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path: root/drivers/xen/pvcalls-back.c
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Diffstat (limited to 'drivers/xen/pvcalls-back.c')
-rw-r--r--drivers/xen/pvcalls-back.c79
1 files changed, 48 insertions, 31 deletions
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index 58be15c27b6d..b13d03aba791 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -75,6 +75,7 @@ struct sock_mapping {
atomic_t write;
atomic_t io;
atomic_t release;
+ atomic_t eoi;
void (*saved_data_ready)(struct sock *sk);
struct pvcalls_ioworker ioworker;
};
@@ -96,7 +97,7 @@ static int pvcalls_back_release_active(struct xenbus_device *dev,
struct pvcalls_fedata *fedata,
struct sock_mapping *map);
-static void pvcalls_conn_back_read(void *opaque)
+static bool pvcalls_conn_back_read(void *opaque)
{
struct sock_mapping *map = (struct sock_mapping *)opaque;
struct msghdr msg;
@@ -116,17 +117,17 @@ static void pvcalls_conn_back_read(void *opaque)
virt_mb();
if (error)
- return;
+ return false;
size = pvcalls_queued(prod, cons, array_size);
if (size >= array_size)
- return;
+ return false;
spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) {
atomic_set(&map->read, 0);
spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock,
flags);
- return;
+ return true;
}
spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
wanted = array_size - size;
@@ -154,7 +155,7 @@ static void pvcalls_conn_back_read(void *opaque)
ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT);
WARN_ON(ret > wanted);
if (ret == -EAGAIN) /* shouldn't happen */
- return;
+ return true;
if (!ret)
ret = -ENOTCONN;
spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
@@ -173,10 +174,10 @@ static void pvcalls_conn_back_read(void *opaque)
virt_wmb();
notify_remote_via_irq(map->irq);
- return;
+ return true;
}
-static void pvcalls_conn_back_write(struct sock_mapping *map)
+static bool pvcalls_conn_back_write(struct sock_mapping *map)
{
struct pvcalls_data_intf *intf = map->ring;
struct pvcalls_data *data = &map->data;
@@ -193,7 +194,7 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
array_size = XEN_FLEX_RING_SIZE(map->ring_order);
size = pvcalls_queued(prod, cons, array_size);
if (size == 0)
- return;
+ return false;
memset(&msg, 0, sizeof(msg));
msg.msg_flags |= MSG_DONTWAIT;
@@ -215,12 +216,11 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
atomic_set(&map->write, 0);
ret = inet_sendmsg(map->sock, &msg, size);
- if (ret == -EAGAIN || (ret >= 0 && ret < size)) {
+ if (ret == -EAGAIN) {
atomic_inc(&map->write);
atomic_inc(&map->io);
+ return true;
}
- if (ret == -EAGAIN)
- return;
/* write the data, then update the indexes */
virt_wmb();
@@ -233,9 +233,13 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
}
/* update the indexes, then notify the other end */
virt_wmb();
- if (prod != cons + ret)
+ if (prod != cons + ret) {
atomic_inc(&map->write);
+ atomic_inc(&map->io);
+ }
notify_remote_via_irq(map->irq);
+
+ return true;
}
static void pvcalls_back_ioworker(struct work_struct *work)
@@ -244,6 +248,7 @@ static void pvcalls_back_ioworker(struct work_struct *work)
struct pvcalls_ioworker, register_work);
struct sock_mapping *map = container_of(ioworker, struct sock_mapping,
ioworker);
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
while (atomic_read(&map->io) > 0) {
if (atomic_read(&map->release) > 0) {
@@ -251,10 +256,18 @@ static void pvcalls_back_ioworker(struct work_struct *work)
return;
}
- if (atomic_read(&map->read) > 0)
- pvcalls_conn_back_read(map);
- if (atomic_read(&map->write) > 0)
- pvcalls_conn_back_write(map);
+ if (atomic_read(&map->read) > 0 &&
+ pvcalls_conn_back_read(map))
+ eoi_flags = 0;
+ if (atomic_read(&map->write) > 0 &&
+ pvcalls_conn_back_write(map))
+ eoi_flags = 0;
+
+ if (atomic_read(&map->eoi) > 0 && !atomic_read(&map->write)) {
+ atomic_set(&map->eoi, 0);
+ xen_irq_lateeoi(map->irq, eoi_flags);
+ eoi_flags = XEN_EOI_FLAG_SPURIOUS;
+ }
atomic_dec(&map->io);
}
@@ -351,12 +364,9 @@ static struct sock_mapping *pvcalls_new_active_socket(
goto out;
map->bytes = page;
- ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id,
- evtchn,
- pvcalls_back_conn_event,
- 0,
- "pvcalls-backend",
- map);
+ ret = bind_interdomain_evtchn_to_irqhandler_lateeoi(
+ fedata->dev->otherend_id, evtchn,
+ pvcalls_back_conn_event, 0, "pvcalls-backend", map);
if (ret < 0)
goto out;
map->irq = ret;
@@ -890,15 +900,18 @@ static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
{
struct xenbus_device *dev = dev_id;
struct pvcalls_fedata *fedata = NULL;
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
- if (dev == NULL)
- return IRQ_HANDLED;
+ if (dev) {
+ fedata = dev_get_drvdata(&dev->dev);
+ if (fedata) {
+ pvcalls_back_work(fedata);
+ eoi_flags = 0;
+ }
+ }
- fedata = dev_get_drvdata(&dev->dev);
- if (fedata == NULL)
- return IRQ_HANDLED;
+ xen_irq_lateeoi(irq, eoi_flags);
- pvcalls_back_work(fedata);
return IRQ_HANDLED;
}
@@ -908,12 +921,15 @@ static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
struct pvcalls_ioworker *iow;
if (map == NULL || map->sock == NULL || map->sock->sk == NULL ||
- map->sock->sk->sk_user_data != map)
+ map->sock->sk->sk_user_data != map) {
+ xen_irq_lateeoi(irq, 0);
return IRQ_HANDLED;
+ }
iow = &map->ioworker;
atomic_inc(&map->write);
+ atomic_inc(&map->eoi);
atomic_inc(&map->io);
queue_work(iow->wq, &iow->register_work);
@@ -948,7 +964,7 @@ static int backend_connect(struct xenbus_device *dev)
goto error;
}
- err = bind_interdomain_evtchn_to_irq(dev->otherend_id, evtchn);
+ err = bind_interdomain_evtchn_to_irq_lateeoi(dev->otherend_id, evtchn);
if (err < 0)
goto error;
fedata->irq = err;
@@ -1104,7 +1120,8 @@ static void set_backend_state(struct xenbus_device *dev,
case XenbusStateInitialised:
switch (state) {
case XenbusStateConnected:
- backend_connect(dev);
+ if (backend_connect(dev))
+ return;
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateClosing: