3 files changed, 23 insertions, 15 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 602ca86a6488..740edec161bb 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -471,18 +471,26 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 }
 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 
+static void reset_channel_cb(void *arg)
+{
+        struct vmbus_channel *channel = arg;
+
+        channel->onchannel_callback = NULL;
+}
+
 static void vmbus_close_internal(struct vmbus_channel *channel)
 {
         struct vmbus_channel_close_channel *msg;
         int ret;
-        unsigned long flags;
 
         channel->state = CHANNEL_OPEN_STATE;
         channel->sc_creation_callback = NULL;
         /* Stop callback and cancel the timer asap */
-        spin_lock_irqsave(&channel->inbound_lock, flags);
-        channel->onchannel_callback = NULL;
-        spin_unlock_irqrestore(&channel->inbound_lock, flags);
+        if (channel->target_cpu != smp_processor_id())
+                smp_call_function_single(channel->target_cpu, reset_channel_cb,
+                                         channel, true);
+        else
+                reset_channel_cb(channel);
 
         /* Send a closing message */
 
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index fa920469bf10..6f7fdd9a7e77 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -365,7 +365,7 @@ static u32  next_vp;
  * performance critical channels (IDE, SCSI and Network) will be uniformly
  * distributed across all available CPUs.
  */
-static u32 get_vp_index(uuid_le *type_guid)
+static void init_vp_index(struct vmbus_channel *channel, uuid_le *type_guid)
 {
         u32 cur_cpu;
         int i;
@@ -387,10 +387,13 @@ static u32 get_vp_index(uuid_le *type_guid)
                  * Also if the channel is not a performance critical
                  * channel, bind it to cpu 0.
                  */
-                return 0;
+                channel->target_cpu = 0;
+                channel->target_vp = 0;
+                return;
         }
         cur_cpu = (++next_vp % max_cpus);
-        return hv_context.vp_index[cur_cpu];
+        channel->target_cpu = cur_cpu;
+        channel->target_vp = hv_context.vp_index[cur_cpu];
 }
 
 /*
@@ -438,7 +441,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
                                 offer->connection_id;
         }
 
-        newchannel->target_vp = get_vp_index(&offer->offer.if_type);
+        init_vp_index(newchannel, &offer->offer.if_type);
 
         memcpy(&newchannel->offermsg, offer,
                sizeof(struct vmbus_channel_offer_channel));
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 2e7801af466e..df2363ea017f 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -277,7 +277,6 @@ struct vmbus_channel *relid2channel(u32 relid)
 static void process_chn_event(u32 relid)
 {
         struct vmbus_channel *channel;
-        unsigned long flags;
         void *arg;
         bool read_state;
         u32 bytes_to_read;
@@ -296,13 +295,12 @@ static void process_chn_event(u32 relid)
         /*
          * A channel once created is persistent even when there
          * is no driver handling the device. An unloading driver
-         * sets the onchannel_callback to NULL under the
-         * protection of the channel inbound_lock. Thus, checking
-         * and invoking the driver specific callback takes care of
-         * orderly unloading of the driver.
+         * sets the onchannel_callback to NULL on the same CPU
+         * as where this interrupt is handled (in an interrupt context).
+         * Thus, checking and invoking the driver specific callback takes
+         * care of orderly unloading of the driver.
          */
 
-        spin_lock_irqsave(&channel->inbound_lock, flags);
         if (channel->onchannel_callback != NULL) {
                 arg = channel->channel_callback_context;
                 read_state = channel->batched_reading;
@@ -327,7 +325,6 @@ static void process_chn_event(u32 relid)
                 pr_err("no channel callback for relid - %u\n", relid);
         }
 
-        spin_unlock_irqrestore(&channel->inbound_lock, flags);
 }
 
 /*