summaryrefslogblamecommitdiffstats
path: root/drivers/net/ixgb/ixgb_main.c
blob: 0de3ed08ff56eff08f788e8c46cf912cc27ca47d (plain) (tree)
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037






























                                                                                




                                                                        










                                                                                   
                                                                       





                          
                                                      
                                         
                                                                            











                                                      

                                                     









































                                                                             
 
















                                                                           




                                                 




                                                             
                                     
                                 

                                             




                                                           
                            

                                                            
                                                                                   




                                                                                  










                                                                  




                                                        
                                             













                                                               




























                                                                 

                                                                                











































































































































                                                                                        

                                                                        

                                  

                                                                               
                                                                            
                                          




                                                               
                                         












                                                             
                                      































































                                                                          


                                         












                                                                      
                                                                      
 
                                                     






































                                                                       


                                 
















                                                                    
                                                           




































                                                                              


                                                           






























                                                                     
                                                           









































                                                                    
                                                           





































































































































































































































































































































































































                                                                              
                                                           
























                                                                     
                                                           





















































































































































                                                                                 


                                                                           
 

































                                                                              
                                                            




















                                                              
                                                     


                                                          
 






                                                           




                                                                         























                                                                   





                                                                               












































































                                                                                

                                                      



                                                               
                                                           










                                       







                                                             
                                                    

      


                                                                         
                                      
         

                    
                                                         
      










                                                        


                                                                 


                                    
                        








                                                                         








                                                                       









                                              
                                                           







                                                       
                                                           















                                                               
                                                           














                                                       
                                                           










































                                                                                










                                                                             

                                       










                                                                           



                                                                   






































































                                                                        





























                                                                     
                                                           













































                                                                       
                                                           









































































































































                                                                                








                                                         

                                               






                                            
                                         
                                       
 













                                                        








                                                      
                                                                   






                                                                            
                                         







                                                                               
                                         









                                                            
                                                                         






                                                                        
                                                                         








                                                                        

                                                                      


                                        
                                           


































                                                           

                                            

























                                                                           



                                                                          


























                                                                             
                                                           




































                                                             
                                                           












                                                              
                                                           































                                                                   









                                                                    
 






                                                 
/*******************************************************************************

  
  Copyright(c) 1999 - 2005 Intel Corporation. All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it 
  under the terms of the GNU General Public License as published by the Free 
  Software Foundation; either version 2 of the License, or (at your option) 
  any later version.
  
  This program is distributed in the hope that it will be useful, but WITHOUT 
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for 
  more details.
  
  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc., 59 
  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  
  The full GNU General Public License is included in this distribution in the
  file called LICENSE.
  
  Contact Information:
  Linux NICS <linux.nics@intel.com>
  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

*******************************************************************************/

#include "ixgb.h"

/* Change Log
 * 1.0.96 04/19/05
 * - Make needlessly global code static -- bunk@stusta.de
 * - ethtool cleanup -- shemminger@osdl.org
 * - Support for MODULE_VERSION -- linville@tuxdriver.com
 * - add skb_header_cloned check to the tso path -- herbert@apana.org.au
 * 1.0.88 01/05/05
 * - include fix to the condition that determines when to quit NAPI - Robert Olsson
 * - use netif_poll_{disable/enable} to synchronize between NAPI and i/f up/down
 * 1.0.84 10/26/04
 * - reset buffer_info->dma in Tx resource cleanup logic
 * 1.0.83 10/12/04
 * - sparse cleanup - shemminger@osdl.org
 * - fix tx resource cleanup logic
 */

char ixgb_driver_name[] = "ixgb";
static char ixgb_driver_string[] = "Intel(R) PRO/10GbE Network Driver";

#ifndef CONFIG_IXGB_NAPI
#define DRIVERNAPI
#else
#define DRIVERNAPI "-NAPI"
#endif
#define DRV_VERSION		"1.0.100-k2"DRIVERNAPI
char ixgb_driver_version[] = DRV_VERSION;
static char ixgb_copyright[] = "Copyright (c) 1999-2005 Intel Corporation.";

/* ixgb_pci_tbl - PCI Device ID Table
 *
 * Wildcard entries (PCI_ANY_ID) should come last
 * Last entry must be all 0s
 *
 * { Vendor ID, Device ID, SubVendor ID, SubDevice ID,
 *   Class, Class Mask, private data (not used) }
 */
static struct pci_device_id ixgb_pci_tbl[] = {
	{INTEL_VENDOR_ID, IXGB_DEVICE_ID_82597EX,
	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
	{INTEL_VENDOR_ID, IXGB_DEVICE_ID_82597EX_CX4,
	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
	{INTEL_VENDOR_ID, IXGB_DEVICE_ID_82597EX_SR,
	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
	{INTEL_VENDOR_ID, IXGB_DEVICE_ID_82597EX_LR,  
	 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},

	/* required last entry */
	{0,}
};

MODULE_DEVICE_TABLE(pci, ixgb_pci_tbl);

/* Local Function Prototypes */

int ixgb_up(struct ixgb_adapter *adapter);
void ixgb_down(struct ixgb_adapter *adapter, boolean_t kill_watchdog);
void ixgb_reset(struct ixgb_adapter *adapter);
int ixgb_setup_tx_resources(struct ixgb_adapter *adapter);
int ixgb_setup_rx_resources(struct ixgb_adapter *adapter);
void ixgb_free_tx_resources(struct ixgb_adapter *adapter);
void ixgb_free_rx_resources(struct ixgb_adapter *adapter);
void ixgb_update_stats(struct ixgb_adapter *adapter);

static int ixgb_init_module(void);
static void ixgb_exit_module(void);
static int ixgb_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
static void __devexit ixgb_remove(struct pci_dev *pdev);
static int ixgb_sw_init(struct ixgb_adapter *adapter);
static int ixgb_open(struct net_device *netdev);
static int ixgb_close(struct net_device *netdev);
static void ixgb_configure_tx(struct ixgb_adapter *adapter);
static void ixgb_configure_rx(struct ixgb_adapter *adapter);
static void ixgb_setup_rctl(struct ixgb_adapter *adapter);
static void ixgb_clean_tx_ring(struct ixgb_adapter *adapter);
static void ixgb_clean_rx_ring(struct ixgb_adapter *adapter);
static void ixgb_set_multi(struct net_device *netdev);
static void ixgb_watchdog(unsigned long data);
static int ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev);
static struct net_device_stats *ixgb_get_stats(struct net_device *netdev);
static int ixgb_change_mtu(struct net_device *netdev, int new_mtu);
static int ixgb_set_mac(struct net_device *netdev, void *p);
static irqreturn_t ixgb_intr(int irq, void *data, struct pt_regs *regs);
static boolean_t ixgb_clean_tx_irq(struct ixgb_adapter *adapter);

#ifdef CONFIG_IXGB_NAPI
static int ixgb_clean(struct net_device *netdev, int *budget);
static boolean_t ixgb_clean_rx_irq(struct ixgb_adapter *adapter,
				   int *work_done, int work_to_do);
#else
static boolean_t ixgb_clean_rx_irq(struct ixgb_adapter *adapter);
#endif
static void ixgb_alloc_rx_buffers(struct ixgb_adapter *adapter);
void ixgb_set_ethtool_ops(struct net_device *netdev);
static void ixgb_tx_timeout(struct net_device *dev);
static void ixgb_tx_timeout_task(struct net_device *dev);
static void ixgb_vlan_rx_register(struct net_device *netdev,
				  struct vlan_group *grp);
static void ixgb_vlan_rx_add_vid(struct net_device *netdev, uint16_t vid);
static void ixgb_vlan_rx_kill_vid(struct net_device *netdev, uint16_t vid);
static void ixgb_restore_vlan(struct ixgb_adapter *adapter);

#ifdef CONFIG_NET_POLL_CONTROLLER
/* for netdump / net console */
static void ixgb_netpoll(struct net_device *dev);
#endif

/* Exported from other modules */

extern void ixgb_check_options(struct ixgb_adapter *adapter);

static struct pci_driver ixgb_driver = {
	.name     = ixgb_driver_name,
	.id_table = ixgb_pci_tbl,
	.probe    = ixgb_probe,
	.remove   = __devexit_p(ixgb_remove),
};

MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
MODULE_DESCRIPTION("Intel(R) PRO/10GbE Network Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

/* some defines for controlling descriptor fetches in h/w */
#define RXDCTL_WTHRESH_DEFAULT 16	/* chip writes back at this many or RXT0 */
#define RXDCTL_PTHRESH_DEFAULT 0		/* chip considers prefech below
						 * this */
#define RXDCTL_HTHRESH_DEFAULT 0		/* chip will only prefetch if tail
						 * is pushed this many descriptors
						 * from head */

/**
 * ixgb_init_module - Driver Registration Routine
 *
 * ixgb_init_module is the first routine called when the driver is
 * loaded. All it does is register with the PCI subsystem.
 **/

static int __init
ixgb_init_module(void)
{
	printk(KERN_INFO "%s - version %s\n",
	       ixgb_driver_string, ixgb_driver_version);

	printk(KERN_INFO "%s\n", ixgb_copyright);

	return pci_module_init(&ixgb_driver);
}

module_init(ixgb_init_module);

/**
 * ixgb_exit_module - Driver Exit Cleanup Routine
 *
 * ixgb_exit_module is called just before the driver is removed
 * from memory.
 **/

static void __exit
ixgb_exit_module(void)
{
	pci_unregister_driver(&ixgb_driver);
}

module_exit(ixgb_exit_module);

/**
 * ixgb_irq_disable - Mask off interrupt generation on the NIC
 * @adapter: board private structure
 **/

static inline void
ixgb_irq_disable(struct ixgb_adapter *adapter)
{
	atomic_inc(&adapter->irq_sem);
	IXGB_WRITE_REG(&adapter->hw, IMC, ~0);
	IXGB_WRITE_FLUSH(&adapter->hw);
	synchronize_irq(adapter->pdev->irq);
}

