FreeRTOS/Demo/CORTEX_A9_Zynq_ZC702/RTOSDemo/src/lwIP_Demo/lwIP_port/netif/xemacpsif.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright notice,
  *    this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  * OF SUCH DAMAGE.
  *
  * This file is part of the lwIP TCP/IP stack.
  *
  * Author: Adam Dunkels <adam@sics.se>
  *
  */

 /*
  * Copyright (c) 2010-2013 Xilinx, Inc.  All rights reserved.
  *
  * Xilinx, Inc.
  * XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
  * COURTESY TO YOU.  BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS
  * ONE POSSIBLE   IMPLEMENTATION OF THIS FEATURE, APPLICATION OR
  * STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION
  * IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE
  * FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.
  * XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO
  * THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO
  * ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE
  * FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY
  * AND FITNESS FOR A PARTICULAR PURPOSE.
  *
  */

 #include <stdio.h>
 #include <string.h>

 #include <xparameters.h>
 #include "lwipopts.h"
 #include "xlwipconfig.h"
 #include "lwip/opt.h"
 #include "lwip/def.h"
 #include "lwip/mem.h"
 #include "lwip/pbuf.h"
 #include "lwip/sys.h"
 #include "lwip/stats.h"
 #include "lwip/igmp.h"

 #include "netif/etharp.h"
 #include "netif/xemacpsif.h"
 #include "netif/xadapter.h"
 #include "netif/xpqueue.h"
 #include "xparameters.h"
 #include "xuartps.h"
 #include "xscugic.h"
 #include "xemacps.h"


 /* Define those to better describe your network interface. */
 #define IFNAME0 't'
 #define IFNAME1 'e'

 #if LWIP_IGMP
 static err_t xemacpsif_mac_filter_update (struct netif *netif,
 							struct ip_addr *group, u8_t action);

 static u8_t xemacps_mcast_entry_mask = 0;
 #endif

 XEmacPs_Config *mac_config;
 struct netif *NetIf;
 void FreeTxPBufs(void);
 /*
  * this function is always called with interrupts off
  * this function also assumes that there are available BD's
  */
 static err_t _unbuffered_low_level_output(xemacpsif_s *xemacpsif,
 													struct pbuf *p)
 {
     	XStatus status = 0;

 #if ETH_PAD_SIZE
 	pbuf_header(p, -ETH_PAD_SIZE);	/* drop the padding word */
 #endif
 	status = emacps_sgsend(xemacpsif, p);
 	if (status != XST_SUCCESS) {
 #if LINK_STATS
 	lwip_stats.link.drop++;
 #endif
 	}

 #if ETH_PAD_SIZE
 	pbuf_header(p, ETH_PAD_SIZE);	/* reclaim the padding word */
 #endif

 #if LINK_STATS
 	lwip_stats.link.xmit++;
 #endif /* LINK_STATS */

 	return ERR_OK;

 }

 /*
  * low_level_output():
  *
  * Should do the actual transmission of the packet. The packet is
  * contained in the pbuf that is passed to the function. This pbuf
  * might be chained.
  *
  */

 static err_t low_level_output(struct netif *netif, struct pbuf *p)
 {
 	SYS_ARCH_DECL_PROTECT(lev);
         err_t err;

 	struct xemac_s *xemac = (struct xemac_s *)(netif->state);
 	xemacpsif_s *xemacpsif = (xemacpsif_s *)(xemac->state);

 	SYS_ARCH_PROTECT(lev);


 	/* check if space is available to send */
         if (is_tx_space_available(xemacpsif)) {
 		_unbuffered_low_level_output(xemacpsif, p);
 		err = ERR_OK;
 	} else {
 #if LINK_STATS
 		lwip_stats.link.drop++;
 #endif
 		print("pack dropped, no space\r\n");
 		err = ERR_MEM;
 	}


 	SYS_ARCH_UNPROTECT(lev);
 	return err;
 }

 /*
  * low_level_input():
  *
  * Should allocate a pbuf and transfer the bytes of the incoming
  * packet from the interface into the pbuf.
  *
  */
 static struct pbuf * low_level_input(struct netif *netif)
 {
 	struct xemac_s *xemac = (struct xemac_s *)(netif->state);
 	xemacpsif_s *xemacpsif = (xemacpsif_s *)(xemac->state);
 	struct pbuf *p;

 	/* see if there is data to process */
 	if (pq_qlength(xemacpsif->recv_q) == 0)
 		return NULL;

