[NET PATCH 6/9] venet: add eventq protocol

Gregory Haskins
2009-10-14T16:09:59Z

This adds an event-channel for passing host->guest messages to the
guest driver. We will use this later in the series for linkstate and
asynchronous transmit-complete events.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
---

drivers/net/vbus-enet.c | 203 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/venet.h | 28 ++++++
2 files changed, 229 insertions(+), 2 deletions(-)

diff --git a/drivers/net/vbus-enet.c b/drivers/net/vbus-enet.c
index fe9eeca..5fccfd1 100644
--- a/drivers/net/vbus-enet.c
+++ b/drivers/net/vbus-enet.c
@@ -66,6 +66,14 @@ struct vbus_enet_priv {
bool enabled;
char *pool;
} pmtd; /* pre-mapped transmit descriptors */
+ struct {
+ bool enabled;
+ bool linkstate;
+ unsigned long evsize;
+ struct vbus_enet_queue veq;
+ struct tasklet_struct task;
+ char *pool;
+ } evq;
};

static void vbus_enet_tx_reap(struct vbus_enet_priv *priv, int force);
@@ -331,6 +339,16 @@ tx_teardown(struct vbus_enet_priv *priv)
}
}

+static void
+evq_teardown(struct vbus_enet_priv *priv)
+{
+ if (!priv->evq.enabled)
+ return;
+
+ ioq_put(priv->evq.veq.queue);
+ kfree(priv->evq.pool);
+}
+
/*
* Open and close
*/
@@ -741,8 +759,91 @@ tx_isr(struct ioq_notifier *notifier)
tasklet_schedule(&priv->txtask);
}

+static void
+evq_linkstate_event(struct vbus_enet_priv *priv,
+ struct venet_event_header *header)
+{
+ struct venet_event_linkstate *event =
+ (struct venet_event_linkstate *)header;
+
+ switch (event->state) {
+ case 0:
+ netif_carrier_off(priv->dev);
+ break;
+ case 1:
+ netif_carrier_on(priv->dev);
+ break;
+ default:
+ break;
+ }
+}
+
+static void
+deferred_evq_isr(unsigned long data)
+{
+ struct vbus_enet_priv *priv = (struct vbus_enet_priv *)data;
+ int nevents = 0;
+ struct ioq_iterator iter;
+ int ret;
+
+ PDEBUG(priv->dev, "evq: polling...\n");
+
+ /* We want to iterate on the head of the in-use index */
+ ret = ioq_iter_init(priv->evq.veq.queue, &iter, ioq_idxtype_inuse,
+ IOQ_ITER_AUTOUPDATE);
+ BUG_ON(ret < 0);
+
+ ret = ioq_iter_seek(&iter, ioq_seek_head, 0, 0);
+ BUG_ON(ret < 0);
+
+ /*
+ * The EOM is indicated by finding a packet that is still owned by
+ * the south side
+ */
+ while (!iter.desc->sown) {
+ struct venet_event_header *header;
+
+ header = (struct venet_event_header *)iter.desc->cookie;
+
+ switch (header->id) {
+ case VENET_EVENT_LINKSTATE:
+ evq_linkstate_event(priv, header);
+ break;
+ default:
+ panic("venet: unexpected event id:%d of size %d\n",
+ header->id, header->size);
+ break;
+ }
+
+ memset((void *)iter.desc->cookie, 0, priv->evq.evsize);
+
+ /* Advance the in-use tail */
+ ret = ioq_iter_pop(&iter, 0);
+ BUG_ON(ret < 0);
+
+ nevents++;
+ }
+
+ PDEBUG(priv->dev, "%d events received\n", nevents);
+
+ ioq_notify_enable(priv->evq.veq.queue, 0);
+}
+
+static void
+evq_isr(struct ioq_notifier *notifier)
+{
+ struct vbus_enet_priv *priv;
+
+ priv = container_of(notifier, struct vbus_enet_priv, evq.veq.notifier);
+
+ PDEBUG(priv->dev, "evq_isr\n");
+
+ ioq_notify_disable(priv->evq.veq.queue, 0);
+ tasklet_schedule(&priv->evq.task);
+}
+
static int
-vbus_enet_negcap(struct vbus_enet_priv *priv)
+vbus_enet_sg_negcap(struct vbus_enet_priv *priv)
{
struct net_device *dev = priv->dev;
struct venet_capabilities caps;
@@ -782,6 +883,103 @@ vbus_enet_negcap(struct vbus_enet_priv *priv)
return 0;
}