/**
 * ixgb_irq_enable - Enable default interrupt generation settings
 * @adapter: board private structure
 **/

static inline void
ixgb_irq_enable(struct ixgb_adapter *adapter)
{
	if(atomic_dec_and_test(&adapter->irq_sem)) {
		IXGB_WRITE_REG(&adapter->hw, IMS,
			       IXGB_INT_RXT0 | IXGB_INT_RXDMT0 | IXGB_INT_TXDW |
			       IXGB_INT_LSC);
		IXGB_WRITE_FLUSH(&adapter->hw);
	}
}

int
ixgb_up(struct ixgb_adapter *adapter)
{
	struct net_device *netdev = adapter->netdev;
	int err;
	int max_frame = netdev->mtu + ENET_HEADER_SIZE + ENET_FCS_LENGTH;
	struct ixgb_hw *hw = &adapter->hw;

	/* hardware has been reset, we need to reload some things */

	ixgb_set_multi(netdev);

	ixgb_restore_vlan(adapter);

	ixgb_configure_tx(adapter);
	ixgb_setup_rctl(adapter);
	ixgb_configure_rx(adapter);
	ixgb_alloc_rx_buffers(adapter);

#ifdef CONFIG_PCI_MSI
	{
	boolean_t pcix = (IXGB_READ_REG(&adapter->hw, STATUS) & 
						  IXGB_STATUS_PCIX_MODE) ? TRUE : FALSE;
	adapter->have_msi = TRUE;

	if (!pcix)
	   adapter->have_msi = FALSE;
	else if((err = pci_enable_msi(adapter->pdev))) {
		printk (KERN_ERR
		 "Unable to allocate MSI interrupt Error: %d\n", err);
		adapter->have_msi = FALSE;
		/* proceed to try to request regular interrupt */
	}
	}

#endif
	if((err = request_irq(adapter->pdev->irq, &ixgb_intr,
				  SA_SHIRQ | SA_SAMPLE_RANDOM,
				  netdev->name, netdev)))
		return err;

	/* disable interrupts and get the hardware into a known state */
	IXGB_WRITE_REG(&adapter->hw, IMC, 0xffffffff);

	if((hw->max_frame_size != max_frame) ||
		(hw->max_frame_size !=
		(IXGB_READ_REG(hw, MFS) >> IXGB_MFS_SHIFT))) {

		hw->max_frame_size = max_frame;

		IXGB_WRITE_REG(hw, MFS, hw->max_frame_size << IXGB_MFS_SHIFT);

		if(hw->max_frame_size >
		   IXGB_MAX_ENET_FRAME_SIZE_WITHOUT_FCS + ENET_FCS_LENGTH) {
			uint32_t ctrl0 = IXGB_READ_REG(hw, CTRL0);

			if(!(ctrl0 & IXGB_CTRL0_JFE)) {
				ctrl0 |= IXGB_CTRL0_JFE;
				IXGB_WRITE_REG(hw, CTRL0, ctrl0);
			}
		}
	}

	mod_timer(&adapter->watchdog_timer, jiffies);
	ixgb_irq_enable(adapter);

#ifdef CONFIG_IXGB_NAPI
	netif_poll_enable(netdev);
#endif
	return 0;
}

void
ixgb_down(struct ixgb_adapter *adapter, boolean_t kill_watchdog)
{
	struct net_device *netdev = adapter->netdev;

	ixgb_irq_disable(adapter);
	free_irq(adapter->pdev->irq, netdev);
#ifdef CONFIG_PCI_MSI
	if(adapter->have_msi == TRUE)
		pci_disable_msi(adapter->pdev);

#endif
	if(kill_watchdog)
		del_timer_sync(&adapter->watchdog_timer);
#ifdef CONFIG_IXGB_NAPI
	netif_poll_disable(netdev);
#endif
	adapter->link_speed = 0;
	adapter->link_duplex = 0;
	netif_carrier_off(netdev);
	netif_stop_queue(netdev);

	ixgb_reset(adapter);
	ixgb_clean_tx_ring(adapter);
	ixgb_clean_rx_ring(adapter);
}

void
ixgb_reset(struct ixgb_adapter *adapter)
{

	ixgb_adapter_stop(&adapter->hw);
	if(!ixgb_init_hw(&adapter->hw))
		IXGB_DBG("ixgb_init_hw failed.\n");
}

/**
 * ixgb_probe - Device Initialization Routine
 * @pdev: PCI device information struct
 * @ent: entry in ixgb_pci_tbl
 *
 * Returns 0 on success, negative on failure
 *
 * ixgb_probe initializes an adapter identified by a pci_dev structure.
 * The OS initialization, configuring of the adapter private structure,
 * and a hardware reset occur.
 **/

static int __devinit
ixgb_probe(struct pci_dev *pdev,
		const struct pci_device_id *ent)
{
	struct net_device *netdev = NULL;
	struct ixgb_adapter *adapter;
	static int cards_found = 0;
	unsigned long mmio_start;
	int mmio_len;
	int pci_using_dac;
	int i;
	int err;

	if((err = pci_enable_device(pdev)))
		return err;

	if(!(err = pci_set_dma_mask(pdev, DMA_64BIT_MASK)) &&
	   !(err = pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK))) {
		pci_using_dac = 1;
	} else {
		if((err = pci_set_dma_mask(pdev, DMA_32BIT_MASK)) ||
		   (err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK))) {
			IXGB_ERR("No usable DMA configuration, aborting\n");
			goto err_dma_mask;
		}
		pci_using_dac = 0;
	}

	if((err = pci_request_regions(pdev, ixgb_driver_name)))
		goto err_request_regions;

	pci_set_master(pdev);

	netdev = alloc_etherdev(sizeof(struct ixgb_adapter));
	if(!netdev) {
		err = -ENOMEM;
		goto err_alloc_etherdev;
	}

	SET_MODULE_OWNER(netdev);
	SET_NETDEV_DEV(netdev, &pdev->dev);

	pci_set_drvdata(pdev, netdev);
	adapter = netdev_priv(netdev);
	adapter->netdev = netdev;
	adapter->pdev = pdev;
	adapter->hw.back = adapter;

	mmio_start = pci_resource_start(pdev, BAR_0);
	mmio_len = pci_resource_len(pdev, BAR_0);

	adapter->hw.hw_addr = ioremap(mmio_start, mmio_len);
	if(!adapter->hw.hw_addr) {
		err = -EIO;
		goto err_ioremap;
	}

	for(i = BAR_1; i <= BAR_5; i++) {
		if(pci_resource_len(pdev, i) == 0)
			continue;
		if(pci_resource_flags(pdev, i) & IORESOURCE_IO) {
			adapter->hw.io_base = pci_resource_start(pdev, i);
			break;
		}
	}

	netdev->open = &ixgb_open;
	netdev->stop = &ixgb_close;
	netdev->hard_start_xmit = &ixgb_xmit_frame;
	netdev->get_stats = &ixgb_get_stats;
	netdev->set_multicast_list = &ixgb_set_multi;
	netdev->set_mac_address = &ixgb_set_mac;
	netdev->change_mtu = &ixgb_change_mtu;
	ixgb_set_ethtool_ops(netdev);
	netdev->tx_timeout = &ixgb_tx_timeout;
	netdev->watchdog_timeo = HZ;
#ifdef CONFIG_IXGB_NAPI
	netdev->poll = &ixgb_clean;
	netdev->weight = 64;
#endif
	netdev->vlan_rx_register = ixgb_vlan_rx_register;
	netdev->vlan_rx_add_vid = ixgb_vlan_rx_add_vid;
	netdev->vlan_rx_kill_vid = ixgb_vlan_rx_kill_vid;
#ifdef CONFIG_NET_POLL_CONTROLLER
	netdev->poll_controller = ixgb_netpoll;
#endif

	netdev->mem_start = mmio_start;
	netdev->mem_end = mmio_start + mmio_len;
	netdev->base_addr = adapter->hw.io_base;

	adapter->bd_number = cards_found;
	adapter->link_speed = 0;
	adapter->link_duplex = 0;

	/* setup the private structure */

	if((err = ixgb_sw_init(adapter)))
		goto err_sw_init;

	netdev->features = NETIF_F_SG |
			   NETIF_F_HW_CSUM |
			   NETIF_F_HW_VLAN_TX |
			   NETIF_F_HW_VLAN_RX |
			   NETIF_F_HW_VLAN_FILTER;
#ifdef NETIF_F_TSO
	netdev->features |= NETIF_F_TSO;
#endif
#ifdef NETIF_F_LLTX
	netdev->features |= NETIF_F_LLTX;
#endif

	if(pci_using_dac)
		netdev->features |= NETIF_F_HIGHDMA;

	/* make sure the EEPROM is good */

	if(!ixgb_validate_eeprom_checksum(&adapter->hw)) {
		printk(KERN_ERR "The EEPROM Checksum Is Not Valid\n");
		err = -EIO;
		goto err_eeprom;
	}

	ixgb_get_ee_mac_addr(&adapter->hw, netdev->dev_addr);
	memcpy(netdev->perm_addr, netdev->dev_addr, netdev->addr_len);

	if(!is_valid_ether_addr(netdev->perm_addr)) {
		err = -EIO;
		goto err_eeprom;
	}

	adapter->part_num = ixgb_get_ee_pba_number(&adapter->hw);

	init_timer(&adapter->watchdog_timer);
	adapter->watchdog_timer.function = &ixgb_watchdog;
	adapter->watchdog_timer.data = (unsigned long)adapter;

	INIT_WORK(&adapter->tx_timeout_task,
		  (void (*)(void *))ixgb_tx_timeout_task, netdev);

	if((err = register_netdev(netdev)))
		goto err_register;

