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Commit e6b7870e authored by Devdutt Patnaik's avatar Devdutt Patnaik Committed by Azhar Shaikh
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net: usbnet: Add support for IPA s/w bridge 



Add support to bypass linux network stack and pass
IPv4 and IPv6 packets directly to IPA using a s/w bridge.

This helps avoid context switches due to packet processing
in soft IRQ context thereby freeing CPU and improving
thoughput.

Change-Id: I91530d0b27c7dcaba81d7a5e4ca72c22b2917c70
Signed-off-by: default avatarDevdutt Patnaik <dpatnaik@codeaurora.org>
Signed-off-by: default avatarAzhar Shaikh <azhars@codeaurora.org>
parent 2f867742

drivers/net/usb/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -572,4 +572,12 @@ config USB_VL600 


	  http://ubuntuforums.org/showpost.php?p=10589647&postcount=17



config USBNET_IPA_BRIDGE

	tristate "USB to IPA bridge"

	depends on USB_USBNET && IPA

	help

	  Select this if you want to enable USB to IPA bridge.

	  This will pass IP traffic directly to IPA and bypass the network stack.



endif # USB_NET_DRIVERS

drivers/net/usb/usbnet.c

+236 −1
Original line number Diff line number Diff line
@@ -84,11 +84,18 @@ static u8 node_id [ETH_ALEN]; 


static const char driver_name [] = "usbnet";



struct workqueue_struct		*usbnet_wq;

/* use ethtool to change the level for any given device */

static int msg_level = -1;

module_param (msg_level, int, 0);

MODULE_PARM_DESC (msg_level, "Override default message level");



#ifdef CONFIG_USBNET_IPA_BRIDGE

	unsigned int enable_ipa_bridge = 1;

#else

	unsigned int enable_ipa_bridge = 0;

#endif



/*-------------------------------------------------------------------------*/



/* handles CDC Ethernet and many other network "bulk data" interfaces */
@@ -318,6 +325,16 @@ static void __usbnet_status_stop_force(struct usbnet *dev) 
void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)

{

	int	status;

	struct	ipa_tx_meta ipa_meta = {0x0};

	u8	protocol_type = (skb->data[ETH_HLEN] & 0xf0);



	/* Pass IPv4 and IPv6 packets to IPA by peeking into the IP header */

	if (enable_ipa_bridge && (protocol_type == 0x40 ||

				  protocol_type == 0x60)) {

		dev->pusbnet_ipa->stats.rx_ipa_send++;

		odu_bridge_tx_dp(skb, &ipa_meta);

		return;

	}



	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {

		skb_queue_tail(&dev->rxq_pause, skb);
@@ -367,7 +384,6 @@ void usbnet_update_max_qlen(struct usbnet *dev) 
}

EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);





/*-------------------------------------------------------------------------

 *

 * Network Device Driver (peer link to "Host Device", from USB host)
@@ -1293,6 +1309,9 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, 
	unsigned long		flags;

	int retval;



	if (enable_ipa_bridge && dev->txq.qlen >= TX_QLEN(dev))

		goto drop;



	if (skb)

		skb_tx_timestamp(skb);
@@ -1511,6 +1530,20 @@ static void usbnet_bh (unsigned long param) 
 * USB Device Driver support

 *

 *-------------------------------------------------------------------------*/

static void usbnet_ipa_cleanup_rm(void)

{

	int ret;



	ret = ipa_rm_delete_resource(IPA_RM_RESOURCE_ODU_ADAPT_PROD);

	if (ret)

		pr_warn("Resource:IPA_RM_RESOURCE_ODU_ADAPT_PROD del fail %d\n",

			ret);



	ret = ipa_rm_delete_resource(IPA_RM_RESOURCE_ODU_ADAPT_CONS);

	if (ret)

		pr_warn("Resource:IPA_RM_RESOURCE_ODU_ADAPT_CONS del fail %d\n",

			ret);

}



// precondition: never called in_interrupt
@@ -1519,6 +1552,7 @@ void usbnet_disconnect (struct usb_interface *intf) 
	struct usbnet		*dev;

	struct usb_device	*xdev;

	struct net_device	*net;

	int retval = 0;



	dev = usb_get_intfdata(intf);

	usb_set_intfdata(intf, NULL);
@@ -1537,6 +1571,20 @@ void usbnet_disconnect (struct usb_interface *intf) 


	cancel_work_sync(&dev->kevent);



	if (enable_ipa_bridge) {

		retval = odu_bridge_disconnect();

		if (retval)

			dev_dbg(&dev->udev->dev,

				"%s Disconnect from ODU bridge failed.\n",

				__func__);

		retval = odu_bridge_cleanup();

		if (retval)

			dev_dbg(&dev->udev->dev,

				"%s ODU bridge cleanup failed.\n",

				__func__);

		usbnet_ipa_cleanup_rm();

		kfree(dev->pusbnet_ipa);

