From: kys@exchange.microsoft.com
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
        devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com,
        vkuznets@redhat.com, jasowang@redhat.com,
        leann.ogasawara@canonical.com
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Subject: [PATCH V2 04/15] Drivers: hv: vmbus: Enhance the rescind callback functionality
Date: Sat,  3 Dec 2016 12:34:31 -0800
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From: K. Y. Srinivasan <kys@microsoft.com>

Enhance the rescind callback functionality by permitting the passing of an opaque
pointer. This functionality will be used by vmbus device drivers to implement
rescind related cleanup more efficiently.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/channel_mgmt.c |   11 +++++++----
 include/linux/hyperv.h    |    7 ++++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f9c5827..d83c1ac 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -825,8 +825,10 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 
 	if (channel->device_obj) {
 		if (channel->chn_rescind_callback) {
-			channel->chn_rescind_callback(channel);
-			goto out;
+			channel->chn_rescind_callback(channel,
+						      channel->rescind_arg);
+			if (is_hvsock_channel(channel))
+				goto out;
 		}
 		/*
 		 * We will have to unregister this device from the
@@ -1215,9 +1217,10 @@ bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
 }
 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);
 
-void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel,
-		void (*chn_rescind_cb)(struct vmbus_channel *))
+void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel, void *arg,
+		void (*chn_rescind_cb)(struct vmbus_channel *, void *))
 {
 	channel->chn_rescind_callback = chn_rescind_cb;
+	channel->rescind_arg = arg;
 }
 EXPORT_SYMBOL_GPL(vmbus_set_chn_rescind_callback);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 35053f9..a9a0ce4 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -800,7 +800,8 @@ struct vmbus_channel {
 	 * Channel rescind callback. Some channels (the hvsock ones), need to
 	 * register a callback which is invoked in vmbus_onoffer_rescind().
 	 */
-	void (*chn_rescind_callback)(struct vmbus_channel *channel);
+	void (*chn_rescind_callback)(struct vmbus_channel *channel, void *arg);
+	void *rescind_arg;
 
 	/*
 	 * The spinlock to protect the structure. It is being used to protect
@@ -957,8 +958,8 @@ static inline void clear_low_latency_mode(struct vmbus_channel *c)
 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
 			void (*sc_cr_cb)(struct vmbus_channel *new_sc));
 
-void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel,
-		void (*chn_rescind_cb)(struct vmbus_channel *));
+void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel, void *arg,
+		void (*chn_rescind_cb)(struct vmbus_channel *, void *));
 
 /*
  * Retrieve the (sub) channel on which to send an outgoing request.
-- 
1.7.4.1