	/* we're going to reset, so assume we have no link for now */

	netif_carrier_off(netdev);
	netif_stop_queue(netdev);

	printk(KERN_INFO "%s: Intel(R) PRO/10GbE Network Connection\n",
		   netdev->name);
	ixgb_check_options(adapter);
	/* reset the hardware with the new settings */

	ixgb_reset(adapter);

	cards_found++;
	return 0;

err_register:
err_sw_init:
err_eeprom:
	iounmap(adapter->hw.hw_addr);
err_ioremap:
	free_netdev(netdev);
err_alloc_etherdev:
	pci_release_regions(pdev);
err_request_regions:
err_dma_mask:
	pci_disable_device(pdev);
	return err;
}

/**
 * ixgb_remove - Device Removal Routine
 * @pdev: PCI device information struct
 *
 * ixgb_remove is called by the PCI subsystem to alert the driver
 * that it should release a PCI device.  The could be caused by a
 * Hot-Plug event, or because the driver is going to be removed from
 * memory.
 **/

static void __devexit
ixgb_remove(struct pci_dev *pdev)
{
	struct net_device *netdev = pci_get_drvdata(pdev);
	struct ixgb_adapter *adapter = netdev_priv(netdev);

	unregister_netdev(netdev);

	iounmap(adapter->hw.hw_addr);
	pci_release_regions(pdev);

	free_netdev(netdev);
}

/**
 * ixgb_sw_init - Initialize general software structures (struct ixgb_adapter)
 * @adapter: board private structure to initialize
 *
 * ixgb_sw_init initializes the Adapter private data structure.
 * Fields are initialized based on PCI device information and
 * OS network device settings (MTU size).
 **/

static int __devinit
ixgb_sw_init(struct ixgb_adapter *adapter)
{
	struct ixgb_hw *hw = &adapter->hw;
	struct net_device *netdev = adapter->netdev;
	struct pci_dev *pdev = adapter->pdev;

	/* PCI config space info */

	hw->vendor_id = pdev->vendor;
	hw->device_id = pdev->device;
	hw->subsystem_vendor_id = pdev->subsystem_vendor;
	hw->subsystem_id = pdev->subsystem_device;

	adapter->rx_buffer_len = IXGB_RXBUFFER_2048;

	hw->max_frame_size = netdev->mtu + ENET_HEADER_SIZE + ENET_FCS_LENGTH;

	if((hw->device_id == IXGB_DEVICE_ID_82597EX)
	   || (hw->device_id == IXGB_DEVICE_ID_82597EX_CX4)
	   || (hw->device_id == IXGB_DEVICE_ID_82597EX_LR)
	   || (hw->device_id == IXGB_DEVICE_ID_82597EX_SR))
			hw->mac_type = ixgb_82597;
	else {
		/* should never have loaded on this device */
		printk(KERN_ERR "ixgb: unsupported device id\n");
	}

	/* enable flow control to be programmed */
	hw->fc.send_xon = 1;

	atomic_set(&adapter->irq_sem, 1);
	spin_lock_init(&adapter->tx_lock);

	return 0;
}

/**
 * ixgb_open - Called when a network interface is made active
 * @netdev: network interface device structure
 *
 * Returns 0 on success, negative value on failure
 *
 * The open entry point is called when a network interface is made
 * active by the system (IFF_UP).  At this point all resources needed
 * for transmit and receive operations are allocated, the interrupt
 * handler is registered with the OS, the watchdog timer is started,
 * and the stack is notified that the interface is ready.
 **/

static int
ixgb_open(struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	int err;

	/* allocate transmit descriptors */

	if((err = ixgb_setup_tx_resources(adapter)))
		goto err_setup_tx;

	/* allocate receive descriptors */

	if((err = ixgb_setup_rx_resources(adapter)))
		goto err_setup_rx;

	if((err = ixgb_up(adapter)))
		goto err_up;

	return 0;

err_up:
	ixgb_free_rx_resources(adapter);
err_setup_rx:
	ixgb_free_tx_resources(adapter);
err_setup_tx:
	ixgb_reset(adapter);

	return err;
}

/**
 * ixgb_close - Disables a network interface
 * @netdev: network interface device structure
 *
 * Returns 0, this is not allowed to fail
 *
 * The close entry point is called when an interface is de-activated
 * by the OS.  The hardware is still under the drivers control, but
 * needs to be disabled.  A global MAC reset is issued to stop the
 * hardware, and all transmit and receive resources are freed.
 **/

static int
ixgb_close(struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);

	ixgb_down(adapter, TRUE);

	ixgb_free_tx_resources(adapter);
	ixgb_free_rx_resources(adapter);

	return 0;
}

/**
 * ixgb_setup_tx_resources - allocate Tx resources (Descriptors)
 * @adapter: board private structure
 *
 * Return 0 on success, negative on failure
 **/

int
ixgb_setup_tx_resources(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *txdr = &adapter->tx_ring;
	struct pci_dev *pdev = adapter->pdev;
	int size;

	size = sizeof(struct ixgb_buffer) * txdr->count;
	txdr->buffer_info = vmalloc(size);
	if(!txdr->buffer_info) {
		return -ENOMEM;
	}
	memset(txdr->buffer_info, 0, size);

	/* round up to nearest 4K */

	txdr->size = txdr->count * sizeof(struct ixgb_tx_desc);
	IXGB_ROUNDUP(txdr->size, 4096);

	txdr->desc = pci_alloc_consistent(pdev, txdr->size, &txdr->dma);
	if(!txdr->desc) {
		vfree(txdr->buffer_info);
		return -ENOMEM;
	}
	memset(txdr->desc, 0, txdr->size);

	txdr->next_to_use = 0;
	txdr->next_to_clean = 0;

	return 0;
}

/**
 * ixgb_configure_tx - Configure 82597 Transmit Unit after Reset.
 * @adapter: board private structure
 *
 * Configure the Tx unit of the MAC after a reset.
 **/

static void
ixgb_configure_tx(struct ixgb_adapter *adapter)
{
	uint64_t tdba = adapter->tx_ring.dma;
	uint32_t tdlen = adapter->tx_ring.count * sizeof(struct ixgb_tx_desc);
	uint32_t tctl;
	struct ixgb_hw *hw = &adapter->hw;

	/* Setup the Base and Length of the Tx Descriptor Ring 
	 * tx_ring.dma can be either a 32 or 64 bit value 
	 */

	IXGB_WRITE_REG(hw, TDBAL, (tdba & 0x00000000ffffffffULL));
	IXGB_WRITE_REG(hw, TDBAH, (tdba >> 32));

	IXGB_WRITE_REG(hw, TDLEN, tdlen);

	/* Setup the HW Tx Head and Tail descriptor pointers */

	IXGB_WRITE_REG(hw, TDH, 0);
	IXGB_WRITE_REG(hw, TDT, 0);

	/* don't set up txdctl, it induces performance problems if configured
	 * incorrectly */
	/* Set the Tx Interrupt Delay register */

	IXGB_WRITE_REG(hw, TIDV, adapter->tx_int_delay);

	/* Program the Transmit Control Register */

	tctl = IXGB_TCTL_TCE | IXGB_TCTL_TXEN | IXGB_TCTL_TPDE;
	IXGB_WRITE_REG(hw, TCTL, tctl);

	/* Setup Transmit Descriptor Settings for this adapter */
	adapter->tx_cmd_type =
		IXGB_TX_DESC_TYPE 
		| (adapter->tx_int_delay_enable ? IXGB_TX_DESC_CMD_IDE : 0);
}

/**
 * ixgb_setup_rx_resources - allocate Rx resources (Descriptors)
 * @adapter: board private structure
 *
 * Returns 0 on success, negative on failure
 **/

int
ixgb_setup_rx_resources(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *rxdr = &adapter->rx_ring;
	struct pci_dev *pdev = adapter->pdev;
	int size;

	size = sizeof(struct ixgb_buffer) * rxdr->count;
	rxdr->buffer_info = vmalloc(size);
	if(!rxdr->buffer_info) {
		return -ENOMEM;
	}
	memset(rxdr->buffer_info, 0, size);

	/* Round up to nearest 4K */

	rxdr->size = rxdr->count * sizeof(struct ixgb_rx_desc);
	IXGB_ROUNDUP(rxdr->size, 4096);

	rxdr->desc = pci_alloc_consistent(pdev, rxdr->size, &rxdr->dma);

	if(!rxdr->desc) {
		vfree(rxdr->buffer_info);
		return -ENOMEM;
	}
	memset(rxdr->desc, 0, rxdr->size);

	rxdr->next_to_clean = 0;
	rxdr->next_to_use = 0;

	return 0;
}

/**
 * ixgb_setup_rctl - configure the receive control register
 * @adapter: Board private structure
 **/

static void
ixgb_setup_rctl(struct ixgb_adapter *adapter)
{
	uint32_t rctl;

	rctl = IXGB_READ_REG(&adapter->hw, RCTL);

	rctl &= ~(3 << IXGB_RCTL_MO_SHIFT);

	rctl |=
		IXGB_RCTL_BAM | IXGB_RCTL_RDMTS_1_2 | 
		IXGB_RCTL_RXEN | IXGB_RCTL_CFF | 
		(adapter->hw.mc_filter_type << IXGB_RCTL_MO_SHIFT);

	rctl |= IXGB_RCTL_SECRC;

	switch (adapter->rx_buffer_len) {
	case IXGB_RXBUFFER_2048:
	default:
		rctl |= IXGB_RCTL_BSIZE_2048;
		break;
	case IXGB_RXBUFFER_4096:
		rctl |= IXGB_RCTL_BSIZE_4096;
		break;
	case IXGB_RXBUFFER_8192:
		rctl |= IXGB_RCTL_BSIZE_8192;
		break;
	case IXGB_RXBUFFER_16384:
		rctl |= IXGB_RCTL_BSIZE_16384;
		break;
	}

