Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 29 insertions, 10 deletions

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 2e7801a..e84f452 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -224,8 +224,8 @@ cleanup:
 		vmbus_connection.int_page = NULL;
 	}
 
-	free_pages((unsigned long)vmbus_connection.monitor_pages[0], 1);
-	free_pages((unsigned long)vmbus_connection.monitor_pages[1], 1);
+	free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0);
+	free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0);
 	vmbus_connection.monitor_pages[0] = NULL;
 	vmbus_connection.monitor_pages[1] = NULL;
 
@@ -234,6 +234,28 @@ cleanup:
 	return ret;
 }
 
+/*
+ * Map the given relid to the corresponding channel based on the
+ * per-cpu list of channels that have been affinitized to this CPU.
+ * This will be used in the channel callback path as we can do this
+ * mapping in a lock-free fashion.
+ */
+static struct vmbus_channel *pcpu_relid2channel(u32 relid)
+{
+	struct vmbus_channel *channel;
+	struct vmbus_channel *found_channel  = NULL;
+	int cpu = smp_processor_id();
+	struct list_head *pcpu_head = &hv_context.percpu_list[cpu];
+
+	list_for_each_entry(channel, pcpu_head, percpu_list) {
+		if (channel->offermsg.child_relid == relid) {
+			found_channel = channel;
+			break;
+		}
+	}
+
+	return found_channel;
+}
 
 /*
  * relid2channel - Get the channel object given its
@@ -277,7 +299,6 @@ 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;
@@ -286,7 +307,7 @@ static void process_chn_event(u32 relid)
 	 * Find the channel based on this relid and invokes the
 	 * channel callback to process the event
 	 */
-	channel = relid2channel(relid);
+	channel = pcpu_relid2channel(relid);
 
 	if (!channel) {
 		pr_err("channel not found for relid - %u\n", relid);
@@ -296,13 +317,12 @@ 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 +347,6 @@ static void process_chn_event(u32 relid)
 		pr_err("no channel callback for relid - %u\n", relid);
 	}
 
-	spin_unlock_irqrestore(&channel->inbound_lock, flags);
 }
 
 /*