	}

	usb_scuttle_anchored_urbs(&dev->deferred);



	if (dev->driver_info->unbind)
@@ -1573,6 +1621,145 @@ static struct device_type wwan_type = { 
	.name	= "wwan",

};



static void usbnet_ipa_rm_notify(void *user_data, enum ipa_rm_event event,

				 unsigned long data)

{

	pr_debug(" %s IPA RM Evt: %d\n", __func__, event);

}



static int usbnet_ipa_rm_cons_request(void)

{

	/* Do Nothing*/

	return 0;

}



static int usbnet_ipa_rm_cons_release(void)

{

	/* Do Nothing*/

	return 0;

}



static int usbnet_ipa_setup_rm(struct usbnet *dev)

{

	struct ipa_rm_create_params create_params = {0};

	int ret;



	create_params.name = IPA_RM_RESOURCE_ODU_ADAPT_PROD;

	create_params.reg_params.user_data = dev;

	create_params.reg_params.notify_cb = usbnet_ipa_rm_notify;

	create_params.floor_voltage = IPA_VOLTAGE_SVS;



	ret = ipa_rm_create_resource(&create_params);

	if (ret) {

		dev_dbg(&dev->udev->dev,

			"Create ODU PROD RM resource failed: %d\n", ret);

		goto prod_fail;

	}



	memset(&create_params, 0, sizeof(create_params));

	create_params.name = IPA_RM_RESOURCE_ODU_ADAPT_CONS;

	create_params.request_resource = usbnet_ipa_rm_cons_request;

	create_params.release_resource = usbnet_ipa_rm_cons_release;

	create_params.floor_voltage = IPA_VOLTAGE_SVS;



	ret = ipa_rm_create_resource(&create_params);

	if (ret) {

		dev_dbg(&dev->udev->dev,

			"Create ODU CONC RM resource failed: %d\n", ret);

		goto delete_prod;

	}



	return ret;



delete_prod:

	ipa_rm_delete_resource(IPA_RM_RESOURCE_ODU_ADAPT_PROD);



prod_fail:

	return ret;

}



static void usbnet_ipa_tx_dp_cb(void *priv, enum ipa_dp_evt_type evt,

				unsigned long data)

{

	struct usbnet *dev = priv;

	struct usbnet_ipa_ctx *usbnet_ipa = dev->pusbnet_ipa;

	struct sk_buff *skb = (struct sk_buff *)data;

	int status;



	switch (evt) {

	case IPA_RECEIVE:

		/* Deliver SKB to network adapter */

		usbnet_ipa->stats.rx_ipa_excep++;

		skb->dev = dev->net;

		skb->protocol = eth_type_trans(skb, skb->dev);

		status = netif_rx_ni(skb);

		if (status != NET_RX_SUCCESS)

			pr_err("ERROR sending to nw stack %d\n", status);

		break;



	case IPA_WRITE_DONE:

		/* SKB send to IPA, safe to free */

		usbnet_ipa->stats.rx_ipa_write_done++;

		dev->net->stats.rx_packets++;

		dev->net->stats.rx_bytes += skb->len;

		dev_kfree_skb(skb);

		break;



	default:

		pr_err("%s Invalid event from IPA\n", __func__);

		break;

	}

}



static void usbnet_ipa_tx_dl(void *priv, struct sk_buff *skb)

{

	struct usbnet *dev = priv;

	struct usbnet_ipa_ctx *usbnet_ipa = dev->pusbnet_ipa;

	netdev_tx_t ret = __NETDEV_TX_MIN;



	ret = usbnet_start_xmit(skb, dev->net);



	if (ret != NETDEV_TX_OK) {

		pr_err("%s usbnet_ipa_tx_dl() failed xmit returned %d\n",

		       __func__, ret);

		usbnet_ipa->stats.tx_ipa_send_err++;

		dev_kfree_skb_any(skb);

	} else {

		usbnet_ipa->stats.tx_ipa_send++;

	}

}



static int usbnet_ipa_set_perf_level(struct usbnet *dev)

{

	struct ipa_rm_perf_profile profile;

	int ret = 0;



	memset(&profile, 0, sizeof(profile));



	if (dev->udev->speed == USB_SPEED_SUPER)

		profile.max_supported_bandwidth_mbps = 800;

	else

		profile.max_supported_bandwidth_mbps = 400;



	ret = ipa_rm_set_perf_profile(IPA_RM_RESOURCE_ODU_ADAPT_PROD,

				      &profile);

	if (ret) {

		pr_err("Err to set BW: IPA_RM_RESOURCE_ODU_ADAPT_PROD err:%d\n",

		       ret);

		return ret;