 	/* return one packet from receive q */
 	p = (struct pbuf *)pq_dequeue(xemacpsif->recv_q);
 	return p;
 }

 /*
  * xemacpsif_output():
  *
  * This function is called by the TCP/IP stack when an IP packet
  * should be sent. It calls the function called low_level_output() to
  * do the actual transmission of the packet.
  *
  */

 static err_t xemacpsif_output(struct netif *netif, struct pbuf *p,
 		struct ip_addr *ipaddr)
 {
 	/* resolve hardware address, then send (or queue) packet */
 	return etharp_output(netif, p, ipaddr);
 }

 /*
  * xemacpsif_input():
  *
  * This function should be called when a packet is ready to be read
  * from the interface. It uses the function low_level_input() that
  * should handle the actual reception of bytes from the network
  * interface.
  *
  * Returns the number of packets read (max 1 packet on success,
  * 0 if there are no packets)
  *
  */

 int xemacpsif_input(struct netif *netif)
 {
 	struct eth_hdr *ethhdr;
 	struct pbuf *p;
 	SYS_ARCH_DECL_PROTECT(lev);

 #ifdef OS_IS_FREERTOS
 	while (1)
 #endif
 	{
 	/* move received packet into a new pbuf */
 	SYS_ARCH_PROTECT(lev);
 	p = low_level_input(netif);
 	SYS_ARCH_UNPROTECT(lev);

 	/* no packet could be read, silently ignore this */
 	if (p == NULL) {
 		return 0;
 	}

 	/* points to packet payload, which starts with an Ethernet header */
 	ethhdr = p->payload;

 #if LINK_STATS
 	lwip_stats.link.recv++;
 #endif /* LINK_STATS */

 	switch (htons(ethhdr->type)) {
 		/* IP or ARP packet? */
 		case ETHTYPE_IP:
 		case ETHTYPE_ARP:
 #if PPPOE_SUPPORT
 			/* PPPoE packet? */
 		case ETHTYPE_PPPOEDISC:
 		case ETHTYPE_PPPOE:
 #endif /* PPPOE_SUPPORT */
 			/* full packet send to tcpip_thread to process */
 			if (netif->input(p, netif) != ERR_OK) {
 				LWIP_DEBUGF(NETIF_DEBUG, ("xemacpsif_input: IP input error\r\n"));
 				pbuf_free(p);
 				p = NULL;
 			}
 			break;

 		default:
 			pbuf_free(p);
 			p = NULL;
 			break;
 	}
 	}

 	return 1;
 }


 static err_t low_level_init(struct netif *netif)
 {
 	unsigned mac_address = (unsigned)(netif->state);
 	struct xemac_s *xemac;
 	xemacpsif_s *xemacpsif;
 	u32 dmacrreg;

 	int Status = XST_SUCCESS;

 	NetIf = netif;

 	xemacpsif = mem_malloc(sizeof *xemacpsif);
 	if (xemacpsif == NULL) {
 		LWIP_DEBUGF(NETIF_DEBUG, ("xemacpsif_init: out of memory\r\n"));
 		return ERR_MEM;
 	}

 	xemac = mem_malloc(sizeof *xemac);
 	if (xemac == NULL) {
 		LWIP_DEBUGF(NETIF_DEBUG, ("xemacpsif_init: out of memory\r\n"));
 		return ERR_MEM;
 	}

 	xemac->state = (void *)xemacpsif;
 	xemac->topology_index = xtopology_find_index(mac_address);
 	xemac->type = xemac_type_emacps;

 	xemacpsif->send_q = NULL;
 	xemacpsif->recv_q = pq_create_queue();
 	if (!xemacpsif->recv_q)
 		return ERR_MEM;

 	/* maximum transfer unit */
 	netif->mtu = XEMACPS_MTU - XEMACPS_HDR_SIZE;

 #if LWIP_IGMP
 	netif->igmp_mac_filter = xemacpsif_mac_filter_update;
 #endif

 	netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP |
 											NETIF_FLAG_LINK_UP;

 #if LWIP_IGMP
 	netif->flags |= NETIF_FLAG_IGMP;
 #endif

 #if !NO_SYS
 	sys_sem_new(&xemac->sem_rx_data_available, 0);
 #endif
 	/* obtain config of this emac */
 	mac_config = (XEmacPs_Config *)xemacps_lookup_config((unsigned)netif->state);

 	Status = XEmacPs_CfgInitialize(&xemacpsif->emacps, mac_config,
 						mac_config->BaseAddress);
 	if (Status != XST_SUCCESS) {
 		xil_printf("In %s:EmacPs Configuration Failed....\r\n", __func__);
 	}

