Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4aaa9c35 authored by Mayank Rana's avatar Mayank Rana Committed by Ajay Agarwal
Browse files

USB: gadget: rndis: Optimize tx path for better performance 



Current rndis header addition and aggregation steps:
1. Increase skb headroom by size of rndis header.
2. Copy skb data with newly created skb having more headroom.
3. Create and add rndis header with it.
4. Again copy skb data with usb request buffer for aggregation purpose.

New optimized steps :
1. Create and copy rndis header directly with usb request buffer
2. Copy skb data with usb request buffer

Above new steps avoids cpu intensive skb operations which reduces CPU
usage and provide better throughput.

This change also assigns completion handle with usb request at the time
of usb request creation instead of assigning everytime before queueing
usb request. Also create debugfs for ether stats.

Change-Id: Ifc64d6a8573f6a24e28c73ef9a19b62649e171cd
Signed-off-by: default avatarMayank Rana <mrana@codeaurora.org>
Signed-off-by: default avatarAjay Agarwal <ajaya@codeaurora.org>
parent 72377357

drivers/usb/gadget/function/f_rndis.c

+21 −0
Original line number Diff line number Diff line
@@ -386,10 +386,31 @@ static struct sk_buff *rndis_add_header(struct gether *port, 
					struct sk_buff *skb)

{

	struct sk_buff *skb2;

	struct rndis_packet_msg_type *header = NULL;

	struct f_rndis *rndis = func_to_rndis(&port->func);



	if (!skb)

		return NULL;



	if (rndis->port.multi_pkt_xfer) {

		if (port->header) {

			header = port->header;

			header->MessageType = cpu_to_le32(RNDIS_MSG_PACKET);

			header->MessageLength = cpu_to_le32(skb->len +

							sizeof(*header));

			header->DataOffset = cpu_to_le32(36);

			header->DataLength = cpu_to_le32(skb->len);

			pr_debug("MessageLength:%d DataLength:%d\n",

						header->MessageLength,

						header->DataLength);

			return skb;

		}



		dev_kfree_skb(skb);

		pr_err("RNDIS header is NULL.\n");

		return NULL;

	}



	skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));

	rndis_add_hdr(skb2);

drivers/usb/gadget/function/u_ether.c

+45 −8
Original line number Diff line number Diff line
@@ -246,6 +246,7 @@ static void defer_kevent(struct eth_dev *dev, int flag) 
}



static void rx_complete(struct usb_ep *ep, struct usb_request *req);

static void tx_complete(struct usb_ep *ep, struct usb_request *req);



static int

rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
@@ -307,7 +308,6 @@ rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags) 


	req->buf = skb->data;

	req->length = size;

	req->complete = rx_complete;

	req->context = skb;



	retval = usb_ep_queue(out, req, gfp_flags);
@@ -410,6 +410,7 @@ static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n) 
{

	unsigned		i;

	struct usb_request	*req;

	bool			usb_in;



	if (!n)

		return -ENOMEM;
@@ -420,10 +421,22 @@ static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n) 
		if (i-- == 0)

			goto extra;

	}



	if (ep->desc->bEndpointAddress & USB_DIR_IN)

		usb_in = true;

	else

		usb_in = false;



	while (i--) {

		req = usb_ep_alloc_request(ep, GFP_ATOMIC);

		if (!req)

			return list_empty(list) ? -ENOMEM : 0;

		/* update completion handler */

		if (usb_in)

			req->complete = tx_complete;

		else

			req->complete = rx_complete;



		list_add(&req->list, list);

	}

	return 0;
@@ -575,7 +588,7 @@ static void eth_work(struct work_struct *work) 


static void tx_complete(struct usb_ep *ep, struct usb_request *req)

{

	struct sk_buff	*skb = req->context;

	struct sk_buff	*skb;

	struct eth_dev	*dev = ep->driver_data;

	struct net_device *net = dev->net;

	struct usb_request *new_req;
@@ -683,6 +696,7 @@ static void tx_complete(struct usb_ep *ep, struct usb_request *req) 
			spin_unlock(&dev->req_lock);