	IXGB_WRITE_REG(&adapter->hw, RCTL, rctl);
}

/**
 * ixgb_configure_rx - Configure 82597 Receive Unit after Reset.
 * @adapter: board private structure
 *
 * Configure the Rx unit of the MAC after a reset.
 **/

static void
ixgb_configure_rx(struct ixgb_adapter *adapter)
{
	uint64_t rdba = adapter->rx_ring.dma;
	uint32_t rdlen = adapter->rx_ring.count * sizeof(struct ixgb_rx_desc);
	struct ixgb_hw *hw = &adapter->hw;
	uint32_t rctl;
	uint32_t rxcsum;
	uint32_t rxdctl;

	/* make sure receives are disabled while setting up the descriptors */

	rctl = IXGB_READ_REG(hw, RCTL);
	IXGB_WRITE_REG(hw, RCTL, rctl & ~IXGB_RCTL_RXEN);

	/* set the Receive Delay Timer Register */

	IXGB_WRITE_REG(hw, RDTR, adapter->rx_int_delay);

	/* Setup the Base and Length of the Rx Descriptor Ring */

	IXGB_WRITE_REG(hw, RDBAL, (rdba & 0x00000000ffffffffULL));
	IXGB_WRITE_REG(hw, RDBAH, (rdba >> 32));

	IXGB_WRITE_REG(hw, RDLEN, rdlen);

	/* Setup the HW Rx Head and Tail Descriptor Pointers */
	IXGB_WRITE_REG(hw, RDH, 0);
	IXGB_WRITE_REG(hw, RDT, 0);

	/* set up pre-fetching of receive buffers so we get some before we
	 * run out (default hardware behavior is to run out before fetching
	 * more).  This sets up to fetch if HTHRESH rx descriptors are avail
	 * and the descriptors in hw cache are below PTHRESH.  This avoids
	 * the hardware behavior of fetching <=512 descriptors in a single
	 * burst that pre-empts all other activity, usually causing fifo
	 * overflows. */
	/* use WTHRESH to burst write 16 descriptors or burst when RXT0 */
	rxdctl = RXDCTL_WTHRESH_DEFAULT << IXGB_RXDCTL_WTHRESH_SHIFT |
	         RXDCTL_HTHRESH_DEFAULT << IXGB_RXDCTL_HTHRESH_SHIFT |
	         RXDCTL_PTHRESH_DEFAULT << IXGB_RXDCTL_PTHRESH_SHIFT;
	IXGB_WRITE_REG(hw, RXDCTL, rxdctl);

	/* Enable Receive Checksum Offload for TCP and UDP */
	if(adapter->rx_csum == TRUE) {
		rxcsum = IXGB_READ_REG(hw, RXCSUM);
		rxcsum |= IXGB_RXCSUM_TUOFL;
		IXGB_WRITE_REG(hw, RXCSUM, rxcsum);
	}

	/* Enable Receives */

	IXGB_WRITE_REG(hw, RCTL, rctl);
}

/**
 * ixgb_free_tx_resources - Free Tx Resources
 * @adapter: board private structure
 *
 * Free all transmit software resources
 **/

void
ixgb_free_tx_resources(struct ixgb_adapter *adapter)
{
	struct pci_dev *pdev = adapter->pdev;

	ixgb_clean_tx_ring(adapter);

	vfree(adapter->tx_ring.buffer_info);
	adapter->tx_ring.buffer_info = NULL;

	pci_free_consistent(pdev, adapter->tx_ring.size,
			    adapter->tx_ring.desc, adapter->tx_ring.dma);

	adapter->tx_ring.desc = NULL;
}

static inline void
ixgb_unmap_and_free_tx_resource(struct ixgb_adapter *adapter,
					struct ixgb_buffer *buffer_info)
{
	struct pci_dev *pdev = adapter->pdev;
	if(buffer_info->dma) {
		pci_unmap_page(pdev,
			   buffer_info->dma,
			   buffer_info->length,
			   PCI_DMA_TODEVICE);
		buffer_info->dma = 0;
	}
	if(buffer_info->skb) {
		dev_kfree_skb_any(buffer_info->skb);
		buffer_info->skb = NULL;
	}
}

/**
 * ixgb_clean_tx_ring - Free Tx Buffers
 * @adapter: board private structure
 **/

static void
ixgb_clean_tx_ring(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *tx_ring = &adapter->tx_ring;
	struct ixgb_buffer *buffer_info;
	unsigned long size;
	unsigned int i;

	/* Free all the Tx ring sk_buffs */

	for(i = 0; i < tx_ring->count; i++) {
		buffer_info = &tx_ring->buffer_info[i];
		ixgb_unmap_and_free_tx_resource(adapter, buffer_info);
	}

	size = sizeof(struct ixgb_buffer) * tx_ring->count;
	memset(tx_ring->buffer_info, 0, size);

	/* Zero out the descriptor ring */

	memset(tx_ring->desc, 0, tx_ring->size);

	tx_ring->next_to_use = 0;
	tx_ring->next_to_clean = 0;

	IXGB_WRITE_REG(&adapter->hw, TDH, 0);
	IXGB_WRITE_REG(&adapter->hw, TDT, 0);
}

/**
 * ixgb_free_rx_resources - Free Rx Resources
 * @adapter: board private structure
 *
 * Free all receive software resources
 **/

void
ixgb_free_rx_resources(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *rx_ring = &adapter->rx_ring;
	struct pci_dev *pdev = adapter->pdev;

	ixgb_clean_rx_ring(adapter);

	vfree(rx_ring->buffer_info);
	rx_ring->buffer_info = NULL;

	pci_free_consistent(pdev, rx_ring->size, rx_ring->desc, rx_ring->dma);

	rx_ring->desc = NULL;
}

/**
 * ixgb_clean_rx_ring - Free Rx Buffers
 * @adapter: board private structure
 **/

static void
ixgb_clean_rx_ring(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *rx_ring = &adapter->rx_ring;
	struct ixgb_buffer *buffer_info;
	struct pci_dev *pdev = adapter->pdev;
	unsigned long size;
	unsigned int i;

	/* Free all the Rx ring sk_buffs */

	for(i = 0; i < rx_ring->count; i++) {
		buffer_info = &rx_ring->buffer_info[i];
		if(buffer_info->skb) {

			pci_unmap_single(pdev,
					 buffer_info->dma,
					 buffer_info->length,
					 PCI_DMA_FROMDEVICE);

			dev_kfree_skb(buffer_info->skb);

			buffer_info->skb = NULL;
		}
	}

	size = sizeof(struct ixgb_buffer) * rx_ring->count;
	memset(rx_ring->buffer_info, 0, size);

	/* Zero out the descriptor ring */

	memset(rx_ring->desc, 0, rx_ring->size);

	rx_ring->next_to_clean = 0;
	rx_ring->next_to_use = 0;

	IXGB_WRITE_REG(&adapter->hw, RDH, 0);
	IXGB_WRITE_REG(&adapter->hw, RDT, 0);
}

/**
 * ixgb_set_mac - Change the Ethernet Address of the NIC
 * @netdev: network interface device structure
 * @p: pointer to an address structure
 *
 * Returns 0 on success, negative on failure
 **/

static int
ixgb_set_mac(struct net_device *netdev, void *p)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	struct sockaddr *addr = p;

	if(!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);

	ixgb_rar_set(&adapter->hw, addr->sa_data, 0);

	return 0;
}

/**
 * ixgb_set_multi - Multicast and Promiscuous mode set
 * @netdev: network interface device structure
 *
 * The set_multi entry point is called whenever the multicast address
 * list or the network interface flags are updated.  This routine is
 * responsible for configuring the hardware for proper multicast,
 * promiscuous mode, and all-multi behavior.
 **/

static void
ixgb_set_multi(struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	struct ixgb_hw *hw = &adapter->hw;
	struct dev_mc_list *mc_ptr;
	uint32_t rctl;
	int i;

	/* Check for Promiscuous and All Multicast modes */

	rctl = IXGB_READ_REG(hw, RCTL);

	if(netdev->flags & IFF_PROMISC) {
		rctl |= (IXGB_RCTL_UPE | IXGB_RCTL_MPE);
	} else if(netdev->flags & IFF_ALLMULTI) {
		rctl |= IXGB_RCTL_MPE;
		rctl &= ~IXGB_RCTL_UPE;
	} else {
		rctl &= ~(IXGB_RCTL_UPE | IXGB_RCTL_MPE);
	}

	if(netdev->mc_count > IXGB_MAX_NUM_MULTICAST_ADDRESSES) {
		rctl |= IXGB_RCTL_MPE;
		IXGB_WRITE_REG(hw, RCTL, rctl);
	} else {
		uint8_t mta[netdev->mc_count * IXGB_ETH_LENGTH_OF_ADDRESS];

		IXGB_WRITE_REG(hw, RCTL, rctl);

		for(i = 0, mc_ptr = netdev->mc_list; mc_ptr;
			i++, mc_ptr = mc_ptr->next)
			memcpy(&mta[i * IXGB_ETH_LENGTH_OF_ADDRESS],
				   mc_ptr->dmi_addr, IXGB_ETH_LENGTH_OF_ADDRESS);

		ixgb_mc_addr_list_update(hw, mta, netdev->mc_count, 0);
	}
}

/**
 * ixgb_watchdog - Timer Call-back
 * @data: pointer to netdev cast into an unsigned long
 **/

static void
ixgb_watchdog(unsigned long data)
{
	struct ixgb_adapter *adapter = (struct ixgb_adapter *)data;
	struct net_device *netdev = adapter->netdev;
	struct ixgb_desc_ring *txdr = &adapter->tx_ring;

	ixgb_check_for_link(&adapter->hw);

	if (ixgb_check_for_bad_link(&adapter->hw)) {
		/* force the reset path */
		netif_stop_queue(netdev);
	}

	if(adapter->hw.link_up) {
		if(!netif_carrier_ok(netdev)) {
			printk(KERN_INFO "ixgb: %s NIC Link is Up %d Mbps %s\n",
				   netdev->name, 10000, "Full Duplex");
			adapter->link_speed = 10000;
			adapter->link_duplex = FULL_DUPLEX;
			netif_carrier_on(netdev);
			netif_wake_queue(netdev);
		}
	} else {
		if(netif_carrier_ok(netdev)) {
			adapter->link_speed = 0;
			adapter->link_duplex = 0;
			printk(KERN_INFO
				   "ixgb: %s NIC Link is Down\n",
				   netdev->name);
			netif_carrier_off(netdev);
			netif_stop_queue(netdev);