 	/* initialize the mac */
 	init_emacps(xemacpsif, netif);

 	dmacrreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
 														XEMACPS_DMACR_OFFSET);
 	dmacrreg = dmacrreg | (0x00000010);
 	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
 											XEMACPS_DMACR_OFFSET, dmacrreg);

 	setup_isr(xemac);
 	init_dma(xemac);
 	start_emacps(xemacpsif);

 	/* replace the state in netif (currently the emac baseaddress)
 	 * with the mac instance pointer.
 	 */
 	netif->state = (void *)xemac;

 	return ERR_OK;
 }

 void HandleEmacPsError(struct xemac_s *xemac)
 {
 	xemacpsif_s   *xemacpsif;
 	int Status = XST_SUCCESS;
 	u32 dmacrreg;

 	SYS_ARCH_DECL_PROTECT(lev);
 	SYS_ARCH_PROTECT(lev);

 	FreeTxRxPBufs();
 	xemacpsif = (xemacpsif_s *)(xemac->state);
 	Status = XEmacPs_CfgInitialize(&xemacpsif->emacps, mac_config,
 						mac_config->BaseAddress);
 	if (Status != XST_SUCCESS) {
 		xil_printf("In %s:EmacPs Configuration Failed....\r\n", __func__);
 	}
 	/* initialize the mac */
 	init_emacps_on_error(xemacpsif, NetIf);
 	dmacrreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
 														XEMACPS_DMACR_OFFSET);
 	dmacrreg = dmacrreg | (0x01000000);
 	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
 											XEMACPS_DMACR_OFFSET, dmacrreg);
 	setup_isr(xemac);
 	init_dma(xemac);
 	start_emacps(xemacpsif);

 	SYS_ARCH_UNPROTECT(lev);
 }

 void HandleTxErrors(struct xemac_s *xemac)
 {
 	xemacpsif_s   *xemacpsif;
 	u32 netctrlreg;

 	SYS_ARCH_DECL_PROTECT(lev);
 	SYS_ARCH_PROTECT(lev);
 	xemacpsif = (xemacpsif_s *)(xemac->state);
 	netctrlreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
 												XEMACPS_NWCTRL_OFFSET);
     netctrlreg = netctrlreg & (~XEMACPS_NWCTRL_TXEN_MASK);
 	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
 									XEMACPS_NWCTRL_OFFSET, netctrlreg);
 	FreeOnlyTxPBufs();

 	clean_dma_txdescs(xemac);
 	netctrlreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
 													XEMACPS_NWCTRL_OFFSET);
 	netctrlreg = netctrlreg | (XEMACPS_NWCTRL_TXEN_MASK);
 	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
 										XEMACPS_NWCTRL_OFFSET, netctrlreg);
 	SYS_ARCH_UNPROTECT(lev);
 }


 #if LWIP_IGMP
 static err_t xemacpsif_mac_filter_update (struct netif *netif, struct ip_addr *group,
 								u8_t action)
 {
 	return 0;
 }
 #endif

 /*
  * xemacpsif_init():
  *
  * Should be called at the beginning of the program to set up the
  * network interface. It calls the function low_level_init() to do the
  * actual setup of the hardware.
  *
  */

 err_t xemacpsif_init(struct netif *netif)
 {
 #if LWIP_SNMP
 	/* ifType ethernetCsmacd(6) @see RFC1213 */
 	netif->link_type = 6;
 	/* your link speed here */
 	netif->link_speed = ;
 	netif->ts = 0;
 	netif->ifinoctets = 0;
 	netif->ifinucastpkts = 0;
 	netif->ifinnucastpkts = 0;
 	netif->ifindiscards = 0;
 	netif->ifoutoctets = 0;
 	netif->ifoutucastpkts = 0;
 	netif->ifoutnucastpkts = 0;
 	netif->ifoutdiscards = 0;
 #endif

 	netif->name[0] = IFNAME0;
 	netif->name[1] = IFNAME1;
 	netif->output = xemacpsif_output;
 	netif->linkoutput = low_level_output;

 	low_level_init(netif);
 	return ERR_OK;
 }

 /*
  * xemacpsif_resetrx_on_no_rxdata():
  *
  * Should be called by the user at regular intervals, typically
  * from a timer (100 msecond). This is to provide a SW workaround
  * for the HW bug (SI #692601). Please refer to the function header
  * for the function resetrx_on_no_rxdata in xemacpsif_dma.c to
  * know more about the SI.
  *
  */

 void xemacpsif_resetrx_on_no_rxdata(struct netif *netif)
 {
 	struct xemac_s *xemac = (struct xemac_s *)(netif->state);
 	xemacpsif_s *xemacpsif = (xemacpsif_s *)(xemac->state);

 	resetrx_on_no_rxdata(xemacpsif);
 }
	/*
	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without modification,
	* are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	* 3. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
	* OF SUCH DAMAGE.
	*
	* This file is part of the lwIP TCP/IP stack.
	*
	* Author: Adam Dunkels <adam@sics.se>
	*
	*/

