usb: Add support for rndis uplink aggregation

RNDIS protocol supports data aggregation on uplink and can help
reduce mips by reducing number of interrupts on device. Throughput
also improved by 20-30%. Aggregation is disabled by setting
aggregation packet size to 1. To help better UL throughput, set
as ul aggregation support to 3 rndis packets by default. It can be
configured via module parameter: rndis_ul_max_pkt_per_xfer.

Change-Id: I0b62a21a5c3ceb6b04933d0d6da33301dbafe493
Signed-off-by: Vamsi Krishna <vskrishn@codeaurora.org>
Signed-off-by: Xerox Lin <xerox_lin@htc.com>

5 files changed, 111 insertions, 18 deletions

diff --git a/drivers/usb/gadget/function/f_rndis.c b/drivers/usb/gadget/function/f_rndis.c
index e587767e374c..479fa2938412 100644
--- a/drivers/usb/gadget/function/f_rndis.c
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -70,6 +70,16 @@
  *   - MS-Windows drivers sometimes emit undocumented requests.
  */
 
+static bool rndis_multipacket_dl_disable;
+module_param(rndis_multipacket_dl_disable, bool, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(rndis_multipacket_dl_disable,
+	"Disable RNDIS Multi-packet support in DownLink");
+
+static unsigned int rndis_ul_max_pkt_per_xfer = 3;
+module_param(rndis_ul_max_pkt_per_xfer, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(rndis_ul_max_pkt_per_xfer,
+       "Maximum packets per transfer for UL aggregation");
+
 struct f_rndis {
 	struct gether			port;
 	u8				ctrl_id, data_id;
@@ -792,6 +802,7 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
 
 	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
 	rndis_set_host_mac(rndis->params, rndis->ethaddr);
+	rndis_set_max_pkt_xfer(rndis->config, rndis_ul_max_pkt_per_xfer);
 
 	if (rndis->manufacturer && rndis->vendorID &&
 			rndis_set_param_vendor(rndis->params, rndis->vendorID,
@@ -978,6 +989,7 @@ static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
 	rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
 	rndis->port.wrap = rndis_add_header;
 	rndis->port.unwrap = rndis_rm_hdr;
+	rndis->port.ul_max_pkts_per_xfer = rndis_ul_max_pkt_per_xfer;
 
 	rndis->port.func.name = "rndis";
 	/* descriptors are per-instance copies */
diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 27163e816be4..c3ecff8aff8a 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -42,6 +42,16 @@
 
 #include "rndis.h"
 
+int rndis_ul_max_pkt_per_xfer_rcvd;
+module_param(rndis_ul_max_pkt_per_xfer_rcvd, int, S_IRUGO);
+MODULE_PARM_DESC(rndis_ul_max_pkt_per_xfer_rcvd,
+		"Max num of REMOTE_NDIS_PACKET_MSGs received in a single transfer");
+
+int rndis_ul_max_xfer_size_rcvd;
+module_param(rndis_ul_max_xfer_size_rcvd, int, S_IRUGO);
+MODULE_PARM_DESC(rndis_ul_max_xfer_size_rcvd,
+		"Max size of bus transfer received");
+
 
 /* The driver for your USB chip needs to support ep0 OUT to work with
  * RNDIS, plus all three CDC Ethernet endpoints (interrupt not optional).
@@ -579,12 +589,12 @@ static int rndis_init_response(struct rndis_params *params,
 	resp->MinorVersion = cpu_to_le32(RNDIS_MINOR_VERSION);
 	resp->DeviceFlags = cpu_to_le32(RNDIS_DF_CONNECTIONLESS);
 	resp->Medium = cpu_to_le32(RNDIS_MEDIUM_802_3);
-	resp->MaxPacketsPerTransfer = cpu_to_le32(1);
-	resp->MaxTransferSize = cpu_to_le32(
-		  params->dev->mtu
+	resp->MaxPacketsPerTransfer = cpu_to_le32(params->max_pkt_per_xfer);
+	resp->MaxTransferSize = cpu_to_le32(params->max_pkt_per_xfer *
+		(params->dev->mtu
 		+ sizeof(struct ethhdr)
 		+ sizeof(struct rndis_packet_msg_type)
-		+ 22);
+		+ 22));
 	resp->PacketAlignmentFactor = cpu_to_le32(0);
 	resp->AFListOffset = cpu_to_le32(0);
 	resp->AFListSize = cpu_to_le32(0);
@@ -964,6 +974,8 @@ int rndis_set_param_dev(struct rndis_params *params, struct net_device *dev,
 	params->dev = dev;
 	params->filter = cdc_filter;
 
