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path: root/drivers/hv/channel_mgmt.c
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Diffstat (limited to 'drivers/hv/channel_mgmt.c')
-rw-r--r--drivers/hv/channel_mgmt.c119
1 files changed, 115 insertions, 4 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 21ef68934a20..0df75908200e 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -115,6 +115,9 @@ static struct vmbus_channel *alloc_channel(void)
return NULL;
spin_lock_init(&channel->inbound_lock);
+ spin_lock_init(&channel->sc_lock);
+
+ INIT_LIST_HEAD(&channel->sc_list);
channel->controlwq = create_workqueue("hv_vmbus_ctl");
if (!channel->controlwq) {
@@ -166,6 +169,7 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
struct vmbus_channel,
work);
unsigned long flags;
+ struct vmbus_channel *primary_channel;
struct vmbus_channel_relid_released msg;
vmbus_device_unregister(channel->device_obj);
@@ -174,9 +178,16 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
- spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
- list_del(&channel->listentry);
- spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+ if (channel->primary_channel == NULL) {
+ spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+ list_del(&channel->listentry);
+ spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+ } else {
+ primary_channel = channel->primary_channel;
+ spin_lock_irqsave(&primary_channel->sc_lock, flags);
+ list_del(&channel->listentry);
+ spin_unlock_irqrestore(&primary_channel->sc_lock, flags);
+ }
free_channel(channel);
}
@@ -228,6 +239,24 @@ static void vmbus_process_offer(struct work_struct *work)
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
if (!fnew) {
+ /*
+ * Check to see if this is a sub-channel.
+ */
+ if (newchannel->offermsg.offer.sub_channel_index != 0) {
+ /*
+ * Process the sub-channel.
+ */
+ newchannel->primary_channel = channel;
+ spin_lock_irqsave(&channel->sc_lock, flags);
+ list_add_tail(&newchannel->sc_list, &channel->sc_list);
+ spin_unlock_irqrestore(&channel->sc_lock, flags);
+ newchannel->state = CHANNEL_OPEN_STATE;
+ if (channel->sc_creation_callback != NULL)
+ channel->sc_creation_callback(newchannel);
+
+ return;
+ }
+
free_channel(newchannel);
return;
}
@@ -685,4 +714,86 @@ cleanup:
return ret;
}
-/* eof */
+/*
+ * Retrieve the (sub) channel on which to send an outgoing request.
+ * When a primary channel has multiple sub-channels, we choose a
+ * channel whose VCPU binding is closest to the VCPU on which
+ * this call is being made.
+ */
+struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
+{
+ struct list_head *cur, *tmp;
+ int cur_cpu = hv_context.vp_index[smp_processor_id()];
+ struct vmbus_channel *cur_channel;
+ struct vmbus_channel *outgoing_channel = primary;
+ int cpu_distance, new_cpu_distance;
+
+ if (list_empty(&primary->sc_list))
+ return outgoing_channel;
+
+ list_for_each_safe(cur, tmp, &primary->sc_list) {
+ cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
+ if (cur_channel->state != CHANNEL_OPENED_STATE)
+ continue;
+
+ if (cur_channel->target_vp == cur_cpu)
+ return cur_channel;
+
+ cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ?
+ (outgoing_channel->target_vp - cur_cpu) :
+ (cur_cpu - outgoing_channel->target_vp));
+
+ new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ?
+ (cur_channel->target_vp - cur_cpu) :
+ (cur_cpu - cur_channel->target_vp));
+
+ if (cpu_distance < new_cpu_distance)
+ continue;
+
+ outgoing_channel = cur_channel;
+ }
+
+ return outgoing_channel;
+}
+EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel);
+
+static void invoke_sc_cb(struct vmbus_channel *primary_channel)
+{
+ struct list_head *cur, *tmp;
+ struct vmbus_channel *cur_channel;
+
+ if (primary_channel->sc_creation_callback == NULL)
+ return;
+
+ list_for_each_safe(cur, tmp, &primary_channel->sc_list) {
+ cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
+
+ primary_channel->sc_creation_callback(cur_channel);
+ }
+}
+
+void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
+ void (*sc_cr_cb)(struct vmbus_channel *new_sc))
+{
+ primary_channel->sc_creation_callback = sc_cr_cb;
+}
+EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback);
+
+bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
+{
+ bool ret;
+
+ ret = !list_empty(&primary->sc_list);
+
+ if (ret) {
+ /*
+ * Invoke the callback on sub-channel creation.
+ * This will present a uniform interface to the
+ * clients.
+ */
+ invoke_sc_cb(primary);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);