	/*
	* Copyright (c) 2010-2013 Xilinx, Inc. All rights reserved.
	*
	* Xilinx, Inc.
	* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
	* COURTESY TO YOU. BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS
	* ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, APPLICATION OR
	* STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION
	* IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE
	* FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.
	* XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO
	* THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO
	* ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE
	* FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY
	* AND FITNESS FOR A PARTICULAR PURPOSE.
	*
	*/

	#include <stdio.h>
	#include <string.h>

	#include <xparameters.h>
	#include "lwipopts.h"
	#include "xlwipconfig.h"
	#include "lwip/opt.h"
	#include "lwip/def.h"
	#include "lwip/mem.h"
	#include "lwip/pbuf.h"
	#include "lwip/sys.h"
	#include "lwip/stats.h"
	#include "lwip/igmp.h"

	#include "netif/etharp.h"
	#include "netif/xemacpsif.h"
	#include "netif/xadapter.h"
	#include "netif/xpqueue.h"
	#include "xparameters.h"
	#include "xuartps.h"
	#include "xscugic.h"
	#include "xemacps.h"


	/* Define those to better describe your network interface. */
	#define IFNAME0 't'
	#define IFNAME1 'e'

	#if LWIP_IGMP
	static err_t xemacpsif_mac_filter_update (struct netif *netif,
	struct ip_addr *group, u8_t action);

	static u8_t xemacps_mcast_entry_mask = 0;
	#endif

	XEmacPs_Config *mac_config;
	struct netif *NetIf;
	void FreeTxPBufs(void);
	/*
	* this function is always called with interrupts off
	* this function also assumes that there are available BD's
	*/
	static err_t _unbuffered_low_level_output(xemacpsif_s *xemacpsif,
	struct pbuf *p)
	{
	XStatus status = 0;

	#if ETH_PAD_SIZE
	pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
	#endif
	status = emacps_sgsend(xemacpsif, p);
	if (status != XST_SUCCESS) {
	#if LINK_STATS
	lwip_stats.link.drop++;
	#endif
	}

	#if ETH_PAD_SIZE
	pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
	#endif

	#if LINK_STATS
	lwip_stats.link.xmit++;
	#endif /* LINK_STATS */

	return ERR_OK;

	}

	/*
	* low_level_output():
	*
	* Should do the actual transmission of the packet. The packet is
	* contained in the pbuf that is passed to the function. This pbuf
	* might be chained.
	*
	*/

	static err_t low_level_output(struct netif netif, struct pbuf p)
	{
	SYS_ARCH_DECL_PROTECT(lev);
	err_t err;

	struct xemac_s xemac = (struct xemac_s )(netif->state);
	xemacpsif_s xemacpsif = (xemacpsif_s )(xemac->state);

	SYS_ARCH_PROTECT(lev);


	/* check if space is available to send */
	if (is_tx_space_available(xemacpsif)) {
	_unbuffered_low_level_output(xemacpsif, p);
	err = ERR_OK;
	} else {
	#if LINK_STATS
	lwip_stats.link.drop++;
	#endif
	print("pack dropped, no space\r\n");
	err = ERR_MEM;
	}


	SYS_ARCH_UNPROTECT(lev);
	return err;
	}

	/*
	* low_level_input():
	*
	* Should allocate a pbuf and transfer the bytes of the incoming
	* packet from the interface into the pbuf.
	*
	*/
	static struct pbuf * low_level_input(struct netif *netif)
	{
	struct xemac_s xemac = (struct xemac_s )(netif->state);
	xemacpsif_s xemacpsif = (xemacpsif_s )(xemac->state);
	struct pbuf *p;

	/* see if there is data to process */
	if (pq_qlength(xemacpsif->recv_q) == 0)
	return NULL;

	/* return one packet from receive q */
	p = (struct pbuf *)pq_dequeue(xemacpsif->recv_q);
	return p;
	}