+	rndis_ul_max_xfer_size_rcvd = 0;
+	rndis_ul_max_pkt_per_xfer_rcvd = 0;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rndis_set_param_dev);
@@ -996,6 +1008,13 @@ int rndis_set_param_medium(struct rndis_params *params, u32 medium, u32 speed)
 }
 EXPORT_SYMBOL_GPL(rndis_set_param_medium);
 
+void rndis_set_max_pkt_xfer(u8 configNr, u8 max_pkt_per_xfer)
+{
+	pr_debug("%s:\n", __func__);
+
+	rndis_per_dev_params[configNr].max_pkt_per_xfer = max_pkt_per_xfer;
+}
+
 void rndis_add_hdr(struct sk_buff *skb)
 {
 	struct rndis_packet_msg_type *header;
@@ -1068,23 +1087,73 @@ int rndis_rm_hdr(struct gether *port,
 			struct sk_buff *skb,
 			struct sk_buff_head *list)
 {
-	/* tmp points to a struct rndis_packet_msg_type */
-	__le32 *tmp = (void *)skb->data;
+	int num_pkts = 1;
 
-	/* MessageType, MessageLength */
-	if (cpu_to_le32(RNDIS_MSG_PACKET)
-			!= get_unaligned(tmp++)) {
-		dev_kfree_skb_any(skb);
-		return -EINVAL;
-	}
-	tmp++;
+	if (skb->len > rndis_ul_max_xfer_size_rcvd)
+		rndis_ul_max_xfer_size_rcvd = skb->len;
+
+	while (skb->len) {
+		struct rndis_packet_msg_type *hdr;
+		struct sk_buff          *skb2;
+		u32             msg_len, data_offset, data_len;
 
-	/* DataOffset, DataLength */
-	if (!skb_pull(skb, get_unaligned_le32(tmp++) + 8)) {
-		dev_kfree_skb_any(skb);
-		return -EOVERFLOW;
+		/* some rndis hosts send extra byte to avoid zlp, ignore it */
+		if (skb->len == 1) {
+			dev_kfree_skb_any(skb);
+			return 0;
+		}
+
+		if (skb->len < sizeof *hdr) {
+			pr_err("invalid rndis pkt: skblen:%u hdr_len:%u",
+					skb->len, sizeof *hdr);
+			dev_kfree_skb_any(skb);
+			return -EINVAL;
+		}
+
+		hdr = (void *)skb->data;
+		msg_len = le32_to_cpu(hdr->MessageLength);
+		data_offset = le32_to_cpu(hdr->DataOffset);
+		data_len = le32_to_cpu(hdr->DataLength);
+
+		if (skb->len < msg_len ||
+				((data_offset + data_len + 8) > msg_len)) {
+			pr_err("invalid rndis message: %d/%d/%d/%d, len:%d\n",
+					le32_to_cpu(hdr->MessageType),
+					msg_len, data_offset, data_len, skb->len);
+			dev_kfree_skb_any(skb);
+			return -EOVERFLOW;
+		}
+		if (le32_to_cpu(hdr->MessageType) != RNDIS_MSG_PACKET) {
+			pr_err("invalid rndis message: %d/%d/%d/%d, len:%d\n",
+					le32_to_cpu(hdr->MessageType),
+					msg_len, data_offset, data_len, skb->len);
+			dev_kfree_skb_any(skb);
+			return -EINVAL;
+		}
+
+		skb_pull(skb, data_offset + 8);
+
+		if (msg_len == skb->len) {
+			skb_trim(skb, data_len);
+			break;
+		}
+
+		skb2 = skb_clone(skb, GFP_ATOMIC);
+		if (!skb2) {
+			pr_err("%s:skb clone failed\n", __func__);
+			dev_kfree_skb_any(skb);
+			return -ENOMEM;
+		}
+
+		skb_pull(skb, msg_len - sizeof *hdr);
+		skb_trim(skb2, data_len);
+		skb_queue_tail(list, skb2);
+
+		num_pkts++;
 	}
-	skb_trim(skb, get_unaligned_le32(tmp++));
+
+	if (num_pkts > rndis_ul_max_pkt_per_xfer_rcvd)
+		rndis_ul_max_pkt_per_xfer_rcvd = num_pkts;
 