		}
	}

	ixgb_update_stats(adapter);

	if(!netif_carrier_ok(netdev)) {
		if(IXGB_DESC_UNUSED(txdr) + 1 < txdr->count) {
			/* We've lost link, so the controller stops DMA,
			 * but we've got queued Tx work that's never going
			 * to get done, so reset controller to flush Tx.
			 * (Do the reset outside of interrupt context). */
			schedule_work(&adapter->tx_timeout_task);
		}
	}

	/* Force detection of hung controller every watchdog period */
	adapter->detect_tx_hung = TRUE;

	/* generate an interrupt to force clean up of any stragglers */
	IXGB_WRITE_REG(&adapter->hw, ICS, IXGB_INT_TXDW);

	/* Reset the timer */
	mod_timer(&adapter->watchdog_timer, jiffies + 2 * HZ);
}

#define IXGB_TX_FLAGS_CSUM		0x00000001
#define IXGB_TX_FLAGS_VLAN		0x00000002
#define IXGB_TX_FLAGS_TSO		0x00000004

static inline int
ixgb_tso(struct ixgb_adapter *adapter, struct sk_buff *skb)
{
#ifdef NETIF_F_TSO
	struct ixgb_context_desc *context_desc;
	unsigned int i;
	uint8_t ipcss, ipcso, tucss, tucso, hdr_len;
	uint16_t ipcse, tucse, mss;
	int err;

	if(likely(skb_shinfo(skb)->tso_size)) {
		if (skb_header_cloned(skb)) {
			err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
			if (err)
				return err;
		}

		hdr_len = ((skb->h.raw - skb->data) + (skb->h.th->doff << 2));
		mss = skb_shinfo(skb)->tso_size;
		skb->nh.iph->tot_len = 0;
		skb->nh.iph->check = 0;
		skb->h.th->check = ~csum_tcpudp_magic(skb->nh.iph->saddr,
						      skb->nh.iph->daddr,
						      0, IPPROTO_TCP, 0);
		ipcss = skb->nh.raw - skb->data;
		ipcso = (void *)&(skb->nh.iph->check) - (void *)skb->data;
		ipcse = skb->h.raw - skb->data - 1;
		tucss = skb->h.raw - skb->data;
		tucso = (void *)&(skb->h.th->check) - (void *)skb->data;
		tucse = 0;

		i = adapter->tx_ring.next_to_use;
		context_desc = IXGB_CONTEXT_DESC(adapter->tx_ring, i);

		context_desc->ipcss = ipcss;
		context_desc->ipcso = ipcso;
		context_desc->ipcse = cpu_to_le16(ipcse);
		context_desc->tucss = tucss;
		context_desc->tucso = tucso;
		context_desc->tucse = cpu_to_le16(tucse);
		context_desc->mss = cpu_to_le16(mss);
		context_desc->hdr_len = hdr_len;
		context_desc->status = 0;
		context_desc->cmd_type_len = cpu_to_le32(
						  IXGB_CONTEXT_DESC_TYPE 
						| IXGB_CONTEXT_DESC_CMD_TSE
						| IXGB_CONTEXT_DESC_CMD_IP
						| IXGB_CONTEXT_DESC_CMD_TCP
						| IXGB_CONTEXT_DESC_CMD_IDE
						| (skb->len - (hdr_len)));


		if(++i == adapter->tx_ring.count) i = 0;
		adapter->tx_ring.next_to_use = i;

		return 1;
	}
#endif

	return 0;
}

static inline boolean_t
ixgb_tx_csum(struct ixgb_adapter *adapter, struct sk_buff *skb)
{
	struct ixgb_context_desc *context_desc;
	unsigned int i;
	uint8_t css, cso;

	if(likely(skb->ip_summed == CHECKSUM_HW)) {
		css = skb->h.raw - skb->data;
		cso = (skb->h.raw + skb->csum) - skb->data;

		i = adapter->tx_ring.next_to_use;
		context_desc = IXGB_CONTEXT_DESC(adapter->tx_ring, i);

		context_desc->tucss = css;
		context_desc->tucso = cso;
		context_desc->tucse = 0;
		/* zero out any previously existing data in one instruction */
		*(uint32_t *)&(context_desc->ipcss) = 0;
		context_desc->status = 0;
		context_desc->hdr_len = 0;
		context_desc->mss = 0;
		context_desc->cmd_type_len =
			cpu_to_le32(IXGB_CONTEXT_DESC_TYPE
				    | IXGB_TX_DESC_CMD_IDE);

		if(++i == adapter->tx_ring.count) i = 0;
		adapter->tx_ring.next_to_use = i;

		return TRUE;
	}

	return FALSE;
}

#define IXGB_MAX_TXD_PWR	14
#define IXGB_MAX_DATA_PER_TXD	(1<<IXGB_MAX_TXD_PWR)

static inline int
ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb,
	    unsigned int first)
{
	struct ixgb_desc_ring *tx_ring = &adapter->tx_ring;
	struct ixgb_buffer *buffer_info;
	int len = skb->len;
	unsigned int offset = 0, size, count = 0, i;
	unsigned int mss = skb_shinfo(skb)->tso_size;

	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
	unsigned int f;

	len -= skb->data_len;

	i = tx_ring->next_to_use;

	while(len) {
		buffer_info = &tx_ring->buffer_info[i];
		size = min(len, IXGB_MAX_JUMBO_FRAME_SIZE);
		/* Workaround for premature desc write-backs
		 * in TSO mode.  Append 4-byte sentinel desc */
		if(unlikely(mss && !nr_frags && size == len && size > 8))
			size -= 4;

		buffer_info->length = size;
		buffer_info->dma =
			pci_map_single(adapter->pdev,
				skb->data + offset,
				size,
				PCI_DMA_TODEVICE);
		buffer_info->time_stamp = jiffies;

		len -= size;
		offset += size;
		count++;
		if(++i == tx_ring->count) i = 0;
	}

	for(f = 0; f < nr_frags; f++) {
		struct skb_frag_struct *frag;

		frag = &skb_shinfo(skb)->frags[f];
		len = frag->size;
		offset = 0;

		while(len) {
			buffer_info = &tx_ring->buffer_info[i];
			size = min(len, IXGB_MAX_JUMBO_FRAME_SIZE);
			/* Workaround for premature desc write-backs
			 * in TSO mode.  Append 4-byte sentinel desc */
			if(unlikely(mss && (f == (nr_frags-1)) && (size == len)
			            && (size > 8)))
				size -= 4;

			buffer_info->length = size;
			buffer_info->dma =
				pci_map_page(adapter->pdev,
					frag->page,
					frag->page_offset + offset,
					size,
					PCI_DMA_TODEVICE);
			buffer_info->time_stamp = jiffies;

			len -= size;
			offset += size;
			count++;
			if(++i == tx_ring->count) i = 0;
		}
	}
	i = (i == 0) ? tx_ring->count - 1 : i - 1;
	tx_ring->buffer_info[i].skb = skb;
	tx_ring->buffer_info[first].next_to_watch = i;

	return count;
}

static inline void
ixgb_tx_queue(struct ixgb_adapter *adapter, int count, int vlan_id,int tx_flags)
{
	struct ixgb_desc_ring *tx_ring = &adapter->tx_ring;
	struct ixgb_tx_desc *tx_desc = NULL;
	struct ixgb_buffer *buffer_info;
	uint32_t cmd_type_len = adapter->tx_cmd_type;
	uint8_t status = 0;
	uint8_t popts = 0;
	unsigned int i;

	if(tx_flags & IXGB_TX_FLAGS_TSO) {
		cmd_type_len |= IXGB_TX_DESC_CMD_TSE;
		popts |= (IXGB_TX_DESC_POPTS_IXSM | IXGB_TX_DESC_POPTS_TXSM);
	}

	if(tx_flags & IXGB_TX_FLAGS_CSUM)
		popts |= IXGB_TX_DESC_POPTS_TXSM;

	if(tx_flags & IXGB_TX_FLAGS_VLAN) {
		cmd_type_len |= IXGB_TX_DESC_CMD_VLE;
	}

	i = tx_ring->next_to_use;

	while(count--) {
		buffer_info = &tx_ring->buffer_info[i];
		tx_desc = IXGB_TX_DESC(*tx_ring, i);
		tx_desc->buff_addr = cpu_to_le64(buffer_info->dma);
		tx_desc->cmd_type_len =
			cpu_to_le32(cmd_type_len | buffer_info->length);
		tx_desc->status = status;
		tx_desc->popts = popts;
		tx_desc->vlan = cpu_to_le16(vlan_id);

		if(++i == tx_ring->count) i = 0;
	}

	tx_desc->cmd_type_len |= cpu_to_le32(IXGB_TX_DESC_CMD_EOP 
				| IXGB_TX_DESC_CMD_RS );