	/*
	* xemacpsif_output():
	*
	* This function is called by the TCP/IP stack when an IP packet
	* should be sent. It calls the function called low_level_output() to
	* do the actual transmission of the packet.
	*
	*/

	static err_t xemacpsif_output(struct netif netif, struct pbuf p,
	struct ip_addr *ipaddr)
	{
	/* resolve hardware address, then send (or queue) packet */
	return etharp_output(netif, p, ipaddr);
	}

	/*
	* xemacpsif_input():
	*
	* This function should be called when a packet is ready to be read
	* from the interface. It uses the function low_level_input() that
	* should handle the actual reception of bytes from the network
	* interface.
	*
	* Returns the number of packets read (max 1 packet on success,
	* 0 if there are no packets)
	*
	*/

	int xemacpsif_input(struct netif *netif)
	{
	struct eth_hdr *ethhdr;
	struct pbuf *p;
	SYS_ARCH_DECL_PROTECT(lev);

	#ifdef OS_IS_FREERTOS
	while (1)
	#endif
	{
	/* move received packet into a new pbuf */
	SYS_ARCH_PROTECT(lev);
	p = low_level_input(netif);
	SYS_ARCH_UNPROTECT(lev);

	/* no packet could be read, silently ignore this */
	if (p == NULL) {
	return 0;
	}

	/* points to packet payload, which starts with an Ethernet header */
	ethhdr = p->payload;

	#if LINK_STATS
	lwip_stats.link.recv++;
	#endif /* LINK_STATS */

	switch (htons(ethhdr->type)) {
	/* IP or ARP packet? */
	case ETHTYPE_IP:
	case ETHTYPE_ARP:
	#if PPPOE_SUPPORT
	/* PPPoE packet? */
	case ETHTYPE_PPPOEDISC:
	case ETHTYPE_PPPOE:
	#endif /* PPPOE_SUPPORT */
	/* full packet send to tcpip_thread to process */
	if (netif->input(p, netif) != ERR_OK) {
	LWIP_DEBUGF(NETIF_DEBUG, ("xemacpsif_input: IP input error\r\n"));
	pbuf_free(p);
	p = NULL;
	}
	break;

	default:
	pbuf_free(p);
	p = NULL;
	break;
	}
	}

	return 1;
	}


	static err_t low_level_init(struct netif *netif)
	{
	unsigned mac_address = (unsigned)(netif->state);
	struct xemac_s *xemac;
	xemacpsif_s *xemacpsif;
	u32 dmacrreg;

	int Status = XST_SUCCESS;

	NetIf = netif;

	xemacpsif = mem_malloc(sizeof *xemacpsif);
	if (xemacpsif == NULL) {
	LWIP_DEBUGF(NETIF_DEBUG, ("xemacpsif_init: out of memory\r\n"));
	return ERR_MEM;
	}

	xemac = mem_malloc(sizeof *xemac);
	if (xemac == NULL) {
	LWIP_DEBUGF(NETIF_DEBUG, ("xemacpsif_init: out of memory\r\n"));
	return ERR_MEM;
	}

	xemac->state = (void *)xemacpsif;
	xemac->topology_index = xtopology_find_index(mac_address);
	xemac->type = xemac_type_emacps;

	xemacpsif->send_q = NULL;
	xemacpsif->recv_q = pq_create_queue();
	if (!xemacpsif->recv_q)
	return ERR_MEM;

	/* maximum transfer unit */
	netif->mtu = XEMACPS_MTU - XEMACPS_HDR_SIZE;

	#if LWIP_IGMP
	netif->igmp_mac_filter = xemacpsif_mac_filter_update;
	#endif

	netif->flags = NETIF_FLAG_BROADCAST \| NETIF_FLAG_ETHARP \|
	NETIF_FLAG_LINK_UP;

	#if LWIP_IGMP
	netif->flags \|= NETIF_FLAG_IGMP;
	#endif

	#if !NO_SYS
	sys_sem_new(&xemac->sem_rx_data_available, 0);
	#endif
	/* obtain config of this emac */
	mac_config = (XEmacPs_Config *)xemacps_lookup_config((unsigned)netif->state);

	Status = XEmacPs_CfgInitialize(&xemacpsif->emacps, mac_config,
	mac_config->BaseAddress);
	if (Status != XST_SUCCESS) {
	xil_printf("In %s:EmacPs Configuration Failed....\r\n", __func__);
	}