+static int
+vbus_enet_evq_negcap(struct vbus_enet_priv *priv, unsigned long count)
+{
+ struct venet_capabilities caps;
+ int ret;
+
+ memset(&caps, 0, sizeof(caps));
+
+ caps.gid = VENET_CAP_GROUP_EVENTQ;
+ caps.bits |= VENET_CAP_EVQ_LINKSTATE;
+
+ ret = devcall(priv, VENET_FUNC_NEGCAP, &caps, sizeof(caps));
+ if (ret < 0)
+ return ret;
+
+ if (caps.bits) {
+ struct vbus_device_proxy *dev = priv->vdev;
+ struct venet_eventq_query query;
+ size_t poollen;
+ struct ioq_iterator iter;
+ char *pool;
+ int i;
+
+ priv->evq.enabled = true;
+
+ if (caps.bits & VENET_CAP_EVQ_LINKSTATE) {
+ /*
+ * We will assume there is no carrier until we get
+ * an event telling us otherwise
+ */
+ netif_carrier_off(priv->dev);
+ priv->evq.linkstate = true;
+ }
+
+ memset(&query, 0, sizeof(query));
+
+ ret = devcall(priv, VENET_FUNC_EVQQUERY, &query, sizeof(query));
+ if (ret < 0)
+ return ret;
+
+ priv->evq.evsize = query.evsize;
+ poollen = query.evsize * count;
+
+ pool = kzalloc(poollen, GFP_KERNEL | GFP_DMA);
+ if (!pool)
+ return -ENOMEM;
+
+ priv->evq.pool = pool;
+
+ ret = dev->ops->shm(dev, query.dpid, 0,
+ pool, poollen, 0, NULL, 0);
+ if (ret < 0)
+ return ret;
+
+ queue_init(priv, &priv->evq.veq, query.qid, count, evq_isr);
+
+ ret = ioq_iter_init(priv->evq.veq.queue,
+ &iter, ioq_idxtype_valid, 0);
+ BUG_ON(ret < 0);
+
+ ret = ioq_iter_seek(&iter, ioq_seek_set, 0, 0);
+ BUG_ON(ret < 0);
+
+ /* Now populate each descriptor with an empty event */
+ for (i = 0; i < count; i++) {
+ size_t offset = (i * query.evsize);
+ void *addr = &priv->evq.pool[offset];
+
+ iter.desc->ptr = (u64)offset;
+ iter.desc->cookie = (u64)addr;
+ iter.desc->len = query.evsize;
+
+ ret = ioq_iter_push(&iter, 0);
+ BUG_ON(ret < 0);
+ }
+
+ /* Finally, enable interrupts */
+ tasklet_init(&priv->evq.task, deferred_evq_isr,
+ (unsigned long)priv);
+ ioq_notify_enable(priv->evq.veq.queue, 0);
+ }
+
+ return 0;
+}
+
+static int
+vbus_enet_negcap(struct vbus_enet_priv *priv)
+{
+ int ret;
+
+ ret = vbus_enet_sg_negcap(priv);
+ if (ret < 0)
+ return ret;
+
+ return vbus_enet_evq_negcap(priv, tx_ringlen);
+}
+
static int vbus_enet_set_tx_csum(struct net_device *dev, u32 data)
{
struct vbus_enet_priv *priv = netdev_priv(dev);
@@ -905,6 +1103,9 @@ vbus_enet_remove(struct vbus_device_proxy *vdev)
tx_teardown(priv);
ioq_put(priv->txq.queue);

+ if (priv->evq.enabled)
+ evq_teardown(priv);
+
dev->ops->close(dev, 0);

free_netdev(priv->dev);
diff --git a/include/linux/venet.h b/include/linux/venet.h
index 53b6958..16b0156 100644
--- a/include/linux/venet.h
+++ b/include/linux/venet.h
@@ -37,7 +37,8 @@ struct venet_capabilities {
__u32 bits;
};

-#define VENET_CAP_GROUP_SG 0
+#define VENET_CAP_GROUP_SG 0
+#define VENET_CAP_GROUP_EVENTQ 1

/* CAPABILITIES-GROUP SG */
#define VENET_CAP_SG (1 << 0)
@@ -47,6 +48,9 @@ struct venet_capabilities {
#define VENET_CAP_UFO (1 << 4)
#define VENET_CAP_PMTD (1 << 5) /* pre-mapped tx desc */

+/* CAPABILITIES-GROUP EVENTQ */
+#define VENET_CAP_EVQ_LINKSTATE (1 << 0)
+
struct venet_iov {
__u32 len;
__u64 ptr;
@@ -76,6 +80,27 @@ struct venet_sg {
struct venet_iov iov[1];
};

+struct venet_eventq_query {
+ __u32 flags;
+ __u32 evsize; /* size of each event */
+ __u32 dpid; /* descriptor pool-id */
+ __u32 qid;
+ __u8 pad[16];
+};
+
+#define VENET_EVENT_LINKSTATE 0
+
+struct venet_event_header {
+ __u32 flags;
+ __u32 size;
+ __u32 id;
+};
+
+struct venet_event_linkstate {
+ struct venet_event_header header;
+ __u8 state; /* 0 = down, 1 = up */
+};
+
#define VSG_DESC_SIZE(count) (sizeof(struct venet_sg) + \
sizeof(struct venet_iov) * ((count) - 1))

@@ -85,5 +110,6 @@ struct venet_sg {
#define VENET_FUNC_NEGCAP 3 /* negotiate capabilities */
#define VENET_FUNC_FLUSHRX 4
#define VENET_FUNC_PMTDQUERY 5
+#define VENET_FUNC_EVQQUERY 6

#endif /* _LINUX_VENET_H */