		}

	} else {

		skb = req->context;

		/* Is aggregation already enabled and buffers allocated ? */

		if (dev->port_usb->multi_pkt_xfer && dev->tx_req_bufsize) {

			req->buf = kzalloc(dev->tx_req_bufsize
@@ -725,7 +739,7 @@ static int alloc_tx_buffer(struct eth_dev *dev) 
	list_for_each(act, &dev->tx_reqs) {

		req = container_of(act, struct usb_request, list);

		if (!req->buf)

			req->buf = kmalloc(dev->tx_req_bufsize

			req->buf = kzalloc(dev->tx_req_bufsize

				+ dev->gadget->extra_buf_alloc, GFP_ATOMIC);



		if (!req->buf)
@@ -866,8 +880,19 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, 
	spin_unlock_irqrestore(&dev->req_lock, flags);



	if (multi_pkt_xfer) {

		pr_debug("req->length:%d header_len:%u\n"

				"skb->len:%d skb->data_len:%d\n",

				req->length, dev->header_len,

				skb->len, skb->data_len);

		/* Add RNDIS Header */

		memcpy(req->buf + req->length, dev->port_usb->header,

						dev->header_len);

		/* Increment req length by header size */

		req->length += dev->header_len;

		/* Copy received IP data from SKB */

		memcpy(req->buf + req->length, skb->data, skb->len);

		req->length = req->length + skb->len;

		/* Increment req length by skb data length */

		req->length += skb->len;

		length = req->length;

		dev_kfree_skb_any(skb);
@@ -927,8 +952,6 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, 
		req->context = skb;

	}



	req->complete = tx_complete;



	/* NCM requires no zlp if transfer is dwNtbInMaxSize */

	if (is_fixed && length == fixed_in_len &&

	    (length % in->maxpacket) == 0)
@@ -981,7 +1004,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, 
		spin_lock_irqsave(&dev->req_lock, flags);

		if (list_empty(&dev->tx_reqs))

			netif_start_queue(net);

		list_add(&req->list, &dev->tx_reqs);

		list_add_tail(&req->list, &dev->tx_reqs);

		spin_unlock_irqrestore(&dev->req_lock, flags);

	}

success:
@@ -1443,6 +1466,8 @@ int gether_register_netdev(struct net_device *net) 
	else

		INFO(dev, "MAC %pM\n", dev->dev_mac);



	uether_debugfs_init(dev);



	return status;

}

EXPORT_SYMBOL_GPL(gether_register_netdev);
@@ -1594,6 +1619,11 @@ struct net_device *gether_connect(struct gether *link) 
	if (!dev)

		return ERR_PTR(-EINVAL);



	/* size of rndis_packet_msg_type is 44 */

	link->header = kzalloc(44, GFP_ATOMIC);

	if (!link->header)

		return ERR_PTR(-ENOMEM);



	if (link->in_ep) {

		link->in_ep->driver_data = dev;

		result = usb_ep_enable(link->in_ep);
@@ -1657,8 +1687,12 @@ struct net_device *gether_connect(struct gether *link) 
	}

fail0:

	/* caller is responsible for cleanup on error */

	if (result < 0)

	if (result < 0) {

		kfree(link->header);



		return ERR_PTR(result);

	}



	return dev->net;

}

EXPORT_SYMBOL_GPL(gether_connect);
@@ -1711,6 +1745,9 @@ void gether_disconnect(struct gether *link) 
			spin_lock(&dev->req_lock);

		}

		spin_unlock(&dev->req_lock);

		/* Free rndis header buffer memory */

		kfree(link->header);

		link->header = NULL;

		link->in_ep->desc = NULL;

	}

drivers/usb/gadget/function/u_ether.h

+1 −0
Original line number Diff line number Diff line
@@ -87,6 +87,7 @@ struct gether { 
	/* called on network open/close */

	void				(*open)(struct gether *);

	void				(*close)(struct gether *);

	struct rndis_packet_msg_type	*header;

};



#define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \