[PATCH 0/3] Drivers: net: hyperv: Cleanup the hyper-V networking code

[PATCH 0/3] Drivers: net: hyperv: Cleanup the hyper-V networking code

[K. Y. Srinivasan]

Get rid of some unnecessary code and some general cleanup.

K. Y. Srinivasan (3):
  Drivers: net: hyperv: Get rid of the rndis_filter_packet structure
  Drivers: net: hyperv: Cleanup the receive path
  Drivers: net: hyperv: Cleanup the netvsc receive callback functio

 drivers/net/hyperv/hyperv_net.h   |    8 +---
 drivers/net/hyperv/netvsc.c       |   62 +++++++++++++-----------------------
 drivers/net/hyperv/netvsc_drv.c   |    2 +-
 drivers/net/hyperv/rndis_filter.c |   41 ++----------------------
 4 files changed, 29 insertions(+), 84 deletions(-)

-- 
1.7.4.1

[PATCH 0/3] Drivers: net: hyperv: Cleanup the hyper-V networking code

[K. Y. Srinivasan]

Get rid of some unnecessary code and some general cleanup.

K. Y. Srinivasan (3):
  Drivers: net: hyperv: Get rid of the rndis_filter_packet structure
  Drivers: net: hyperv: Cleanup the receive path
  Drivers: net: hyperv: Cleanup the netvsc receive callback functio

 drivers/net/hyperv/hyperv_net.h   |    8 +---
 drivers/net/hyperv/netvsc.c       |   62 +++++++++++++-----------------------
 drivers/net/hyperv/netvsc_drv.c   |    2 +-
 drivers/net/hyperv/rndis_filter.c |   41 ++----------------------
 4 files changed, 29 insertions(+), 84 deletions(-)

-- 
1.7.4.1

[PATCH 1/3] Drivers: net: hyperv: Get rid of the rndis_filter_packet structure

[K. Y. Srinivasan]

This structure is redundant; get rid of it make the code little more efficient -
get rid of the unnecessary indirection.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h   |    6 -----
 drivers/net/hyperv/netvsc_drv.c   |    2 +-
 drivers/net/hyperv/rndis_filter.c |   41 ++----------------------------------
 3 files changed, 4 insertions(+), 45 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 7b594ce..7645ba3 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -846,12 +846,6 @@ struct rndis_message {
 };
 
 
-struct rndis_filter_packet {
-	void *completion_ctx;
-	void (*completion)(void *context);
-	struct rndis_message msg;
-};
-
 /* Handy macros */
 
 /* get the size of an RNDIS message. Pass in the message type, */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 18916f7..4950a79 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -155,7 +155,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	/* Allocate a netvsc packet based on # of frags. */
 	packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 			 (num_pages * sizeof(struct hv_page_buffer)) +
-			 sizeof(struct rndis_filter_packet) +
+			 sizeof(struct rndis_message) +
 			 NDIS_VLAN_PPI_SIZE, GFP_ATOMIC);
 	if (!packet) {
 		/* out of memory, drop packet */
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 1084e5d..f0cc8ef 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -58,9 +58,6 @@ struct rndis_request {
 	u8 request_ext[RNDIS_EXT_LEN];
 };
 
-static void rndis_filter_send_completion(void *ctx);
-
-
 static struct rndis_device *get_rndis_device(void)
 {
 	struct rndis_device *device;
@@ -277,7 +274,7 @@ static void rndis_filter_receive_response(struct rndis_device *dev,
 				"rndis response buffer overflow "
 				"detected (size %u max %zu)\n",
 				resp->msg_len,
-				sizeof(struct rndis_filter_packet));
+				sizeof(struct rndis_message));
 
 			if (resp->ndis_msg_type ==
 			    RNDIS_MSG_RESET_C) {
@@ -898,17 +895,14 @@ int rndis_filter_close(struct hv_device *dev)
 int rndis_filter_send(struct hv_device *dev,
 			     struct hv_netvsc_packet *pkt)
 {
-	int ret;
-	struct rndis_filter_packet *filter_pkt;
 	struct rndis_message *rndis_msg;
 	struct rndis_packet *rndis_pkt;
 	u32 rndis_msg_size;
 	bool isvlan = pkt->vlan_tci & VLAN_TAG_PRESENT;
 
 	/* Add the rndis header */
-	filter_pkt = (struct rndis_filter_packet *)pkt->extension;
+	rndis_msg = (struct rndis_message *)pkt->extension;
 
-	rndis_msg = &filter_pkt->msg;
 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
 	if (isvlan)
 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
@@ -961,34 +955,5 @@ int rndis_filter_send(struct hv_device *dev,
 		pkt->page_buf[1].len = rndis_msg_size - pkt->page_buf[0].len;
 	}
 
-	/* Save the packet send completion and context */
-	filter_pkt->completion = pkt->completion.send.send_completion;
-	filter_pkt->completion_ctx =
-				pkt->completion.send.send_completion_ctx;
-
-	/* Use ours */
-	pkt->completion.send.send_completion = rndis_filter_send_completion;
-	pkt->completion.send.send_completion_ctx = filter_pkt;
-
-	ret = netvsc_send(dev, pkt);
-	if (ret != 0) {
-		/*
-		 * Reset the completion to originals to allow retries from
-		 * above
-		 */
-		pkt->completion.send.send_completion =
-				filter_pkt->completion;
-		pkt->completion.send.send_completion_ctx =
-				filter_pkt->completion_ctx;
-	}
-
-	return ret;
-}
-
-static void rndis_filter_send_completion(void *ctx)
-{
-	struct rndis_filter_packet *filter_pkt = ctx;
-
-	/* Pass it back to the original handler */
-	filter_pkt->completion(filter_pkt->completion_ctx);
+	return netvsc_send(dev, pkt);
 }
-- 
1.7.4.1

[PATCH 1/3] Drivers: net: hyperv: Get rid of the rndis_filter_packet structure

[K. Y. Srinivasan]

This structure is redundant; get rid of it make the code little more efficient -
get rid of the unnecessary indirection.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h   |    6 -----
 drivers/net/hyperv/netvsc_drv.c   |    2 +-
 drivers/net/hyperv/rndis_filter.c |   41 ++----------------------------------
 3 files changed, 4 insertions(+), 45 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 7b594ce..7645ba3 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -846,12 +846,6 @@ struct rndis_message {
 };
 
 
-struct rndis_filter_packet {
-	void *completion_ctx;
-	void (*completion)(void *context);
-	struct rndis_message msg;
-};
-
 /* Handy macros */
 
 /* get the size of an RNDIS message. Pass in the message type, */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 18916f7..4950a79 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -155,7 +155,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	/* Allocate a netvsc packet based on # of frags. */
 	packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 			 (num_pages * sizeof(struct hv_page_buffer)) +
-			 sizeof(struct rndis_filter_packet) +
+			 sizeof(struct rndis_message) +
 			 NDIS_VLAN_PPI_SIZE, GFP_ATOMIC);
 	if (!packet) {
 		/* out of memory, drop packet */
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 1084e5d..f0cc8ef 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -58,9 +58,6 @@ struct rndis_request {
 	u8 request_ext[RNDIS_EXT_LEN];
 };
 
-static void rndis_filter_send_completion(void *ctx);
-
-
 static struct rndis_device *get_rndis_device(void)
 {
 	struct rndis_device *device;
@@ -277,7 +274,7 @@ static void rndis_filter_receive_response(struct rndis_device *dev,
 				"rndis response buffer overflow "
 				"detected (size %u max %zu)\n",
 				resp->msg_len,
-				sizeof(struct rndis_filter_packet));
+				sizeof(struct rndis_message));
 
 			if (resp->ndis_msg_type ==
 			    RNDIS_MSG_RESET_C) {
@@ -898,17 +895,14 @@ int rndis_filter_close(struct hv_device *dev)
 int rndis_filter_send(struct hv_device *dev,
 			     struct hv_netvsc_packet *pkt)
 {
-	int ret;
-	struct rndis_filter_packet *filter_pkt;
 	struct rndis_message *rndis_msg;
 	struct rndis_packet *rndis_pkt;
 	u32 rndis_msg_size;
 	bool isvlan = pkt->vlan_tci & VLAN_TAG_PRESENT;
 
 	/* Add the rndis header */
-	filter_pkt = (struct rndis_filter_packet *)pkt->extension;
+	rndis_msg = (struct rndis_message *)pkt->extension;
 
-	rndis_msg = &filter_pkt->msg;
 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
 	if (isvlan)
 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
@@ -961,34 +955,5 @@ int rndis_filter_send(struct hv_device *dev,
 		pkt->page_buf[1].len = rndis_msg_size - pkt->page_buf[0].len;
 	}
 