	/* Force memory writes to complete before letting h/w
	 * know there are new descriptors to fetch.  (Only
	 * applicable for weak-ordered memory model archs,
	 * such as IA-64). */
	wmb();

	tx_ring->next_to_use = i;
	IXGB_WRITE_REG(&adapter->hw, TDT, i);
}

/* Tx Descriptors needed, worst case */
#define TXD_USE_COUNT(S) (((S) >> IXGB_MAX_TXD_PWR) + \
			 (((S) & (IXGB_MAX_DATA_PER_TXD - 1)) ? 1 : 0))
#define DESC_NEEDED TXD_USE_COUNT(IXGB_MAX_DATA_PER_TXD) + \
	MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1 \
	/* one more for TSO workaround */ + 1

static int
ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	unsigned int first;
	unsigned int tx_flags = 0;
	unsigned long flags;
	int vlan_id = 0;
	int tso;

	if(skb->len <= 0) {
		dev_kfree_skb_any(skb);
		return 0;
	}

#ifdef NETIF_F_LLTX
	local_irq_save(flags);
	if (!spin_trylock(&adapter->tx_lock)) {
		/* Collision - tell upper layer to requeue */
		local_irq_restore(flags);
		return NETDEV_TX_LOCKED;
	}
#else
	spin_lock_irqsave(&adapter->tx_lock, flags);
#endif

	if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED)) {
		netif_stop_queue(netdev);
		spin_unlock_irqrestore(&adapter->tx_lock, flags);
		return NETDEV_TX_BUSY;
	}

#ifndef NETIF_F_LLTX
	spin_unlock_irqrestore(&adapter->tx_lock, flags);
#endif

	if(adapter->vlgrp && vlan_tx_tag_present(skb)) {
		tx_flags |= IXGB_TX_FLAGS_VLAN;
		vlan_id = vlan_tx_tag_get(skb);
	}

	first = adapter->tx_ring.next_to_use;
	
	tso = ixgb_tso(adapter, skb);
	if (tso < 0) {
		dev_kfree_skb_any(skb);
#ifdef NETIF_F_LLTX
		spin_unlock_irqrestore(&adapter->tx_lock, flags);
#endif
		return NETDEV_TX_OK;
	}

	if (likely(tso))
		tx_flags |= IXGB_TX_FLAGS_TSO;
	else if(ixgb_tx_csum(adapter, skb))
		tx_flags |= IXGB_TX_FLAGS_CSUM;

	ixgb_tx_queue(adapter, ixgb_tx_map(adapter, skb, first), vlan_id,
			tx_flags);

	netdev->trans_start = jiffies;

#ifdef NETIF_F_LLTX
	/* Make sure there is space in the ring for the next send. */
	if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED))
		netif_stop_queue(netdev);

	spin_unlock_irqrestore(&adapter->tx_lock, flags);

#endif
	return NETDEV_TX_OK;
}

/**
 * ixgb_tx_timeout - Respond to a Tx Hang
 * @netdev: network interface device structure
 **/

static void
ixgb_tx_timeout(struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);

	/* Do the reset outside of interrupt context */
	schedule_work(&adapter->tx_timeout_task);
}

static void
ixgb_tx_timeout_task(struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);

	ixgb_down(adapter, TRUE);
	ixgb_up(adapter);
}

/**
 * ixgb_get_stats - Get System Network Statistics
 * @netdev: network interface device structure
 *
 * Returns the address of the device statistics structure.
 * The statistics are actually updated from the timer callback.
 **/

static struct net_device_stats *
ixgb_get_stats(struct net_device *netdev)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);

	return &adapter->net_stats;
}

/**
 * ixgb_change_mtu - Change the Maximum Transfer Unit
 * @netdev: network interface device structure
 * @new_mtu: new value for maximum frame size
 *
 * Returns 0 on success, negative on failure
 **/

static int
ixgb_change_mtu(struct net_device *netdev, int new_mtu)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	int max_frame = new_mtu + ENET_HEADER_SIZE + ENET_FCS_LENGTH;
	int old_max_frame = netdev->mtu + ENET_HEADER_SIZE + ENET_FCS_LENGTH;


	if((max_frame < IXGB_MIN_ENET_FRAME_SIZE_WITHOUT_FCS + ENET_FCS_LENGTH)
	   || (max_frame > IXGB_MAX_JUMBO_FRAME_SIZE + ENET_FCS_LENGTH)) {
		IXGB_ERR("Invalid MTU setting\n");
		return -EINVAL;
	}

	if((max_frame <= IXGB_MAX_ENET_FRAME_SIZE_WITHOUT_FCS + ENET_FCS_LENGTH)
	   || (max_frame <= IXGB_RXBUFFER_2048)) {
		adapter->rx_buffer_len = IXGB_RXBUFFER_2048;

	} else if(max_frame <= IXGB_RXBUFFER_4096) {
		adapter->rx_buffer_len = IXGB_RXBUFFER_4096;

	} else if(max_frame <= IXGB_RXBUFFER_8192) {
		adapter->rx_buffer_len = IXGB_RXBUFFER_8192;

	} else {
		adapter->rx_buffer_len = IXGB_RXBUFFER_16384;
	}

	netdev->mtu = new_mtu;

	if(old_max_frame != max_frame && netif_running(netdev)) {

		ixgb_down(adapter, TRUE);
		ixgb_up(adapter);
	}

	return 0;
}

/**
 * ixgb_update_stats - Update the board statistics counters.
 * @adapter: board private structure
 **/

void
ixgb_update_stats(struct ixgb_adapter *adapter)
{
	struct net_device *netdev = adapter->netdev;

	if((netdev->flags & IFF_PROMISC) || (netdev->flags & IFF_ALLMULTI) ||
	   (netdev->mc_count > IXGB_MAX_NUM_MULTICAST_ADDRESSES)) {
		u64 multi = IXGB_READ_REG(&adapter->hw, MPRCL);
		u32 bcast_l = IXGB_READ_REG(&adapter->hw, BPRCL);
		u32 bcast_h = IXGB_READ_REG(&adapter->hw, BPRCH);
		u64 bcast = ((u64)bcast_h << 32) | bcast_l; 

		multi |= ((u64)IXGB_READ_REG(&adapter->hw, MPRCH) << 32);
		/* fix up multicast stats by removing broadcasts */
		if(multi >= bcast)
			multi -= bcast;
		
		adapter->stats.mprcl += (multi & 0xFFFFFFFF);
		adapter->stats.mprch += (multi >> 32);
		adapter->stats.bprcl += bcast_l; 
		adapter->stats.bprch += bcast_h;
	} else {
		adapter->stats.mprcl += IXGB_READ_REG(&adapter->hw, MPRCL);
		adapter->stats.mprch += IXGB_READ_REG(&adapter->hw, MPRCH);
		adapter->stats.bprcl += IXGB_READ_REG(&adapter->hw, BPRCL);
		adapter->stats.bprch += IXGB_READ_REG(&adapter->hw, BPRCH);
	}
	adapter->stats.tprl += IXGB_READ_REG(&adapter->hw, TPRL);
	adapter->stats.tprh += IXGB_READ_REG(&adapter->hw, TPRH);
	adapter->stats.gprcl += IXGB_READ_REG(&adapter->hw, GPRCL);
	adapter->stats.gprch += IXGB_READ_REG(&adapter->hw, GPRCH);
	adapter->stats.uprcl += IXGB_READ_REG(&adapter->hw, UPRCL);
	adapter->stats.uprch += IXGB_READ_REG(&adapter->hw, UPRCH);
	adapter->stats.vprcl += IXGB_READ_REG(&adapter->hw, VPRCL);
	adapter->stats.vprch += IXGB_READ_REG(&adapter->hw, VPRCH);
	adapter->stats.jprcl += IXGB_READ_REG(&adapter->hw, JPRCL);
	adapter->stats.jprch += IXGB_READ_REG(&adapter->hw, JPRCH);
	adapter->stats.gorcl += IXGB_READ_REG(&adapter->hw, GORCL);
	adapter->stats.gorch += IXGB_READ_REG(&adapter->hw, GORCH);
	adapter->stats.torl += IXGB_READ_REG(&adapter->hw, TORL);
	adapter->stats.torh += IXGB_READ_REG(&adapter->hw, TORH);
	adapter->stats.rnbc += IXGB_READ_REG(&adapter->hw, RNBC);
	adapter->stats.ruc += IXGB_READ_REG(&adapter->hw, RUC);
	adapter->stats.roc += IXGB_READ_REG(&adapter->hw, ROC);
	adapter->stats.rlec += IXGB_READ_REG(&adapter->hw, RLEC);
	adapter->stats.crcerrs += IXGB_READ_REG(&adapter->hw, CRCERRS);
	adapter->stats.icbc += IXGB_READ_REG(&adapter->hw, ICBC);
	adapter->stats.ecbc += IXGB_READ_REG(&adapter->hw, ECBC);
	adapter->stats.mpc += IXGB_READ_REG(&adapter->hw, MPC);
	adapter->stats.tptl += IXGB_READ_REG(&adapter->hw, TPTL);
	adapter->stats.tpth += IXGB_READ_REG(&adapter->hw, TPTH);
	adapter->stats.gptcl += IXGB_READ_REG(&adapter->hw, GPTCL);
	adapter->stats.gptch += IXGB_READ_REG(&adapter->hw, GPTCH);
	adapter->stats.bptcl += IXGB_READ_REG(&adapter->hw, BPTCL);
	adapter->stats.bptch += IXGB_READ_REG(&adapter->hw, BPTCH);
	adapter->stats.mptcl += IXGB_READ_REG(&adapter->hw, MPTCL);
	adapter->stats.mptch += IXGB_READ_REG(&adapter->hw, MPTCH);
	adapter->stats.uptcl += IXGB_READ_REG(&adapter->hw, UPTCL);
	adapter->stats.uptch += IXGB_READ_REG(&adapter->hw, UPTCH);
	adapter->stats.vptcl += IXGB_READ_REG(&adapter->hw, VPTCL);
	adapter->stats.vptch += IXGB_READ_REG(&adapter->hw, VPTCH);
	adapter->stats.jptcl += IXGB_READ_REG(&adapter->hw, JPTCL);
	adapter->stats.jptch += IXGB_READ_REG(&adapter->hw, JPTCH);
	adapter->stats.gotcl += IXGB_READ_REG(&adapter->hw, GOTCL);
	adapter->stats.gotch += IXGB_READ_REG(&adapter->hw, GOTCH);
	adapter->stats.totl += IXGB_READ_REG(&adapter->hw, TOTL);
	adapter->stats.toth += IXGB_READ_REG(&adapter->hw, TOTH);
	adapter->stats.dc += IXGB_READ_REG(&adapter->hw, DC);
	adapter->stats.plt64c += IXGB_READ_REG(&adapter->hw, PLT64C);
	adapter->stats.tsctc += IXGB_READ_REG(&adapter->hw, TSCTC);
	adapter->stats.tsctfc += IXGB_READ_REG(&adapter->hw, TSCTFC);
	adapter->stats.ibic += IXGB_READ_REG(&adapter->hw, IBIC);
	adapter->stats.rfc += IXGB_READ_REG(&adapter->hw, RFC);
	adapter->stats.lfc += IXGB_READ_REG(&adapter->hw, LFC);
	adapter->stats.pfrc += IXGB_READ_REG(&adapter->hw, PFRC);
	adapter->stats.pftc += IXGB_READ_REG(&adapter->hw, PFTC);
	adapter->stats.mcfrc += IXGB_READ_REG(&adapter->hw, MCFRC);
	adapter->stats.mcftc += IXGB_READ_REG(&adapter->hw, MCFTC);
	adapter->stats.xonrxc += IXGB_READ_REG(&adapter->hw, XONRXC);
	adapter->stats.xontxc += IXGB_READ_REG(&adapter->hw, XONTXC);
	adapter->stats.xoffrxc += IXGB_READ_REG(&adapter->hw, XOFFRXC);
	adapter->stats.xofftxc += IXGB_READ_REG(&adapter->hw, XOFFTXC);
	adapter->stats.rjc += IXGB_READ_REG(&adapter->hw, RJC);

