del(&vp->list);
dev = vp->dev;
tasklet_kill(&vp->vnet_tx_wakeup);
/* vio_unregister_driver() should have cleaned up port_list */
BUG_ON(!list_empty(&vp->port_list));
unregister_netdev(dev);
......@@ -1536,6 +1602,8 @@ static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
if (err)
goto err_out_free_port;
netif_napi_add(port->vp->dev, &port->napi, vnet_poll, NAPI_POLL_WEIGHT);
err = vnet_port_alloc_tx_bufs(port);
if (err)
goto err_out_free_ldc;
......@@ -1550,10 +1618,11 @@ static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
spin_lock_irqsave(&vp->lock, flags);
if (switch_port)
list_add(&port->list, &vp->port_list);
list_add_rcu(&port->list, &vp->port_list);
else
list_add_tail(&port->list, &vp->port_list);
hlist_add_head(&port->hash, &vp->port_hash[vnet_hashfn(port->raddr)]);
list_add_tail_rcu(&port->list, &vp->port_list);
hlist_add_head_rcu(&port->hash,
&vp->port_hash[vnet_hashfn(port->raddr)]);
spin_unlock_irqrestore(&vp->lock, flags);
dev_set_drvdata(&vdev->dev, port);
......@@ -1564,6 +1633,7 @@ static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
setup_timer(&port->clean_timer, vnet_clean_timer_expire,
(unsigned long)port);
napi_enable(&port->napi);
vio_port_up(&port->vio);
mdesc_release(hp);
......@@ -1571,6 +1641,7 @@ static int vnet_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
return 0;
err_out_free_ldc:
netif_napi_del(&port->napi);
vio_ldc_free(&port->vio);
err_out_free_port:
......@@ -1586,17 +1657,17 @@ static int vnet_port_remove(struct vio_dev *vdev)
struct vnet_port *port = dev_get_drvdata(&vdev->dev);
if (port) {
struct vnet *vp = port->vp;
unsigned long flags;
del_timer_sync(&port->vio.timer);
del_timer_sync(&port->clean_timer);
spin_lock_irqsave(&vp->lock, flags);
list_del(&port->list);
hlist_del(&port->hash);
spin_unlock_irqrestore(&vp->lock, flags);
napi_disable(&port->napi);
list_del_rcu(&port->list);
hlist_del_rcu(&port->hash);
synchronize_rcu();
del_timer_sync(&port->clean_timer);
netif_napi_del(&port->napi);
vnet_port_free_tx_bufs(port);
vio_ldc_free(&port->vio);
......
......@@ -56,6 +56,11 @@ struct vnet_port {
struct timer_list clean_timer;
u64 rmtu;
struct napi_struct napi;
u32 napi_stop_idx;
bool napi_resume;
int rx_event;
};
static inline struct vnet_port *to_vnet_port(struct vio_driver_state *vio)
......@@ -97,7 +102,6 @@ struct vnet {
struct list_head list;
u64 local_mac;
struct tasklet_struct vnet_tx_wakeup;
};
#endif /* _SUNVNET_H */
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