-	/* Save the packet send completion and context */
-	filter_pkt->completion = pkt->completion.send.send_completion;
-	filter_pkt->completion_ctx =
-				pkt->completion.send.send_completion_ctx;
-
-	/* Use ours */
-	pkt->completion.send.send_completion = rndis_filter_send_completion;
-	pkt->completion.send.send_completion_ctx = filter_pkt;
-
-	ret = netvsc_send(dev, pkt);
-	if (ret != 0) {
-		/*
-		 * Reset the completion to originals to allow retries from
-		 * above
-		 */
-		pkt->completion.send.send_completion =
-				filter_pkt->completion;
-		pkt->completion.send.send_completion_ctx =
-				filter_pkt->completion_ctx;
-	}
-
-	return ret;
-}
-
-static void rndis_filter_send_completion(void *ctx)
-{
-	struct rndis_filter_packet *filter_pkt = ctx;
-
-	/* Pass it back to the original handler */
-	filter_pkt->completion(filter_pkt->completion_ctx);
+	return netvsc_send(dev, pkt);
 }
-- 
1.7.4.1

[PATCH 2/3] Drivers: net: hyperv: Cleanup the receive path

[K. Y. Srinivasan]

Make the receive path a little more efficient by parameterizing the
required state rather than re-establishing that state.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/netvsc.c |   29 +++++++++++++----------------
 1 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 03a2c6e..7fa2bba 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -432,17 +432,14 @@ static inline u32 hv_ringbuf_avail_percent(
 	return avail_write * 100 / ring_info->ring_datasize;
 }
 
-static void netvsc_send_completion(struct hv_device *device,
+static void netvsc_send_completion(struct netvsc_device *net_device,
+				   struct hv_device *device,
 				   struct vmpacket_descriptor *packet)
 {
-	struct netvsc_device *net_device;
 	struct nvsp_message *nvsp_packet;
 	struct hv_netvsc_packet *nvsc_packet;
 	struct net_device *ndev;
 
-	net_device = get_inbound_net_device(device);
-	if (!net_device)
-		return;
 	ndev = net_device->ndev;
 
 	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
@@ -561,13 +558,13 @@ int netvsc_send(struct hv_device *device,
 }
 
 static void netvsc_send_recv_completion(struct hv_device *device,
+					struct netvsc_device *net_device,
 					u64 transaction_id, u32 status)
 {
 	struct nvsp_message recvcompMessage;
 	int retries = 0;
 	int ret;
 	struct net_device *ndev;
-	struct netvsc_device *net_device = hv_get_drvdata(device);
 
 	ndev = net_device->ndev;
 
@@ -653,14 +650,15 @@ static void netvsc_receive_completion(void *context)
 
 	/* Send a receive completion for the xfer page packet */
 	if (fsend_receive_comp)
-		netvsc_send_recv_completion(device, transaction_id, status);
+		netvsc_send_recv_completion(device, net_device, transaction_id,
+					status);
 
 }
 
-static void netvsc_receive(struct hv_device *device,
-			    struct vmpacket_descriptor *packet)
+static void netvsc_receive(struct netvsc_device *net_device,
+			struct hv_device *device,
+			struct vmpacket_descriptor *packet)
 {
-	struct netvsc_device *net_device;
 	struct vmtransfer_page_packet_header *vmxferpage_packet;
 	struct nvsp_message *nvsp_packet;
 	struct hv_netvsc_packet *netvsc_packet = NULL;
@@ -673,9 +671,6 @@ static void netvsc_receive(struct hv_device *device,
 
 	LIST_HEAD(listHead);
 
-	net_device = get_inbound_net_device(device);
-	if (!net_device)
-		return;
 	ndev = net_device->ndev;
 
 	/*
@@ -741,7 +736,7 @@ static void netvsc_receive(struct hv_device *device,
 		spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 				       flags);
 
-		netvsc_send_recv_completion(device,
+		netvsc_send_recv_completion(device, net_device,
 					    vmxferpage_packet->d.trans_id,
 					    NVSP_STAT_FAIL);
 
@@ -825,11 +820,13 @@ static void netvsc_channel_cb(void *context)
 				desc = (struct vmpacket_descriptor *)buffer;
 				switch (desc->type) {
 				case VM_PKT_COMP:
-					netvsc_send_completion(device, desc);
+					netvsc_send_completion(net_device,
+								device, desc);
 					break;
 
 				case VM_PKT_DATA_USING_XFER_PAGES:
-					netvsc_receive(device, desc);
+					netvsc_receive(net_device,
+							device, desc);
 					break;
 
 				default:
-- 
1.7.4.1

[PATCH 2/3] Drivers: net: hyperv: Cleanup the receive path

[K. Y. Srinivasan]

Make the receive path a little more efficient by parameterizing the
required state rather than re-establishing that state.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/netvsc.c |   29 +++++++++++++----------------
 1 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 03a2c6e..7fa2bba 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -432,17 +432,14 @@ static inline u32 hv_ringbuf_avail_percent(
 	return avail_write * 100 / ring_info->ring_datasize;
 }
 