 	skb_queue_tail(list, skb);
 	return 0;
diff --git a/drivers/usb/gadget/function/rndis.h b/drivers/usb/gadget/function/rndis.h
index ef92eb66d8ad..2b92b745d292 100644
--- a/drivers/usb/gadget/function/rndis.h
+++ b/drivers/usb/gadget/function/rndis.h
@@ -190,6 +190,7 @@ typedef struct rndis_params
 	struct net_device	*dev;
 
 	u32			vendorID;
+	u8			max_pkt_per_xfer;
 	const char		*vendorDescr;
 	void			(*resp_avail)(void *v);
 	void			*v;
@@ -206,6 +207,7 @@ int  rndis_set_param_vendor(struct rndis_params *params, u32 vendorID,
 			    const char *vendorDescr);
 int  rndis_set_param_medium(struct rndis_params *params, u32 medium,
 			     u32 speed);
+void rndis_set_max_pkt_xfer(u8 configNr, u8 max_pkt_per_xfer);
 void rndis_add_hdr(struct sk_buff *skb);
 int rndis_rm_hdr(struct gether *port, struct sk_buff *skb,
 			struct sk_buff_head *list);
diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index 6554322af2c1..0d2860a09f40 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -71,6 +71,7 @@ struct eth_dev {
 	unsigned		qmult;
 
 	unsigned		header_len;
+	unsigned		ul_max_pkts_per_xfer;
 	struct sk_buff		*(*wrap)(struct gether *, struct sk_buff *skb);
 	int			(*unwrap)(struct gether *,
 						struct sk_buff *skb,
@@ -230,9 +231,13 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
 	size += out->maxpacket - 1;
 	size -= size % out->maxpacket;
 
+	if (dev->ul_max_pkts_per_xfer)
+		size *= dev->ul_max_pkts_per_xfer;
+
 	if (dev->port_usb->is_fixed)
 		size = max_t(size_t, size, dev->port_usb->fixed_out_len);
 
+	DBG(dev, "%s: size: %d\n", __func__, size);
 	skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
 	if (skb == NULL) {
 		DBG(dev, "no rx skb\n");
@@ -1077,6 +1082,7 @@ struct net_device *gether_connect(struct gether *link)
 		dev->header_len = link->header_len;
 		dev->unwrap = link->unwrap;
 		dev->wrap = link->wrap;
+		dev->ul_max_pkts_per_xfer = link->ul_max_pkts_per_xfer;
 
 		spin_lock(&dev->lock);
 		dev->port_usb = link;
diff --git a/drivers/usb/gadget/function/u_ether.h b/drivers/usb/gadget/function/u_ether.h
index c77145bd6b5b..7914b4b1ce6c 100644
--- a/drivers/usb/gadget/function/u_ether.h
+++ b/drivers/usb/gadget/function/u_ether.h
@@ -73,6 +73,10 @@ struct gether {
 	bool				is_fixed;
 	u32				fixed_out_len;
 	u32				fixed_in_len;
+	unsigned		ul_max_pkts_per_xfer;
+/* Max number of SKB packets to be used to create Multi Packet RNDIS */
+#define TX_SKB_HOLD_THRESHOLD		3
+	bool				multi_pkt_xfer;
 	bool				supports_multi_frame;
 	struct sk_buff			*(*wrap)(struct gether *port,
 						struct sk_buff *skb);