	/* Fill out the OS statistics structure */

	adapter->net_stats.rx_packets = adapter->stats.gprcl;
	adapter->net_stats.tx_packets = adapter->stats.gptcl;
	adapter->net_stats.rx_bytes = adapter->stats.gorcl;
	adapter->net_stats.tx_bytes = adapter->stats.gotcl;
	adapter->net_stats.multicast = adapter->stats.mprcl;
	adapter->net_stats.collisions = 0;

	/* ignore RLEC as it reports errors for padded (<64bytes) frames
	 * with a length in the type/len field */
	adapter->net_stats.rx_errors =
	    /* adapter->stats.rnbc + */ adapter->stats.crcerrs +
	    adapter->stats.ruc +
	    adapter->stats.roc /*+ adapter->stats.rlec */  +
	    adapter->stats.icbc +
	    adapter->stats.ecbc + adapter->stats.mpc;

	/* see above
	 * adapter->net_stats.rx_length_errors = adapter->stats.rlec;
	 */

	adapter->net_stats.rx_crc_errors = adapter->stats.crcerrs;
	adapter->net_stats.rx_fifo_errors = adapter->stats.mpc;
	adapter->net_stats.rx_missed_errors = adapter->stats.mpc;
	adapter->net_stats.rx_over_errors = adapter->stats.mpc;

	adapter->net_stats.tx_errors = 0;
	adapter->net_stats.rx_frame_errors = 0;
	adapter->net_stats.tx_aborted_errors = 0;
	adapter->net_stats.tx_carrier_errors = 0;
	adapter->net_stats.tx_fifo_errors = 0;
	adapter->net_stats.tx_heartbeat_errors = 0;
	adapter->net_stats.tx_window_errors = 0;
}

#define IXGB_MAX_INTR 10
/**
 * ixgb_intr - Interrupt Handler
 * @irq: interrupt number
 * @data: pointer to a network interface device structure
 * @pt_regs: CPU registers structure
 **/

static irqreturn_t
ixgb_intr(int irq, void *data, struct pt_regs *regs)
{
	struct net_device *netdev = data;
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	struct ixgb_hw *hw = &adapter->hw;
	uint32_t icr = IXGB_READ_REG(hw, ICR);
#ifndef CONFIG_IXGB_NAPI
	unsigned int i;
#endif

	if(unlikely(!icr))
		return IRQ_NONE;  /* Not our interrupt */

	if(unlikely(icr & (IXGB_INT_RXSEQ | IXGB_INT_LSC))) {
		mod_timer(&adapter->watchdog_timer, jiffies);
	}

#ifdef CONFIG_IXGB_NAPI
	if(netif_rx_schedule_prep(netdev)) {

		/* Disable interrupts and register for poll. The flush 
		  of the posted write is intentionally left out.
		*/

		atomic_inc(&adapter->irq_sem);
		IXGB_WRITE_REG(&adapter->hw, IMC, ~0);
		__netif_rx_schedule(netdev);
	}
#else
	/* yes, that is actually a & and it is meant to make sure that
	 * every pass through this for loop checks both receive and
	 * transmit queues for completed descriptors, intended to
	 * avoid starvation issues and assist tx/rx fairness. */
	for(i = 0; i < IXGB_MAX_INTR; i++)
		if(!ixgb_clean_rx_irq(adapter) &
		   !ixgb_clean_tx_irq(adapter))
			break;
#endif 
	return IRQ_HANDLED;
}

#ifdef CONFIG_IXGB_NAPI
/**
 * ixgb_clean - NAPI Rx polling callback
 * @adapter: board private structure
 **/

static int
ixgb_clean(struct net_device *netdev, int *budget)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	int work_to_do = min(*budget, netdev->quota);
	int tx_cleaned;
	int work_done = 0;

	tx_cleaned = ixgb_clean_tx_irq(adapter);
	ixgb_clean_rx_irq(adapter, &work_done, work_to_do);

	*budget -= work_done;
	netdev->quota -= work_done;

	/* if no Tx and not enough Rx work done, exit the polling mode */
	if((!tx_cleaned && (work_done == 0)) || !netif_running(netdev)) {
		netif_rx_complete(netdev);
		ixgb_irq_enable(adapter);
		return 0;
	}

	return 1;
}
#endif

/**
 * ixgb_clean_tx_irq - Reclaim resources after transmit completes
 * @adapter: board private structure
 **/

static boolean_t
ixgb_clean_tx_irq(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *tx_ring = &adapter->tx_ring;
	struct net_device *netdev = adapter->netdev;
	struct ixgb_tx_desc *tx_desc, *eop_desc;
	struct ixgb_buffer *buffer_info;
	unsigned int i, eop;
	boolean_t cleaned = FALSE;

	i = tx_ring->next_to_clean;
	eop = tx_ring->buffer_info[i].next_to_watch;
	eop_desc = IXGB_TX_DESC(*tx_ring, eop);

	while(eop_desc->status & IXGB_TX_DESC_STATUS_DD) {

		for(cleaned = FALSE; !cleaned; ) {
			tx_desc = IXGB_TX_DESC(*tx_ring, i);
			buffer_info = &tx_ring->buffer_info[i];

			if (tx_desc->popts
			    & (IXGB_TX_DESC_POPTS_TXSM |
			       IXGB_TX_DESC_POPTS_IXSM))
				adapter->hw_csum_tx_good++;

			ixgb_unmap_and_free_tx_resource(adapter, buffer_info);

			*(uint32_t *)&(tx_desc->status) = 0;

			cleaned = (i == eop);
			if(++i == tx_ring->count) i = 0;
		}

		eop = tx_ring->buffer_info[i].next_to_watch;
		eop_desc = IXGB_TX_DESC(*tx_ring, eop);
	}

	tx_ring->next_to_clean = i;

	spin_lock(&adapter->tx_lock);
	if(cleaned && netif_queue_stopped(netdev) && netif_carrier_ok(netdev) &&
	   (IXGB_DESC_UNUSED(tx_ring) > IXGB_TX_QUEUE_WAKE)) {

		netif_wake_queue(netdev);
	}
	spin_unlock(&adapter->tx_lock);

	if(adapter->detect_tx_hung) {
		/* detect a transmit hang in hardware, this serializes the
		 * check with the clearing of time_stamp and movement of i */
		adapter->detect_tx_hung = FALSE;
		if(tx_ring->buffer_info[i].dma &&
		   time_after(jiffies, tx_ring->buffer_info[i].time_stamp + HZ)
		   && !(IXGB_READ_REG(&adapter->hw, STATUS) &
			IXGB_STATUS_TXOFF))
			netif_stop_queue(netdev);
	}

	return cleaned;
}

/**
 * ixgb_rx_checksum - Receive Checksum Offload for 82597.
 * @adapter: board private structure
 * @rx_desc: receive descriptor
 * @sk_buff: socket buffer with received data
 **/

static inline void
ixgb_rx_checksum(struct ixgb_adapter *adapter,
		 struct ixgb_rx_desc *rx_desc,
		 struct sk_buff *skb)
{
	/* Ignore Checksum bit is set OR
	 * TCP Checksum has not been calculated
	 */
	if((rx_desc->status & IXGB_RX_DESC_STATUS_IXSM) ||
	   (!(rx_desc->status & IXGB_RX_DESC_STATUS_TCPCS))) {
		skb->ip_summed = CHECKSUM_NONE;
		return;
	}

	/* At this point we know the hardware did the TCP checksum */
	/* now look at the TCP checksum error bit */
	if(rx_desc->errors & IXGB_RX_DESC_ERRORS_TCPE) {
		/* let the stack verify checksum errors */
		skb->ip_summed = CHECKSUM_NONE;
		adapter->hw_csum_rx_error++;
	} else {
		/* TCP checksum is good */
		skb->ip_summed = CHECKSUM_UNNECESSARY;
		adapter->hw_csum_rx_good++;
	}
}