-static void netvsc_send_completion(struct hv_device *device,
+static void netvsc_send_completion(struct netvsc_device *net_device,
+				   struct hv_device *device,
 				   struct vmpacket_descriptor *packet)
 {
-	struct netvsc_device *net_device;
 	struct nvsp_message *nvsp_packet;
 	struct hv_netvsc_packet *nvsc_packet;
 	struct net_device *ndev;
 
-	net_device = get_inbound_net_device(device);
-	if (!net_device)
-		return;
 	ndev = net_device->ndev;
 
 	nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
@@ -561,13 +558,13 @@ int netvsc_send(struct hv_device *device,
 }
 
 static void netvsc_send_recv_completion(struct hv_device *device,
+					struct netvsc_device *net_device,
 					u64 transaction_id, u32 status)
 {
 	struct nvsp_message recvcompMessage;
 	int retries = 0;
 	int ret;
 	struct net_device *ndev;
-	struct netvsc_device *net_device = hv_get_drvdata(device);
 
 	ndev = net_device->ndev;
 
@@ -653,14 +650,15 @@ static void netvsc_receive_completion(void *context)
 
 	/* Send a receive completion for the xfer page packet */
 	if (fsend_receive_comp)
-		netvsc_send_recv_completion(device, transaction_id, status);
+		netvsc_send_recv_completion(device, net_device, transaction_id,
+					status);
 
 }
 
-static void netvsc_receive(struct hv_device *device,
-			    struct vmpacket_descriptor *packet)
+static void netvsc_receive(struct netvsc_device *net_device,
+			struct hv_device *device,
+			struct vmpacket_descriptor *packet)
 {
-	struct netvsc_device *net_device;
 	struct vmtransfer_page_packet_header *vmxferpage_packet;
 	struct nvsp_message *nvsp_packet;
 	struct hv_netvsc_packet *netvsc_packet = NULL;
@@ -673,9 +671,6 @@ static void netvsc_receive(struct hv_device *device,
 
 	LIST_HEAD(listHead);
 
-	net_device = get_inbound_net_device(device);
-	if (!net_device)
-		return;
 	ndev = net_device->ndev;
 
 	/*
@@ -741,7 +736,7 @@ static void netvsc_receive(struct hv_device *device,
 		spin_unlock_irqrestore(&net_device->recv_pkt_list_lock,
 				       flags);
 
-		netvsc_send_recv_completion(device,
+		netvsc_send_recv_completion(device, net_device,
 					    vmxferpage_packet->d.trans_id,
 					    NVSP_STAT_FAIL);
 
@@ -825,11 +820,13 @@ static void netvsc_channel_cb(void *context)
 				desc = (struct vmpacket_descriptor *)buffer;
 				switch (desc->type) {
 				case VM_PKT_COMP:
-					netvsc_send_completion(device, desc);
+					netvsc_send_completion(net_device,
+								device, desc);
 					break;
 
 				case VM_PKT_DATA_USING_XFER_PAGES:
-					netvsc_receive(device, desc);
+					netvsc_receive(net_device,
+							device, desc);
 					break;
 
 				default:
-- 
1.7.4.1

[PATCH 3/3] Drivers: net: hyperv: Cleanup the netvsc receive callback functio

[K. Y. Srinivasan]

Get rid of the buffer allocation in the receive path for normal packets.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h |    2 ++
 drivers/net/hyperv/netvsc.c     |   33 ++++++++++-----------------------
 2 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 7645ba3..01a16ea 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -506,6 +506,8 @@ struct netvsc_device {
 
 	/* Holds rndis device info */
 	void *extension;
+	/* The recive buffer for this device */
+	unsigned char cb_buffer[NETVSC_PACKET_SIZE];
 };
 
 /* NdisInitialize message */
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7fa2bba..9a0e9c6 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -795,22 +795,16 @@ static void netvsc_channel_cb(void *context)
 	struct netvsc_device *net_device;
 	u32 bytes_recvd;
 	u64 request_id;
-	unsigned char *packet;
 	struct vmpacket_descriptor *desc;
 	unsigned char *buffer;
 	int bufferlen = NETVSC_PACKET_SIZE;
 	struct net_device *ndev;
 
-	packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
-			 GFP_ATOMIC);
-	if (!packet)
-		return;
-	buffer = packet;
-
 	net_device = get_inbound_net_device(device);
 	if (!net_device)
-		goto out;
+		return;
 	ndev = net_device->ndev;
+	buffer = net_device->cb_buffer;
 
 	do {
 		ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
@@ -838,23 +832,16 @@ static void netvsc_channel_cb(void *context)
 					break;
 				}
 