	/* initialize the mac */
	init_emacps(xemacpsif, netif);

	dmacrreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_DMACR_OFFSET);
	dmacrreg = dmacrreg \| (0x00000010);
	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_DMACR_OFFSET, dmacrreg);

	setup_isr(xemac);
	init_dma(xemac);
	start_emacps(xemacpsif);

	/* replace the state in netif (currently the emac baseaddress)
	* with the mac instance pointer.
	*/
	netif->state = (void *)xemac;

	return ERR_OK;
	}

	void HandleEmacPsError(struct xemac_s *xemac)
	{
	xemacpsif_s *xemacpsif;
	int Status = XST_SUCCESS;
	u32 dmacrreg;

	SYS_ARCH_DECL_PROTECT(lev);
	SYS_ARCH_PROTECT(lev);

	FreeTxRxPBufs();
	xemacpsif = (xemacpsif_s *)(xemac->state);
	Status = XEmacPs_CfgInitialize(&xemacpsif->emacps, mac_config,
	mac_config->BaseAddress);
	if (Status != XST_SUCCESS) {
	xil_printf("In %s:EmacPs Configuration Failed....\r\n", __func__);
	}
	/* initialize the mac */
	init_emacps_on_error(xemacpsif, NetIf);
	dmacrreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_DMACR_OFFSET);
	dmacrreg = dmacrreg \| (0x01000000);
	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_DMACR_OFFSET, dmacrreg);
	setup_isr(xemac);
	init_dma(xemac);
	start_emacps(xemacpsif);

	SYS_ARCH_UNPROTECT(lev);
	}

	void HandleTxErrors(struct xemac_s *xemac)
	{
	xemacpsif_s *xemacpsif;
	u32 netctrlreg;

	SYS_ARCH_DECL_PROTECT(lev);
	SYS_ARCH_PROTECT(lev);
	xemacpsif = (xemacpsif_s *)(xemac->state);
	netctrlreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_NWCTRL_OFFSET);
	netctrlreg = netctrlreg & (~XEMACPS_NWCTRL_TXEN_MASK);
	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_NWCTRL_OFFSET, netctrlreg);
	FreeOnlyTxPBufs();

	clean_dma_txdescs(xemac);
	netctrlreg = XEmacPs_ReadReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_NWCTRL_OFFSET);
	netctrlreg = netctrlreg \| (XEMACPS_NWCTRL_TXEN_MASK);
	XEmacPs_WriteReg(xemacpsif->emacps.Config.BaseAddress,
	XEMACPS_NWCTRL_OFFSET, netctrlreg);
	SYS_ARCH_UNPROTECT(lev);
	}


	#if LWIP_IGMP
	static err_t xemacpsif_mac_filter_update (struct netif netif, struct ip_addr group,
	u8_t action)
	{
	return 0;
	}
	#endif

	/*
	* xemacpsif_init():
	*
	* Should be called at the beginning of the program to set up the
	* network interface. It calls the function low_level_init() to do the
	* actual setup of the hardware.
	*
	*/

	err_t xemacpsif_init(struct netif *netif)
	{
	#if LWIP_SNMP
	/* ifType ethernetCsmacd(6) @see RFC1213 */
	netif->link_type = 6;
	/* your link speed here */
	netif->link_speed = ;
	netif->ts = 0;
	netif->ifinoctets = 0;
	netif->ifinucastpkts = 0;
	netif->ifinnucastpkts = 0;
	netif->ifindiscards = 0;
	netif->ifoutoctets = 0;
	netif->ifoutucastpkts = 0;
	netif->ifoutnucastpkts = 0;
	netif->ifoutdiscards = 0;
	#endif

	netif->name[0] = IFNAME0;
	netif->name[1] = IFNAME1;
	netif->output = xemacpsif_output;
	netif->linkoutput = low_level_output;

	low_level_init(netif);
	return ERR_OK;
	}

	/*
	* xemacpsif_resetrx_on_no_rxdata():
	*
	* Should be called by the user at regular intervals, typically
	* from a timer (100 msecond). This is to provide a SW workaround
	* for the HW bug (SI #692601). Please refer to the function header
	* for the function resetrx_on_no_rxdata in xemacpsif_dma.c to
	* know more about the SI.
	*
	*/

	void xemacpsif_resetrx_on_no_rxdata(struct netif *netif)
	{
	struct xemac_s xemac = (struct xemac_s )(netif->state);
	xemacpsif_s xemacpsif = (xemacpsif_s )(xemac->state);

	resetrx_on_no_rxdata(xemacpsif);
	}