	}



	ret = ipa_rm_set_perf_profile(IPA_RM_RESOURCE_ODU_ADAPT_CONS,

				      &profile);

	if (ret) {

		pr_err("Err to set BW: IPA_RM_RESOURCE_ODU_ADAPT_CONS err:%d\n",

		       ret);

		return ret;

	}



	return ret;

}



int

usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)

{
@@ -1584,6 +1771,10 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) 
	int				status;

	const char			*name;

	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);

	struct usbnet_ipa_ctx *usbnet_ipa = NULL;

	struct odu_bridge_params *params_ptr, params;



	params_ptr = &params;



	/* usbnet already took usb runtime pm, so have to enable the feature

	 * for usb interface, otherwise usb_autopm_get_interface may return
@@ -1736,6 +1927,41 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) 
		   dev->driver_info->description,

		   net->dev_addr);



	if (enable_ipa_bridge) {

		/* Init IPA Context */

		usbnet_ipa = kzalloc(sizeof(*usbnet_ipa), GFP_KERNEL);

		if (!usbnet_ipa) {

			status = -ENOMEM;

			goto out4;

		}



		dev->pusbnet_ipa = usbnet_ipa;

		dev->ipa_free_desc_cnt = USBNET_IPA_SYS_PIPE_MAX_PKTS_DESC;

		dev->ipa_high_watermark = USBNET_IPA_SYS_PIPE_MAX_PKTS_DESC;

		dev->ipa_low_watermark = USBNET_IPA_SYS_PIPE_MIN_PKTS_DESC;



		status = usbnet_ipa_setup_rm(dev);

		if (status) {

			pr_err("USBNET: IPA Setup RM Failed\n");

			goto out4;

		}



		/* Initialize the ODU bridge driver now: odu_bridge_init()*/

		params_ptr->netdev_name = net->name;

		params_ptr->priv = dev;

		params.tx_dp_notify = usbnet_ipa_tx_dp_cb;

		params_ptr->send_dl_skb = (void *)&usbnet_ipa_tx_dl;

		memcpy(params_ptr->device_ethaddr, net->dev_addr, 6);

		params_ptr->ipa_desc_size = (dev->ipa_high_watermark + 1) *

					sizeof(struct sps_iovec);



		status = odu_bridge_init(params_ptr);

		if (status) {

			pr_err("Couldnt initialize ODU_Bridge Driver\n");

			goto out4;

		}

	}



	// ok, it's ready to go.

	usb_set_intfdata (udev, dev);
@@ -1744,6 +1970,15 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) 
	if (dev->driver_info->flags & FLAG_LINK_INTR)

		usbnet_link_change(dev, 0, 0);



	if (enable_ipa_bridge) {

		status = odu_bridge_connect();

		if (status)

			pr_err("Could not connect to ODU bridge %d\n",

			       status);

		else

			usbnet_ipa_set_perf_level(dev);

	}



	return 0;



out5:

include/linux/usb/usbnet.h

+27 −0
Original line number Diff line number Diff line
@@ -22,10 +22,33 @@ 
#ifndef	__LINUX_USB_USBNET_H

#define	__LINUX_USB_USBNET_H



#include <linux/ipa.h>



#define USBNET_IPA_SYS_PIPE_MAX_PKTS_DESC 160

#define USBNET_IPA_SYS_PIPE_MIN_PKTS_DESC 5

#define USBNET_IPA_SYS_PIPE_DNE_PKTS (USBNET_IPA_SYS_PIPE_MAX_PKTS_DESC*2)



struct usbnet_ipa_stats {

	/* RX Side */

	uint64_t rx_ipa_excep;

	uint64_t rx_ipa_write_done;

	uint64_t rx_ipa_send;

	uint64_t rx_ipa_send_fail;



	/* TX Side*/

	uint64_t tx_ipa_send;

	uint64_t tx_ipa_send_err;

};



struct usbnet_ipa_ctx {

	struct usbnet_ipa_stats stats;

};



/* interface from usbnet core to each USB networking link we handle */

struct usbnet {

	/* housekeeping */

	struct usb_device	*udev;

	struct usbnet_ipa_ctx	*pusbnet_ipa;

	struct usb_interface	*intf;

	struct driver_info	*driver_info;

	const char		*driver_name;
@@ -79,6 +102,10 @@ struct usbnet { 
#		define EVENT_RX_KILL	10

#		define EVENT_LINK_CHANGE	11

#		define EVENT_SET_RX_MODE	12



	u16 ipa_free_desc_cnt;

	u16 ipa_high_watermark;

	u16 ipa_low_watermark;

};



static inline struct usb_driver *driver_of(struct usb_interface *intf)