-				/* reset */
-				if (bufferlen > NETVSC_PACKET_SIZE) {
-					kfree(buffer);
-					buffer = packet;
-					bufferlen = NETVSC_PACKET_SIZE;
-				}
 			} else {
-				/* reset */
-				if (bufferlen > NETVSC_PACKET_SIZE) {
-					kfree(buffer);
-					buffer = packet;
-					bufferlen = NETVSC_PACKET_SIZE;
-				}
-
+				/*
+				 * We are done for this pass.
+				 */
 				break;
 			}
+
 		} else if (ret == -ENOBUFS) {
+			if (bufferlen > NETVSC_PACKET_SIZE)
+				kfree(buffer);
 			/* Handle large packet */
 			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 			if (buffer == NULL) {
@@ -869,8 +856,8 @@ static void netvsc_channel_cb(void *context)
 		}
 	} while (1);
 
-out:
-	kfree(buffer);
+	if (bufferlen > NETVSC_PACKET_SIZE)
+		kfree(buffer);
 	return;
 }
 
-- 
1.7.4.1

[PATCH 3/3] Drivers: net: hyperv: Cleanup the netvsc receive callback functio

[K. Y. Srinivasan]

Get rid of the buffer allocation in the receive path for normal packets.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h |    2 ++
 drivers/net/hyperv/netvsc.c     |   33 ++++++++++-----------------------
 2 files changed, 12 insertions(+), 23 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 7645ba3..01a16ea 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -506,6 +506,8 @@ struct netvsc_device {
 
 	/* Holds rndis device info */
 	void *extension;
+	/* The recive buffer for this device */
+	unsigned char cb_buffer[NETVSC_PACKET_SIZE];
 };
 
 /* NdisInitialize message */
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7fa2bba..9a0e9c6 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -795,22 +795,16 @@ static void netvsc_channel_cb(void *context)
 	struct netvsc_device *net_device;
 	u32 bytes_recvd;
 	u64 request_id;
-	unsigned char *packet;
 	struct vmpacket_descriptor *desc;
 	unsigned char *buffer;
 	int bufferlen = NETVSC_PACKET_SIZE;
 	struct net_device *ndev;
 
-	packet = kzalloc(NETVSC_PACKET_SIZE * sizeof(unsigned char),
-			 GFP_ATOMIC);
-	if (!packet)
-		return;
-	buffer = packet;
-
 	net_device = get_inbound_net_device(device);
 	if (!net_device)
-		goto out;
+		return;
 	ndev = net_device->ndev;
+	buffer = net_device->cb_buffer;
 
 	do {
 		ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen,
@@ -838,23 +832,16 @@ static void netvsc_channel_cb(void *context)
 					break;
 				}
 
-				/* reset */
-				if (bufferlen > NETVSC_PACKET_SIZE) {
-					kfree(buffer);
-					buffer = packet;
-					bufferlen = NETVSC_PACKET_SIZE;
-				}
 			} else {
-				/* reset */
-				if (bufferlen > NETVSC_PACKET_SIZE) {
-					kfree(buffer);
-					buffer = packet;
-					bufferlen = NETVSC_PACKET_SIZE;
-				}
-
+				/*
+				 * We are done for this pass.
+				 */
 				break;
 			}
+
 		} else if (ret == -ENOBUFS) {
+			if (bufferlen > NETVSC_PACKET_SIZE)
+				kfree(buffer);
 			/* Handle large packet */
 			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
 			if (buffer == NULL) {
@@ -869,8 +856,8 @@ static void netvsc_channel_cb(void *context)
 		}
 	} while (1);
 
-out:
-	kfree(buffer);
+	if (bufferlen > NETVSC_PACKET_SIZE)
+		kfree(buffer);
 	return;
 }
 
-- 
1.7.4.1

Re: [PATCH 0/3] Drivers: net: hyperv: Cleanup the hyper-V networking code

[David Miller]

From: "K. Y. Srinivasan" <kys@microsoft.com>
Date: Sun, 16 Feb 2014 16:38:03 -0800

> Get rid of some unnecessary code and some general cleanup.
> 
> K. Y. Srinivasan (3):
>   Drivers: net: hyperv: Get rid of the rndis_filter_packet structure
>   Drivers: net: hyperv: Cleanup the receive path
>   Drivers: net: hyperv: Cleanup the netvsc receive callback functio

Series applied to net-next, thanks.