/**
 * ixgb_clean_rx_irq - Send received data up the network stack,
 * @adapter: board private structure
 **/

static boolean_t
#ifdef CONFIG_IXGB_NAPI
ixgb_clean_rx_irq(struct ixgb_adapter *adapter, int *work_done, int work_to_do)
#else
ixgb_clean_rx_irq(struct ixgb_adapter *adapter)
#endif
{
	struct ixgb_desc_ring *rx_ring = &adapter->rx_ring;
	struct net_device *netdev = adapter->netdev;
	struct pci_dev *pdev = adapter->pdev;
	struct ixgb_rx_desc *rx_desc, *next_rxd;
	struct ixgb_buffer *buffer_info, *next_buffer, *next2_buffer;
	uint32_t length;
	unsigned int i, j;
	boolean_t cleaned = FALSE;

	i = rx_ring->next_to_clean;
	rx_desc = IXGB_RX_DESC(*rx_ring, i);
	buffer_info = &rx_ring->buffer_info[i];

	while(rx_desc->status & IXGB_RX_DESC_STATUS_DD) {
		struct sk_buff *skb, *next_skb;
		u8 status;

#ifdef CONFIG_IXGB_NAPI
		if(*work_done >= work_to_do)
			break;

		(*work_done)++;
#endif
		status = rx_desc->status;
		skb = buffer_info->skb;

		prefetch(skb->data);

		if(++i == rx_ring->count) i = 0;
		next_rxd = IXGB_RX_DESC(*rx_ring, i);
		prefetch(next_rxd);

		if((j = i + 1) == rx_ring->count) j = 0;
		next2_buffer = &rx_ring->buffer_info[j];
		prefetch(next2_buffer);

		next_buffer = &rx_ring->buffer_info[i];
		next_skb = next_buffer->skb;
		prefetch(next_skb);

		cleaned = TRUE;

		pci_unmap_single(pdev,
				 buffer_info->dma,
				 buffer_info->length,
				 PCI_DMA_FROMDEVICE);

		length = le16_to_cpu(rx_desc->length);

		if(unlikely(!(status & IXGB_RX_DESC_STATUS_EOP))) {

			/* All receives must fit into a single buffer */

			IXGB_DBG("Receive packet consumed multiple buffers "
					 "length<%x>\n", length);

			dev_kfree_skb_irq(skb);
			goto rxdesc_done;
		}

		if (unlikely(rx_desc->errors
			     & (IXGB_RX_DESC_ERRORS_CE | IXGB_RX_DESC_ERRORS_SE
				| IXGB_RX_DESC_ERRORS_P |
				IXGB_RX_DESC_ERRORS_RXE))) {

			dev_kfree_skb_irq(skb);
			goto rxdesc_done;
		}

		/* Good Receive */
		skb_put(skb, length);

		/* Receive Checksum Offload */
		ixgb_rx_checksum(adapter, rx_desc, skb);

		skb->protocol = eth_type_trans(skb, netdev);
#ifdef CONFIG_IXGB_NAPI
		if(adapter->vlgrp && (status & IXGB_RX_DESC_STATUS_VP)) {
			vlan_hwaccel_receive_skb(skb, adapter->vlgrp,
				le16_to_cpu(rx_desc->special) &
					IXGB_RX_DESC_SPECIAL_VLAN_MASK);
		} else {
			netif_receive_skb(skb);
		}
#else /* CONFIG_IXGB_NAPI */
		if(adapter->vlgrp && (status & IXGB_RX_DESC_STATUS_VP)) {
			vlan_hwaccel_rx(skb, adapter->vlgrp,
				le16_to_cpu(rx_desc->special) &
					IXGB_RX_DESC_SPECIAL_VLAN_MASK);
		} else {
			netif_rx(skb);
		}
#endif /* CONFIG_IXGB_NAPI */
		netdev->last_rx = jiffies;

rxdesc_done:
		/* clean up descriptor, might be written over by hw */
		rx_desc->status = 0;
		buffer_info->skb = NULL;

		/* use prefetched values */
		rx_desc = next_rxd;
		buffer_info = next_buffer;
	}

	rx_ring->next_to_clean = i;

	ixgb_alloc_rx_buffers(adapter);

	return cleaned;
}

/**
 * ixgb_alloc_rx_buffers - Replace used receive buffers
 * @adapter: address of board private structure
 **/

static void
ixgb_alloc_rx_buffers(struct ixgb_adapter *adapter)
{
	struct ixgb_desc_ring *rx_ring = &adapter->rx_ring;
	struct net_device *netdev = adapter->netdev;
	struct pci_dev *pdev = adapter->pdev;
	struct ixgb_rx_desc *rx_desc;
	struct ixgb_buffer *buffer_info;
	struct sk_buff *skb;
	unsigned int i;
	int num_group_tail_writes;
	long cleancount;

	i = rx_ring->next_to_use;
	buffer_info = &rx_ring->buffer_info[i];
	cleancount = IXGB_DESC_UNUSED(rx_ring);

	num_group_tail_writes = IXGB_RX_BUFFER_WRITE;

	/* leave three descriptors unused */
	while(--cleancount > 2) {
		rx_desc = IXGB_RX_DESC(*rx_ring, i);

		skb = dev_alloc_skb(adapter->rx_buffer_len + NET_IP_ALIGN);

		if(unlikely(!skb)) {
			/* Better luck next round */
			break;
		}

		/* Make buffer alignment 2 beyond a 16 byte boundary
		 * this will result in a 16 byte aligned IP header after
		 * the 14 byte MAC header is removed
		 */
		skb_reserve(skb, NET_IP_ALIGN);

		skb->dev = netdev;

		buffer_info->skb = skb;
		buffer_info->length = adapter->rx_buffer_len;
		buffer_info->dma =
			pci_map_single(pdev,
				   skb->data,
				   adapter->rx_buffer_len,
				   PCI_DMA_FROMDEVICE);

		rx_desc->buff_addr = cpu_to_le64(buffer_info->dma);
		/* guarantee DD bit not set now before h/w gets descriptor
		 * this is the rest of the workaround for h/w double 
		 * writeback. */
		rx_desc->status = 0;

		if((i & ~(num_group_tail_writes- 1)) == i) {
			/* Force memory writes to complete before letting h/w
			 * know there are new descriptors to fetch.  (Only
			 * applicable for weak-ordered memory model archs,
			 * such as IA-64). */
			wmb();

			IXGB_WRITE_REG(&adapter->hw, RDT, i);
		}

		if(++i == rx_ring->count) i = 0;
		buffer_info = &rx_ring->buffer_info[i];
	}

	rx_ring->next_to_use = i;
}

/**
 * ixgb_vlan_rx_register - enables or disables vlan tagging/stripping.
 * 
 * @param netdev network interface device structure
 * @param grp indicates to enable or disable tagging/stripping
 **/
static void
ixgb_vlan_rx_register(struct net_device *netdev, struct vlan_group *grp)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	uint32_t ctrl, rctl;

	ixgb_irq_disable(adapter);
	adapter->vlgrp = grp;

	if(grp) {
		/* enable VLAN tag insert/strip */
		ctrl = IXGB_READ_REG(&adapter->hw, CTRL0);
		ctrl |= IXGB_CTRL0_VME;
		IXGB_WRITE_REG(&adapter->hw, CTRL0, ctrl);

		/* enable VLAN receive filtering */

		rctl = IXGB_READ_REG(&adapter->hw, RCTL);
		rctl |= IXGB_RCTL_VFE;
		rctl &= ~IXGB_RCTL_CFIEN;
		IXGB_WRITE_REG(&adapter->hw, RCTL, rctl);
	} else {
		/* disable VLAN tag insert/strip */

		ctrl = IXGB_READ_REG(&adapter->hw, CTRL0);
		ctrl &= ~IXGB_CTRL0_VME;
		IXGB_WRITE_REG(&adapter->hw, CTRL0, ctrl);

		/* disable VLAN filtering */

		rctl = IXGB_READ_REG(&adapter->hw, RCTL);
		rctl &= ~IXGB_RCTL_VFE;
		IXGB_WRITE_REG(&adapter->hw, RCTL, rctl);
	}

	ixgb_irq_enable(adapter);
}

static void
ixgb_vlan_rx_add_vid(struct net_device *netdev, uint16_t vid)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	uint32_t vfta, index;

	/* add VID to filter table */

	index = (vid >> 5) & 0x7F;
	vfta = IXGB_READ_REG_ARRAY(&adapter->hw, VFTA, index);
	vfta |= (1 << (vid & 0x1F));
	ixgb_write_vfta(&adapter->hw, index, vfta);
}

static void
ixgb_vlan_rx_kill_vid(struct net_device *netdev, uint16_t vid)
{
	struct ixgb_adapter *adapter = netdev_priv(netdev);
	uint32_t vfta, index;

	ixgb_irq_disable(adapter);

	if(adapter->vlgrp)
		adapter->vlgrp->vlan_devices[vid] = NULL;

	ixgb_irq_enable(adapter);

	/* remove VID from filter table*/

	index = (vid >> 5) & 0x7F;
	vfta = IXGB_READ_REG_ARRAY(&adapter->hw, VFTA, index);
	vfta &= ~(1 << (vid & 0x1F));
	ixgb_write_vfta(&adapter->hw, index, vfta);
}

static void
ixgb_restore_vlan(struct ixgb_adapter *adapter)
{
	ixgb_vlan_rx_register(adapter->netdev, adapter->vlgrp);

	if(adapter->vlgrp) {
		uint16_t vid;
		for(vid = 0; vid < VLAN_GROUP_ARRAY_LEN; vid++) {
			if(!adapter->vlgrp->vlan_devices[vid])
				continue;
			ixgb_vlan_rx_add_vid(adapter->netdev, vid);
		}
	}
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/*
 * Polling 'interrupt' - used by things like netconsole to send skbs
 * without having to re-enable interrupts. It's not called while
 * the interrupt routine is executing.
 */

static void ixgb_netpoll(struct net_device *dev)
{
	struct ixgb_adapter *adapter = dev->priv;

	disable_irq(adapter->pdev->irq);
	ixgb_intr(adapter->pdev->irq, dev, NULL);
	enable_irq(adapter->pdev->irq);
}
#endif

/* ixgb_main.c */